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CHEMISTRY (584 journals)            First | 1 2 3 4 5 6 | Last

Journal of Catalysts     Open Access  
Journal of Chemical & Engineering Data     Full-text available via subscription   (Followers: 11)
Journal of Chemical and Biological Interfaces     Full-text available via subscription  
Journal of Chemical Education     Full-text available via subscription   (Followers: 18)
Journal of Chemical Health Risks     Open Access   (Followers: 2)
Journal of Chemical Information and Modeling     Full-text available via subscription   (Followers: 6)
Journal of Chemical Research     Full-text available via subscription   (Followers: 5)
Journal of Chemical Science and Technology     Open Access   (Followers: 3)
Journal of Chemical Sciences     Partially Free   (Followers: 17)
Journal of Chemical Theory and Computation     Full-text available via subscription   (Followers: 13)
Journal of Cheminformatics     Open Access   (Followers: 1)
Journal of Chemistry     Open Access   (Followers: 3)
Journal of Chemometrics     Hybrid Journal   (Followers: 10)
Journal of Chromatography A     Hybrid Journal   (Followers: 54)
Journal of Clinical Toxicology     Open Access   (Followers: 1)
Journal of Colloid and Interface Science     Hybrid Journal   (Followers: 14)
Journal of Computational Chemistry     Hybrid Journal   (Followers: 15)
Journal of Coordination Chemistry     Hybrid Journal   (Followers: 1)
Journal of Dispersion Science and Technology     Hybrid Journal  
Journal of Encapsulation and Adsorption Sciences     Open Access   (Followers: 4)
Journal of Environmental Chemistry and Ecotoxicology     Open Access   (Followers: 2)
Journal of Flow Chemistry     Full-text available via subscription   (Followers: 1)
Journal of Fluorescence     Hybrid Journal   (Followers: 4)
Journal of Fluorine Chemistry     Hybrid Journal   (Followers: 6)
Journal of Fuel Chemistry and Technology     Full-text available via subscription   (Followers: 5)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 7)
Journal of Heterocyclic Chemistry     Hybrid Journal   (Followers: 5)
Journal of Immunoassay and Immunochemistry     Hybrid Journal   (Followers: 3)
Journal of Inclusion Phenomena and Macrocyclic Chemistry     Hybrid Journal   (Followers: 1)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 2)
Journal of Labelled Compounds and Radiopharmaceuticals     Hybrid Journal   (Followers: 1)
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry     Hybrid Journal   (Followers: 3)
Journal of Mass Spectrometry     Hybrid Journal   (Followers: 26)
Journal of Materials Chemistry A : Materials for Energy and Sustainability     Full-text available via subscription   (Followers: 23)
Journal of Materials Chemistry B : Materials for Biology and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Materials Chemistry C : Materials for Optical, Magnetic and Electronic Devices     Full-text available via subscription   (Followers: 6)
Journal of Materials Physics and Chemistry     Open Access  
Journal of Materials Research     Full-text available via subscription   (Followers: 10)
Journal of Mathematical Chemistry     Hybrid Journal   (Followers: 6)
Journal of Medicinal Chemistry     Full-text available via subscription   (Followers: 86)
Journal of Membrane and Separation Technology     Hybrid Journal  
Journal of Membrane Science     Hybrid Journal   (Followers: 11)
Journal of Modern Chemistry & Chemical Technology     Full-text available via subscription   (Followers: 2)
Journal of Molecular Catalysis A: Chemical     Hybrid Journal   (Followers: 3)
Journal of Molecular Graphics and Modelling     Hybrid Journal   (Followers: 4)
Journal of Molecular Liquids     Hybrid Journal   (Followers: 1)
Journal of Molecular Modeling     Hybrid Journal   (Followers: 3)
Journal of Molecular Recognition     Hybrid Journal   (Followers: 2)
Journal of Molecular Spectroscopy     Hybrid Journal   (Followers: 7)
Journal of Molecular Structure     Hybrid Journal   (Followers: 3)
Journal of Nanoparticles     Open Access  
Journal of Nanostructure in Chemistry     Open Access   (Followers: 3)
Journal of Natural Gas Chemistry     Full-text available via subscription   (Followers: 2)
Journal of Nepal Chemical Society     Open Access  
Journal of Nucleic Acids Investigation     Open Access   (Followers: 2)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1)
Journal of Organometallic Chemistry     Hybrid Journal   (Followers: 13)
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Journal of Polymer & Composites     Full-text available via subscription   (Followers: 4)
Journal of Polymer and Biopolymer Physics Chemistry     Open Access   (Followers: 2)
Journal of Polymer Science Part A: Polymer Chemistry     Hybrid Journal   (Followers: 124)
Journal of Polymers     Open Access   (Followers: 1)
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 1)
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 11)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 14)
Journal of Solution Chemistry     Hybrid Journal   (Followers: 4)
Journal of Structural Chemistry     Hybrid Journal  
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 2)
Journal of Superhard Materials     Hybrid Journal   (Followers: 1)
Journal of Surfactants and Detergents     Hybrid Journal   (Followers: 5)
Journal of Systems Chemistry     Open Access  
Journal of Taibah University for Science     Open Access  
Journal of the American Chemical Society     Full-text available via subscription   (Followers: 219)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 23)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 1)
Journal of the Bangladesh Chemical Society     Open Access  
Journal of the Chilean Chemical Society     Open Access   (Followers: 1)
Journal of the Iranian Chemical Society     Hybrid Journal  
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal   (Followers: 1)
Journal of the Mexican Chemical Society     Open Access   (Followers: 1)
Journal of Theoretical and Computational Chemistry     Hybrid Journal   (Followers: 8)
Journal of Theoretical Chemistry     Open Access  
Journal of Wood Chemistry and Technology     Hybrid Journal   (Followers: 7)
JPC - Journal of Planar Chromatography - Modern TLC     Full-text available via subscription   (Followers: 5)
Jurnal Penelitian Sains (JPS)     Open Access  
Jurnal Teknologi Informasi     Open Access   (Followers: 3)
Karbala International Journal of Modern Science     Open Access  
Kinetics and Catalysis     Hybrid Journal   (Followers: 3)
Korea-Australia Rheology Journal     Hybrid Journal  
Langmuir     Full-text available via subscription   (Followers: 42)
Latvian Journal of Chemistry     Open Access   (Followers: 1)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access  
Luminescence     Hybrid Journal   (Followers: 1)
Macromolecular Materials & Engineering     Hybrid Journal   (Followers: 5)
Macromolecular Rapid Communications     Hybrid Journal   (Followers: 5)

  First | 1 2 3 4 5 6 | Last

Journal Cover   Photochemistry and Photobiology
  [SJR: 0.764]   [H-I: 96]   [1 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0031-8655 - ISSN (Online) 1751-1097
   Published by John Wiley and Sons Homepage  [1598 journals]
  • Early Diagnosis of Diabetes Through The Eye
    • Authors: Devi Kalyan Karumanchi; Elizabeth R. Gaillard, James Dillon
      Abstract: Diabetes mellitus is a metabolic disorder characterized by high blood sugar levels which give rise to complications in the eye, kidneys and the brain. Diabetes triggers the development of ocular diseases like diabetic retinopathy and cataracts which are the leading cause of blindness around the world. The most common method for the diagnosis of diabetes involves measuring the blood sugar levels in the body. One major disadvantage of this method is the fluctuating blood sugar levels which contribute to false negative results. This leads to delay in treatment, eventually causing permanent damage to the organs. Therefore, diagnosis of diabetes at an early stage is very crucial. One biomarker for diabetes related diseases is the formation of Advanced Glycation End‐products (AGEs) that result from the Maillard reaction of proteins with glucose. α‐crystallin in the ocular lens is a small heat shock protein with no protein turnover and hence acts as a record for post‐translational modifications especially glycation which forms AGEs. We have used steady state and time resolved fluorescence measurements to study the spectroscopic changes in α‐crystallin with increase in time of glycation and the intact lenses from diabetic and non‐diabetic donors. Overall, this study was focused on developing a non‐invasive diagnostic tool for early detection of diabetes mellitus. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-27T09:37:05.150788-05:
      DOI: 10.1111/php.12524
  • More Than Just Light: Clinical Relevance of Light Perception in the
           Nosocomial Pathogen Acinetobacter baumannii and Other Members of the Genus
    • Abstract: A summary of the major findings concerning light modulation in Acinetobacter baumannii, which governs aspects related to the success of this microorganism as a nosocomial pathogen, is presented. Particularly, the evidence shows that light modulates the ability of the bacteria to persist in the environment, its virulence against eukaryotic hosts and even susceptibility to certain antibiotics. The light signal is sensed through different mechanisms, in some cases involving specialized photoreceptors of the BLUF‐type, while in others, directly by a photosensitizer molecule. We also provide new data concerning the genomic context of BLUF‐domain containing proteins within the genus Acinetobacter, as well as further insights into the mechanism of light‐mediated reduction of susceptibility to antibiotics. The overall information points towards light being a crucial stimulus in the lifestyle of members of the genus Acinetobacter as well as in other clinically‐relevant species, such as members of the ESKAPE group, playing therefore an important role in the clinical settings. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-25T02:21:14.833256-05:
      DOI: 10.1111/php.12523
  • Epigenetically Enhanced Photodynamic Therapy (ePDT) is Superior to
           Conventional Photodynamic Therapy for Inducing Apoptosis in Cutaneous
           T‐Cell Lymphoma
    • Authors: Katrin Agnes Salva; Gary S. Wood
      Abstract: Conventional photodynamic therapy with aminolevulinate (ALA‐PDT) selectively induces apoptosis in diseased cells and is highly effective for treating actinic keratoses. However, similar results are achieved only in a subset of patients with cutaneous T‐cell lymphoma (CTCL). Our previous work shows that the apoptotic resistance of CTCL correlates with low expression of death receptors like FAS, and that methotrexate upregulates FAS by inhibiting the methylation of its promoter, acting as an epigenetic derepressor that restores the susceptibility of FAS‐low CTCL to caspase 8‐mediated apoptosis. Here, we demonstrate that methotrexate increases the response of CTCL to ALA‐PDT, a concept we refer to as epigenetically enhanced PDT (ePDT). Multiple CTCL cell lines were subjected to conventional PDT versus ePDT. Apoptotic biomarkers were analyzed in situ with multispectral imaging analysis of immunostained cells, a method that is quantitative and 5x more sensitive than standard immunohistology for antigen detection. Compared to conventional PDT or methotrexate alone, ePDT led to significantly greater cell death in all CTCL cell lines tested by inducing greater activation of caspase 8‐mediated extrinsic apoptosis. Upregulation of FAS and/or TRAIL pathway components was observed in different CTCL cell lines. These findings provide a rationale for clinical trials of ePDT for CTCL. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-25T02:08:49.732602-05:
      DOI: 10.1111/php.12521
  • Caffeic Acid Inhibits UVB‐induced Inflammation and
           Photocarcinogenesis Through Activation of Peroxisome
           Proliferator‐activated Receptor‐γ in Mouse Skin
    • Authors: Agilan Balupillai; N. Rajendra Prasad, Karthikeyan Ramasamy, Ganesan Muthusamy, Mohana Shanmugham, Kanimozhi Govindasamy, Srithar Gunaseelan
      Abstract: In this study, the effect of caffeic acid (CA) on both acute and chronic UVB‐irradiation induced inflammation and photocarcinogenesis was investigated in Swiss albino mice. Animals were exposed to 180 mJ/cm2 of UVB once daily for 10 consecutive days and thrice weekly for 30 weeks for acute and chronic study, respectively. UVB exposure for 10 consecutive days showed edema formation, increased lipid peroxidation, decreased antioxidant status with activation of inflammatory molecules such as TNF‐α, IL‐6, COX‐2 and NF‐κB. Whereas, CA (15 mg/kg.b.wt.) administration before each UVB exposure decreased lipid peroxidation, inflammatory markers expression and enhanced antioxidant status probably through the activation of peroxisome proliferator‐activated receptors (PPARγ) in the mice's skin. PPARγ is considered to be a potential target for photochemoprevention because it inhibits UVB mediated inflammatory responses. In this study, UVB exposure for 30 weeks caused squamous cell carcinoma and upregulation of iNOS, VEGF, TGF‐β and down‐regulation of p53 and tumor incidence in the mice's skin. Both topical (CAT) and intraperitoneal (CAIP) treatment before each UVB exposure downregulates iNOS, VEGF, TGF‐β, upregulates p53 and reduces tumors multiplicity in the mice's skin. Thus, CA offers protection against UVB‐induced photocarcinogenesis probably through activation of anti‐inflammatory transcription factor PPARγ in the mice. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-25T02:07:36.352906-05:
      DOI: 10.1111/php.12522
  • Effect of LED Blue Light on Penicillium digitatum and Penicillium italicum
    • Abstract: Studies on the antimicrobial properties of light have considerably increased due in part to the development of resistance to actual control methods. This study investigates the potential of Light Emitting Diodes (LED) blue light for controlling Penicillium digitatum and Penicillium italicum. These fungi are the most devastating postharvest pathogens of citrus fruit and cause important losses due to contaminations and to the development of resistant strains against fungicides. The effect of different periods and quantum fluxes and of delaying light application on the growth and morphology of P. digitatum strains resistant and sensitive to fungicides and of P. italicum cultured at 20 °C was examined. Results showed that blue light controls the growth of all strains and that its efficacy increases with the quantum flux. Spore germination was always avoided by exposing the cultures to high quantum flux (700 μmolm−2s−1) for 18 h. Continuous light had an important impact on the fungus morphology and a fungicidal effect when applied at a lower quantum flux (120 μmolm−2s−1) to a growing fungus. Sensitivity to light increased with mycelium age. Results show that blue light may be a tool for P. digitatum and P. italicum infection prevention during handling of citrus fruits. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-19T10:14:23.424436-05:
      DOI: 10.1111/php.12519
  • Photodynamic Diagnosis Using 5‐Aminolevulinic Acid in 41 Biopsies
           for Primary Central Nervous System Lymphoma
    • Authors: Tetsuya Yamamoto; Eiichi Ishikawa, Shunichiro Miki, Noriaki Sakamoto, Alexander Zaboronok, Masahide Matsuda, Hiroyoshi Akutsu, Kei Nakai, Wataro Tsuruta, Akira Matsumura
      Abstract: We evaluated the feasibility of 5‐aminolevulinic acid (5‐ALA)‐mediated photodynamic diagnosis (PDD) in the biopsy for primary central nervous system lymphoma (PCNSL). 5‐ALA (20 mg/kg) was administered orally 4 hours preoperatively. Forty‐one biopsies obtained under PDD in 47 consecutive biopsies (46 patients) that were finally pathologically diagnosed as PCNSL were evaluated. Positive fluorescence was observed in 34 of those 41 biopsies (82.9%). An intraoperative pathological diagnosis (IOD) of suspected PCNSL was made in 21 of the biopsies with positive fluorescence (61.8%). However, the 8 IODs in the remaining 13 biopsies (23.5%) were not correct (atypical cell, 4; high‐grade glioma, 1; gliosis, 1; unremarkable, 2). In those 8 biopsies, PCNSL was confirmed by the final pathological diagnosis. There was no difference in the mean Mib‐1 labeling index between the biopsies with positive fluorescence (86.5%) and those without (90.0%). IOD was not performed in 6 biopsies; however, 5 of those biopsies (83.3%) showed positive fluorescence and were finally pathologically diagnosed as PCNSL. Use of PDD in biopsies for patients with suspected PCNSL is a reliable way of obtaining specimens of adequate quality for the final pathological diagnosis and may lead to improved diagnostic yield in the biopsy of PCNSL. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-16T04:43:56.708032-05:
      DOI: 10.1111/php.12510
  • Thermal Effects and Structural Changes of Photosynthetic Reaction Centers
           Characterized by Wide Frequency Band Hydrophone: Effects of Carotenoids
           and Terbutryn
    • Abstract: Photothermal characteristics and light‐induced structural (volume) changes of carotenoid‐containing and non‐containing photosynthetic reaction centers were investigated by wide frequency band hydrophone. We found that the presence of carotenoid either does not play considerable role in the light‐induced conformational movements, or these rearrangements are too slow for inducing a photoacoustic (PA) signal. The kinetic component with a few tens of microseconds, exhibited by the carotenoid‐less reaction centers, appears to be similar to that of triplet state lifetimes, identified by other methods. The binding of terbutryn to the acceptor side is shown to affect the dynamics of the reaction center (RC). Our results do not confirm large displacements or volume changes induced by the charge movements and by the charge relaxation processes in the RCs in few hundreds of microseconds time scale that accompanies the electron transfer between the primary and secondary electron acceptor quinones. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-16T04:43:33.512902-05:
      DOI: 10.1111/php.12511
  • Rethinking the Concepts of Fluence (UV Dose) and Fluence Rate: The
           Importance of Photon‐based Units – A Systemic Review
    • Abstract: After a critical review of the fundamental equations describing photobiological and photochemical processes occurring in a medium exposed to a quasi‐collimated monochromatic UV light beam, the analysis in this review is extended to analogous processes driven by polychromatic UV light, such as that emitted by medium pressure mercury‐vapor arc lamps. The analysis is based on the Second Law of Photochemistry, namely that all photochemical events must be independent, and the rate of such events must be proportional to the rate of photon absorption. A consistent application of the Second Law of Photochemistry leads to a concept change; hence it is proposed herein to use photon fluence and photon fluence rate, rather than fluence (UV dose) and fluence rate, respectively, in the analysis and interpretation of photobiological and photochemical processes. As a consequence, many equations that have been used in the past must be revised, and some experimental information (e.g., action spectra) needs to be re‐analyzed. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-16T04:43:08.689098-05:
      DOI: 10.1111/php.12512
  • Synergistic Photobactericidal Activity Based on Ultraviolet‐A
           Irradiation and Ferulic Acid Derivatives
    • Authors: Akihiro Shirai; Masato Kajiura, Takeshi Omasa
      Abstract: Ultraviolet‐A (UV‐A)‐mediated bactericidal activity was enhanced by combined treatment with trans‐ferulic acid (trans‐FA, compound 1) or its derivatives. Derivative compounds 4 and 10 contain a phenyl group or an L‐tyrosine HCl tert‐butyl ester, respectively, linked to the carboxyl group of trans‐FA. Of the three compounds, 10 exhibited the highest synergistic activity in a photobactericidal assay based on treating Escherichia coli with a derivative compound and UV‐A irradiation (wavelength 350‐385 nm). Inactivation of viable cells at a 4.9 J/cm2 UV‐A fluence increased from 1.90 to 5.19 logs in the presence of 10 (100 μM); a 4.95‐log inactivation was achieved with 10 (5 μM) and a 7.4 J/cm2 UV‐A fluence. Addition of antioxidants significantly suppressed photosynergistic bactericidal activity, suggesting that reactive oxygen species (ROS) are involved in the combined bactericidal mechanism. Flow cytometry revealed that combined treatment with UV‐A and compound 10, which showed the highest photobactericidal activity, generates an excess of oxidative radicals in bacterial cells. The bactericidal activity of compound 10 may be due to electrostatic interaction between the molecule's cationic moiety and the cell surface, followed by amplification of ROS generation in the cells. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-13T02:29:52.175033-05:
      DOI: 10.1111/php.12507
  • Selective Activation of C=C Bond in Sustainable Phenolic Compounds from
           Lignin via Photooxidation: Experiment and DFT Calculations
    • Authors: Morgan Zielinski (Goldberg); Luke A. Burke, Alexander Samokhvalov
      Abstract: Lignocellulosic biomass can be converted to high‐value phenolic compounds: food additives, antioxidants, fragrances, and fine chemicals. We investigated photochemical and heterogeneous photocatalytic oxidation of two isomeric phenolic compounds from lignin, isoeugenol and eugenol, in several non‐protic solvents, for the first time by experiment and the DFT calculations. Photooxidation was conducted under ambient conditions using air, near‐UV light, and commercial P25 TiO2 photocatalyst, and the products were determined by TLC, UV‐Vis absorption spectroscopy, HPLC‐UV, and HPLC‐MS. Photochemical and photocatalytic oxidation of isoeugenol proceeds via the mild oxidative “dimerization” to produce the lignan dehydrodiisoeugenol (DHDIE), while photooxidation of eugenol does not proceed. The DFT calculations suggest a radical step‐wise mechanism for the oxidative “dimerization” of isoeugenol to DHDIE as was calculated for the first time. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-13T02:29:28.239614-05:
      DOI: 10.1111/php.12509
  • Photochemistry and Photobiology of the Spore Photoproduct: A Fifty Year
    • Authors: Peter Setlow; Lei Li
      Abstract: Fifty years ago, a new thymine dimer was discovered as the dominant DNA photolesion in UV irradiated bacterial spores [Donnellan, J. & Setlow R. (1965) Science, 149, 308‐310], which was later named the spore photoproduct (SP). Formation of SP is due to the unique environment in the spore core that features low hydration levels favoring an A‐DNA conformation, high levels of calcium dipicolinate that acts as a photosensitizer, and DNA saturation with small, acid‐soluble proteins that alters DNA structure and reduces side reactions. In vitro studies reveal that any of these factors alone can promote SP formation; however, SP formation is usually accompanied by the production of other DNA photolesions. Therefore, the nearly exclusive SP formation in spores is due to the combined effects of these three factors. SP photoreaction is proved to occur via a unique H‐atom transfer mechanism between the two involved thymine residues. Successful incorporation of SP into an oligonucleotide has been achieved via organic synthesis, which enables structural studies that reveal minor conformational changes in the SP‐containing DNA. Here, we review the progress on SP photochemistry and photobiology in the past fifty years, which indicates a very rich SP photobiology that may exist beyond endospores. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-12T03:23:10.995057-05:
      DOI: 10.1111/php.12506
  • Baicalin Protects Keratinocytes From Toll‐Like Receptor‐4
           Mediated DNA Damage and Inflammation Following Ultraviolet Irradiation
    • Authors: Wei Min; Israr Ahmad, Michelle E. Chang, Erin M. Burns, Qihong Qian, Nabiha Yusuf
      Abstract: UVB radiation contributes to both direct and indirect damage to the skin including the generation of free radicals and reactive oxygen species (ROS), inflammatory responses, immunosuppression, and gene mutations, which can ultimately lead to photocarcinogenesis. A plant‐derived flavonoid, baicalin, has been shown to have antioxidant, anti‐inflammatory, and free radical scavenging activities. Previous studies from our laboratory have shown that in murine skin, Toll like receptor‐4 (TLR4) enhanced both UVB‐induced DNA damage and inflammation. The aim of the current study is to investigate the efficacy of baicalin against TLR4‐mediated processes in the murine keratinocyte PAM 212 cell line. Our results demonstrate that treating keratinocytes with baicalin both before and after UV radiation (100 mJ/cm2) significantly inhibited the level of intracellular ROS and decreased cyclobutane pyrimidine dimers (CPDs) and 8‐Oxo‐2′‐deoxyguanosine (8‐oxo‐dG)—markers of DNA damage. Furthermore, cells treated with baicalin demonstrated an inhibition of TLR4 and its downstream signaling molecules, MyD88, TRIF, TRAF6, and IRAK4. TLR4 pathway inhibition resulted in NF‐κB inactivation and down‐regulation of iNOS and COX‐2 protein expression. Taken together, baicalin treatment effectively protected keratinocytes from UVB‐induced inflammatory damage through TLR pathway modulation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-10T02:42:37.508711-05:
      DOI: 10.1111/php.12505
  • Photoisomerization of Trans Ortho‐, Meta‐, Para‐ Nitro
           Diarylbutadienes: A Case of Regioselectivity
    • Authors: Harsha Agnihotri; Paramasivam Mahalingavelar, Veerabhadraiah Palakollu, Sriram Kanvah
      Abstract: A series of ortho, meta and para substituted trans‐nitro aryl (phenyl and pyridyl) butadienes have been synthesized and characterized. The effect of substitution and positional selectivity on their fluorescence and photoisomerization were systematically investigated. Among all dienes, meta‐ and para‐nitro phenyl substituted derivatives exhibit remarkable solvatochromic emission shifts due to intramolecular charge transfer. On the other hand, ortho derivatives undergo regioselective isomerisation upon photoexcitation in contrast to inefficient isomerization of para and meta nitro substituted dienes. Single crystal X‐ray analysis revealed existence of intramolecular hydrogen bonding between the nitro group and the hydrogen of the proximal double bond. This restricts the rotation of the proximal double bond thereby allowing regioselective isomerization. The observations were also supported by NMR spectroscopic studies. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-06T12:08:50.589709-05:
      DOI: 10.1111/php.12504
  • Dunaliella tertiolecta (Chlorophyta) Avoids Cell Death Under
           Ultraviolet Radiation (UVR) By Triggering Alternative Photoprotective
    • Abstract: The effect of different ultraviolet radiation (UVR) treatments combining PAR (P), UVA (A), and UVB (B) on the molecular physiology of Dunaliella tertiolecta was studied during 6 days to assess the response to chronic UVR exposure. UVR reduced cell growth but did not cause cell death, as shown by the absence of SYTOX Green labelling and cellular morphology. However, caspase‐like enzymatic activities (CLs), (cell death proteases), were active even though the cells were not dying. Maximal quantum yield of fluorescence (Fv/Fm) and photosynthetic electron transport rate (ETR) dropped. Decreased non‐photochemical quenching (NPQ) paralleled a drop in xanthophyll cycle de‐epoxidation under UVB. Reactive oxygen species (ROS) and D1 protein accumulation were inversely correlated. PAB exhibited elevated ROS production at earlier times. Once ROS decayed, D1 protein recovered 2‐fold compared with P and PA at later stages. Therefore PsbA gene was still transcribed, suggesting ROS involvement in D1 recovery by its direct effect on mRNA‐translation. We add evidence of an UVB‐induced positive effect on the cells when P is present, providing photoprotection and resilience, by means of D1 repair. This allowed cells to survive. The photoprotective mechanisms described here (which are counterintuitive in principle) conform to an important ecophysiological response regarding light stress acclimation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-30T03:39:30.730181-05:
      DOI: 10.1111/php.12502
  • Noninvasive Optical Imaging of UV‐Induced Squamous Cell Carcinoma in
           Murine Skin: Studies of Early Tumor Development and Vitamin D Enhancement
           of Protoporphyrin IX Production
    • Authors: Kishore R. Rollakanti; Sanjay Anand, Scott C. Davis, Brian W. Pogue, Edward V. Maytin
      Abstract: Better noninvasive techniques are needed to monitor protoporphyrin IX (PpIX) levels before and during photodynamic therapy (PDT) of squamous cell carcinoma (SCC) of the skin. Our aim was to evaluate: (1) multispectral fluorescent imaging of ultraviolet light (UV)‐induced cancer and precancer in a mouse model of SCC; (2) multispectral imaging and probe‐based fluorescence detection as a tool to study Vitamin D (VD) effects on aminolevulinic acid (ALA)‐induced PpIX synthesis. Dorsal skin of hairless mice was imaged weekly during a 24‐week UV carcinogenesis protocol. Hot spots of PpIX fluorescence were detectable by multispectral imaging beginning at 14 weeks of UV exposure. Many hot spots disappeared after cessation of UV at week 20, but others persisted or became visible after week 20, and corresponded to tumors that eventually became visible by eye. In SCC‐bearing mice pretreated with topical VD before ALA application, our optical techniques confirmed that VD preconditioning induces a tumor‐selective increase in PpIX levels. Fluorescence‐based optical imaging of PpIX is a promising tool for detecting early SCC lesions of the skin. Pretreatment with VD can increase the ability to detect early tumors, providing a potential new way to improve efficacy of ALA‐PDT. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-30T03:37:29.773282-05:
      DOI: 10.1111/php.12503
  • Biochemical Characterization of the DASH‐Type Cryptochrome CryD from
           Fusarium fujikuroi
    • Abstract: Proteins from the cryptochrome/photolyase family utilize UV‐A, blue or even red light to achieve such diverse functions as repair of DNA lesions by photolyases and signaling by cryptochromes. DASH‐type cryptochromes retained the ability to repair cyclobutane pyrimidine dimers (CPDs) in single‐stranded DNA regions in vitro. However, most organisms possess conventional CPD photolyases responsible for repair of these lesions in vivo. Recent work showed that the DASH‐type cryptochrome CryD plays a regulatory role in diverse light‐dependent processes in Fusarium fujikuroi. Here we report our in vitro studies on heterologously‐expressed FfCryD. The purified protein contains N5,N10‐methenyltetrahydrofolate and flavin adenine dinucleotide as cofactors. Photoreduction and DNA photorepair experiments confirmed that FfCryD is active in light‐driven electron transfer processes. However, the protein showed comparable affinities for CPD‐comprising and undamaged DNA probes. Surprisingly, after purification, full‐length FfCryD as well as a truncated version containing only the PHR domain bound RNA which influenced their behavior in vitro. Moreover, binding of FfCryD to RNA indicates a putative role in RNA metabolism or in posttranscriptional control of gene expression. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-28T05:16:14.061427-05:
      DOI: 10.1111/php.12501
  • UV Sensitivity of Vegetative and Reproductive Tissues of Two Antarctic
           Brown Algae is Related to Differential Allocation of Phenolic Substances
    • Abstract: UV sensitivity of the vegetative and reproductive tissues of two Antarctic brown macroalgae was compared. Photosynthesis as well as the content and localization of phenolic substances were determined. Responses to UV radiation were quantified as chlorophyll fluorescence (Fv/Fm). Ascoseira mirabilis showed high UV tolerance, while in Cystosphaera jaquinotii Fv/Fm decreased by 15‐21%, the receptacles being more tolerant than the vegetative blades. The phlorotannin contents showed an opposite pattern: the soluble fraction dominated in C. jacquinotii while in A. mirabilis the insoluble fraction was more abundant. Soluble phlorotannins were higher in the reproductive than in vegetative tissues in both species. Images of tissue cross‐sections under violet‐blue light excitation confirmed a high allocation of phenolic compounds (as blue autofluorescence) in C. jacquinotii, both in reproductive and vegetative blades. The allocation and proportions of the soluble and insoluble phlorotannins could be related with the observed UV tolerance of the vegetative and reproductive tissues. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-27T09:37:30.967516-05:
      DOI: 10.1111/php.12500
  • Activation of the General Stress Response of Bacillus subtilis by Visible
    • Authors: Jeroen B van der Steen; Klaas J. Hellingwerf
      Abstract: A key challenge for microbiology is to understand how evolution has shaped the wiring of regulatory networks. This is amplified by the paucity of information of power‐spectra of physico‐chemical stimuli to which microorganisms are exposed. Future studies of genome evolution, driven by altered stimulus regimes, will therefore require a versatile signal transduction system that allows accurate signal dosing. Here we review the general stress response of Bacillus subtilis, and its upstream signal‐transduction network, as a candidate system. It can be activated by red and blue light, and by many additional stimuli. Signal integration therefore is an intricate function of this system. The blue‐light response is elicited via the photoreceptor YtvA, which forms an integral part of stressosomes, to activate expression of the stress regulon of B. subtilis. Signal transfer through this network can be assayed with reporter enzymes, while intermediate steps can be studied with live‐cell imaging of fluorescently tagged proteins. Different parts of this system have been studied in vitro, such that its computational modeling has made significant progress. One can directly relate the microscopic characteristics of YtvA with activation of the general stress regulon, making this system a very well‐suited system for network evolution studies. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-18T03:56:55.212926-05:
      DOI: 10.1111/php.12499
  • Modulation of Melanogenesis and Antioxidant Status of Melanocytes in
           Response to Phototoxic Action of Doxycycline
    • Abstract: Doxycycline is a commonly used tetracycline antibiotic showing the broad spectrum of antibacterial action. However, the use of this antibiotic is often connected with the risk of phototoxic reactions that lead to various skin disorders. One of the factors influencing the photosensitivity reactions is the melanin content in melanocytes. In this study, the impact of doxycycline and UVA irradiation on cell viability, melanogenesis and antioxidant defense system in cultured normal human epidermal melanocytes (HEMn‐DP) was examined. The exposure of cells to doxycycline and UVA radiation resulted in concentration‐dependent loss in melanocytes viability and induced melanin biosynthesis. Significant changes were stated in cellular antioxidant enzymes activity: SOD, CAT and GPx, which indicates alterations of antioxidant defense system. The results obtained in vitro may explain the mechanisms of phototoxic reactions that occur in normal human epidermal melanocytes in vivo after exposure of skin to doxycycline and UVA radiation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-18T03:56:33.97808-05:0
      DOI: 10.1111/php.12497
  • Model for Optimization of the UV‐A/Riboflavin Strengthening
           (Cross‐Linking) of the Cornea: Percolation Threshold
    • Authors: Anton Semchishen; Michael Mrochen, Vladimir Semchishen
      Abstract: To achieve the maximum level of collagen strengthening within the shortest treatment time possible, we have developed a mathematical model which is used to optimize the process of corneal cross‐linking. This model is able to predict the temporal and spatial distribution of generated cross‐links within the corneal stroma and hence the increase of the elasticity modulus. Theory predicts corneal strengthening at low radiation intensities and the absence of the strengthening effect at radiation intensities above the threshold level, which agrees with the experimental results. The model takes account of the initial riboflavin concentration and bleaching, light intensity and time of illumination. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-18T03:51:30.880917-05:
      DOI: 10.1111/php.12498
  • The Effect of pH Values on the Synthesis, Microstructure and
           Photocatalytic Activity of Ce‐Bi2O3 by a Two‐Step Hydrothermal
    • Authors: Fengjun Zhang; Wei Lu, Guosheng Xiao, Zhuojing Liu, Fanwei Xing, Cong Lyu
      Abstract: In this study, the effect of pH values on the microstructure and photocatalytic activity of Ce‐Bi2O3 under visible‐light irradiation was investigated in detail. In alkaline condition (e.g. pH = 9), the as‐prepared Ce‐Bi2O3 exhibited an agglomerated status and mesoporous structures without a long‐range order. While in weak acid condition (e.g. pH = 5), the Ce‐Bi2O3 exhibited a best morphology with irregular nanosheets. Correspondingly, it possessed largest surface area (24.641m2/g) and pore volume (9.825E‐02cm3/g). These unique nanosheets can offer an attachment for pollutant molecules and reduce the distance of electron immigration from inner to surface, thus facilitating the separation of photoelectron and hole pairs. Compared with the pure Bi2O3, the band gap of Ce‐Bi2O3 prepared at different pH was much lower. Among them, the band gap of Ce‐Bi2O3 (pH of 5) was lowest (2.61 eV). Ce‐Bi2O3 (pH of 5) exhibited as tetragonal crystal with the bismuth oxide in the form of the composites, which could reduce the band gap width or suppress the charge‐carrier recombination, subsequently possessing great photocatalytic activity for acid orange II under visible light irradiation. After two hours degradation under visible‐light, the degradation rate of acid Orange II was up to 96.44 % by Ce‐Bi2O3 prepared at pH 5. Overall, it can be concluded that the pH values had effects on the microstructure and photocatalytic activity of Ce‐Bi2O3 catalysts. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-15T03:51:23.894208-05:
      DOI: 10.1111/php.12496
  • Preparation of Silver Carbonate and Its Application as Visible
           Light‐driven Photocatalyst Without Sacrificial Reagent
    • Authors: Wei Jiang; Ya Zeng, Xiaoyan Wang, Xiaoning Yue, Shaojun Yuan, Houfang Lu, Bin Liang
      Abstract: Visible‐light driven photocatalyst is the current research focus and silver oxyacid salts with p block elements are the promising candidates. In this research, Ag2CO3 was prepared by a facile precipitation method and used to degrade the pollutants from waters. The results revealed that the silver carbonate with monoclinic structure quickly decomposed methyl orange and rhodamine B in less than 15 minutes under visible light irradiation. When it was recycled six times, the degradation of methyl orange still can reach 87% after 30 minutes. The calculated band gap of Ag2CO3 was 2.312 eV with Valence band edge potential of 2.685 eV and Conduction band 0.373 eV vs. NHE, which endowed the excellent photo‐oxidation ability of silver carbonate. Photo‐generated holes and ozone anion radicals were the primary active species in the photo‐oxidization degradation of dye. The generation of metallic silver resulted from photo‐corrosion and the consequent reduction of the ozone anion radical amount led to the performance degradation of Ag2CO3. The simple preparation method and high photocatalytic performance of Ag2CO3 increases its prospect of application in future. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-15T03:31:22.656862-05:
      DOI: 10.1111/php.12495
  • Non‐visual Opsins and the Regulation of Peripheral Clocks by Light
           and Hormones
    • Authors: Maristela O. Poletini; Bruno R. Ramos, Maria Nathalia M. Moraes, Ana Maria L. Castrucci
      Abstract: The molecular clock machinery is conserved throughout evolution. However, how environmental cues are perceived has evolved in such a way that peripheral clocks in mammals require a variety of signals, including hormones. On the other hand, in non‐mammalian cells able to directly detect light, light seems to play a major role in the synchronization of the clock. The interaction between perception of circadian light by non‐visual opsins and hormones will be discussed under the perspective of clock synchronization at the molecular level. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-14T09:12:04.696444-05:
      DOI: 10.1111/php.12494
  • Functional Characterization of a LOV‐Histidine Kinase Photoreceptor
           from Xanthomonas citri subsp. citri
    • Abstract: The blue‐light absorbing protein Xcc‐LOV from Xanthomonas citri subsp. citri is composed of a LOV‐domain, a histidine kinase (HK) and a response regulator. Spectroscopic characterization of Xcc‐LOV identified intermediates and kinetics of the protein's photocycle. Measurements of steady state and time‐resolved fluorescence allowed determination of quantum yields for triplet (ΦT = 0.68 ± 0.03) and photoproduct formation (Φ390= 0.46 ± 0.05). The lifetime for triplet decay was determined as τT = 2.4 ‐ 2.8 μs. Fluorescence of tryptophan and tyrosine residues was unchanged upon light‐dark conversion, emphasizing the absence of significant conformational changes. Photochemistry was blocked upon cysteine C76 (C76S) mutation, causing a seven‐fold longer lifetime of the triplet state (τT = 16 ‐ 18.5 μs). Optoacoustic spectroscopy yielded the energy content of the triplet state. Interestingly, Xcc‐LOV did not undergo the volume contraction reported for other LOV domains within the observation time window, although the back‐conversion into the dark state was accompanied by a volume expansion. A radioactivity‐based enzyme function assay revealed a larger HK activity in the lit than in the dark state. The C76S mutant showed a still lower enzyme function, indicating the dark state activity being corrupted by a remaining portion of the long‐lived lit state. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-14T07:37:27.63621-05:0
      DOI: 10.1111/php.12493
  • International Intercomparison of Solar UVR Spectral Measurement Systems in
           Melbourne in 2013
    • Authors: Peter Gies; Rebecca Hooke, Richard McKenzie, John O'Hagan, Stuart Henderson, Andy Pearson, Marina Khazova, John Javorniczky, Kerryn King, Matt Tully, Michael Kotkamp, Bruce Forgan, Stephen Rhodes
      Abstract: Monitoring ambient solar UVR levels provides information on how much there is in both real time and historically. Quality assurance of ambient measurements of solar UVR is critical to ensuring accuracy and stability and this can be achieved by regular intercomparisons of spectral measurement systems with those of other organisations. In October and November of 2013 a solar UVR spectroradiometer from PHE was brought to Melbourne for a campaign of intercomparisons with a new Bentham spectrometer of ARPANSA and one at the Australian BOM, supported by NIWA from New Zealand. Given all three spectroradiometers have calibrations that are traceable to various national standards, the intercomparison provides a chance to determine measurement uncertainties and traceability that support UV measurement networks in Australia, New Zealand and the UK. UV Index measurements from all three systems were compared and ratios determined for clear sky conditions when the scans from each instrument were within 2 mins of each other. While wavelengths below 305 nm showed substantial differences between the PHE unit and the two other systems, overall the intercomparison results were encouraging, with mean differences in measured UV Index between the BOM/NIWA and those of PHE and ARPANSA of < 0.1% and 7.5% respectively. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-04T08:16:18.865238-05:
      DOI: 10.1111/php.12492
  • Photoreceptors in Chemotrophic Prokaryotes: The Case of Acinetobacter sps.
    • Authors: Clara B. Nudel; Klaas J. Hellingwerf
      Abstract: A comprehensive description of blue light using flavin (BLUF)‐ photosensory proteins, including preferred domain architectures and the molecular mechanism of their light‐activation and signal generation, among chemotrophic prokaryotes is presented. Light‐ regulated physiological responses in Acinetobacter sps from environmental and clinically relevant strains are discussed. The twitching motility response in A. baylyi sp. ADP1 and the joint involvement of three of the four putative BLUF‐domain containing proteins in this response, in this species, is presented as an example of remarkable photoreceptor redundancy. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-04T08:07:22.652105-05:
      DOI: 10.1111/php.12491
  • The Evolution and Functional Role of Flavin‐based Prokaryotic
    • Abstract: Flavin‐based photoreceptor proteins of the LOV (Light, Oxygen and Voltage) superfamily are ubiquitous and appear to be essential blue‐light sensing systems not only in plants, algae and fungi, but also in prokaryotes, where they are represented in more than 10% of known species. Despite their broad occurrence, only in few cases LOV proteins have been correlated to important phenomena such as bacterial infectivity, selective growth patterns or/and stress responses; nevertheless these few known roles are helping us understand the multiple ways by which prokaryotes can exploit these soluble blue‐light photoreceptors. Given the large number of sequences now deposited in databases, it becomes meaningful to define a signature for bona fide LOV domains, a procedure that facilitates identification of proteins with new properties and phylogenetic analysis. The latter clearly evidences that a class of LOV proteins from alpha‐proteobacteria is the closest prokaryotic relative of eukaryotic LOV domains, whereas cyanobacterial sequences cluster with the archaeal and the other bacterial LOV domains. Distance trees built for LOV domains suggest complex evolutionary patterns, possibly involving multiple horizontal gene transfer events. Based on available data, the in vivo relevance and evolution of prokaryotic LOV is discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-03T03:07:41.854469-05:
      DOI: 10.1111/php.12489
  • Phototherapy on the Treatment of Burning Mouth Syndrome: A Prospective
           Analysis of 20 Cases
    • Abstract: The aim of this study was to report the effect of laser phototherapy (LPT) on the treatment of Burning Mouth Syndrome (BMS). This prospective clinical study reports on preliminary outcomes of twenty volunteers diagnosed with BMS that undergone the conventional treatment prior to laser phototherapy. LPT consisted of one weekly session of LPT (660 nm), during ten weeks. The laser protocol consisted on the following parameters: 40 mW, 10 J/cm2, 0.4 J/point, irradiation time of 10 seconds. In all sessions the burning intensity was evaluated with a 10 cm Visual Analogue Scale (VAS). The burning intensity evaluation by VAS was performed immediately before and after each LPT session. Non‐parametric test of Wilcoxon was used for statistical analysis, considering a significance level of 5%. All volunteers reported reduced burning intensity in all sessions when compared to the previous one and reduction in VAS scores by up to 49% in the last clinical session when compared to the first session. When only the VAS baseline of the first session was compared with the consecutive sessions, there was a statistically significant reduction in VAS scores in almost all sessions. The LPT may be an alternative treatment for the relief of oral burning symptoms in patients with BMS. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-03T03:07:02.399658-05:
      DOI: 10.1111/php.12490
  • DNA Ligases I and III Support Nucleotide Excision Repair in DT40 Cells
           with Similar Efficiency
    • Abstract: In eukaryotic cells helix‐distorting DNA lesions like cyclobutane pyrimidine dimers (CPDs) and 6‐4 pyrimidine‐pyrimidone photoproducts (6‐4 PPs) are efficiently removed by nucleotide excision repair (NER). NER is a multistep process where in the end, subsequent to replication over the gap, the remaining nick is sealed by a DNA ligase. Lig1 has been implicated as the major DNA ligase in NER. Recently, Lig3 has been implicated as a component of a NER subpathway that operates in dividing cells, but which becomes particularly important in non‐dividing cells. Here, we use DT40 cells and powerful gene targeting approaches for generating DNA ligase mutants to examine the involvement and contribution of Lig1 and Lig3 in NER using cell survival measured by colony formation, and repair kinetics of CPD by immunofluorescence microscopy and immuno‐slot‐blotting. Our results demonstrate an impressive and previously undocumented potential of Lig3 to substitute for Lig1 in removing helix‐distorting DNA lesions by NER in proliferating cells. We show for the first time in a clean genetic background a functional redundancy in NER between Lig1 and Lig3, which appears to be cell cycle independent and which is likely to contribute to the stability of vertebrate genomes. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-01T09:51:02.781337-05:
      DOI: 10.1111/php.12487
  • Effects of Light and Salinity Stresses in Production of
    • Authors: Paulo Vale
      Abstract: Mycosporine‐like amino acids (MAAs) were analyzed in a Portuguese Gymnodinium catenatum strain when transferred to high salinity and high light conditions. Total MAA concentrations increased progressively between 30 and 36 psu, attaining at 36 psu 2.9‐fold the 30 psu treatment. When abruptly transferred to solar light in an outdoor shadowed location, MAA concentration increased steadily along the day for most compounds. After 8 hours, mycosporine‐glycine, palythene and M‐319 attained or surpassed 25‐fold their initial concentration, while M‐370 only attained 4‐fold concentration. When transferred from halogen to fluorescent light, polar MAAs such as shinorine and porphyra‐334, increased until day two and then declined, while M‐370 increase slowly, becoming the dominant compound from the profile after one week. These experiments put into evidence the relation of palythene with M‐319, which was further identified as its acid degradation product, palythine. Acid degradation of M‐370 originated M‐324, while M‐311 seems to be the precursor of M‐370. Under high salinity and high light conditions chain formation was altered towards shorter chains or solitary cells. This alteration can represent a morphological stress sign, which in the natural environment could affect average population speed during daily vertical migrations. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-01T09:50:37.213538-05:
      DOI: 10.1111/php.12488
  • A family of Potent Ru(II) Photosensitizers with Enhanced DNA
           Intercalation: Bimodal Photokillers
    • Authors: Eleftherios K. Pefkianakis; Theodossis A. Theodossiou, Dimitra K. Toubanaki, Evdokia Karagouni, Polycarpos Falaras, Kyriakos Papadopoulos, Georgios C. Vougioukalakis
      Abstract: A new family of Ru(II)‐based photosensitizers was synthesized and systematically characterized. The ligands employed to coordinate the ruthenium metal center were the commercially‐available 2,2’‐bipyridine and a pyridine‐quinoline hybrid bearing an anthracene moiety. The complexes obtained carry either PF6‐ or Cl‐ counterions. These counterions determine the complexes’ hydrophobic or hydrophilic character, respectively, therefore dictating their solubility in biologically related media. All photosensitizers exhibit characteristic, relatively strong and wide UV‐Vis absorption spectral profiles. Their high efficiency in generating cytotoxic singlet oxygen was established (up to ΦΔ~0.8). Moreover, the interaction of these photosensitizers with double‐stranded DNA was studied fluoro‐ and photo‐spectroscopically and their binding affinities were found to be of the order of 3 × 107 M‐1. All complexes are photocytotoxic to DU145 human prostate cancer cells. The highest light‐induced toxicity was conferred by the photosensitizers bearing Cl‐ counterions, probably due to the looser ionic “chaperoning” of Cl‐, in comparison to PF6‐, leading to higher cell internalization. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-28T06:26:31.164552-05:
      DOI: 10.1111/php.12485
  • Effect of 808 nm Diode Laser on Swimming Behavior, Food Vacuole Formation
           and Endogenous ATP Production of Paramecium primaurelia (Protozoa)
    • Authors: Andrea Amaroli; Silvia Ravera, Steven Parker, Isabella Panfoli, Alberico Benedicenti, Stefano Benedicenti
      Abstract: Photobiomodulation (PBM) has been used in clinical practice for more than 40 years. To clarify the mechanisms of action of PBM at cellular and organism levels, we investigated its effect on Paramecium primaurelia (Protozoa) irradiated by a 808 nm infrared diode laser with a flat‐top handpiece (1 W in CW). Our results lead to the conclusion that: 1) The 808 nm laser stimulates the P. primaurelia without a thermal effect. 2) The laser effect is demonstrated by an increase in swimming speed and in food vacuole formation. 3) The laser treatment affects endogenous adenosine triphosphate (ATP) production in a positive way. 4) The effects of irradiation dose suggest an optimum exposure time of 50 s (64 J/cm2 of fluence) to stimulate the Paramecium cells; irradiation of 25 s shows no effect or only mild effects and irradiation up to 100 s does not increase the effect observed with 50 s of treatment. 5) The increment of endogenous ATP concentration highlight the positive photobiomodulating effect of the 808 nm laser and the optimal irradiation conditions by the flat‐top handpiece. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-28T06:26:15.650208-05:
      DOI: 10.1111/php.12486
  • Melanopsins: localization and phototransduction in Xenopus laevis
    • Abstract: Xenopus laevis melanophores express two melanopsins, Opn4x and Opn4m. We identified Opn4x immunoreactivity throughout the melanophore cytoplasm and in the cell membrane. The strongest immunopositivity for Opn4m was observed in the nuclear region, and no labeling was seen in the cell membrane. This immunodistribution suggests Opn4x as the functional photopigment. In X. laevis melanophores, light triggers pigment dispersion and clock gene induction at blue wavelength, which maximally activates melanopsins. Although light stimulation activates phospholipase C and increases intracellular calcium and cGMP, this nucleotide does not participate in photo‐induced melanin dispersion. Nevertheless, the guanylyl cyclase activator YC‐1 stimulates Per1 expression, similar to blue‐light pulse, and the use of pharmacological inhibitors indicate the participation of the phosphoinositide cascade. Since cAMP levels does not change after blue light stimulation, the cAMP/PKA pathway most probably is not involved in blue light induction of Per in X. laevis melanophores. Given the localization of melanopsins and our pharmacological data, the light induced clock gene expression seems to be mediated by Opn4x through phosphoinositide cascade and rise in cGMP, thus leading to the reset of the biological clock in our model. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-25T00:53:36.80522-05:0
      DOI: 10.1111/php.12484
  • Photodynamic Action Mechanism Mediated by Zinc(II)
           in Candida albicans Cells
    • Authors: M. Albana Di Palma; M. Gabriela Alvarez, Edgardo N. Durantini
      Abstract: The photoreaction type I/type II pathways mediated by zinc(II) 2,9,16,23‐tetrakis[4‐(N‐methylpyridyloxy)]phthalocyanine (ZnPPc4+) was studied in Candida albicans cells. This photosensitizer was strongly bound to C. albicans cells at short times. After 30 min irradiation, 5 μM ZnPPc4+ produced ~5 log decrease of cell viability. Different probes were used to detect reactive oxygen species (ROS) in cell suspensions (~106 CFU/mL). Singlet molecular oxygen, O2(1Δg), was observed by the reaction with 9,10‐dimethylanthracene (DMA) and tetrasodium 2,2‐(anthracene‐9,10‐diyl)bis(methylmalonate) (ABMM), while the nitro blue tetrazolium (NBT) method was used to sense superoxide anion radical (O2.‐). Moreover, the effects produced by an anoxic atmosphere and cell suspensions in D2O, as well as the addition of sodium azide and mannitol as ROS trapping were evaluated in the PDI of C. albicans. These investigation indicates that O2(1Δg) is generated in the cells, although a minor extension other radical species can also be involved in the PDI of C. albicans mediated by ZnPPc4+. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-24T14:13:47.419518-05:
      DOI: 10.1111/php.12483
  • Impact of Substituents in Tumor‐Uptake and Fluorescence Imaging
           Ability of Near Infrared Cyanine‐like Dyes
    • Authors: Nayan J. Patel; Ethirajan Manivannan, Penny Joshi, Tymish J. Ohulchanskyy, Roger R. Nani, Martin J. Schnermann, Ravindra K. Pandey
      Abstract: This report presents a simple strategy to introduce various functionalities in a cyanine dye (bis‐indole‐N‐butylsulfonate‐polymethine bearing a fused cyclic chloro‐cyclohexene ring structure), and assess the impact of these substitutions in tumor uptake, retention and imaging. The results obtained from the SAR study demonstrate that certain structural features introduced in the cyanine dye moiety make a remarkable difference in tumor avidity. Among the compounds investigated, the symmetrical CDs containing an amino‐phenyl thioether group attached to a cyclohexene ring system and the two N‐butyl linkers with terminal sulfonate groups in benzoindole moieties exhibited excellent tumor imaging ability in BALB/c mice bearing Colon26 tumors. Compared to indocyanine green (ICG), approved by FDA as a blood pooling agent, which has also been investigated for the use in tumor‐imaging, the modified CD selected on the basis of SAR study produced enhanced uptake and longer retention in tumor(s). A facile approach reported herein for introducing a variety of functionalities in tumor‐avid CD provides an opportunity to create multi‐imaging modality agent(s). Using a combination of mass spectrometry and absorbance techniques, the photobleaching of one of the CDs was analyzed and significant regioselective photooxidation was observed. \ This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-24T10:01:15.777259-05:
      DOI: 10.1111/php.12482
  • Identification and Purification of the CPD Photolyase in Vibrio
           parahaemolyticus RIMD2210633
    • Authors: Zehong Su; Gaojian Lian, Kazuaki Mawatari, Ping Tang, Shuya He, Takaaki Shimohata, Yimou Wu, Weidong Yin, Akira Takahashi
      Abstract: Photoreactivation is an error‐free mechanism of DNA repair, utilized by prokaryotes and most eukaryotes and is catalyzed by specific enzymes called DNA photolyases. Photoreactivation has been reported in Vibrio parahaemolyticus WP28; however, information on photolyases in V. parahaemolyticus (V.p) strains has not been reported. The current study examined the photoreactivation in V. p RIMD2210633. The photolyase responsible for repairing cyclobutane pyrimidine dimer (CPD) in DNA was identified, and the corresponding gene was determined as VPA1471. The protein was overexpressed in Escherichia coli and was purified for functional assessment in vitro. The mRNA level and protein expression level of this gene increased after ultraviolet A (UVA) illumination following ultraviolet C (UVC) irradiation. In vitro experiments confirmed that the protein encoded by VPA1471 could reduce the quantity of CPD in DNA. We designated the corresponding gene and protein of VPA1471 phr and Phr, respectively, although the function of two other photolyase/cryptochrome family members, VPA0203 and VPA0204, remains unclear. UV (ultraviolet) irradiation experiments suggest that these two genes possess some photorepairing ability. Therefore, we hypothesize that VPA0203 and VPA0204 encode (6‐4) photolyase in V. parahaemolyticus RIMD2210633. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-23T03:05:42.322543-05:
      DOI: 10.1111/php.12481
  • Effectiveness of the Photoactive Dye Methylene Blue versus Caspofungin on
           the Candida parapsilosis Biofilm in vitro and ex vivo
    • Abstract: This research studied the effectiveness of the photoactive compound methylene blue (MB) activated with red LED light (576‐672 nm) compared to that of caspofungin (CAS) on 1 Candida albicans and 3 Candida parapsilosis strains. Results were evaluated in terms of SMIC50 for CAS or in PDI (photodynamic inactivation)‐SMIC50 for MB (minimal inhibitory concentration inhibiting sessile biofilm to 50% in comparison to the control without CAS or after irradiation in comparison to the control without MB). While all strains were susceptible to CAS in planktonic form, the SMIC50 was determined to be > 16 μg mL‐1 when CAS was added to a 24‐h biofilm. However, PDI‐MIC50s (1.67 mW cm‐2, fluence 15 J cm‐2) were 0.0075 ‐ 0.03 mmol L‐1. For biofilm, PDI‐SMIC50s were in the range from 0.7 to 1.35 mmol L‐1. An MB concentration of 1 mmol L‐1 prevented a biofilm being formed ex vivo on mouse tongues after irradiation regardless of the application time, in contrast to CAS, which was only effective at a concentration of 16 μg mL‐1 when it was added at beginning of biofilm formation. PDI seems to be a promising method for the prevention of microbial biofilms that do not respond significantly to conventional drugs. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-20T02:22:56.879934-05:
      DOI: 10.1111/php.12480
  • Reclamation of Water Polluted with Flubendiamide Residues by
           Photocatalytic Treatment with Semiconductor Oxides
    • Abstract: The photodegradation of flubendiamide (benzenedicarboxamide insecticide), a relatively new insecticide was investigated in aqueous suspensions of binary (ZnO and TiO2) and ternary (Zn2TiO4 and ZnTiO3) oxides under artificial light (300‐460 nm) irradiation. Photocatalytic experiments showed that the addition of semiconductors, especially ZnO and TiO2, in tandem with an electron acceptor (Na2S2O8) enhances the degradation rate of this compound in comparison with those carried out with catalyst alone and photolytic tests. The photocatalytical degradation of flubendiamide using ZnO/Na2S2O8 and TiO2/Na2S2O8 followed first‐order kinetics. In addition, desiodo‐flubendiamide was identified during the degradation of flubendiamide. Finally, application of these reaction systems in different waters (tap, leaching and watercourse) showed the validity of the treatments, which allowed the removal of flubendiamide residues in these drinking and environmental water samples. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-18T03:25:04.598461-05:
      DOI: 10.1111/php.12479
  • Comment to the paper: “Endogenous Retinoic Acid Required to Maintain
           the Epidermis Following Ultraviolet Light Exposure in SKH‐1 Hairless
           Mice” by Katherine L. Gressel et al., Photochemistry &
           Photobiology DOI: 10.1111/php.12441
    • Authors: Keith Fluegge
      Abstract: The authors of the study [1] conclude that disulfiram (DSF) “reduced RA synthesis in these mice to undetectable levels, as indicated by reduced β‐galactosidase expression.” This conclusion is drawn from pilot work wherein the drug was applied topically and reporter gene expression was investigated histologically. DSF is a strong thiol‐reactive compound and therefore is expected to inhibit aldehyde dehydrogenase (ALDH) and therefore reduce RA synthesis through oxidation of the enzyme's nucleophilic cysteine residue within its active site. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-15T02:41:32.827759-05:
      DOI: 10.1111/php.12476
  • Enhanced Self‐Cleaning Properties on Polyester Fabric Under
           Visible–Light Through Single Step Synthesis of Cuprous Oxide Doped
           Nano TiO2
    • Authors: Hamdam Gaminian; Majid Montazer
      Abstract: Nowadays, introducing self‐cleaning properties on various fabrics under day‐light irradiation for automotive and upholstery application is in a central point of research. This can be achieved by application of metal doped TiO2 nano particles on the textile fabrics. Here, alkali hydrolysis of polyester fabric has been carried out along with synthesis of Cu2O/TiO2 nanoparticles in a single‐step process by using sonochemical technique. CuSO4.5H2O was used as a source of copper in the presence of glucose as reducing and stabilizing agent. Moreover, central composite design based on response surface methodology (RSM) was used to determine the role of variables (CuSO4.5H2O, glucose and pH) and their effects on the self‐cleaning properties and weight of the fabric. The self‐cleaning property was investigated by degradation of Methylene Blue on the surface of the treated fabrics under daylight. Further, the tensile properties, colorimetric measurement and washing fastness of the treated fabric produced in the optimum conditions were investigated. The morphology of Cu2O/TiO2 nanoparticles was examined using X‐ray diffraction and field emission scanning electron microscopy (FESEM). The new polyester fabric obtained through in situ synthesis of Cu2O /TiO2 nanoparticles can be used as a desirable stable fabric with high tensile strength and visible‐light self‐cleaning properties. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-15T02:37:16.27906-05:0
      DOI: 10.1111/php.12478
  • Response to Mr. Fluegge's comment on our paper: “Endogenous Retinoic
           Acid Required to Maintain the Epidermis Following Ultraviolet Light
           Exposure in SKH‐1 Hairless Mice” by Katherine L. Gressel
           et al., Photochemistry & Photobiology DOI: 10.1111/php.12441
    • Authors: Helen B Everts
      Abstract: Mr. Fluegge argues that part of the effects of disulfiram that we observed were due to non‐specific inhibition of DNA methyltransferase activity leading to the restoration of retinoic acid receptor beta (Rarb) expression. We acknowledge that disulfiram may have impacted our results independent of its effects on retinoic acid (RA) synthesis, but our data do not support a role of methylated Rarb. Disulfiram did inhibit DNA methyltransferase in prostate cancer cells and restored Rarb expression (1).. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-15T02:34:08.747895-05:
      DOI: 10.1111/php.12477
  • Measuring the Physiologic Properties of Oral Lesions Receiving
           Fractionated Photodynamic Therapy
    • Abstract: Photodynamic therapy (PDT) can treat superficial, early‐stage disease with minimal damage to underlying tissues and without cumulative dose‐limiting toxicity. Treatment efficacy is affected by disease physiologic properties, but these properties are not routinely measured. We assessed diffuse reflectance spectroscopy (DRS) for the noninvasive, contact measurement of tissue hemoglobin oxygen saturation (StO2) and total hemoglobin concentration ([tHb]) in the pre‐malignant or superficial microinvasive oral lesions of patients treated with 5‐aminolevulinic acid (ALA)‐PDT. Patients were enrolled on a Phase 1 study of ALA‐PDT that evaluated fluences of 50, 100, 150 or 200 J/cm2 delivered at 100 mW/cm2. In order to test the feasibility of incorporating DRS measurements within the illumination period, studies were performed in patients who received fractionated (two‐part) illumination that included a dark interval of 90‐180 seconds. Using DRS, tissue oxygenation at different depths within the lesion could also be assessed. DRS could be performed concurrently with contact measurements of photosensitizer levels by fluorescence spectroscopy, but a separate noncontact fluorescence spectroscopy system provided continuous assessment of photobleaching during illumination to greater tissue depths. Results establish that the integration of DRS into PDT of early‐stage oral disease is feasible, and motivates further studies to evaluate its predictive and dosimetric value. This article is protected by copyright. All rights reserved.
      PubDate: 2015-06-02T10:21:24.889198-05:
      DOI: 10.1111/php.12475
  • Estimating the Diurnal Cycle and Daily Insolation of Ultraviolet and
           Photosynthetically Active Radiation at the Sea Surface
    • Authors: Victor S. Kuwahara; Satoru Taguchi
      Abstract: Accurate determination of the diurnal variability and daily insolation of surface (0+) and sub‐surface (0‐) irradiance are essential to estimate several physical, chemical and biological processes occurring at the surface layer of marine environments. Natural downwelling PAR and spectral UVR were examined on eight occasions at 0+ and 0‐ to refine empirical models, particularly in the UVR spectrum. The diurnal variability in UVR and PAR were wavelength dependent and were modelled by a sinusoidal equation. The best fit for PAR at 0+ and 0‐ was the sinusoid power of n = 2 and n = 2.5, respectively. In the UVR spectrum, sinusoids increased as wavelengths decreased ranging from n = 2 – 5. Higher n values in the UV‐B spectrum suggest sharper increase/decrease near sunrise and sunset hours, ultimately reducing the final value of daily insolation at specified wavelengths. Calculated daily insolation of UV‐B/(UV‐A + PAR) ratio suggests that photo‐inhibition from exposure to UV‐B occurs within a shorter biologically effective day length than PAR, and is high during summer and low during winter. These results suggest that biogeochemical calculations based on diurnal models of irradiance measurements would benefit from accurate solar noon references and wavelength specificity, particularly in the UVR spectrum. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-28T08:04:41.399508-05:
      DOI: 10.1111/php.12474
  • Effects of UV‐C and Vacuum‐UV TiO2 Advanced Oxidation
           Processes on the Acute Mortality of Microalgae
    • Authors: Eric McGivney; Magnus Carlsson, Jon Petter Gustafsson, Elena Gorokhova
      Abstract: Advanced oxidation processes/technologies (AOT) that combine a semiconductor, such as titanium dioxide (TiO2), with a UV source have been used to eliminate microorganisms in various water treatment applications. To facilitate the applicability of this technique, the gain in efficiency from the semiconductor compared to the UV source alone with respect to different target organisms requires evaluation. The primary objective of this study was to determine the effects of TiO2 and UV wavelength on a freshwater alga, Pseudokirchneriella subcapitata, and a marine alga, Tetraselmis suecica. For each species, dose‐response experiments were conducted to determine the median lethal dose (LC50) of the following treatments: UV‐light emitted with a peak of 254 nm, UV‐light emitted with a peak of 254 nm in the presence of TiO2, and UV‐light emitted with a peak of 254 nm and 185 nm in the presence of TiO2. In both species, the presence of TiO2 significantly increased mortality. Across all three treatments, P. subcapitata was more sensitive than T. suecica; moreover, the addition of the 185 nm wavelength significantly increased cell mortality in P. subcapitata but not in T. suecica. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-28T07:55:48.249739-05:
      DOI: 10.1111/php.12473
  • Photophysics and Rotational Dynamics of a Hydrophilic Molecule in a Room
           Temperature Ionic Liquid
    • Authors: Aninda Chatterjee; Banibrata Maity, Sayeed Ashique Ahmed, Debabrata Seth
      Abstract: We have studied the photophysics and rotational diffusion of hydrophilic solute 7‐(N, N'diethylamino)coumarin‐3‐carboxylic acid (7‐DCCA) in a room temperature ionic liquid methyltrioctylammonium bis(trifluoromethylsulfonyl) imide ([N1888][NTf2]). Comparison of activation energy of viscous flow and nonradiative decay shows that the photophysical properties of 7‐DCCA are not guided by the bulk viscosity of the medium but dependent on the specific solute solvent interaction and structural heterogeneity of the medium. The rotational relaxation behaviour of 7‐DCCA in [N1888][NTf2] shows significant deviation from the Stokes EinsteinDebye hydrodynamic model of rotational diffusion. This is indicative of the influence of specific solute solvent interaction on the rotational relaxation behaviour of 7‐DCCA. Comparison of activation energy of rotational relaxation with activation energy of viscous flow clearly reinforces our assumption that the structural heterogeneity of the medium and specific solute solvent interaction plays a dominant role on the rotational diffusion instead of bulk viscosity. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-28T07:52:06.382574-05:
      DOI: 10.1111/php.12472
  • The Synthesis and Photocatalytic Properties of TiO2 Nano‐Tube Array
           by Starch Modified Anodic Oxidation
    • Authors: Fengjun Zhang; Zijian Liu, Wei Lu, Cong Lyu, Chuan Lyu, Xiansheng Wang
      Abstract: In this study, the characterization and photocatalytic activity of TiO2 nanotube arrays prepared by anodization process with starch addition were investigated in detail. The results suggested that the optimum mass fraction of starch added in anodization process was 0.1 %, with which TiO2 nanotube arrays owning good tubular structure were synthesized. The tube length and average inner diameter of nanotubes were approximately 4 μm and 30 nm, respectively. Through the characterization of TiO2 nanotube arrays by energy dispersive spectrometer, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier Transform Infrared (FTIR) spectroscopy, it was found that the as‐prepared nanotubes possessed well uniformed and higher photo‐degradation responsive than the pure TiO2. Moreover, it was expected that the as‐prepared nanotubes exhibited good photocatalytic activity for the degradation of RhB under UV‐light irradiation, which could be ascribed to their good morphology, enhanced UV‐light absorption property and electron transmission ability during the photocatalytic reaction. In addition, the nanotubes was not significantly regenerated during the cycling runs experiment. Overall, this study could provide a principle method to synthesize TiO2 nanotube arrays with enhanced photocatalytic activity by anodization process with starch addition for environmental purification. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-23T09:26:45.39142-05:0
      DOI: 10.1111/php.12471
  • How Does Photoreceptor UVR8 Perceive a UV‐B Signal?
    • Authors: Xiaojing Yang; Sherwin Montano, Zhong Ren
      Abstract: UVR8 is the only known plant photoreceptor that mediates light responses to UV‐B (280‐315 nm) of the solar spectrum. UVR8 perceives a UV‐B signal via light‐induced dimer dissociation, which triggers a wide range of cellular responses involved in photo‐morphogenesis and photo‐protection. Two recent crystal structures of Arabidopsis thaliana UVR8 (AtUVR8) have revealed unusual clustering of UV‐B‐absorbing Trp pigments at the dimer interface and provided a structural framework for further mechanistic investigation. This review summarizes recent advances in spectroscopic, computational and crystallographic studies on UVR8 that are directed towards full understanding of UV‐B perception at the molecular level. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-21T08:43:57.446734-05:
      DOI: 10.1111/php.12470
  • Doping of Zinc Oxide with Selected First Row Transition Metals for
           Photocatalytic Applications
    • Abstract: ZnO doped with Cr, Mn, Fe, Co, Ni and Cu was prepared by homogeneous hydrolysis of sulphates with urea. The samples were annealed at various temperatures and characterized by X‐ray powder diffraction, UV/VIS reflectance spectroscopy, BET (Brunauer‐Emmet‐Teller) surface area and porosity measurements. The photocatalytic activity of the samples was evaluated by measuring the degradation of an organic dye Reactive Black 5. The morphology of the samples was determined by scanning electron microscopy and atomic‐force microscopy. For the Cu‐doped ZnO sample, EPR spectra were obtained. All samples annealed at 800°C contained hexagonal ZnO. In the VIS region, the best photocatalytic performance had the ZnO samples doped with Cr, Fe and Cu. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-21T07:03:09.87815-05:0
      DOI: 10.1111/php.12469
  • Kinetic Model of Photoautotrophic Growth of Chlorella sp Microalga,
           Isolated from the Setúbal Lagoon
    • Abstract: In this work a kinetic expression relating light availability in the culture medium with the rate of microalgal growth is obtained. This expression, which is valid for low illumination conditions, was derived from the reactions that take part in the light‐dependent stage of photosynthesis. The kinetic expression obtained is a function of the biomass concentration in the culture, as well as of the local volumetric rate of absorption of photons, and only includes two adjustable parameters. In order to determine the value of these parameters and to test the validity of the hypotheses made, autotrophic cultures of the Chlorella sp. strain were carried out in a modified BBM medium at three CO2 concentrations in the gas stream, namely 0.034%, 0.34% and 3.4%. Moreover, the local volumetric rate of photon absorption was predicted based on a physical model of the interaction of the radiant energy with the suspended biomass, together with a Monte Carlo simulation algorithm. The proposed intrinsic expression of the biomass growth rate, together with the Monte Carlo radiation field simulator, are key to scale up photobioreactors when operating under low irradiation conditions, independently of the configuration of the reactor and of its light source. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-21T07:02:09.036876-05:
      DOI: 10.1111/php.12468
  • The Effect of Surface Charge Saturation On Heat‐induced Aggregation
           of Firefly Luciferase
    • Authors: Jamileh Gharanlar; Saman Hosseinkhani, Reza H.Sajedi, Parichehr Yaghmaie
      Abstract: We present here the effect of firefly luciferase surface charge saturation and the presence of some additives on its thermal‐induced aggregation. Three mutants of firefly luciferase prepared by introduction of surface Arg residues named as 2R, 3R and 5R have two, three and five additional arginine residues substituted at their surface compared to native luciferase; respectively. Turbidimetric study of heat‐induced aggregation indicates that all three mutants were reproducibly aggregated at higher rates relative to wild type in spite of their higher thermostability. Amongst them, 2R had most evaluated propensity to heat‐induced aggregation. Therefore, the hydrophilization followed by appearing of more substituted arginine residues with positive charge on the firefly luciferase surface was not reduced its thermal aggregation. Nevertheless, at the same condition in the presence of charged amino acids, e.g., Arg, Lys and Glu, as well as a hydrophobic amino acid, e.g., Val, the heat‐induced aggregation of wild type and mutants of firefly luciferases was markedly decelerated than those in the absence of additives. On the basis of obtained results it seems, relinquishment of variety in charge of amino acid side chains, they via local interactions with proteins cause to decrease rate and extent of their thermal aggregation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-20T02:51:28.058383-05:
      DOI: 10.1111/php.12467
  • Green Light to Plant Responses to Pathogens: the Role of Chloroplast
           Light‐Dependent Signaling in Biotic Stress
    • Abstract: Light has a key impact on the outcome of biotic stress responses in plants by providing most of the energy and many signals for the deployment of defensive barriers. Within this context, chloroplasts are not only the major source of energy in the light; they also host biosynthetic pathways for the production of stress hormones and secondary metabolites, as well as reactive oxygen species and other signals which modulate nuclear gene expression and plant resistance to pathogens. Environmental, and in particular, light‐dependent regulation of immune responses may allow plants to anticipate and react more effectively to pathogen threats. As more information is gathered, increasingly complex models are developed to explain how light and ROS signaling could interact with endogenous defense pathways to elicit efficient protective responses against invading microorganisms. The emerging picture places chloroplasts in a key position of an intricate regulatory network which involves several other cellular compartments. This article reviews current knowledge on the extent and the main features of chloroplast contribution to plant defensive strategies against biotic stress. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-19T05:34:46.385104-05:
      DOI: 10.1111/php.12466
  • Phototherapeutic Effect of Low‐Level Laser on Thyroid Gland of Gamma
           Irradiated Rats
    • Authors: Nadia Morcos; Manar Omran, Hala Ghanem, Mahmoud Elahdal, Nashwa Kamel, Elbatoul Attia
      Abstract: One inescapable feature of life on the earth is exposure to ionizing radiation. The thyroid gland is one of the most sensitive organs to gamma‐radiation and endocrine disrupters. Low level laser therapy (LLLT) has been used to stimulate tissue repair, and reduce inflammation. The aim of this study was to gauge the value of using Helium‐Neon laser to repair the damaged tissues of thyroid gland after gamma‐irradiation. Albino rats were used in this study (144 rat), divided into control, gamma, laser, and gamma plus laser irradiated groups, each group was divided into 6 subgroups according to time of treatment (total 6 sessions). Rats were irradiated once with gamma radiation (6 Gy), and an external dose of laser [Wavelength 632.8 nm, 12 mW, CW, Illuminated area 5.73 cm2, 2.1 mW/cm2, 120 sec, 1.4 J, 0.252 J/cm2] twice weekly localized on thyroid region of the neck, for a total of six sessions. Animals were sacrificed after each session. Analysis included thyroid function, oxidative stress markers, liver function and blood picture. Results revealed improvement in thyroid function, liver function and antioxidant levels, and the blood cells count after LLLT. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-14T09:40:10.099993-05:
      DOI: 10.1111/php.12465
  • Origins of the Intermediate Spectral Form in M100 Mutants of Photoactive
           Yellow Protein
    • Authors: Anil Kumar; G. Andrew Woolley
      Abstract: Numerous single site mutants of photoactive yellow protein (PYP) from H. halophila and as well as PYP homologs from other species exhibit a shoulder on the short wavelength side of the absorbance maximum in their dark‐adapted states. The structural basis for the occurrence of this shoulder, called the “intermediate spectral form,” has only been investigated in detail for the Y42F mutation. Here we explore the structural basis for occurrence of the intermediate spectral form in a M121E derivative of a circularly permuted H. halophila PYP (M121E‐cPYP). The M121 site in M121E‐cPYP corresponds to the M100 site in wild‐type H. halophila PYP. High resolution NMR measurements with a salt‐tolerant cryoprobe enabled identification of those residues directly affected by increasing concentrations of ammonium chloride, a salt that greatly enhances the fraction of the intermediate spectra form. Residues in the surface loop containing the M121E (M100E) mutation were found to be affected by ammonium chloride as well as a discrete set of residues that link this surface loop to the buried hydroxyl group of the chromophore via a hydrogen bond network. Localized changes in the conformational dynamics of a surface loop can thereby produce structural rearrangements near the buried hydroxyl group chromophore while leaving the large majority of residues in the protein unaffected. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-06T09:44:31.508713-05:
      DOI: 10.1111/php.12464
  • Vibronic Structures in Absorption and Fluorescence Spectra of Firefly
           Oxyluciferin in Aqueous Solutions
    • Authors: Miyabi Hiyama; Yoshifumi Noguchi, Hidefumi Akiyama, Kenta Yamada, Nobuaki Koga
      Abstract: To elucidate the factors determining the spectral shapes and widths of the absorption and fluorescence spectra for keto and enol oxyluciferin and their conjugate bases in aqueous solutions, the intensities of vibronic transitions between their ground and first electronic excited states were calculated for the first time via estimation of the vibrational Franck–Condon factors. The major normal modes, overtones and combination tones in absorption and fluorescence spectra are similar for all species. The theoretical full widths at half maximum of absorption spectra are 0.4–0.7 eV and those for the fluorescence spectra are 0.4–0.5 eV, except for phenolate‐keto that exhibits exceptionally sharp peak widths due to the dominance of the 0–0’ or 0’–0 band. These spectral shapes and widths explain many relevant features of the experimentally observed spectra. This article is protected by copyright. All rights reserved.
      PubDate: 2015-05-06T09:43:23.105823-05:
      DOI: 10.1111/php.12463
  • Ultraviolet B (UVB) Inhibits Skin Wound Healing by Affecting Focal
           Adhesion Dynamics
    • Abstract: As the most important interface between human body and external environment, skin acts as an essential barrier preventing various environmental damages, among which DNA‐damaging UV radiation from the sun remains the major environmental risk factor causing various skin diseases. It has been well documented that wavelengths in the UVB radiation range (290‐320 nm) of the solar spectrum can be absorbed by skin and lead to cutaneous injury and various other deleterious effects. During process such as wound healing, the orchestrated movement of cells in a particular direction is essential and highly regulated, integrating signals controlling adhesion, polarity and the cytoskeleton. Cell adhesion and migration are modulated through both of actin and microtubule (MT) cytoskeletons. However, little was known about how UVB affects skin wound healing and migration of epidermal keratinocytes. Here, we demonstrate that UVB can delay the wound healing progress in vivo with a murine model of full thickness skin wound. In addition, UVB significantly inhibited keratinocyte motility by altering focal adhesion turnover and cytoskeletal dynamics. Our results provide new insights into the etiology of UVB exposure‐induced skin damages. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-28T07:46:40.747542-05:
      DOI: 10.1111/php.12462
  • Solar Ultraviolet Radiation Exposure of South African Marathon Runners
           During Competition Marathon Runs and Training Sessions: A Feasibility
    • Authors: Victoria Nurse; Caradee Y Wright, Martin Allen, Richard L McKenzie
      Abstract: Marathon runners spend considerable time outdoors training for and participating in marathons. Outdoor runners may experience high solar ultraviolet radiation (UVR) exposure. South Africa, where running is popular, experiences high ambient solar UVR levels that may be associated with adverse health effects. This feasibility study explores the use of personal dosimeters to determine solar UVR exposure patterns and possible related acute health risks of four marathon runners during marathons and training sessions in Cape Town and Pretoria. Runners running marathons that started early in the day, and that did not exceed 4 hours, yielded low total solar UVR exposure doses (mean 0.093 SED per exposure period run, median 0.088 SED, range 0.062 – 0.136 SED; average of 16.54% of ambient solar UVR). Training sessions run during early morning and late afternoon presented similar results. Several challenges hindered analysis including accounting for anatomical position of personal dosimeter and natural shade. To assess health risks, hazard quotients (HQs) were calculated using a hypothetical runner's schedule. Cumulative, annual solar UVR exposure‐calculated acute health risks were low (HQ = 0.024) for training sessions and moderate (HQ = 4.922) for marathon runs. While these data and calculations are based on 18 person‐days, one can measure marathon runners’ personal solar UVR exposure although several challenges must be overcome. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-27T04:39:33.359396-05:
      DOI: 10.1111/php.12461
  • Hybrid Membrane of Agarose and Lanthanide Coordination Polymer: a
           Selective and Sensitive Fe3+ Sensor
    • Abstract: A new hybrid membrane was prepared by a facile method, based on a highly luminescent lanthanide coordination polymer and agarose. The soft membrane was characterized by FT‐IR, PXRD, SEM and luminescence. It is found that the soft membrane is a highly selective and sensitive sensor, among 19 metal ion solutions of Fe3+, Mg2+, Li+, Ca2+, Zn2+, Cu2+, Ba2+, Mn2+, Ru3+, Cr3+, Ag+, Sr2+, Cd2+, Na+, Ni2+, Pb2+, Fe2+, Hg2+ and Ca2+, only Fe3+ quench the luminescence. The sensing results can be distinguished by naked eye in the daylight or by irradiation of a portable UV light at the scene. Mechanism study reveal the sensing is due to the decomposition of the coordination polymer 1 which induced by slow permeation of Fe3+. Further studies found anions of BO3‐, CO32‐, H2PO4‐, Br‐, Cl‐, ClO4‐, H2PO4‐, I‐, IO3‐ and NO3‐ will not quench the luminescence of the hybrid membrane, which imply that other anions in water would not disturb the detection result. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-19T23:02:10.060319-05:
      DOI: 10.1111/php.12460
  • Minimizing Concentration of Sodium Hypochlorite in Root Canal Irrigation
           by Combination of Ultrasonic Irrigation with Photodynamic Treatment
    • Authors: Yanhuang Wang; Suli Xiao, Dianfu Ma, Xiaojing Huang, Zhiyu Cai
      Abstract: Concentration of sodium hypochlorite (NaOCl) is positively correlated to its effectiveness in root canal disinfection but negatively correlated to its biocompatibility. The objective of this in vitro study was to compare the bactericidal effects among ultrasonic irrigation with different concentration of NaOCl alone or together with photodynamic treatment (PDT) against Enterococcus faecalis (E. faecalis) in infected root canals. One hundred and twenty bovine root canals contaminated with E. faecalis were randomly distributed into 12 groups treated with different disinfection methods: PDT, ultrasonic irrigation with NaOCl at different concentrations (0.5%, 1.0%, 2.0%, 2.5% and 5.25%), and ultrasonic irrigation with NaOCl at different concentrations plus PDT. Data of microorganism load were collected before and after disinfection and analyzed by one‐way ANOVA and LSD tests. Significantly enhanced antibacterial effects were noticed in groups treated by PDT plus 2.0% or 2.5% NaOCl irrigation (P < 0.05). No statistical differences existed in bactericidal efficacy among groups of PDT plus ultrasonic irrigation with 2.0%, 2.5% or 5.25% NaOCl, and ultrasonic irrigation with 5.25% NaOCl alone (P > 0.05). Our study confirmed the feasibility to reduce the concentration of NaOCl to a safer level while maintaining its antibacterial efficiency through synergistic effect of PDT with NaOCl ultrasonic irrigation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-19T22:56:53.517395-05:
      DOI: 10.1111/php.12459
  • An Optimized Firefly Luciferase Bioluminescent Assay for the Analysis of
           Free Fatty Acids
    • Abstract: A firefly luciferase (LUC)‐based bioluminescent assay for total free fatty acids (FFA) is presented. It is based on LUC's capability of converting FFA into fatty acyl‐adenylates with consumption of adenosine 5’‐triphosphate (ATP). Since ATP is a co‐substrate in LUC's bioluminescent reaction, together with firefly d‐luciferin (d‐LH2) and atmospheric oxygen (O2), any reduction in the assay's ATP content will lead to a decrease in the bioluminescent signal, which is proportional to the amount of FFA. Using FFA mixtures containing myristic (14:0), palmitic (16:0), stearic (18:0), oleic (18:1) and arachidonic acid (20:4) in ethanol, the assay was optimized through statistical experimental design methodology, namely fractional factorial (screening) and central composite (optimization) designs. The optimized method requires 2 μL of sample per tube in a final reaction volume of 50 μL. It is linear in the concentration range from 1 to 20 μM, with limits of detection (LOD) and quantitation (LOQ) of 1.3 and 4.5 μM, respectively. The method proved to be simple to perform, demands low reagent volumes, it is sensitive and robust and may be adapted to high‐throughput screening. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-16T07:56:38.018896-05:
      DOI: 10.1111/php.12458
  • Promotion of Pro‐Apoptotic Signals by Lysosomal Photodamage
    • Authors: David Kessel; John J. Reiners
      Abstract: We previously reported that low level lysosomal photodamage enhanced the efficacy of subsequent mitochondrial photodamage, resulting in a substantial promotion of apoptotic cell death. We now extend our analysis of the sequential PDT protocol to include two additional lysosomal‐targeting photosensitizers. These agents, because of enhanced permeability, are more potent than the agent (N‐aspartyl chlorin E6, NPe6) used in the initial study. Addition of the cell‐permeable cysteine protease inhibitor E‐64d and calcium chelator BAPTA‐AM almost completely suppressed sequential PDT‐induced loss of mitochondrial membrane potential, activation of procaspases‐3 and ‐7 and loss of colony formation. These inhibitors did not, however, suppress the pro‐apoptotic effect of a BH3 mimetic or mitochondrial photodamage. Knockdowns of ATG7 or ATG5, proteins normally associated with autophagy, suppressed photokilling induced by the sequential PDT protocol. These effects appear to be independent of the autophagic process since pharmacological inhibition of autophagy offered no such protection. Effects of ATG7 and ATG5 knockdown may reflect the role that ATG7 plays in regulating lysosome permeability, and the likelihood that a proteolytic fragment of ATG5 amplifies mitochondrial pro‐apoptotic processes. Our results suggest that low‐dose photodamage that sequentially targets lysosomes and mitochondria may offer significant advantages over the use of single photosensitizers. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-15T01:52:21.372731-05:
      DOI: 10.1111/php.12456
  • Light‐mediated DNA Repair Prevents UVB‐induced Cell Cycle
           Arrest in Embryos of the Crustacean Macrobrachium olfersi
    • Abstract: High levels of ultraviolet‐B (UVB) radiation can negatively affect aquatic animals. Macrobrachium olfersi is a prawn that lives in clear freshwaters and during the breeding season, females carry eggs in an external brood pouch. Therefore, we hypothesize that eggs are also exposed to environmental UVB radiation. The aim of this study was to investigate whether UVB radiation induces DNA damage and compromises cell‐cycle in embryos of M. olfersi. In laboratory, UVB irradiance (310−2) that embryos receive in the natural environment was simulated. After irradiation, embryos were kept under different light conditions in order to recognize the presence of cell repair. UVB radiation induces DNA damage, specifically thymine dimers. After 48h of UVB exposure, a significant decrease in the level of these dimers was observed in embryos kept under visible light while it remained constant in the dark. Moreover, under visible light and darkness, a decrease in proliferation was observed after 48h of irradiation. An increase in PCNA expression and decrease in p53 expression were observed after, respectively, 1h and 48h of exposure. Our results showed that UVB radiation disturbs the cell‐cycle and induces DNA damage in M. olfersi embryos. However, under visible light these embryos showed successful DNA repair. This article is protected by copyright. All rights reserved.
      PubDate: 2015-04-13T11:49:30.413911-05:
      DOI: 10.1111/php.12457
  • Effects of Silencing Heme Biosynthesis Enzymes on 5‐Aminolevulinic
           Acid‐mediated Protoporphyrin IX Fluorescence and Photodynamic
    • Authors: Xue Yang; Weihua Li, Pratheeba Palasuberniam, Kenneth A. Myers, Chenguang Wang, Bin Chen
      Abstract: Aminolevulinic acid (ALA)‐mediated protoporphyrin IX (PpIX) production is being explored for tumor fluorescence imaging and photodynamic therapy (PDT). As a prodrug, ALA is converted in heme biosynthesis pathway to PpIX with fluorescent and photosensitizing properties. To better understand the role of heme biosynthesis enzymes in ALA‐mediated PpIX fluorescence and PDT efficacy, we used lentiviral shRNA to silence the expression of porphobilinogen synthase (PBGS), porphobilinogen deaminase (PBGD) and ferrochelatase (FECH) in SkBr3 human breast cancer cells. PBGS and PBGD are the first two cytosolic enzymes involved in PpIX biosynthesis, and FECH is the enzyme responsible for converting PpIX to heme. PpIX fluorescence was examined by flow cytometry and confocal fluorescence microscopy. Cytotoxicity was assessed after ALA‐mediated PDT. Silencing PBGS or PBGD significantly reduced ALA‐stimulated PpIX fluorescence whereas silencing FECH elevated basal and ALA‐stimulated PpIX fluorescence. However, compared with vector control cells, the ratio of ALA‐stimulated fluorescence to basal fluorescence without ALA was significantly reduced in all knockdown cell lines. PBGS or PBGD knockdown cells exhibited significant resistance to ALA‐PDT, while increased sensitivity to ALA‐PDT was found in FECH knockdown cells. These results demonstrate the importance of PBGS, PBGD and FECH in ALA‐mediated PpIX fluorescence and PDT efficacy. This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-21T09:12:33.479197-05:
      DOI: 10.1111/php.12454
  • Photo– and chemical–reduction of copper onto
           anatase–type TiO2 nanoparticles with enhanced surface hydroxyl
           groups as efficient visible–light photocatalysts
    • Authors: Hamed Eskandarloo; Alireza Badiei, Mohammad A. Behnajady, Ghodsi Mohammadi Ziarani
      Abstract: In this study, the photocatalytic efficiency of anatase–type TiO2 nanoparticles synthesized using the sol–gel low temperature method, were enhanced by a combined process of copper reduction and surface hydroxyl groups enhancement. UV–light–assisted photo– and NaBH4–assisted chemical–reduction methods were used for deposition of copper onto TiO2. The surface hydroxyl groups of TiO2 were enhanced with the assistance of NaOH modification. The prepared catalysts were immobilized on glass plates and used as the fixed–bed systems for the removal of phenazopyridine as a model drug contaminant under visible–light irradiation. NaOH–modified Cu/TiO2 nanoparticles demonstrated higher photocatalytic efficiency than that of pure TiO2 due to the extending of the charge carriers lifetime and enhancement of the adsorption capacity of TiO2 toward phenazopyridine (PhP). The relationship of structure and performance of prepared nanoparticles has been established by using various techniques, such as XRD, XPS, TEM, EDX, XRF, TGA, DRS, and PL. The effects of preparation variables, including copper content, reducing agents rate (NaBH4 concentration and UV–light intensity), and NaOH concentration were investigated on the photocatalytic efficiency of NaOH–modified Cu/TiO2 nanoparticles. This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-21T09:08:37.910285-05:
      DOI: 10.1111/php.12455
  • Effects of enhanced UV‐B radiation on biochemical traits in
           postharvest flowers of medicinal chrysanthemum
    • Abstract: The paper reported UV‐B radiation effects on biochemical traits in postharvest flowers of chrysanthemum. The experiment included six levels of UV‐B radiation (UV0, 0 μW cm−2; UV50, 50 μW cm−2; UV200, 200 μW cm−2; UV400, 400 μW cm−2; UV600, 600 μW cm−2 and UV800, 800 μW cm−2). Enhanced UV‐B radiation significantly increased hydrogen peroxide content (except for UV50), but did not evidently affect malondialdehyde content in flowers. Chlorophyll b and total chlorophyll content were significantly increased by UV600 and UV800. UV400 and UV600 significantly increased anthocyanins, carotenoids and UV‐B absorbing compounds content, and the activities of phenylalanine ammonia lyase (PAL) and cinnamic acid‐4‐hydroxylase (C4H) over the control. 4‐coumarate CoA ligase (4CL) activity was significantly decreased by enhanced UV‐B radiation (except for UV50). The relationships between UV‐B radiation intensities and the activities of secondary metabolism enzymes were best described by a second‐order polynomial. The R2 values for UV‐B radiation intensities and the activities of PAL, C4H and 4CL were 0.8361, 0.5437 and 0.8025, respectively. The results indicated that enhanced UV‐B radiaiton could promote secondary metabolism processes in postharvest flowers, which might be beneficial for the accumulation of medically active ingredients in medicinal plants. The optimal UV‐B radiation intensities in the study were between UV400‐UV600. This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-17T00:27:18.202906-05:
      DOI: 10.1111/php.12450
  • Photodegradation of Hydrophobic Pyridineketoximes in Toluene and Heptane
    • Authors: Karolina Wieszczycka; Joanna Zembrzuska
      Abstract: The goal of the research was to study the reactivity of the hydrophobic 2‐ and 3‐pyridineketoximes under exposure to UV‐VIS light. The photodegradation was conducted in both toluene and heptane for 10 hours under atmosphere of argon. Ten‐hour irradiation experiments demonstrated that the pyridineketoximes underwent the facile E‐Z photoisomerisation, photo‐Beckmann rearrangement and, in the lesser extent, the photosubstitution to the pyridine ring. From LC‐MS and NMR analysis of the irradiated solutions it was found that the photosubstitution proceeded to give the corresponding 6‐substituted 2‐ or 3‐pyridylketoxime via the replacement of the ring hydrogen by the benzyl or heptyl group. The photo‐Beckmann rearrangement led to the formation of the corresponding amides, but also other products formed in the photo‐decomposition reaction This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-12T07:10:33.772255-05:
      DOI: 10.1111/php.12453
  • A Novel Microsensor for Measuring Angular Distribution of Radiative
    • Abstract: This article presents the design, construction, and characterization of a novel type of light probe for measuring the angular radiance distribution of light fields. The differential acceptance angle (DAA) probe can resolve the directionality of a light field in environments with steep light gradients, such as microbial mats, without the need to remove, re‐orient, and re‐insert the probe, a clear advantage over prior techniques. The probe consists of an inner irradiance sensor inside a concentric, moveable light absorbing sheath. The radiative intensity in a specific zenith direction can be calculated by comparing the irradiance onto the sensor at different acceptance angles. We used this probe to measure the angular radiance distribution of two sample light fields, and observed good agreement with a conventional radiance probe. The DAA probe will aid researchers in understanding light transfer physics in dense microbial communities and expedite validation of numerical radiative transfer models for these environments. This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-12T07:04:25.81225-05:0
      DOI: 10.1111/php.12452
  • Effects of PAR and UV radiation on the structural and functional integrity
           of phycocyanin, phycoerythrin and allophycocyanin isolated from the marine
           cyanobacterium Lyngbya sp. A09DM
    • Authors: Rajesh P Rastogi; Ravi Raghav Sonani, Datta Madamwar
      Abstract: An in vitro analysis of the effects of photosynthetically active and ultraviolet radiations was executed to assess the photostability of biologically relevant pigments phycocyanin (PC), phycoerythrin (PE) and allophycocyanin (APC) isolated from Lyngbya sp. A09DM. Ultraviolet (UV) irradiances significantly affected the integrity of PC, PE and APC; however, PAR showed least effect. UV radiation affected the bilin chromophores covalently attached to phycobiliproteins (PBPs). Almost complete elimination of the chromophore bands associated with α‐ and β‐subunit of PE and APC occurred after 4 h of UV‐B exposure. After 5 h of UV‐B exposure, the content of PC, PE and APC decreased by 51.65%, 96.8% and 96.53%, respectively. Contrary to PAR and UV‐A radiation, a severe decrease in fluorescence of all PBPs was observed under UV‐B irradiation. The fluorescence activity of extracted PBP was gradually inhibited immediately after 15‐30 min of UV‐B exposure. In comparison to the PC, the fluorescence properties of PE and APC were severely lost under UV‐B radiation. Moreover, the present study indicates that UV‐B radiation can damage the structural and functional integrity of phycobiliproteins leading to the loss of their ecological and biological functions This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-12T07:02:03.268454-05:
      DOI: 10.1111/php.12449
  • High Final Energy of Low ‐ Level Gallium Arsenide Laser Therapy
           Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen
    • Abstract: The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 Joules, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n=10); Injured (I, n=10) and Injured and laser treated (Injured/LLLT, n=10). The cryoinjury was induced in the central region of the Tibialis Anterior muscle (TA). The applications of the laser (904 nm, 50mW average power) were initiated 24 hours after injury, at energy density of 69 J/cm2 for 48 seconds, for five days, to two points of the lesion. Twenty‐four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF‐α, TGF‐β, MyoD and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (p
      PubDate: 2015-03-07T08:51:11.563966-05:
      DOI: 10.1111/php.12446
  • Biomodulation of Inflammatory Cytokines Related to Oral Mucositis by
           Low‐Level Laser Therapy
    • Abstract: This study evaluated the effects of LLLT on the expression of inflammatory cytokines related to the development of oral mucositis by gingival fibroblasts. Primary gingival fibroblasts were seeded on 24‐well plates (105 cells/well) for 24 hours. Fresh serum‐free culture medium (DMEM) was then added, and cells were placed in contact with LPS (Escherichia coli, 1 μg/mL), followed by LLLT irradiation (LaserTABLE ‐ InGaAsP diode prototype – 780 nm, 25 mW) delivering 0, 0.5, 1.5, or 3 J/cm². Cells without contact with LPS were also irradiated with the same energy densities. Gene expression of TNF‐α, IL‐1β, IL‐6, and IL‐8 was evaluated by Real‐Time PCR, and protein synthesis of these cytokines was determined by enzyme‐linked immunosorbent (ELISA) assay. Data were statistically analyzed by the Kruskal‐Wallis test, complemented by the Mann‐Whitney test (P < 0.05). LPS treatment increased the gene expression and protein synthesis of TNF‐α, IL‐6, and IL‐8, while the expression of IL‐1β was not affected. For LPS‐treated groups, LLLT promoted significant decreases in the expression of TNF‐α, IL‐6, and IL‐8 at 1.5 J/cm2 and 3 J/cm2. These results demonstrate that LLLT promoted a beneficial biomodulatory effect on the expression of inflammatory cytokines related to oral mucositis by human gingival fibroblasts. This article is protected by copyright. All rights reserved.
      PubDate: 2015-03-04T04:24:45.566994-05:
      DOI: 10.1111/php.12445
  • Photosensitizing Activity of Endogenous Eye Lens Chromophores: an Attempt
           to Unravel Their Contributions to Photo‐Aging and Cataract Disease
    • Abstract: UVA‐visible light has been proposed as a risk factor in the photo‐aging of the human eye lens, as well as in the etiology of cataract disease. There is accumulating evidence indicating that photosensitizing reactions mediated by endogenous chromophores, which are generated during human eye lens aging, can play an important role in the generation of these processes. These reactions can lead to protein impairment by inducing non‐enzymatic post‐translational modifications such as protein oxidation and crosslinking. Although numerous chromophores have been characterized as both bound to human eye lens proteins and as unbound low‐molecular‐mass compounds, their contribution to eye lens photoaging and cataract disease is not completely understood. In this article we discuss the photochemical contribution of UV‐filters derived from tryptophan catabolism and advanced glycation end products (AGEs) to human eye lens aging and cataract disease. We also discuss the recently described photosensitizing capacity of chromophores derived from newly discovered glucose and ascorbate degradation as a parallel pathway to their role in AGEs generation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-27T10:22:20.256761-05:
      DOI: 10.1111/php.12443
  • Endogenous Retinoic Acid Required to Maintain the Epidermis Following
           Ultraviolet Light Exposure in SKH‐1 Hairless Mice
    • Authors: Katherine L. Gressel; Jason F. Duncan, Tatiana M. Oberyszyn, Krista M. La Perle, Helen B. Everts
      Abstract: Ultraviolet light B (UVB) exposure induces cutaneous squamous cell carcinoma (cSCC), one of the most prevalent human cancers. Reoccurrence of cSCC in high‐risk patients is prevented by oral retinoids. But oral retinoid treatment causes significant side effects; and patients develop retinoid resistance. Exactly how retinoids prevent UVB‐induced cSCC is currently not well understood. Retinoid resistance blocks mechanistic studies in the leading mouse model of cSCC, the UVB exposed SKH‐1 hairless mouse. To begin to understand the role of retinoids in UVB‐induced cSCC we first examined the localization pattern of key retinoid metabolism proteins by immunohistochemistry 48 hours after UVB treatment of female SKH‐1 mice. We next inhibited retinoic acid (RA) synthesis immediately after UVB exposure. Acute UVB increased RA synthesis, signaling, and degradation proteins in the stratum granulosum. Some of these proteins changed their localization; while other proteins just increased in intensity. In contrast, acute UVB reduced the retinoid storage protein lectin:retinol acyltransferase (LRAT) in the epidermis. Inhibiting RA synthesis disrupted the epidermis and impaired differentiation. These data suggests that repair of the epidermis after acute UVB exposure requires endogenous RA synthesis. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-26T01:32:03.40306-05:0
      DOI: 10.1111/php.12441
  • Fluorescence properties of diphenylthiazolo[4,5‐b]pyrazines tuned by
           donor‐acceptor substituent effects
    • Authors: Tatsuki Nakagawa; Minoru Yamaji, Shojiro Maki, Haruki Niwa, Takashi Hirano
      Abstract: Fluorescence properties of 2,6‐ and 2,5‐diphenylthiazolo[4,5‐b]pyrazine (TPy) derivatives having an electron‐donating substituent (methoxy and dimethylamino) on the the 6‐ and 5‐phenyl groups were studied. It was found that 2,6‐diphenyl derivatives fluoresce more efficiently than 2,5‐diphenyl derivatives. Furthermore, a 2,6‐diphenyl derivative having an additional cyano group on the 2‐phenyl ring was an excellent fluorophore showing a wide solvatochromism with great fluorescence yields. Based on the obtained spectroscopic data and mechanistic explanations concerning the substituent effects on the fluorescence properties, useful information on designing new TPy fluorophores is provided. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-25T00:48:36.807819-05:
      DOI: 10.1111/php.12440
  • Actual Isothermal Effects of Water‐Filtered Infrared A
    • Abstract: In this study, the athermal effects of water‐filtered infrared A (wIRA)‐irradiation (780‐1400 nm) on human dermal fibroblasts were investigated. For this purpose, cells were exposed to wIRA‐irradiation (178 mW/cm2 for 1h), while a sophisticated experimental setup prevented warming of the samples exceeding 0.1 °C. The investigated parameters were the formation of reactive oxygen species (ROS), mitochondrial membrane potential and superoxide release, protein oxidation, proliferation rate, as well as intracellular Ca2+‐release in single cells, most of them quantified via fluorescence microscopy and fluorimetric techniques. The existence of actual athermal wIRA‐effects is still intensively discussed, since their detection requires a careful experimental setup and both efficient and powerful temperature regulation of the exposed samples. Here, we can definitively show that some of the supposed athermal wIRA‐effects may be rather artifacts, since wIRA did not reveal any impact on the above mentioned parameters ‐ as long as the temperature of the exposed cells was carefully maintained. Though, we were able to identify an athermal DNA‐protective wIRA‐effect, since the induced DNA‐damage (quantified via 8‐Oxo‐G‐formation) was significantly decreased after a subsequent UVB‐exposure. These results suggest that many of the supposed athermal wIRA‐effects can be induced by pure warming of the samples, independent from any wIRA‐irradiation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-24T03:42:44.028235-05:
      DOI: 10.1111/php.12439
  • Susceptibility of Ureaplasma urealyticum to methylene blue‐mediated
           photodynamic antimicrobial chemotherapy: an in vitro study
    • Authors: Tinglu Ye; Bancheng Chen, Bo Yu, Qili Zhong, Guoxing Huang, Xiaoping Hu, Wei Zhang
      Abstract: The aim of the present study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL−1) for 20 or 60min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100mW/cm2 for 8, 17, 34 or 68min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-17T08:28:12.130599-05:
      DOI: 10.1111/php.12438
  • Histopathological Analysis of UVB and IR Interaction in Rat Skin
    • Abstract: To determine the chronic skin effects caused by the interaction of infrared and ultraviolet B radiations, male Rattus norvegicus (Wistar) (2 months old) were exposed during 15 days to: infrared radiation (600 ‐ 1500 nm, with peak at 1000 nm, n = 12) for 30 minutes (1,080 J/cm²) (IR); to ultraviolet B radiation (peak emission at 313 nm, n = 9) for 90 minutes (55.08 J/cm²) (UVB); to infrared followed after 90 minutes by ultraviolet B (n = 6) (IRUVB) and to ultraviolet B followed after 90 minutes by infrared radiation (n = 9) (UVBIR). Skin samples were collected and histopathological analysis showed the presence of acanthosis, parakeratotic and orthokeratotic hyperkeratosis, intraepidermal pustules, keratin pearls, detachment of epidermis, collagen necrosis, inflammatory infiltrate, vasodilation, basal cell vacuolization and superficial dermis degeneration both in UVB and UVBIR treatments. IRUVB animals showed the same characteristics as above except for parakeratotic hyperkeratosis, keratin pearls and superficial dermis degeneration. To conclude, infrared radiation exposure after ultraviolet B irradiation increases skin damage without protecting the tissue, while infrared radiation exposure before ultraviolet B irradiation showed a protective effect against ultraviolet skin damage. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-16T01:01:32.123586-05:
      DOI: 10.1111/php.12435
  • Variability of solar radiation and CDOM in surface coastal waters of the
           Northwestern Mediterranean Sea
    • Abstract: Atmospheric and in‐water solar radiation, including UVR‐B, UVR‐A and PAR, as well as chromophoric dissolved organic matter absorption [aCDOM(λ)] in surface waters were monthly measured from November 2007 to December 2008 at a coastal station in the Northwestern Mediterranean Sea (Bay of Marseilles, France). Our results showed that the UVR‐B/UVR‐A ratio followed the same trend in the atmosphere and at 2 m depth in the water (p < 0.0001) with an increase (8 fold higher) during summer. The low diffuse attenuation coefficients for downward irradiance [Kd(λ)] of UVR‐B, UVR‐A and PAR indicated that the waters were highly transparent throughout the year. The relationships between aCDOM(λ) and Kd(λ) in this oligotrophic system suggested that CDOM contributed to UVR attenuation in the UVA domain, but also played a significant role in PAR attenuation. Mean UV doses received in the mixed layer depth were higher by a factor 1.4‐33 relative to doses received at fixed depths (5 and 10 m) in summer (stratified period), while the inverse pattern was found in winter (mixing period). This shows the importance of taking into account the vertical mixing in the evaluation of UVR effects on marine organisms. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-16T00:42:07.432593-05:
      DOI: 10.1111/php.12434
  • Human Hair as a Natural Sun Protection Agent: A Quantitative Study
    • Abstract: The rising incidence of skin cancers attributable to excessive sun exposure has become a major health concern worldwide. While numerous studies have analyzed the sun protective effect of sunscreens, clothing, and antioxidants, none to date have measured the photoprotective effect of hair, despite clinical evidence that individuals with balding or thinning hair are at greater risk of skin lesions that can progress to cancer, hence the recommendation to use hats or umbrellas. We analyzed the level of protection offered by hair according to hair density, thickness and color using the spectral transmittance and corrected for relative erythema effectiveness. Our results show that hair provides a barrier against both UVB and UVA radiation which is significantly increased with respect to the hair density, thickness and the presence of melanins. This is the first study to quantify sun protection factor offered by hair, namely hair ultraviolet protection factor (HUPF). We believe that hair should be recognized as an important natural sun barrier in the prevention of UV‐induced skin cancers. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-16T00:40:01.133958-05:
      DOI: 10.1111/php.12433
  • Interfacial engineering of CdO‐CdSe 3‐D
           micro‐architectures with in situ photopolymerized PEDOT for an
           enhanced photovoltaic performance
    • Abstract: In the present work, porous 3‐D CdO microstructured electrode obtained by pyrolysis of 3‐D CdCO3 microstructures is self‐sensitized with CdSe using an ion exchange reaction. After sensitization, an interfacial treatment of the CdO‐CdSe interface is performed by depositing a thin film of PEDOT using a photo‐induce polymerization route. The microstructured electrode before and after interfacial treatment is characterized using filed emission scanning microscope, energy dispersive X‐ray analyzer, contact angle measurement, UV‐Visible absorption spectrophotometer, and X‐ray photoelectron spectrometer. After constructing a liquid junction solar cell with a Pt counter electrode, the photovoltaic performance and interfacial charge transfer kinetics across the CdO‐CdSe interface before and after PEDOT treatment are investigated. The results exhibit an improved interfacial charge transfer resistance after the PEDOT treatment, which leads to enhance the short circuit current by 15.81 % and the power conversion efficiency by 19.82 %. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-09T02:44:31.089599-05:
      DOI: 10.1111/php.12429
  • Luciferin Regenerating Enzyme mediates firefly luciferase activation
           through direct effects of D‐cysteine on luciferase structure and
    • Authors: Roohullah Hemmati; Saman Hosseinkhani, Reza H. Sajedi, Taha Azad, Amin Tashakor, Nuredin Bakhtiari, Farangis Ataei
      Abstract: Luciferin regenerating enzyme (LRE) contributes to in vitro recycling of D‐luciferin. In this paper, reinvestigation of the luciferase‐ based LRE assay is reported. Here, using quick change site‐directed mutagenesis seven T‐LRE (Lampyris turkestanicus LRE) mutants were constructed and the most functional mutant of T‐LRE (T69R) was selected for this research and the effects of D‐ and L‐cysteine on T69R T‐LRE‐luciferase coupled assay are examined. Our results demonstrate that bioluminescent signal of T69R T‐LRE‐luciferase coupled assay increases and then reach equilibrium state in the presence of 5 mM D‐cysteine. In addition, results reveal that 5 mM D‐ and L‐cysteine in the absence of T69R T‐LRE cause a significant increase in bioluminescence intensity of luciferase over a long time as well as decrease in decay rate. Based on activity measurements, far‐UV CD analysis, ANS fluorescence and DLS (Dynamic light scattering) results, D‐cysteine increases the activity of luciferase due to weak redox potential, anti‐aggregatory effects, induction of changes in conformational structure and kinetics properties. In conclusion, in spite of previous reports on the effect of LRE on luciferase bioluminescent intensity, the majority of increase in luciferase light output and time‐course originate from the direct effects of D‐cysteine on structure and activity of firefly luciferase. This article is protected by copyright. All rights reserved.
      PubDate: 2015-02-09T02:44:15.11599-05:0
      DOI: 10.1111/php.12430
  • Salvianolic acid B protects normal human dermal fibroblasts against
           ultraviolet B irradiation‐induced photoaging through
           Mitogen‐activated protein kinase and activator protein‐1
    • Abstract: Exposure to ultraviolet (UV) light causes increased matrix metalloproteinase (MMP) activity and decreased collagen synthesis, leading to skin photoaging. Salvianolic acid B (SAB), a polyphenol, was extracted and purified from salvia miltiorrhiza. We assessed effects of SAB on UVB‐induced photoaging and investigated its molecular mechanism of action in UVB‐irradiated normal human dermal fibroblasts. Our results show that SAB significantly inhibited the UVB‐induced expression of metalloproteinases‐1 (MMP‐1) and interleukin‐6 (IL‐6) while promoting the production of type I procollagen and transforming growth factor β1 (TGF‐β1). Moreover, treatment with SAB in the range of 1–100 μg/mL significantly inhibited UVB‐induced extracellular signal‐regulated kinase (ERK), Jun N‐terminal kinase (JNK), and p38 phosphorylation, which resulted in decreasing UVB‐induced phosphorylation of c‐Fos and c‐Jun. These results indicate that SAB down‐regulates UV‐induced MMP‐1 expression by inhibiting Mitogen‐activated protein kinase (MAPK) signaling pathways and activator protein‐1 (AP‐1) activation. Our results suggest a potential use for SAB in skin photoprotection. This article is protected by copyright. All rights reserved.
      PubDate: 2015-01-28T00:23:26.530561-05:
      DOI: 10.1111/php.12427
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