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CHEMISTRY (594 journals)

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Journal Cover Photochemistry and Photobiology
  [SJR: 0.63]   [H-I: 106]   [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  [1589 journals]
  • LED Phototherapy with Gelatin Sponge Promotes Wound Healing in Mice
    • Authors: Heng Zhang; Shupeng Liu, Xiangfei Yang, Na Chen, Fufei Pang, Zhenyi Chen, Tingyun Wang, Jianshe Zhou, Fuji Ren, Xiaoyin Xu, Taihao Li
      Abstract: Tiny but highly efficient, a light-emitting diode (LED) can power a therapy device, such as a phototherapy device, and, at the same time, decrease the device's size requirements. In this study, a LED phototherapy device was designed to investigate the possible impact on wound healing using a mouse model and a cell line exposed to red and blue light. To enhance wound phototherapy, a gelatin sponge was fabricated. Results showed that the red and blue lights promoted cell growth and wound healing, while the blue light with a gelatin sponge protected the wound from infection in the early stages of wound healing. The LED phototherapy device combined with the gelatin sponge, therefore, has potential significance in clinical application for wound healing.A LED phototherapy device was designed to detect the possible effects for wound healing using a mouse model and a cell line exposed to red and blue light. To enhance the wound phototherapy, a gelatin sponge was fabricated and applied to the wound healing. Results showed that the red and blue light promoted cell growth and wound healing, while the blue light with a gelatin sponge protected the wound from infection in the early stages of wound healing. The LED phototherapy device combined with the gelatin sponge, therefore, has potential significance in clinical application for wound healing.
      PubDate: 2017-12-01T03:12:02.346459-05:
      DOI: 10.1111/php.12816
       
  • On the Validity of Beer-Lambert Law and its Significance for Sunscreens
    • Authors: Bernd Herzog; Amélie Schultheiss, Jochen Giesinger
      Abstract: The sun protection factor (SPF) is the most important quantity to characterize the performance of sunscreens. As the standard method for its determination is based on clinical trials involving irradiation of human volunteers, calculations of sunscreen performance have become quite popular in order to reduce the number of in vivo studies. Such simulations imply the calculation of UV-transmittance of the sunscreen film using the amounts and spectroscopic properties of the UV-absorbers employed, and presuppose the validity of the Beer-Lambert law. As sunscreen films on human skin can contain considerable concentrations of UV-absorbers, it is questioned whether the Beer-Lambert law is still valid for these systems. The results of this work show, that the validity of the Beer-Lambert law is still given at the high concentrations at which of UV-absorbers occur in sunscreen films on human skin.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-23T23:11:02.420904-05:
      DOI: 10.1111/php.12861
       
  • Antimicrobial Photodynamic Therapy Associated with Conventional Endodontic
           Treatment: A Clinical and Molecular Microbiological Study
    • Authors: Caroline C. da Silva; Sérgio P. Chaves Júnior, Gabriela L. D. Pereira, Karla B. F. C. da Fontes, Lívia A. A. Antunes, Helvécio C. C. Póvoa, Leonardo S. Antunes, Natalia L. P. Póvoa Iorio
      Abstract: This study evaluated antimicrobial photodynamic therapy (aPDT) as an adjunct to endodontic treatment. Ten uniradicular teeth (control group (CG)= 4 (2 and test group (TG)= 6) with primary endodontic infections, from both genders, between 17 and 65 years old, were analyzed. Microbiological samples were collected before and after chemical-mechanical instrumentation (CMI), after aPDT (for the TG), and after the removal of the temporary restorations (second session). In TG, the aPDT was performed with 100 μg/mL methylene blue and irradiated with low power laser (InGaAIP, 660 nm; 100 mW; 40 sec) with a fiber-coupled optical laser. Another irradiation (3 J; 30 sec; spot size of 3 mm2) was performed in the gingiva close to the apical foramen. The PCR was performed, after previous whole-genome amplification, for Enterococcus faecalis, Candida genus and Bacteria domain. For TG, a positive tooth for Candida spp. before of the CMI presented negative results in subsequent samples. Additionally, E. faecalis species was present in four samples before CMI, two after CMI, in one after the aPDT and was not detected at the second session. aPDT may be an effective adjunct therapy, resulting in a reduction (p=0.0286) of the incidence of E. faecalis before root canal obturation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T13:15:25.776924-05:
      DOI: 10.1111/php.12869
       
  • PhotochemCAD 3: Diverse Modules for Photophysical Calculations with
           Multiple Spectral Databases
    • Authors: Masahiko Taniguchi; Hai Du, Jonathan S. Lindsey
      Abstract: The PhotochemCAD program, developed over 30 years, is described comprehensively with focus on features of the most recent version (PhotochemCAD 3). The program is equipped with a streamlined user interface and provisions for handling multiple spectral databases. Eight modules enable calculations to be performed on the basis of the spectra in the databases. The calculational modules provide results concerning properties of individual compounds (oscillator strength, transition dipole moment, natural radiative lifetime), interactions of multiple compounds (Förster energy transfer, Dexter energy transfer, analysis of energy transfer among an array of chromophores), and composition of mixtures (multicomponent analysis). Synthetic spectra (blackbody radiator, Gaussian and Lorentzian curves, and delta functions) also can be generated. For comparison and calculation, synthetic and experimental spectra can be shifted along both coordinate axes and combined by addition, subtraction, and use of multiplicative factors. The core databases (described in the companion paper) have been expanded to 339 compounds for which absorption spectra (including molar absorption coefficient, ε), fluorescence spectra (including fluorescence quantum yield, Φf) and references to the primary literature have been included where available (551 spectra altogether). A database of 31 solar spectra also is included. Each calculational module is described along with illustrative examples.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T13:15:23.661903-05:
      DOI: 10.1111/php.12862
       
  • Database of Absorption and Fluorescence Spectra of>300 Common Compounds
           for use in PhotochemCAD
    • Authors: Masahiko Taniguchi; Jonathan S. Lindsey
      Abstract: The design of new molecules for photochemical studies typically requires knowledge of spectral features of pertinent chromophores beginning with the absorption spectrum (λabs) and accompanying molar absorption coefficient (ε, M−1cm−1) and often extending to the fluorescence spectrum (λem) and fluorescence quantum yield (Φf), where the fluorescence properties may be of direct relevance or useful as proxies to gain insight into the nature of the first excited singlet state. PhotochemCAD databases, developed over a period of 30 years, are described here. The previous databases for 150 compounds have been expanded to encompass 339 compounds for which absorption spectra (including ε values), fluorescence spectra (including Φf values) and references to the primary literature have been included where available (551 spectra altogether). The compounds exhibit spectra in the ultraviolet, visible, and/or near-infrared spectral regions. The compound classes and number of members include acridines (21), aromatic hydrocarbons (41), arylmethane dyes (11), azo dyes (18), biomolecules (18), chlorins/bacteriochlorins (16), coumarins (14), cyanine dyes (19), dipyrrins (7), heterocycles (26), miscellaneous dyes (13), oligophenylenes (13), oligopyrroles (6), perylenes (5), phthalocyanines (11), polycyclic aromatic hydrocarbons (16), polyenes/polyynes (10), porphyrins (34), quinones (24), and xanthenes (15). A database of 31 solar spectra also is included.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T13:00:23.09787-05:0
      DOI: 10.1111/php.12860
       
  • Suppression of UVB-mediated Matrix Metalloproteinase Generation by Sorbus
           commixta Twig Extract in Human Dermal Fibroblasts
    • Authors: Song Hua Xuan; Young Min Park, So Hyun Park, Hyo Jin Jeong, Soo Nam Park
      Abstract: Sorbus commixta is a traditional oriental medicinal plant that grows in East Asian countries such as Korea, Japan, and China. The twig of S. commixta has been considered valuable for centuries to treat diseases including asthma, cough, and other bronchial disorders. However, the effect of S. commixta twig extract on human skin has not been investigated well. The present study aimed at assessing the anti-photoaging effect of S. commixta twig ethanol extract (STE) on ultraviolet B (UVB)-induced matrix metalloproteinase (MMP) levels and its underlying mechanism in human dermal fibroblasts. In this study, we found that STE (12.5–50 μg/mL) treatment significantly inhibited UVB-induced MMP-1, MMP-2, and MMP-3 expression, concomitant with a downregulation of intracellular ROS generation. These effects might be associated with a STE-induced inhibition of the mitogen-activated protein kinase (MAPK) pathway. Furthermore, STE also downregulated UVB-induced c-Fos expression in a concentration dependent manner, but had no inhibitory effect on c-Jun phosphorylation. Taken together, these results indicate that STE may be an anti-photoaging agent, and that its effect may occur via its inhibition of MMPs expression and MAPK pathway activation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T04:00:30.74712-05:0
      DOI: 10.1111/php.12868
       
  • Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation
    • Authors: Michael R. Hamblin
      Abstract: Photobiomodulation (PBM) involves the use of red or near-infrared light at low power densities to produce a beneficial effect on cells or tissues. PBM therapy is used to reduce pain, inflammation, edema, and to regenerate damaged tissues such as wounds, bones and tendons. The primary site of light absorption in mammalian cells has been identified as the mitochondria, and more specifically, cytochrome c oxidase (CCO). It is hypothesized that inhibitory nitric oxide can be dissociated from CCO thus restoring electron transport and increasing mitochondrial membrane potential. Another mechanism involves activation of light or heat-gated ion channels. This review will cover the redox signaling that occurs in PBM and examine the difference between healthy and stressed cells, where PBM can have apparently opposite effects. PBM has a marked effect on stem cells, and this is proposed to operate via mitochondrial redox signaling. PBM can act as a pre-conditioning regimen, and can interact with exercise on muscles.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T03:56:17.53411-05:0
      DOI: 10.1111/php.12864
       
  • Nanoflower-like Yttrium-doped ZnO Photocatalyst for the Degradation of
           Methylene Blue Dye
    • Authors: Hemalatha Parangusan; Deepalekshmi Ponnamma, Mariam Al Ali Al-Maadeed, Alagar Marimuthu
      Abstract: Pure ZnO and Yttrium doped (Y-doped) ZnO at various mol% with flower-like nanostructures are synthesized by a microwave-assisted sol-gel method, followed by investigating the morphologies, crystal structures, optical properties and photocatalytic performances. While the phase formations are detected by X-ray diffraction technique, both scanning and transmission electron microscopy images clearly depict the flower-like morphology of ZnO and Y-doped ZnO samples. Formation of flower petals are from the nanoparticles that grew and connected by orientation attachment process. The flower-like architecture is addressed in terms of an Ostwald ripening mechanism. The UV-Vis absorption studies show enhanced absorption for the Y-doped ZnO whereas the photoluminescence spectra confirm the significance of sample defects in the photocatalytic degradation of organic pollutants. Effects of various experimental parameters such as the amount of photocatalysts, dye concentration and dopant concentration on the dye degradation are also optimized.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T02:50:21.065634-05:
      DOI: 10.1111/php.12867
       
  • Impact of Ultraviolet Radiation on Expression of Transforming Growth
           Factor-beta, Smad2, Metalloproteinases, Cathepsin K and Progerin
    • Authors: Magdalena Ciążyńska; Igor A. Bednarski, Karolina Wódz, Joanna Narbutt, Michał Sobjanek, Anna Woźniacka, Aleksandra Lesiak
      Abstract: Ultraviolet radiation (UVR) is one of the most important environmental factors involved in photoaging. Exposure to UVR leads to dysregulation of expression of cell-cycle-related proteins which play key role in skin photodegradation that pretends to develop carcinogenesis. This study examines the role of various UVB doses on the expression of transforming growth factor beta (TGF-β), Smad2, cathepsin K, progerin and matrix metalloproteinases (MMPs)-1,-3,-8,-9. A group consisting of 63 healthy individuals underwent one of the following treatments: 1) whole-body exposed to UVB irradiation on each of 10 consecutive days with 0.7 MED, or 2) whole-body irradiation as described followed by a single erythemal UVB dose on a small body area, or 3) irradiated only with a single erythemal UVB dose on small body area, or 4) were not irradiated at all (control group). When we compared all irradiated groups to the control group there was significantly higher expression of TGF-β, MMP-1,-3,-9, and cathepsin K proteins evaluated by western blot method. The results suggest the role of UVB in impairment of proteins expression that is involved in cell cycle's regulation. Changes of the proteins expression involved by acute and chronic UVR confirms its essential role in skin photodestruction. Moreover, obtained result indicates the tendency to occurrence of photoadaptation phenomenon.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T02:41:31.00211-05:0
      DOI: 10.1111/php.12866
       
  • Analysis of Erythemal UVB Dose Received Inside a Car in Valencia, Spain
    • Authors: Gonzalo Gurrea Ysasi; Vicente Blanca Giménez, Juan Carlos Moreno, MªAntonia Serrano
      Abstract: Continuous exposures to ultraviolet radiation can lead to harmful effects on human skin. Professional drivers may spend more than 8 hours per day inside a vehicle. This paper describes an analysis of the UVER (erythemal ultraviolet radiation) received by a driver and passenger inside a vehicle. A 3-door Peugeot 206 was used for the study. VioSpor Blue Line dosimeters (with a response profile close to that of human skin) were used to measure the erythematic dose of UV radiation (able to produce erythema on human skin). Four dosimeters were placed in the driver's position and another four in the passenger's position. Daily irradiance was analyzed for a day in April using PMA radiometers. The measurements were obtained on relatively clear days from February to December 2009 between 9:30 AM and 3 PM. Additionally, a prediction was made of the time required to produce an erythema on the driver's skin. UVER exposure, in some of the driver's positions, exceeds the Exposure Limits given by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Skin protection measures should be taken into account by professional drivers to prevent the harmful effects of UVER radiation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T02:40:11.702993-05:
      DOI: 10.1111/php.12865
       
  • Differential Perturbation of the Protrotropic Equilibrium of a Biological
           Photosensitizer within Bile Salt Aggregates of Varying Hydrophobicity: A
           Fluorimetric Investigation
    • Authors: Riya Sett; Nikhil Guchhait
      Abstract: The present work reveals the binding interactions of a credible cancer cell photosensitizer, harmane (HM) with some selected bile salt aggregates of dissimilar hydrophobicity viz. sodium deoxycholate (NaDC), sodium cholate (NaC) and sodium taurocholate (NaTC). The explicit variation of the prototropic equilibrium of the photosensitizer both in the ground and excited state has been utilized to scrutinize the interaction phenomena. Differential modulation in the prototropic equilibrium of HM in the aforesaid aggregates has been explained on the basis of the structural dissimilarities of the bile-salt monomers. The contrived hydrophobic surroundings provided by the aggregates have been reflected on the spectroscopic results; especially in the time-resolved fluorescence and the rotational dynamical behavior of the molecule of interest. Slow solvent reorientation time with regard to the lifetime of HM proliferated by the Red Edge Effect in two specific bile-salts namely NaC and NaTC; whereas its absence in NaDC aggregates has also been elucidated on the basis of accessibility of the solvent molecules within the aggregates.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T01:40:35.321401-05:
      DOI: 10.1111/php.12863
       
  • Theoretical Study on the Substituent Effect on the Excited-State Proton
           Transfer in the 7-Azaindole-Water Derivatives
    • Authors: Jiacheng Yi; Hua Fang
      Abstract: The first excited-state proton transfer (ESPT) in 7AI-H2O complex and its derivatives, in which the hydrogen atom at the C2 position in pyrrole ring was replaced by halogen atom X (X = F, Cl, Br), were studied at the TD-M06-2X/6-31 + G(d, p) level. The double proton transfer took place in a concerted but asynchronous protolysis pathway. The vibrational-mode selectivity of excited-state double proton transfer in the model system was confirmed. The specific vibrational-mode could shorten the reaction path and accelerate the reaction rate. The substituent effects on the excited-state proton transfer process were discussed. When the H atom at C2 position in 7AI-H2O complex was replaced by halogen atom, some geometrical parameters changed obviously, the barrier height of ESDPT reduced, and the asynchronicity of proton transfer enlarged. The above changes correlated with the Pauling electronegativity of halogen atom.The distance between two neighboring heavy atoms such as N1-O11 (R1) and O11-N8 (R2) distances played an important role in the proton transfer reaction. The sum of the N1-O11 and O11-N8 distances in the reactant of 2RAI-H2O (R = H, F, Cl, Br) complexes is in the range of 5.538 ~ 5.573 Å and changes along with the substituent group at C2 position in the pyrrole ring. The ESDPT barrier height and the sum of the N1-O11 and O11-N8 distances have a good correlation.
      PubDate: 2017-11-17T05:50:57.143117-05:
      DOI: 10.1111/php.12839
       
  • LncRNA RP11-670E13.6 Regulates Cell Cycle Progression in UVB Damaged Human
           Dermal Fibroblasts
    • Authors: Mengna Li; Li Li, Xiaofeng Zhang, Yan Yan, Baoxi Wang
      Abstract: Long noncoding RNAs (lncRNAs) have gained extensive attention in recent years, however, their effects on ultraviolet (UV) radiation-induced skin photodamage remain to be elucidated. In this study, we performed high-throughput RNA sequencing and comprehensive bioinformatics analyses to characterize the transcriptome profiles including lncRNAs and mRNAs in UVB-irradiated primary human dermal fibroblasts (HDFs) and to explore the roles of lncRNAs in photoaging. Quantitative reverse transcription-polymerase chain reaction amplification was performed to verify the differentially expressed genes. We subsequently found that knocking down of RP11-670E13.6, an upregulated lncRNA in UVB-irradiated HDFs, promoted a robust senescence phenotype, including increased numbers of the numbers of senescence-associated β-galactosidase-positive cells, decreased cell proliferation, accumulation of cells in G0/G1 phase, and a characteristic gene expression signature of senescent cells. In addition, western blot analysis showed that knocking down of RP11-670E13.6 activated the p16-pRB senescence pathway independent of the p53-p21 pathway. Therefore, we propose that RP11-670E13.6 may delay cellular senescence in UVB damaged HDFs through the p16-pRB pathway.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-16T03:26:42.650942-05:
      DOI: 10.1111/php.12858
       
  • Extracellular Matrix Containing in vitro Three-dimensional Tumour Models
           in Photodynamic Therapy-related Research
    • Authors: Beata Čunderlíková
      Abstract: Three-dimensional (3D) tumour models have been intensively evaluated for their use in cancer research and there is a strong rationale behind using 3D cell cultures in photodynamic therapy (PDT)-related experimentation. In this contribution, it is explained why 3D cell cultures containing extracellular matrix (ECM) are preferred for this purpose. Results of experimental studies utilizing ECM-containing 3D cellular models in PDT research are summarized. Finally, design of in vitro 3D models that would provide clinically relevant information is discussed.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-16T03:25:23.629924-05:
      DOI: 10.1111/php.12859
       
  • Cell Death Pathways Associated with Photodynamic Therapy: an Update
    • Authors: David Kessel; Nancy L. Oleinick
      Abstract: Photodynamic therapy (PDT) has the potential to make a significant impact on cancer treatment. PDT can sensitize malignant tissues to light, leading to a highly selective effect if an appropriate light dose can be delivered. Variations in light distribution and drug delivery, along with impaired efficacy in hypoxic regions, can reduce the overall tumor response. There is also evidence that malignant cells surviving PDT may become more aggressive than the initial tumor population. Promotion of more effective direct tumor eradication is therefore an important goal. While a list of properties for the ‘ideal’ photosensitizing agent often includes formulation, pharmacologic and photophysical elements, we propose that sub-cellular targeting is also an important consideration. Perspectives relating to optimizing PDT efficacy are offered here. These relate to death pathways initiated by photodamage to particular sub-cellular organelles.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-16T03:20:21.266904-05:
      DOI: 10.1111/php.12857
       
  • Deactivation and Regeneration of NaTaO3 Photocatalyst in Co-operating
           Dehydrogenation Coupling of Isopropanol and Hydrogenation Coupling of
           Acetone Reaction System
    • Authors: Baoyue Cao; Yan Yu, Shan Xu, Xiangting Wang, Li Zhang, Zhijian Wang, Shumin Wang, Guochun Zhang
      Abstract: Photocatalyst activity is influenced by many factors, such as adsorption of by-products, runoff of surface hydroxyl groups, and carriers. In this study, a simple and efficient photocatalyst regeneration method was developed. Results indicated that NaTaO3 photocatalyst lost its photo-activity after three cycles of reaction that involves coupling of isopropanol and hydrogenation coupling of acetone reaction system. Runoff of Na on the surface was the main reason for the deactivation of NaTaO3 photocatalyst. After hydrothermal treatment of the deactivated NaTaO3 with 10 M NaOH at 180 °C for 12 h, its photocatalytic activity was restored to the original level. The photocatalytic activity remained stable even after 10 cyclesThis article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T08:20:30.931139-05:
      DOI: 10.1111/php.12856
       
  • Effects of N-Glycosylation Deletions on Cypridina Luciferase Activity
    • Authors: Rie Yasuno; Yasuo Mitani, Yoshihiro Ohmiya
      Abstract: Cypridina luciferase (Cluc), a secreted luminescent protein identified from Cypridina noctiluca, has two N-glycosylation sites. In this study, we evaluated the effects of N-glycosylation on Cluc properties by creating site-directed mutagenic modifications at the consensus sequence for N-glycosylation (Asn-X-Ser/Thr). Eight variants consisting of four single- and double-residue mutants each were characterized. The producibility and relative specific activity were apparently reduced in mutant Cluc although the thermostability and secretion efficiency were not affected. These results suggested that N-glycosylation modifications and the proper amino acid sequence of the N-glycan binding sites of Cluc are required for the complete protein folding to form a stable catalytic center, for the proper conformation of substrate–protein interaction residues, or for both and that defects in the glycosylation modification are not related to secretion process and stability of the protein.Cypridina luciferase (Cluc), a secreted luminescent protein identified from Cypridina noctiluca, has two glycosylation sites. The effects of N-glycosylation on Cluc were evaluated by using site-directed mutants which were deficient in single or double glycol-chain modifications. The producibility and relative specific activity were apparently reduced in mutant Cluc although the thermostability and secretion efficiency were not affected, suggesting that N-glycosylation modifications are required for the complete protein folding and/or the proper conformation.
      PubDate: 2017-11-07T04:45:38.961119-05:
      DOI: 10.1111/php.12847
       
  • Long-term Genoprotection Effect of Sechium edule Fruit Extract Against UVA
           Irradiation in Keratinocytes
    • Authors: Elodie Metral; Walid Rachidi, Odile Damour, Frédéric Demarne, Nicolas Bechetoille
      Abstract: Photoprotection is essential to prevent the long-term deleterious effects of ultraviolet (UV), including skin cancer and photoaging. So far, there has been an increase in the use of natural bioactive phytochemicals for the development of more effective skin photoprotective agents. However, the molecular mechanisms underlying the photochemoprotection activity of such compounds remain largely unknown. The objective of this study was to investigate the effects of a Sechium edule fruit extract (SEE) in terms of photoprotection against UVA in primary human keratinocytes. We found that SEE protected keratinocytes against UVA-induced cytotoxicity, decreased the intracellular amounts of ROS and reduced oxidatively induced DNA lesions after UVA exposure. Furthermore, SEE decreased the induction of CPD lesions in UVA-irradiated keratinocytes and exhibited increased DNA repair of such photoproducts at 24 h post-exposure. Finally, using DNA repair biochips, we demonstrated that SEE-treated keratinocytes had DNA enzymatic repair activities more efficient for abasic sites, CPD and thymine glycols. Therefore, the benefits of SEE against UVA could be explained by a combination of antioxidant activity, the reduction in DNA damage and the enhancement of DNA repair capacities.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T03:10:24.165687-05:
      DOI: 10.1111/php.12854
       
  • Wellington Playgrounds Uncovered: An Examination of Solar Ultraviolet
           Radiation and Shade Protection in New Zealand
    • Authors: Ryan Gage; Chris O'Toole, Andrew Robinson, Anthony Reeder, Louise Signal, Christina Mackay
      Abstract: Providing effective shade in summer recreation spaces can reduce children's risk of skin cancer. This study explored the quantity and protective quality of shade in Wellington, New Zealand playgrounds. Two researchers visited 50 randomly-selected playgrounds during peak ultraviolet radiation (UVR) hours in summer and recorded the mean shade cover of playground equipment, seats, tables and open areas. A Solarmeter was used to calculate the proportion of UVR blocked by each built structure and tree. The results found that 95% of playground equipment and 64% of sitting and eating areas had no shade protection. Trees blocked a mean of 80.1% (95% CI: 66.0 – 94.1) of direct solar UVR, but mostly covered open areas, not playground equipment, seats and tables. The findings demonstrate that Wellington playgrounds have insufficient shade available. Increased shade in Wellington playgrounds is urgently needed to protect children from harmful UVR exposure, particularly through planting trees with heavy foliage and building structures with large, protective roofing. This may well be the case for other regions of NZ and for other countries where UVR exposure is dangerous. The method used in this study provides a reliable means to evaluate shade.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T02:50:53.281901-05:
      DOI: 10.1111/php.12855
       
  • Synthesis, Photophysical and Computational Study of Novel Coumarin Based
           Organic Dyes
    • Authors: Mahadev N. Kumbar; Madivalagouda S. Sannaikar, Saba Kauser J. Shaikh, Atulkumar A. Kamble, Manjunath N. Wari, Sanjeev R. Inamdar, Qiquan Qiao, N R Bhavya, M Mahendra, D Jagadeesh Prasad, Ravindra R. Kamble
      Abstract: A series of novel coumarin pyrazoline moieties combined with tetrazoles, 3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one, 6-chloro-3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one, 6-bromo-3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one and 6-bromo-3-(1-(4-bromophenyl)-4-(1H-tetrazol-5-yl)-1H pyrazol-3-yl)-2H-chromen-2-one 7(a-d) were designed and synthesized. Single crystal X-ray diffraction and their interactions were studied by Hirshfeld Surface Analysis. Thermal stabilities and electrochemical properties of these compounds were examined from Differential Scanning Calorimetry (DSC), Thermo gravimetric (TGA) and Cyclic Voltametric (CV) studies. Their spectroscopic properties were analysed in various alcohols and general solvents by UV-Vis absorption, fluorescence and time resolved spectroscopy. In addition, the ground and excited state electronic properties were investigated using density functional theory (DFT). The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and energy band gap (Eg) values have revealed the effect of substitution of halogens. The substitution has equally affected the ground and excited states of 7(a-d) compounds. The solvatochromism on absorption, fluorescence spectra and fluorescence lifetimes of these compounds were investigated. All these results showed the chromen-2-one of pyrazoline tetrazole derivatives could play an important role in photonic and electronic devices.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-06T05:20:29.325703-05:
      DOI: 10.1111/php.12852
       
  • Ultraviolet A Eye Irradiation Ameliorates Atopic Dermatitis via p53 and
           Clock Gene Proteins in NC/Nga Mice
    • Authors: Keiichi Hiramoto; Yurika Yamate, Satoshi Yokoyama
      Abstract: Atopic dermatitis (AD) is a widespread chronic skin condition that severely affects quality of life and can lead to more serious complications. Although ultraviolet (UV)A eye irradiation can exert various effects on the skin, it is unknown whether UVA can affect AD. To investigate potential associations, we used an NC/Nga mouse model of AD to study the effects of UVA eye irradiation. The eyes of mice were irradiated with a UVA dose of 100 kJ/m2 using a FL20SBLB-A lamp. Our histological data demonstrated that AD symptoms could be ameliorated by UVA eye irradiation. We also observed an increase in the levels of adrenocorticotropic hormone (ACTH), p53, and retinoid X receptor α (RXRα) in mice with UVA-irradiated eyes. In contrast, the levels of thymic stromal lymphopoetin (TSLP), period 2 (PER2), and differentiated embryo chondrocytes 1 (DEC1) protein were decreased in mice treated with UVA irradiation. Furthermore, UVA eye-irradiated mice exhibited reduced DEC1 and RXRα colocalization compared with nonirradiated mice. These results suggested that p53 and various clock gene proteins played important roles in the amelioration of AD symptoms observed after UVA eye irradiation; this technique may have therapeutic applications in AD.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-04T02:55:21.04077-05:0
      DOI: 10.1111/php.12853
       
  • Facile Fabrication of Porous ZnS and ZnO Films by Coaxial Electrospinning
           for Highly Efficient Photodegradation of Organic Dyes
    • Authors: Hua Wang; Liefeng Liang, Xinjian Cheng, Yanmei Luo, Sheng Sun
      Abstract: Porous ZnS and ZnO nano-crystal films were fabricated via a three-step procedure. First, Zn(CH3COO)2/Silk Fibroin nanofiber mats were prepared by coaxial electrospinning. Second, Zn(CH3COO)2/Silk Fibroin mats were immersed in NaS solution to react with S2− to obtain ZnS/Silk Fibroin nanofiber mats. Finally, ZnO porous films were prepared by calcination of ZnS/Silk Fibroin composite mat at 600°C in air atmosphere. When ZnS/Silk Fibroin mats were calcinated in nitrogen, ZnS/Carbon composite mats were obtained accordingly. The resulting porous films were fully characterized. The ZnO porous films were the aggregation of ZnO nano-crystal with hexagonal wurtzite structure. The seize of ZnO was estimated in the range of 10–20 nm. Both of the ZnS and ZnO nano-crystal films exhibited high photocatalytic activities for the photodegradation of Methylene blue and Rhodamine B. It was also found that ZnO porous films are better than ZnS/Carbon nanofiber mats. In addition, photocatalysis of a real wastewater sample from a printing and dyeing company was conducted. The ZnO porous films exhibited excellent performance to treat the real samples. Moreover, the porous ZnO nano-crystal photocatalyst could easily be recycled without notable loss of catalysis ability.Porous ZnS and ZnO nanocrystal films were fabricated via a three-step procedure starting from electrospinning. The nanocrystal films exhibited high photocatalytic activities for the photodegradation of methylene blue and rhodamine B. Also the films show excellent photocatalysis to a real wastewater sample from a printing and dyeing company.
      PubDate: 2017-11-03T14:01:01.138087-05:
      DOI: 10.1111/php.12836
       
  • Combination of Histopathology and FT-Raman Spectroscopy for the Study of
           Experimental Paracoccidioidomycosis in the Spleen
    • Authors: Elaine Sciuniti Benites Mansano; Gutierrez Rodriguês Morais, Edilaine Martins Moratto, Francielle Sato, Mauro Luciano Baesso, Antonio Neto Medina, Terezinha Inez Estivalet Svidzinski, Luzmarina Hernandes
      Abstract: Paracoccidioides brasiliensis (Pb) can disseminate through the lymphatic and hematogenic pathways. As a result the spleen and other lymphoid organs are targets of paracoccidioidomycosis. There are few studies describing this disease in the spleen and more detailed descriptions are required. This study combines Histopathology and Fourier Transform Raman Spectroscopy (FT-Raman) methods to study spleen infected by Pb. The Swiss mice were euthanized after 1, 2, 4 and 8 weeks of infection with Pb, and their spleens were removed for ex vivo analyzes. Histopathological evaluation revealed that the red pulp was the area most affected, presenting the highest concentration of yeasts, inflammatory cells and cells in apoptosis, with no observation of typical granuloma formation. The main physical–chemical changes were detected in the spectral ranges between 1730–1590 cm−1 and 1390–1280 cm−1 attributed to amide I and vibrational deformation mode of CH3 and CH2 molecules, respectively. The amide I was correlated to total protein content and CH3 and CH2 molecules to collagen of the spleen. The association between histological and physical–chemical methods enabled detection of several alterations in the spleen, including apoptosis, contributing to a better understanding of paracoccidioidomycosis, a tropical neglected disease.The spleen and other lymphoid organs are targets of paracoccidioidomycosis. We combined histopathology and FT-Raman methods to study spleen infected by Pb in Swiss mice. Histopathological evaluation revealed that the red pulp was the area most affected by infection. The results of physical-chemical analysis showed that the collagen structure was also affected by infection. The association of histological and physical-chemical techniques allowed a better understanding of the Pb action in spleen.
      PubDate: 2017-11-03T14:00:35.73524-05:0
      DOI: 10.1111/php.12840
       
  • Pterocarpus santalinus L. Regulated Ultraviolet B Irradiation-induced
           Procollagen Reduction and Matrix Metalloproteinases Expression Through
           Activation of TGF-β/Smad and Inhibition of the MAPK/AP-1 Pathway in
           Normal Human Dermal Fibroblasts
    • Authors: Wei Gao; Pei Lin, Eunson Hwang, Yushuai Wang, Zhengfei Yan, Hien T.T. Ngo, Tae-Hoo Yi
      Abstract: Ultraviolet light-induced reactive oxygen species (ROS) damage human skin and prematurely cause aging. A growing body of research is focusing on considering plants and plant-derived compounds as antiphotoaging therapeutic material. Pterocarpus santalinus L., as an Indian traditional medicine, possesses antidiabetic, anti-inflammatory and antioxidative effects. Here, we studied the antiphotoaging effects of ethanolic extract of P. santalinus L. heartwood (EPS) on ultraviolet radiation B (UVB)-irradiated normal human dermal fibroblasts (NHDFs). Results showed that EPS significantly inhibited the upregulation of matrix metalloproteinases and IL-6 caused by UVB irradiation, and suppressed UVB-induced phosphorylation of extracellular signal-regulated kinase, Jun N-terminal kinase and p38, as well as the activation of AP-1 transcription factors. Further study indicated that UVB-induced production of MMP-1 and IL-6 could be inhibited by PD 98059 (an ERK inhibitor) and SP600125 (A JNK inhibitor), implied that EPS inhibited UVB-induced MMP-1 and IL-6 secretion by inactivating MAPK signaling pathway. In addition, EPS possessed an excellent antioxidant activity, which could increase cytoprotective antioxidants such as HO-1, NQ-O1 expression by facilitating the nuclear accumulation of Nrf2. Treatment of NHDFs with EPS also recovered UVB-induced procollagen type I reduction by activating TGF-β/Smad pathway. These findings demonstrated that EPS had a potential effect against UVB-induced skin photoaging.Chronic exposure to UV radiation results in oxidative damage to skin, reflecting a clinically photoaging with loss of elasticity and tension. In this study, we demonstrated that EPS could be served as a potential photoprotective agent against UVB-induced skin aging. The protection mechanism involved in the increase of type-I procollagen synthesis and blocking of MMPs expression which was referred to the regulation of TGF-β/Smad and MAPK/AP-1 pathway. Furthermore, EPS could decrease the ROS level by accelerating the Nrf2 nuclear location and enhancing the expression of cytoprotective antioxidant.
      PubDate: 2017-11-03T13:55:40.049305-05:
      DOI: 10.1111/php.12835
       
  • The Different Resistance of Two Astragalus Plants to UV-B Stress is
           Tightly Associated with the Organ-specific Isoflavone Metabolism
    • Authors: Yang Liu; Jia Liu, Yu Wang, Ann Abozeid, Dong-Mei Tian, Xiao-ning Zhang, Zhong-Hua Tang
      Abstract: In this work, the changes in isoflavone levels and the expression of genes involved in their biosynthesis were studied in two Astragalus by UPLC-MS and real-time PCR after 10 days of UV-B treatment (λmax = 313 nm, 804 J m−2). Isoflavones were significantly induced by UV-B irradiation. The influence might be activated by the regulation of these target genes. Our results indicate that (1) the resistance of Astragalus membranaceus might not be as good as Astragalus mongholicus in the enhanced UV-B radiation environment; (2) the enhanced accumulation of calycosin and calycosin-7-glucoside with UV-B treatment in roots of A. mongholicus might be derived from formononetin which is synthesized in the leaves; (3) the glycosylation process could be stimulated and activated by the enhanced UV-B radiation in both A. mongholicus and A. membranaceus. In other words, glycosylation of isoflavones might play a crucial role for two Astragalus plants in response to UV-B stress. Overall, this study offered a feasible elicitation strategy to understand the accumulation pattern of isoflavone in A. mongholicus and A. membranaceus, and also provided a reference for the changes in isoflavone levels of Astragalus in UV-B enhanced environment in the future.The resistance of Astragalus membranaceus to UV-B radiation might not be as good as Astragalus mongholicus; glycosylation of isoflavones might play a crucial role for two Astragalus plants in response to UV-B stress.
      PubDate: 2017-10-26T15:35:49.030815-05:
      DOI: 10.1111/php.12841
       
  • Photodegradation of Eumelanin and Pheomelanin and Its Pathophysiological
           Implications
    • Authors: Shosuke Ito; Kazumasa Wakamatsu, Tadeusz Sarna
      Abstract: Eumelanin is photoprotective for pigmented tissues while pheomelanin is phototoxic. In this review, we summarize current understanding of how eumelanin and pheomelanin structures are modified by ultraviolet A (UVA) and also by visible light and how reactive oxygen species participate in those processes. Alkaline hydrogen peroxide oxidation was employed to characterize eumelanin and benzothiazole-type pheomelanin, giving pyrrole-2,3,5-tricarboxylic acid (PTCA) and thiazole-2,4,5-tricarboxylic acid (TTCA), respectively. Reductive hydrolysis with hydroiodic acid gives 4-amino-3-hydroxyphenylalanine (4-AHP) from the benzothiazine moiety of pheomelanin. The results show that the photoaging of eumelanin gives rise to free PTCA (produced by peroxidation in situ) and pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA, produced by cross-linking). The TTCA/4-AHP ratio increases with photoaging, indicating the conversion of benzothiazine to the benzothiazole moiety. Analysis of those markers and their ratios show that both eumelanin and pheomelanin in human retinal pigment epithelium melanosomes undergo extensive structural modifications due to their lifelong exposure to blue light. Using synthetic melanins, we also found that singlet oxygen, in addition to superoxide anions, is photogenerated and quenched upon UVA irradiation. The (patho)physiological significance of those findings is discussed in relation to the tanning process, to melanomagenesis in the skin and to age-related macular degeneration in the eyes.Photo-induced “aging” of melanin and its possible consequences are reviewed. We summarize how melanin structures are modified by ultraviolet A and blue light and how reactive oxygen species participates in those processes. The process of “aging” of melanin can be evaluated by spectrophotometry and HPLC analysis of melanin markers produced by chemical degradation methods. During photo-aging, melanin undergoes deterioration of its roles in photoprotection and cytoprotection and generate superoxide anion and singlet oxygen. The (patho)physiological significance of those findings is discussed in relation to the tanning process, to melanomagenesis in the skin and to age-related macular degeneration in the eyes.
      PubDate: 2017-10-26T15:31:11.101415-05:
      DOI: 10.1111/php.12837
       
  • Nicotinamide Adenine Dinucleotides Arrest Photoreduction of Class II DNA
           Photolyases in FADH˙ State
    • Authors: Elisabeth Ignatz; Yann Geisselbrecht, Stephan Kiontke, Lars-Oliver Essen
      Abstract: All light-sensitive members of the photolyase/cryptochrome family rely on FAD as catalytic cofactor. Its activity is regulated by photoreduction, a light-triggered electron transfer process from a conserved tryptophan triad to the flavin. The stability of the reduced flavin depends on available external electron donors and oxygen. In this study, we show for the class II photolyase of Methanosarcina mazei, MmCPDII, that it utilizes physiologically relevant redox cofactors NADH and NADPH for the formation of the semiquinoid FAD in a light-dependent reaction. Using redox-inert variants MmCPDII/W388F and MmCPDII/W360F, we demonstrate that photoreduction by NADH and NADPH requires the class II-specific tryptophan cascade of MmCPDII. Finally, we confirmed that mutations in the tryptophan cascade can be introduced without any substantial structural disturbances by analyzing crystal structures of MmCPDII/W388F, MmCPDII/W360F and MmCPDII/Y345F.The activity of the photolyase and cryptochrome family is regulated by photoreduction, a light-triggered electron transfer process from a conserved tryptophan triad to the flavin. The class II photolyase of Methanosarcina mazei utilizes the physiologically relevant redox cofactors NADH and NADPH for formation of the semiquinoid FAD in a light-dependent reaction. Photoreduction by NAD(P)H requires the class-II-specific tryptophan cascade of MmCPDII as shown by redox-inert variants. Mutations in the tryptophan cascade are causing almost no substantial structural disturbances in the crystal structures of MmCPDII/W388F, MmCPDII/W360F and MmCPDII/Y345F.
      PubDate: 2017-10-26T15:31:02.913723-05:
      DOI: 10.1111/php.12834
       
  • Protein 4.1R is Involved in the Transport of 5-Aminolevulinic Acid by
           Interaction with GATs in MEF Cells
    • Authors: Shuwei Ning; Qiaozhen Kang, Dandan Fan, Jingjing Liu, Chaoyue Xue, Xiaolin Zhang, Cong Ding, Jianying Zhang, Qian Peng, Zhenyu Ji
      Abstract: 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) has been successfully used in the treatment of cancers. However, the mechanism of 5-ALA transportation into cancer cells is still not fully elucidated. Previous studies have confirmed that the efficiency of 5-ALA-PDT could be affected by the membrane skeleton protein 4.1R. In this study, we investigated the role of 4.1R in the transport of 5-ALA into cells. Wild-type (4.1R+/+) and 4.1R gene knockout (4.1R−/−) mouse embryonic fibroblast (MEF) cells were incubated with 1 mm 5-ALA and different concentrations of specific inhibitors of GABA transporters GAT (1-3). Our results showed that the inhibition of GAT1 and GAT2 in particular markedly attenuated the intracellular PpIX production, reactive oxygen species (ROS) level and 5-ALA-induced photodamage. However, the inhibition of GAT3 did not show such effects. Further research showed that 4.1R−/− MEF cells had a lower expression of GAT1 and GAT2 than 4.1R+/+ MEF cells. Additionally, 4.1R directly bound to GAT1 and GAT2. Taken together, GAT1 and GAT2 transporters are involved in the uptake of 5-ALA in MEF cells. 4.1R plays an important role in transporting 5-ALA into cells via at least partly interaction with GAT1 and GAT2 transporters in 5-ALA-PDT.5-Aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) has been shown to be affected by the membrane skeleton protein 4.1R. This study investigated the role of 4.1R in the transport of 5-ALA into mouse embryonic fibroblast (MEF) cells. This figure shows that the inhibition of GABA transporters GAT1 and GAT2 by specific inhibitors attenuated the 5-ALA-induced photodamage, while the cell phototoxicity in the 4.1R−/− MEF cells was significantly lower than that in the 4.1R+/+ MEF cells. Our results show that 4.1R plays an important role in transporting 5-ALA into cells via interaction with GAT1 and GAT2 transporters in 5-ALA-PDT.
      PubDate: 2017-10-26T15:30:53.343227-05:
      DOI: 10.1111/php.12842
       
  • Lethal Effect of Photodynamic Treatment on Persister Bacteria
    • Authors: Oscar Juan Oppezzo; Ana Florencia Forte Giacobone
      Abstract: Persister bacteria tolerate bactericidal antibiotics due to transient and reversible phenotypic changes. As these bacteria can limit the effectiveness of antibiotics to eradicate certain infections, their elimination is a relevant issue. Photodynamic therapy seems suitable for this purpose, but phenotypic tolerance to it has also been reported for Pseudomonas aeruginosa. To test whether any phenotypic feature could confer tolerance against both antibiotics and photoinactivation, survivors from exposures to light in the presence of methylene blue were treated with ofloxacin, an antibiotic effective on nongrowing bacteria. Susceptibility to ofloxacin was normal in these bacteria in spite of their increased ability to survive photodynamic inactivation, suggesting the absence of cross-tolerance. It thus seemed possible to use one of these treatments to eliminate bacteria which had phenotypic tolerance to the other. To test this strategy, persister bacteria emerging from ofloxacin treatments were submitted to the action of light and methylene blue while the antibiotic remained in the bacterial suspension. Persisters lost their clonogenic ability under these conditions and the effects of the treatments seemed to be synergistic. These observations suggest that photodynamic antimicrobial therapy could be used as a complement to antibiotic treatments to eliminate persister bacteria from localized infections.This article shows that bacteria which acquire phenotypic tolerance to ofloxacin remain susceptible to the action of light in the presence of methylene blue. The absence of cross-tolerance suggest that, in addition to being an alternative to the use of antibiotics for eliminating resistant bacteria, photodynamic antimicrobial therapy could potentially be used to complement antibiotic treatments, helping to control localized infections which become chronic due to the emergence of persister bacteria.
      PubDate: 2017-10-26T15:30:47.342506-05:
      DOI: 10.1111/php.12843
       
  • A Closer Look at Dark Toxicity of the Photosensitizer TMPyP in Bacteria
    • Authors: Daniel B. Eckl; Linda Dengler, Marina Nemmert, Anja Eichner, Wolfgang Bäumler, Harald Huber
      Abstract: Photodynamic inactivation of bacteria (PIB) is based on photosensitizers which absorb light and generate reactive oxygen species (ROS), killing cells via oxidation. PIB is evaluated by comparing viability with and without irradiation, where reduction of viability in the presence of the photosensitizer without irradiation is considered as dark toxicity. This effect is controversially discussed for photosensitizers like TMPyP (5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluensulfonate). TMPyP shows a high absorption coefficient for blue light and a high yield of ROS production, especially singlet oxygen. Escherichia coli and Bacillus atrophaeus were incubated with TMPyP and irradiated with different light sources at low radiant exposures (μW per cm²), reflecting laboratory conditions of dark toxicity evaluation. Inactivation of E. coli occurs for blue light, while no effect was detectable for wavelengths>450 nm. Being more susceptible toward PIB, growth of B. atrophaeus is even reduced for light with emission>450 nm. Decreasing the light intensities to nW per cm² for B. atrophaeus, application of TMPyP still caused bacterial killing. Toxic effects of TMPyP disappeared after addition of histidine, quenching residual ROS. Our experiments demonstrate that the evaluation of dark toxicity of a powerful photosensitizer like TMPyP requires low light intensities and if necessary additional application of substances quenching any residual ROS.Photodynamic inactivation is evaluated by comparing viability of bacteria without and with irradiation. Any reduction of viability in the presence of a photosensitizer without irradiation is considered dark toxicity. In the presence of TMPyP, two bacteria types were exposed to low light intensities and viability of both decreased. However, when reducing light intensities to very small values close to darkness, that killing effect diminished and almost completely disappeared when adding a quencher like histidine. Thus, evaluation of dark toxicity requires low intensities of ambient light and if necessary application of quenchers.
      PubDate: 2017-10-26T15:30:37.677064-05:
      DOI: 10.1111/php.12846
       
  • LLLT Effects on Oral Keratinocytes in an Organotypic 3D Model
    • Authors: Fernanda G. Basso; Taisa N. Pansani, Diana G. Soares, Josimeri Hebling, Carlos Alberto Souza Costa
      Abstract: Several in vitro studies evaluated the cellular and molecular events related to interactions between phototherapy and target tissues, including oral keratinocytes and fibroblasts, providing elucidative data about phototherapy-induced healing. However, these interactions were limited to the application of a bidimensional cell culture model of oral mucosal cells. Thus, thisstudy evaluated the use of an organotypic oral epithelium model to elucidate the morphological and phenotypic responses of cells subjected to low-level laser therapy (LLLT). Oral keratinocytes were seeded in the ex vivo-produced oral mucosal equivalent (EVPOME) model, with a porcine acellular dermal matrix. LLLT was applied by means of the LaserTABLE device (780 nm, 25 mW) at 0.5, 1.5 and 3 J cm−2. After three irradiations, morphology, proliferation and gene expression of growth factors were assessed. LLLT and control groups presented similar morphological features, characterized by the formation of a stratified, differentiated and keratinized epithelium. LLLT enhanced the cell proliferation and gene expression of keratinocytes (hKGF) as well as epidermal (hEGF) growth factors. In general, analysis of these data shows that the three-dimensional cell culture model can be applied for phototherapy studies and that the positive effects of LLLT were confirmed by the use of an organotypic model.The use of tridimensional (3D) cell culture models provides better cell differentiation and unable interactions among cells and also of these cells to extracellular matrix. Therefore, these models provide more suitable and similar models to observe the effects of photobiomodulation. This study investigated the effects of low-level laser using a 3D oral epithelium model. Cells were irradiated with a laser diode prototype at different densities, which resulted in higher cell proliferation and differentiation as also gene expression of growth factors.
      PubDate: 2017-10-25T04:40:52.457091-05:
      DOI: 10.1111/php.12845
       
  • Synthesis of Pb9(PO4)6/Ag3PO4 Composite Photocatalysts With Enhanced
           Visible Light Photocatalytic Activity
    • Authors: Caiping Guo; Limin Song, Shujuan Zhang
      Abstract: Pb9(PO4)6/Ag3PO4 photocatalysts with different amounts of Pb9(PO4)6 were successfully synthesized by the ion exchange method. The catalysts were characterized by X-ray diffractometry (XRD), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Brunauer- Emmett-Teller (BET), Fourier transform infrared spectrometry (FT-IS), and ultraviolet-visible (UV-vis) spectroscopy. All Pb9(PO4)6/Ag3PO4 photocatalysts show much higher photocatalytic activities than pure Ag3PO4 under visible light irradiation in the methyl-orange (MO) decomposition. Especially, the 3.0 wt% Pb9(PO4)6/Ag3PO4 photocatalyst shows the highest photoactivity and also high stability after five cycles. The MO degradation rate during each cycle is almost maintained at 97%. Photo-electrochemical measurement of photocatalysts verified that the enhancing photocatalytic activity was resulted from the electron-hole pair high separation. The photocatalytic activity enhancement of Pb9(PO4)6/Ag3PO4 is closely related to •OH, the main active oxygen species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-20T05:45:32.605809-05:
      DOI: 10.1111/php.12851
       
  • Photochemistry and Photophysics of the 3-Styrylidenebenz[e]indanes
    • Authors: Jack Saltiel; Shipra Gupta, David W. Eaker, Andrew M. Kropp, V. K. Ratheesh Kumar
      Abstract: The photochemical and photophysical properties of the extended conformers of trans- and cis-1-(2-naphthyl)-2-phenylethenes (t- and c-NPEB) are strikingly different than those of their rigid analogues, trans- and cis-3-styrylidenebenz[e]indane (t- and c-BPE). The fluorescence quantum yield and lifetime at 25 °C in methylcyclohexane drop from 0.76 and 22.2 ns in t-NPEB to 0.0051 and 0.25 ns in t-BPE and there are complementary changes in the photoisomerization quantum yields. In both cases photoisomerization occurs in S2, a stilbenic excited state. The differences in behavior are traced to the diminished S1/S2 energy gap on the alkyl substitution afforded by the five-membered ring in BPE. The effect of viscosity on the torsional relaxation of t-BPE, evaluated in glycerol/methanol mixtures at 25 °C and in 95/5 and 99.9/0.1 glycerol/methanol (% v/v) as a function of T, is well accounted for by the medium enhanced barrier model. Absorption and fluorescence spectra of t-BPE in pure glycerol reveal aggregate formation. Quenching of t-BPE fluorescence in methylcyclohexane by tri-n-butylamine (TBA) leads to exciplex fluorescence. Comparison with analogous results for t-NPEB suggests that charge transfer involves primarily the naphthalenic S1 state in t-NPEB and the stilbenic S2 state in t-BPE.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T20:05:27.247415-05:
      DOI: 10.1111/php.12849
       
  • The Autophagy Receptor Adaptor p62 is Up-regulated by UVA Radiation in
           Melanocytes and in Melanoma Cells
    • Authors: Ashley Sample; Baozhong Zhao, Chunli Wu, Steven Qian, Xianglin Shi, Andrew Aplin, Yu-Ying He
      Abstract: UVA (315–400 nm) is the most abundant form of UV radiation in sunlight and indoor tanning beds. However, much remains to be understood about the regulation of the UVA damage response in melanocytes and melanoma. Here, we show that UVA, but not the shorter waveband UVB (280–315 nm), up-regulates adaptor protein p62 in an Nrf2- and reactive oxygen species (ROS)-dependent manner, suggesting a UVA-specific effect on p62 regulation. UVA-induced p62 up-regulation was inhibited by a mitochondria-targeted antioxidant or Nrf2 knockdown. In addition, p62 knockdown inhibited UVA-induced ROS production and Nrf2 up-regulation. We also report here a novel regulatory feedback loop between p62 and PTEN in melanoma cells. PTEN overexpression reduced p62 protein levels, and p62 knockdown increased PTEN protein levels. As compared with normal human skin, p62 was up-regulated in human nevus, malignant melanoma and metastatic melanoma. Furthermore, p62 was up-regulated in melanoma cells relative to normal human epidermal melanocytes, independent of their BRAF or NRAS mutation status. Our results demonstrated that UVA up-regulates p62 and induces a p62-Nrf2 positive feedback loop to counteract oxidative stress. Additionally, p62 forms a feedback loop with PTEN in melanoma cells, suggesting p62 functions as an oncogene in UVA-associated melanoma development and progression.UVA up-regulates the autophagy adaptor protein p62 in epidermal melanocytes and melanoma cells. Up-regulation of p62 requires reactive oxygen species (ROS) and Nrf2 activation, and p62 in turn promotes ROS generation and Nrf2 activation. Expression of p62 in melanoma cells also negatively regulates PTEN expression. Expression of PTEN in melanoma is sufficient to reduce p62 expression, creating a regulatory feedback loop.
      PubDate: 2017-10-08T12:40:32.811214-05:
      DOI: 10.1111/php.12809
       
  • Signaling Cascades Activated by UVB in Human Melanocytes Lead to the
           Increased Expression of Melanocyte-receptors, Endothelin B Receptor and
           c-KIT¶
    • Authors: Shuko Terazawa; Genji Imokawa
      Abstract: A single exposure of normal human melanocytes (NHMs) to ultraviolet B (UVB) radiation induces a distinct increase in the expression of c-KIT and endothelin B receptor (EDNRB) and up-regulates the expression of microphthalmia-associated transcription factor (MITF). In this review, we clarify the signaling mechanisms by which UVB stimulates the expression of MITF in NHMs, thus leading to up-regulation of those two important melanogenic receptors. The increased expression of MITF in UVB-exposed NHMs is accompanied by a markedly stimulated and prolonged phosphorylation of p38/CREB. The UVB-stimulated expression of c-KIT and EDNRB could be completely abolished by a p38 inhibitor concomitant with a reduced phosphorylation of CREB and a down-regulation of MITF expression. The UVB exposure of NHMs stimulates the phosphorylation of p38 and c-jun N-terminal kinase, but not ERK, followed by the increased phosphorylation of MSK1 and subsequently CREB. Post-irradiation treatment with the MSK1 inhibitor H89 significantly down-regulates the increased mRNA and protein expression of MITF, EDNRB and c-KIT in UVB-exposed NHMs. Our findings indicate for the first time that the increased expression of MITF that leads to the up-regulation of melanocyte-specific proteins in UVB-exposed NHMs is mediated via activation of the p38/MSK1/CREB axis but not the ERK/RSK/CREB axis.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-04T14:30:27.953974-05:
      DOI: 10.1111/php.12848
       
  • Physiological Doses of Red Light Induce IL-4 Release in Cocultures between
           Human Keratinocytes and Immune Cells
    • Authors: Cheryl Leong; Paul L. Bigliardi, Gopu Sriram, Veonice B. Au, John Connolly, Mei Bigliardi-Qi
      Abstract: Phototherapy is routinely used for the treatment of various skin conditions and targeted therapy of superficial cancers. However, the molecular mechanisms behind their biological effects and the need for efficacy enhancing photosensitizers are not well addressed. Particularly, not much is known about the inherent effect of light from the visible spectrum on cytokine release and its downstream effects in keratinocytes and immune cells located in skin and therefore exposed to light. To address this, we delivered calibrated doses of well-defined light qualities (380 to 660 nm) to cocultures of human keratinocytes and macrophage/dendritic cells in the absence or presence of the commonly used photosensitizer 8-methoxypsoralen (8-MOP). The experiments identified IL-4 as a key effector cytokine released by this coculture model with need for 8-MOP in the UVA1/blue (380 nm) and no requirement for photosensitizer in the red light spectrum (627 nm). 3D organotypic skin cultures treated with IL-4 showed thickening of the epidermal layer and delayed differentiation. However unlike IL-4 and UVA1/blue light treatment, red light did not reduce the expression of keratinocyte differentiation markers or increase signs of photo-oxidative damage. This supports the application of isolated red light as a possible alternative for photo-immunotherapy without need for additional photosensitizers.Red light-induced IL-4 release from keratinocyte and immune cell cocultures occurs without need for photosensitizer as compared to blue light-induced IL-4 release, which required pre-incubation with the photosensitizer 8-MOP. Increased IL-4 results in the delayed differentiation and increased epidermal hypertrophy in organotypic human skin cultures.
      PubDate: 2017-09-25T05:41:04.064595-05:
      DOI: 10.1111/php.12817
       
  • Facile Synthesis of BiOI Nanoparticles at Room Temperature and Evaluation
           of their Photoactivity under Sunlight Irradiation
    • Authors: Vahid Mahmoodi; Ali Ahmadpour, Tahereh Rohani Bastami, Mohammad Taghi Hamed Mousavian
      Abstract: In this study, highly photoactive BiOI nanoparticles (NPs) under sunlight irradiation were synthesized by a facile precipitation method using polyvinylpyrrolidone (PVP) at room temperature. The as-prepared catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) and UV–vis diffuse reflectance spectra (UV–vis DRS). The results of XRD showed that PVP did not have any significant effect on tetragonal crystalline structure of BiOI. Also, using different amounts of PVP in the synthesis led to different morphologies and sizes of BiOI particles. It was found that using 0.2 g of PVP in the synthesis method changed morphology from 1-μm platelets to NPs with size under 10 nm. In addition, the photocatalytic performance of prepared photocatalysts was evaluated in the photodegradation of reactive blue 19 (RB19) dye under sunlight irradiation. The BiOI synthesized using 0.2 g PVP (BiOI0.2) showed higher degradation efficiency compared to BiOI prepared without any additive. Excellent visible light photocatalytic properties of nano-scaled BiOI0.2 samples compared to BiOI platelets could be attributed to higher surface-to-volume ratio and narrow band-gap energy of as-prepared BiOI0.2 NPs.BiOI nanoparticles were synthesized by a green method at room temperature using ethanol and different amounts of polyvinylpirolidone (PVP). PVP played two major roles in the BiOI synthesis environment: (1) A stabilizer and protective agent, so inhibited the agglomeration of BiOI Nanoparticles (2) A template for nucleuses that restrains the growing process by encapsulation of nanoparticles. The size of BiOI nanoparticles synthesized with 0.2 g of PVP (BiOI0.2) was less than 10 nm and exhibited more than 95% degradation efficiency for photodegradation of Reactive Blue 19 after 120 min of sunlight irradiation.
      PubDate: 2017-09-25T05:35:49.277603-05:
      DOI: 10.1111/php.12832
       
  • Photophysical and Photochemical Properties of Naturally Occurring
           normelinonine F and Melinonine F Alkaloids and Structurally Related N(2)-
           and/or N(9)-methyl-β-carboline Derivatives
    • Authors: Federico A. O. Rasse-Suriani; Fernando S. García-Einschlag, Matías Rafti, Tobías Schmidt De León, Pedro M. David Gara, Rosa Erra-Balsells, Franco M. Cabrerizo
      Abstract: In the present work, we have synthesized and fully characterized the photophysical and photochemical properties of a selected group of N-methyl-β-carboline derivatives (9-methyl-β-carbolines and iodine salts of 2-methyl- and 2,9-dimethyl-β-carbolinium) in aqueous solutions, in the pH range 4.0–14.5. Moreover, despite the quite extensive studies reported in the literature regarding the overall photophysical behavior of N-unsubstituted βCs, this work constitutes the first full and unambiguous characterization of anionic species of N-unsubstituted βCs (norharmane, harmane and harmine), present in aqueous solution under highly alkaline conditions (pH> 13.0). Acid dissociation constants (Ka), thermal stabilities, room temperature UV–visible absorption and fluorescence emission and excitation spectra, fluorescence quantum yields (ФF) and fluorescence lifetimes (τF), as well as quantum yields of singlet oxygen production (ФΔ) have been measured for all the studied compounds. Furthermore, for the first time to our knowledge, chemometric techniques (MCR-ALS and PARAFAC) were applied on these systems, providing relevant information about the equilibria and species involved. The impact of all the foregoing observations on the biological role, as well as the potential biotechnological applications of these compounds, is discussed.Photophysical characterization of different acid-base species of normelinonine F and melinonine F alkaloids and other closely related 2-, 9-, and 2,9-substituted-β-carbolines in aqueous solution, in the pH range 4.0–14.5.
      PubDate: 2017-09-20T05:21:00.222542-05:
      DOI: 10.1111/php.12811
       
  • PARP-1/PAR Activity in Cultured Human Lens Epithelial Cells Exposed to Two
           Levels of UVB Light
    • Authors: Caroline S. Cencer; Shravan K. Chintala, Tenira J. Townsend, Daniel P. Feldmann, Mirna A. Awrow, Nahrain A. Putris, Mason E. Geno, Maria G. Donovan, Frank J. Giblin
      Abstract: This study investigated poly(ADP-ribose) polymerase-1 (PARP-1) activation in cultured human lens epithelial cells exposed to two levels of UVB light (312 nm peak wavelength), 0.014 and 0.14 J cm−2 (“low” and “high” dose, respectively). At the low dose, PARP-1 and poly(ADP-ribose) (PAR) polymers acted to repair DNA strand breaks rapidly with no subsequent major effects on either cell morphology or viability. However, following the high UVB dose, there was a dramatic second phase of PARP-1 activation, 90 min later, which included a sudden reappearance of DNA strand breaks, bursts of reactive oxygen species (ROS) formation within both the mitochondria and nucleus, a translocation of PAR from the nucleus to the mitochondria and an ultimate 70% loss of cell viability occurring after 24 h. The results provide evidence for an important role for PARP-1 in protecting the human lens epithelium against low levels of UVB light, and possibly participating in the triggering of cell death following exposure to toxic levels of radiation.Five minutes after a 2.5 min exposure of cultured human lens epithelial cells to 0.14 J cm−2 of UVB light, poly(ADP-ribose) (PAR) polymers were produced in the cell nucleus to assist in the repair of DNA and the polymers then disappeared. Surprisingly, 90 min after the exposure, PAR polymers were produced once again, but this time the polymers appeared to travel out of the nucleus to the cell mitochondria, possibly to initiate cell death.
      PubDate: 2017-09-15T07:42:24.923875-05:
      DOI: 10.1111/php.12814
       
  • Photocrosslinking of Polyglycidol and Its Derivative: Route to
           Thermoresponsive Hydrogels
    • Authors: Alicja Utrata-Wesołek; Iwona Żymełka-Miara, Agnieszka Kowalczuk, Barbara Trzebicka, Andrzej Dworak
      Abstract: Hydrogels of biologically well-tolerated, high-molar-mass polyglycidol (PGl) and its thermoresponsive derivative poly(glycidol-co-ethyl glycidyl carbamate) have been obtained by direct UV crosslinking in the solid state. Polymers with molar masses up to 1.45 × 106 g mol−1 were crosslinked in the presence of benzophenone or (4-benzoylbenzyl)trimethylammonium chloride as photosensitizers. The photosensitizer concentration was varied from 2 to 10 wt%. The influence of polymer composition and photosensitizer type and amount on the crosslinking efficiency, swelling and temperature behavior of the obtained hydrogels was investigated. The photocrosslinking of PGl and poly(glycidol-co-ethyl glycidyl carbamate) led to hydrogels with swelling degrees up to 1700%. The swelling degrees of the hydrogels decreased with the increase of the environmental temperature indicating the thermoresponsive nature of gels. The swelling of obtained gels can be controlled by varying the composition of the copolymer precursor and by the network density.Using photocrosslinking technique, it is possible to obtain hydrogels based on high-molar mass derivatives of polyglycidol, a polymer that is biocompatible and nontoxic. The hydrogels exhibit relatively high swelling degrees up to 1700%. The additional very interesting property of obtained hydrogels is their thermosensitivity, which depends upon the copolymer precursor composition and the network density. Thermoresponsive polymers and gels are of special interest as they can have many potential applications, for example in drug delivery, protein separation, biocatalyst immobilization or as a cell growth surfaces.
      PubDate: 2017-09-15T07:41:08.778667-05:
      DOI: 10.1111/php.12819
       
  • High-throughput Transcriptome Sequencing Reveals the Role of Anthocyanin
           Metabolism in Begonia semperflorens Under High Light Stress
    • Authors: Jiawan Wang; Meili Guo, Yonghua Li, Ronghua Wu, Kaiming Zhang
      Abstract: Begonia semperflorens is an ornamental perennial herb. The leaves of B. semperflorens turn red under increased light, which increases the ornamental value of the plant. The color of the leaves is determined by anthocyanin metabolism. In B. semperflorens leaves, anthocyanin metabolism is sensitive to external environmental conditions such as temperature, light and hormone levels. To explore this process in detail and to assess gene expression under high light stress, transcriptome analysis was performed by RNA sequencing using the sequencing-by-synthesis method. A total of 83 699 unigenes were isolated, and 51 754 unigenes were annotated using the NR, Swiss-Prot, KEGG, COG, KOG, GO and Pfam databases. Furthermore, many of the differentially expressed genes were related to factors associated with anthocyanin metabolism, which influences the expression of leaf color.Leaf colour is determined by anthocyanin metabolism. In Begonia semperflorens leaves, anthocyanin metabolism is sensitive to external environmental conditions such as light. To explore this process in detail and to assess gene expression in B. semperflorens under high light stress, transcriptome analysis was performed by RNA sequencing using the sequencing-by-synthesis method. Many of the differentially expressed genes were related to factors associated with anthocyanin metabolism, which influences the expression of leaf colour.
      PubDate: 2017-09-15T07:35:32.075725-05:
      DOI: 10.1111/php.12813
       
  • Analysis of the Electronic Structure of the Special Pair of a Bacterial
           Photosynthetic Reaction Center by 13C Photochemically Induced Dynamic
           
    • Authors: Marija Najdanova; Daniel Gräsing, A. Alia, Jörg Matysik
      Abstract: The origin of the functional symmetry break in bacterial photosynthesis challenges since several decades. Although structurally very similar, the two branches of cofactors in the reaction center (RC) protein complex act very differently. Upon photochemical excitation, an electron is transported along one branch, while the other remains inactive. Photochemically induced dynamic nuclear polarization (photo-CIDNP) magic-angle spinning (MAS) 13C NMR revealed that the two bacteriochlorophyll cofactors forming the “Special Pair” donor dimer are already well distinguished in the electronic ground state. These previous studies are relying solely on 13C-13C correlation experiments as radio-frequency-driven recoupling (RFDR) and dipolar-assisted rotational resonance (DARR). Obviously, the chemical-shift assignment is difficult in a dimer of tetrapyrrole macrocycles, having eight pyrrole rings of similar chemical shifts. To overcome this problem, an INADEQUATE type of experiment using a POST C7 symmetry-based approach is applied to selectively isotope-labeled bacterial RC of Rhodobacter (R.) sphaeroides wild type (WT). We, therefore, were able to distinguish unresolved sites of the macromolecular dimer. The obtained chemical-shift pattern is in-line with a concentric assembly of negative charge within the common center of the Special Pair supermolecule in the electronic ground state.An INADEQUAT type of experiment using a POST C7 symmetry-based approach is applied to selectively isotope-labeled bacterial RC of Rhodobacter (R.) sphaeroides WT in conjunction with photochemically induced dynamic nuclear polarization (Photo-CIDNP). The utility of the experiment for chemical shift assignment of direct carbon–carbon connectivities in photosynthetic macrocycles reduced the evaluation complexity of the various correlation networks originating from the bacterial RC. We therefore were able to distinguish unresolved sites of the macromolecular bacteriochlorophyll a dimer, and our data confirmed the coextensive negative charge within the common center of the Special Pair.
      PubDate: 2017-09-08T13:52:51.093156-05:
      DOI: 10.1111/php.12812
       
  • Resistance to Hydrogen Peroxide Highlights Gymnodinium catenatum
           (Dinophyceae) Sensitivity to Geomagnetic Activity
    • Authors: Paulo Vale
      Abstract: The chain-forming dinoflagellate Gymnodinium catenatum was exposed to hydrogen peroxide. Microscopical examination revealed striking dose–response alterations in chain formation above 245 μm: singlets replaced the dominance of long chain formations. These observations were valid for cells acclimated to halogen light. Under fluorescent light, cells were more resistant to modifications in chain length after H2O2 exposure. Growth along 9 h in the presence of extracellular H2O2 followed an hormesis response in both light regimes. Under halogen light conditions, alterations in chain formation and net growth were related to culture time, inocula concentration and geomagnetic activity (GMA) in the proceeding hours. Below a 16 nT threshold in GMA average growth was 0%, while above 16 nT it was circa +9%, independently if the local static magnetic field was altered by a permanent magnet or not. Mycosporine-like amino acids that can have an antioxidant role and are easily oxidized decreased from 7.1 to 6.5 pg cell−1 (P < 0.05) under halogen light and exposure to 245 μm H2O2. GMA, as well as UV-A, increased stress responsiveness that can momentarily protect cells from extracellular H2O2 addition. However, stress response is dependent on bio-availability of several micronutrients and macronutrients, many found at limiting concentrations in oceanic waters.The dinoflagellate Gymnodinium catenatum was exposed to hydrogen peroxide. Chain formation was reduced, with singlets replacing the dominance of long chain formations. Dose–response growth followed an hormesis response. Under halogen light conditions, alterations in chain formation and net growth were related to culture time, inocula concentration, and geomagnetic activity (GMA) in the proceeding hours. Prior exposure to GMA above 16 nT increased H2O2 resistance. Under fluorescent light conditions, with higher UVA radiation, basal concentration of mycosporine-like amino acids was higher, conferring higher resistance to alterations in chain formation due to its protective role.
      PubDate: 2017-09-08T13:51:21.079874-05:
      DOI: 10.1111/php.12815
       
  • Photochemical Reaction Between 1,2-Naphthoquinone and Adenine in Binary
           Water-Acetonitrile Solutions
    • Authors: Qiaohui Zhou; Yaxiong Wei, Xiang Liu, Lin Chen, Xiaoguo Zhou, Shilin Liu
      Abstract: The photochemical reaction between 1,2-naphthoquinone (NQ) and adenine was investigated using nanosecond time-resolved laser flash photolysis. With photolysis at 355 nm, the lowest triplet state T1 of NQ was produced via intersystem crossing from its singlet excited state. The triplet-triplet absorption of the state contributes three bands of transient spectra at 374, 596 and 650 nm, respectively, in pure acetonitrile and binary water-acetonitrile solutions. In the presence of adenine, the observation of A·+ (at 363 nm) and NQ+H· radical (at 343 and 485 nm) indicates a multistep mechanism of electron transfer process followed by a proton transfer between 3NQ* and adenine. By fitting with the Stern-Volmer relationship, the quenching rate constant kq of 3NQ* by adenine in binary water-acetonitrile solutions (4/1, volume ratio, v/v) is determined as 1.66 × 109 m−1 s−1. Additionally, no spectral evidence confirms the existence of electron transfer between 3NQ* with thymine, cytosine and uracil.A multistep mechanism of electron transfer between the triplet NQ and adenine was clarified, and the bimolecular reaction rate constant was determined in binary water-acetonitrile solutions.
      PubDate: 2017-09-08T13:50:36.621861-05:
      DOI: 10.1111/php.12808
       
  • UVA-Induced DNA Damage and Apoptosis in Red Blood Cells of the African
           Catfish Clarias gariepinus
    • Authors: Alaa El-Din Hamid Sayed
      Abstract: Ultraviolet-A light (UVA)-induced DNA damage and repair in red blood cells to investigate the sensitivity of African catfish to UVA exposure is reported. Fishes were irradiated with various doses of UVA light (15, 30, and 60 min day−1 for 3 days). Morphological and nuclear abnormalities in red blood cells were observed in the fish exposed to UVA compared with controls. Morphological alterations such as acanthocytes, crenated cells, swollen cells, teardrop-like cells, hemolyzed cells, and sickle cells were observed. Those alterations were increased after 24 h exposure to UVA light and decreased at 14 days after exposure. The percentage of apoptosis was higher in red blood cells exposed to higher doses of UVA light. No micronuclei were detected, but small nuclear abnormalities such as deformed and eccentric nuclei were observed in some groups. We concluded that exposure to UVA light induced DNA damage, apoptosis, and morphological alterations in red blood cells in catfish; however, catfish were found to be less sensitive to UVA light than wild-type medaka.The African catfish (Clarias gariepinus) was exposed to UVA as a hemotoxic agent. Apoptosis was recorded in high degree after 24 h postexposure and then decreased in level after 14 days from exposure time. DNA damage and repair response were detected. UVA exposure effect was dose dependent. Erythrocyte alterations and nuclear abnormalities were observed.
      PubDate: 2017-09-08T13:45:34.344203-05:
      DOI: 10.1111/php.12818
       
  • Solvothermal Synthesis of Cs0.33WO3/LDHs Composite as a Novel Visible
           Light Droven Photocatalyst
    • Authors: Dan Zhang; Taotao Ji, Jingang Yu, Xinyu Jiang, Feipeng Jiao
      Abstract: A novel Cs0.33WO3/LDHs (CWLDH) composite was synthesized by simple two steps solvothermal method and first investigated as the photocatalyst for tetracycline (TC) and Congo red (CR) degradation under visible light irradiation. The CWLDH heterostructures catalysts were characterized by XRD, UV-vis, SEM, XPS and BET. The composite CWLDH showed enhanced photocatalytic activity compared with pure Cs0.33WO3 and NiAl-LDH under identical experimental conditions. The enhanced photocatalytic activity was mainly attributed to the higher visible-light adsorbing ability, efficient electron-hole separation, and prolonged lifetimes of photogenerated charges. The photocatalyst presented a high photocatalytic activity (92%) at the optimum of CWLDH-3 and initial TC concentration of 40 mg/L. Besides, the degradation efficiency of TC is higher than 75% for reused CWLDH after four cycles, demonstrating that it could be used as a potential catalyst with good photocatalytic activity, stability, and reusability. According to the experimental results, a possible photocatalytic mechanism of CWLDH was discussed.This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-07T08:50:21.557995-05:
      DOI: 10.1111/php.12838
       
  • Continuum Electrostatic Calculation on Bovine Rhodopsin: Protonation and
           the Effect of the Membrane Potential
    • Authors: Elisa Bombarda; G. Matthias Ullmann
      Abstract: In this work, we calculate the protonation probabilities of titratable residues of bovine rhodopsin using the Poisson-Boltzmann equation. We also consider the influence of the membrane potential. Our results indicate that at physiological pH, the titratable groups directly involved in photosensing, namely Glu113, Glu181 and the retinal Schiff base, are charged. In contrast, the residues Asp83, Glu122, and His211, which are buried in the membrane, are uncharged. However, since these later residues are localized in the middle of the membrane, they are exposed to the membrane potential more strongly, which may have important functional implications. Despite of their large distance, Asp83 and Glu122 interact relatively strongly. Since these two residues are in contact with opposite sides of the membrane, the membrane potential has different effects on them, which allows an enhancement of the membrane potential signal. An analysis of the different contributions to the protonation energy indicates that conformational changes that reduce the desolvation penalty of Asp83, Glu122, and His211 may lead to a complex protonation pattern change that allows an influence of the membrane potential on the function of rhodopsin. The high degree of evolutionary conservation of these three buried residues support the idea of their functional importance. Our results are inline with many experimental findings and lead to new ideas that can be experimentally tested.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-24T08:36:00.170592-05:
      DOI: 10.1111/php.12777
       
  • High-level Ab Initio Absorption Spectra Simulations of Neutral, Anionic
           and Neutral+ Chromophore of Green Fluorescence Protein Chromophore Models
           in Gas Phase and Solution
    • Authors: Ivelina Georgieva; Adelia J. A. Aquino, Natasha Trendafilova, Hans Lischka
      Abstract: Semi-classical ab initio simulations of the absorption spectra of neutral and anionic p-hydroxybenzylidene-2,3-dimethylimidazolinone (p-HBDI), a model chromophore of Green Fluorescent Protein (GFP) and of a positively charged neutral (N+)-HBDI chromophore model were performed in gas phase with the resolution-of-identity algebraic diagrammatic construction through second-order (RI-ADC(2)) method. The calculated absorption spectra in gas phase are composed of one band centered at 3.51 eV (HBDI), 2.50 eV (HBDI-) and 3.02 eV ((N+)-HBDI) owing to the absorption of the first 1ππ* transition. Band maxima are red-shifted by ~0.1 eV with respect to the corresponding vertical energies. The COSMO-RI-ADC(2) calculations of the first vertical excitation energy of HBDI, HBDI- and (N+)-HBDI forms in polar solution including microsolvation simulate the observed solvent red-shift for neutral HBDI and the solvent blue-shift of the HBDI- and (N+)-HBDI forms. The state-specific solvation approach applied to TDDFT calculations reproduced the experimental solvent shifts for the three HBDI forms, demonstrating a more accurate theoretical description as compared to the linear-response TDDFT approach.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-24T00:11:10.833533-05:
      DOI: 10.1111/php.12778
       
  • FTIR Analysis of a Light-driven Inward Proton Pumping Rhodopsin at 77 K
    • Authors: Shota Ito; Shinya Sugita, Keiichi Inoue, Hideki Kandori
      Abstract: Parvularcula oceani xenorhodopsin (PoXeR) is a light-driven inward proton pump that was discovered from deep ocean marine bacteria. PoXeR is categorized into the same family of Anabaena sensory rhodopsin (ASR) that functions as a photochromic sensor. In this paper, we applied light-induced difference Fourier-transform infrared (FTIR) spectroscopy to PoXeR at 77 K, and the obtained spectra were compared with those of ASR. The structure and structural changes in the primary processes of PoXeR are common to all microbial rhodopsins. The red-shifted K formation (PoXeRK) was accompanied by retinal photoisomerization from the all-trans to 13-cis form resulting in a distorted structure of the retinal. The observed hydrogen out-of-plane (HOOP) vibrations were sensitive to H/D exchange, indicating that the chromophore distortion by retinal isomerization is located near the Schiff base region in PoXeR. The hydrogen-bonding strength of the protonated Schiff base is similar between PoXeR and ASR, whose acceptor is presumably a water molecule. Unlike ASR, however, PoXeR contains strongly hydrogen-bonded water (O-D stretch at 2277 cm−1 in D2O), which is also the case for outward proton pumps. The detailed structure, structural changes upon retinal photoisomerization, as well as functional correlation in PoXeR are discussed based on the present FTIR study.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T17:23:42.030513-05:
      DOI: 10.1111/php.12771
       
  • On the Simulation of Two-dimensional Electronic Spectroscopy of
           Indole-containing Peptides
    • Authors: Angelo Giussani; Jacopo Marcheselli, Shaul Mukamel, Marco Garavelli, Artur Nenov
      Abstract: A benchmark study of low-cost multi-configurational CASSCF/CASPT2 schemes for computing the electronic structure of indole is presented. This facilitates the simulation of near-ultraviolet (UV) pump visible (VIS) probe (i.e. two-color) two-dimensional electronic spectra (2DES) of homo- and hetero-aggregates as well as for processing of multiple snapshots from molecular dynamics simulations. Fingerprint excited state absorption signatures of indole are identified in a broad spectral window between 10 and 25 kcm−1. The 18-24 kcm−1 spectral window which has no absorption of the monomer and non-interacting aggregates, is ideally suited to embed charge transfer signatures in stacked aggregates. The small peptide Trp-cage, containing a tryptophan and a tyrosine amino acids, having indole and phenol as side chains, respectively, serves to prove the concept. Clear charge transfer signatures are found in the proposed spectral window for an inter-chromophore distance of 5 Å making near-UV pump VIS probe 2DES a suitable technique for resolving closely packed aggregates. We demonstrate that 2DES utilizing ultra-short pulses has the potential to resolve the nature of the spectroscopically resolved electronic states and that the line shapes of the excited state absorption signals can be correlated to the polarity of the relevant states.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T17:22:45.362785-05:
      DOI: 10.1111/php.12770
       
  • Issue Information
    • Pages: 1333 - 1334
      PubDate: 2017-11-16T14:15:25.516842-05:
      DOI: 10.1111/php.12634
       
  • Introduction—Festschrift in Honor of Prof. Volker Buß
    • Authors: Igor Schapiro; Oliver Weingart
      Pages: 1335 - 1335
      PubDate: 2017-11-16T14:15:20.68045-05:0
      DOI: 10.1111/php.12850
       
  • Protonation–state-Coupled Conformational Dynamics in Reaction Mechanisms
           of Channel and Pump Rhodopsins
    • Authors: Ana-Nicoleta Bondar; Jeremy C. Smith
      Pages: 1336 - 1344
      Abstract: Channel and pump rhodopsins use energy from light absorbed by a covalently bound retinal chromophore to transport ions across membranes of microbial cells. Ion transfer steps, including proton transfer, can couple to changes in protein conformational dynamics and water positions. Although general principles of how microbial rhodopsins function are largely understood, key issues pertaining to reaction mechanisms remain unclear. In this review, we compare the protonation-coupled dynamics of pump and channelrhodopsins, highlighting the roles that water dynamics, protein electrostatics and protein flexibility can have in ion transport mechanisms. We discuss observations supporting important functional roles of inter- and intra-helical carboxylate/hydroxyl hydrogen-bonding motifs. As specific examples, we use the proton pump bacteriorhodopsin, the sodium pump KR2, channelrhodopsins and Anabaena sensory rhodopsin. We outline the usefulness of theoretic biophysics approaches to the study of retinal proteins, challenges in studying the hydrogen-bond dynamics of rhodopsin active sites, and implications for conformational coupling in membrane transporters.Putative roles of carboxylate/hydroxyl motifs in membrane proteins. (A) The hydroxyl group serves as intermediate carrier for the proton. Such a proton-transfer path has been discussed for bacteriorhodopsin. (B) Coupling between intra- and inter-helical hydrogen bonding.
      PubDate: 2017-07-25T02:40:50.221787-05:
      DOI: 10.1111/php.12790
       
  • New Perspectives on an Old Issue: A Comparative MS-CASPT2 and OM2-MRCI
           Study of Polyenes and Protonated Schiff Bases
    • Authors: Irina Dokukina; Christel M. Marian, Oliver Weingart
      Pages: 1345 - 1355
      Abstract: Polyenic systems are involved in light perception of numerous living organisms. Although a π-conjugated backbone is a common feature of all polyenes, their photophysics may vary. We provide a comparative quantum mechanical study of low-lying S1 and S2 excited states in short (3-5 double bonds) symmetric all-trans linear polyenes and corresponding protonated Schiff bases. In our investigation, we use the well-established ab initio multireference CASPT2 approach and benchmark the efficient semiempirical OM2-MRCI approach against it. For all protonated Schiff bases, MS-CASPT2 results in two distinct S1 minima with inverted and noninverted bond length pattern, respectively. We find that OM2-MRCI is a computationally affordable and reliable alternative to MS-CASPT2 for investigations of polyenic systems, particularly when highly demanding calculations (e.g. excited-state dynamics) need to be performed.Ground and excited states of small linear polyenes and corresponding Schiff-base models are investigated with CASSCF, MS-CASPT2 and semiempirical OM2-MRCI methodologies.
      PubDate: 2017-10-16T07:40:41.287026-05:
      DOI: 10.1111/php.12833
       
  • A Quantum-mechanical Study of the Binding Pocket of Proteorhodopsin:
           Absorption and Vibrational Spectra Modulated by Analogue Chromophores
    • Authors: Francesco Buda; Tom Keijer, Srividya Ganapathy, Willem J. de Grip
      Pages: 1399 - 1406
      Abstract: Proteorhodopsin is a light-driven proton pumping membrane protein related to bacteriorhodopsin. It contains an all-trans retinal A1 chromophore covalently bound to a lysine residue via a protonated Schiff base. In this study, we exploited density functional theory (DFT) calculations to investigate the retinal binding pocket in the dark state and after mimicking photoisomerization. The model of the binding pocket is constructed incrementally by adding the residues near the retinal that are necessary to ensure a stable protonated Schiff base. The presence of a few water molecules near the Schiff base turns out to be an essential feature of the model. The absorption properties are then studied using time-dependent DFT (TDDFT) and compared to experimental data to further validate the structural model and to assess the accuracy of the computational setting. It is shown that TDDFT is able to reproduce the main absorption peak accurately and to quantitatively determine the spectral shift induced by substituting the native all-trans retinal A1 chromophore with different retinal analogues. Moreover, ab initio molecular dynamics simulations are performed to investigate the vibrational spectra of our models before and after isomerization. Specific differences in the vibrational spectra are identified that provide further insight into experimental FTIR difference spectra.Green proteorhodopsins are a large class of light-driven proton pumping membrane proteins. As no crystal structure is available for this system, we use a computational strategy based on DFT to build a model of the binding pocket from a homology structure. This minimal model is able to accurately predict the absorption spectrum for the native chromophore and the spectral shift induced by different retinal analogues. The crucial role of water molecules in the binding pocket and the hydrogen bond network rearrangement upon photoisomerization are also discussed.
      PubDate: 2017-07-25T03:51:53.882317-05:
      DOI: 10.1111/php.12800
       
  • Study on the Basic Performance of Three-phase Fluidized Bed Equipment for
           Solar Photocatalysis–Membrane Separation
    • Authors: Li Sha; Liping Xie, Miaomiao Li, Xuening Fei, Jinshan Du, Chenxi Zou
      Pages: 1407 - 1413
      Abstract: In this study, three-phase fluidized bed equipment for the solar photocatalysis–membrane separation (E-SPME), comprising solar photocatalytic degradation and membrane separation zones, was first introduced, and the photocatalytic degradation of acid red B wastewater (ARBW) with a TiO2 photocatalyst was investigated using the E-SPME. The experimental results indicated the circulating flow of wastewater between the two zones and the increase in the ARBW photocatalytic degradation efficiency with decreasing membrane flux. The same experimental phenomenon was observed with the change in the aeration rate in the lower water tank from 0.10 to 0.40 m3 h−1, but the degradation efficiency started to decrease with further increase in the aeration rate to 0.50 m3 h−1. The degradation efficiency on a clear day was greater than that on a cloudy day; however, it was significantly improved with the opened UV lamps on a cloudy day. The steady operation of the E-SPME was still possible by the opening of the UV lamps on completely cloudy and clear days with a solar light intensity of
      PubDate: 2017-07-21T13:50:42.041369-05:
      DOI: 10.1111/php.12791
       
  • A Boron 2-(2′-pyridyl) Imidazole Fluorescence Probe for Bovine Serum
           Albumin: Discrimination over Other Proteins and Identification of Its
           Denaturation
    • Authors: Chunlin Liu; Wei Yang, Jinya Du, Ping Shen, Changying Yang
      Pages: 1414 - 1422
      Abstract: Boron 2-(2′-pyridyl) imidazole complex (BOPIM) derivatives, BOPIM-1 and BOPIM-2, involving twisted intra-molecular charge transfer (TICT) characteristic, were investigated to probe bovine serum albumin (BSA). BOPIM-1 was demonstrated to be an efficient fluorescence probe to discriminate BSA from other proteins including human serum albumin (HSA). The encapsulation of BOPIM-1 in the hydrophobic subdomain IIA of BSA inhibited the TICT state and resulted in 70-fold emission enhancement of BOPIM-1. Besides, it was found that BOPIM-1 could distinguish denatured BSA from the native, due to the difference of 15 nm emission wavelength at least. The denaturation of BSA leads to the exposure of binding sites and resulted in an increase in the accessibility of the fluorophore to the BSA cavity, which made a great contribution to the further restraint of TICT state of BOPIM-1. The tracking of BSA denaturizing process was easily achieved, through the change of BOPIM-1 emission wavelength from 485 to 465 nm. Thus, a promising pharmacological dual-functional probe was provided for both the selective recognization of BSA and the identification of denatured BSA from the native.A dual-functional fluorescence probe BOPIM-1 is for both sensitively discriminating bovine serum albumin (BSA) from other proteins and detecting denatured BSA.
      PubDate: 2017-07-31T05:25:49.846838-05:
      DOI: 10.1111/php.12789
       
  • Mechanistic Studies on the Peroxyoxalate Chemiluminescence Using Sodium
           Salicylate as Base Catalyst
    • Authors: Glalci A. Souza; André P. Lang, Wilhelm J. Baader
      Pages: 1423 - 1429
      Abstract: Mechanistic studies on the peroxyoxalate chemiluminescence are often conducted with imidazole as base and nucleophilic catalyst. However, it is also known that this compound, at high concentrations, leads to a drastic reduction in the chemiluminescence quantum yields, apparently due to the destruction of the high-energy intermediate. Consequently, the search for new catalysts for this transformation is of importance for mechanistic studies as well as analytical application. Therefore, we report here a study on the mechanism of the peroxyoxalate reaction with sodium salicylate as base catalyst, which has already been utilized in this reaction; however, no detailed mechanistic investigation is known. In this work, a kinetic study on the sodium salicylate-catalyzed reaction of bis(2,4,6-trichlorophenyl) oxalate with hydrogen peroxide using 9,10-diphenylanthracene as activator is reported, where observed rate constants, singlet quantum yields and activation parameters are determined in different reaction conditions, leading to the formulation of a general mechanistic reaction scheme.The peroxyoxalate reaction is studied with sodium salicylate as catalyst which, contrarily to imidazole, acts only as base, not as nucleophilic, catalyst. Reproducible results are obtained, and a general reaction mechanism is proposed.
      PubDate: 2017-07-25T02:40:30.904595-05:
      DOI: 10.1111/php.12797
       
  • 31P NMR Evidence for Peroxide Intermediates in Lipid Emulsion
           Photooxidations: Phosphine Substituent Effects in Trapping
    • Authors: Prabhu P. Mohapatra; Callistus O. Chiemezie, Arina Kligman, Michele M. Kim, Theresa M. Busch, Timothy C. Zhu, Alexander Greer
      Pages: 1430 - 1438
      Abstract: Intralipid is a lipid emulsion used in photodynamic therapy (PDT) for its light scattering and tissue-simulating properties. The purpose of this study is to determine whether or not Intralipid undergoes photooxidation, and we have carried out an Intralipid peroxide trapping study using a series of phosphines [2′-dicyclohexylphosphino-2,6-dimethoxy-1,1′-biphenyl-3-sulfonate, 3-(diphenylphosphino)benzenesulfonate, triphenylphosphine-3,3′,3′′-trisulfonate and triphenylphosphine]. Our new findings are as follows: (1) An oxygen atom is transferred from Intralipid peroxide to the phosphine traps in the dark, after the photooxidation of Intralipid. 3-(Diphenylphosphino)benzenesulfonate is the most suitable trap in the series owing to a balance of nucleophilicity and water solubility. (2) Phosphine trapping and monitoring by 31P NMR are effective in quantifying the peroxides in H2O. An advantage of the technique is that peroxides are detected in H2O; deuterated NMR solvents are not required. (3) The percent yield of the peroxides increased linearly with the increase in fluence from 45 to 180 J cm−2 based on our trapping experiments. (4) The photooxidation yields quantitated by the phosphines and 31P NMR are supported by the direct 1H NMR detection using deuterated NMR solvents. These data provide the first steps in the development of Intralipid peroxide quantitation after PDT using phosphine trapping and 31P NMR spectroscopy.Phosphines are shown to be efficient trapping agents for peroxides in postphotooxidation/photoreactions of Intralipid.
      PubDate: 2017-09-04T13:31:35.691783-05:
      DOI: 10.1111/php.12810
       
  • A Photosensitizer Lanthanide Nanoparticle Formulation that Induces Singlet
           Oxygen with Direct Light Excitation, But Not By Photon or X-ray Energy
           Transfer
    • Authors: Rima Chouikrat; Francis Baros, Jean-Claude André, Régis Vanderesse, Bruno Viana, Anne-Laure Bulin, Christophe Dujardin, Philippe Arnoux, Marc Verelst, Céline Frochot
      Pages: 1439 - 1448
      Abstract: We report the design and synthesis of europium-doped gadolinium oxysulfide nanoscintillators Gd2O2S:Eu3+ conjugated with two different photosensitizers (PSs): a zinc chlorin (ZnTPC) and a zinc phtalocyanine (ZnPc) by covalent bonding through a layer of N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA). These conjugates were designed to be activated under X-ray excitation to allow a photodynamic effect, although this desired outcome was not achieved in this study. The monodispersed nanoparticles of ∼70 nm diameter were pegylated to be stabilized in aqueous suspension. It was shown that the PSs conserved their photophysical properties once conjugated to the nanoscintillator and efficient singlet oxygen was obtained upon photo-irradiation. However, no energy transfer was observed from the nanoscintillator to the photosensitizer neither under photo- nor X-ray irradiation.We report the design and synthesis of europium-doped gadolinium oxysulfide nanoscintillators Gd2O2S:Eu3+ conjugated with two different photosensitizers (PS) by covalent bonding through a layer of N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA). PEG was added. These conjugates were designed to be activated under X-ray excitation to allow a photodynamic effect, although this desired outcome was not achieved in this study. It was shown that the PSs conserved their photophysical properties once conjugated to the nanoscintillator and efficient singlet oxygen was obtained upon photo-irradiation. However, no energy transfer was observed from the nanoscintillator to the photosensitizer neither under photo- nor X-ray irradiation.
      PubDate: 2017-07-25T02:41:26.556331-05:
      DOI: 10.1111/php.12799
       
  • Spectral Remittance and Transmittance of Visible and Infrared-A Radiation
           in Human Skin—Comparison Between in vivo Measurements and Model
           Calculations
    • Authors: Helmut Piazena; Hans Meffert, Ralf Uebelhack
      Pages: 1449 - 1461
      Abstract: The aim of the study was to assess the interindividual variability of spectral remittance and spectral transmittance of visible and infrared-A radiations interacting with human skin and subcutaneous tissue, and direct measurements were taken in vivo using healthy persons of different skin color types. Up to wavelengths of about 900 nm, both spectral remittance and spectral transmittance depended significantly on the individual contents of melanin and hemoglobin in the skin, whereas the contents of water and lipids mainly determined spectral slopes of both characteristics of interaction for wavelengths above about 900 nm. In vivo measured data of spectral transmittance showed approximately similar decreases with tissue thickness between about 900 nm and 1100 nm as compared with model data which were calculated using spectral absorption and scattering coefficients of skin samples in vitro published by different authors. In addition, in vivo measured data and in vitro-based model calculations of spectral remittance were approximately comparable in this wavelength range. In contrast, systematic but individually varying differences between both methods were found for both spectral remittance and spectral transmittance at wavelengths below about 900 nm, where interaction of radiation was significantly affected by both melanin and hemoglobin.We assessed interindividual variability of spectral remittance/transmittance of visible/infrared-A radiation interacting with human skin in vivo. Below 900 nm, both spectral remittance and transmittance depended on melanin and hemoglobin content in the skin, whereas water and lipid contents determined spectral slopes for wavelengths>900 nm. In vivo data showed similar decreases with tissue thickness from 900 to 1100 nm as compared with model data calculated using published in vitro spectral absorption and scattering coefficients. In addition, in vivo and in vitro values of spectral remittance were comparable above 900 nm, whereas systematic but individually varying differences were found below 900 nm.
      PubDate: 2017-07-27T02:35:40.65364-05:0
      DOI: 10.1111/php.12785
       
  • An In Vitro Model for Fibroblast Photoaging Comparing Single and Repeated
           UVA Irradiations
    • Authors: Wongnapa Nakyai; Aurasorn Saraphanchotiwitthaya, Céline Viennet, Philippe Humbert, Jarupa Viyoch
      Pages: 1462 - 1471
      Abstract: The current method for efficient evaluation of antiphotoaging compounds is an in vitro skin culture model using a single ultraviolet A (UVA) irradiation of fibroblasts. However, skin photoaging is caused by repeated exposure to UVA radiation. The objective of this study was to develop an appropriate model for in vitro skin photoaging by comparing the different effects of single (5 J cm−2) and repeated exposures (5 J cm−2 × 3 times) of fibroblasts to UVA irradiation. Our results demonstrated that a single and repeated exposure to UVA irradiation had different effects on fibroblasts. In the single UVA-irradiated group, collagen lattice contraction and the protein levels of type I procollagen and matrix metalloproteinase-1 (MMP-1) increased, while the levels of fibronectin and alpha-smooth muscle actin (α-SMA) were unchanged, compared to levels in the non-UVA-irradiated group (control). In contrast, repeated UVA exposure significantly induced G0/G1 cell cycle arrest, reduced collagen lattice contraction and type I procollagen and fibronectin expression, and increased MMP-1 expression. There was no difference in α-SMA expression when comparing repeatedly irradiated and non-UVA-irradiated fibroblasts. Our findings clearly indicate that repeated UVA irradiation of cells induces malfunctions found in photoaged skin and is an appropriate in vitro skin model of photoaging.The different effects between single and repeated exposure of fibroblasts to UVA (5 J cm−2) radiation on the expressions of proteins and the contractile capacity were determined. The single dose of UVA radiation remakably increased expressions of type I procollagen and MMP-1 of fibroblasts. Moreover, the contractile capacity, measured by collagen lattice retarction, of single UVA-irradiated fibroblast was found. On the other hand, repeated UVA irradiation reduced expressions of type I procollagen and fibronectin, while increased expression of MMP-1 of fibroblasts. The contractile capacity of repeated UVA-irradiated fibroblasts also reduced. Therefore, repeated UVA-irradiated fibroblasts exhibited malfunctions as found in photoaged skin.
      PubDate: 2017-07-25T02:41:04.109557-05:
      DOI: 10.1111/php.12801
       
  • A Topical Zinc Ionophore Blocks Tumorigenic Progression in UV-exposed
           SKH-1 High-risk Mouse Skin
    • Authors: Rebecca Justiniano; Jessica Perer, Anh Hua, Mohammad Fazel, Andrea Krajisnik, Christopher M. Cabello, Georg T. Wondrak
      Pages: 1472 - 1482
      Abstract: Nonmelanoma skin cancer (NMSC) is the most common malignancy in the United States representing a considerable public health burden. Pharmacological suppression of skin photocarcinogenesis has shown promise in preclinical and clinical studies, but more efficacious photochemopreventive agents are needed. Here, we tested feasibility of harnessing pharmacological disruption of intracellular zinc homeostasis for photochemoprevention in vitro and in vivo. Employing the zinc ionophore and FDA-approved microbicidal agent zinc pyrithione (ZnPT), used worldwide in over-the-counter (OTC) topical consumer products, we first demonstrated feasibility of achieving ZnPT-based intracellular Zn2+ overload in cultured malignant keratinocytes (HaCaT-ras II-4; SCC-25) employing membrane-permeable fluorescent probes. Zinc overload was accompanied by induction of intracellular oxidative stress, associated with mitochondrial superoxide release as substantiated by MitoSOX Red™ fluorescence microscopy. ZnPT-induced cell death observable in malignant keratinocytes was preceded by induction of metal (MT2A), proteotoxic (HSPA6, HSPA1A, DDIT3, HMOX1) and genotoxic stress response (GADD45A, XRCC2) gene expression at the mRNA and protein levels. Comet analysis revealed introduction of formamidopyrimidine-DNA glycosylase (Fpg)-sensitive oxidative DNA lesions. In a photocarcinogenesis model (UV-exposed SKH-1 high-risk mouse skin), topical ZnPT administration post-UV caused epidermal zinc overload and stress response gene expression with pronounced blockade of tumorigenesis. Taken together, these data suggest feasibility of repurposing a topical OTC drug for zinc-directed photochemoprevention of solar UV-induced NMSC.Topical application of zinc pyrithione suppresses carcinogenesis in UV-induced high-risk SKH-1 mice.
      PubDate: 2017-07-21T13:51:04.996072-05:
      DOI: 10.1111/php.12794
       
  • Early Life UV and Risk of Basal and Squamous Cell Carcinoma in New South
           Wales, Australia
    • Authors: Anne Kricker; Marianne Weber, Freddy Sitas, Emily Banks, Bayzidur Rahman, Chris Goumas, Ahsanul Kabir, Verity S. Hodgkinson, Cathelijne H. Kemenade, Tim Waterboer, Bruce K. Armstrong
      Pages: 1483 - 1491
      Abstract: Sun exposure is the main cause of squamous (SCC) and basal cell carcinoma (BCC) although pattern and amount differ by cancer type, and sun sensitivity is the major host risk factor. Our study investigated risk factors and residential ambient UV in a population-based sample of Australian 45 and Up Study participants: 916 BCC cases, 433 SCC cases, 1224 controls. Unconditional logistic regression models adjusting for key covariates demonstrated 60% increased BCC risk and two-fold increased SCC risk with sun sensitivity, and three- and four-fold increased risk, respectively, with solar keratoses. BCC but not SCC risk increased with higher early-life residential UV in all participants (odds ratio (OR) = 1.54; 95% CI 1.22–1.96 for intermediate; OR = 1.31; 95% CI 1.03–1.68 for high UV at birthplace) and similarly in Australian-born participants (P-values < 0.05). Risk of SCC but not BCC increased with long-term cumulative sun exposure assessed by self-reported outdoor work (OR 1.74, 95% CI 1.21–2.49). In conclusion, sun sensitivity is important for both cancers, early-life UV but not cumulative UV appears to increase BCC risk, the former an apparently novel finding, and SCC risk appears only to be related to long-term cumulative sun exposure.Sun exposure is the main cause of squamous (SCC) and basal cell carcinoma (BCC) although role of pattern and amount differ by cancer type. This study of residential ambient UV in a high-UV environment shows risk of BCC but not SCC increased with higher early-life ambient UV by about two-fold for intermediate UV levels at birth and to the age of 15 years. Neither cumulative UV nor long-term outdoor work increased risk of BCC; the latter increased SCC risk. Our results reinforce the need for ongoing sun protection programs, especially in early life and for sun-sensitive people.
      PubDate: 2017-09-04T13:30:47.399382-05:
      DOI: 10.1111/php.12807
       
  • Various LED Wavelengths Affected Myofiber Development and Satellite Cell
           Proliferation of Chick Embryos via the IGF-1 Signaling Pathway
    • Authors: Yao Wang; Xinjie Bai, Zixu Wang, Jing Cao, Yulan Dong, Yanjun Dong, Yaoxing Chen
      Pages: 1492 - 1501
      Abstract: An effect of monochromatic light illumination on muscle mass has been discovered in chickens; however, its effect on the development of embryonic muscle remains unclear. Our previous studies demonstrated that monochromatic green light promoted satellite cell proliferation and muscle growth in posthatching broilers. In this study, we investigated the effects and mechanisms of monochromatic light exposure on muscle development in late embryogenesis. Seven hundred and fifty fertile broiler eggs were randomly assigned to blue (B-group), green (G-group), red (R-group), white (W-group) lights or darkness (D-group) throughout the incubation period. The muscle weight and fiber size were highest in the G-group compared to the other groups during embryonic days (E) 17 to E20. The proliferation of satellite cells isolated from the G-group was highest, and in vivo green light remarkably increased the number of proliferating cell nuclear antigen (PCNA)-positive cells in skeletal muscle. Meanwhile, plasma IGF-1 was higher (15.5–16.2%) in the G-group than that in D- and R-groups, and the satellite cells isolated from the G-group had a more sensitive response to IGF-1. These findings demonstrate green monochromatic photobiomodulation promoted the muscle growth and satellite cell proliferation was related to the IGF-1 signaling pathway in late embryogenesis.Monochromatic light can penetrate the eggshell and affected IGF-1 secretion in chicks during incubation period. Green monochromatic photobiomodulation promoted the muscle growth, and satellite cell proliferation was related to the IGF-1 signaling pathway in late embryogenesis.
      PubDate: 2017-09-04T13:32:00.955603-05:
      DOI: 10.1111/php.12806
       
  • Effects of Combined Lysosomal and Mitochondrial Photodamage in a
           Non-small-Cell Lung Cancer Cell Line: The Role of Paraptosis
    • Authors: David Kessel; John J. Reiners
      Pages: 1502 - 1508
      Abstract: We previously reported that a low level of lysosomal photodamage potentiated the phototoxic effect of subsequent mitochondrial photodamage mediated by the benzoporphyrin derivative (BPD) in murine hepatoma 1c1c7 cells. This was attributed to release of Ca2+ from damaged lysosomes and a calpain-mediated conversion of the autophagy-related protein ATG5 to a pro-apoptotic fragment. We now report a comparison of these results with those obtained with the human non-small-cell lung cancer A549 cell line. A549 cells contained lower levels of ATG5 and were less responsive than 1c1c7 cultures to the PDT combination. A rapid appearance of caspase 3/7 activation together with formation of condensed chromatin indicated initiation of apoptosis in both cell lines, but to a lesser extent in A549 cultures. Both cell lines became highly vacuolated within 16 h of combination PDT or an equivalent phototoxic dose from BPD alone. The vacuole periphery was labeled with a fluorescent probe for the endoplasmic reticulum (ER), and vacuole formation was prevented by presence of the protein synthesis inhibitor cycloheximide. These effects are characteristics of a caspase-independent death mode termed paraptosis previously associated with ER stress. These studies suggest that paraptosis may be a more frequent outcome of PDT than has hitherto been realized.Morphology of cell death in A549 (NSCLC) cells during apoptosis (left) and paraptosis (right).
      PubDate: 2017-09-04T13:31:19.112163-05:
      DOI: 10.1111/php.12805
       
  • Measurement of UV Emission from a Diffusing Optical Fiber Using
           Radiochromic Film
    • Authors: David Welch; Henry M. Spotnitz, David J. Brenner
      Pages: 1509 - 1512
      Abstract: Analysis of the emission pattern from optical diffuser tips is vital to their usage in biomedical applications, especially as they find growing functionality beyond established phototherapy techniques. The use of ultraviolet radiation with diffuser tips increases the need to accurately characterize these devices, both for effective application and to avoid potentially dangerous exposure conditions. This study presents a new method to capture the diffusion pattern at a high resolution through the use of radiochromic film. The film is positioned in a cylinder around the diffuser, light is emitted from the diffuser onto the film and the film expresses a color change relative to the exposure amount. The resulting emission map shows the distribution of power from the diffuser in all direction. This method, which is both quick and inexpensive, generates high-resolution data much simpler than previously published works which required precise goniometric positioning.Analysis of the emission pattern from optical diffuser tips is vital to their usage in biomedical applications. The use of ultraviolet radiation with diffuser tips increases the need to accurately characterize these devices, both for effective application and to avoid potentially dangerous exposure conditions. This work presents a new method to evaluate the ultraviolet light diffusion pattern at a high resolution using radiochromic film positioned around the diffusing tip.
      PubDate: 2017-07-21T13:50:49.774908-05:
      DOI: 10.1111/php.12798
       
  • Clothing Protection from Ultraviolet Radiation: A New Method for
           Assessment
    • Authors: Ryan Gage; William Leung, James Stanley, Anthony Reeder, Michelle Barr, Tim Chambers, Moira Smith, Louise Signal
      Pages: 1513 - 1518
      Abstract: Clothing modifies ultraviolet radiation (UVR) exposure from the sun and has an impact on skin cancer risk and the endogenous synthesis of vitamin D. There is no standardized method available for assessing body surface area (BSA) covered by clothing, which limits generalizability between study findings. We calculated the body cover provided by 38 clothing items using diagrams of BSA, adjusting the values to account for differences in BSA by age. Diagrams displaying each clothing item were developed and incorporated into a coverage assessment procedure (CAP). Five assessors used the CAP and Lund & Browder chart, an existing method for estimating BSA, to calculate the clothing coverage of an image sample of 100 schoolchildren. Values of clothing coverage, inter-rater reliability and assessment time were compared between CAP and Lund & Browder methods. Both methods had excellent inter-rater reliability (>0.90) and returned comparable results, although the CAP method was significantly faster in determining a person's clothing coverage. On balance, the CAP method appears to be a feasible method for calculating clothing coverage. Its use could improve comparability between sun-safety studies and aid in quantifying the health effects of UVR exposure.Clothing is an important modifier of UVR exposure. This article compared two methods for assessing clothing coverage at the population level (the coverage assessment procedure (CAP) and the Lund & Browder Chart). The findings suggest that the CAP could be an efficient tool for calculating clothing coverage. Its use could improve comparability between sun-safety studies focused on clothing.
      PubDate: 2017-07-25T02:40:37.161976-05:
      DOI: 10.1111/php.12803
       
  • NAD(P)H and Flavin Autofluorescence Correlation with ATP in Rat Livers
           with Different Metabolic Steady-State Conditions
    • Authors: Anna C. Croce; Andrea Ferrigno, Laura G. Di Pasqua, Clarissa Berardo, Giovanni Bottiroli, Mariapia Vairetti
      Pages: 1519 - 1524
      Abstract: The monitoring of NAD(P)H and flavin autofluorescence (AF) is at the basis of numerous investigations on energy metabolism. Nevertheless, the ability of these AF biomarkers to accurately represent the energy currency, ATP, is poorly explored. Here, we focused on the AF/ATP correlation in lean and fatty livers with different steady-state metabolic conditions, achieved after organ isolation, preservation and recovery, in a likely dependence on both liver intrinsic metabolic features and externally induced perturbations. Within these eventual, various conditions, a significant correlation was detected between liver NAD(P)H and flavin AF, measured via fiber-optic probe, and biochemical ATP data, strengthening AF as biomarker of energy metabolism in steady-state conditions for wide-ranging experimental and diagnostic applications.The autofluorescence of NAD(P)H and flavins directly reflects the different levels of intratissue energy, achieved by lean and fatty liver models when recovering from previous isolation and external perturbations induced by different conditions of preservation.
      PubDate: 2017-09-04T13:30:54.227378-05:
      DOI: 10.1111/php.12804
       
  • Interactions Between phyB and PIF Proteins Alter Thermal Reversion
           Reactions in vitro
    • Authors: Robert W. Smith; Britta Helwig, Adrie H. Westphal, Eran Pel, Jan Willem Borst, Christian Fleck
      Pages: 1525 - 1531
      Abstract: The dynamic behavior of the plant red/far-red light photoreceptor phytochrome B (phyB) has been elucidated in natural and synthetic systems. Red light switches phyB from the inactive Pr state to the active Pfr state, a process that is reversed by far-red light. Alongside light signals, phyB activity is constrained by thermal reversion (that is prominent in the dark) and protein–protein interactions between phyB, other phytochrome molecules, and, among others, PHYTOCHROME INTERACTING FACTORs (PIFs). Requirements for phyB-PIF association have been well studied and are central to light-regulated synthetic tools. However, it is unknown whether PIF interactions influence transitions of phyB between different conformers. Here, we show that the in vitro thermal reversion of phyB involves multiple reactions. Thermal reversion of phyB in vitro is inhibited by PIF6, and this effect is observed at all temperatures tested. We analyzed our experimental data using a mathematical model containing multiple Pfr conformers, in accordance with previous findings. Remarkably, each Pfr conformer is differentially regulated by PIF6 and temperature. As a result, we speculate that in vivo phytochrome signaling networks may require similar levels of complexity to fine-tune responses to the external environment.The red/far-red light plant photoreceptor phytochrome B (phyB) interacts with PHYTOCHROME INTERACTING FACTOR (PIF) proteins to regulate downstream responses in both natural and synthetic systems. Here, we show that the interaction with PIF proteins inhibits the thermal reversion of phyB from the active Pfr to inactive Pr state across the ambient temperature range. In combination with mathematical modelling, we determine that two forms of Pfr exist, that they have different thermal relaxation rates, and that they are differentially regulated by PIFs. Further unknown biological modifications to the phyB-PIF complexes ultimately prevent thermal reversion of phyB.
      PubDate: 2017-07-21T13:50:34.430448-05:
      DOI: 10.1111/php.12793
       
  • A Heartfelt Thanks to the Editors and Contributors of Special Issue 93:3
    • Authors: Wolfgang Gärtner
      Pages: 1532 - 1533
      PubDate: 2017-11-10T13:55:42.269341-05:
      DOI: 10.1111/php.12844
       
 
 
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