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CHEMISTRY (598 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 10)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 38)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 18)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 24)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 252)
ACS Photonics     Full-text available via subscription   (Followers: 12)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 23)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chimica Slovenica     Open Access  
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 51)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 57)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 15)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 21)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 66)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 15)
American Journal of Chemistry     Open Access   (Followers: 27)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Analyst     Full-text available via subscription   (Followers: 39)
Angewandte Chemie     Hybrid Journal   (Followers: 179)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 229)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 16)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 326)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 120)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 85)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 3)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 5)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 68)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 7)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 8)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 15)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 70)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 25)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 21)
Chemical Reviews     Full-text available via subscription   (Followers: 184)
Chemical Science     Open Access   (Followers: 22)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 146)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 20)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 42)
Chemistry of Materials     Full-text available via subscription   (Followers: 246)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 10)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 19)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 18)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 64)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 3)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  

        1 2 3 | Last

Journal Cover Bulletin of the Korean Chemical Society
  [SJR: 0.297]   [H-I: 44]   [1 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Online) 1229-5949
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Structural and Photoluminescent Properties of Near-Infrared Emissive
    • Authors: Young-Inn Kim; Seong-Jae Yun, Daeyoung Kim, Sung Kwon Kang
      PubDate: 2018-01-08T20:10:43.067077-05:
      DOI: 10.1002/bkcs.11357
  • Conformers of Zwitterionic Glycine in Aqueous Phase
    • Authors: Manik Kumer Ghosh; Tae Hoon Choi, Cheol Ho Choi
      Abstract: Zwitterionic glycine was investigated for its major conformers and their isomerizations in aqueous phase by QM/MM-MD. The rotameric barrier of zwitterionic glycine along C−C bond is approximately 2 kcal/mol higher than that of non-ionized one. It can be attributed to the strong electrostatic effects of zwitterion, which attracts water solvents more tightly. Unlike the previous quantum mechanical calculations, our QM/MM-MD found that only the gauche conformer as stable minima along the C−N bond rotation. Overall, the preferred conformers in real solution are different from those found with limited clusters, necessitating the use of QM/MM-MD.
      PubDate: 2018-01-08T03:26:19.186318-05:
      DOI: 10.1002/bkcs.11372
  • Mechanisms of the Binding/Dissociation Acceleration of the Target–Guide
           Interaction by Thermus thermophilus Argonaute
    • Authors: Seung-Ryoung Jung; Eunji Kim, Soochul Shin, Ji-Joon Song, Sungchul Hohng
      Abstract: Prokaryotic Argonaute facilitates the target recognition process by the guide strand via a still unknown mechanism. Using single-molecule fluorescence resonance energy transfer and systematic mutagenesis of Thermus thermophilus Argonaute and guide-target base pairing, we study the kinetic roles of various structural features of guide strand in the prokaryotic Argonaute. We reveal that the 5′-end anchoring of the guide strand, and the sequence complementarity in the seed- and mid-regions greatly accelerate the target binding, and that this acceleration is due to the reduction of the entropic barrier of the binding process. Our data further suggest that the dynamic anchoring of the guide strand to the PAZ domain, which is coupled to target dissociation, does not accompany the partial unwinding of the guide-target duplex.
      PubDate: 2018-01-08T03:16:20.642078-05:
      DOI: 10.1002/bkcs.11362
  • High-Level Expression and Purification of Tag-free Peptides Containing
           Multiple Disulfide Bond in Pichia pastoris
    • Authors: Yunqi Ma; So-Sun Kim, Dong-Geon Kwag, Seo-Hyun Kim, Min-Seob Kim, Seung-Ho Ryu, Dong-Hoon Lee, Jae-Hyeong So, Bo-Hye Nam, Yong-Ok Kim, Cheul-Min An, Jang-Su Park
      Abstract: Eukaryotic expression systems are used widely and have the advantages of protein processing, proteolytic cleavage, disulfide bond formation, and posttranslational modification in contrast to the prokaryotic expression system. In the present study, peptide gene (olive flounder beta-defensin or hepcidin) was inserted into the vector of pPIC9K, which involved the secretion signal and promoter AOX1. The colonies with high copy numbers of the target gene for high-level expression were selected by G418. Approximately 30 mg/L for beta-defensin and 25 mg/L for hepcidin was obtained from the culture medium supernatant. An ammonium sulfate salting-out method was used for purification; this one-step purification simplified the procedures, and the purification effect was good in terms of the purity and yield. The proteins from yeast itself could be isolated easily using the ammonium sulfate salting-out method.
      PubDate: 2018-01-08T03:15:58.06849-05:0
      DOI: 10.1002/bkcs.11369
  • Total Syntheses of Biologically Active Pterocarpan, Isoflavan, and
           Isoflavanone from Dalbergia oliveri
    • Authors: Dileep Kumar Singh; Jinwoo Kim, Jong-Hyuk Sung, Ikyon Kim
      Abstract: Biological screening of the natural products from Dalbergia oliveri identified that (6aR,11aR)-3,8-dihydroxy-9-methoxypterocarpan and (3R)-7,2′-dihydroxy-4′,5′-dimethoxyisoflavanone significantly increased the proliferation of dermal papilla cells and subcutaneous injection of these compounds induced the anagen of hair cycle in animal models. These interesting biological activities led us to design a practical synthetic route to these natural products for further pharmacological evaluation. Here we report the first total syntheses of naturally occurring pterocarpan ((6aR,11aR)-3,8-dihydroxy-9-methoxypterocarpan), isoflavan ((3R)-5′-methoxyvestitol), and isoflavanone ((3R)-7,2′-dihydroxy-4′,5′-dimethoxyisoflavanone) in a racemic form. A mild ZnCl2-mediated [3 + 2] annulation method was utilized with chromenes and 2-methoxy-1,4-benzoquinone to construct a pterocarpan framework in a one-pot manner. O-methylation and reductive cleavage of the benzylic C─O bond afforded 5′-methoxyvestitol, which was transformed to isoflavanone, 7,2′-dihydroxy-4′,5′-dimethoxyisoflavanone, via a three-step sequence including DDQ-mediated benzylic oxidation.
      PubDate: 2018-01-05T01:36:01.719873-05:
      DOI: 10.1002/bkcs.11375
  • A Novel Anthracene–Imidazole-based Fluorescent “Turn-on”
           Chemosensor for Fe3+
    • Authors: Kyoung-Lyong An; Seung-Rim Shin, Yujin Oh, Hwalkee Park, Kun Jun
      Abstract: Proposed binding mode of sensor with Fe3+.
      PubDate: 2018-01-04T02:50:58.115765-05:
      DOI: 10.1002/bkcs.11353
  • Quantification of Folic Acid in Human Serum Using Isotope Dilution
           Ultra-High-Pressure Liquid Chromatography/Mass Spectrometry
    • Authors: Seok-Won Hyung; Joonhee Lee, Hye-Young Seo, Byungjoo Kim
      Abstract: Analytical method for an accurate determination of folic acid in human serum has been established using isotope dilution ultra-high-pressure liquid chromatography/mass spectrometry (ID-UPLC/MS). Sample extract was prepared from 0.5 mL of human serum spiked with 13C5-folic acid solution and then LC–MS/MS experiment was performed on multiple reaction monitoring mode for 20 min. The method was tested for repeatability using homogeneous human serum and it showed good repeatability with relative standard deviation of 1.8%. Further evaluation was carried out through NIST SRM 1955 samples (level I, II, and III) and the measurement results were in good agreement with the certified values with good reproducibility over two periods. It was also revealed that the obtained relative expanded uncertainty was 12% which is much smaller than that of previously reported methods, indicating that this method is very reliable and accurate for determining the content of folic acid in human serum.
      PubDate: 2018-01-04T02:50:24.605387-05:
      DOI: 10.1002/bkcs.11356
  • Selective Detection of 2,4,6-Trinitrophenol Based on In Situ-generated
    • Authors: Anup Pandith; Hong-Seok Kim
      Abstract: Novel in situ-generated highly fluorescent chelated Zn2+–anthracene (Zn2+•P: 1:1) complex detected 2,4,6-trinitrophenol (TNP) more selectively by a “switch-off” response with a very high Stern–Volmer quenching constant (Ksv = 3.75 × 106 M−1) at a 1:2 stoichiometry in 80% aqueous DMSO. The selective quenching response that occurred with TNP is due to the effective destruction of the chelated complex by efficient protonation at secondary amines, which created an effective resonance energy transfer (RET) from the anthracene unit to the TNP. Formation of a stable P2+•(TNP)−2 ionic charge-transfer complex showed that the anthracene monomer band quenching resulted from efficient RET, accompanied by synergistic multiple hydrogen bonding, electron-rich–electron-deficient πAn–πTNP interactions, and columbic interactions. An application was demonstrated using the biocompatible ensemble-coated hydrogel for ultraviolet-assisted naked eye sensing, and its sensing mechanism was postulated. The lowest detection limit for TNP was 3.01 × 10−10 M in 80% aqueous DMSO.
      PubDate: 2018-01-04T02:47:20.574513-05:
      DOI: 10.1002/bkcs.11286
  • Synthesis of FTY720 (Fingolimod) Derivatives Containing Serine Structure
    • Authors: Yoon Sin Oh; Taeho Lee, Sang Mi Shin, Jitendra Shrestha, Doohyun Lee, Eun-Young Park, Dong Jae Baek
      PubDate: 2018-01-03T23:21:24.890072-05:
      DOI: 10.1002/bkcs.11370
  • Enantioselective Synthesis of the Northwestern Fragment of Tausalarin C
    • Authors: Hyun Woo Joo; Byung Soo Lee, Yu Mi Pyun, Duck-Hyung Lee
      PubDate: 2018-01-03T07:39:10.711687-05:
      DOI: 10.1002/bkcs.11339
  • DQAsomes Nanoparticles Promote Osteogenic Differentiation of Human
           Adipose-derived Mesenchymal Stem Cells
    • Authors: Yoonhee Bae; Min Kyo Jung, Ji Young Mun, Sudipta Mallick, Su Jeong Song, Dong Min Kim, Kyung Soo Ko, Jin Han, Joon Sig Choi
      Abstract: Mesenchymal stem cells (MSCs) can self-renew and differentiate into multiple cell types. The delivery of drugs to MSCs is an important tool in the emerging fields of tissue regeneration and engineering. In this study, we determined the anticancer efficiency of DQAsomes, which displayed affinity toward human adipose-derived mesenchymal stem cells (AD-MSCs). Cytotoxicity assays were conducted to examine human AD-MSCs. We also evaluated the cellular effects of human AD-MSCs treated with DQAsomes by cell cycle distribution analysis, annexin-V propidium iodide staining, and H2DCFDA and found that DQAsomes promoted the differentiation of AD-MSCs into osteoblast cells. Furthermore, flow cytometry analysis revealed that human AD-MSCs treated with DQAsomes maintained the phenotypic characteristics of human AD-MSCs. We demonstrated that DQAsomes can be used in tissue engineering and have clinical relevance as effective drug and protein delivery systems.
      PubDate: 2018-01-03T07:39:07.979831-05:
      DOI: 10.1002/bkcs.11355
  • Antimetastatic Activity of Gallic Acid-conjugated Chitosan against
           Pulmonary Metastasis of Colon Carcinoma Cells
    • Authors: Hye Lim Lee; Cheol Woong Choi, Jungsoo Kim, Byungyoul Cha, Jae Woon Nah, Jeong Sup Hong, Sung Chul Hwang, Young-IL Jeong, Dae Hwan Kang
      Abstract: We synthesized gallic acid (GA)-conjugated chitosan (abbreviated as chitogallate) to study its antitumor activity against CT26 mouse colorectal carcinoma cells. GA was conjugated with chitosan by aid of water-soluble carbodiimide. Chitogallate nanoparticles were prepared by dialysis method, and these nanoparticles have spherical shapes with sizes ranged about 70–250 nm. Chitogallate nanoparticles have superior antioxidants activities as well as GA itself. At cytotoxicity study, GA showed dose-dependent cytotoxicities against CCD986sk cells and CT26 cells while chitogallate nanoparticles were not significantly affected to the viability of cells. In Matrigel invasion assay, chitogallate nanoparticles have superior anti-invasive capacity against cancer cells as well as GA itself, i.e., invasiveness of CT26 cells was decreased according to GA contents in chitogallate nanoparticles. Furthermore, gelatin zymography also showed that chitogallate nanoparticles having higher substitution degree of GA decreased matrix metalloproteinase-2 activity. Chitogallate nanoparticles efficiently inhibited pulmonary metastasis of CT26 cells in animal pulmonary metastasis model. We prepared chitogallate nanoparticles for application as an anti-invasive agent. Chitogallate nanoparticles were less toxic than GA itself and have superior anti-invasive/antimetastatic activity. We suggest that chitogallate nanoparticles are promising candidate for inhibition of tumor invasion/metastasis.Gallic acid-conjugated chitosan (chitogallate) conjugates were synthesized as an anticarcinogenic agent to inhibit invasion and migration of cancer cells. Chitogallate nanoparticles were properly inhibited invasion and matrix metalloproteinase (MMP)-2 activity of CT26 cells. Chitogallate nanoparticles also showed higher antimetastatic activity than GA itself.
      PubDate: 2017-12-28T23:31:48.961997-05:
      DOI: 10.1002/bkcs.11351
  • CO2 Capture on a Novel Porous Silicate Material from Coal Gangue:
           Equilibrium, Kinetic, and Thermodynamic Studies
    • Authors: Yajun Gao; Hong Du, Yu Wu, Kai Liu, Jianbin Zhang
      Abstract: The adsorption of CO2 on a novel porous silicate material (PSM) from coal gangue at T = (288.15, 303.15, and 318.15) K was thoroughly characterized, and the experimental results showed that the adsorption capacity increased with the increasing pressures. Furthermore, the isotherm data were well fitted to Double–Langmuir model, and the adsorption process was found to be exothermic in nature with a decrease in entropy. Meanwhile, thermodynamic results also showed that the adsorption occurred via a spontaneous and enthalpy driven process and controlled by physisorption. In addition, the adsorption performance was still stable after 10 times adsorption—desorption cycles, which indicated that the PSM had a positive regeneration performance.Thermodynamic plots for CO2 adsorption on adsorbent.
      PubDate: 2017-12-28T10:15:59.309414-05:
      DOI: 10.1002/bkcs.11364
  • Gold Nanoparticle-based Novel Biosensors for Detecting Glycated Hemoglobin
    • Authors: Jiwon Kwak; Hyeoun Ji Park, Soo Suk Lee
      Abstract: We report here on novel biosensors for the highly sensitive and specific enzymatic analysis of glycated hemoglobin (HbA1c), which we measured primarily to identify three-month average plasma glucose concentrations. Hydrogen peroxide (H2O2) was generated in this enzymatic measuring of glycated hemoglobin from oxidative cleavage of fructosyl valine by fructosyl amino acid oxidase, and we then used the generated hydrogen peroxide as a reducing agent of gold (III) ion to synthesize gold (0) as a nanoparticle. We were able to measure the gold nanoparticles obtained from this novel approach using colorimetry under a UV–VIS spectrophotometer. For this colorimetric detection, we analyzed 96-well plates for glycated hemoglobin, and this system worked very well, with a detection limit of 0.142% and coefficient of variation below 10%. Finally, this method can measure glycated hemoglobin in patients with diabetes.We have developed colorimetric biosensors combined with size enhancement of AuNPs by enzymatically generated hydrogen peroxide detected HbA1c in a sensitive, rapid, and reproducible manner.
      PubDate: 2017-12-28T00:10:55.838584-05:
      DOI: 10.1002/bkcs.11360
  • Fragmentation Pathways of Tadalafil and Its Analogues in Electrospray
           Ionization Tandem Mass Spectrometry
    • Authors: Jung-min Lee; Jongki Hong, Han Bin Oh, Bongjin Moon
      Abstract: Tadalafil is one of the most potent inhibitors against Type V phosphodiesterase (PDE-5) along with sildenafil and vardenafil exhibiting high efficacy in treatment for erectile dysfunction (ED). Due to their high ED efficacy, many illegal attempts to add their derivatives in dietary supplements have been made and LC-ESI-MS/MS has proven to be a powerful tool to expose such malfeasance. In contrast to sildenafil or vardenafil-based analogues, tadalafil analogues have limited structural variation mainly localized at N2-position to maintain their pharmacological activity. Therefore, it is probable that even the illegal yet unknown tadalafil analogues have similar structural aspect. After careful examination of ESI-MS/MS spectra of tadalafil and its eight analogues, a detailed fragmentation mechanism with three major pathways was identified. Based on this mechanism, four distinct common ions [m/z 135 (C1), m/z 262 (C2), m/z 197 (C3), m/z 169 (C4)] and additional identifier ions (I1~I7) that reflect the structural variations were assigned.
      PubDate: 2017-12-28T00:06:13.748938-05:
      DOI: 10.1002/bkcs.11365
  • Synthesis of 1,2,3-Triazole and Pyrazole Analogues as Bioisosteres of
    • Authors: Wei Sun; Taek-Soo Kim, Nam Song Choi, Seung-Yong Seo
      Abstract: The designed 1,2,3-triazole and pyrazole analogues of neolignans.
      PubDate: 2017-12-27T03:25:13.449073-05:
      DOI: 10.1002/bkcs.11352
  • Thiourea-catalyzed Oxidative Coupling Reaction of N-Phenyl
           Tetrahydroisoquinoline with β-Keto Acids
    • Authors: Hyun Jung Jeong; Yong Hwan Kim, Dae Young Kim
      PubDate: 2017-12-27T03:25:13.027906-05:
      DOI: 10.1002/bkcs.11354
  • Synthesis of 4-Anilinoquinazoline-Derivative Dual Kinase Inhibitors
           Targeting EGFR and VEGFR-2
    • Authors: Keuk Chan Bang; Tae Hun Song, Young Jin Park, Jong Soo Lee, Seungah Jun, Seung Hyun Jung, Young-Jin Chun, Ha Hyung Kim
      Abstract: .
      PubDate: 2017-12-27T03:25:12.686405-05:
      DOI: 10.1002/bkcs.11348
  • Highly Stereoselective Reactions of
           2-(t-Butyl)dimethylsilyl-3,3-difluoro-1-phenylprop-2-en-1-one with
    • Authors: Ye Rim Jeong; Hyun Gyu Ryu, Sung Yong Won, In Howa Jeong
      PubDate: 2017-12-27T03:16:03.532216-05:
      DOI: 10.1002/bkcs.11332
  • A Metal-Free, Non-Enzymatic Electrochemical Glucose Sensor with a
           de-Bundled Single-Walled Carbon Nanotube-Modified Electrode
    • Authors: Dinakaran Thirumalai; Devaraju Subramani, Bosung Shin, Hyun-jong Paik, Seung-Cheol Chang
      Abstract: A new metal-free, non-enzymatic electrochemical sensor system for the detection of glucose was developed in this study. The developed sensor uses a de-bundled single-walled carbon nanotube (SWCNT)-modified glassy carbon electrode (GCE). SWCNTs were de-bundled in aqueous solution by adding a synthesized polymer dispersant, sulfonated poly(ether sulfone). The de-bundled SWCNTs showed two significant characteristics: (1) improvement of the aspect ratio and dispersibility in aqueous solution and (2) suitability for use as a selective and sensitive sensing element in non-enzymatic glucose sensors. The experimental results clearly demonstrated that the SWCNTs/GCE possesses high electro-catalytic activity and efficient sensitivity with a stable and faster amperometric response production. Furthermore, interference by ascorbic acid, acetaminophen, uric acid, and dopamine is effectively avoided. Therefore, the proposed approach is favorable for the design and development of non-enzymatic glucose sensors.
      PubDate: 2017-12-26T02:05:33.071681-05:
      DOI: 10.1002/bkcs.11358
  • Uniform Surface Characteristics in Sequentially Polymerized Polyurea Films
    • Authors: Ui-Jin Choi; Hyein Kim, Yi-Seul Park, Jin Seok Lee
      Abstract: We successfully fabricated uniformly aligned polyurea thin films using molecular layer deposition (MLD) technique. By measuring the film thickness as a functional of the number of cycles, we confirmed the linear growth behavior of the polyurea MLD film. We also fabricated a spin-coated polyurea films after synthesis of the polyurea polymer in solution, and compared their roughness and surface potential with the prepared MLD film. The polyurea MLD film had a low root-mean square value and homogeneous surface potentials, whereas the spin-coated film had very rough surface and a highly variable surface potential. We believe that our results will contribute to performance improvement of polymer-based electrical devices and provide greater insight into the fabrication of uniformly aligned polymer thin films.
      PubDate: 2017-12-21T07:51:24.437897-05:
      DOI: 10.1002/bkcs.11344
  • Determination of Fenpyroximate from Four Types of Honey by Liquid
           Chromatography/Tandem Mass Spectrometry
    • Authors: Jin Mun Kim; Seung-Woon Myung
      Abstract: Fenpyroximate is an acaricide used to control phytophagous mites in beekeeping farms, and is used to regulate residual amounts in honey in European Union countries. An effective and accurate sample preparation method was established for a liquid chromatograph-mass spectrometer/mass spectrometer (LC–MS/MS) analysis of four types of honey (acacia honey, wild honey, manuka, and chestnut honey). Experiments were carried out to determine the optimal values of parameters such as sample pH, type of solid-phase cartridge, type and volume of extraction solvent, loading sample volume, type and volume of eluent for effective sample extraction, purification, and concentration. Chromatographic separation was performed using a C18 (3.0 mm i.d. × 50 mm length, 2.7 μm particle size) column under isocratic conditions of water and acetonitrile (30:70). The optimized parameters for the extraction of fenpyroximate are as follows: sample pH, 7; type of sorbent solid phase, aminopropyl; volume of extraction solvent, 20 mL; volume of loading sample, 2 mL; eluent, dichloromethane/n-hexane (65/35%, v/v); eluent volume, 6 mL. The limits of detection and quantitation for spiked honey samples were 1.56 and 5.00 μg/kg, respectively. Linear correlation coefficient (r) obtained from a concentration range 5.00–50.0 μg/kg was 0.9914–0.9977, while the accuracy and precision were 87.99–119.06% and 0.68–14.71% (RSD), respectively. Residue monitoring of fenpyroximate was also performed on 30 commercially available honeys using established methods.
      PubDate: 2017-12-21T06:55:39.848507-05:
      DOI: 10.1002/bkcs.11346
  • Synthesis of Peptide Nucleic Acid Dimer Containing Modified Cytosine
    • Authors: Yeong Deok Lee; Kyung Sun Yoon, Keun Ho Chun
      PubDate: 2017-12-21T06:54:01.281759-05:
      DOI: 10.1002/bkcs.11340
  • Solution-based Sulfur-Polymer Coating on Nanofibrillar Films for
           Immobilization of Aqueous Mercury Ions
    • Authors: Jaehyuk Lee; Seyeong Lee, Jihee Kim, Zahid Hanif, Seunghee Han, Sukwon Hong, Myung-Han Yoon
      Abstract: Herein, we report the solution-based method for coating sulfur polymers on various substrate materials. First, sulfur polymers were synthesized by reacting elemental sulfur and 1,3-diisopropenylbenzene and dissolved in various organic solvents to search for solvents with good solubility. Next, the trend in film thickness of sulfur-polymer coating was systematically examined using the sulfur-polymer solutions in dichlorobenzene (DCB) and various materials with different surface energy. The nanofibrillar film made of the poly(vinyl alcohol) and poly(acrylic acid) (PVA-PAA) blend exhibited the most uniform/conformal deposition of sulfur polymer via dipping-coating, indicating that the DCB solution is most suitable for the well-controlled deposition of sulfur polymer on nanostructured materials with higher surface energy than 40 mN/m. Finally, the resultant sulfur polymer-coated nanofibrillar film showed high mercury ion uptake capacity (26 mg/g with 50 ppm Hg solution) even with a small amount of sulfur-based adsorbent (20 mg) loading on the film (40 mg). Our study suggests that the sulfur polymer solution can introduce the crucial properties of elemental sulfur on the surface of any conventional materials even with mechanical flexibility and nano/microscale structural complexity.
      PubDate: 2017-12-18T08:20:41.026761-05:
      DOI: 10.1002/bkcs.11350
  • In Situ Formation of Pt–Au Nanoparticles on Magnetic Composites
           Carriers: Tuning Catalytic Activity by Incorporation of Different Metal
    • Authors: Zewu Zhang; Qiong Wu, Xiaohai Bu, Zusheng Hang, Zhangzhong Wang, Qikang Wang, Yuhang Ma
      Abstract: Supported Pt─Au bimetal nanocatalysts have been prepared by an in situ reduction method followed by calcination in air and reduction in H2 atmosphere. The catalysts exhibit a typical yolk-shell construction composed of a moveable magnetic Fe core and metal oxides shells decorated with Pt─Au nanoparticles. The structure of the bimetal nanocatalysts was characterized in detail by TEM, XRD, XPS, and N2 physical adsorption and the catalytic activity of the nanocatalysts was studied by the catalytic reduction of 4-nitrophenol to 4-nitrophenol. It is found that the bimetal nanocatalysts composed with the different metallic oxides (TiO2 and ZrO2) exhibited the comparable Pt─Au particles size (~10 nm). However, the content of Pt─Au nanoparticles was varied with the metallic oxides support. Pt─Au nanoparticles deposited uniformly on TiO2 with higher loadings, however the nanoparticles on ZrO2 exhibited remarkably lower content, which should be attributed to the abundant hydroxyl on TiO2 surface that served as the deposition site for Pt─Au nanoparticles. The result of the reduction reaction indicated that incorporation of TiO2 in the bimetal Pt─Au nanocatalyst could significantly improve the catalytic activity as compared with ZrO2 and m-SiO2. A possible mechanism was proposed to explain the synergistic effect in the supported Pt─Au bimetal nanocatalysts.Pt–Au nanoparticles supported on Fe@metallic oxides composites with efficient magnetic recycling were prepared by a facile in situ Sn2+ reduction method.
      PubDate: 2017-12-15T03:42:41.41631-05:0
      DOI: 10.1002/bkcs.11347
  • 1H NMR Based Metabolomics Studies of the Toxicity of Titanium Dioxide
           Nanoparticles in Zebrafish (Danio rerio)
    • Authors: Ganesan Raja; Siwon Kim, Dahye Yoon, Changshin Yoon, Suhkmann Kim
      Abstract: Titanium dioxide nanoparticles (TiO2-NPs) are widely used in foods, cosmetics, and pharmaceuticals. In the present study, male and female zebrafish (Danio rerio) were exposed to sub-lethal concentrations of TiO2-NPs dosed at 0.1 mg/L (low) and 5.0 mg/L (high), respectively. 1H–nuclear magnetic resonance (NMR) profiling combined with univariate and multivariate statistics was used to assess metabolic alterations in the TiO2-NP-treated fish. Purine metabolism—including the anabolism/catabolism of ATP, ADP, AMP, xanthine, and inosine—was significantly influenced, which may indicate some genotoxicity resulting from TiO2-NP exposure. Increasing the dose and duration of TiO2-NP exposure led to additional metabolic disturbances in glycerophospholipid metabolism and the Krebs cycle. Our findings demonstrate the potential applicability of using a metabolomics approach to determine underlying metabolic disturbances caused by TiO2-NPs.
      PubDate: 2017-12-14T06:11:17.100211-05:
      DOI: 10.1002/bkcs.11336
  • What Function Is Optimal for CCSD(T) Complete Basis Extrapolation for OH
           Stretching Potential of Water Molecules'
    • Authors: Mino Yang
      Abstract: A procedure to calculate the complete basis set limits of electronic energy of water molecules is developed based on two levels of extrapolation scheme. A three-point fitting scheme with the energies computed at the levels of basis function, aug-cc-pVXZ for X = 4–6, is employed to obtain accurate energies of a monomer and a dimer of water. Three extrapolation functions considered in this article are found to work excellently to give accurate Hartree–Fock (HF) energies of water molecules. However, the three functions give slightly different values up to 1–2 mHartree for the complete basis limit of electronic correlation energy. The best performing extrapolating function for the five-point fitting scheme with a larger set of basis functions for X = 2–6 has been determined aiming for the extrapolation from the lowest two levels of basis sets, double and triple zeta basis functions. For this purpose, an exponential function is suggested for HF energy while an exponential function with a square root exponent is suggested for electronic correlation energy. The optimal exponents of the two functions have been determined.
      PubDate: 2017-12-12T03:02:30.656335-05:
      DOI: 10.1002/bkcs.11341
  • Development of Transition-Metal-Free Carbon–Carbon and Carbon-Boron
           Bond-Forming Reactions by Utilizing 1,1-Bis[(Pinacolato)Boryl]Alkanes
    • Authors: Kyu Dong Kim; Jun Hee Lee
      PubDate: 2017-12-12T03:02:28.478347-05:
      DOI: 10.1002/bkcs.11343
  • Homoleptic Iridium(III) Compounds Bearing Bulky Bipyridine Ligand for
           Potential Application to Organic Light-emitting Diodes
    • Authors: Myeongbee Kim; Joohye Park, Hoonseok Oh, Yeonjin Ryu, Youngjin Kang
      Abstract: Two sky-blue phosphorescent iridium compounds, fac-tris(2′,6′-diisopropoxy-2,3′-bipyridinato)-N,C4)Ir(III) (1) and fac-tris(2′,6′-diisopropoxy-4-tert-butyl-2,3′-bipyridinato)-N,C4)Ir(III) (2), were synthesized by a one-pot reaction of a reactive Ir(I) compound with a corresponding bipyridine ligand, to investigate their photophysical and electrochemical properties for potential application to white organic light-emitting diodes (WOLEDs). Their structures were confirmed by varied spectroscopic methods. Results indicated that both compounds possess facial geometry. The absorption, emission, thermal stability, and electrochemical properties were also investigated systematically. The two compounds showed sky-blue emission with λmax = 462–463 nm; their photoluminescence quantum efficiencies relative to that of FIrpic were ~0.3–0.4. Compound 2 with a bulky substituent displayed the suppression of concentration quenching at high concentration, and its emission was less shifted to longer wavelengths compared to compound 1. Owing to the bulky substituent, the quantum efficiency of 2 is higher than that of its nonsubstituted counterpart. Therefore, the introduction of the bulky substituent in the ligand framework is an important strategy for developing high-efficiency blue phosphorescent materials. The two compounds developed in this study show high thermal and electrochemical stability, making them suitable candidates for OLED applications.
      PubDate: 2017-12-12T03:01:51.796924-05:
      DOI: 10.1002/bkcs.11334
  • Photophysical Study of 2-Fluorenyl-1,2,3-Triazole-labeled
           2′-Deoxyuridine and Its Oligonucleotide
    • Authors: Seung Woo Hong; Gil Tae Hwang
      Abstract: In this study, we prepared 2-fluorenyl-1,2,3-triazol-4-yl-2′-deoxyuridine (UFT) and inserted it at the central position of an oligodeoxynucleotide (ODN) to investigate whether the triazole group is an efficient linker between fluorene and uracil. UFT displays different fluorescence intensities and emission maxima in different solvents, indicating its potential for application as an environmentally sensitive probe. Moreover, excimer emission from UFT was observed in water. However, UFT containing ODN did not exhibit selective thermal stability and fluorescence changes upon duplex formation with matched and single-base mismatched targets. This highlighted the importance of selecting the appropriate linker to connect the fluorophore to the nucleobase when developing such DNA probes.
      PubDate: 2017-12-12T03:00:46.682347-05:
      DOI: 10.1002/bkcs.11349
  • Synthesis and Preliminary Evaluation of 68Ga-NOTA-Biphenyl-c(RGDyK) for
           the Quantification of Integrin αvβ3
    • Authors: Un Chul Shin; Ki-Hye Jung, Ji-Ae Park, Ji Woong Lee, Jung Young Kim, Jongbum Seo, Kyo Chul Lee, Jae Yong Choi
      Abstract: Arginine-glycine-aspartate (RGD) peptide binds to the integrin αvβ3, which plays a crucial role in tumor angiogenesis and metastasis. Previously developed 68Ga-labeled cyclic RGD peptides are rapidly excreted from the circulatory system. In the present study, we developed a 68Ga-labeled cyclic RGD peptide with a biphenyl group between the chelator and RGD peptide, i.e., 68Ga-NOTA-biphenyl-c(RGDyK). Then, we performed the comparison with the reference compound, i.e., 68Ga-NOTA-c(RGDyK). 68Ga-NOTA-biphenyl-c(RGDyK) was 37% less hydrophilic than 68Ga-NOTA-c(RGDyK). For positron emission tomography imaging, 68Ga-NOTA-biphenyl-c(RGDyK) had a longer retention time and showed a higher signal-to-noise ratio in tumors than 68Ga-NOTA-c(RGDyK). However, the biphenyl-radiopeptide displayed the relatively high non-specific binding. From these perspectives, incorporation of the biphenyl group to the RGD generates pros and cons.
      PubDate: 2017-12-01T06:40:36.245789-05:
      DOI: 10.1002/bkcs.11316
  • Viability Studies of Cells on Nanostructured Surfaces With Various Feature
    • Authors: Geun-Oh Kim; Hoyeon Lee, Eungyung Ma, Chulhun Kang, Young-Uk Kwon
      Abstract: We demonstrate that the pore size of a nanoporous anodic aluminum oxide (AAO) membrane is critical for cell viability and cell adhesion upon HeLa cell growth on it, while other properties of membranes such as surface wettability and pore fraction show no such effects. After a human cancer cell, HeLa cell line, was seeded on AAO membranes with various pore sizes ranging from 18 to 150 nm, the adhered cell population and 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were measured. The cell adhesion and viability on the membrane with small pores (18 nm) were similar to those on the nonporous reference; however, they gradually decreased as the pore size increased. The decreased viability involves cell death as well as poor cell adhesion. We found that cyclo(l-arginylglycyl-l-α-aspartyl-d-phenylalanyl-l-cysteinyl), a well-known integrin receptor antagonist, drastically decreased the cell adhesion to the membranes. The data indicate that the cell adhesion to the nanoporous membranes may be mediated by integrin on the cell surface, plausibly explaining the pore size dependence of the cell adhesion and viability. Implications of the present results to related fields such as implants are discussed.
      PubDate: 2017-12-01T01:33:23.647148-05:
      DOI: 10.1002/bkcs.11325
  • Allylic Azide Rearrangements Investigated by Density Functional Theory
    • Authors: Han-Young Kang; Young Kee Kang
      Abstract: The allylic azide rearrangement experimentally studied by Sharpless group were investigated using density functional theory (DFT) methods at the M06-2X/6-31+G(d) level of theory. This sigmatropic process is concerted and occurs synchronously. The equilibrium populations were estimated from free energies of regioisomers involved in the rearrangement process. The estimated ratios of the regioisomers from computations were well consistent with the observed values. In particular, the influence of the hydrogen bonding on the stability of the transition states and regioisomers, during the course of the allylic azide rearrangement, was described by DFT calculations in detail. Computational results also supported the feasibility of the selective interception of the equilibrating isomers in the rearrangement by the azide-alkyne cycloaddition.The allylic azide rearrangments were investigated using density functional theory methods.
      PubDate: 2017-12-01T01:32:39.368926-05:
      DOI: 10.1002/bkcs.11318
  • Efficient Synthesis and Characterization of Monoprotected Symmetrical
           Poly(Ethylene Glycol) Diamine
    • Authors: Hyeri Jeong; Dayoung Youn, Jihye Nam, Jaehi Kim, Yoon-Sik Lee, Dong-Sik Shin
      Abstract: Solid-phase synthesis of monoprotected poly(ethylene glycol) (PEG) diamine is demonstrated. 2-Chlorotrityl chloride (2-CTC) resin was used as a solid support for inducing monofunctionalization using excess PEG diamine. Fmoc-monoprotected PEG was prepared from 2-CTC resin and fully characterized by high-performance liquid chromatography and electrospray ionization mass spectrometry. We envision that this strategy will provide an efficient method of preparing various kinds of heterobifunctional PEG molecules without a need for further purification steps.Solid-phase synthesis of monoprotected poly(ethylene glycol) (PEG) diamine is demonstrated. 2-Chlorotrityl chloride (2-CTC) resin was used as a solid support for inducing monofunctionalization using excess PEG diamine. Fmoc-monoprotected PEG was prepared from 2-CTC resin and fully characterized by high-performance liquid chromatography and electrospray ionization mass spectrometry.
      PubDate: 2017-12-01T01:32:26.401792-05:
      DOI: 10.1002/bkcs.11335
  • Testing Method for On-Site Measurement of Explosive Materials Contaminated
           on Travel Luggage Bag and Backpack Using Ion Mobility Spectrometry
    • Authors: Sung-Seen Choi; Chae Eun Son
      Abstract: Testing method for the on-site detection of explosive materials contaminated on the travel luggage bag (TLB) and backpack (BP) surfaces was established using ion mobility spectrometry (IMS) and smear matrix. Trinitrotoluene and 1,3,5-trinitro-1,3,5-triazacyclohexane were used as model explosive materials. Two sampling methods of rolling (with a metal roller) and handrubbing were used, and stainless steel mesh was used as the smear matrix for collection of explosive material. Testing parts of the TLB and BP were selected in consideration of contaminant accumulation, physical contact, and sample collection. Explosive materials deposited on polytetrafluoroethylene (PTFE) sheet were transferred to the testing part, the explosive materials existing on the testing part were collected using the smear matrix, and then the collected explosive materials were analyzed using IMS. High signal-to-noise ratio over 10 was applied for the determination of the minimum initial explosive concentration (Cmin_PTFE) to detect in IMS. The hand-rubbing method was much more efficient than the rolling method. The Cmin_PTFE values were different according to the testing parts. The Cmin_PTFE values of the TLB were higher than those of the BP. The experimental results were explained by difference in surface morphology of the testing areas. The testing method can be helpful to select the sampling parts and to collect the explosive materials for on-site security checks.
      PubDate: 2017-12-01T01:32:18.639144-05:
      DOI: 10.1002/bkcs.11338
  • Synthesis of Spirocyclohexadieneyl-2-Oxindoles by 6π-Electrocyclization
           of Trienes Derived from Wittig Reaction of Morita-Baylis-Hillman
           Carbonates and α,β-Unsaturated Aldehydes
    • Authors: Beom Kyu Min; Da Young Seo, Ji Yeon Ryu, Junseong Lee, Jae Nyoung Kim
      PubDate: 2017-12-01T01:31:41.223111-05:
      DOI: 10.1002/bkcs.11333
  • In Situ Probing Citrullinated Sites in a Peptide by Reactive Desorption
           Electrospray Ionization Mass Spectrometry
    • Authors: Eunbi Shin; Sangwon Cha
      Abstract: Citrullination is a post-translational modification that converts arginine into citrulline through deimination. As citrullination is accompanied by only about 1 Da increase in mass, ion signals of a citrullinated peptide in a mass spectrum are always overlapped with the isotope peaks of its control (a noncitrullinated form). Therefore, off-line, covalent labeling techniques on citrulline residues were usually employed to investigate citrullinated sites by mass spectrometry (MS). Recently, reactive desorption electrospray ionization (reactive DESI) MS was introduced as a tool for selective, in situ modification of target analytes. In reactive DESI MS, a chemical reagent that can readily react with a target analyte is sprayed onto a sample spot and resulting products are analyzed by MS. Here, we developed a reactive DESI MS method for determining the citrullinated sites in peptides by employing phenylglyoxal as a derivatization agent, and succeeded in selectively modifying a citrulline residue in a peptide.
      PubDate: 2017-12-01T01:31:34.499161-05:
      DOI: 10.1002/bkcs.11337
  • Preparation of Surface Imprinted Polymer D301-g-IIPDMC and its Recognition
           Selectivity Performance towards AuCl4−
    • Authors: Min Li; Xiao-yan Xue, Yong Wang, Fu-qiang An, Tuo-ping Hu, Jian-feng Gao
      Abstract: In this article, a new surface imprinted polymer D301-g-IIPDMC is successfully prepared using AuCl4− as a template. The adsorption and recognition performances of D301-g-IIPDMC for AuCl4− are studied by using a static method and competitive adsorption experiment. The experimental results show that D301-g-IIPDMC possesses very strong adsorption affinity and excellent recognition for AuCl4−. The adsorption capacity of D301-g-IIPDMC for AuCl4− is 831.08 mg/g, and the selectivity coefficient relative to CuCl42− is 128. The adsorption behavior is an endothermic spontaneous process, and fit well with pseudo-second order kinetic model and Freundlich adsorption isotherm model. Besides, D301-g-IIPDMC is desorbed easily and exhibits excellent reusability.The influence of adsorbent dosage on the adsorption performance. The adsorption efficiency of D301-g-IIPDMC for AuCl4− increases along with increasing the adsorbent dosage, and the adsorption efficiency could reach 97.25% at the adsorbent dosage of 0.05 g. This indicates that D301-g-IIPDMC can be used as adsorbents to recover AuCl4− effectively.
      PubDate: 2017-12-01T01:31:10.844861-05:
      DOI: 10.1002/bkcs.11345
  • Density Functional Theory Studies on the Stability of Alkaline Metal
           Complexes of Pentazole and Oxopentazole Anions
    • Authors: Insook Kang; Soo Gyeong Cho, Hai Whang Lee, Kiyull Yang
      Abstract: We performed calculations on alkaline metal ion complexes of pentazole N5− and oxopentazole anions ON5− using density functional theory methods to examine the stability of the complexes in the gas phase and in solution. The complexation energies and Gibbs energies were estimated, and the structures corresponding to local and global minima were also identified. In addition, the transition states along the decomposition pathways of the metal-complexed pentazole and oxopentazole were characterized to evaluate the kinetic stability of the complexes in the gas phase and in solution. The Gibbs energies for metal cation complexation were fairly negative in tetrahydrofuran (THF) solution. This reflected the good thermodynamic stability of the metal-complexed pentazole and oxopentazole. The kinetic stability of pentazole and oxopentazole was increased by several kilocalories per mole in the THF solution. Upon metal complexation, in the gas phase, the decomposition barrier of the pentazole was significantly reduced, while that of the oxopentazole was little changed. This showed that the metal cation preferentially bound to the oxygen atom rather than to one of the nitrogen atoms in the ring. In the THF solution, the decomposition barriers were rarely altered, when compared to the bare anions.
      PubDate: 2017-12-01T01:26:35.75255-05:0
      DOI: 10.1002/bkcs.11329
  • Polymerization of rac-Lactide Using Zinc(II) and Copper(II) Complexes of
    • Authors: Min Kyung Chun; Juhyun Cho, Saira Nayab, Jong Hwa Jeong
      Abstract: Diisoproxide derivatives, generated in situ, of novel enantiopure dichloro Cu(II) and Zn(II) complexes supported by N1,N1-dimethyl-N2-[(1R)-myrtenylmethyl]ethane-1,2-diamine were assessed in ring opening polymerization of rac-LA, which displayed excellent activity and stereoselectivity. (L)Cu(OCHMe2)2 resulted in complete conversion of monomer in 80 s and yielded PLA that gave preference for heterotactic enchainment with Pr = 0.84 at 25 °C.
      PubDate: 2017-11-29T05:55:30.253885-05:
      DOI: 10.1002/bkcs.11323
  • Phase-separated Nanodomains Formed by Coadsorption of Alicyclic and
           Aromatic Thiols on Au(111)
    • Authors: Taehyun Sung; Chang Hyun Lee, Jin Wook Han, Jaegeun Noh
      PubDate: 2017-11-29T05:51:13.878467-05:
      DOI: 10.1002/bkcs.11301
  • Improvement of Water-Adsorption Capacity of Silico-Aluminophosphates by
           Changing Si/Al Ratio and Impregnation of Hygroscopic Salt for Application
           of Adsorption Chiller
    • Authors: Sang Kyum Kim; Kanghee Cho, Young Woo Rhee, Jong-Nam Kim
      Abstract: We synthesized a series of silico-aluminophosphates with a CHA-type microporous structure (SAPO-34) under hydrothermal conditions with different silicon to aluminum (Si/Al) ratios and systematically studied the effect of the Si/Al ratio on the structural properties and the water-adsorption capacity of the SAPO-34 adsorbents. The crystallinity, pore volume and surface area of the SAPO-34 increased with an increasing the SiO2/Al2O3 up to 1.0, and the amount of water adsorption also increased with the same trend. However, as increasing the ratio more, these properties became worse. SAPO-34 with SiO2/Al2O3 = 1 exhibited the highest water adsorption amount (0.359 gwater/gsorbent) at 308 K and 30% relative humidity. In order to enhance the water-adsorption capacity further, we impregnated the SAPO-34 with hygroscopic salts, LiCl and CaCl2. The amount of water adsorption at 308 K and 30% relative humidity was increased up to 0.584 and 0.664 gwater/gsorbent for the LiCl@SAPO-34 and CaCl2@SAPO-34 respectively. However, after several cycles of adsorption (308 K, 12 Torr)—desorption (353 K, 42 Torr) conditions of typical adsorption chiller, the CaCl2@SAPO-34 lost more than 81% of its working capacity. On the other hand, LiCl@SAPO-34 maintained well the working capacity during five cycles. SAPO-34 impregnated with LiCl is a highly promising water adsorbent for the application of adsorption chiller.
      PubDate: 2017-11-29T05:51:03.113511-05:
      DOI: 10.1002/bkcs.11319
  • Novel Direct Synthesis of Asymmetrical Urea Compounds from Trichloroethyl
           Carbamates Using Catalytic DBU
    • Authors: Ho Seong Jang; Hee-Kwon Kim
      PubDate: 2017-11-27T07:15:27.493412-05:
      DOI: 10.1002/bkcs.11314
  • Synthesis and Characterization of an Open and a Cyclic Polyaza Complexes
           of Copper(II) Having Caged Moiety; Cyclization Through Copper(II) Enhanced
           Hydrolysis from Nitrile to Amide
    • Authors: Min Jeong Park; Min Ji Seo, Minchul Chung, Chee-Hun Kwak
      Abstract: The preparation, X-ray structure and properties of noncyclic (1) and cyclic (2) polyaza copper(II) complexes with caged moiety, and copper(II) enhanced hydrolysis of acetonitrile participated in the cyclization of 1 to 2 are reported. The average Cu-N distances of complex 1 and 2 are somewhat shorter than those of square-planar or square-pyramidal complexes of analogue [14]-membered ring copper(II) complexes. These results derived from the squeeze effect of caged moiety of bicyclononan. Reaction of formaldehyde and complex 1 in the presence of base in acetonitrile solution produced complex 2. In this catalytic route, coordination of acetonitrile onto Cu(II) ion, a Lewis acid, of complex 1 makes the electrophilicity of the carbon of nitrile increased. Absorption maximum of the complex 2 is shifted to somewhat shorter wavelength than that of the complex 1. It is supposed to the higher ligand field stabilization energy of complex 2, which has cyclized ligand, comparing that of the complex 1, which has open ligand. These complexes are stable against disproportionation in copper(I) state.The preparation, X-ray structure and properties of noncyclic (1) and cyclic (2) polyaza copper(II) complexes with caged moiety are discussed. Copper(II) enhanced hydrolysis of acetonitrile to acetamide is participated in the cyclization of 1–2.
      PubDate: 2017-11-27T07:11:26.84522-05:0
      DOI: 10.1002/bkcs.11303
  • Ligand Recognition Mechanism of Thiamine Pyrophosphate Riboswitch Aptamer
    • Authors: Heesoo Uhm; Sungchul Hohng
      Abstract: Riboswitches regulate gene expression by coupling ligand binding to a structural transition of the riboswitch, but the coupling mechanism is still controversial. We addressed this issue by characterizing both the ligand-free state of the Escherichia coli thiamine pyrophosphate (TPP) riboswitch aptamer and its structural transition upon ligand binding using single-molecule fluorescence resonance energy transfer (FRET). Our results reveal that the apo-aptamer dynamically samples a partially closed form resembling the holo-aptamer, but TPP binding occurs in both the open and partially closed forms with the same efficiency. Mutation studies reveal that the preformation of the aptamer secondary structure is critical for TPP binding, and that tertiary interaction is established after TPP binding.
      PubDate: 2017-11-27T07:11:16.255864-05:
      DOI: 10.1002/bkcs.11328
  • Preparation and Electrochemical Characterization of Polyoxometal
           Molybdophosphoric Acid Included Polyether Ether Ketone Composite for Water
    • Authors: Minjin Kim; Dae-Young Park, Yu-Ri Song, Boyoung Kim, Sang-Bong Moon, Jang-Hoon Chung
      PubDate: 2017-11-23T05:26:53.08665-05:0
      DOI: 10.1002/bkcs.11322
  • Cirsimaritin Contributes to the Estrogenic Activity of Cirsium japonicum
           var. maackii through the Activation of Estrogen Receptor α
    • Authors: Dahae Lee; Yujung Jung, Ji Yun Baek, Myoung-Sook Shin, Sanghyun Lee, Dae-Hyun Hahm, Sang Cheon Lee, Jae Suk Shim, Su Nam Kim, Ki Sung Kang
      Abstract: Phytoestrogens are naturally occurring plant-derived chemicals that exert female hormone-like activities similar to those of endogenous estrogens. The purpose of this study was to quantitate the estrogenic activity of six chemical constituents (apigenin, hispidulin, cirsimaritin, cirsimarin, pectolinarin, and linarin) of Cirsium japonicum var. maackii using several in vitro assays. Reporter gene activation by each compound was examined using a human breast cancer (MCF-7) cell-based transactivation assay. Proliferative activity was also examined using MCF-7 cells. Reporter gene activation in MCF-7 cells by cirsimaritin was significantly suppressed by co-administration of the estrogen receptor (ER) antagonist ICI 182,780, indicating that cirsimaritin is an ER agonist. Under experimental conditions simulating postmenopausal syndrome (i.e., a low concentration of estrogen), cirsimaritin exerted beneficial effects on MCF-7 cells by increasing estrogenic activity. These results suggest that cirsimaritin is an effective estrogenic compound that can improve postmenopausal symptoms.
      PubDate: 2017-11-23T05:21:20.415987-05:
      DOI: 10.1002/bkcs.11342
  • Efficient Synthesis and In Vitro Biological Evaluation of
           2,5-Diaryloxazoles as Potential Nitric Oxide Production Inhibitors
    • Authors: Ha Young Jang; Kongara Damodar, Jin-Kyung Kim, Jong-Gab Jun
      Abstract: An efficient first synthesis of 2,5-diaryloxazoles 1–5 was accomplished from commercially inexpensive precursors and in overall yields of 38–48%. The synthesis proceeds via α-aminoketones and cyclodehydration (Robinson–Gabriel reaction) as key step. Next, these oxazoles were examined for their inhibitory effect against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells and were found to display concentration-dependent inhibition of NO production without cytotoxicity. Of note, compound 3 (70.7%; IC50 = 2.33 μM) was identified as a potent inhibitor in view of its comparable inhibitory effect with the positive control, NG-monomethyl-L-arginine acetate (L-NMMA) (79.3%; IC50 = 4.51 μM) followed by compounds 5 (68.3%; IC50 = 2.30 μM) and 2 (53.9%; IC50 = 6.31 μM). As a whole, compound 3 may hold great promise for further development of NO production targeted anti-inflammatory agent.
      PubDate: 2017-11-23T05:20:30.995-05:00
      DOI: 10.1002/bkcs.11331
  • A Ratiometric Fluorescent Probe for Selective Detection of Hypochlorite
    • Authors: Zhijian Ou; Lei Shi, Wenli Huang, Shengzhao Gong, Haomei Liang, Haojia Hong
      Abstract: A new fluorescent probe based on rhodamine and naphthalimide was synthesized for the discrimination of hypochlorite anion. Upon addition of NaClO, the emission intensities ratio (I576 nm/I528 nm) of the probe 1 increased quickly accompanied with the obvious change of color. The probe 1 also exhibited highly selectivity and fast response to hypochlorite anion. Furthermore, the newly proposed probe has been applied for natural water samples, and a satisfied result was obtained.A ratiometric probe was synthesized for the discrimination of hypochlorite anion based on ring-open mechanism, and this probe showed a ratiometric fluorescent response (I576 nm/I528 nm), highly selectivity, and fast response upon addition of hypochlorite anion, as well as a sharp demarcation of color changes. Moreover, this fluorometric method has been successfully applied in the detection of hypochlorite anion at natural water samples.
      PubDate: 2017-11-17T07:06:06.740091-05:
      DOI: 10.1002/bkcs.11321
  • Lipid Hydrolysis Catalyzed by Graphene Oxide
    • Authors: Hong-Nhung Trinh; Lan-Huong Tran, ChangWoo Lee, Sei-Heon Jang
      Abstract: Graphene oxide (GO) is a two-dimensional carbon nanomaterial. It has oxygen-containing functional groups, including alcohols, epoxides, and carboxylic acids. Herein, we show that GO catalyzes the hydrolysis of typical lipid molecules—phospholipids, triacylglycerols, sphingomyelins, and cholesterol esters—at temperatures above 50 °C. Ester bonds at both 1- and 2-positions of phosphatidylcholine were hydrolyzed by GO, indicating that the hydrolysis reaction is non-regiospecific in nature. GO-mediated lipid hydrolysis was facilitated by ethanol with maximal activity at 60% ethanol, whereas lipid hydrolysis by porcine pancreatic lipase showed maximal activity at 30% ethanol. The catalytic efficiency of recovered GO for phosphatidylcholine hydrolysis was approximately 80% up to four cycles.
      PubDate: 2017-11-17T07:05:34.537571-05:
      DOI: 10.1002/bkcs.11326
  • Control of the Charge Carrier Concentration and Hall Mobility in PEDOT:PSS
           Thermoelectric Films
    • Authors: Sung Hyun Kim
      Abstract: We investigated the effect of graphene quantum dots (GQDs) on the thermoelectric properties of free-standing poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films. The electrical conductivity and Seebeck coefficient of the film containing 0.50 vol% GQDs are 164.60 S/cm and 34.85 μV/K, compared with 22.50 S/cm and 27.72 μV/K, respectively, for the pristine PEDOT:PSS film without GQDs. The power factor (PF) increased up to 22.37 μW/mK2, which is ~13 times higher than that (1.73 μW/mK2) of the pristine film through the selective dedoping of PEDOT by the chemical treatment. Thus, the improved PF is due to the optimized charge carrier concentration and increased Hall mobility by the morphological and structural evolution.
      PubDate: 2017-11-17T07:01:13.926526-05:
      DOI: 10.1002/bkcs.11327
  • Anion Intercalation into Graphite Cathodes in K+-containing High-Voltage
           Electrolytes: Problems Associated with Counter Anodes
    • Authors: Chunguk Park; Su Cheol Han, Myoungho Pyo
      PubDate: 2017-11-17T07:00:43.145195-05:
      DOI: 10.1002/bkcs.11330
  • Daltonkins A and B, Two New Carboxyethylflavanones from the Heartwood of
           Dalbergia tonkinensis
    • Authors: Nguyen Manh Cuong; Ngu Truong Nhan, Ninh The Son, Do Huu Nghi, To Dao Cuong
      PubDate: 2017-11-10T05:35:55.829577-05:
      DOI: 10.1002/bkcs.11313
  • Facile Synthesis of Isoindigo Derivatives from 3-Indolyl-2-Oxindoles with
    • Authors: Da Young Seo; Hwa Jung Roh, Beom Kyu Min, Jae Nyoung Kim
      PubDate: 2017-11-06T21:45:56.517582-05:
      DOI: 10.1002/bkcs.11317
  • Anticancer Activity of 2-Amino-substituted-1,4-naphthoquinone Derivatives
           in Ovarian Cancer Cells
    • Authors: Sujeong Shin; Haneul Lee, Cheolmin Jeon, Umma Hafsa Preya, Jung-Hye Choi, Jeong Ho Park
      Abstract: 2-Amino-substituted-1,4-naphthoquinone derivatives (10–17) were synthesized from coupling reaction between 1,4-dihydroxynaphthalene and amines in the presence of catalyst CeCl3.7H2O. Their anticancer activity was evaluated by using three ovarian cancer cells (A2780, SKOV3, and OVCAR3). Among the eight compounds, compound 13 containing metal chelating moiety had a relatively potent cytotoxic activity (IC50 
      PubDate: 2017-11-06T21:45:47.68452-05:0
      DOI: 10.1002/bkcs.11315
  • 1D Nickel Coordination Polymers with an Unnatural Amino Acid Prepared by
           in situ Double Michael Addition of Ethylenediamine to (E,E)-Muconic Acid
    • Authors: Junghwan Do; Jaeun Kang, Yeonsun Jung, Yong Sun Park, Allan J. Jacobson
      PubDate: 2017-11-06T21:45:45.065411-05:
      DOI: 10.1002/bkcs.11311
  • A New Synthesis of β-Keto Sulfones from Olefins Utilizing Novel
           Xanthate Reagents
    • Authors: Kieseung Lee
      PubDate: 2017-11-06T21:40:33.677376-05:
      DOI: 10.1002/bkcs.11302
  • Effect of Electrical Ground Connection on Plant Growth
    • Authors: Min Ju Chang; Chang Joong Kim, Yong-Keun Choi, Hak Jin Song, Sok Young Shim, Sang Hyun Lee, Yung-Hun Yang, Kwang Jin Kim, Hyung Joo Kim
      PubDate: 2017-11-03T00:46:13.642986-05:
      DOI: 10.1002/bkcs.11304
  • A Novel Computational Method for Biomedical Binary Data Analysis:
           Development of a Thyroid Disease Index Using a Brute-Force Search with MLR
    • Authors: Jin Kak Lee; Won Seok Han, Jun-Seok Lee, Chang No Yoon
      Abstract: The thyroid disease index (TDI), which estimates thyroid disease progress based on hormone concentration measurements and hormone pattern changes, was developed. In this study, we measured concentrations of hormone profiles in the androgen and estrogen metabolic pathways from 23 patients with thyroid disease, as well as 20 unaffected people. We illustrated that the hormones 2-hydroxyestrone (2-OH-E1), 2-hydroxyestradiol (2-OH-E2), 2-methoxyestrone (2-MeO-E1), 2-methoxyestradiol (2-MeO-E2), and 2-methoxyestradiol-3-methylether (2-MeO-E2-3-methylether) are related to the development of thyroid disease through t-tests. Though the concentration levels of these hormones generally increase as the disease progresses, big fluctuations cause the determining of a disease's progress by measuring hormone levels to be difficult. The differing patterns between the correlation matrices of the disease and control groups possibly indicates changes in hormone releasing patterns during the thyroid disease's progress. Because of a lack of progressive experimental data on thyroid disease, binary data for the two categories (the thyroid disease patients and the control group) was utilized. Binary logistic regression was used to analyze five risk factors associated with thyroid disease, and the highest overall accuracy was 97.7% with three risk factors. Logistic regression models, however, are unable to describe disease progress. Hence, the TDI was developed to estimate thyroid disease progress. An arbitrary ranking of disease progress was generated for the TDI equation. The ranking contained a total number of 29 030 400 entries with six stages from the control group and eight stages from the disease group. Multiple linear regression (MLR) analysis was performed with a brute-force search. The best result among the MLR runs presented strong correlation (r2 values of 0.840 and q2 values of 0.663) between the selected hormones and the values of the disease progress in the training set. Overall accuracy of our novel method was 90.7%, which is worse than the 97.7% of logistic regression models. Brute-force search with MLR analysis might classify different types of thyroid disease progress such as thyroid mass (0.8055), goiter (0.8806), thyroid mass which was a thyroid cancer before operation (0.8951 and 0.9112), and cancer (1.001–2.144). The results show that the TDI is a good indicator of thyroid disease progress and that brute-force search with MLR analysis is useful for biomedical binary data analysis.
      PubDate: 2017-10-27T07:36:16.460602-05:
      DOI: 10.1002/bkcs.11308
  • Separation of Oil/Water Mixtures Using Water-Repellent Particles Coated by
           a Bioinspired Catechol-based Polymer
    • Authors: Woohee Lee; Yonghyun Ahn
      PubDate: 2017-10-27T07:36:03.124024-05:
      DOI: 10.1002/bkcs.11310
  • Diethyl Azodicarboxylate-promoted Oxidative Coupling Reaction of N-Phenyl
           Tetrahydroisoquinoline with β-Keto Acids
    • Authors: Yong Hwan Kim; Min Gyun Gil, Dae Young Kim
      PubDate: 2017-10-27T07:35:21.520762-05:
      DOI: 10.1002/bkcs.11307
  • A Solar-driven Microbial Electrolysis Cell for Hydrogen Production from
    • Authors: Jun Hyun Kim; Yongwon Jeon, Sunghyun Kim
      PubDate: 2017-10-27T07:31:10.335718-05:
      DOI: 10.1002/bkcs.11305
  • Electrochemical Deposition of Protein-conjugated Graphene by Pulse Reverse
    • Authors: Dinakaran Thirumalai; Seung-Cheol Chang
      Abstract: A simple electrochemical deposition method for the immobilization of protein-conjugated graphene onto an electrode has been developed. A unique one-step electrochemical deposition of cytochrome c (Cyt c) conjugated with electrochemically reduced graphene oxide (ErGO) onto the surface of glassy carbon electrode (GCE) without any cross-linkers and the direct electron transfer between Cyt c and the electrode was obtained by the Cyt c–ErGO-modified GCE. The characteristics of the ErGO–Cyt c-modified GCE were compared with those of an ErGO-modified GCE without Cyt c. The direct electron transfer rate constant (ket) was found to be 6.2/s. This approach provides an avenue for the immobilization of various proteins and enzymes with ErGO and could be expanded for diverse biosensor applications.
      PubDate: 2017-10-27T07:31:01.289175-05:
      DOI: 10.1002/bkcs.11309
  • Cover BKCS 12/2017
    • Pages: 1377 - 1377
      PubDate: 2017-12-14T08:46:07.263313-05:
      DOI: 10.1002/bkcs.10956
  • Masthead BKCS 12/2017
    • Pages: 1379 - 1380
      PubDate: 2017-12-14T08:46:10.113117-05:
      DOI: 10.1002/bkcs.10957
  • The Use of D2 Collision Gas in Isotope Dilution for the Analysis of Se
           with Octopole Reaction Cell Inductively Coupled Plasma-Mass Spectrometry
    • Authors: Lee-Won Kim; Yong-Nam Pak
      Pages: 1405 - 1410
      Abstract: D2 was used as a collision/reaction cell gas in Ar inductively coupled plasma-mass spectrometry for the analysis of selenium with an isotope dilution method. In conventional H2 collision gas, 80[BrH] was generated by the reaction of collision gas with Br in matrix. The use of D2 could generate 81[BrD] instead of 80[BrH], making it possible for the use of m/z 80, which has the highest abundance among Se isotopes. Two collision gases, H2 and D2, were compared with each other for the isotope spikes of 76Se, 77Se, and 78Se. For an inorganic selenium standard, both gases showed good results of 99% accuracy and below 1% Relative Standard Deviation (RSD). However, for complex-matrix samples, the results were different. For NIST SRM 1567b (wheat flour), which had a relatively simple matrix, accuracy and precision were similar for both gases. For KRISS CRM 108-04-001(oyster) and NIST SRM 2976 (mussel), which had a relatively high level of Br matrix, deuterium gas showed better accuracy and precision. For H2, 77Se showed the highest accuracy (98.4% recovery) but low precision (3.24% RSD). For deuterium, all three spikes showed good results, 98% average recovery and less than 1% RSD. The use of D2 collision gas demonstrates that it is effective for the accurate determination of Se, even for a complex matrix.
      PubDate: 2017-12-06T03:05:43.366881-05:
      DOI: 10.1002/bkcs.11312
  • A Hydrogen Pyrophosphate Selective Anion Receptor Based on
    • Authors: Thiravidamani Senthil Pandian; Venkatesan Srinivasadesikan, Ming-Chang Lin, Jong IL Park, Jongmin Kang
      Pages: 1435 - 1442
      Abstract: A novel rigid anion receptor 1 containing thiosemicarbazone groups were synthesized. Receptor 1 displayed competitive turn-off fluorescence and colorimetric response for hydrogen pyrophosphate. This recognition process was confirmed by UV–vis, fluorescence titrations. A detailed analysis of the TD-density functional theory calculations was consistent with the observed colorimetric experiments. These experiments revealed that the colorimetric and fluorescent response is triggered by thiourea/ HP2O73− hydrogen bonding.
      PubDate: 2017-12-05T21:16:27.233467-05:
      DOI: 10.1002/bkcs.11320
  • Fabrication of Colloidal Gold Nanoparticles via Galvanic Replacement in
           Disproportionation of H2O2 Solution and Their Inverse Photoresponse
    • Authors: Kang Yeol Lee; Hyunjin Park, Tae Ho Kim, Jineun Kim
      Pages: 1495 - 1498
      PubDate: 2017-12-06T03:07:45.678004-05:
      DOI: 10.1002/bkcs.11306
  • Water-assisted Dimerization of Hydrogen Cyanide: A Computational Study
    • Authors: Joong Chul Choe
      Pages: 1531 - 1533
      PubDate: 2017-12-05T21:11:30.30473-05:0
      DOI: 10.1002/bkcs.11324
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