bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfur and Its Role In Modern Materials Science
Authors: Boyd Darryl A. 
Published: November 2016

AbstractAlthough well‐known and studied for centuries, sulfur continues to be at the center of an extensive array of scientific research topics. As one of the most abundant elements in the Universe, a major by‐product of oil refinery processes, and as a common reaction site within biological systems, research involving sulfur is both broad in scope and incredibly important to our daily lives. Indeed, there has been renewed interest in sulfur‐based reactions in just the past ten years. Sulfur research spans the spectrum of topics within the physical sciences including research on improving energy efficiency, environmentally friendly uses for oil refinery waste products, development of polymers with unique optical and mechanical properties, and materials produced for biological applications. This Review focuses on some of the latest exciting ways in which sulfur and sulfur‐based reactions are being utilized to produce materials for application in energy, environmental, and other practical areas.
Metal Fluorides as Analogues for Studies on Phosphoryl Transfer Enzymes
Authors: Jin Yi , Richards Nigel G. , Waltho Jonathan P. , Blackburn G. Michael 
Published: November 2016

AbstractThe 1994 structure of a transition‐state analogue with AlF4− and GDP complexed to G1α, a small G protein, heralded a new field of research into the structure and mechanism of enzymes that manipulate the transfer of phosphoryl (PO3−) groups. The number of enzyme structures in the PDB containing metal fluorides (MFx) as ligands that imitate either a phosphoryl or a phosphate group was 357 at the end of 2016. They fall into three distinct geometrical classes: 1) Tetrahedral complexes based on BeF3− that mimic ground‐state phosphates; 2) octahedral complexes, primarily based on AlF4−, which mimic “in‐line” anionic transition states for phosphoryl transfer; and 3) trigonal bipyramidal complexes, represented by MgF3− and putative AlF30 moieties, which mimic the geometry of the transition state. The interpretation of these structures provides a deeper mechanistic understanding into the behavior and manipulation of phosphate monoesters in molecular biology. This Review provides a comprehensive overview of these structures, their uses, and their computational development.
Preparation and characterization of the ethylene‐vinyl acetate copolymer partially hydrolyzed assisted by microwave radiation
Authors: Paradinha Matheus Moresco , Gonzalez Dias Fernanda Trindade , Wanke Cesar Henrique , de Lima Novello Júnia Capua , Tondo Eduardo Cesar , De Nardi Martins Johnny , Bianchi Otávio 
Published: November 2016

ABSTRACTEthylene‐vinyl acetate copolymer (EVA) was modified by hydrolysis using dielectric heating. The modified EVA was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis (TG), 1H Nuclear magnetic resonance (NMR), gel permeation chromatography, and small‐angle X‐ray scattering. The results showed that the EVA was hydrolyzed with degree between 36.1 and 42.6% according to 1H NMR and TG results. The relative reaction rate for the sample prepared in the oil bath was ∼9%/h, while in the dielectric was ∼150%/h for 15 min. This significant improvement was due to the specific effect of microwave‐assisted reactions through dipole rotation and ionic polarization contributions. The hydrolysis reaction promoted a reduction of the pendent group size of EVA backbone. This change directly contributed to increasing melt temperature, crystallization temperature, melt and crystallization enthalpies. Also, decreased the long period, increased the volume crystallinity, and caused reductions amorphous/crystalline interface and two‐phase model deviations. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44558.
RA‐dimer B, a New Dimeric RA‐series Cyclopeptide Incorporating Two Different Types of Cycloisodityrosine Units, from Rubia cordifolia L.
Authors: Hitotsuyanagi Yukio , Tsuchiya Takayuki , Ohata Masako , Yoshida Ayaka , Fukaya Haruhiko , Park Hyun Sun , Takeya Koichi , Kawahara Nobuo 
Published: November 2016

AbstractRA‐dimer B, a new cytotoxic RA‐series peptide, was isolated from the roots of Rubia cordifolia L. Its structure was elucidated on the basis of spectroscopic analysis to be a dimeric cyclopeptide composed of deoxybouvardin and allo‐RA‐V. Those two cyclopeptide units are connected by an ether linkage between the phenolic oxygen atom of deoxybouvardin and the ϵa carbon atom of Tyr‐6 of allo‐RA‐V. RA‐dimer B was synthesized by the coupling reaction of deoxybouvardin with the boronic acid derivative of allo‐RA‐V, and subsequent deprotection, confirming the relative stereochemistry and establishing the absolute configuration of this peptide. RA‐dimer B showed cytotoxic activity against human promyelocytic leukaemia HL‐60, human colonic carcinoma HCT‐116, and human renal cell carcinoma ACHN cells with IC50 values of 0.59, 0.54, and 0.74 μm, respectively.
Molecular basis and potential activity of HIV‐1 reverse transcriptase toward trimethylamine‐based compounds
Authors: Padariya Monikaben , Kalathiya Umesh , Baginski Maciej 
Published: November 2016

AbstractReverse transcriptase (RT) inhibitors are currently used to treat human immunodeficiency virus (HIV)‐1 infections. In this work, novel triethylamine derivatives were designed and studied by rigid and flexible docking and molecular dynamics (MD) approaches. An apo form of HIV‐1 RT was also studied by MD simulation to analyze comparative response of protein in ligand‐bound and ligand‐unbound forms. Among newly designed HIV‐1 RT inhibitors, compound HIV104 was the most potent inhibitor considering different docking results. Molecular docking results were further validated by MD simulations of an HIV‐1 RT/HIV104 complex using two independent software (Discovery Studio Client 3.1 and GROMACS) to perform comparative analysis. Results suggest that hydroxyl and carboxyl groups present at –R1 position in compounds favored strong H‐bond contacts as well as good interaction energy profile. Our MD results are consistent with the observations that conformational dynamics between the thumb and finger subdomains of HIV‐1 RT controls its dynamics on substrate binding and subsequent activity. MD studies of HIV‐1 RT/HIV104 provide insight into interrelatedness of residue scale interactions and global conformational change and also hint at the complex nature of allosteric inhibition. Thus, the results obtained from this study facilitate the design of potent HIV‐1 RT inhibitors.
Hinweise für den Ansatz der Betonzugfestigkeit beim Nachweis der Mindestbewehrung für frühen Zwang gemäß Eurocode 2‐2 (DIN EN 1992‐2/NA)
Authors: Haveresch Karlheinz , Maurer Reinhard , Tauscher Franka 
Published: November 2016

AbstractIm Dezember 2015 wurde die A1‐Änderung [1] zum deutschen Nationalen Anhang [2] von DIN EN 1992‐1‐1 veröffentlicht. Die Änderungen betreffen u. a. den Ansatz der wirksamen Betonzugfestigkeit bei der Ermittlung der Mindestbewehrung zur Begrenzung der Rissbreiten bei frühem Zwang. Der nachfolgende Beitrag erläutert die Hintergründe, warum eine entsprechende A1‐Änderung zu DIN EN 1992‐2/NA nicht erfolgt. Als Begründung für diese unterschiedliche Vorgehensweise werden die wesentlichen Unterschiede zwischen dem Hochbau und dem Brückenbau dargestellt.
UPLC‐MS/MS method for the determination of tobacco‐specific biomarker NNAL, tamoxifen and its main metabolites in rat plasma
Authors: Xiong Wei , Zhao Jiajia , Wang Ling , Jiang Xuehua 
Published: November 2016

AbstractCigarette smoke is known to interact with tamoxifen‐metabolizing enzymes and transporters and potentially affect its treatment outcome. 4‐(N‐nitrosomethylamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL) is an important metabolite of 4‐(methylnitro‐samino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) because it is frequently used as a biomarker to assess human smoke exposure. In order to study the potential pharmacokinetic interaction between cigarette smoke and tamoxifen in rats a UPLC‐MS/MS method for the simultaneous determination of NNAL and tamoxifen along with its metabolites in rat plasma has been developed and validated. Analytes were extracted with methanol and separated on a HSS T3 column by a gradient elution with the mobile phase consisting of acetonitrile and water. The lower limits of quantitation ranged from 0.05 to 0.62 ng/mL. Precisions showed RSD <15.8% and accuracy in the range 80.6–116.0%. Mean analyte recoveries ranged from 76.9 to 108.4%. The method was successfully applied to study the effects of cigarette smoke condensate (CSC), NNK and benzo(a)pyrene pre‐treatment on the pharmacokinetics of tamoxifen and its metabolites in rats. Significant effects of CSC, NNK, benzo(a)pyrene were observed on pharmacokinetics of tamoxifen and its metabolites. We also found that plasma NNAL levels are statistically significant correlated with plasma 4‐hydroxy‐tamoxifen and endoxifen.
Promoting Effect of Bismuth Oxide on Palladium for Low‐Temperature Carbon Monoxide Oxidation
Authors: Ma Dong‐Dong , Ding Ding , Huang Jun‐Jie , Zhang Hong , Zheng Yan‐Ping , Chen Ming‐Shu , Wan Hui‐Lin 
Published: November 2016

AbstractBy using a modified coimpregnation method, a multicomponent Pd&Bi(1.4)/TiO2‐N catalyst with hierarchical metal–metal oxide interfaces was prepared that showed a better activity and stability for low‐temperature CO oxidation than Pd/TiO2‐N and Pd/P25. The structural characterization and catalytic activity results proved that an appropriate amount of Bi species has a clear promoting effect on the Pd‐based catalyst. Particularly, the catalyst can be mass‐produced conveniently, which may be beneficial for versatile reactions and practical applications.
Selective Hydrogenation of 2‐Methylfuran and 2,5‐Dimethylfuran over Atomic Layer Deposited Platinum Catalysts on Multiwalled Carbon Nanotube and Alumina Supports
Authors: Kang Jungshik , Liang Xinhua , Guliants Vadim V. 
Published: November 2016

Abstract2‐Methylfuran (2MF) and 2,5‐dimethylfuran (DMF) were hydrogenated in the vapor phase to the corresponding tetrahydrofurans, linear 2‐ketones, and alcohols over Pt nanoparticles supported on multiwalled carbon nanotubes (MWCNTs) and alumina by atomic layer deposition. The hydrogenation behavior of sub‐nanometer Pt deposited on alumina was influenced by the acidity of the support. Relative to a commercial Pt/C catalyst, the Pt/MWCNT catalyst was found to contain similarly sized Pt nanoparticles that display a broader size distribution and significantly more n‐alkanes than oxygenates during hydrogenation of these alkyl‐substituted furans.
Wilkinson‐Type Immobilized Catalyst on Diamond Nanoparticles for Alkene Reduction
Authors: Queffélec Clémence , Schlindwein Simon H. , Gudat Dietrich , Silvestre Virginie , Rodriguez‐Zubiri Mireia , Fayon Franck , Bujoli Bruno , Wang Qi , Boukherroub Rabah , Szunerits Sabine 
Published: November 2016

AbstractThe immobilization of heterogeneous catalysts on solid support materials is an important task of current catalytic and materials science research. We report here the development of a diamond nanoparticles‐based Wilkinson's type catalyst for the reduction of olefins to saturated hydrocarbons. The strategy is based on the formation of rhodium(I)‐modified nanodiamonds (NDs–Rh) using a surface‐immobilized catechol phosphane ligand, to which rhodium metal centers can be coordinated. The resulting material was characterized by solid‐state NMR spectroscopy, X‐ray photoelectron spectroscopy, thermogravimetry, and TEM before testing the catalytic efficiency of the catalyst. Excellent hydrogenation efficiency with yields in the range of 85–99 % could be obtained with these new NDs–Rh catalysts, which showed in addition good recyclability without loss of activity.
Furan‐ and Thiophene‐Based Auxochromes Red‐shift Chlorin Absorptions and Enable Oxidative Chlorin Polymerizations
Authors: Xiong Ruisheng , Bornhof Anna‐Bea , Arkhypchuk Anna I. , Orthaber Andreas , Borbas K. Eszter 
Published: November 2016

AbstractThe de novo syntheses of chemically stable chlorins with five‐membered heterocyclic (furane, thiophene, formylfurane and formylthiophene) substituents in selected meso‐ and β‐positions are reported. Heterocycle incorporation in the 3‐ and 13‐positions shifted the chlorin absorption and emission to the red (up to λem=680 nm), thus these readily incorporated substituents function analogously to auxochromes present in chlorophylls, for example, formyl and vinyl groups. Photophysical, theoretical and X‐ray crystallographic experiments revealed small but significant differences between the behavior of the furan‐ and the thiophene‐based auxochromes. Four regioisomeric bis‐thienylchlorins (3,10; 3,13, 3,15 and 10,15) were oxidatively electropolymerized; the chlorin monomer geometry had a profound impact on the polymerization efficiency and the electrochemical properties of the resulting material. Chemical co‐polymerization of 3,13‐bis‐thienylchlorin with 3‐hexylthiophene yielded an organic‐soluble red‐emitting polymer.
Fine‐Tuning the Fluorescence Gain of FRET‐Type (Bodipy)(Bodipy′)‐NHC‐Iridium Complexes for CO Detection with a Large Virtual Stokes Shift
Authors: Halter Oliver , Fernández Israel , Plenio Herbert 
Published: November 2016

AbstractComplexes of the general formula [IrCl(cod)(bdp‐NHC‐bdp′)] and [IrCl(cod)(bdp‐NHC)] (bdp=bodipy=4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene, cod=1,5‐cyclooctadiene) were synthesized. The substitution reaction of cod with two molecules of CO converts weakly fluorescent into strongly fluorescent complexes [IrCl(CO)2(bdp‐NHC‐bdp′)] and [IrCl(CO)2(bdp‐NHC)]. Bdp and bdp“ form a fluorescence resonance energy transfer (FRET) pair and the excitation of bdp leads to a strong emission from bdp” with a virtual Stokes shift of 98 nm. The fluorescence gain (IFl[Ir(CO)2]]/IFl[Ir(cod)]=1.7) upon reaction with CO in this complex is modest. To increase the fluorescence gain, the quenching capacity of the transition metal was improved by increasing the electron density at iridium. This was achieved by substituting the metal‐bound chloride with an electron‐rich thiolate RC6H4S. Depending on the nature of the R substituent in [Ir(SC6H4R)(cod)(bdp‐NHC‐bdp′)], an improved fluorescence gain in the cod/CO substitution reaction of up to 4.3 was observed and up to 26 (from gain=5) in [Ir(SC6H4R)(cod)(bdp‐NHC)]. DFT calculations on closely related [Ir(SC6H4R)(cod)(bdp‐NHC)] complexes indicate that a photoinduced electron transfer mechanism is the dominant quenching pathway for the iridium thiolates with R=COMe, CF3, Cl, H, Me, tBu, OMe, NEt2. The CO‐responsive FRET complex was immobilized on paper, displaying a red fluorescent color upon exposure to CO.
Water‐Resistant and Transparent Plastic Films from Functionalizable Organic Polymers: Coordination Polymers as Templates for Solid‐State [2+2]‐Photopolymerization
Authors: Garai Mousumi , Biradha Kumar 
Published: November 2016

AbstractAn organic polymer containing cyclobutanes and amides as backbones and pyridyl groups as sidearms was synthesized by single‐crystal‐to‐single‐crystal (SCSC) [2+2]‐photopolymerization in the coordination polymers (CPs) of diene. The diene molecule was photo‐inactive in its crystals and formed a triply intertwined 1D‐helical CP with Cd(NO3)2 and Cu(NO3)2 salts. The 1D‐CP was transformed into a coordination polymer of organic polymers containing threefold interpenetrated 3D‐networks of CdSO4 topology through a [2+2]‐reaction in SCSC manner upon irradiation. The organic polymer was separated from its CPs and found to have an unusually high degree of polymerization for this type of reaction. Furthermore, the organic polymer was amenable for N‐alkylation reactions such as methylation, propylation, and decylation. The formate salts of the organic polymer and the methylated polymer were shown to form plastic films with a combination of properties such as high transparency, tensile strengths, gas permeability, thermal stability, water‐resistance, and resistance to other organic solvents. The methylated polymer was also able to capture chromate ions and anionic dyes from aqueous solutions.
Preparation of Polyfunctional Organozinc Halides by an InX3‐ and LiCl‐Catalyzed Zinc Insertion to Aryl and Heteroaryl Iodides and Bromides
Authors: Benischke Andreas D. , Le Corre Grégoire , Knochel Paul 
Published: November 2016

AbstractA catalytic system consisting of InCl3 (3 mol %) and LiCl (30 mol %) allows a convenient preparation of polyfunctional arylzinc halides via the insertion of zinc powder to various aryl iodides in THF at 50 °C in up to 95 % yield. The use of a THF/DMPU (1:1) mixture shortens the reaction rates and allows the preparation of keto‐substituted arylzinc reagents. In the presence of In(acac)3 (3 mol %) and LiCl (150 mol %), the zinc insertion to various aryl and heteroaryl bromides proceeds smoothly (50 °C, 2–18 h). Alkyl bromides are also converted to the corresponding zinc reagents in the presence of In(acac)3 (10 mol %) and LiCl (150 mol %) in 70–80 % yield.
Chiral Self‐Recognition between Stereogenic Tetrapalladium Units Affording Pd8 Chains Supported by Homochiral Tetraphosphines
Authors: Tanase Tomoaki , Morita Konomi , Otaki Risa , Yamamoto Kana , Kaneko Yukino , Nakamae Kanako , Kure Bunsho , Nakajima Takayuki 
Published: November 2016

AbstractBy using a chiral tetraphosphine, rac‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (rac‐dpmppm), linear octapalladium chains were synthesized as discrete molecules of [Pd8(μ‐rac‐dpmppm)4L2](BF4)4 (L=CH3CN, dmf, XylNC), [Pd8(μ‐rac‐dpmppm)4](BF4)4, and [Pd8(μ‐rac‐dpmppm)4(Cl)2](BF4)2, which are stable in the solution states and characterized by spectroscopic and crystallographic methods to reveal the octapalladium chains supported by homochiral four tetraphosphines. Variable‐temperature NMR studies for a 1:1 mixture of [Pd8(μ‐rac‐dpmppm)4(dmf)2](BF4)4 and [Pd8(μ‐meso‐dpmppm)4(dmf)2]‐(BF4)4 in [D7]DMF revealed that the Pd8 chains were dissociated at higher temperature (T≈140 °C) into the Pd4 units of {Pd4(μ‐rac‐dpmppm)2}2+ and {Pd4(μ‐meso‐dpmppm)2}2+, and they were thermodynamically self‐aligned to restore the Pd8 chains at lower temperature (T<60 °C), through perfect chiral self‐recognition between the stereogenic tetrapalladium units.
Effect of hospital volume on processes of breast cancer care: A National Cancer Data Base study
Authors: Yen Tina W. F. , Pezzin Liliana E. , Li Jianing , Sparapani Rodney , Laud Purushuttom W. , Nattinger Ann B. 
Published: November 2016

BACKGROUNDThe purpose of this study was to examine variations in delivery of several breast cancer processes of care that are correlated with lower mortality and disease recurrence, and to determine the extent to which hospital volume explains this variation.METHODSWomen who were diagnosed with stage I‐III unilateral breast cancer between 2007 and 2011 were identified within the National Cancer Data Base. Multiple logistic regression models were developed to determine whether hospital volume was independently associated with each of 10 individual process of care measures addressing diagnosis and treatment, and 2 composite measures assessing appropriateness of systemic treatment (chemotherapy and hormonal therapy) and locoregional treatment (margin status and radiation therapy).RESULTSAmong 573,571 women treated at 1755 different hospitals, 38%, 51%, and 10% were treated at high‐, medium‐, and low‐volume hospitals, respectively. On multivariate analysis controlling for patient sociodemographic characteristics, treatment year and geographic location, hospital volume was a significant predictor for cancer diagnosis by initial biopsy (medium volume: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.05‐1.25; high volume: OR = 1.30, 95% CI = 1.14‐1.49), negative surgical margins (medium volume: OR = 1.15, 95% CI = 1.06‐1.24; high volume: OR = 1.28, 95% CI = 1.13‐1.44), and appropriate locoregional treatment (medium volume: OR = 1.12, 95% CI = 1.07‐1.17; high volume: OR = 1.16, 95% CI = 1.09‐1.24).CONCLUSIONSDiagnosis of breast cancer before initial surgery, negative surgical margins and appropriate use of radiation therapy may partially explain the volume–survival relationship. Dissemination of these processes of care to a broader group of hospitals could potentially improve the overall quality of care and outcomes of breast cancer survivors. Cancer 2017;123:957–66. © 2016 American Cancer Society.
Prediagnostic alcohol consumption and colorectal cancer survival: The Colon Cancer Family Registry
Authors: Phipps Amanda I. , Robinson Jamaica R. , Campbell Peter T. , Win Aung Ko , Figueiredo Jane C. , Lindor Noralane M. , Newcomb Polly A. 
Published: November 2016

BACKGROUNDAlthough previous studies have noted an increased risk of colorectal cancer (CRC) among moderate to heavy alcohol consumers in comparison with nondrinkers, the relation between alcohol consumption and CRC survival remains unclear.METHODSCases of incident invasive CRC diagnosed between 1997 and 2007 were identified via population‐based cancer registries at 4 study sites in the Colon Cancer Family Registry. Study participants completed a risk‐factor questionnaire on prediagnostic behaviors, including wine, beer, and liquor consumption, at the baseline. Prospective follow‐up for survival was conducted for 4966 CRC cases. Cox regression was used to compare nondrinkers with individuals who consumed, on average, 1 or more servings of alcohol per day in the years preceding their CRC diagnosis with respect to overall and disease‐specific survival. Separate analyses by beverage type, stratified by patient and tumor attributes, were also performed. All models were adjusted for the age at diagnosis, sex, study site, year of diagnosis, smoking history, body mass index, and education.RESULTSPrediagnostic beer and liquor consumption was not associated with CRC survival; however, higher levels of wine consumption were modestly associated with a better prognosis overall (CRC‐specific hazard ratio [HR], 0.70, 95% confidence interval [CI], 0.48‐1.03; overall HR, 0.70; 95% CI, 0.53‐0.94). Similar patterns were noted in stratified analyses.CONCLUSIONSThese findings suggest that prediagnostic wine consumption is modestly associated with more favorable survival after CRC. Cancer 2017;123:1035–43. © 2016 American Cancer Society.
Hybrids of Metal Nanoclusters and Graphene‐Based Materials: Preparation, Properties and Applications
Authors: Koklioti Malamatenia A. , Tagmatarchis Nikos 
Published: November 2016

AbstractThere is a significant drive within the scientific community to meet the demanding requirements of advanced energy‐conversion and detection schemes. The advantageous features of incorporating graphene with sub‐nanometer‐sized metal nanoclusters (MNCs) have already revealed encouraging results in key areas of selective sensing of hazardous molecules, detection of biologically related structures, bioimaging and hydrogen evolution. This timely Focus Review explores recent progress in the preparation and properties of MNCs/graphene hybrid materials, mainly focusing on the discussion of their applications. Moreover, a brief outlook on the future development of MNCs/graphene hybrid materials aiming to broaden their spectrum of applications is also provided.