bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a probe based on poly(glycidyl methacrylate‐co‐vinylferrocene)‐coated Pt electrode for electrochemical detection of PTEN gene in PCR amplified samples from prostate tissues
Authors: Bas Salih Zeki , Maltas Esra , Sennik Busra , Yilmaz Faruk , Vural Hasibe Cingilli 
Published: March 2014

ABSTRACTIn this study, a new probe based on immobilization of amino linked oligonucleotide (NH2‐linked DNA) on poly(glycidyl methacrylate‐co‐vinylferrocene)‐coated Pt electrode was fabricated for the electrochemical detection of PTEN gene from human prostate tissues. The experimental parameters such as DNA immobilization time, DNA concentration, and target concentration were optimized. The selectivity of the NH2‐linked DNA probe was assessed with mismatch (MM) and noncomplementary (NC) sequences. The applicability of the NH2‐linked DNA probe to the PCR amplified samples correspond to PTEN gene from prostate tissues was evaluated. The immobilization of DNA on the copolymer was confirmed by FTIR, AFM, CV and DPV analysis. The PCR products were also identified by using agarose gel electrophoresis. The prepared probe indicated a linear range (10–100 μg mL−1) with a detection limit (4.7 μg mL−1) and a good selectivity of the NH2‐linked DNA probe toward target DNA sequence. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40638.
Reconstruction of a high‐quality metabolic model enables the identification of gene overexpression targets for enhanced antibiotic production in Streptomyces coelicolor A3(2)
Authors: Kim Minsuk , Sang Yi Jeong , Kim Joonwon , Kim Ji‐Nu , Kim Min Woo , Kim Byung‐Gee 
Published: March 2014

AbstractStreptomycetes are industrially and pharmaceutically important bacteria that produce a variety of secondary metabolites including antibiotics. Streptomycetes have a complex metabolic network responsible for the production of secondary metabolites and the utilization of organic residues present in soil. In this study, we reconstructed a high‐quality metabolic model for Streptomyces coelicolor A3(2), designated iMK1208, in order to understand and engineer the metabolism of this model species. In comparison to iIB711, the previous metabolic model for S. coelicolor, the predictive power of iMK1208 was enhanced by the recent insights that enabled the incorporation of an updated biomass equation, stoichiometric matrix, and energetic parameters. iMK1208 was validated by comparing predictions with the experimental data for growth capability in various growth media. Furthermore, we applied a strain‐design algorithm, flux scanning based on enforced objective flux (FSEOF), to iMK1208 for actinorhodin overproduction. FSEOF results identified not only previously known gene overexpression targets such as actII‐ORF4 and acetyl‐CoA carboxylase, but also novel targets such as branched‐chain α‐keto acid dehydrogenase (BCDH). We constructed and evaluated the BCDH overexpression mutant, which showed a 52‐fold increase in actinorhodin production, validating the prediction power of iMK1208. Hence iMK1208 was shown to be a useful and valuable framework for studying the biotechnologically important Streptomyces species using the principles of systems biology and metabolic engineering.
Neural differences in processing of case particles in Japanese: an fMRI study
Authors: Hashimoto Yosuke , Yokoyama Satoru , Kawashima Ryuta 
Published: March 2014

AbstractIntroductionIn subject–object–verb (SOV) languages, such as Japanese, sentence processing proceeds incrementally to the late presentation of the head (verb). Japanese case particles play a crucial role in sentence processing; however, little is known about how these particles are processed. In particular, it is still unclear how the functional difference between case particles is represented in the human brain.MethodsIn this study, we conducted an fMRI experiment using an event‐related design to directly compare brain activity during Japanese case particle processing among the nominative case ga, accusative case o, and dative case ni. Twenty five native Japanese speakers were asked to judge whether the presented character was a particle in a particle judgment task and whether the character ended with a specific vowel in a phonological judgment task, which was used as a control condition.ResultsA particle comparison demonstrated that the processing of ni was associated with significantly weaker brain activity than that of ga and o in the left middle frontal gyrus (MFG) and the inferior frontal gyrus (IFG). Significantly greater brain activity associated with ni relative to ga in the right IFG was also observed.ConclusionThese results suggest that the Japanese case particles ga, ni, and o are represented differently in the brain.
Systematic Tuning and Switching of Neutral and Ionic Phases in a Donor–Acceptor Chain Compound by Doping with Less‐Active Donors and by Pressure Application
Authors: Nakabayashi Keita , Miyasaka Hitoshi 
Published: March 2014

AbstractThe temperature‐induced stepwise neutral–ionic (N–I) phase transition in the covalently bonded donor–acceptor chain compound [Ru2(2,3,5,6‐F4PhCO2)4DMDCNQI]⋅ 2(p‐xylene) (2,3,5,6‐F4PhCO2−=2,3,5,6‐tetrafluorobenzoate; DMDCNQI=2,5‐dimethyl‐N,N′‐dicyanoquinodiimine) was systematically tuned over a wide temperature range using two techniques: 1) A chemical technique based on doping with a less‐active donor unit [Ru2II,II(F5PhCO2)4] (F5PhCO2−=pentafluorobenzoate), thereby providing an isostructural doped series [{Ru2II,II(2,3,5,6‐F4PhCO2)4}1−x{Ru2II,II(F5PhCO2)4}xDMDCNQI]⋅2(p‐xylene), with x=0.06, 0.10, 0.21, and 0.24; and 2) a physical technique, which was the application of hydrostatic pressure to the doped compounds. The stepwise N–I transition observed in the original compound was systematically varied in terms of the viewpoints of both transition temperature and transition features (stepwise or monotonic) dependent on the amount of dopants x. Application of pressure efficiently tuned the N–I transitions, with the oxidation phases being dramatically modified by applying only weak pressure up to 4 kbar. Even in cases that led to N–I transitions in small domains of the chains at ambient pressure, the application of pressure caused an expansion of the domains that enabled N–I transitions, finally leading to a complete change in the oxidation state of the chains, from neutral to ionic, accompanied by a change from a paramagnetic state to a ferrimagnetically ordered state.
Mesostructure from Hydration Gradients in Demosponge Biosilica
Authors: Neilson James R. , George Nathan C. , Murr Meredith M. , Seshadri Ram , Morse Daniel E. 
Published: March 2014

AbstractOrganisms of the phylum Porifera, that is, sponges, utilize enzymatic hydrolysis to concatenate bioavailable inorganic silicon to produce lightweight, strong, and often flexible skeletal elements called spicules. In their optical transparency, these remarkable biomaterials resemble fused silica, despite having been formed under ambient marine biological conditions. Although previous studies have elucidated the chemical mechanisms of spicule formation and revealed the extensive hydration of these glasses, their precise composition and local and medium‐range structures had not been determined. We have employed a combination of compositional analysis, 1H and 29Si solid‐state nuclear magnetic resonance spectroscopy, and synchrotron X‐ray total scattering to characterize spicule‐derived silica produced by the demosponge Tethya aurantia. These studies indicate that the materials are highly hydrated, but in an inhomogeneous manner. The spicule‐derived silica is, on average, perfectly dense for the given extent of hydration and regions of fully condensed and unstrained SiO networks persist throughout each monolithic spicule. To accommodate chemical strain and defects, the extensive hydration is concentrated in distinct regions that give rise to mesostructural features. The chemistry responsible for producing spicule silica resembles hydrolytic sol‐gel processing, which offers exceptional control over the precise local atomic arrangement of materials. However, the specific processing involved in forming the sponge spicule silica further results in regions of fully condensed silica coexisting with regions of incomplete condensation. This mesostructure suggests a mechanism for atomistic defect tolerance and strain relief that may account for the unusual mechanical properties of the biogenic spicules.
Ag/Au Mixed Sites Promote Oxidative Coupling of Methanol on the Alloy Surface
Authors: Xu Bingjun , Siler Cassandra G. F. , Madix Robert J. , Friend Cynthia M. 
Published: March 2014

AbstractNanoporous gold, a dilute alloy of Ag in Au, activates molecular oxygen and promotes the oxygen‐assisted catalytic coupling of methanol. Because this trace amount of Ag inherent to nanoporous gold has been proposed as the source of oxygen activation, a thin film Ag/Au alloy surface was studied as a model system for probing the origin of this reactivity. Thin alloy layers of AgxAu1−x, with 0.15≤x≤0.40, were examined for dioxygen activation and methanol self‐coupling. These alloy surfaces recombine atomic oxygen at different temperatures depending on the alloy composition. Total conversion of methanol to selective oxidation products, that is, formaldehyde and methyl formate, was achieved at low initial oxygen coverage and at low temperature. Reaction channels for methyl formate formation occurred on both Au and Au/Ag mixed sites with a ratio, as was predicted from the local 2‐dimensional composition.
The G‐Protein‐Coupled Neuropeptide Y Receptor Type 2 is Highly Dynamic in Lipid Membranes as Revealed by Solid‐State NMR Spectroscopy
Authors: Schmidt Peter , Thomas Lars , Müller Paul , Scheidt Holger A. , Huster Daniel 
Published: March 2014

AbstractIn spite of the recent success in crystallizing several G‐protein‐coupled receptors (GPCRs), a comprehensive biophysical characterization of these molecules under physiological conditions also requires the study of the molecular dynamics of these proteins. The molecular mobility of the human neuropeptide Y receptor type 2 reconstituted into dimyristoylphosphatidylcholine (DMPC) membranes was investigated by means of solid‐state NMR spectroscopy. Static 15N NMR spectra show that the receptor performs axially symmetric motions in the membrane, and several residues undergo large amplitude fluctuations. This was confirmed by quantitative measurements of the motional 1H,13C order parameter of the CH, CH2, and CH3 groups. In directly polarized 13C NMR experiments, these order parameters showed astonishingly low values of SCH=0.55, S=0.33, and S=0.17, which corresponds to segmental amplitudes of approximately 50° in the backbone and approximately 50–60° in the side chain. At physiological temperature, 2H NMR spectra of the deuterated receptor showed a narrow component that is indicative of molecular order parameters of S≤0.3 superimposed with a very broad spectrum that could stem from the transmembrane α‐helices. These results suggest that the crystal structures of GPCRs only represent a static snapshot of these highly mobile molecules, which undergo significant structural fluctuations with relatively large amplitudes in a liquid‐crystalline membrane at physiological temperature.
Aryl–Phenyl Scrambling in Intermediate Organopalladium Complexes: A Gas‐Phase Study of the Mizoroki–Heck Reaction
Authors: Fiebig Lukas , Schlörer Nils , Schmalz Hans‐Günther , Schäfer Mathias 
Published: March 2014

AbstractThe intramolecular aryl–phenyl scrambling reaction within palladium–DPPP–aryl complex (DPPP=1,3‐bis(diphenylphosphino)propane) ions was analyzed by state‐of‐the‐art tandem MS, including gas‐phase ion/molecule reactions. The Mizoroki–Heck cross‐coupling reaction was performed in the gas phase, and the intrinsic reactivity of important intermediates could be examined. Moreover, linear free‐energy correlations were applied, and a mechanism for the scrambling reaction proceeding via phosphonium cations was assumed.
Rotaxanes Synthesized Through Sodium‐Ion‐Templated Clipping of Macrocycles Around Nonconjugated Amide and Urea Functionalities
Authors: Ho Tsung‐Hsien , Lai Chien‐Chen , Liu Yi‐Hung , Peng Shie‐Ming , Chiu Sheng‐Hsien 
Published: March 2014

AbstractA single urea or amide functionality in a dumbbell‐shaped guest can be “clipped” by a macrocycle generated from a diamine and a dialdehyde through the templating effect of a Na+ ion (see scheme). The resulting imine‐containing rotaxanes can then be reduced to allow isolation of stable amine‐based rotaxanes.
m‐Metallaphenol: Synthesis and Reactivity Studies
Authors: Han Feifei , Wang Tongdao , Li Jinhua , Zhang Hong , Xia Haiping 
Published: March 2014

AbstractInvited for the cover of this issue is the group of Haiping Xia at the University of Xiamen. The image depicts their recent work on the chemistry of transition‐metal‐containing metallaaromatics, organometallic compounds derived from formal replacement of a (hydro)carbon segment in an organic aromatic ring by an isolobal transition‐metal fragment. Read the full text of the article at 10.1002/chem.201304957.
Multicomponent Reactions for Diverse Synthesis of N‐Substituted and NH 1,4‐Dihydropyridines
Authors: Wan Jieping , Zhou Youyi , Liu Yunyun , Fang Zheng , Wen Chengping 
Published: March 2014

AbstractThe multicomponent reactions of aldehydes, electron deficient alkynes and amines have been successfully
performed to yield a number of symmetrical 2,6‐unsubstituted 1,4‐dihydropyridines (1,4‐DHPs). This method has been found
generally applicable for the synthesis of both N‐substituted and N‐unsubstituted 1,4‐DHPs by employing
secondary amine to activate the alkyne component via enaminoester intermediates. The present method runs through an enamine
type activation, which is different from the known approach employing AcOH as solvent.
Carbon‐Double‐Bond‐Free Printed Solar Cells from TiO2/CH3NH3PbI3/CuSCN/Au: Structural Control and Photoaging Effects
Authors: Ito Seigo , Tanaka Soichiro , Vahlman Henri , Nishino Hitoshi , Manabe Kyohei , Lund Peter 
Published: March 2014

AbstractCarbon double bond‐free printed solar cells have been fabricated with the structure <F‐doped SnO2 (FTO)/dense TiO2/nanocrystalline TiO2/CH3NH3PbI3/Au> and <FTO/dense TiO2/nanocrystalline TiO2/CH3NH3PbI3/CuSCN/Au>, in which CuSCN acts as a hole conductor. The thickness of the CH3NH3PbI3 layer is controlled by a hot air flow during spin coating. The best conversion efficiency (4.86 %) is obtained with <FTO/dense TiO2/nanocrystalline TiO2/thin CH3NH3PbI3 (hot‐air dried)/CuSCN/Au>. However, a thick CH3NH3PbI3 layer on CuSCN is better for light‐exposure stability (100 mW cm−2 AM 1.5) when not encapsulated. Without the CuSCN coverage, the black CH3NH3PbI3 crystal changes to yellow during the light‐exposure stability test, which is due to the transformation of the CH3NH3PbI3 perovskite crystal into hexagonal PbI2.
The links between morphological parameters and benthic invertebrate assemblages, and general implications for hydromorphological river management
Authors: Petkovska Vesna , Urbanič Gorazd 
Published: March 2014

AbstractIn the last decades, hydromorphological degradation of rivers has gained more attention in river management, stressing the importance of understanding the links between hydromorphology and aquatic assemblages. The present study investigated general patterns in the response of benthic invertebrate assemblages to single morphological features along naturally diversified Slovenian rivers. The whole gradient of local habitat quality (river habitat quality, RHQ) and habitat modification (river habitat modification, RHM) features, according to the Slovenian hydromorphological assessment method, was covered. Regional natural characteristics explained the low share of RHQ and RHM variability, indicating nonregional presence of morphological features. The analysis identified predominant flow and predominant channel substrate as the most important RHQ features. We found that in contrast to RHQ features, RHM features had low explanatory power. These results suggest a weaker response of benthic invertebrate assemblages to the physical alteration itself than to the effect that the alteration exerts on habitat quality features. Variance partitioning among three environmental variable groups revealed predominantly independent effects (69%) on benthic assemblages, mostly on account of regional natural characteristics (30%) and RHQ features (31%). As benthic invertebrate assemblages are adapted to the former natural conditions, a similar modification may result in different effects with regard to regional natural differences. Therefore, the low proportion of variability, explained by RHM features, might be the consequence of joint dataset from different regions. Our study gives general implications for river management, but in order to more clearly define the significance of particular modification features, we suggest further analysis within more homogeneously defined habitats that encompass regional natural characteristics. Copyright © 2014 John Wiley & Sons, Ltd.
Kinetic Evidence of Tautomerism of Thiourea Dioxide in Aqueous Acidic Solutions
Authors: Csekő György , Hu Ying , Song Yanan , Kégl Tímea R. , Gao Qingyu , Makarov Sergei V. , Horváth Attila K. 
Published: March 2014

AbstractIndirect experimental evidence of the existence of a sluggish tautomerism of thiourea dioxide in acidic aqueous solution was discovered while studying its oxidation by chlorine dioxide. Thiourea dioxide slowly rearranges into aminoiminomethanesulfinic acid, but the reactivity of these two species towards chlorine dioxide marginally differs. It was clearly demonstrated that thiourea dioxide reacts with chlorine dioxide in a relatively slow reaction in an autocatalytic fashion with respect to the carbon(IV) species. In contrast, reaction of aminoiminomethanesulfinic acid with chlorine dioxide is orders of magnitude faster but proceeds through a normal second‐order process.
Inclusion: Conceptualization and measurement
Authors: Jansen Wiebren S. , Otten Sabine , van der Zee Karen I. , Jans Lise 
Published: March 2014

AbstractIn the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal distinctiveness theory and self‐determination theory, we proposed that inclusion is a hierarchical two‐dimensional concept consisting of perceptions of belonging and authenticity. In addition, we posed that in the process of inclusion, it is the group rather than the individual that has primary agency. From this conceptualization, we developed and validated the 16‐item perceived group inclusion scale (PGIS). Data from two samples supported our proposed configuration of inclusion. In addition, the PGIS appeared to be a reliable measure of inclusion and was demonstrated to possess both nomological and predictive validity. Taken together, this research contributes to the conceptual refinement of the inclusion construct and offers researchers a reliable and valid tool to conduct future inclusion research. Copyright © 2014 John Wiley & Sons, Ltd.
Cysteic Acid‐Modified Glassy Carbon Electrode for Monitoring Oxalic Acid (OA) Concentration During Its Electrochemical Oxidation at Ti/Pt Anode
Authors: Araújo Eliane G. , Jhones dos Santos Alexsandro , da Silva Djalma R. , Salazar Ricardo , Martínez‐Huitle Carlos A. 
Published: March 2014

AbstractThe aim of this manuscript is to develop a combined method for the detection and elimination of oxalic acid (OA) in aqueous environment. For that, the surface of glassy carbon (GC) electrode has been modified by oxidation of L‐cysteine using cyclic voltammetric (CV) technique. After modification, the formation of a compact and uniform cysteic acid layer film was achieved and it was confirmed by surface analysis (scanning electron microscopy (SEM) and atomic force microscopy (AFM)). Estimation of the linear range, calibration function and limit of detection for OA were performed by differential pulse voltammetry using Cysteine‐modified electrode (Cysteine‐MGC). Due to its stability and sensitive response to OA, it was used for monitoring OA during its electrochemical oxidation at Ti/Pt anode. DPV analyses have been compared with classic titration method and HPLC achieving a good fit, confidence intervals and limits. The results are described and discussed in the light of the existing literature.
Correlating the Electrochemical Kinetics of Myoglobin‐Films to pH Dependent Meat Color
Authors: Nerimetla Rajasekhara , Walgama Charuksha , Ramanathan Ranjith , Krishnan Sadagopan 
Published: March 2014

AbstractWe report here for the first time application of electrochemical kinetics to understand the myoglobin redox‐properties at three relevant meat pH conditions. We investigated the kinetics of oxymyoglobin formation electrochemically using films of myoglobin coated on high‐purity graphite electrodes. Three pH conditions corresponding to the physiological state (pH 7.4), stressed animal muscle (pH 6.4), and post‐mortem meat (pH 5.6) were examined in this study. Our findings show that slower metmyoglobin reduction rate and diminished oxygen‐affinity cause the discoloration of red‐meat at low acidic pH‐conditions in comparison to the physiological pH 7.4.
Using in situ cosmogenic 10Be to identify the source of sediment leaving Greenland
Authors: Nelson Alice H. , Bierman Paul R. , Shakun Jeremy D. , Rood Dylan H. 
Published: March 2014

ABSTRACTWe use the concentration of in situ 10Be in quartz isolated from fluvial and morainal sand to trace sediment sources and to determine the relative contribution of glacerized and deglaciated terrain to Greenland's sediment budget. We sampled along the western, eastern, and southern margins of the Greenland Ice Sheet, and collected sediment sourced from glacerized (n = 19) and non‐glacerized terrain (n = 10), from channels where sediment from glacerized and non‐glacerized terrain is mixed (n = 28), from Holocene glacial‐fluvial terraces (n = 4), and from one sand dune. In situ 10Be concentrations in sediment range from 1600 to 34 000 atoms g‐1. The concentration of in situ 10Be in sediment sourced from non‐glacerized terrain is significantly higher than in sediment sourced from glacerized areas, in mixed channel sediment, and in terrace sediment that was deposited during the Holocene. To constrain the timing of landscape exposure for the deglaciated portion of the Narsarsuaq field area in southern Greenland, we measured in situ 10Be concentration in bedrock (n = 5) and boulder (n = 6) samples. Paired bedrock and boulder ages are indistinguishable at 1σ uncertainty and indicate rapid exposure of the upland slopes at ~10.5 ka.The isotope concentration in sediment sourced from non‐glacerized terrain is higher than in sediment sourced from glacerized terrain because the non‐glacerized landscape has been exposed to cosmic radiation since early Holocene deglaciation. Sediment from glacerized areas contains a low, but measurable concentration of 10Be that probably accumulated at depth during a prolonged period of exposure, probably before the establishment of the Greenland Ice Sheet. The concentration of 10Be in mixed fluvial sediment and in terrace sediment is low, and similar to the concentration in sediment from glacerized areas, which indicates that the Greenland Ice Sheet is the dominant source of sediment moving through the landscape outside the glacial margin in the areas we sampled. Copyright © 2014 John Wiley & Sons, Ltd.