bluuebunny/crossref_metadata_2025 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

In 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.
When complexity becomes interesting
Authors: van der Sluis Frans , van den Broek Egon L. , Glassey Richard J. , van Dijk Elisabeth M. A. G. , de Jong Franciska M. G.
Published: March 2014

How to provide users a positive experience during interaction with information (i.e., the “Information eXperience” (IX)) is still an open question. As a starting point, this work investigates how the emotion of interest can be influenced by modifying the complexity of the information presented to users. The appraisal theory of interest suggests a “sweet spot” where interest will be at its peak: information that is novel and complex yet still comprehensible. This “sweet spot” is approximated using two studies. Study One develops a computational model of textual complexity founded on psycholinguistic theory on processing difficulty. The model was trained and tested on 12,420 articles, achieving a classification performance of 90.87% on two classes of complexity. Study Two puts the model to its ultimate test: Its application to change the user's IX. Using 18 news articles the influence of complexity on interest and its appraisals is unveiled. A structural equation model shows a positive influence of complexity on interest, yet a negative influence of comprehensibility, confirming a seemingly paradoxical relationship between complexity and interest. By showing when complexity becomes interesting, this paper shows how information systems can use the model of textual complexity to construct an interesting IX.
A grounded theory of the practice of web information architecture in large organizations
Authors: Burford Sally
Published: March 2014

Organizing and structuring online information becomes a mainstream activity within large organizations as increasing volumes of information are made available via the web. General methodologies, best practice, and guidelines for web information architecture (IA) have been developed and refined. This research paper extends the knowledge base for web IA by examining situated practice within large organizations and building theory to provide a deeper understanding of how large organizations construct information‐rich websites. A grounded theory, The Situated Practice of Web IA in Large Organizations, is proposed as an integrated theoretical framework for practice in this context. The theoretical framework is composed of 4 foundational constructs titled: owning, negotiating, enacting, and knowing web IA. Building on these foundations, an integrating central construct of practicing web IA is proposed. This theoretical framework will inform large organizations and practitioners as they approach web IA.
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

Streptomycetes 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

Introduction

In 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.

Methods

In 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.

Results

A 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.

Conclusion

These 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

The 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

Organisms 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

Nanoporous 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

In 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

The 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

A 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

Invited 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

The 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

Carbon double bond‐free printed solar cells have been fabricated with the structure  and , 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 . 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.
Dynamic output feedback consensus of continuous‐time networked multiagent systems
Authors: Zhao Huanyu , Park Ju H.
Published: March 2014

This article addresses the dynamic output feedback consensus problem of continuous‐time networked multiagent systems. Both a fixed topology and Markovian switching topologies are considered. The consensus algorithms are on the base of the output information of each agent's itself and its neighbors. Some sufficient conditions for consensus of multiagent systems are obtained in forms of bilinear matrix inequalities. The algorithm based on the homotopy continuation method is given to compute the feasible controller gains. Numerical simulations are given to show the effectiveness of the proposed results. © 2014 Wiley Periodicals, Inc. Complexity 20: 35–42, 2015
Opinion dynamics with the contrarian deterministic effect and human mobility on lattice
Authors: Guo Long , Cheng Yongjin , Luo Zhongjie
Published: March 2014

Opinion dynamics under the influence of the contrarian deterministic effect and human mobility on the two‐dimensional lattice is studied. In the model, the opinion is a binary variable and some shortcuts are added with the adding probability Ps. At each time step, each agent with shortcuts is chosen as the mobile one with the mobility probability Pm and moves to one of his immobile neighbors along shortcuts randomly. Then, the immobile agents update their opinions based on the majority rule with pf, which is the Fermi function of the interaction noise T due to the contrarian deterministic effect. We find that some appropriate interaction noise T enhances the formation of community around Tc. And human mobility enhances the formation of community when
, where Tc is equal to the average degree
and independent of the network size N and the mobility probability Pm through the theoretical and numerical analysis. Furthermore, we also find that the system with larger degree
and the self‐feedback of agent have stronger robustness in the opinion formation with the contrarian deterministic effect. © 2014 Wiley Periodicals, Inc. Complexity 20: 43–49, 2015
The links between morphological parameters and benthic invertebrate assemblages, and general implications for hydromorphological river management
Authors: Petkovska Vesna , Urbanič Gorazd
Published: March 2014

In 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

Indirect 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

In 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

The 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

We 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.
Remote‐controlled robotic platform ORPHEUS as a new tool for detection of bacteria in the environment
Authors: Nejdl Lukas , Kudr Jiri , Cihalova Kristyna , Chudobova Dagmar , Zurek Michal , Zalud Ludek , Kopecny Lukas , Burian Frantisek , Ruttkay–Nedecky Branislav , Krizkova Sona , Konecna Marie , Hynek David , Kopel Pavel , Prasek Jan , Adam Vojtech , Kizek Rene
Published: March 2014

Remote‐controlled robotic systems are being used for analysis of various types of analytes in hostile environment including those called extraterrestrial. The aim of our study was to develop a remote‐controlled robotic platform (ORPHEUS‐HOPE) for bacterial detection. For the platform ORPHEUS‐HOPE a 3D printed flow chip was designed and created with a culture chamber with volume 600 μL. The flow rate was optimized to 500 μL/min. The chip was tested primarily for detection of 1‐naphthol by differential pulse voltammetry with detection limit (S/N = 3) as 20 nM. Further, the way how to capture bacteria was optimized. To capture bacterial cells (Staphylococcus aureus), maghemite nanoparticles (1 mg/mL) were prepared and modified with collagen, glucose, graphene, gold, hyaluronic acid, and graphene with gold or graphene with glucose (20 mg/mL). The most up to 50% of the bacteria were captured by graphene nanoparticles modified with glucose. The detection limit of the whole assay, which included capturing of bacteria and their detection under remote control operation, was estimated as 30 bacteria per μL.
Determination of 8‐hydroxy‐2′‐ deoxyguanosine derivatized with 4‐chloro‐7‐ nitrobenzofurazan in urine by CE‐LIF
Authors: Meng Xiangying , Suo Xingmei , Ding Wenjun , Li Xiangjun , Ding Yongsheng
Published: March 2014

Oxidative DNA damage is a common type of damage caused by reactive oxygen species (ROS) in the body, resulting in cell mutation and cell death. 8‐Hydroxy‐2′‐deoxyguanosine (8‐OHdG), one of the major products of oxidative DNA damage, is widely accepted as a biomarker for oxidative stress. However, it is challenging for the measurement of 8‐OHdG in biological samples because of the trace amount of 8‐OHdG and complex matrices. In this study, a simple and sensitive method was developed for the determination of 8‐OHdG in urine by using CE‐LIF and precapillary derivatization of 8‐OHdG with 4‐chloro‐7‐nitrobenzofurazan (NBD‐Cl). The conditions related to the derivatization were optimized step by step. Under the optimum conditions, the derivative showed the largest peak area and was successfully separated from the interfering substances in the urine samples. The method was validated according to a FDA guideline. The RSDs of the peak area and migration time of the analyte at three different levels were within 2.97–6.88% and 0.17–1.13%, respectively. Good linearity between the peak area and the concentration of the analyte added into the urine samples was obtained within a range of 5–150 nM (R2 > 0.99). The LOD of 3.0 nM was obtained based on a S/N of 3:1. The recoveries at three different levels were within 97.5–102.6%. The developed method was applied for the analysis of 8‐OHdG in seven urine samples in comparison to an ELISA method.
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

We 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.
Fire behavior of regular and latent heat storage gypsum boards
Authors: Kontogeorgos D. A. , Mandilaras I. D. , Founti M. A.
Published: March 2014

This paper investigates the fire behavior of a regular and an energy storage gypsum board with latent heat storage characteristics when exposed to fire temperatures. Gypsum board samples, with and without a microencapsulated paraffin mixture phase change material, are studied at material and board level. At the material level, measurements of the physical properties, that is, mass and effective thermal conductivity, as a function of temperature, as well as differential scanning calorimetry experiments, in inert and oxidized environments, are performed. At the board level, specimens are inserted into a preheated oven, and the temperature evolution at preselected board locations is recorded. Both experimental procedures reveal significant information concerning the evolution of the various thermochemical processes taking place inside the gypsum boards during their heating. Results indicated the different fire behavior of the samples at different temperature ranges. At temperatures up to 300°C, the materials act as a fire retardant because of the dehydration of the free and chemically bound water contained in the gypsum boards. On the other hand, at temperatures higher than 300°C, the temperature rise within the samples is enhanced and accelerated because of the oxidation of the phase change material and their external finishing. Copyright © 2014 John Wiley & Sons, Ltd.
Transoral laser microsurgery for T1a glottic cancer: Review of 404 cases
Authors: Canis Martin , Ihler Friedrich , Martin Alexios , Matthias Christoph , Steiner Wolfgang
Published: March 2014

Background

Various therapeutic options exist for treatment of T1a glottic squamous cell cancer (SCC). Radiotherapy (RT) has been favored over surgical excision. This has been challenged by transoral laser microsurgery (TLM) showing low morbidity and good functional results.

Methods

A retrospective chart review was carried out. Patients with untreated T1a glottic SCC were included in the study. Endpoints were locoregional control, overall survival, disease‐specific survival, and absolute rate of larynx preservation.

Results

Four hundred four patients were included in this study. Five‐year Kaplan–Meier estimates were: local control 86.8%, overall survival 87.8%, disease‐specific survival 98.0%, recurrence‐free survival 76.1%, and larynx preservation 97.3%. The complication rate was 1%; the majority of patients had either normal or mildly dysphonic voices.

Conclusion

Low complication rates, excellent functional outcome, and high rates of organ preservation favor TLM. In agreement with the literature, TLM should be the treatment of choice for patients presenting with T1a glottic SCC. © 2014 Wiley Periodicals, Inc. Head Neck 37: 889–895, 2015
Soluble CD163, a macrophage activation marker, is independently associated with fibrosis in patients with chronic viral hepatitis B and C
Authors: Kazankov Konstantin , Barrera Francisco , Mφller Holger Jon , Bibby Bo Martin , Vilstrup Hendrik , George Jacob , Grφnbæk Henning
Published: March 2014

Macrophages are involved in inflammation and liver fibrosis and soluble (s)CD163 is a specific marker of activated macrophages. We investigated associations between sCD163 and biochemical and histological parameters of inflammatory activity and fibrosis in 551 patients with chronic hepatitis C virus (HCV) and 203 patients with chronic hepatitis B virus (HBV) before antiviral treatment. Scheuer histological scores of activity and fibrosis were obtained. Clinical, biochemical, and metabolic parameters were recorded. We measured sCD163 by enzyme-linked immunosorbent assay (ELISA). Soluble CD163 was higher in patients with HCV compared to HBV (3.6 [interquartile range (IQR) 2.5-5.4] versus 2.4 [IQR 1.8-3.6] mg/L, P < 0.001). sCD163 was associated with fibrosis stages for both HCV (odds ratio [OR] 1.49, 95% confidence interval [CI]: 1.38-1.61) and HBV (OR 1.32, 95% CI: 1.17-1.49) patients, with highest levels in patients with advanced fibrosis and cirrhosis. sCD163 was a marker of fibrosis independent of other biochemical parameters and known risk factors. We created two novel sCD163-based fibrosis scores, CD163-HCV-FS and CD163-HBV-FS, which showed areas under the receiver operating characteristics curve (AUROC) of 0.79 (95% CI: 0.74-0.83) and 0.71 (95% CI: 0.62-0.79), respectively, for significant fibrosis. Compared to existing fibrosis scores, CD163-HCV-FS was significantly superior to the aspartate aminotransferase (AST) to platelet ratio index (APRI) for all fibrosis stages and to FIB-4 for significant fibrosis, but CD163-HBV-FS was not. Conclusion: sCD163 levels are increased in patients with chronic viral hepatitis, reflecting macrophage activation. Increased sCD163 is associated with the severity of disease and predicts fibrosis. A sCD163-based fibrosis score, CD163-HCV-FS, is superior to APRI and FIB-4 for the diagnosis of significant fibrosis in patients with HCV infection. (Hepatology 2014;60:521–530)
Estimated intake of vitamin D and its interaction with vitamin A on lung cancer risk among smokers
Authors: Cheng Ting‐Yuan David , Goodman Gary E. , Thornquist Mark D. , Barnett Matt J. , Beresford Shirley A.A. , LaCroix Andrea Z. , Zheng Yingye , Neuhouser Marian L.
Published: March 2014

Data are very limited on vitamin D and lung cancer prevention in high‐risk populations. The authors investigated whether estimated vitamin D intake was associated with lung cancer risk and whether effect modification by vitamin A existed among current/former heavy smokers and workers with occupational exposure to asbestos. A case–cohort study selected 749 incident lung cancers and 679 noncases from the Carotene and Retinol Efficacy Trial (CARET), 1988–2005. The active intervention was supplementation of 30 mg β‐carotene + 25,000 IU retinyl palmitate/day. Baseline total intake including both diet (from food frequency questionnaire) and personal supplements (from brand names linked to the labeled potencies) was assessed. Hazard ratios (HRs) were estimated by Cox proportional hazard models. No significant association of total vitamin D intake with lung cancer was observed overall. However, total vitamin D intake ≥600 versus <200 IU/day was associated with a lower risk of non‐small cell lung cancer among former smokers [HR = 0.36, 95% confidence interval (CI) = 0.13–0.96]. Total vitamin D intake ≥400 versus <400 IU/day was associated with a lower risk of total lung cancer among participants who received the CARET active intervention (HR = 0.56, 95% CI = 0.32–0.99) and among those who had total vitamin A intake ≥1,500 µg/day retinol activity equivalent (RAE; HR = 0.46, 95% CI = 0.23–0.91). The beneficial associations were attenuated among those who did not receive the CARET active intervention or who had total vitamin A intake <1,500 µg/day RAE (p‐interaction = 0.02 for current smokers). Our observation suggests that vitamin A may assist vitamin D in preventing lung cancer among smokers.
Repair of Protein Radicals by Antioxidants
Authors: Domazou Anastasia S. , Gebicki Janusz M. , Nauser Thomas , Koppenol Willem H.
Published: March 2014

In vivo, proteins are the main targets for radicals and other reactive species. Their reactions result in formation of amino acid radicals on the protein surface that often yield tryptophan and tyrosyl radicals or, in the presence of O2, protein peroxyl radicals and hydroperoxides. All these species may propagate damage to biomolecules. Low molecular weight antioxidants, such as ascorbate, urate, and glutathione, are part of the defense system and function by repairing damaged proteins. We briefly review the existing knowledge about protein and amino acid radicals and their repair by antioxidants, including results of our investigations. The main question addressed is whether the antioxidants ascorbate, urate, and glutathione are able to repair amino acid radicals in model compounds and in proteinsin vitroby pulse radiolysis. We show that ascorbate and urate repair tryptophan and tyrosyl radicals efficiently and inhibit proton‐coupled electron transfer from tyrosine residues to tryptophan radicals in a number of proteins. In contrast, repair by glutathione is much slower. Ascorbate also rapidly reduces the peroxyl radicals of theN‐acetylamide derivatives of glycine, alanine, and proline, whereas glutathione reduces peroxyl radicals in lysozyme.In vivourate, ascorbate, and glutathione may prevent biological damage or, at least, reduce its rate, because they: (a) repair tryptophan and tyrosyl radicals in proteins and (b) reduce protein peroxyl radicals to the corresponding protein hydroperoxides. Most likely,in vivo, ascorbate and glutathione do not inhibit the reaction of C‐centered amino acid radicals with O2. Glutathione is less efficient that urate and ascorbate in repairing protein radicals; furthermore, the resulting glutathiyl radical is harmful. Ascorbate may be the more important repair agent in cells and tissues characterized by high ascorbate concentrations, such as the lens and brain; urate may be mainly responsible for repair in tissue compartments with higher urate concentrations, such as in plasma and saliva.
The impact of dispositional cynicism on job‐specific affect and work intentions
Authors: Roberts Taylor Peyton , Zigarmi Drea
Published: March 2014

Working from the Employee Work Passion Appraisal (EWPA) model, this article examines the relationship between employee dispositional cynicism, job‐specific affect (i.e. positive and negative) and work intentions including intent to use discretionary effort, intent to perform, intent to endorse, intent to stay and intent to be an organisational citizen. An online survey generated participation from 747 current and potential clients of an international consulting company. To evaluate the fit of the data in accordance with the EWPA framework, structural equation modeling was conducted to test the overall fit of the proposed model and to examine the hypothesised relationships between constructs. Analyses confirmed correlations between dispositional cynicism and job‐specific affect, supported notable relationships between positive job‐specific affect and all work intentions, provided evidence for job‐specific affect's mediation of cynicism and work intentions and uncovered a direct negative relationship between cynicism and intent to use organisational citizenship behaviour. Results suggest that state‐specific workplace emotions are important for understanding the degree to which employee dispositional cynicism will ultimately influence most performance‐related work intentions. However, independent of affect, employee cynicism may directly result in somewhat lower intentions to help others at work. Study limitations and practical implications for employee selection and training are considered.
A Bayesian statistical approach of improving knowledge‐based scoring functions for protein–ligand interactions
Authors: Grinter Sam Z. , Zou Xiaoqin
Published: March 2014

Knowledge‐based scoring functions are widely used for assessing putative complexes in protein–ligand and protein–protein docking and for structure prediction. Even with large training sets, knowledge‐based scoring functions face the inevitable problem of sparse data. Here, we have developed a novel approach for handling the sparse data problem that is based on estimating the inaccuracies in knowledge‐based scoring functions. This inaccuracy estimation is used to automatically weight the knowledge‐based scoring function with an alternative, force‐field‐based potential (FFP) that does not rely on training data and can, therefore, provide an improved approximation of the interactions between rare chemical groups. The current version of STScore, a protein–ligand scoring function using our method, achieves a binding mode prediction success rate of 91% on the set of 100 complexes by Wang et al., and a binding affinity correlation of 0.514 with the experimentally determined affinities in PDBbind. The method presented here may be used with other FFPs and other knowledge‐based scoring functions and can also be applied to protein–protein docking and protein structure prediction. © 2014 Wiley Periodicals, Inc.
The reactions of Cr(CO)6, Fe(CO)5, and Ni(CO)4 with O2 yield viable oxo‐metal carbonyls
Authors: Sun Zhi , Schaefer Henry F. , Xie Yaoming , Liu Yongdong , Zhong Rugang
Published: March 2014

Transition metal complexes with terminal oxo and dioxygen ligands exist in metal oxidation reactions, and many are key intermediates in various catalytic and biological processes. The prototypical oxo‐metal [(OC)5CrO, (OC)4FeO, and (OC)3NiO] and dioxygen‐metal carbonyls [(OC)5CrOO, (OC)4FeOO, and (OC)3NiOO] are studied theoretically. All three oxo‐metal carbonyls were found to have triplet ground states, with metal‐oxo bond dissociation energies of 77 (CrO), 74 (FeO), and 51 (NiO) kcal/mol. Natural bond orbital and quantum theory of atoms in molecules analyses predict metal‐oxo bond orders around 1.3. Their featured ν(MO, M = metal) vibrational frequencies all reflect very low IR intensities, suggesting Raman spectroscopy for experimental identification. The metal interactions with O2 are much weaker [dissociation energies 13 (CrOO), 21 (FeOO), and 4 (NiOO) kcal/mol] for the dioxygen‐metal carbonyls. The classic parent compounds Cr(CO)6, Fe(CO)5, and Ni(CO)4 all exhibit thermodynamic instability in the presence of O2, driven to displacement of CO to form CO2. The latter reactions are exothermic by 47 [Cr(CO)6], 46 [Fe(CO)5], and 35 [Ni(CO)4] kcal/mol. However, the barrier heights for the three reactions are very large, 51 (Cr), 39 (Fe), and 40 (Ni) kcal/mol. Thus, the parent metal carbonyls should be kinetically stable in the presence of oxygen. © 2014 Wiley Periodicals, Inc.
Remediation of soil contaminated by NAPLs using modified Fenton reagent: application to gasoline type compounds
Authors: Pardo Fernando , Rosas Juana M , Santos Aurora , Romero Arturo
Published: March 2014

BACKGROUND

A modified Fenton reaction was used for the remediation of a soil polluted with ethylbenzene (EB), a toxic compound in gasoline. Fe(III) and trisodium citrate were used as catalyst and chelating agent, respectively. pH remained near‐neutral during the process. Contaminant, chelating agent, oxidant and iron in solution were monitored at all times. A comparison between slurry (aqueous‐organic and soil phases) and liquid systems (aqueous‐organic phases) was carried out.

RESULTS

EB conversion increased as H2O2/EB ratios rose, for a given EB concentration. Furthermore, the contaminant conversion was decreased as the EB concentration increased, at a fixed H2O2/EB ratio. This indicates that the reaction takes place in the aqueous phase, with the oxidation rate limited by the EB concentration in this phase. The presence of soil produces a better contact between phases, enhancing EB transport from the organic to the aqueous phase. As EB was oxidized in the aqueous phase, the toxicity of this phase decreased, because non‐toxic oxidation byproducts were obtained. The chelant was oxidized, but not totally mineralized. This chelant oxidation produces precipitation of the catalyst from the aqueous phase.

CONCLUSIONS

The results suggest the suitability of modified Fenton reaction to remediate contaminated soils with non‐aqueous phase liquids. © 2014 Society of Chemical Industry
Electro‐Fenton decolourization of dyes in batch mode by the use of catalytic activity of iron loaded hydrogels
Authors: Bocos Elvira , Pazos Marta , Sanromán Maria Angeles
Published: March 2014

BACKGROUND

Electro‐Fenton technology has demonstrated great potential for the degradation of recalcitrant organic contaminants in polluted wastewaters. In this technology, the decomposition of hydrogen peroxide is catalysed by the presence of iron, and powerful oxidants, hydroxyl radicals, are generated. However, there is concern over the reduction of iron released in the treated effluent. Therefore, retention of catalyst is required, and advances in electro‐Fenton heterogeneous catalysis are necessary. In this study, the use of polyacrylamide hydrogel was evaluated as a support for the iron, and the performance of the catalyst (Fe‐PH) developed was assayed in the electro‐Fenton degradation of two dyes, Reactive Black 5 and Blue Sella Solid.

RESULTS

First, the synthesis of Fe‐PH catalyst was studied. The results showed that the loaded hydrogel with a mixture of Fe(II) and Fe(III) in 1:2 molar ratio reached the highest decolourization efficiency. The performance of the optimized Fe‐PH catalyst was evaluated in the decolourization of the selected dyes. These studies demonstrated the satisfactory performance of electro‐Fenton using Fe‐PH catalyst as well as its reusability.

CONCLUSION

In summary, the Fe‐PH catalyst developed gives the promise of wastewater treatment by means of an electro‐Fenton process. © 2014 Society of Chemical Industry