bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anodic‐Stripping Voltammetric Immunoassay for Ultrasensitive Detection of Low‐Abundance Proteins Using Quantum Dot Aggregated Hollow Microspheres
Authors: Zhang Bing , Tang Dianping , Goryacheva Irina Yu. , Niessner Reinhard , Knopp Dietmar 
Published: January 2013

AbstractA new anodic‐stripping voltammetric immunoassay protocol for detection of IgG1, as a model protein, was designed by using CdS quantum dot (QD) layer‐by‐layer assembled hollow microspheres (QDHMS) as molecular tags. Initially, monoclonal anti‐human IgG1 specific antibodies were anchored on amorphous magnetic beads preferably selective to capture Fab of IgG1 analyte from the sample. For detection, monoclonal anti‐human IgG1 (Fc‐specific) antibodies were covalently coupled to the synthesized QDHMS. In a sandwich‐type immunoassay format, subsequent anodic‐stripping voltammetric detection of cadmium released under acidic conditions from the coupled QDs was conducted at an in situ prepared mercury film electrode. The immunoassay combines highly efficient magnetic separation with signal amplification by the multilayered QD labels. The dynamic concentration range spanned from 1.0 fg mL−1 to 1.0 μg mL−1 of IgG1 with a detection limit of 0.1 fg mL−1. The electrochemical immunoassay showed good reproducibility, selectivity, and stability. The analysis of clinical serum specimens revealed good accordance with the results obtained by an enzyme‐linked immunosorbent assay method. The new immunoassay is promising for enzyme‐free, and cost‐effective analysis of low‐abundance biomarkers.
Asymmetric Distyrylpyridinium Dyes as Red‐Emitting Fluorescent Probes for Quadruplex DNA
Authors: Xie Xiao , Choi Bina , Largy Eric , Guillot Régis , Granzhan Anton , Teulade‐Fichou Marie‐Paule 
Published: January 2013

AbstractThe interactions of three cationic distyryl dyes, namely 2,4‐bis(4‐dimethylaminostyryl)‐1‐methylpyridinium (1 a), its derivative with a quaternary aminoalkyl chain (1 b), and the symmetric 2,6‐bis(4‐dimethylaminostyryl)‐1‐methylpyridinium (2 a), with several quadruplex and duplex nucleic acids were studied with the aim to establish the influence of the geometry of the dyes on their DNA‐binding and DNA‐probing properties. The results from spectrofluorimetric titrations and thermal denaturation experiments provide evidence that asymmetric (2,4‐disubstituted) dyes 1 a and 1 b bind to quadruplex DNA structures with a near‐micromolar affinity and a fair selectivity with respect to double‐stranded (ds) DNA [Ka(G4)/Ka(ds)=2.5–8.4]. At the same time, the fluorescence of both dyes is selectively increased in the presence of quadruplex DNAs (more than 80–100‐fold in the case of human telomeric quadruplex), even in the presence of an excess of competing double‐stranded DNA. This optical selectivity allows these dyes to be used as quadruplex‐DNA‐selective probes in solution and stains in polyacrylamide gels. In contrast, the symmetric analogue 2 a displays a strong binding preference for double‐stranded DNA [Ka(ds)/Ka(G4)=40–100), presumably due to binding in the minor groove. In addition, 2 a is not able to discriminate between quadruplex and duplex DNA, as its fluorescence is increased equally well (20–50‐fold) in the presence of both structures. This study emphasizes and rationalizes the strong impact of subtle structural variations on both DNA‐recognition properties and fluorimetric response of organic dyes.
Substituent Effects on the Structural Features and Nonlinear Optical Properties of the Organic Alkalide Li+(calix[4]pyrrole)Li−
Authors: Sun Wei‐Ming , Wu Di , Li Ying , Li Zhi‐Ru 
Published: January 2013

AbstractThe effects of substituents on the structure, character, and nonlinear optical (NLO) properties of the organic alkalide Li+(calix[4]pyrrole)Li− were studied by density functional theory. Natural bond orbital analysis and vertical ionization energies reveal that electron‐donating substituents strengthen the alkalide character of Li+(calix[4]pyrrole)Li− and that they are beneficial for a larger first hyperpolarizability (β0) value. However, electron‐withdrawing substituents have the opposite effect. The dependence of the NLO properties on the number of substituents and their relative position was detected in multisubstituted Li+(calix[4]pyrrole)Li− compounds. For both the amino‐ and methyl‐substituted derivatives, the polarizabilities and the first hyperpolarizabilities increase as more pyrrole β‐H atoms are substituted. Moreover, distribution of the substituents so that they are as far away from each other as possible resulted in an increase in the β0 value. The new knowledge obtained in this study may provide an effective approach to enhance the NLO responses of alkalides by employing pyrrole derivatives as complexants.
Hydrogen Dissociation Catalyzed by Carbon‐Coated Nickel Nanoparticles: Experiment and Theory
Authors: Yermakov Anatoliy Ye. , Boukhvalov Danil W. , Uimin Michael A. , Lokteva Ekaterina S. , Erokhin Alexey V. , Schegoleva Nina N. 
Published: January 2013

AbstractBased on the combination of experimental measurements and first‐principles calculations we report a novel carbon‐based catalytic material and describe significant acceleration of the hydrogenation of magnesium at room temperature in the presence of nickel nanoparticles wrapped in multilayer graphene. The increase in rate of magnesium hydrogenation in contrast to a mix of graphite and nickel nanoparticles evidences intrinsic catalytic properties of the nanocomposites explored. The results from simulation demonstrate that doping of the metal substrate and the presence of Stone–Wales defects turn multilayer graphene from being chemically inert to chemically active. The role of the size of the nanoparticles and temperature are also discussed.
Raising river level to improve the condition of a semi‐arid floodplain forest
Authors: Souter Nicholas J. , Wallace Todd , Walter Mark , Watts Richard 
Published: January 2013

ABSTRACTRiver red gum (Eucalyptus camaldulensis Denhn.) trees along the lower River Murray, Australia, have suffered severe dieback as a result of river regulation and drought. As an environmental flow initiative, the height of the lower River Murray in South Australia was raised during a period of increased flow in the spring and summer of 2005–2006. This was performed by increasing the level of the rivers in channel weirs. This increased the level of anabranch creeks on the Chowilla floodplain and through horizontal recharge freshened the adjacent groundwater, providing water to riparian river red gums. Groundwater depth rose concurrently with the rise in creek level, likely recharging the saline floodplain water table with fresh creek water. Multistate Markov modelling showed that along four creeks, most healthy trees responded positively to the rise in water level and remained healthy 1 year after the surcharge. Healthy trees were three times more likely to respond than stressed trees and thirty times more likely to respond than defoliated trees. Stressed trees were ten times more likely to respond than defoliated trees. Forty eight percent of trees that had no leaves at the start of the study responded to the surcharge by producing new growth. This study demonstrates how existing regulatory infrastructure can be used to manipulate water levels and that the hydrological connection between surface water and groundwater can be used to provide water to riparian trees. Copyright © 2013 John Wiley & Sons, Ltd.
Bisorganophosphonyl and ‐Organoarsenyl Derivatives of Heteropolytungstates as Hard Ligands for Early‐Transition‐Metal and Lanthanide Cations
Authors: Villanneau Richard , Djamâa Aïcha Ben , Chamoreau Lise‐Marie , Gontard Geoffrey , Proust Anna 
Published: January 2013

AbstractThe coordination properties of bisorganophosphonyl and bisorganoarsenyl derivatives of heteropolytungstates towards lanthanides and early‐transition‐metal cations were studied in organic medium. This new class of vacant polyoxometalate (POM) hybrids proved to conserve coordination sites after the grafting of the {RP=O}2+ or {RAs=O}2+ groups onto the trivacant A,α‐[PW9O34]9– and B,α‐[AsW9O33]9– platforms. The consequence of the presence of free {P=O} or {As=O} groups is an increase of the hardness of the coordination sites in these anions (according to Pearson's HSAB theory). Although soft divalent transition metal cations were hardly coordinated with these hybrid monovacant POMs, complexes with hard s group (Ca2+), lanthanide (La3+, Ce3+) and d0 early‐transition‐metal cations were obtained and studied, in particular by single crystal X‐ray diffraction. Owing to the possibility of modification of the trivacant platform, the type of the grafted function (phosphonyl or arsenyl) or the organic function R, these systems offer a unique possibility to finely modulate the coordination sphere of the cation.
Substituted 3(2H)‐Furanones by a Tandem Michael Addition/Palladium‐Catalyzed Ring‐Closing Protocol
Authors: John Jubi , Hopf Henning 
Published: January 2013

AbstractA novel palladium‐catalyzed route for the synthesis of substituted 3(2H)‐furanones from activated alkenes and 4‐chloroacetoacetate was developed. The first step of the tandem reaction is the Michael addition of an acetoacetate to the alkene followed by palladium‐catalyzed ring closure of the adduct to form the furanone. The reaction was extended to a number of substituted alkenes, and the corresponding substituted 3(2H)‐furanones were obtained in good to excellent yields.
Iodide‐Ion‐Catalyzed Carbon–Carbon Bond‐Forming Cross‐Dehydrogenative Coupling for the Synthesis of Indole Derivatives
Authors: Jia Zhenhua , Nagano Takashi , Li Xingshu , Chan Albert S. C. 
Published: January 2013

AbstractThe nBu4NI‐catalyzed intramolecular cross‐dehydrogenative coupling (CDC) reaction has been applied to the synthesis of 1H‐indole derivatives. Intramolecular oxidative coupling of N‐arylenamines proceeded in the presence of a catalytic amount of nBu4NI and tert‐butyl hydroperoxide (TBHP) to afford the corresponding 1H‐indole derivatives in good‐to‐excellent yields. A preliminary study of the synthesis of 3H‐indole is also reported. This is a rare example of the nBu4NI‐catalyzed C–C bond‐forming CDC reaction.
Absorbing boundary conditions: a spectral collocation approach
Authors: Benacchio T. , Bonaventura L. 
Published: January 2013

SUMMARYWe introduce a spectral collocation method for the discretisation of the shallow water equations on a one‐dimensional semi‐infinite domain, employing scaled Laguerre basis functions to obtain an accurate description of the solutions on finite regions of arbitrary size. The time discretisation is based on a semi‐implicit, semi‐Lagrangian approach that handles the highly inhomogeneous node distribution without loss of efficiency. The method is first validated on standard test cases and then applied to the implementation of absorbing open boundary conditions by coupling the semi‐infinite domain to a finite size domain on which the same equations are discretised by standard finite volume methods. Numerical experiments show that the proposed approach does not produce significant spurious reflections at the interface between the finite and infinite domain, thus providing a reliable tool for absorbing boundary conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Reactivity of Human IgM Binding Murine Monoclonal 6B6C1 (IgG2a) with Other Murine Monoclonal IgG Antibodies
Authors: Prince Harry E. , Yeh Cindy 
Published: January 2013

BackgroundApproximately 6% of sera positive in a dengue virus IgM‐capture enzyme immunoassay (EIA) represent false‐positives due to interaction between IgM and horseradish peroxidase (HRP)‐labeled monoclonal antibody (MAb) 6B6C1 (IgG2a). To better understand this interaction, we assessed the reactivity of captured IgM from these sera with other HRP‐labeled MAbs. J. Clin. Lab. Anal. 27:27–30, 2013. © 2012 Wiley Periodicals, Inc.MethodsFifty dengue IgM false‐positive sera (recognizing 6B6C1) were evaluated for IgM reactivity with the HRP‐labeled MAbs H3A4 (IgG2a), 53.8 (IgG2b), and IL‐A2 (IgG1). The sera were also tested in an EIA for human anti‐mouse antibody (HAMA).ResultsForty‐three sera (86%) reacted with IgG2a MAb (H3A4). Most (31/43 = 72%) of these sera recognizing 6B6C1 and H3A4 also recognized the IgG2 MAb and/or the IgG1 MAb. In contrast, HAMA was increased in only 9 of 50 (18%) sera reacting with 6B6C1.ConclusionsIgM from most sera‐binding IgG2a MAb 6B6C1 also binds another IgG2a MAb, suggesting that IgM‐6B6C1 reactivity is not idiotype specific. In many cases, IgM recognizing 6B6C1 also binds MAbs of other IgG subclasses, but is negative in a HAMA assay. These findings indicate that samples positive in IgM‐capture EIAs utilizing conjugated MAbs should always be retested in the absence of antigen to identify false‐positive reactivity caused by direct IgM‐MAb interaction. J. Clin. Lab. Anal. 00:1‐4, 2012. © 2012 Wiley Periodicals, Inc.
Neutrophil–Lymphocyte Ratio as a Predictor of Disease Severity in Ulcerative Colitis
Authors: Celikbilek Mehmet , Dogan Serkan , Ozbakır Omer , Zararsız Gökmen , Kücük Hamit , Gürsoy Sebnem , Yurci Alper , Güven Kadri , Yücesoy Mehmet 
Published: January 2013

BackgroundBlood neutrophil‐to‐lymphocyte (N/L) ratio is an indicator of the overall inflammatory status of the body, and an alteration in N/L ratio may be found in ulcerative colitis (UC) patients. The aims of this study were to investigate the utility of N/L ratio as a simple and readily available predictor for clinical disease activity in UC. J. Clin. Lab. Anal. 27:72–76, 2013. © 2012 Wiley Periodicals, Inc.MethodsTwenty‐six patients and 28 healthy controls were enrolled in the study. The neutrophil and lymphocyte counts were recorded, and the N/L ratio was calculated from these parameters. The extent of disease classified according to the Montreal classification, clinical disease activity was evaluated using a modified Truelove–Witts severity index, and endoscopic disease activities were classified according to Schroder et al.ResultsThe serum N/L ratios of active patients were significantly higher than those of inactive UC and controls (P < 0.001). The optimum N/L ratio cut‐off point for active UC was 2.47. There was no significant difference between inflammation parameters, disease extension, and disease activity.ConclusionOur results demonstrate that N/L ratio is higher in patients with active UC compared with controls and UC patients in remission and a cut‐off value of 2.47 can be used to identify patients with active ulcerative colitis.
Enzymatic hydrolysis enhanced by pressure shockwaves opening new possibilities in Jatropha Curcas L. processing
Authors: Maroušek Josef , Itoh Shigeru , Higa Osamu , Kondo Yoshikazu , Ueno Masami , Suwa Ryuichi , Tominaga Jun , Kawamitsu Yoshinobu 
Published: January 2013

AbstractBACKGROUNDLow yields of oil, hazardous organic solvents or demanding supercritical conditions hinder energy utilization of Jatropha Curcas L.RESULTSA new complex procedure for processing the oilseeds is presented. The method consists of deshelling, grinding, shockwave pretreatment, enzymatic hydrolysis, oil expelling, anaerobic fermentation and charcoal production. No additional energy, hazardous solvents or expensive catalysts are needed.CONCLUSIONSThe biotechnological impact of the processes involved was screened at different levels. Mass balances with kinetic data are plotted in detail, allowing further process modeling and technology design as well as determining the optimal operation parameters for further financial judgments. © 2013 Society of Chemical Industry
Gadoxetic acid‐enhanced fat suppressed three‐dimensional T1‐weighted MRI using a multiecho dixon technique at 3 tesla: Emphasis on image quality and hepatocellular carcinoma detection
Authors: Lee Mi Hee , Kim Young Kon , Park Min Jung , Hwang Jiyoung , Kim Seong Hyun , Lee Won Jae , Choi Dongil 
Published: January 2013

PurposeTo compare the image quality between T1 high‐resolution isotropic volume examination using the multi‐echo Dixon technique (mDixon‐eTHRIVE) and that using spectrally adiabatic inversion recovery (SPAIR‐eTHRIVE) in gadoxetic acid‐enhanced liver MRI, and to evaluate the detectability of hepatocellular carcinoma (HCC) on mDixon‐eTHRIVE.Materials and MethodsSeventy patients with 117 HCCs underwent gadoxetic acid‐enhanced liver MRI using mDixon‐eTHRIVE. All patients also underwent gadoxetic acid‐enhanced MRI using SPAIR‐eTHRIVE (mean interval of 96 days). Two radiologists performed a consensus review of MRIs for image quality, homogeneity of fat suppression, artifact, and anatomic sharpness using a four‐point scale. The detectability for HCC with mDixon‐eTHRIVE was assessed using alternative‐free response receiver operating characteristic.ResultsAll mDixon‐eTHRIVE images received higher scores for homogeneity of fat suppression and image quality (P < 0.05) compared with those for SPAIR‐eTHRIVE. With respect to artifact and anatomic sharpness, there was no significant difference between two MRIs (P > 0.05). Diagnostic accuracy (Az) and sensitivity for detecting HCCs with mDixon‐eTHRIVE images were mean 0.954 and 93.2%, respectively.ConclusionFor gadoxetic acid‐enhanced liver MRI, mDixon‐eTHRIVE showed improved homogeneity of fat suppression and overall image quality compared with SPAIR‐eTHRIVE. J. Magn. Reson. Imaging 2013;38:401–410. © 2013 Wiley Periodicals, Inc.
Study of morphology, mechanical properties, and thermal degradation of polycarbonate‐titania nanocomposites as function of titania crystalline phase and content
Authors: Motaung T.E. , Luyt A.S. , Saladino M.L. , Caponetti E. 
Published: January 2013

AbstractTitania nanoparticles were prepared using a sol–gel method and calcination at 200°C and 600°C to obtain anatase and rutile phases, respectively. The obtained powders were used to prepare polycarbonate (PC)‐titania nanocomposites by melt compounding. The effect of different crystalline phases and amounts of titania, in the range 1–5 wt%, on the morphology, mechanical properties, and thermal degradation kinetics of PC was investigated. The results show that the filler modified the plasticity or rigidity of the polymer and influenced the degradation kinetics, in different ways depending on the type and amount of titania. POLYM. COMPOS., 2012. © 2013 Society of Plastics Engineers
An atomistic simulation study of the effect of dopants on the morphology of YLiF4
Authors: Littleford Thomas E. , Jackson Robert A. , Read Mark S. D. 
Published: January 2013

AbstractSolid‐state optical materials are a continuing field of study that has many important applications including lasers. YLiF4 is one material has been studied in detail however, no studies into the surface properties or crystal morphology have been carried out. This paper summaries the key findings of a bulk study into the material and extends it to consider the morphology of pure YLiF4 before looking at the segregation of rare earth dopants to the low index surfaces. The presence of these dopants at the surfaces is shown to have a stabilising effect on some of the indices resulting in a lowering of the surface energy. By considering the optimum dopant coverage at all surfaces, a prediction for the doped La:YLiF4 crystal is made. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Emotion and moral judgment
Authors: Avramova Yana R. , Inbar Yoel 
Published: January 2013

AbstractResearch in psychology and cognitive science has consistently demonstrated the importance of emotion in a wide range of everyday judgments, including moral judgment. Most current accounts of moral judgment hold that emotion plays an important role, but the nature and extent of this role are still debated. We outline three increasingly strong claims about the role of emotion in moral judgment and assess the evidence for each. According to the first and least controversial claim, emotions follow from moral judgments, such that witnessing immorality can lead to negative emotions and witnessing moral virtue can lead to positive ones. According to the second claim, emotions amplify moral judgments, for instance, by making immoral acts seem even more immoral. Finally, on the last claim, emotions can actually moralize nonmoral behaviors—that is, they give nonmoral acts a moral status. Although this claim seems to be the most intriguing one theoretically, empirical support for it is still very limited. In this review, we discuss research findings that are in line with each of these views, we highlight recurring themes across these three categories of evidence, and we identify some open questions and areas for future research.WIREs Cogn Sci2013, 4:169–178. doi: 10.1002/wcs.1216This article is categorized under:Psychology > Emotion and Motivation
Chromatin looping and organization at developmentally regulated gene loci
Authors: Noordermeer Daan , Duboule Denis 
Published: January 2013

AbstractDevelopmentally regulated genes are often controlled by distant enhancers, silencers and insulators, to implement their correct transcriptional programs. In recent years, the development of 3C and derived techniques (4C, 5C, HiC, ChIA‐PET, etc.) has confirmed that chromatin looping is an important mechanism for the transfer of regulatory information in mammalian cells. At many developmentally regulated gene loci, transcriptional activation is indeed accompanied by the formation of chromatin loops between genes and distant enhancers. Similarly, dynamic looping between insulator elements and changes in local 3D organization may be observed upon variation in transcriptional activity. Chromatin looping also occurs at silent gene loci, where its function remains less understood. In lineage‐committed cells, partial 3D configurations are detected at loci that are activated at later stages. However, these partial configurations usually lack promoter–enhancer loops that accompany transcriptional activation, suggesting they have structural functions. Definitive evidence for a repressive role of chromatin looping is still lacking. Chromatin loops have been reported at repressed loci but, alternatively, they may act as a distraction for active loops. Together, these mechanisms allow fine‐tuning of regulatory programs, thus providing further diversity in the transcriptional control of developmentally regulated gene loci. WIREs Dev Biol 2013, 2:615–630. doi: 10.1002/wdev.103This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms