bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic behavior of ruthenium in soybean oil hydrogenation
Authors: Cizmeci Melih , Musavi Anar , Tekin Aziz , Kayahan Muammer 
Published: May 2009

AbstractSoybean oil was hydrogenated with a carbon‐supported ruthenium catalyst (Ru/C) at 165 °C, 2 bar H2 and 500 rpm stirring speed. Reaction rates, trans isomer formation, selectivity ratios and melting behaviors of the samples were monitored. No catalytic activity was found for the application of 10 ppm of the catalyst, and significant catalytic activity appeared at >50 ppm of active catalyst. The catalyst concentration had an effect on the reaction rate of hydrogenation, but the weight‐normalized reaction rate constant (kc) was almost independent of the catalyst concentration at lower iodine values. Ru/C generated considerable amounts of trans fatty acids (TFA), including high amounts of trans 18:2, and also stearic acid, due to its very non‐selective nature. The selectivity ratios were found to be low and varied between 1.12 and 4.32 during the reactions. On the other hand, because of the low selectivity, higher slip melting points and solid fat contents at high temperatures were obtained than those for nickel and palladium catalysts. Another different characteristic of this catalyst was the formation (max 1.67%) of conjugated linoleic acid (CLA) during hydrogenation. Besides, CLA formation in the early stages of the reactions did not change very much with the lower iodine values.
On the Electrophilicity of Cyclic Acylphosphoramidates (CAPAs) Postulated as Intermediates
Authors: Ni Feng , Gao Xiang , Zhao Zeng‐Xiang , Huang Chao , Zhao Yu‐Fen 
Published: May 2009

AbstractCyclic acylphosphoramidates (2‐hydroxy‐2‐oxy‐1,3,2‐oxazaphospholidine‐5‐ones, CAPAs) are phosphate‐activated amino acids possessing both a carboxyl–phosphoryl anhydride and a phosphoramidate bond in a ring. They structurally resemble NCAs (amino acidN‐carboxyanhydrides,Leuchs' anhydrides), which have been extensively investigated. By contrast, the chemistry of CAPAs has remained almost unexplored since it was proposed in a prebiotic reaction of inorganic polyphosphates (PolyPs) with amino acids. In the present work, the bielectrophilicity of α‐CAPAs (Gly‐CAPA, Ala‐CAPA) was identified by isotopic analysis (18O,15N) and further proved by trapping α‐CAPA with nucleophiles such as water, amino acids, phosphate and methanol in alkaline media, which yieldedN‐phosphoamino acids and peptide phosphoanhydride and phosphate ester derivatives. By comparison with the reactivity of NCAs, the bielectrophilicity of CAPAs indicates that CAPAs can provide rich chemistry.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis and Biological Evaluation of Non‐Hydrolyzable 1,2,3‐Triazole‐Linked Sialic Acid Derivatives as Neuraminidase Inhibitors (Eur. J. Org. Chem. 16/2009)
Authors: Weïwer Michel , Chen Chi‐Chang , Kemp Melissa M. , Linhardt Robert J. 
Published: May 2009

AbstractThe cover picture shows the binding of an influenza virus to the surface of a host cell. The hemaglutinin (blue spikes) binds to the sialic acid (green hexagons) residues present on the non‐reducing end of the surface glycoprotein to gain entry into the cell. Once the cell is infected, the viral neuraminidases (pink pinwheels) cleave the sialic acids to escape. The 1,2,3‐triazole‐linked sialic acid derivatives (green spheres) were designed to act as non‐hydrolyzable inhibitors to block the virus. Details are discussed in the article by R. J. Linhardt et al. on p. 2611 ff.
Bismuth Modified Gold Microelectrode for Pb(II) Determination in Wine Using Alkaline Medium
Authors: Oliveira Salles Maiara , Ruas de Souza Ana Paula , Naozuka Juliana , de Oliveira Pedro Vitoriano , Bertotti Mauro 
Published: May 2009

AbstractElectrodeposition of bismuth on gold microelectrodes for determination of Pb(II) by square wave anodic stripping voltammetry (SWASV) was accomplished by an in situ procedure in alkaline solution. A linear calibration plot for Pb(II) in the concentration range 40 to 6700 nmol L−1 (r=0.998) was obtained, the detection limit was found to be 12.5 nmol L−1 (S/N=3) and the relative standard deviation in solutions containing 1 μmol L−1 Pb(II) was 4% (n=12). The analytical performance of the proposed sensor was tested by measuring the Pb(II) concentration in a wine sample. The result was in good agreement with the one obtained by GFAAS.
Electrodeposited Silver Nanoparticles on Carbon Ionic Liquid Electrode for Electrocatalytic Sensing of Hydrogen Peroxide
Authors: Safavi Afsaneh , Maleki Norouz , Farjami Elaheh 
Published: May 2009

AbstractSilver nanoparticles (narrowly dispersed in diameter) were electrodeposited on carbon ionic liquid electrode (CILE) surface using a two‐step potentiostatic method. Potentiostatic double pulse technique was used as a suitable and simple method for controlling the size and morphologies of silver nanoparticles electrodeposited on CILE. The obtained silver nanoparticles deposited on CILE surface showed excellent electrocatalytic activity (low overpotential of −0.35 V vs. Ag/AgCl) towards reduction of hydrogen peroxide. A linear dynamic range of 2–200 μM with an experimental detection limit of 0.7 μM (S/N=3) and reproducibility of 4.1% (n=5) make the constructed sensor suitable for peroxide determination in aqueous solutions.
Electrochemical Aptasensors – Recent Achievements and Perspectives
Authors: Hianik Tibor , Wang Joseph 
Published: May 2009

AbstractThis article reviews recent achievements in developing aptamer‐based electrochemical biosensors (electrochemical aptasensors). Aptamers are single stranded DNA or RNA molecules with high specificity to various ligands. Their specificity is comparable and in certain cases even higher than those of antibodies. In contrast to antibodies, aptamers are prepared by an in vitro selection procedure developed simultaneously in the early 1990s by L. Gold and A. Ellington. Due to their stability and the possibility of chemical modification aptamers can be immobilized on various supports and serve as artificial receptors in biosensors. The first aptasensors developed in the second half of 1990s were based on optical detection. However, in early 2000 substantial interest arose to the development of electrochemical aptasensors. It has been shown that due to their simplicity and fast response they represent an excellent tool in practical applications. The main focus of this review is to discuss the configuration of aptamers and electrochemical methods for detecting aptamers–analyte interactions. We will also provide a brief history of aptamer development, along with molecular structure and methods of aptamer engineering. Methods for immobilizing aptamers onto a solid support are also discussed.
Electroanalysis of Norepinephrine at Bare Gold Electrode Pure and Modified with Gold Nanoparticles and S‐Functionalized Self‐Assembled Layers in Aqueous Solution
Authors: Łuczak Teresa 
Published: May 2009

AbstractGold nanoparticles (Au‐NPs), cystamine (CA) and 3,3′‐dithiodipropionic acid (DTDPA) modified gold bare electrodes were applied in voltammetric sensors for simultaneous detection of norepinephrine (NEP), ascorbic (AA) and uric (UA) acids. A linear relationship between norepinephrine concentration and current response was obtained in the range of 0.1 μM to 600 μM M with the detection limit ≤0.091 μM for the electrodes modified at 2D template and in the range of 0.1 μM to 700 μM M with the detection limit ≤0.087 μM for the electrodes modified at 3D template The results have shown that using modified electrodes it is possible to perform electrochemical analysis of norepinephrine without interference of ascorbic and uric acids, whose presence is the major limitation in norepinephrine determination at a bare gold electrode. The modified SAMs electrodes show good selectivity, sensitivity, reproducibility and high stability.
Performance analysis of random uniform power allocation for wireless networks in Rayleigh fading channels
Authors: Elmusrati Mohammed , Tarhuni Naser , Jäntti Riku 
Published: May 2009

AbstractWhen there is no feedback channels in wireless sensor networks or when the sensors are deaf (cannot listen to the feedback channels), the conventional and practical method for power allocation is to use fixed power transmission. This method has many limitations such as near–far problems where the relatively far away sensors are blocked by near sensors and also the unnecessarily high power consumption for good channel sensors. One recent proposal to overcome such limitations is to use uniform random power allocation for terminals. In that work the system performance is analysed for static channels (i.e. snapshot assumption), where it shows that there is a considerable obtained gain when using uniform random power allocation over fixed power. An important question is about the performance of such transmission power strategy in case of a more realistic channel scenario such as Rayleigh fading channels. This paper answers this question. Detailed mathematical analysis as well as Monte‐Carlo simulations for the system performance in Rayleigh fading channels are given in this paper. We show that the performance of uniform power allocation is much worse in case of fading channels than in static channels. Almost there is no gain of using uniform random power over fixed power in terms of average probability of outage. However, uniform random power may considerably reduce the total power consumption at small degradation of the average performance. This can be critical feature in energy constrained networks. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling multi‐stage decomposition of cotton fabrics considering char oxidation in the presence of oxygen
Authors: Zhu F. L. , Wang X. J. , Cheng X. P. , Ma S. Q. 
Published: May 2009

AbstractA theoretical model, describing thermal degradation behavior of cotton fabrics that exposed to a constant radiant heat flux, is proposed in the paper. The model describes thermal and oxidative degradation of cotton fabric under the oxygen‐containing atmosphere and considers pseudo‐bi‐component separate‐stage kinetic process. Both exothermic and endothermic reactions are included in the decomposition process. At present, gas phase oxidation reactions are not included. Comparison with experimental results demonstrates that the predictions of the mass loss rate and temperature profile with these cotton fabrics are in agreement with the experiment. Effects of thermal radiation and ambient oxygen concentration on decomposition have also been investigated. The gas phase temperature is also predicted by the present numerical model. Results from numerical model will help contribute to a better understanding of the ignition mechanism of flame‐resistant cotton fabrics used for fire safety garments. Copyright © 2009 John Wiley & Sons, Ltd.
Aerodynamic shape optimization on overset grids using the adjoint method
Authors: Liao Wei , Tsai Her Mann 
Published: May 2009

AbstractThis paper deals with the use of the continuous adjoint equation for aerodynamic shape optimization of complex configurations with overset grids methods. While the use of overset grid eases the grid generation process, the non‐trivial task of ensuring communication between overlapping grids needs careful attention. This need is effectively addressed by using a practically useful technique known as the implicit hole cutting (IHC) method. The method depends on a simple cell selection process based on the criterion of cell size, and all grid points including interior points and fringe points are treated indiscriminately in the computation of the flow field. This paper demonstrates the simplicity of the IHC method for the adjoint equation. Similar to the flow solver, the adjoint equations are solved on conventional point‐matched and overlapped grids within a multi‐block framework. Parallel computing with message passing interface is also used to improve the overall efficiency of the optimization process. The method is successfully demonstrated in several two‐ and a three‐dimensional shape optimization cases for both external and internal flow problems. Copyright © 2009 John Wiley & Sons, Ltd.
Nanostructured Electrodes and Gel‐Polymer Electrolyte for an Improved Li‐ion Battery
Authors: Penazzi N. , Bodoardo S. , Bongiovanni R. , Gerbaldi C. , Meligrana G. , Mulas G. , Nair J. 
Published: May 2009

AbstractThe present communication deals with the results obtained by the electrochemistry research group at the Politecnico di Torino in Italy in the field of materials for Li‐ion cells. Cathode (LiFePO4/C powder), anode (Ni3Sn4–C alloy) and electrolyte (gel‐polymer membrane) cell components have been prepared with the aim of obtaining, beyond high performance, cheap materials from easily disposable reagents via simple and reliable preparations.
Case‐only genome‐wide interaction study of disease risk, prognosis and treatment
Authors: Pierce Brandon L. , Ahsan Habibul 
Published: May 2009

AbstractCase‐control genome‐wide association (GWA) studies have facilitated the identification of susceptibility loci for many complex diseases; however, these studies are often not adequately powered to detect gene‐environment (G×E) and gene‐gene (G×G) interactions. Case‐only studies are more efficient than case‐control studies for detecting interactions and require no data on control subjects. In this article, we discuss the concept and utility of the case‐only genome‐wide interaction (COGWI) study, in which common genetic variants, measured genome‐wide, are screened for association with environmental exposures or genetic variants of interest. An observed G‐E (or G‐G) association, as measured by the case‐only odds ratio (OR), suggests interaction, but only if the interacting factors are unassociated in the population from which the cases were drawn. The case‐only OR is equivalent to the interaction risk ratio. In addition to risk‐related interactions, we discuss how the COGWI design can be used to efficiently detect G×G, G×E and pharmacogenetic interactions related to disease outcomes in the context of observational clinical studies or randomized clinical trials. Such studies can be conducted using only data on individuals experiencing an outcome of interest or individuals not experiencing the outcome of interest. Sharing data among GWA and COGWI studies of disease risk and outcome can further enhance efficiency. Sample size requirements for COGWI studies, as compared to case‐control GWA studies, are provided. In the current era of genome‐wide analyses, the COGWI design is an efficient and straightforward method for detecting G×G, G×E and pharmacogenetic interactions related to disease risk, prognosis and treatment response. Genet. Epidemiol. 34:7–15, 2010. © 2009 Wiley‐Liss, Inc.
Shrinkage estimation for robust and efficient screening of single‐SNP association from case‐control genome‐wide association studies
Authors: Luo Sheng , Mukherjee Bhramar , Chen Jinbo , Chatterjee Nilanjan 
Published: May 2009

AbstractPopulation‐based case‐control design has become one of the most popular approaches for conducting genome‐wide association scans for rare diseases like cancer. In this article, we propose a novel method for improving the power of the widely used single‐single‐nucleotide polymorphism (SNP) two‐degrees‐of‐freedom (2 d.f.) association test for case‐control studies by exploiting the common assumption of Hardy‐Weinberg Equilibrium (HWE) for the underlying population. A key feature of the method is that it can relax the assumed model constraints via a completely data‐adaptive shrinkage estimation approach so that the number of false‐positive results due to the departure of HWE is controlled. The method is computationally simple and is easily scalable to association tests involving hundreds of thousands or millions of genetic markers. Simulation studies as well as an application involving data from a real genome‐wide association study illustrate that the proposed method is very robust for large‐scale association studies and can improve the power for detecting susceptibility SNPs with recessive effects, when compared to existing methods. Implications of the general estimation strategy beyond the simple 2 d.f. association test are discussed. Genet. Epidemiol. 33:740–750, 2009. Published 2009 Wiley‐Liss, Inc.
Avoiding the high Bonferroni penalty in genome‐wide association studies
Authors: Gao Xiaoyi , Becker Lewis C. , Becker Diane M. , Starmer Joshua D. , Province Michael A. 
Published: May 2009

AbstractA major challenge in genome‐wide association studies (GWASs) is to derive the multiple testing threshold when hypothesis tests are conducted using a large number of single nucleotide polymorphisms. Permutation tests are considered the gold standard in multiple testing adjustment in genetic association studies. However, it is computationally intensive, especially for GWASs, and can be impractical if a large number of random shuffles are used to ensure accuracy. Many researchers have developed approximation algorithms to relieve the computing burden imposed by permutation. One particularly attractive alternative to permutation is to calculate the effective number of independent tests, Meff, which has been shown to be promising in genetic association studies. In this study, we compare recently developed Meff methods and validate them by the permutation test with 10,000 random shuffles using two real GWAS data sets: an Illumina 1M BeadChip and an Affymetrix GeneChip® Human Mapping 500K Array Set. Our results show that the simpleM method produces the best approximation of the permutation threshold, and it does so in the shortest amount of time. We also show that Meff is indeed valid on a genome‐wide scale in these data sets based on statistical theory and significance tests. The significance thresholds derived can provide practical guidelines for other studies using similar population samples and genotyping platforms. Genet. Epidemiol. 34:100–105, 2010. © 2009 Wiley‐Liss, Inc.
Neural correlates of exemplar novelty processing under different spatial attention conditions
Authors: Stoppel Christian Michael , Boehler Carsten Nicolas , Strumpf Hendrik , Heinze Hans‐Jochen , Hopf Jens Max , Düzel Emrah , Schoenfeld Mircea Ariel 
Published: May 2009

AbstractThe detection of novel events and their identification is a basic prerequisite in a rapidly changing environment. Recently, the processing of novelty has been shown to rely on the hippocampus and to be associated with activity in reward‐related areas. The present study investigated the influence of spatial attention on neural processing of novel relative to frequently presented standard and target stimuli. Never‐before‐seen Mandelbrot‐fractals absent of semantic content were employed as stimulus material. Consistent with current theories, novelty activated a widespread network of brain areas including the hippocampus. No activity, however, could be observed in reward‐related areas with the novel stimuli absent of a semantic meaning employed here. In the perceptual part of the novelty‐processing network a region in the lingual gyrus was found to specifically process novel events when they occurred outside the focus of spatial attention. These findings indicate that the initial detection of unexpected novel events generally occurs in specialized perceptual areas within the ventral visual stream, whereas activation of reward‐related areas appears to be restricted to events that do possess a semantic content indicative of the biological relevance of the stimulus. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Dysregulation of working memory and default‐mode networks in schizophrenia using independent component analysis, an fBIRN and MCIC study
Authors: Kim Dae Il , Manoach Dara S. , Mathalon Daniel H. , Turner Jessica A. , Mannell Maggie , Brown Greg G. , Ford Judith M. , Gollub Randy L. , White Tonya , Wible Cynthia , Belger Aysenil , Bockholt H.Jeremy , Clark Vince P. , Lauriello John , O'Leary Daniel , Mueller Bryon A. , Lim Kelvin O. , Andreasen Nancy , Potkin Steve G. , Calhoun Vince D. 
Published: May 2009

AbstractDeficits in working memory (WM) are a consistent neurocognitive marker for schizophrenia. Previous studies have suggested that WM is the product of coordinated activity in distributed functionally connected brain regions. Independent component analysis (ICA) is a data‐driven approach that can identify temporally coherent networks that underlie fMRI activity. We applied ICA to an fMRI dataset for 115 patients with chronic schizophrenia and 130 healthy controls by performing the Sternberg Item Recognition Paradigm. Here, we describe the first results using ICA to identify differences in the function of WM networks in schizophrenia compared to controls. ICA revealed six networks that showed significant differences between patients with schizophrenia and healthy controls. Four of these networks were negatively task‐correlated and showed deactivation across the posterior cingulate, precuneus, medial prefrontal cortex, anterior cingulate, inferior parietal lobules, and parahippocampus. These networks comprise brain regions known as the default‐mode network (DMN), a well‐characterized set of regions shown to be active during internal modes of cognition and implicated in schizophrenia. Two networks were positively task‐correlated, with one network engaging WM regions such as bilateral DLPFC and inferior parietal lobules while the other network engaged primarily the cerebellum. Our results suggest that DLPFC dysfunction in schizophrenia might be lateralized to the left and intrinsically tied to other regions such as the inferior parietal lobule and cingulate gyrus. Furthermore, we found that DMN dysfunction in schizophrenia exists across multiple subnetworks of the DMN and that these subnetworks are individually relevant to the pathophysiology of schizophrenia. In summary, this large multsite study identified multiple temporally coherent networks, which are aberrant in schizophrenia versus healthy controls and suggests that both task‐correlated and task‐anticorrelated networks may serve as potential biomarkers. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Apolipoprotein B100 acts as a molecular link between lipid-induced endoplasmic reticulum stress and hepatic insulin resistance #
Authors: Su Qiaozhu , Tsai Julie , Xu Elaine , Qiu Wei , Bereczki Erika , Santha Miklos , Adeli Khosrow 
Published: May 2009

Abstract
Accumulation of unfolded and misfolded proteins in the endoplasmic reticulum (ER) results in ER stress and lipid overload-induced ER stress has been implicated in the development of insulin resistance. Here, evidence is provided for a molecular link between hepatic apolipoprotein B100 (apoB100), induction of ER stress, and attenuated insulin signaling. First, in vivo upregulation of hepatic apoB100 by a lipogenic diet was found to be closely associated with ER stress and attenuated insulin signaling in the liver. Direct in vivo overexpression of human apoB100 in a mouse transgenic model further supported the link between excessive apoB100 expression and hepatic ER stress. Human apoB100 transgenic mice exhibited hypertriglyceridemia and hyperglycemia. In vitro, accumulation of cellular apoB100 by free fatty acid (oleate) stimulation or constant expression of wild-type or N-glycosylation mutant apoB50 in hepatic cells induced ER stress. This led to perturbed activation of glycogen synthase kinase 3 and glycogen synthase by way of the activation of c-Jun N-terminal kinase and suppression of insulin signaling cascade, suggesting that dysregulation of apoB was sufficient to disturb ER homeostasis and induce hepatic insulin resistance. Small interfering (si)RNA-mediated attenuation of elevated apoB level in the apoB50-expressing cells rescued cells from lipid-induced ER stress and reversed insulin insensitivity. Conclusion: These findings implicate apoB100 as a molecular link between lipid-induced ER stress and hepatic insulin resistance. (Hepatology 2009.)