bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equivalent circuits for repeater antennas used in wireless power transfer via magnetic resonance coupling
Authors: Imura Takehiro 
Published: January 2013

AbstractThe demand for wireless power transfer via magnetic resonance coupling is increasing. Magnetic resonance coupling is a new technology that achieves power transfers across a large air gap by using transmitting and receiving antennas. However, repeater antennas can enable power transmission across an even larger distance. These repeater antennas without cross coupling can be expressed as a T‐type equivalent circuit. Equivalent circuits that include cross coupling and mutual inductance, which is related to the antenna position, have not been studied. In this paper, a novel way to represent a repeater antenna by an equivalent circuit and a way to determine the mutual inductance are proposed and veriﬁed by performing an electromagnetic ﬁeld analysis and experiment. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(1): 51–62, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22360
Molecular Imprint for Electrochemical Detection of Streptomycin Residues Using Enzyme Signal Amplification
Authors: Que Xiaohua , Liu Bingqian , Fu Libing , Zhuang Junyang , Chen Guonan , Tang Dianping 
Published: January 2013

AbstractWe have designed a new molecularly imprinted co‐polymer (MIP) for the sensitive detection of streptomycin (STR) in food using enzymes as signal amplification. The MIP was fabricated via co‐polymerization of aniline and o‐phenylenediamine on gold substrate in the presence of STR as template. The assay is based on competitive binding of free STR and glucose oxidase‐labeled STR (GOx‐STR) to the imprinters on the MIP. On addition of glucose, hydrogen peroxide is formed that is detected by differential pulse voltammetry. Under optimal conditions, the decrease of the catalytic current is proportional to the STR concentration in the range from 0.01 to 10 ng mL−1, with a detection limit (LOD) of 7.0 pg mL−1 STR (at 3sB). Intra‐ and inter‐assay coefficients of variation (CVs) are<10.5 %. The system was further validated and evaluated with STR‐spiked samples including honey and milk, and the recovery was between 82 and 124.2 %.
Voltammetric Quantification of Zn and Cu, Together with Hg and Pb, Based on a Gold Microwire Electrode, in a Wider Spectrum of Surface Waters
Authors: Alves Georgina M. S. , Magalhães Júlia M. C. S. , Soares Helena M. V. M. 
Published: January 2013

AbstractThe simultaneous determination of Zn and Cu by anodic stripping voltammetry (ASV) is prone to errors due to the formation of Cu‐Zn intermetallic compounds. The main aim of this work was to study the possibility of simultaneous determination of Zn and Cu, together with Hg and Pb, using a mercury‐free solid gold microwire electrode. The multi‐element detection was carried out by differential pulse anodic stripping voltammetry (DPASV), in a chloride medium (0.5 M NaCl) under moderate acid conditions (HCl 1.0 mM) in the presence of oxygen, where the gold microwire electrode was used as stationary or vibrating working electrode during the deposition step. Under these conditions, no formation of Cu‐Zn intermetallic compounds were found for concentrations usually determined in surface waters. In addition, quantification of Zn and Cu, together with Hg and Pb, can be performed in a wide range of concentrations (about two orders of magnitude) using the same sample, in a very short period of time. The detection limits for Cu, Hg, Pb and Zn, using a vibrating electrode and 30 s of deposition time, were 0.2 µg L−1 for Hg, 0.3 µg L−1 for Pb and 0.4 µg L−1 for Zn and Cu, respectively. The proposed DPASV methods were successfully applied to the determination of Cu, Hg, Pb, and Zn in a certified reference fresh water, river, tap and coastal sea waters. These results proved the applicability and versatility of the proposed methods for the analysis of different water matrices and showed that a gold microwire electrode is a suitable choice to determine simultaneously Zn and Cu.
Zinc Detection in Serum by Anodic Stripping Voltammetry on Microfabricated Bismuth Electrodes
Authors: Jothimuthu Preetha , Wilson Robert A. , Herren Josi , Pei Xing , Kang Wenjing , Daniels Rodney , Wong Hector , Beyette Fred , Heineman William R. , Papautsky Ian 
Published: January 2013

AbstractZinc (Zn) homeostasis is required for a functional immune system. Critically ill patients often exhibit decreased Zn serum concentrations and could potentially benefit from Zn supplementation as a therapeutic strategy. However, the conventional approaches to monitoring Zn are time consuming and costly. This work reports on detection of Zn by anodic stripping voltammetry (ASV) on bismuth electrodes in a microfabricated electrochemical cell. The working potential window of the electrodeposited bismuth film electrode was investigated by cyclic voltammetry, while square wave ASV was used for measuring Zn in acetate buffer and blood serum. Conditions critical to sensing, such as preconcentration potential, preconcentration time, and buffer pH, were optimized for Zn detection. The sensor was successfully calibrated with pH 6 acetate buffer in the physiologically‐relevant range of 5 µM to 50 µM Zn and exhibited well‐defined and highly repeatable peaks. The sensor was used to demonstrate measurement of Zn in blood serum digested in HCl. The results of this work show that Zn detection in serum is possible with smaller sample volumes (µL vs. mL) and faster turnaround time (hours vs. days) as compared with the conventional spectroscopic methods.
Electroanalytical Study of Methanol Oxidation and Oxygen Reduction at Carbon Nanohorns‐Pt Nanostructured Electrodes
Authors: Hamoudi Zéhira , Brahim Aïssa , El Khakani My Ali , Mohamedi Mohamed 
Published: January 2013

AbstractThis work reports a comprehensive electroanalytical study of carbon nanohorns (CNHs) in electrochemical applications. Compared to other types of carbons, the bare CNHs electrode exhibited higher peak current densities and lowest anodic peak‐to‐cathodic peak separation of less than 50 mV for the [Fe(CN)4−]6/[Fe(CN)3−]6 redox couple. Furthermore, CNHs exhibited excellent electrocatalyst supporting properties for porous Pt film towards methanol oxidation reaction reaching a peak current density of 127 mA cm−2 or peak current mass activity 184 mA mgPt−1. Regarding oxygen reduction reaction, an onset potential as positive as 0. 77 V vs. Ag/AgCl was achieved with CNHs/porous Pt film.
MicroRNAs in age‐related diseases
Authors: Dimmeler Stefanie , Nicotera Pierluigi 
Published: January 2013

AbstractAging is a complex process that is linked to an increased incidence of major diseases such as cardiovascular and neurodegenerative disease, but also cancer and immune disorders. MicroRNAs (miRNAs) are small non‐coding RNAs, which post‐transcriptionally control gene expression by inhibiting translation or inducing degradation of targeted mRNAs. MiRNAs target up to hundreds of mRNAs, thereby modulating gene expression patterns. Many miRNAs appear to be dysregulated during cellular senescence, aging and disease. However, only few miRNAs have been so far linked to age‐related changes in cellular and organ functions. The present article will discuss these findings, specifically focusing on the cardiovascular and neurological systems.This review is part of the small RNAs review series. See more reviews from this series. http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1757‐4684/homepage/reviews_smallrnas.htm
A refined aquatic ecological risk assessment for a pyrethroid insecticide used for adult mosquito management
Authors: Schleier Jerome J. , Peterson Robert K.D. 
Published: January 2013

Abstract
The use of pyrethroid insecticides has increased substantially throughout the world over the past few decades as the use of organophorous, carbamate, and organochlorine insecticides is being phased out. Pyrethroids are the most common class of insecticides for ultralow-volume (ULV) aerosol applications used to manage high densities of adult mosquitoes. Pyrethroids are highly toxic to nontarget organisms such as certain aquatic organisms, and there have been concerns about the effect of applications of ULV insecticides on these organisms. To address the uncertainties associated with the risks of ULV applications and the contradictory findings of other ecological risk assessments, the authors performed a probabilistic aquatic ecological risk assessment for permethrin using actual environmental deposition on surfaces to estimate permethrin concentrations in water. The present study is the first ecological risk assessment for pyrethroids to quantitatively integrate the reduction in bioavailability resulting from the presence of dissolved organic matter. As part of the risk assessment, the authors incorporated a species sensitivity distribution to take into account the differences in toxicity for different species. The 95th percentile estimated concentration would result in less than 0.0001% of the potentially affected fraction of species reaching the lethal concentration that kills 50% of a population. The results of the present study are supported by the weight of evidence that pyrethroids applied by ground-based ULV equipment will not result in deleterious effects on aquatic organisms. Environ. Toxicol. Chem. 2013;32:948–953. © 2013 SETAC
Toxicity of four sulfonamide antibiotics to the freshwater amphipod Hyalella azteca
Authors: Bartlett Adrienne J. , Balakrishnan V.K. , Toito J. , Brown L.R. 
Published: January 2013

Abstract
Sulfonamides are a widely used class of antibiotics; however, there are few toxicological data available with which to conduct environmental risk assessments for these compounds. Therefore, the toxicity of four sulfonamides (sulfaguanidine, sulfathiazole, sulfamerazine, and sulfasalazine) to Hyalella azteca was assessed in chronic (four-week), water-only exposures. Survival was evaluated weekly, and growth was measured at the end of the test. Four-week lethal concentrations associated with 50% mortality (LC50s) for sulfaguanidine, sulfathiazole, and sulfamerazine were 0.90, 1.6, and 3.9 µM, respectively. Sulfaguanidine caused effects on survival more quickly and at lower concentrations than sulfathiazole or sulfamerazine. These differences were more pronounced at week 1 than week 4, when sulfaguanidine LC50s were 8 to 20 times lower and 2 to 4 times lower, respectively. Growth was affected by sulfathiazole but was a less sensitive end point than survival, with an effective concentration associated with 50% reduction in growth (EC50) of 13 µM, whereas sulfaguanidine and sulfamerazine caused negligible effects on growth. Sulfasalazine had no effect on survival or growth at any concentration tested, up to 13 µM. The effects observed in the present study occurred at concentrations exceeding those typically found in environmental waters. However, given that LC50s decreased with exposure duration (except for sulfasalazine), the present study demonstrates the importance of conducting longer-term tests to adequately assess the environmental toxicity of sulfonamides. Environ. Toxicol. Chem. 2013;32:866–875. © 2013 SETAC
Silver nanoparticle toxicity effect on growth and cellular viability of the aquatic plant Lemna gibba
Authors: Oukarroum Abdallah , Barhoumi Lotfi , Pirastru Laura , Dewez David 
Published: January 2013

Abstract
The toxicity effect of silver nanoparticles (AgNPs) on growth and cellular viability was investigated on the aquatic plant Lemna gibba exposed over 7 d to 0, 0.01, 0.1, 1, and 10 mg/L of AgNPs. Growth inhibition was demonstrated by a significant decrease of frond numbers dependent on AgNP concentration. Under these conditions, reduction in plant cellular viability was detected for 0.1, 1, and 10 mg/L of AgNPs within 7 d of AgNPs treatment. This effect was highly correlated with the production of intracellular reactive oxygen species (ROS). A significant increase of intracellular ROS formation was triggered by 1 and 10 mg/L of AgNP exposure. The induced oxidative stress was related to Ag accumulation within L. gibba plant cells and with the increasing concentration of AgNP exposure in the medium. The authors' results clearly suggested that AgNP suspension represented a potential source of toxicity for L. gibba plant cells. Due to the low release capacity of free soluble Ag from AgNP dissolution in the medium, it is most likely that the intracellular uptake of Ag was directly from AgNPs, triggering cellular oxidative stress that may be due to the release of free Ag inside plant cells. Therefore, the present study demonstrated that AgNP accumulation in an aquatic environment may represent a potential source of toxicity and a risk for the viability of duckweeds. Environ. Toxicol. Chem. 2013;32:902–907. © 2013 SETAC
Toxic effects of environment-friendly antifoulant nonivamide on Phaeodactylum tricornutum
Authors: Zhou Jun , Yang Cuiyun , Wang Jianhua , Sun Pengcheng , Fan Ping , Tian Kai , Liu Sujing , Xia Chuanhai 
Published: January 2013

Abstract
Nonivamide, a synthetic derivate of natural capsaicin, has an effective antifouling activity. However, the poor understanding of the toxicity mechanism limits the application of nonivamide in antifouling paints. The present study investigated the inhibitory effects and toxicity mechanism of nonivamide on Phaeodactylum tricornutum. Under a 1.5 × 105 cells/ml of initial algal density (IAD), the effective concentration causing 50% inhibition at 4- d (4 d-EC50) value of nonivamide was 5.1 mg/L. Reactive oxygen species (ROS) level was significantly increased in nonivamide-treated algae. Algal antioxidants, including catalases (CAT), peroxidases (POD), superoxide dismutases (SOD), and glutathione (GSH), were all stimulated by the ROS burst. The excessive ROS substances led to the loss of algal photosynthetic pigments and also damage to the integrity of the lipid membrane. Furthermore, ROS-related genes, including psbA, psbD, psaB, rbcL, nad1, and cob, were found to be suppressed in the chloroplasts and mitochondria of nonivamide-treated algae, and the concentration of cytoplasmic Ca2+, an important regulator of chloroplast and mitochondrion, was elevated. The present study demonstrates that nonivamide could cause peroxidative damages to P. tricornutum by inducing ROS overproduction, which may be initiated by the suppression of ROS-related genes in algal chloroplasts and mitochondria. Environ. Toxicol. Chem. 2013;32:802–809. © 2013 SETAC
A finite volume cell‐centered Lagrangian hydrodynamics approach for solids in general unstructured grids
Authors: Sambasivan Shiv Kumar , Shashkov Mikhail J , Burton Donald E 
Published: January 2013

SUMMARYA finite volume cell‐centered Lagrangian hydrodynamics approach, formulated in Cartesian frame, is presented for solving elasto‐plastic response of solids in general unstructured grids. Because solid materials can sustain significant shear deformation, evolution equations for stress and strain fields are solved in addition to mass, momentum, and energy conservation laws. The total stress is split into deviatoric shear stress and dilatational components. The dilatational response of the material is modeled using the Mie‐Grüneisen equation of state. A predicted trial elastic deviatoric stress state is evolved assuming a pure elastic deformation in accordance with the hypo‐elastic stress‐strain relation. The evolution equations are advanced in time by constructing vertex velocity and corner traction force vectors using multi‐dimensional Riemann solutions erected at mesh vertices. Conservation of momentum and total energy along with the increase in entropy principle are invoked for computing these quantities at the vertices. Final state of deviatoric stress is effected via radial return algorithm based on the J‐2 von Mises yield condition. The scheme presented in this work is second‐order accurate both in space and time. The suitability of the scheme is evinced by solving one‐ and two‐dimensional benchmark problems both in structured grids and in unstructured grids with polygonal cells. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis and Self‐Assembly of Bolaamphiphiles Based on β‐Amino Acids or an Alcohol
Authors: Mainkar Prathama S. , Sridhar Chirumarry , Sudhakar Ambadi , Chandrasekhar Srivari 
Published: January 2013

AbstractThe synthesis of bolaamphiphiles from unusual β‐amino acids or an alcohol and C12 or C20 spacers is described. Unusual β‐amino acids such as a sugar amino acid, an AZT‐derived amino acid, a norbornene amino acid, and an AZT‐derived amino alcohol were coupled with spacers under standard conditions to get the novel bolaamphiphiles 5–8 (Scheme 1), 12 and 13 (Scheme 2), and 17 and 20 (Scheme 3). Some of these compounds, on precipitation from MeOH/H2O, self‐assembled into organized molecular structures.
Two New Sesquiterpenes from Euonymus alatus
Authors: Yan Zhao‐Hui , Han Zhu‐Zhen , Hu Xian‐Qing , Liu Qing‐Xin , Zhang Wei‐Dong , Liu Run‐Hui , Li Hui‐Liang 
Published: January 2013

AbstractTwo new sesquiterpenes, 1 and 2, as well as the five known compounds 3–7, were isolated from the stems of Euonymus alatus. Compounds 2–7 have a β‐dihydroagarofuran skeleton. The structures of these compounds were elucidated mainly by spectroscopic methods (1D‐, 2D‐NMR, ESI‐MS, and HR‐ESI‐MS). We also report the X‐ray crystal structure of evonine (3) for the first time.
Unexpected Approach to the Synthesis of 2‐Phenylquinoxalines and Pyrido[2,3‐b]pyrazines via a Regioselective Reaction
Authors: Alizadeh Abdolali , Mokhtari Javad 
Published: January 2013

AbstractAn unexpected approach to the preparation of quinoxaline and pyrido[2,3‐b]pyrazine derivatives 5 is described. The reaction between 1H‐indole‐2,3‐diones 1, 1‐phenyl‐2‐(triphenylphosphoranylidene)ethanone (2), and benzene‐1,2‐ or pyridine‐2,3‐diamines 3 proceeds in MeOH under reflux in good to excellent yields (Scheme 1 and Table). No co‐catalyst or activator is required for this multi‐component reaction (MCR), and the reaction is, from an experimental point of view, simple to perform. The structures of 5, 5′, and 6 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and were confirmed by comparison with reference compounds. A plausible mechanism for this type of reaction is proposed (Scheme 2).
Synthesis and Evaluation of Four Hederagenin Glycosides as α‐Glucosidase Inhibitor
Authors: Liu Qing‐Chao , Guo Tian‐Tian , Guo Shou‐Dong , Li Wen‐Hong , Li Dong 
Published: January 2013

AbstractThe four hederagenin glycosides 1–4 were efficiently synthesized through one‐pot sequential glycosylations with glycose 1‐(trichloroacetimidate)s as donors, resulting in a significantly simplified synthetic procedure without isolation of glycosylation intermediates. The activity of the synthetic hederagenin glycosides 1–4 against α‐glucosidase type IV was evaluated; hederagenin glycoside 4 containing an α‐L‐rhamnopyranosyl unit showed the best activity with an IC50 value of 47.9 μM.
Prenylated Benzene Metabolites from Melicope pteleifolia
Authors: Yang Li‐Jun , Jiang Kun , Tan Jun‐Jie , Qu Shi‐Jin , Luo Hong‐Feng , Tan Chang‐Heng , Zhu Da‐Yuan 
Published: January 2013

AbstractChemical investigation on the stem and root of Melicope pteleifolia afforded three new prenylated benzene metabolites as racemic mixtures, named pteleifolins A–C (1–3, resp.). Their gross structures were elucidated on the basis of spectroscopic analysis, especially 2D‐NMR experiments. An enantiomer resolution of (±)‐1 using chiral HPLC was performed, and the absolute configuration of the enantiomers were determined to be (+)‐(S)‐1 and (−)‐(R)‐1 by means of circular‐dichroism analysis.
Isoindolones from Lasiosphaera fenzliiReich. and Their Bioactivities
Authors: Lü Wen‐Wen , Gao Yun‐Jia , Su Ming‐Zhi , Luo Zhou , Zhang Wei , Shi Guo‐Bing , Zhao Qing‐Chun 
Published: January 2013

AbstractTwo new, 1 and 2, along with one known isoindolone, 3, were isolated from the AcOEt extract of Lasiosphaera fenzlii Reich. The structures of these compounds were determined as 4,6‐dihydroxy‐1H‐isoindole‐1,3(2H)‐dione (1), 4,6‐dihydroxy‐2,3‐dihydro‐1H‐isoindol‐1‐one (2), and clitocybin A (3) on the basis of chemical and spectroscopic evidences. The bioactivity assays revealed that all of them were devoid of significant cytotoxicities against tumor cells, whereas 1 exhibited potent antiangiogenic activity by inhibiting the secretion of vascular endothelial growth factor (VEGF) in A549 cells.
Operation mechanism of FoF1‐adenosine triphosphate synthase revealed by its structure and dynamics
Authors: Iino Ryota , Noji Hiroyuki 
Published: January 2013

AbstractFoF1‐Adenosine triphosphate (ATP) synthase, a complex of two rotary motor proteins, reversibly converts the electrochemical potential of protons across the cell membrane into phosphate transfer potential of ATP to provide the energy currency of the cell. The water‐soluble motor is F1‐ATPase, which possesses ATP synthesis/hydrolysis catalytic sites. Isolated F1 hydrolyses ATP to rotate the rotary shaft against the stator ring. The membrane‐embedded motor is Fo, which is driven by proton flow down the proton electrochemical potential. In the FoF1 complex, the direction of mechanical rotation, the chemical reaction, and the proton transport are determined by the relative amplitudes between the Gibbs free energy of the ATP hydrolysis reaction and the electrochemical potential of protons across the membrane. Therefore, FoF1‐ATP synthase is a highly efficient molecular device in which the chemical, mechanical, and potential energies are tightly and reversibly converted. In this critical review, we summarize our latest knowledge about the operation mechanism of this sophisticated nanomachine, revealed by its structure and dynamics. © 2013 IUBMB Life, 65(3):238–246, 2013.
What is the nature of the mitochondrial permeability transition pore and What is it Not?
Authors: Siemen Detlef , Ziemer Mirjam 
Published: January 2013

AbstractSince about 60 years a phenomenon now called permeability transition is known in mitochondria. It involves a large pore in the inner mitochondrial membrane, the permeability transition pore (PTP) whose molecular structure is still unknown. Year after year, new hypotheses have been developed how this pore could look like and which proteins cold be structural elements. Enormous progress was made in understanding function, rich pharmacology, and possible biochemical modulation of the PTP. However, many of the structural hypotheses that seemed to be well established by experiments had to be rejected later after their falsification by further experiments. The aim of this review is to give a brief insight into confirmed and less known details of the nature of the pore and of its function. Thereafter, this review will critically report about some of the unknown elements and hypotheses that had to be rejected. © 2013 IUBMB Life, 65(3):255–262, 2013.