bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Oxidation of Cytosine on Carbon Paste Electrode and Its Determination
Authors: Ruan Cheng‐Xiang , Lou Jin , Duan Yuan‐Yuan , Sun Wei 
Published: May 2015

AbstractIn this paper electrochemical oxidation of cytosine was investigated on a carbon paste electrode for the first time. In pH 5.0 Britton‐Robinson (B‐R) buffer solution a well‐define irreversible oxidation peak appeared at the potential of 1.480 V (vs. SCE), which indicated the electrooxidation of cytosine on the electrode. The electrochemical behaviors of cytosine were carefully investigated by cyclic voltammetry at the selected conditions. The electrochemical parameters such as electron transfer number (n), electron transfer coefficient (α) and electrode reaction standard rate constant (ks) was calculated with the results as 2.14, 0.15 and 1.049 × 10−3 s−1, respectively. Under the optimal conditions a good linear relationship was constructed between the cytosine concentration and the differential pulse voltammetric current in the range from 10.0 to 1000.0 μmol/L with the linear regression equation as Ip(μA) = 0.0519C (μmol/L) + 0.419 (γ = 0.999) and the detection limit as 1.9 μmol/L (3σ;).
Fabrication of Cetyltrimethylammonium Bromide/chitosan Modified Glassy Carbon Electrode for Simultaneous Determination of Uric Acid and Ascorbic Acid
Authors: Zhang Ying , Luo Li‐Qiang , Ding Ya‐Ping , Li Qiu‐Xia , Shen Xia 
Published: May 2015

AbstractThe electrochemical behavior of uric acid (UA) and ascorbic acid (AA) on the surface of the cetyltrimethylammonium bromide (CTAB) incorporating chitosan film‐modified glassy carbon electrode (GCE) was investigated by linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV). The modified electrode could completely separate the common merged voltammetric signals of UA and AA for 204 mV. Under the optimum conditions, the anodic peak currents of DPV were proportional to the concentration of AA in the range of 2.0 to 800.0 μM, and that of UA in the range of 0.5 to 200.0 μM. The proposed method was used to detect UA in urine with a satisfactory result.
A Validated RP HPLC Method for Estimation of Almotriptan Malate in Pharmaceutical Dosage Form
Authors: Suneetha A. , Syama B. Sundar 
Published: May 2015

AbstractAn accurate, sensitive, precise and robust reverse phase high performance liquid chromatographic method for the estimation of almotriptan malate in pharmaceutical dosage form has been developed and validated. Chromatographic separation was conducted on Phenomenex Gemini C18 (250 mm × 4.6 mm, 5μ) column at room temperature using potassium dihydrogen phosphate buffer: acetonitrile (80:20) as a mobile phase, pH adjusted to 3.2 ± 0.1 with 10% sodium hydroxide and at a flow rate of 1.5 mL min−1, while UV detection was performed at 227 nm. The retention time for almotriptan malatewas found to be 9.47 ± 0.05 min. The method was found to be linear in the range of 1.0–10.0 μg mL−1. The limit of detection and quantitation for almotriptan malate were found to be 0.03 and 0.1 μg mL−1, respectively. Analytical recovery was > 99.87%. The method was validated stastically and applied for the quantitative analysis of almotriptan malate in bulk and formulations.
New Ruthenium(II) Polypyridyl‐Type Complexes with Oxadiazole Derivative Ligand
Authors: Lin Chien‐Ho , Kao Hsien‐Chang , Hsu Chia‐Jung , Wang Wen‐Jwu 
Published: May 2015

AbstractA new ruthenium complex, [Ru(L)(bpy)2]ṁ2PF6, (L = 3,5‐di(2ṁ‐pyridyl)‐1,2,4‐oxadiazole), was synthesized and characterized. The assignment of chemical shift for [Ru(L)(bpy)2]ṁ2PF6 was accomplished by HHCOSY technique. The cyclic voltammogram of [Ru(L)(bpy)2]ṁ2PF6 shows a metal‐centered RuII/RuII oxidation with potential at 1.35 V, as well as four reversible reduction waves with the former two potentials at −1.24 and −1.60 V, attributed to two bpy/bpy− process, and the latter two potentials at −1.86 and −2.16 V, attributed to L/L− and L−/L2−, respectively. The absorption spectrum of the ruthenium complex was dominated by metal‐to‐ligand charge transfer (MLCT) band in the visible range, with absorption maxima appearing at 442 nm and molar extinction coefficient of 13 × 103 M−1cm−1. The phosphorescent emission band has been attributed to from MLCT triplet state.
Electronic Structure of Anthocyanidins Adsorbed on Buckminsterfullerene: First Principles Studies
Authors: Su Yen Hsun , Wu Yang‐Kai , Hsue Young‐Chung 
Published: May 2015

AbstractThe efficiency of photoelectric conversion for environmentally‐friendly green solar cell, such as anthocyanidins‐sensitized solar cell, is low. Recently, fullerene‐based solar cell is used to improve efficiency of photo‐electric conversion. The evaluation of formation for the buckminsterfullerene (C60)‐anthocyanins system is desired. We use an inexpensive and low‐cost method tool, density functional theory, to study the buckminsterfullerene (C60)‐ anthocyanidins system. We found formation energy of C60 adsorbing anthocyanidins is ranged from −0.61 eV to −2.42 eV. Thus, compound of C60 and anthocyanidins may be synthesized by arc or laser power under reduction atmosphere. These phenomenons will have a potential to apply in the evaluation and database of anthocyanidins‐sensitized fullerene‐based solar cell.
Platinum Nanoparticles on Flexible Carbon Fiber Paper without Transparent Conducting Oxide Glass as Counter Electrode for Dye‐Sensitized Solar Cells
Authors: Lan Jo‐Lin , Feng Hsien‐Ping , Wei Tzu‐Chien , Peng Chao , Cheng Hai‐Peng , Chen Wen‐Hsiang , Chang Ya‐Huei , Hsu Wen‐Chi , Wan Chi‐Chao 
Published: May 2015

AbstractFlexible carbon fiber paper deposited with platinum nanoparticles was applied as counter electrode for dye‐sensitized solar cells (DSSCs). Compared to others, such as sputtered‐Pt or PVP‐capped Pt nanoparticles on TCO glass, not only does this counter electrode has good conductivity without using TCO glass but also flexible and shows good adhesion. Acceptable charge‐transfer resistance of 5.25 Ω‐cm2 is obtained. Current‐voltage characteristics of the DSSC are 0.71 V on VOC, 9.44 mA/cm2 on JSC, 0.61 on FF and 4.13% cell efficiency under AM 1.5, 100 mW/cm2 illumination. Additionally, spinning technology can be applied to produce this low cost counter electrode.
Tetrabutylammonium Fluoride (TBAF) Catalysed Synthesis of 2‐Arylbenzimidazole in Water under Ultrasound Irradiation
Authors: Joshi Ratnadeep S. , Mandhane Priyanka G. , Dabhade Sanjay K. , Gill Charansingh H. 
Published: May 2015

AbstractOne‐pot multistep reactions involving a new environmentally friendly catalytic procedure have been developed for the synthesis of benzimidazole. The reaction of the substituted aldehyde with o‐phenylenediamine in water under ultrasonic irradiation at ambient temperature for appropriate time using 5 mol% of TBAF furnish the desired product in good to excellent yield. The process is green, mild, inexpensive, excellent chemo selectivity, and excellent yields are the main advantages of this procedure.
Ionic Liquid‐Hemoglobin‐Carbon Paste Composite Bioelectrode and Its Electrocatalytic Activity
Authors: Xuan Zong‐Wei , Sun Xiao‐Ying , Jiao Guo‐Song , Zhai Zi‐Qin , Sun Wei , Lu Lu‐De 
Published: May 2015

AbstractA new carbon ionic liquid paste bioelectrode was fabricated by mixing hemoglobin (Hb) with graphite powder, ionic liquid 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF4) and liquid paraffin homogeneously. Nafion film was cast on the electrode surface to improve the stability of bioelectrode. Direct electrochemistry of Hb in the bioelectrode was carefully investigated. Cyclic voltammetric results indicated that a pair of well‐defined and quasi‐reversible electrochemical responses appeared in pH 7.0 phosphate buffer solution (PBS), indicating that direct electron transfer of Hb was realized in the modified electrode. The formal potential (E0′) was calculated as −0.316 V (vs. SCE), which was the typical characteristic of the electrochemical reaction of heme Fe(III)/Fe(II) redox couple. Based on the cyclic voltammetric results the electrochemical parameters of the electrode reaction were calculated. This bioelectrode showed high electrocatalytic activity towards the reduction of trichloroacetic acid (TCA) with good stability and reproducibility.
Thioglycolic Acid Capped CdS Quantum Dots as Fluorescence Probe for Ultrasensitive Determination of Tetracycline and Oxytetracycline
Authors: Zhao Shou‐Miao , Han Su‐Qin 
Published: May 2015

AbstractWater soluble CdS quantum dots (QDs) have been synthesized using thioglycolic acid (TGA) as surface modifying agent through a one step process by using safe and low cost materials. These TGA capped CdS QDs are highly stable in aqueous solution and applied for ultrasensitive tetracycline (TC) and oxytetracycline (OTC) sensing. The approach was based on the fluorescence of the QDs selectively quenched in the presence of TC and OTC, respectively. Under optimal conditions, the relative fluorescence intensities of CdS QDs were decreased linearly with increasing TC and OTC in the range of 0.05 to 10.0 μM and 0.1 to 10.0 μM, respectively. The limit of detection (S/N = 3) was 5.0 nM for TC and 10.0 nM for OTC, respectively. The RSD for eleven determinations of 5.0 μM TC was 1.26% and 5.0 μM OTC was 0.8%, respectively. There was no significant wavelength shift on the fluorescence‐quenched signals in the presence of the drugs. The effect of common foreign substances on the fluorescence of the QDs was examined to evaluate the selectivity and the results showed a high selectivity of the TGA capped CdS QDs towards TC and OTC. The method presented here is simple, rapid, inexpensive, sensitive and suitable for practical application.
Sensitive and Simple Electrochemical Detection of Lead(II) with Carbon Ionic Liquid Electrode
Authors: Liu He‐Jian , Qu Li‐Ning , Hu Song , Zhan Tian‐Rong , Zhao Chao‐Zhi , Sun Wei 
Published: May 2015

AbstractIn this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1‐ethyl‐3‐methylimidazolium ethylsulphate ([EMIM]EtOSO3) as the modifier and further used as the working electrode for the sensitive anodic stripping voltammetric detection of Pb2+. The characteristics of the CILE were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In pH 4.5 NaAc‐HAc buffer Pb2+ was accumulated on the surface of CILE due to the extraction effect of IL and reduced at a negative potential (‐1.20 V). Then the reduced Pb was oxidized by differential pulse anodic stripping voltammetry with an obvious stripping peak appeared at −0.67 V. Under the optimal conditions Pb2+ could be detected in the concentration range from 1.0 × 10−8 mol/L to 1.0 × 10−6 mol/L with the linear regression equation as Ip(μA) = −0.103 C (μmol/L) + 0.0376 (γ = 0.999) and the detection limit as 3.0 × l0−9 mol/L (3σ). Interferences from other metal ions were investigated and Cd2+ could be simultaneously detected in the mixture solution. The proposed method was further applied to the trace levels of Pb2+ detection in water samples with satisfactory results.
Markov model for characterizing neuropsychologic impairment and Monte Carlo simulation for optimizing efavirenz therapy
Authors: Bisaso Kuteesa R. , Mukonzo Jackson K. , Ette Ene I. 
Published: May 2015

AbstractThe study was undertaken to develop a pharmacokinetic‐pharmacodynamic model to characterize efavirenz‐induced neuropsychologic impairment, given preexistent impairment, which can be used for the optimization of efavirenz therapy via Monte Carlo simulations. The modeling was performed with NONMEM 7.2. A 1‐compartment pharmacokinetic model was fitted to efavirenz concentration data from 196 Ugandan patients treated with a 600‐mg daily efavirenz dose. Pharmacokinetic parameters and area under the curve (AUC) were derived. Neuropsychologic evaluation of the patients was done at baseline and in week 2 of antiretroviral therapy. A discrete‐time 2‐state first‐order Markov model was developed to describe neuropsychologic impairment. Efavirenz AUC, day 3 efavirenz trough concentration, and female sex increased the probability (P01) of neuropsychologic impairment. Efavirenz oral clearance (CL/F) increased the probability (P10) of resolution of preexistent neuropsychologic impairment. The predictive performance of the reduced (final) model, given the data, incorporating AUC on P01and CL /F on P10, showed that the model adequately characterized the neuropsychologic impairment observed with efavirenz therapy. Simulations with the developed model predicted a 7% overall reduction in neuropsychologic impairment probability at 450 mg of efavirenz. We recommend a reduction in efavirenz dose from 600 to 450 mg, because the 450‐mg dose has been shown to produce sustained antiretroviral efficacy.
A finite element method for modeling coupled flow and deformation in porous fractured media
Authors: Pouya Ahmad 
Published: May 2015

SummaryModeling the flow in highly fractured porous media by finite element method (FEM) has met two difficulties: mesh generation for fractured domains and a rigorous formulation of the flow problem accounting for fracture/matrix, fracture/fracture, and fracture/boundary fluid mass exchanges. Based on the recent theoretical progress for mass balance conditions in multifractured porous bodies, the governing equations for coupled flow and deformation in these bodies are first established in this paper. A weak formulation for this problem is then established allowing to build a FEM. Taking benefit from recent development of mesh‐generating tools for fractured media, this weak formulation has been implemented in a numerical code and applied to some typical problems of hydromechanical coupling in fractured porous media. It is shown that in this way, the FEM that has proved its efficiency to model hydromechanical phenomena in porous media is extended with all its performances (calculation time, couplings, and nonlinearities) to fractured porous media. Copyright © 2015 John Wiley & Sons, Ltd.
Abnormal functional connectivity in women with urgency urinary incontinence: Can we predict disease presence and severity in individual women using Rs‐fcMRI/
Authors: Nardos Rahel , Karstens Lisa , Carpenter Samuel , Aykes Kamari , Krisky Christine , Stevens Corrine , Gregory W.Thomas , Fair Damien A. 
Published: May 2015

AimsTo identify atypical brain functional connectivity in women with UUI and detrusor overactivity (DO) and to predict the presence/severity of UUI in individual women using connectivity features.MethodsThis is a cross‐sectional study comparing brain functional connectivity in women with and without UUI. Validated symptom/quality of life questionnaires were used for phenotyping. Participants are females between ages 40 and 85 with daily UUI with DO (Cases, N = 16) and without UUI (Controls, N = 24). Functional MRI and Resting state connectivity MRI were obtained at empty/ full bladder. Multivariate pattern analysis (MVPA) was used to predict the presence and severity of UUI from connectivity data.ResultsThere are significant differences in brain activation between cases and controls in eighteen brain regions irrespective of empty or full bladder. These include regions involved in attention (inferior partietal), decision making (inferior and superior frontal gyrus), primary motor and sensory (precentral and postcentral gyrus) functions. Women with UUI showed no change in connectivity with bladder filling in regions involved in interoception (insula), integration of afferent function (anterior cingulate), and decision making (middle frontal). MVPA of connectivity data showed robust classification of an individual woman as case or control (89% sensitivity, 83% specificity). Six connectivity features accurately predicted disease severity (R2 = 0.81).ConclusionWe identified two mechanisms of abnormal bladder control, one involving atypical activation of brain regions, and another atypical functional integration across sensory, emotional, cognitive and motor regions. Connectivity information is robust enough to classify an individual as having UUI or not and to predict symptom severity. Neurourol. Urodynam. 35:564–573, 2016. © 2015 Wiley Periodicals, Inc.
Springende Hüpfgummis
Authors: Vollmer Michael , Möllmann Klaus‐Peter 
Published: May 2015

AbstractHüpfgummis sind einfache, preiswerte Spielzeuge, die in Spielwarenläden oder Science Centern erhältlich sind. Sie ermöglichen interessante Einblicke in physikalische Phänomene der Mechanik – insbesondere mit Hochgeschwindigkeits‐Videos.
Circadian exosomal expression of renal thiazide‐sensitive NaCl cotransporter (NCC) and prostasin in healthy individuals
Authors: Castagna Annalisa , Pizzolo Francesca , Chiecchi Laura , Morandini Francesca , Channavajjhala Sarath Kiran , Guarini Patrizia , Salvagno Gianluca , Olivieri Oliviero 
Published: May 2015

PurposeA circadian timing system is involved in the maintenance of fluid and electrolyte balance and blood pressure control. Aldosterone and vasopressin modulate ion transporters and channels crucial in sodium (Na) and water reabsorption such as the epithelium Na channel and the renal thiazide‐sensitive NaCl cotransporter (NCC). We analyzed in urinary exosomes the intraday variations of NCC and prostasin expression and the association with electrolytes and water balance parameters.Experimental designBlood and urine samples were collected at five time points during the day from five healthy subjects. Blood renin, aldosterone, cortisol, ACTH, and plasmatic and urinary Na, potassium, creatinine, adiuretin (ADH), NCC, and prostasin were evaluated.ResultsACTH and cortisol showed a circadian pattern, similarly to aldosterone, while exosomal NCC and prostasin pattern were similar to urinary ADH, decreased in the morning and subsequently increased in the afternoon and evening.Conclusions and clinical relevanceIn urinary exosomes, NCC and prostasin had a diurnal pattern parallel to ADH and aquaporin 2, confirming that, in healthy subjects, both prostasin and NCC relate to water balance. These results provide suggestions for a possible chronotherapeutic approach in patients treated with thiazides, diuretic drugs acting as specific inhibitors of NCC‐mediated Na reabsorption.
A dynamic identity‐based user authentication scheme for remote login systems
Authors: Li Chun‐Ta , Lee Cheng‐Chi , Weng Chi‐Yao 
Published: May 2015

AbstractWith the purpose of accessing numerous network resources and services with user anonymity, various dynamic identity (ID)‐based user authentication schemes have been proposed. Recently, Khan et al. have pointed out the security weaknesses of the dynamic ID‐based user authentication scheme of Wang et al. and proposed an improved version of dynamic ID‐based user authentication scheme for remote login systems. They claimed that their scheme can withstand various security attacks and provide user anonymity. However, we found that the scheme of Khan et al. cannot preserve user anonymity if login message and system parameters are collected by the attacker. To ensure user anonymity, in this paper, we propose a new dynamic ID‐based user authentication scheme for remote login environments and the proposed scheme enables the user's real identity to mask periodically when the user logs into the remote server. Compared with the related schemes, the proposed scheme satisfies more admired criteria and it is suitable even for applications in low‐power computing environments. Finally, we formally prove the security of the proposed scheme by employing the Burrows–Abadi–Needham logic. Copyright © 2015 John Wiley & Sons, Ltd.
Pace mapping in the atrium using bipolar electrograms from widely spaced electrodes
Authors: Selvaraj Raja J. , Yerram Sreekanth , Kumar Pradeep , Satheesh Santhosh , Pillai Ajith Ananthakrishna , Saktheeswaran Mahesh Kumar , Balachander Jayaraman 
Published: May 2015

AbstractBackgroundPace mapping is a useful tool but is of limited utility for the atrium because of poor spatial resolution. We investigated the use of bipolar electrograms recorded from widely spaced electrodes in order to improve the resolution of pace mapping.MethodsThis prospective study included patients undergoing a clinical electrophysiology study. Unipolar pacing from either the superior or inferior lateral right atrium was performed to simulate atrial tachycardia. Twelve‐lead electrocardiograms were recorded during pacing as a template. In addition, three intracardiac bipolar electrograms from a set of widely spaced electrodes were also recorded. Subsequently, unipolar pacing was performed from electrodes at known distances from the initial pacing site, and the morphology of P waves in the electrocardiogram and bipolar electrograms were compared with that of the template. Morphological comparison was performed by a cardiologist and by automated computerized matching. Spatial resolution was calculated as the minimum distance at which there was no match.ResultsFifteen patients participated in the study. Distance at which differences in morphology were noted was smaller in the bipolar electrograms compared to that indicated by P waves in the electrocardiogram, when matched by the cardiologist (6.1±3.8 mm vs. 9.9±5.2 mm, p=0.012) or by automated analysis (4±0 mm vs. 9.9±4 mm, p<0.001).ConclusionsUse of three bipolar electrograms recorded from a set of widely spaced electrodes in the right atrium improves the resolution of pace mapping compared to that using P waves from surface electrocardiograms alone.
Firm performance in dynamic environments: The role of operational slack and operational scope
Authors: Kovach Jeremy J. , Hora Manpreet , Manikas Andrew , Patel Pankaj C. 
Published: May 2015

AbstractThis study examines the effects of operational scope (breadth of product offering, extent of geographical diversification, and extent to which production processes can effectively meet varying demand) and operational slack (resources in excess of what is required to fulfill expected demand) on firm performance, contingent on two components of a firm's dynamic environment, unpredictability and instability. We collate quarterly data on 3857 publicly traded firms in 19 industries from the years 1991 to 2013 (representing 99,559 firm‐quarter observations). Using panel data analysis, we find that narrow product offerings, low geographical diversification, low levels of excess capacity, and low inventory slack are each positively associated with firm performance. More importantly though, we find that operational scope is associated with improved performance in unpredictable environments, whereas operational slack is associated with improved performance in unstable environments. These findings contribute to the research on operations strategy by identifying the industry‐specific environmental conditions under which operational slack and operational scope are associated with firm performance.
¿Cómo elaborar una rúbrica?
Authors: Gatica-Lara Florina , Uribarren-Berrueta Teresita Del Niño Jesús 
Published: May 2015

La rúbrica es un instrumento de evaluación auténtica del desempeño de los estudiantes. En el presente documento se define y describe el proceso para elaborar las rúbricas, sus ventajas y desventajas. Además se listan algunas herramientas web para la creación de e-rúbricas.