bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multifunctional Organized Mesoporous Tin Oxide Films Templated by Graft Copolymers for Dye‐Sensitized Solar Cells
Authors: Park Jung Tae , Ahn Sung Hoon , Roh Dong Kyu , Lee Chang Soo , Kim Jong Hak 
Published: March 2014

AbstractThe synthesis of organized mesoporous SnO2 films with high porosity, larger pores, and good interconnectivity, obtained by sol–gel templating with an amphiphilic graft copolymer, poly(vinyl chloride)‐graft‐poly(oxyethylene methacrylate), is reported. An improved performance of dye‐sensitized solar cells (DSSCs) is demonstrated by the introduction of a 400 nm thick organized mesoporous SnO2 interfacial (om‐SnO2 IF) layer between nanocrystalline TiO2 (nc‐TiO2) and a fluorine‐doped tin oxide substrate. To elucidate the improved efficiency, the structural, optical, and electrochemical properties of the devices were characterized by SEM, UV/Vis spectroscopy, noncontact 3D surface profilometry, intensity‐modulated photocurrent/voltage spectroscopy, incident photon‐to‐electron conversion efficiency, and electrochemical impedance spectroscopy measurements. The energy‐conversion efficiency of the solid polymerized ionic liquid based DSSC fabricated with the om‐SnO2 IF/nc‐TiO2 photoanode reached 5.9 % at 100 mW cm−2; this is higher than those of neat nc‐TiO2 (3.5 %) and organized mesoporous TiO2 interfacial/nc‐TiO2 layer (5.4 %) photoanodes. The improved efficiency is attributed to the antireflective property, cascadal energy band gap, good interconnectivity, and high electrical conductivity of the om‐SnO2 IF layer, which results in enhanced light harvesting, increased electron transport, reduced charge recombination, and decreased interfacial/internal resistance.
Electrochemical Performance of Hierarchical Porous Carbon Materials Obtained from the Infiltration of Lignin into Zeolite Templates
Authors: Ruiz‐Rosas R. , Valero‐Romero M. J. , Salinas‐Torres D. , Rodríguez‐Mirasol J. , Cordero T. , Morallón E. , Cazorla‐Amorós D. 
Published: March 2014

AbstractHierarchical porous carbon materials prepared by the direct carbonization of lignin/zeolite mixtures and the subsequent basic etching of the inorganic template have been electrochemically characterized in acidic media. These lignin‐based templated carbons have interesting surface chemistry features, such as a variety of surface oxygen groups and also pyridone and pyridinic groups, which results in a high capacitance enhancement compared to petroleum‐pitch‐based carbons obtained by the same procedure. Furthermore, they are easily electro‐oxidized in a sulfuric acid electrolyte under positive polarization to produce a large amount of surface oxygen groups that boosts the pseudocapacitance. The lignin‐based templated carbons showed a specific capacitance as high as 250 F g−1 at 50 mA g−1, with a capacitance retention of 50 % and volumetric capacitance of 75 F cm−3 at current densities higher than 20 A g−1 thanks to their suitable porous texture. These results indicate the potential use of inexpensive biomass byproducts, such as lignin, as carbon precursors in the production of hierarchical carbon materials for electrodes in electrochemical capacitors.
Electrophilicities of 1,2‐Disubstituted Ethylenes
Authors: Allgäuer Dominik S. , Mayr Herbert 
Published: March 2014

AbstractThe kinetics of the reactions of maleic anhydride, N‐methylmaleimide, fumaronitrile, diethyl fumarate, and diethyl maleate with pyridinium and sulfonium ylides were studied in DMSO at 20 °C. All of the reactions were found to follow a second‐order rate law, and can be described by the linear free energy relationship log k2 (20 °C) = sN(N + E), where N and sN are solvent‐dependent nucleophile‐specific parameters, and E is an electrophile‐specific parameter. The electrophilicity parameters E of the investigated acceptor‐substituted alkenes were derived from the linear correlations of (log k2)/sN vs. N, and range from –19.8 to –11.1.
Diagnostics Using Multiplexed Electrochemical Readout Devices
Authors: Díaz‐González María , Muñoz‐Berbel Xavier , Jiménez‐Jorquera Cecilia , Baldi Antoni , Fernández‐Sánchez César 
Published: March 2014

AbstractMolecular diagnostics of human diseases requires the development of analytical tools with the capacity of simultaneously detecting several biomarkers of interest, mainly proteins and nucleic acids. Until now, most multiplexed analyses have been performed in a microarray format and using optical detection, these showing some limitations in terms of cost, portability and integration into point‐of‐care medical devices. In this context, electrochemical detection can offer an alternative to optical systems due to their high sensitivity, low‐cost, easy miniaturization and integration in compact analytical devices. This article reviews most relevant electroanalytical systems developed so far for multiplexed analysis of DNA and proteins.
Stimuli‐Responsive Biointerface Based on Polymer Brushes for Glucose Detection
Authors: Crulhas Bruno P. , Sempionatto Juliane R. , Cabral Murilo F. , Minko Sergiy , Pedrosa Valber A. 
Published: March 2014

AbstractThe construction and characterization of a biosensor based on polymer brushes is reported. The use of polymer brushes combined with nanoparticles was applied to show its suitability as a biosensor platform – with glucose oxidase as an enzyme probe. The biosensor demonstrated a pH‐sensitive on‐off property, and it was further used to control or modulate the electrochemical responses. In terms of the kinetic behavior, we were able to show the changing in the kinetic parameters of glucose oxidase operating in “on” and “off” state of the polymer brushes. The performance of the bioelectrode was investigated by chronoamperometry, impedance electrochemistry and cyclic voltammetric techniques. At optimized experimental conditions the dynamic concentration range was 2.0 to 16.0 mmol L−1 with a detection limit of 5.6×10–6 mol L−1. The repeatability of current responses for injections of 5.0 mmol L−1 glucose was evaluated to be 5.3 % (n=10). The resulting biosensor seemed to provide the enzymes with a biocompatible nanoenvironment as it sustained the enhanced enzyme activity for an extended time and promoted possible good electron transfer through the polymer brushes to the electrode.
Prediction of partition coefficients for complex environmental contaminants: Validation of COSMOtherm, ABSOLV, and SPARC
Authors: Stenzel Angelika , Goss Kai-Uwe , Endo Satoshi 
Published: March 2014

Abstract

Prediction of partition coefficients is essential for screening of environmentally relevant compounds. Prediction methods using only the molecular structure as input are especially useful for this purpose. In the present study, the authors validated 3 prediction method—COSMOtherm, ABSOLV, and SPARC—which are based on more mechanistic approaches than most other quantitative structure–activity relationships. Validation was based on a consistent experimental data set of up to 270 compounds, mostly pesticides and flame retardants. The validation systems included 3 gas chromatographic (GC) columns and 4 liquid/liquid systems that represent all relevant types of intermolecular interactions. Results revealed that the overall prediction accuracy of COSMOtherm and ABSOLV is comparable, whereas SPARC performance is substantially lower than the other methods. For instance, the root mean squared error for the 4 liquid/liquid partition coefficients was 0.65 log units to 0.93 log units for COSMOtherm, 0.64 log units to 0.95 log units for ABSOLV, and 1.43 to 2.85 log units for SPARC. In addition, version and parameterization influences of COSMOtherm on the prediction accuracy were determined. Environ Toxicol Chem 2014;33:1537–1543. © 2014 SETAC
An inexpensive, temporally integrated system for monitoring occurrence and biological effects of aquatic contaminants in the field
Authors: Kahl Michael D. , Villeneuve Daniel L. , Stevens Kyle , Schroeder Anthony , Makynen Elizabeth A. , LaLone Carlie A. , Jensen Kathleen M. , Hughes Meagan , Holmen Bruce A. , Eid Evan , Durhan Elizabeth J. , Cavallin Jenna E. , Berninger Jason , Ankley Gerald T. 
Published: March 2014

Abstract

Assessment of potential risks of complex contaminant mixtures in the environment requires integrated chemical and biological approaches. In support of the US Great Lakes Restoration Initiative, the US Environmental Protection Agency lab in Duluth, MN, is developing these types of methods for assessing possible risks of aquatic contaminants in near-shore Great Lakes (USA) sites. One component involves an exposure system for caged fathead minnow (Pimephales promelas) adults suitable for the wide range of habitat and deployment situations encountered in and around the Great Lakes. To complement the fish exposure system, the authors developed an automated device for collection of composite water samples that could be simultaneously deployed with the cages and reflect a temporally integrated exposure of the animals. The present study describes methodological details of the design, construction, and deployment of a flexible yet comparatively inexpensive (&lt;600 USD) caged-fish/autosampler system. The utility and performance of the system were demonstrated with data collected from deployments at several Great Lakes sites. For example, over 3 field seasons, only 2 of 130 deployed cages were lost, and approximately 99% of successfully deployed adult fish were recovered after exposures of 4 d or longer. A number of molecular, biochemical, and apical endpoints were successfully measured in recovered animals, changes in which reflected known characteristics of the study sites (e.g., upregulation of hepatic genes involved in xenobiotic metabolism in fish held in the vicinity of wastewater treatment plants). The automated composite samplers proved robust with regard to successful water collection (&gt;95% of deployed units in the latest field season), and low within- and among-unit variations were found relative to programmed collection volumes. Overall, the test system has excellent potential for integrated chemical–biological monitoring of contaminants in a variety of field settings. Environ Toxicol Chem 2014;33:1584–1595. © 2014 SETAC
Stabilized finite element formulations for liquid membranes and their application to droplet contact
Authors: Sauer Roger A. 
Published: March 2014

SUMMARYA liquid membrane formulation is presented that is suitable to analyze liquid films and their contact behavior. The governing strong form and weak form equations are presented in the general framework of the curvilinear coordinate system that is used for the surface description of the membrane. Particular emphasis is placed on the stabilization of the in‐plane equilibrium equations, which is essential for the quasi‐static description of liquid membranes. Two new stabilization schemes are proposed that affect only the in‐plane membrane behavior while leaving the out‐of‐plane membrane behavior unaffected. Further emphasis is placed on the description of line contact needed to impose nontrivial contact angles. The proposed formulation is discretized within the finite element method considering both standard Lagrange‐based and isogeometric NURBS‐based finite elements. Computational contact algorithms are formulated both for surface and line contact. The complete linearization of the discretize formulation is given. A large range of numerical examples is presented to illustrate the different physical aspects that are captured by the proposed formulation. The examples are further used to analyze the performance of the new stabilization schemes. Copyright © 2014 John Wiley & Sons, Ltd.
MATERNAL SENSITIVITY AND LATENCY TO POSITIVE EMOTION FOLLOWING CHALLENGE: PATHWAYS THROUGH EFFORTFUL CONTROL
Authors: Conway Anne , Mcdonough Susan C. , Mackenzie Michael , Miller Alison , Dayton Carolyn , Rosenblum Katherine , Muzik Maria , Sameroff Arnold 
Published: March 2014

ABSTRACTThe ability to self‐generate positive emotions is an important component of emotion regulation. In this study, we focus on children's latency to express positive emotions following challenging situations and assess whether this ability operates through early maternal sensitivity and children's effortful control. Longitudinal relations between maternal sensitivity, infant negative affect, effortful control, and latency to positive emotion following challenge were examined in 156 children who were 33 months of age. Structural equation models supported the hypothesis that maternal sensitivity during infancy predicted better effortful control and, in turn, shorter latencies to positive emotions following challenge at 33 months. Directions for future research are discussed.
Evaluation of benzothiophene carboxamides as analgesics and anti‐inflammatory agents
Authors: Pathak Chandramani , Ranjan Singh Rajiv , Yadav Saurabh , Kapoor Neha , Raina Varshiesh , Gupta Sarika , Surolia Avadhesha 
Published: March 2014

AbstractNonsteroid anti‐inflammatory drugs (NSAIDs) represent standard therapy for the alleviation of pain and inflammation. At present various classes of compounds have been reported as selective inhibitors of cyclooxygenase‐2 (COX‐2). However, they are associated with adverse side effects. To address these issues, we report here a new class of compounds that exhibit potent analgesic and anti‐inflammatory response. Substituted bromo‐benzothiophene carboxamides (4–11) were examined for their analgesic and anti‐inflammatory properties. Our findings demonstrate that newly synthesized bromo‐benzothiophene carboxamide derivatives 4, 6, and 8 attenuate nociception and inflammation at lower concentration than classical NSAIDs, such as ibuprofen. These compounds act by selectively inhibiting COX‐2 and by disrupting the prostaglandin‐E2‐dependent positive feedback of COX‐2 regulation, which was further substantiated by reduction in the levels of cytokines, chemokines, neutrophil accumulation, synthesis of prostaglandin‐E2, expression of COX‐2, and neutrophil activation at lower concentration than the classic NSAID ibuprofen. Toxicological study reveals that these compounds are well tolerated and metabolized to avoid any toxicity. Thus, these molecules represent a new class of analgesic and anti‐inflammatory agents. © 2014 IUBMB Life, 66(3):201–211, 2014
Improvement of GC‐MS Analysis of Shahrbabak Ziziphora tenuior Essential Oil by Using Multivariate Curve Resolution Approaches
Authors: Pakniyat Ehsan , Mousavi Mehdi 
Published: March 2014

AbstractEssential oil of aerial parts of Ziziphora tenuior growing in Shahrbabak in central Iran are isolated by hydrodistillation. Due to complexity of essential oils, there are fundamental problems such as co‐elution in their direct gas chromatography‐mass spectrometry analysis. These problems can result in low similarity matches in MS library search, so that true identification and determination of individual components may fail. In the present work, each component was identified and determined using GC‐MS coupled with multivariate curve resolution (MCR) techniques. In this way, more information along with higher accuracy and precision can be extracted from pure experimental GC‐MS data. The number of identified components found increased from 37 in direct similarity search to 80 in GC‐MS/MCR method. To identify each individual component, similarity search and Kovat's retention index comparison were implemented. The results found showed that pulegone (38.3%), 3′,5′‐dihydroxyacetophenone (22.83%), isomenthone (7.06%), 2‐methyl‐5‐(1‐methylethyl)‐phenol (3.41%), limonene (2.59%) and 2‐acetyl‐4,4‐dimethyl‐cyclopent‐2‐enone (2.49%) were the most abundant components. The reported compounds accounted for 94.39% of total content of the essential oil. A characteristic feature of the Iranian Ziziphora tenuior is the absence of piperitenone in its constituents compared with the oil of other Ziziphora species from Turkey.
Solvation Chemistry of DL‐Nor‐Valine in Aqueous Mixture of Dipolar Aprotic N,N‐Dimethyl Formamide
Authors: Mahali K. , Roy S. , Dolui B. K. 
Published: March 2014

AbstractIn this article, we reported the solubilities of the amino acid DL‐nor‐valine (VAL) at five equidistant temeratures i.e. from 15 to 35 °C in aqueous mixtures of N,N‐dimethyl formamide (DMF). The Standard free energies (ΔG (i)) and entropies (ΔS (i)) of transfer of VAL from water to aqueous mixture of cationophilic dipolar aprotic DMF have been evaluated at 25 °C. The transfer of Gibbs energies (ΔG (i)) and entropies (TΔS (i)) due to the chemical effects have been obtained after elimination of cavity effect, estimated by the scaled particle theory and dipole‐dipole interaction effects, computed by the used of Keesom‐orientation expression. The chemical contribution of transfer energetics of DL‐nor‐valine (VAL) are mainly guided by the composite effects of increased dispersion interaction, basicity effect and decreased acidity, hydrogen bonding effects, hydrophilic hydration and hydrophobic hydration of aqueous DMF mixtures as compared to that of reference solvent, water.
Nano‐composite Based on Platinum Particles and Modified Polyaniline for Methanol, Formic Acid, and Ethanol Oxidation
Authors: Kuo Chung‐Wen , Tsai Cheng‐Jang , Chen Wan‐Ping , Chen Pin‐Rong , Wu Tzi‐Yi , Tseng Ching‐Guey 
Published: March 2014

AbstractPolyaniline (PANI) is doped with poly(styrenesulfonic acid) (PSS) via a doping‐dedoping‐redoping process. Fourier transform infrared (FT‐IR) spectroscopy results confirm that PANI is doped with PSS. X‐ray photoelectron spectroscopy (XPS) results indicate that the strong interaction between Pt particles and sulfonic acid groups of PANI‐PSS. Scanning electron microscopy (SEM) images reveal that PANI‐PSS is composed of highly porous nanowires. Platinum (Pt) can be deposited onto PANI‐PSS film using the potentiostatic mode to obtain PANI‐PSS‐Pt composite electrode. Transmission electron microscopy (TEM) image result indicates that Pt particles are dispersed uniformly into the electrode. The effects of concentration on electrocatalytic oxidation of ethanol, formic acid, and methanol are investigated. Cyclic voltammetry results and chronoamperometric response measurements show that the activity and stability toward methanol oxidation of the PANI‐PSS‐Pt electrode are better than those of the PANI‐PSS‐Pt electrodes toward ethanol and formic acid oxidation.
Photocatalytic degradation kinetics and mechanisms of antibacterial triclosan in aqueous TiO2 suspensions under simulated solar irradiation
Authors: Stamatis Nikolaos , Antonopoulou Maria , Hela Dimitra , Konstantinou Ioannis 
Published: March 2014

AbstractBACKGROUNDThe present study focuses on the photocatalytic transformation and mineralization of triclosan (TCS) using TiO2 catalyst. The main objectives were: (a) to investigate the effect of TiO2, TCS concentration and irradiation intensity on the photocatalytic efficiency and to model the degradation and mineralization percentage of TCS using response surface methodology (RSM) based on central composite design (CCD); (b) to identify transformation products (TPs) and degradation mechanisms, (c) to assess the toxicity of the TPs.RESULTSThe results from the RSM analysis indicated that all operating parameters studied have significant effects on TCS degradation and mineralization. A quadratic response surface model was found to fit the experimental data and was used to find the optimum experimental conditions. Scavenging experiments indicated that HO• radicals were principally responsible for TCS degradation. The transformation of TCS involved reactions of mono‐ and di‐ hydroxylation, dechlorination, and cleavage of the ether bond. Total detoxification of the treated solution was obtained after 30 min, as revealed by Microtox bioassay.CONCLUSIONTCS can be effectively degraded and mineralized using TiO2 under simulated solar light avoiding the formation of highly toxic TPs. RSM modeling provided a statistically accurate prediction of the optimum degradation and mineralization of TCS. © 2014 Society of Chemical Industry
Recovery of streptomycin sulfate from the wastewater using foam fractionation coupled with adsorption separation for reusing sodium dodecyl sulfate
Authors: Kou Qian‐yun , Li Juan , Zhao Bin , Wu Zhao‐liang 
Published: March 2014

AbstractBACKGROUNDSurfactants are always used as collectors to form complexes with the hazardous materials of wastewaters in foam fractionation. An important topic is how to reuse the surfactants in the process of recovering the hazardous materials. In this work, a novel technology of foam fractionation coupled with adsorption separation was developed for separating streptomycin sulfate (SS) from its simulated wastewater and reusing the collector sodium dodecyl sulfate (SDS).RESULTSD152 resin had a high SS adsorption capacity and a low SDS adsorption capacity using adsorption separation. A high SS desorption percentage of 96.0% was obtained while SDS was not desorbed. The desorbed resin still had the same high SS adsorption capacity as a fresh one and SDS was not adsorbed. From the coupling technology, the SS recovery percentage reached as high as 94.1% which was better than foam fractionation or adsorption separation, respectively and 93.7% of SDS was reused.CONCLUSIONIt was effective for the coupling technology not only to separate SS from the wastewaters, but also to reuse SDS in foam fractionation. The coupling technology gave a novel and effective method for treating wastewaters. © 2014 Society of Chemical Industry
Multiplicative by nature: Logarithmic transformation in allometry
Authors: Packard Gary C. 
Published: March 2014

ABSTRACTThe traditional allometric method, which is at the heart of research paradigms used by comparative biologists around the world, entails fitting a straight line to logarithmic transformations of the original bivariate data and then back‐transforming the resulting equation to form a two‐parameter power function in the arithmetic scale. The method has the dual advantages of enabling investigators to fit statistical models that describe multiplicative growth while simultaneously addressing the multiplicative nature of residual variation in response variables (heteroscedasticity). However, important assumptions of the traditional method seldom are assessed in contemporary practice. When the assumptions are not met, mean functions may fail to capture the dominant pattern in the original data and incorrect form for error may be imposed upon the fitted model. A worked example from metabolic allometry in doves and pigeons illustrates both the power of newer statistical procedures and limitations of the traditional allometric method. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 202–207, 2014. © 2014 Wiley Periodicals, Inc.