bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supramolecular interaction of 18‐crown‐6 ether with mesalazine and spectrofluorimetric determination of mesalazine in pharmaceutical formulations
Authors: Elbashir Abdalla A. , Abdalla Fatima Altayib Alasha , Aboul‐Enein Hassan Y. 
Published: March 2015

AbstractThe supramolecular interaction of protonated mesalazine (MSZ) and 18‐crown‐6 ether (18C6) has been examined by Ultraviolet–visible, FT‐IR and fluorescence spectroscopy. The formation of the inclusion complex has been confirmed based on the changes of the spectral properties. The MSZ–18C6 host–guest complex formed in (1:1) stoichiometry and the inclusion constant (K = 1.411 × 102 L mol–1) was ascertained by the typical double reciprocal plots. Furthermore, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) of (MSZ‐18C6) were obtained. Based on the remarkable enhancement of the fluorescence intensity of MSZ produced through complex formation, a simple, accurate, rapid and highly sensitive spectrofluorometric method for the determination of MSZ in aqueous solution in the presence of 18C6 was developed. The measurement of relative fluorescence intensity was carried with excitation at 298 nm, emission 410 nm. All variables affecting the reactions were studied and optimized. Beer's law was obeyed in the concentration range of 0.1–0.9 µg/mL. The absorbance was found to increase linearly with increasing concentration of MSZ. The molar absorptivity, Sandell sensitivity, limit of detection (LOD) and limit of quantification (LOQ) were calculated. The validity of the described method was assessed, and the method was successfully applied to the determination of MSZ in its pharmaceutical formulation. In addition, a solid inclusion complex was synthesized by the coprecipitation method. Copyright © 2015 John Wiley & Sons, Ltd.
Development and validation of a high performance liquid chromatography method for determination of 6‐benzyl‐1‐benzyloxymethyl‐5‐iodouracil (W‐1), a novel non‐nucleoside reverse transcriptase inhibitor and its application to a pharmacokinetic study in rats
Authors: Lu Ying‐Yuan , Wang Xin , Wang Xiao‐Wei , Liu Jun‐Yi , Li Pu , Ren Hong , Lou Ya‐Qing , Lu Chuang , Zhang Guo‐Liang 
Published: March 2015

AbstractA sensitive and selective high‐performance liquid chromatographic (HPLC) method for determination of 6‐benzyl‐1‐benzyloxymethyl‐5‐iodouracil (W‐1), a novel non‐nucleoside reverse transcriptase inhibitor in rat plasma, was developed and validated. Chromatographic separation of W‐1 and megestrol acetate (internal standard) was achieved on a reversed‐phase C18 column at 25°C. The mobile phase was consisted of acetonitrile–water (60:40, v/v) and pumped at a flow rate of 1.0 mL/min. The ultraviolet (UV) detector was set at the absorption wavelength of 284 nm. The calibration curve for W‐1 was linear over the concentration range of 0.01–8 µg/mL and the lower limit of quantification was 10 ng/mL. The intra‐ and inter‐day precision and accuracy were <8.9 and 5.3%, respectively. The extraction recoveries ranged from 97.9 to 101.6%. The validated HPLC method was successfully applied to a pharmacokinetic study of W‐1 in rats. Copyright © 2015 John Wiley & Sons, Ltd.
δ‐Catenin interacts with LEF‐1 and negatively regulates its transcriptional activity
Authors: He Yongfeng , Ki Hyunkyoung , Kim Hangun , Kim Kwonseop 
Published: March 2015

Abstractδ‐Catenin and β‐catenin belong to different subfamilies of armadillo proteins but share some common binding partners, such as E‐cadherin. This is the first study that demonstrated a novel common binding partner for δ‐catenin and β‐catenin, lymphoid enhancer factor‐1 (LEF‐1). We found that the N‐terminus of δ‐catenin (amino acids 85–325) bound to the middle region of LEF‐1 unlike β‐catenin. Overexpressed δ‐catenin entered the nucleus and inhibited LEF‐1‐mediated transcriptional activity in Bosc23 and DLD‐1 cell lines. The current study provided novel insights that will provide a better understanding of the effects of δ‐catenin on Wnt/LEF‐1‐mediated transcriptional activity.
Importance of Myc‐related microRNAs in induced pluripotency
Authors: Çağlayan E. Sacide , Güran Şefik 
Published: March 2015

AbstractPluripotent stem cells (PSCs) have the capacity to differentiate into any cell type of the body. Therefore, induced pluripotent stem cells (iPSCs) are seen as a promising solution for patient‐specific cell therapies. However, the safety is major issue for in vitro methods that are used in induction of pluripotency and also in differentiation of PSCs toward specific cell types. In pioneer studies of iPSC generation, the role of c‐Myc has been highlighted as a possible master regulator of pluripotency, but direct c‐Myc overexpression is known to prompt drawbacks, especially in human cells. In recent studies, the role of non‐protein coding RNA molecules such as microRNAs (miRNAs) has been shown in enhanced reprogramming efficiency. In addition, new reprogramming methods have been ultimately improved by adding miRNAs, in the absence of previous factors. Cross interaction between miRNAs and c‐Myc has been also found in differentiation of iPSCs, as well as in reprogramming and self‐renewing the pluripotent state. Thence, miRNAs are promising solution for efficiency and safety of iPSC derivation and differentiation methods. The purpose of the present review is to evaluate interaction mechanisms of miRNAs with c‐Myc and in iPSC technology.
Advanced Oxygen Sensing for Accurate Gas Diffusivity Measurements in Fuel Cells
Authors: Lv Weiqiang , Feng Na , Huo Weirong , Niu Yinghua , Wang Siyuan , Wang Xiaoning , Liang Yachun , Zhu Gaolong , He Weidong 
Published: March 2015

AbstractImpeded gas diffusion causes serious concentration polarization (CP) in fuel cells. The facile and accurate measurement of gas diffusivities in various electrodes facilitates the pre‐evaluation of two key parameters in fuel cells, that is, the limiting current density (LCD) and CP. However, previously reported electrochemical devices for this purpose only employ a single oxygen voltage sensor, which induces inevitable voltage errors, owing to the existing oxygen gradient across the measurement tube. In this report, the correlation of such voltage errors with the errors of diffusivity measurement as well as the errors in pre‐evaluating LCD and CP is analyzed quantitatively. A dual oxygen‐sensing device is then proposed for the first time to eliminate the voltage errors, allowing for accurate diffusivity measurements and reliable pre‐evaluation of LCD and CP in fuel cells with both bulk and thin nanostructured electrodes operated at different temperatures.
Covariances Simultaneous Component Analysis: a new method within a framework for modeling covariances
Authors: Smilde Age K. , Timmerman Marieke E. , Saccenti Edoardo , Jansen Jeroen J. , Hoefsloot Huub C. J. 
Published: March 2015

In modern omics research, it is more rule than exception that multiple data sets are collected in a study pertaining to the same biological organism. In such cases, it is worthwhile to analyze all data tables simultaneously to arrive at global information of the biological system. This is the area of data fusion or multi‐set analysis, which is a lively research topic in chemometrics, bioinformatics, and biostatistics. Most methods of analyzing such complex data focus on group means, treatment effects, or time courses. There is also information present in the covariances among variables within a group, because this relates directly to individual differences, heterogeneity of responses, and changes of regulation in the biological system.We present a framework for analyzing covariance matrices and a new method that fits nicely in this framework. This new method is based on combining covariance prototypes using simultaneous components and is, therefore, coined Covariances Simultaneous Component Analysis (COVSCA). We present the framework and our new method in mathematical terms, thereby explaining the (dis)similarities of the methods.Systems biology models based on differential equations illustrate the type of variation generated in real‐life biological systems and how this type of variation can be modeled within the framework and with COVSCA. The method is subsequently applied to two real‐life data sets from human and plant metabolomics studies showing biologically meaningful results. Copyright © 2015 John Wiley & Sons, Ltd.
The Structural Influence of Graphene Oxide on Its Fragmentation during Laser Desorption/Ionization Mass Spectrometry for Efficient Small‐Molecule Analysis
Authors: Kim Young‐Kwan , Min Dal‐Hee 
Published: March 2015

AbstractThe structural influence of graphene oxide (GO) on laser desorption/ionization mass spectrometry (LDI‐MS) analysis of small molecules was systematically investigated by using size‐fractionated GO. For fractionation of GO, pH‐assisted centrifugation, sequential vacuum filtration, and sonochemical cutting processes were employed and the size‐fractionated GO was thoroughly characterized to understand their size‐dependent optochemical properties. Then, the fractionated GO was applied to the analysis of various small molecules by LDI‐MS to investigate the relationship between their optochemical properties and LDI‐MS performance. We found that large GO sheets (>0.5 μm) were more prone to fragmentation under laser irradiation during LDI‐MS analysis than small GO sheets (<0.5 μm). In this regard, the LDI‐MS analysis efficiency of various small molecules was significantly improved by using nanosized GO (NGO) as a matrix without background interference. In particular, NGO was successfully applied to the sensitive detection of hydrophobic pollutant molecules without requiring any surface‐functionalization, enrichment, and separation process. Therefore, the present study could provide important basic information and be a practical tool for the development of simple and efficient LDI‐MS platforms by using GO derivatives.
The Acidity of the HBr/AlBr3 System: Stabilization of Crystalline Protonated Arenes and Their Acidity in Bromoaluminate Ionic Liquids
Authors: Scholz Franziska , Himmel Daniel , Eisele Lea , Unkrig Wiebke , Martens Arthur , Schlüter Peter , Krossing Ingo 
Published: March 2015

AbstractBulk protonated mesitylene, toluene, and benzene bromoaluminate salts were stabilized and characterized in the superacidic system HBr/n AlBr3 with NMR spectroscopy and X‐ray analysis of [HC6H3(CH3)3]+[AlBr4]− (1), [HC6H5(CH3)]+[AlBr4]− (2), and [C6H7]+[Al2Br7]−⋅C6H6 (3). Protonation attempts in bromoaluminate ILs led to a complete protonation of mesitylene, and a protonation degree of up to 15 % for toluene in the IL BMP+[Al2Br7]−. Benzene could only be protonated in the more acidic IL BMP+[Al3Br10]−, with a degree of 25 %. Protonation attempts on aromatics provide evidence that the bromoaluminate ILs tolerate superacidic environments. On the basis of the absolute Brønsted acidity scale, quantum chemical calculations confirmed the superacidic properties, and rank the acidities in ILs down to a pHabs value of 164 with an error of less than one pH unit compared with experimental findings. The neat AlBr3/HBr system even may reach acidities down to pHabs 163.
Valence Bond and Enzyme Catalysis: A Time To Break Down and a Time To Build Up
Authors: Sharir‐Ivry Avital , Varatharaj Rajapandian , Shurki Avital 
Published: March 2015

AbstractUnderstanding enzyme catalysis and developing ability to control of it are two great challenges in biochemistry. A few successful examples of computational‐based enzyme design have proved the fantastic potential of computational approaches in this field, however, relatively modest rate enhancements have been reported and the further development of complementary methods is still required. Herein we propose a conceptually simple scheme to identify the specific role that each residue plays in catalysis. The scheme is based on a breakdown of the total catalytic effect into contributions of individual protein residues, which are further decomposed into chemically interpretable components by using valence bond theory. The scheme is shown to shed light on the origin of catalysis in wild‐type haloalkane dehalogenase (wt‐DhlA) and its mutants. Furthermore, the understanding gained through our scheme is shown to have great potential in facilitating the selection of non‐optimal sites for catalysis and suggesting effective mutations to enhance the enzymatic rate.
Development of Modifiable Bidentate Amino Oxazoline Directing Group for Pd‐Catalyzed Arylation of Secondary CH Bonds
Authors: Chen Kang , Li Zhao‐Wei , Shen Peng‐Xiang , Zhao Hong‐Wei , Shi Zhang‐Jie 
Published: March 2015

AbstractA novel bidentate α‐amino oxazolinyl directing group has been developed. Different from previous directing groups, this newly designed directing group was easily prepared from amino acids and modified in structure. This auxiliary preferentially effects functionalization at secondary C(sp3)H bonds, rather than at aryl C(sp2)H bonds. The diastereoselectivity of direct arylation between geminal secondary C(sp3)H bonds in linear molecules has also been realized for the first time with a chiral directing group by remote chirality relay. Two diastereoisomers are produced with the same chiral source by changing the substituents of substrates and aryl halides.
Simulation of One‐Stage Dimethyl Ether Synthesis over a Core‐Shell Catalyst
Authors: Ding Wenjin , Klumpp Michael , Lee Seungcheol , Reuß Stephanie , Al‐Thabaiti Shaeel A. , Pfeifer Peter , Schwieger Wilhelm , Dittmeyer Roland 
Published: March 2015

AbstractA spherical microsized core‐shell catalyst (CuO/ZnO/Al2O3@H‐ZSM‐5) was synthesized for direct dimethyl ether synthesis from syngas in a micro packed bed reactor. To assist in the preparation and optimization of the core‐shell catalyst, a 1D heterogeneous model was developed to simulate diffusion and reactions within the catalyst particles. Using the data obtained from the tubular reactor, kinetic parameters for the catalyst were determined first. Furthermore, simulation showed that thickness and activity of shell have significant effect on the catalytic performance of the core‐shell catalyst.
Polymorphism in New Thienothiophene–Thiazolothiazole Organic Semiconductors
Authors: Schneider Julia A. , Black Hayden , Lin Hua‐Ping , Perepichka Dmitrii F. 
Published: March 2015

AbstractCharge transport in organic semiconductors is heavily influenced by their solid‐state packing. To separate intermolecular packing effects from molecular electronic effects, we have synthesized two polymorphs of crystalline thienothiophene–thiazolothiazole trimers and studied them by DFT calculations, optical spectroscopy, single‐crystal X‐ray diffraction and charge‐transport measurements in field‐effect transistors. One polymorph was found to be a p‐type semiconductor with a hole mobility of 3.3×10−3 cm2 V−1 s−1, while the other was insulating. The different charge‐transport behavior and optical properties of the two polymorphs are strongly related to the topology of their π‐stacks. Subtle differences between the polymorphs, including S⋅⋅⋅S close contacts and bond‐length alternation are also discussed for their possible effects on charge transport.
Oxidation of Organosilanes with Nanoporous Copper as a Sustainable Non‐Noble‐Metal Catalyst
Authors: Li Zhiwen , Xu Xiaohong , Zhang Xiaomei 
Published: March 2015

AbstractAlthough many noble‐metal catalysts have been used for the oxidation of organosilanes, there has been less success with non‐noble‐metal catalysts. Here, unsupported nanoporous copper (np‐Cu) is used to catalyze the oxidation of organosilanes under mild conditions. It is the first time that this reaction has been achieved with a heterogeneous copper catalyst with high activity and selectivity. Both water and alcohols are used as oxidants and the corresponding organosilanols and organosilyl ethers are obtained in high yield. The possible mechanism was obtained by kinetic studies. The catalyst could be reused at least five times without evident loss of activity. As a novel green catalyst np‐Cu should play a unique role in organic synthesis.
Cross‐Metathesis of Biosourced Fatty Acid Derivatives: A Step Further Toward Improved Reactivity
Authors: Vignon Paul , Vancompernolle Tom , Couturier Jean‐Luc , Dubois Jean‐Luc , Mortreux André , Gauvin Régis M. 
Published: March 2015

AbstractInvited for the cover of this issue is the group of Régis Gauvin at the Unit for Catalysis and Solid State Chemistry, Université Lille Nord de France. The image shows how cross‐metathesis of bio‐sourced fatty esters can be efficiently performed using internal functionalized olefins. The Communication itself is available at 10.1002/cssc.201403170.
Push applications and dynamic content generation over content‐centric networking
Authors: Virgilio Matteo , Marchetto Guido , Sisto Riccardo 
Published: March 2015

SummaryContent‐Centric Networking (CCN) represents an established candidate for the future Internet, proposing a routing architecture designed to elevate content to first class entity. Starting from the fact that the network usage has dramatically evolved towards content retrieval, CCN relies on an on‐demand pull based mechanism to transfer data from the different sources to the heterogeneous consumers. This paradigm enhances the network in a number of ways, ranging from the newly introduced in‐network caching capabilities to the benefits provided by the symmetric data routing adopted by CCN. In this renewed network scenario, we place our attention to those applications that do not perfectly fit the pull paradigm, stating that they need to be supported as well and proposing an effective way to achieve scalability on large scale push applications. We provide the following contributions: (i) we identify the functions that a data‐centric architecture should support; (ii) propose and compare our solution with the state of the art framework designed for the specific problem of pushing data to content requesters; and (iii) evaluate their performance in terms of traffic generated and scalability achieved by simulating a real Internet Service Provider (ISP) topology and the realistic workload of a generic social network application. Copyright © 2015 John Wiley & Sons, Ltd.
The influence of adolescent eating disorders or disordered eating behaviors on socioeconomic achievement in early adulthood
Authors: Tabler Jennifer , Utz Rebecca L. 
Published: March 2015

ABSTRACTObjectiveMuch research documents the etiology and health consequences of adolescent eating disorders (ED), but very little is known about the long‐term effects of EDs on the transition to adulthood. This study explores gender differences in the influence of EDs or disordered eating behaviors (DEB) on measures of socioeconomic independence in early adulthood.MethodUsing the National Longitudinal Study of Adolescent Health (Add Health), this study compares individuals who self‐identified as have been diagnosed with an ED or engaged in DEBs in late adolescence to those without ED or DEB on three measures of socioeconomic independence during early adulthood, including educational attainment, income, and likelihood of owning a home. This study uses multiple regression techniques and attempts to account for early‐life conditions and health outcomes associated with EDs and DEBs.ResultsFor females, ED or DEB in late adolescence had a statistically significant, negative association with educational attainment (coefficient = −0.20, p = .05), personal income (coefficient = −0.12, p < .05) and odds of owning a home (odds ratio = 0.73, p < .02) in early adulthood. For males, ED or DEB was not associated with socioeconomic attainment.DiscussionOur findings suggest that EDs and DEBs are negatively associated with socioeconomic achievement during early adulthood for females, but not for males. EDs or DEBs during adolescence may set individuals on a different trajectory whereby they do not have the same life chances or opportunities for success in adulthood. These results confirm the public health message that EDs or DEBs have lasting negative consequences for women. © 2015 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:622–632)
Household Energy Use and Carbon Emissions in China: A decomposition analysis
Authors: Zhu Qin , Wei Taoyuan 
Published: March 2015

AbstractAlthough its per‐capita carbon emissions are still relatively low, China's aggregated carbon emissions have grown nearly four‐fold in the last three decades, and now it is the biggest CO2 emitter in the world. There are many reasons for this emissions growth, and much emphasis has been placed on industrial development, but previous research has estimated that 40% of the growth in Chinese CO2 emissions over the 15 years to 2007 can be attributed to household energy consumption. Here we conduct a decomposition analysis to show that in the period from 1978 to 2008 nearly 60% of the growth in Chinese household emissions can be attributed to the increasing number of households and 40% to increasing emissions per household. We also show that over this period emissions growth in urban households has been six times that of rural households. These results have important implications for policy‐makers seeking to promote reductions in China's CO2 emissions, relating for example to family planning and urbanization. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment
Electrochemical Sensors Using Two‐Dimensional Layered Nanomaterials
Authors: Su Shao , Chao Jie , Pan Dun , Wang Lianhui , Fan Chunhai 
Published: March 2015

AbstractTwo‐dimensional (2D) layered nanomaterials, e.g. graphene and molybdenum disulfide (MoS2), have rapidly emerged in material sciences due to their unique physical, chemical and mechanical properties. In the meanwhile, there is a growing interest in constructing electrochemical sensors for a wide range of chemical and biological molecules by using these 2D nanomaterials. In this review, we summarize recent advances on using graphene and MoS2 for the development of electrochemical sensors for small molecules, proteins, nucleic acids and cells detection. We also provide our perspectives in this rapidly developing field.
Preparation, Characterization and Electrochemical Application of ZnO‐CuO Nanoplates for Voltammetric Determination of Captopril and Tryptophan Using Modified Carbon Paste Electrode
Authors: Beitollahi Hadi , Ghofrani Ivari Susan , Alizadeh Reza , Hosseinzadeh Rahman 
Published: March 2015

Abstract2‐chlorobenzoyl ferrocene, was synthesized and used to construct a modified ZnO‐CuO nanoplates modified carbon paste electrode. The electrooxidation of captopril at the surface of the modified electrode was studied. Under the optimized conditions, the square wave voltammetric (SWV) peak current of captopril increased linearly with captopril concentration in the range of 5.0×10−7 to 9.0×10−4 M and detection limit of 90.0 nM was obtained for captopril. The diffusion coefficient and kinetic parameters (such as electron transfer coefficient and the heterogeneous rate constant) for captopril oxidation were also determined. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of captopril and tryptophan which makes it suitable for the detection of captopril in the presence of tryptophan in real samples.