bluuebunny/crossref_metadata_2025_split huggingface dataset:
A rapid analytical method for monitoring the enantiomeric purity of chiral molecules synthesized in ionic liquid solvents
Authors: Zhao Qichao , Twu Pamela , Anderson Jared L. 
Published: January 2012

AbstractIonic liquids (ILs) have been widely used as reaction solvents in asymmetric synthesis due to their interesting physical and chemical properties. However, monitoring reactant‐to‐product conversion and the enantiopurity of formed stereoisomers often involves a tedious extraction step before chromatographic analysis. In this study, a rapid and sensitive sampling method using headspace solid‐phase microextraction (SPME) coupled to chiral gas chromatography was developed for the “on‐line” analysis of chiral molecules in the IL solvent. Three different SPME sorbent coatings, namely polydimethylsiloxane, polyacrylate, and a polymeric ionic liquid‐based fiber, were examined in this study. The analytical performance of the developed method was evaluated in terms of reproducibility, slope of calibration curve, linear range, calibration linearity, and the determination of detection limits. The SPME method was successfully applied in the determination of enantiomeric excess from selected mixtures of chiral molecules. A preliminary study was performed using an “on‐fiber” derivatization approach revealing that the stereoisomers extracted by the SPME fiber can be efficiently derivatized using a short “on‐fiber” derivatization step. The developed SPME method eliminates the need of sequestering the reaction, separating the compounds of interest from the IL solvent, and the addition of a derivatizing reagent. Chirality, 2012. © 2012 Wiley Periodicals, Inc.
Chiral separation of vinpocetine using cyclodextrin‐modified micellar electrokinetic chromatography
Authors: Ibrahim Wan Aini Wan , Wahib Siti Munirah Abd , Hermawan Dadan , Sanagi Mohd Marsin , Aboul‐Enein Hassan Y. 
Published: January 2012

AbstractA cyclodextrin‐modified micellar electrokinetic chromatography (CD‐MEKC) technique has been developed for enantioseparation of vinpocetine using an inexpensive 2‐hydroxypropyl‐β‐CD (HP‐β‐CD) as the chiral selector (CS). The best chiral separation was achieved using 40 mM HP‐β‐CD as the CS in 50 mM phosphate buffer (pH 7.0) consisting of 40 mM sodium dodecyl sulfate (SDS) at a separation temperature and separation voltage of 25°C and 25 kV, respectively. To the author's best knowledge, this is the first CD‐MEKC study able to successfully separate the four stereoisomer of vinpocetine in separation time of 9.5 min and resolution of 1.04–3.87. Chirality, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis and Evaluation of 1‐Amino‐6‐halo‐β‐carbolines as Antimalarial and Antiprion Agents
Authors: Thompson Mark J. , Louth Jennifer C. , Little Susan M. , Jackson Matthew P. , Boursereau Yohan , Chen Beining , Coldham Iain 
Published: January 2012

AbstractMalaria is one of the world’s most devastating parasitic diseases, causing almost one million deaths each year. Growing resistance to classical antimalarial drugs, such as chloroquine, necessitates the discovery of new therapeutic agents for successful control of this global disease. Here, we report the synthesis of some 6‐halo‐β‐carbolines as analogues of the potent antimalarial natural product, manzamine A, retaining its heteroaromatic core whilst providing compounds with much improved synthetic accessibility. Two compounds displayed superior activity to chloroquine itself against a resistant Plasmodium falciparum strain, identifying them as promising leads for future development. Furthermore, in line with previous reports of similarities in antimalarial and antiprion effects of aminoaryl‐based antimalarial agents, the 1‐amino‐β‐carboline libraries were also found to possess significant bioactivity against a prion‐infected cell line.
Influence of the Number of Anchoring Groups on the Electronic and Mechanical Properties of Benzene‐, Anthracene‐ and Pentacene‐Based Molecular Devices
Authors: Martín‐Lasanta Ana , Miguel Delia , García Trinidad , López‐Villanueva Juan A. , Rodríguez‐Bolívar Salvador , Gómez‐Campos Francisco M. , Buñuel Elena , Cárdenas Diego J. , de Cienfuegos Luis Álvarez , Cuerva Juan M. 
Published: January 2012

AbstractOne of the central issues of molecular electronics (ME) is the study of the molecule–metal electrode contacts, and their implications for the conductivity, charge‐transport mechanism, and mechanical stability. In fact, stochastic on/off switching (blinking) reported in STM experiments is a major problem of single‐molecule devices, and challenges the stability and reliability of these systems. Surprisingly, the ambiguous STM results all originate from devices that bind to the metallic electrode through a one‐atom connection. In the present work, DFT is employed to study and compare the properties of a set of simple acenes that bind to metallic electrodes with an increasing number of connections, in order to determine whether the increasing numbers of anchoring groups have a direct repercussion on the stability of these systems. The conductivities of the three polycyclic aromatic hydrocarbons are calculated, as well as their transmission spectra and current profiles. The thermal and mechanical stability of these systems is studied by pulling and pushing the metal–molecule connection. The results show that molecules with more than one connection per electrode exhibit greater electrical efficiency and current stability.
Further Insight into the Photostability of the Pyrene Fluorophore in Halogenated Solvents
Authors: Aguilera‐Sigalat Jordi , Sanchez‐SanMartín Jaime , Agudelo‐Morales Carlos E. , Zaballos Elena , Galian Raquel E. , Pérez‐Prieto Julia 
Published: January 2012

AbstractPyrene fluorophores of pyrene‐functionalized CdSe quantum dots (QD@Py), as well as alkylpyrene and pyrene itself (Py), undergo fast degradation in aerated chloroform under ultraviolet‐A (UV‐A, 316<λ<400 nm) illumination. Steady‐state fluorescence studies of irradiated chloroform solutions of QD@Py show formation of new bands, red‐shifted compared to that of the pyrene moiety. Similar behaviour is observed for pyrene and the alkylpyrene system. Column chromatography of the pyrene photolysate in chloroform allowed us to isolate photoproducts arising from pyrene degradation, and to obtain information on the structure of the photoproducts responsible for the emission bands. The most predominant photoproducts were those originating from the reaction of pyrene with dichloromethyl radicals. The phototransformation of QD@Py and the alkylpyrene involves mainly detachment of the alkyl chain from the aromatic ring, induced also by dichloromethyl radicals, and oxidation of the alkyl chain at the benzylic position was detected as well. By contrast, these pyrene systems show a high photostability in aerated dichloromethane. Transient absorption measurements showed formation of both pyrene triplet and pyrene radical cation for all pyrene systems in these halogenated solvents. The yield of pyrene radical cations for Py is higher than for QD@Py and the alkylpyrene. In addition, pyrene radical cations were longer‐lived in dichloromethane than in chloroform. The reason for the pyrene photostability in dichloromethane is the different reactivity of chloromethyl and dichloromethyl radicals towards pyrene and oxygen. These studies show that the use of dichloromethane can be a suitable alternative to chloroform when the good solubility properties of these halogenated solvents are needed to dissolve pyrene when this chromophore is used as a fluorescent probe.
Reduced respiratory muscle strength and endurance in type 2 diabetes mellitus
Authors: Fuso Leonello , Pitocco Dario , Longobardi Anna , Zaccardi Francesco , Contu Chiara , Pozzuto Carmen , Basso Salvatore , Varone Francesco , Ghirlanda Giovanni , Antonelli Incalzi Raffaele 
Published: January 2012

AbstractBackgroundA restrictive lung function pattern is frequently observed in patients with diabetes mellitus (DM) and has been related to respiratory muscle dysfunction in type 1 DM or in mixed population. We aimed to verify whether such a relationship applies also to type 2 DM patients.MethodsThe respiratory muscle function was explored in 75 non‐smoking patients with type 2 DM without pulmonary or cardiac diseases and compared with that of 40 healthy non‐smoking control subjects matched by age and sex. Maximal inspiratory and expiratory pressures (MIP, MEP) and maximum voluntary ventilation (MVV), which reflect respiratory muscle strength and endurance, respectively, were measured, and a complete respiratory function assessment was recorded.ResultsPatients were in stable metabolic conditions and had, on average, normal total lung capacity and diffusing lung capacity for carbon monoxide. However, MIP and MVV were significantly reduced in comparison with those of control subjects. Both MIP/MEP and MVV significantly correlated with lung volumes and diffusing lung capacity for carbon monoxide. The multiple regression analysis identified age (beta coefficient = −0.238, p = 0.046), glycated haemoglobin (beta coefficient = −0.245, p = 0.047) and total lung capacity (beta coefficient = 0.430, p = 0.016) as independent correlates of MIP, whereas male sex (beta coefficient = 0.423, p = 0.004) and diabetic complications (beta coefficient = −0.248, p = 0.044) were independent correlates of MVV.ConclusionsIn type 2 DM, respiratory muscle strength was reduced and significantly related to lung volumes and quality of metabolic control, whereas impaired endurance of respiratory muscles prevailed in patients with microvascular complications. Copyright © 2012 John Wiley & Sons, Ltd.
Possible association of the DRD4 gene with a history of attention‐deficit/hyperactivity disorder in women with bulimia nervosa
Authors: Yilmaz Zeynep , Kaplan Allan S. , Levitan Robert D. , Zai Clement C. , Kennedy James L. 
Published: January 2012

AbstractObjective:Up to one‐third of patients with bulimia nervosa (BN) report a history of attention‐deficit/hyperactivity disorder (ADHD) symptoms, and the dopaminergic genes, especially the dopamine receptor D4 (DRD4), have been associated independently with both binge eating and ADHD.Method:The purpose of this study was to (1) compare the frequency of DRD4 exon III VNTR variants in 157 BN probands and equal number of healthy controls; (2) assess transmission of DRD4 alleles in 68 families of patients with BN; and (3) explore the possible role of DRD4 gene in childhood ADHD history in a subgroup of 81 women with BN.Results:Our results showed that the BN probands and controls did not differ in DRD4 allele frequency. We also did not find evidence for preferential transmission of any DRD4 variant to the affected offspring with BN. However, the presence of either the 2‐repeat or 7‐repeat allele was associated with a history of childhood ADHD in BN (p = .038, odds ratio = 3.2).Discussion:Our findings suggest that although DRD4 may not be associated with the diagnosis of BN, its variants are associated with a history of childhood ADHD in BN probands. This may have relevance for the understanding, prevention, and treatment of BN that evolves in the context of childhood ADHD. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Local Climate Action Plans in France: Emergence, Limitations and Conditions for Success
Authors: Yalçın Melike , Lefèvre Benoit 
Published: January 2012

ABSTRACTA growing number of local governments worldwide are addressing climate change by locally developed climate action plans (CAPs). In this paper, we analyse the first generation of voluntary and partnership‐based CAPs in France. On the basis of data collected from Grenoble Alpes Métropole and other French pioneer cities, we try to find out what the experiences of these pioneer cities teach us about the triggering factors, the scope, the limitations and the conditions for success of CAPs. Our study shows that CAPs help to raise awareness about climate and energy issues and to bring local stakeholders together to develop shared solutions suited to local specificities. However, they do not seem to launch ambitious operations conducted in a cross‐cutting manner. Their effective implementation depends on the resources available to authorities, as well as the incentives and support that they receive. Moreover, meeting the CAP targets requires the authorities' ability to promote and utilize partnerships to mobilize all local potential for energy efficiency and GHG emission reduction. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Segment Solid‐Phase Total Synthesis of the Anthelmintic Cyclooctadepsipeptides PF1022A and Emodepside
Authors: Scherkenbeck Jürgen , Lüttenberg Sebastian , Ludwig Monika , Brücher Karin , Kotthaus Andreas 
Published: January 2012

AbstractCyclodepsipeptides of the enniation, PF1022 and verticilide families represent a diverse class of highly interesting natural products with respect to their manifold biological activities. However, until now, no practicable solid‐phase syntheses of these compounds have been accomplished, probably due to the problematic combination of N‐methyl amino acids and hydroxycarboxylic acids. We report herein an efficient synthesis of the anthelmintic PF1022A and its commercial analogue emodepside on Kaiser and Wang resins. Our protocol provides the basis for the solid‐phase synthesis of cyclodepsipeptide libraries with a high probability of anthelmintic, antibacterial or insecticidal activity.
Oxidative Homologation of Aldehydes to α‐Ketoaldehydes by using Iodoform, o‐Iodoxybenzoic Acid, and Dimethyl Sulf­oxide
Authors: Zall Andrea , Bensinger Dennis , Schmidt Boris 
Published: January 2012

AbstractAn efficient three‐step synthetic route to α‐ketoaldehydes starting from aryl aldehydes is reported. The aldehydes were treated with iPrMgCl and iodoform to obtain β‐diiodoalcohols, which were then oxidized with o‐iodoxybenzoic acid at room temperature to the corresponding β‐diiodoketones. Subsequent reaction of the β‐diiodoketone to the α‐ketoaldehyde occurred under oxygen transfer from dimethyl sulfoxide. These sensitive products were in situ cyclized with o‐phenylenediamine to form the stable monosubstituted quinoxalines, which could be characterized and isolated easily.
Intrinsic religiosity reduces intergroup hostility under mortality salience
Authors: Golec de Zavala Agnieszka , Cichocka Aleksandra , Orehek Edward , Abdollahi Abdolhossein 
Published: January 2012

AbstractResults of three studies indicate that intrinsic religiosity and mortality salience interact to predict intergroup hostility. Study 1, conducted among 200 American Christians and Jews, reveals that under mortality salience, intrinsic (but not extrinsic or quest) religiosity is related to decreased support for aggressive counterterrorism. Study 2, conducted among 148 Muslims in Iran, demonstrates that intrinsic religiosity predicts decreased out‐group derogation under mortality salience. Study 3, conducted among 131 Polish Christians, shows that under mortality salience, priming of intrinsic religious concepts decreases support for aggressive counterterrorism. Copyright © 2012 John Wiley & Sons, Ltd.
Log‐jams and avulsions in the San Antonio River Delta, Texas
Authors: Phillips Jonathan D. 
Published: January 2012

ABSTRACTThe San Antonio River Delta (SARD), Texas, has experienced two major avulsions in the past 80 years, and a number of other historical and Holocene channel shifts. The causes and consequences of these avulsions – one of which is ongoing – were examined using a combination of fieldwork, geographic information system (GIS) analysis, and historical information to identify active, semi‐active, and paleochannels and the sequence of shifting flow paths through the delta. The role of deposition patterns and antecedent morphology, large woody debris jams, and tectonic influences were given special attention. Sedimentation in the SARD is exacerbated by tectonic effects. Channel aggradation is ubiquitous, and superelevation of the channel bed above the level of backswamp areas on the floodplain is common. This creates ideal setup conditions for avulsions, and stable, cohesive fine‐grained banks favor avulsions rather than lateral migration. Flood basins between the alluvial ridges associated with the aggraded channels exist, but avulsions occur by re‐occupation of former channels found within or connected to the flood basins. Large woody debris and channel‐blocking log‐jams are common, and sometimes displace flow from the channel, triggering crevasses. However, a large, recurring log‐jam at the site of the ongoing avulsion from the San Antonio River into Elm Bayou is not responsible for the channel shift. Rather, narrow, laterally stable channels resulting from flow splits lead to accumulation of wood. Some aspects of the SARD avulsion regime are typical of other deltas, while others are more novel. These includes avulsions involving tributaries and subchannels within the delta as well as from the dominant channel; tectonic influences on delta backstepping and on channel changes within the delta; avulsions as an indirect trigger for log‐jam formation (as well as vice‐versa); and maintenance of a multi‐channel flow pattern distinct from classic anastamosing or distributary systems. Copyright © 2012 John Wiley & Sons, Ltd.
Alterations of Smad expression and activation in defining 2 subtypes of human head and neck squamous cell carcinoma
Authors: Xie Wen , Aisner Seena , Baredes Soly , Sreepada Gangadhar , Shah Rasesh , Reiss Michael 
Published: January 2012

AbstractBackgroundWe postulated that disruptions of the canonical transforming growth factor‐beta (TGF‐β)/Smad signaling pathway might contribute to the development of head and neck squamous cell carcinoma (HNSCC).MethodsA cohort of 798 HNSCC tumor samples from 346 patients were analyzed by immunohistochemistry (IHC) to define the pattern of expression of (phospho)Smad2, (phospho)Smad3, and Smad4.ResultsWe found that 19%, 40%, and 12% of HNSCC specimens failed to express pSmad2, pSmad3, or Smad4, respectively. Loss of Smad2/3 activation was observed in 8.5% of specimens. In addition, 4% of specimens failed to express only Smad4. Moreover, patients with pSmad2/3‐negative tumors had a significantly better overall survival than that of those whose tumors expressed activated Smad2/3. In contrast, loss of Smad4 expression did not have prognostic significance.ConclusionOur results indicate that HNSCC in which Smad2/3 are inactivated or in which Smad4 expression is lost represent 2 distinct tumor subtypes with different clinical outcomes. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
The chronic spleen injury of mice following long‐term exposure to titanium dioxide nanoparticles
Authors: Sang Xuezi , Zheng Lei , Sun Qingqing , Li Na , Cui Yaling , Hu Renping , Gao Guodong , Cheng Zhe , Cheng Jie , Gui Suxin , Liu Huiting , Zhang Zengli , Hong Fashui 
Published: January 2012

AbstractTo understand the chronic spleen injury induced by intragastric administrations with 2.5, 5, and 10 mg kg−1 body weight titanium dioxide nanoparticles (TiO2 NPs) for 90 consecutive days, histopathological and ultrastructure changes, hematological parameters, lymphocyte subsets, the inflammatory, and apoptotic cytokines in the mouse spleen were investigated. Our findings indicate that TiO2 NPs exposure results in the significant increase in the spleen indices, histopathological changes, and splenocyte apoptosis in spleen. Especially, in these TiO2 NPs‐treated mice, immunoglobulin, blood cells, platelets, hemoglobin, lymphocyte subsets (such as CD3, CD4, CD8, B cell, natural killer cell) of mice were significantly decreased. Furthermore, TiO2 NPs exposure can significantly increase the levels of nucleic factor‐κB, tumor necrosis factor‐α, macrophage migration inhibitory factor, interleukin‐2, interleukin‐4, interleukin‐6, interleukin‐8, interleukin‐10, interleukin‐18, interleukin‐1β, cross‐reaction protein, transforming growth factor‐β, interferon‐γ, Bax, and CYP1A1 expression, whereas decrease the levels of Bcl‐2 and heat shock protein 70 expression. These findings suggest that long‐term exposure to low dose TiO2 NPs may result in spleen injury and reduction of immune capacity, TiO2 NP‐induced injury in spleen may result from alteration of inflammatory and apoptotic cytokines expression, and workers and consumers should take great caution when handling nanomaterials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Inhibition of IGF‐IR increases chemosensitivity in human colorectal cancer cells through MRP‐2 promoter suppression
Authors: Shen Ke , Cui Daling , Sun Liyun , Lu Yanhua , Han Mingquan , Liu Jianwen 
Published: January 2012

AbstractThe emergence of multidrug resistance (MDR) in cancer cells has made many of the currently available chemotherapeutic agents ineffective. However, the mechanism involved in mediating this effect is not yet fully understood. Here, we found the overexpression of type I insulin‐like growth factor receptor (IGF‐IR) in established colorectal MDR cells. Specific siRNA of IGF‐IR decreases cell proliferation, exert synergistic effect with anticancer drugs. The downstream signaling of IGF‐IR, PI3K/AKT pathway, was altered upon IGF‐IR silencing. The expression of multidrug‐resistance‐associated protein 2 (MRP‐2) was suppressed due to the nuclear translocation of nuclear factor‐like 2 (Nrf2). Then the intracellular drug concentration was increased and the drug‐resistant phenotype was reversed. Our findings improve current understanding of the biology of IGF‐IR and MDR and have significant therapeutic implications on colorectal MDR cancer. J. Cell. Biochem. 113: 2086–2097, 2012. © 2012 Wiley Periodicals, Inc.
EXTENDING ACCESS TO INFORMATION, EDUCATION AND ENTERTAINMENT IN THE DEVELOPING ECONOMIES: BROADCAST TECHNOLOGIES IN THE BRITISH EMPIRE, 1951 TO 1962
Authors: Bowden Sue , Clayton David , Pereira Alvaro 
Published: January 2012

AbstractThis paper builds on previous work published in this journal by considering the historical roots of poverty in relation to the denial or otherwise of access to the information made available by radio technology. The case study is that of the British Empire in the early post‐war years. New dimensions of access that are developing economy sensitive are presented and evaluated. We find that the colonial legacy of radio broadcast is significantly correlated with the diffusion and adoption of radio technologies in subsequent years and that this in terms was largely the reflection of geo‐political considerations. Differential access to information has its roots in the colonial historical past. Copyright © 2012 John Wiley & Sons, Ltd.
Bridging the gap between Gen X and Gen Y
Authors: Mhatre Ketan H. , Conger Jay A. 
Published: January 2012

AbstractThe implications of the generational diversity inherent in the fabric of the current workforce have been a topic of much discussion, exploration, and debate among organizational scholars and researchers. What are the leadership implications of this generational diversity, and what forms of leadership can be used constructively to achieve performance outcomes that foster a positive and constructive relationship between generations? We turn to the theoretical developments associated with the Authentic Leadership model to synthesize learning lessons from the theory, research, and practice of authentic leadership. We illustrate how the components of authentic leadership can help in overcoming some of the leadership challenges that result due to the differences between Gen Xers and Gen Yers.