bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intermolecular Hydroamination of Vinylarenes by Iminoanilide Alkaline‐Earth Catalysts: A Computational Scrutiny of Mechanistic Pathways
Authors: Tobisch Sven 
Published: June 2014

AbstractA thorough computational exploration of the mechanistic intricacies of the intermolecular hydroamination (HA) of vinylarenes by a recently reported class of kinetically stabilised iminoanilide [{N^N}Ae{N(SiMe3)2}⋅(THF)n] alkaline‐earth amido compounds (Ae=Ca, Sr, Ba) is presented. Two distinct mechanistic pathways for catalytic HA mediated by alkaline‐earth and rare‐earth compounds have emerged over the years that account equally well for the specific features of the process. On one hand, a concerted proton‐assisted pathway to deliver the amine product in a single step can be invoked and, on the other, a stepwise σ‐insertive pathway that comprises a rapid, reversible migratory olefin insertion step linked to a less facile, irreversible AeC alkyl bond aminolysis. The results of the study presented herein, which employed a heavily benchmarked and reliable DFT methodology, supports a stepwise σ‐insertive pathway that involves fast and reversible migratory CC bond insertion into the polar AeN pyrrolido σ bond. This proceeds with strict 2,1 regioselectivity via a highly polarised four‐centre transition state (TS) structure, linked to irreversible intramolecular AeC bond aminolysis of the alkaline‐earth alkyl intermediate as the energetically favourable mechanism. Turnover‐limiting aminolysis is consistent with the significant KIE measured; the DFT‐derived effective barrier matches the Eyring parameter empirically determined for the best‐performing {N^N}Ba(NR2) catalyst gratifyingly well. It also predicts the observed trend in reactivity (Ca<Sr<Ba) correctly and the computationally estimated primary KIE is close to the observed values. Non‐competitive kinetic demands militate against the operation of the alternative concerted proton‐assisted pathway, which describes NC bond formation triggered by concomitant amino proton transfer at the CC linkage via a multi‐centre TS structure. A detailed comparison of {N^N}Ae(NR2) catalysts revealed that the variation in the Aepyrrolido bond strength together with the degree of protection of the alkaline earth by a sterically encumbering iminoanilide ligand scaffold not only profoundly influences the performance in HA catalysis, but also the likelihood of traversing rival mechanistic pathways.
Cell type–specific spatial and functional coupling between mammalian brain Kv2.1 K+ channels and ryanodine receptors
Authors: Mandikian Danielle , Bocksteins Elke , Parajuli Laxmi Kumar , Bishop Hannah I. , Cerda Oscar , Shigemoto Ryuichi , Trimmer James S. 
Published: June 2014

ABSTRACTThe Kv2.1 voltage‐gated K+ channel is widely expressed throughout mammalian brain, where it contributes to dynamic activity‐dependent regulation of intrinsic neuronal excitability. Here we show that somatic plasma membrane Kv2.1 clusters are juxtaposed to clusters of intracellular ryanodine receptor (RyR) Ca2+‐release channels in mouse brain neurons, most prominently in medium spiny neurons (MSNs) of the striatum. Electron microscopy–immunogold labeling shows that in MSNs, plasma membrane Kv2.1 clusters are adjacent to subsurface cisternae, placing Kv2.1 in close proximity to sites of RyR‐mediated Ca2+ release. Immunofluorescence labeling in transgenic mice expressing green fluorescent protein in specific MSN populations reveals the most prominent juxtaposed Kv2.1:RyR clusters in indirect pathway MSNs. Kv2.1 in both direct and indirect pathway MSNs exhibits markedly lower levels of labeling with phosphospecific antibodies directed against the S453, S563, and S603 phosphorylation site compared with levels observed in neocortical neurons, although labeling for Kv2.1 phosphorylation at S563 was significantly lower in indirect pathway MSNs compared with those in the direct pathway. Finally, acute stimulation of RyRs in heterologous cells causes a rapid hyperpolarizing shift in the voltage dependence of activation of Kv2.1, typical of Ca2+/calcineurin‐dependent Kv2.1 dephosphorylation. Together, these studies reveal that striatal MSNs are distinct in their expression of clustered Kv2.1 at plasma membrane sites juxtaposed to intracellular RyRs, as well as in Kv2.1 phosphorylation state. Differences in Kv2.1 expression and phosphorylation between MSNs in direct and indirect pathways provide a cell‐ and circuit‐specific mechanism for coupling intracellular Ca2+ release to phosphorylation‐dependent regulation of Kv2.1 to dynamically impact intrinsic excitability. J. Comp. Neurol. 522:3555–3574, 2014. © 2014 Wiley Periodicals, Inc.
Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management
Authors: Evans Thomas , Kumschick Sabrina , Dyer Ellie , Blackburn Tim 
Published: June 2014

AbstractInvasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self‐sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions.
A Catalytic System for the Activation of Diorganozinc Reagents
Authors: Werner Thomas , Bauer Matthias , Riahi Abdol Majid , Schramm Heiko 
Published: June 2014

AbstractWe report a novel catalytic system for the activation of diorganozinc reagents. We assumed that the nucleophilic activation of diethylzinc should be efficiently performed by simple alkali metal salts. Indeed, the combination of sodium salts and 15‐crown‐5 significantly accelerates the rate of diethylzinc addition to benzaldehyde under mild conditions. The activity of the catalytic system strongly depends on the nature of the anion, decreasing in the order I– > Br– > Cl– > F–. Under the optimized reaction conditions, various aryl, hetero aryl, and aliphatic aldehydes were converted with diethylzinc and the corresponding product was obtained in excellent yields. The first X‐ray absorption spectroscopy measurements on such type of reactions provide initial insights that support the proposed catalytic cycle and suggest the formation of a zincate complex.
Hypervalent Iodine(III)‐Promoted Metal‐Free S–H Activation: An Approach for the Construction of S–S, S–N, and S–C Bonds
Authors: Rattanangkool Eakkaphon , Krailat Watanya , Vilaivan Tirayut , Phuwapraisirisan Preecha , Sukwattanasinitt Mongkol , Wacharasindhu Sumrit 
Published: June 2014

AbstractThe activation of the sulfur atom of thiols with (diacetoxyiodo)benzene (DIB) has been explored in the preparation of symmetrical disulfides and sulfenamides. Disulfides can be produced in excellent yields (75–95 %) upon treatment of thiols with DIB. The reaction was complete in less than five minutes at room temperature. Aliphatic, aromatic, and heteroaromatic thiols are compatible with this transformation. Moreover, heteroaromatic disulfides obtained from heteroaromatic thiols further reacted with a nucleophilic amine in the presence of a base to provide the corresponding sulfenamides in fair to good yields (43–90 %) in a one‐pot fashion. The methodology was successfully extended to indole as a representative electron‐rich aromatic compound, which allowed successful construction of a S–C bond in one pot. The key benefits of this reaction include lower toxicity, low cost of DIB reagent, and mild reaction conditions (room temperature, undried solvents and open flask).
Imidazolidinone Nitroxides as Catalysts in the Aerobic Oxidation of Alcohols, en Route to Atroposelective Oxidative Desymmetrization
Authors: Carbó López Marta , Royal Guy , Philouze Christian , Chavant Pierre Y. , Blandin Véronique 
Published: June 2014

AbstractNew chiral nitroxides based on the imidazolidin‐4‐one skeleton, and the corresponding hydroxylamines, have been prepared from cyclic nitrones by a straightforward reaction sequence. They were evaluated as catalysts in the aerobic oxidation of benzyl alcohol using different co‐catalysts. Both the imidazolidinone nitroxides and hydroxylamines were proven to catalyze the reaction, with the ring substituent having an effect depending on the co‐catalytic system. In some cases, rapid oxidation to benzaldehyde was accomplished at room temperature under an atmospheric O2 pressure. Moreover, atroposelective desymmetrization was achieved during the aerobic oxidation of a diol catalyzed by an enantiopure imidazolidinone nitroxide. Finally, the electrochemical behavior of the new hydroxylamines and nitroxides was investigated by cyclic voltammetry, which gave insights into the observed catalytic properties.
Stereoselective Approach to 2,6‐Disubstituted Piperidin‐3‐ol: Synthesis of (–)‐Deoxoprosopinine and (+)‐Deoxoprosophylline
Authors: Jha Vishwajeet , Kauloorkar Shruti Vandana , Kumar Pradeep 
Published: June 2014

AbstractA simple and highly efficient approach to an enantioenriched 2,6‐disubstituted piperidin‐3‐ol skeleton is developed from an aldehyde as a starting material by using organocatalytic and asymmetric dihydroxylation as the key steps. Its application to the total synthesis of (–)‐deoxoprosopinine and (+)‐deoxoprosophylline is also reported.
Efficient and Reusable CuI/1,10‐Phenanthroline‐Catalyzed Oxidative Decarboxylative Homocoupling of Arylpropiolic Acids in Aqueous DMF
Authors: Liu De‐Xian , Li Fei‐Long , Li Hong‐Xi , Gong Wei‐Jie , Gao Jun , Lang Jian‐Ping 
Published: June 2014

AbstractAn efficient method for synthesis of 1,3‐diynes through the CuI/1,10‐phenanthroline‐catalyzed oxidative decarboxylative homocoupling of aryl pioprolic acids in aqueous DMF has been developed. The catalytic system was suitable for a variety of arylpropiolic acids, and the corresponding 1,3‐diynes could be prepared in high yields. The catalytic system was recovered from the organic products by filtration and its aqueous DMF filtrate retained good activity even after at least four cycles of use.
Synthesis, Solid‐State Analyses, and Anion‐Binding Properties of meso‐Aryldipyrrin‐5,5′‐diylbis(phenol) and ‐bis(aniline) Ligands
Authors: Copey Laurent , Jean‐Gérard Ludivine , Framery Eric , Pilet Guillaume , Andrioletti Bruno 
Published: June 2014

AbstractThe design of new molecular scaffolds for the selective recognition or transport of anions is often critical, because subtle changes in the substitution pattern may drastically impact the targeted properties. Herein, detailed spectroscopic and X‐ray crystal‐structure analyses were used to investigate the effect of the substitution pattern of a new series of N2O2 or N4 anion sensors. Our study evidences two distinct in‐in and in‐out conformations depending on the nature of the substituent (e.g., phenol vs. aniline). Interestingly, because of intramolecular hydrogen bonds involving the –OH or the –NH2 functions, the dipyrrin subunit only acts as a scaffold and does not participate in the anion binding. Furthermore, the nature of the meso substituent was not critical, as similar binding affinities were measured for meso‐C6H5 or meso‐C6F5 ligands. Hence, the meso position can be further modified without any noticeable changes to the electron density on the dipyrromethene subunit.
Sterically Controlled Diels–Alder Cycloadditions: Rapid Entry into the Illudin Scaffold
Authors: Stevens‐Cullinane Lars , Lucas Nigel T. , Hawkins Bill C. 
Published: June 2014

AbstractRapid entry into the tricyclic ring system of the illudin family of natural products was achieved using a Diels–Alder cycloaddition of allylidenecyclopropane 7 and various cyclic and acyclic dienophiles. The reaction proceeds with complete regioselectivity and moderate to high stereoselectivity in good to excellent chemical yields.
Rapid and Structurally Diverse Synthesis of Multi‐Substituted β‐Keto Amide Derivatives Based on a Dioxinone Scaffold
Authors: Fuse Shinichiro , Yoshida Hayato , Oosumi Kazuya , Takahashi Takashi 
Published: June 2014

AbstractA sequential diversification approach for the synthesis of various multi‐substituted β‐keto amide derivatives based on a simple and readily available dioxinone scaffold was developed. The process involves: (1) nucleophilic addition of the scaffold to an aldehyde, and a subsequent one‐pot dehydration; (2) palladium‐catalysed cross‐coupling of the scaffold with either an arylboronic acid pinacol ester, or CO and an aliphatic amine; and (3) nucleophilic addition of either an aliphatic amine or an arylamine, or a hetero‐Diels–Alder reaction of isocyanate/isothiocyanate, with an acylketene generated in situ from the dioxinone scaffold.
Electrochemical Detection of Persulfate at the Modified Glassy Carbon Electrode with Nanocomposite Containing Nano‐Ruthenium Oxide/Thionine and Nano‐Ruthenium Oxide/Celestine Blue
Authors: Roushani Mahmoud , Karami Elham 
Published: June 2014

AbstractThe present study describes the fabrication of a sensitive amperometric sensor for the determination of persulfate. The immobilization surface was prepared by modifying a glassy carbon (GC) electrode with a nanocomposite containing ruthenium oxide (RuOx) nanoparticles and thionine (TH) or celestin blue (CB). The modified electrodes indicated excellent electrocatalytic activity toward persulfate reduction at a potential of +0.1 V. The proposed sensor showed detection limits of 1.46 µM for the GC/RuOx/TH modified electrode and 2.64 µM for the GC/RuOx/CB modified electrode. The sensitivities were obtained as 3 nA µM−1 at a concentration range of 10 µM to 11 mM for the GC/RuOx/TH modified electrode and 1 nA µM−1 at a concentration range of 10 µM to 6 mM for the GC/RuOx/CB modified electrodes.
Executive Functioning in Overweight Individuals with and without Loss‐of‐Control Eating
Authors: Manasse Stephanie M. , Juarascio Adrienne S. , Forman Evan M. , Berner Laura A. , Butryn Meghan L. , Ruocco Anthony C. 
Published: June 2014

AbstractObjectiveThe current study sought to examine executive function (EF) in overweight individuals with and without loss‐of‐control (LOC) eating.MethodEighty overweight and obese individuals entering a behavioural weight loss trial with (n = 18) and without (n = 62) LOC eating were administered a clinical interview and neuropsychological battery designed to assess self‐regulatory control, planning, delayed discounting and working memory.ResultsAfter controlling for age, IQ and depression, individuals with LOC eating performed worse on tasks of planning and self‐regulatory control and did not differ in performance on other tasks.DiscussionResults indicate that overweight individuals with LOC eating display relative deficits in EF compared with overweight individuals without LOC eating. Planning and self‐regulatory control deficits in particular may contribute to dysregulated eating patterns, increasing susceptibility to LOC episodes. Future research should examine how EF deficits relate to treatment outcome. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.
Detection ranges and uncertainty of passive Radio Frequency Identification (RFID) transponders for sediment tracking in gravel rivers and coastal environments
Authors: Chapuis Margot , Bright Christina J. , Hufnagel John , MacVicar Bruce 
Published: June 2014

ABSTRACTSince the earliest use of this technology, a growing number of researchers have employed passive Radio Frequency Identification (RFID) transponders to track sediment transport in gravel rivers and coastal environments. RFID transponders are advantageous because they are inexpensive, durable and use unique codes that allow sediment particle mobility and displacement to be assessed on a clast‐by‐clast basis. Despite these advantages, this technology is in need of a rigorous error and detection analysis. Many studies work with a precision of ~1 m, which is insufficient for some applications, and signal shadowing can occur due to clustering of tagged particles. Information on in‐field performance is also incomplete with respect to burial and submergence, especially for different transponders and antennae combinations. The objectives of this study are to qualify and quantify the factors that influence the detection zone of RFID tracers including antenna type, transponder size, transponder orientation, burial depth, submergence and clustering. Results of this study show that the detection zone is complex in shape due to a set of lobes in the detection field and provide a better understanding of transponder detection shape for different RFID transponder/antenna combinations. This study highlights a strong influence of clustering and submergence, but no significant effect of burial. Finally we propose standard operating procedures for tagging and tracking in rivers and coastal environments. Copyright © 2014 John Wiley & Sons, Ltd.
Primary care providers' bereavement care practices: recommendations for research directions
Authors: Ghesquiere Angela R. , Patel Sapana R. , Kaplan Daniel B. , Bruce Martha L. 
Published: June 2014

ObjectiveBereaved patients are often seen in primary care settings. Although most do not require formal support, physicians may be called upon to provide support to some bereaved, particularly those with bereavement‐related mental health disorders like complicated grief and bereavement‐related depression. Research evidence on physician bereavement care is scant. We make recommendations for future research in this area.DesignLiterature review focuses on studies conducted between 1996 and 2013 in the United States. Searches of Medline and PsychInfo, along with hand searches of reference sections, were conducted.ResultsThe limited existing research indicates substantial gaps in the research literature, especially in the areas of primary care physician skill and capacity, patient‐level outcomes, and the quality of research methodology. No US studies have focused specifically on care for bereavement‐related mental health disorders. We provide recommendations about how to improve research about primary care bereavement care.ConclusionsThe primary care sector offers ample opportunities for research on bereavement care. With greater research efforts, there may be improvements to quality of bereavement care in primary care, in general, and also to the accurate detection and appropriate referral for bereavement‐related mental health conditions. Copyright © 2014 John Wiley & Sons, Ltd.
Transformation of RN=CHPh to R(R′3Si)NCH2Ph in the Catalytic Desulfurization of Secondary Thioamide with R′3SiH Promoted by an Iron Complex
Authors: Fukumoto Kozo , Sakai Akane , Murai Toshiaki , Nakazawa Hiroshi 
Published: June 2014

ABSTRACTThe reaction of imine (RN=CHPh) with hydrosilane (R′3SiH) in the presence of CpFe(CO)2Me (1) revealed the formation of a hydrosilylation product (R(R′3Si)NCH2Ph). The findings helped us to understand the reaction mechanism of desulfurization of secondary thioamide catalyzed by 1 to give the corresponding imine and amine as a major and minor product, respectively.
Conceptual and numerical models for groundwater flow in an arid inland river basin
Authors: Yao Yingying , Zheng Chunmiao , Liu Jie , Cao Guoliang , Xiao Honglang , Li Haitao , Li Wenpeng 
Published: June 2014

AbstractThe Heihe River Basin (HRB) is an inland watershed in northwest China with a total area of approximately 130,000 km2, stretching from the Qilian Mountains in the south to the oases and agricultural fields in the middle and further to the Gobi desert in the north bordering Mongolia. As part of a major ecohydrological research initiative to provide a stronger scientific underpinning for sustainable water management in arid ecosystems, a regional‐scale integrated ecological and hydrological model is being developed, incorporating the knowledge based on the results of environmental isotope tracer analysis and the multiscale observation datasets. The first step in the model development effort is to construct and calibrate a groundwater flow model for the middle and lower HRB where the oases and vegetation along the Heihe river corridor are highly dependent on groundwater. In this study, the software tool ‘Arc Hydro Groundwater’ is used to build and visualize a hydrogeological data model for the HRB that links all relevant spatiotemporal hydrogeological data in a unified geodatabase within the ArcGIS environment. From the conceptual model, a regional‐scale groundwater flow model has been developed using MODFLOW‐2005. Critical considerations in developing the flow model include the representation of mountainous terrains and fluvial valleys by individual model layers, treatment of aquifer heterogeneities across multiple scales and selection of proper observation data and boundary conditions for model calibration. This paper discusses these issues in the context of the Heihe River Basin, but the results and insights from this study will have important implications for other large, regional groundwater modelling studies, especially in arid and semiarid inland river basins. Copyright © 2014 John Wiley & Sons, Ltd.
Glycated Collagen Induces α11 Integrin Expression Through TGF‐β2 and Smad3
Authors: Talior‐Volodarsky Ilana , Arora Pamma D. , Wang Yongqiang , Zeltz Cédric , Connelly Kim A. , Gullberg Donald , McCulloch Christopher A. 
Published: June 2014

AbstractThe adhesion of cardiac fibroblasts to the glycated collagen interstitium in diabetics is associated with de novo expression of the α11 integrin, myofibroblast formation and cardiac fibrosis. We examined how methylglyoxal‐glycated collagen regulates α11 integrin expression. In cardiac fibroblasts plated on glycated collagen but not glycated fibronectin, there was markedly increased α11 integrin and α‐smooth muscle actin expression. Compared with native collagen, binding of purified α11β1 integrin to glycated collagen was reduced by >fourfold, which was consistent with reduced fibroblast attachment to glycated collagen. Glycated collagen strongly enhanced the expression of TGF‐β2 but not TGF‐β1 or TGF‐β3. The increased expression of TGF‐β2 was inhibited by triple helical collagen peptides that mimic the α11β1 integrin binding site on type I collagen. In cardiac fibroblasts transfected with α11 integrin luciferase promoter constructs, glycated collagen activated the α11 integrin promoter. Analysis of α11 integrin promoter truncation mutants showed a novel Smad2/3 binding site located between −809 and −1300 nt that was required for promoter activation. We conclude that glycated collagen in the cardiac interstitium triggers an autocrine TGF‐β2 signaling pathway that stimulates α11 integrin expression through Smad2/3 binding elements in the α11 integrin promoter, which is important for myofibroblast formation and fibrosis. J. Cell. Physiol. 230: 327–336, 2015. © 2014 Wiley Periodicals, Inc.