bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational Switching in Heterochiral α,β2,3‐Hybrid Peptides in Response to Solvent Polarity
Authors: Balamurugan Dhayalan , Muraleedharan Kannoth M. 
Published: July 2015

AbstractThe ability of α,β2,3‐hybrid peptides with a heterochiral backbone to exist in a helical, extended, or partially folded state depending on the solvation conditions employed was investigated. The preference was found to be directly dictated by Cα–Cβ torsions in the β‐residues.
Substrate Activation in the Catalytic Asymmetric Hydrogenation ofN‐Heteroarenes
Authors: Balakrishna Bugga , Núñez‐Rico José Luis , Vidal‐Ferran Anton 
Published: July 2015

AbstractDifferent methods for transformingN‐heteroarenes into more reactive derivatives for catalytic asymmetric hydrogenation are highlighted. The first strategy consists of facilitating hydrogenation by the formation of positively charged derivatives of the heteroarene. Catalyst deactivation processes arising upon binding of the substrate to the metal center can thus be prevented and, additionally, hydrogenation of positively charged heteroarenes may also be more favored than that of their neutral analogues. The second strategy is based on introducing a ligating group onto the substrate to assist its coordination to the metal center and facilitate hydrogenation by chelation assistance. The last strategy involves breaking the aromaticity of the heteroarene by inducing a double‐bond migration process. This microreview summarizes advances made in the above strategies, which have allowed the development of highly enantioselective catalytic hydrogenation ofN‐heteroarenes for the production of fully or partially saturated chiral heterocycles.
Copper/Selectfluor‐System‐Catalyzed Dehydration–Oxidation of Tertiary Cyclo­alcohols: Access to β‐Substituted Cyclohex‐2‐enones, 4‐Arylcoumarins, and Bi­aryls
Authors: Ren Shaobo , Zhang Jian , Zhang Jiahui , Wang Heng , Zhang Wei , Liu Yunkui , Liu Miaochang 
Published: July 2015

AbstractA route to β‐substituted cyclohex‐2‐enones, 4‐arylcoumarins, and biaryls has been developed. This approach involves a one‐pot Cu0/Selectfluor‐catalyzed dehydration–oxidation of tertiary cycloalcohols. Thus, by using 2 equiv. of Selectfluor at 25 °C, the dehydration–oxidation of tertiary cyclohexanols and oxabenzocyclohexanols gave β‐substituted cyclohex‐2‐enones and 4‐arylcoumarins, respectively; whereas the dehydration–oxidation of tertiary cyclohexanols gave biaryls as the final products by using 2.5 equiv. of Selectfluor at 80 °C.
Domino Prins Cyclization of Enynols: Stereoselective Synthesis of Bicyclic Vinyl Fluorides
Authors: Venkateswarlu Anipireddy , Kanakaraju Marumudi. , Kunwar Ajit C. , Rami Reddy Yellala V. , Reddy Basi V. S. 
Published: July 2015

AbstractA fluoride‐induced termination of Prins cyclization has been observed using a tethered alkyne and stoichiometric amounts of AgSbF6 and found to generate a novel series of 6‐fluoro‐1‐aryl‐hexahydro‐1H‐isochromene derivatives in good yields with excellent selectivity. This is the first report of the synthesis of fluoro‐substituted oxabicycles. In this tandem process, three reactions occur in one‐pot to leading to installation of three contiguous stereocenters.
Chemical analysis of fish bile extracts for monitoring endocrine disrupting chemical exposure in water: Bisphenol A, alkylphenols, and norethindrone
Authors: Wu Minghong , Pan Chenyuan , Yang Ming , Xu Bentuo , Lei Xiangjie , Ma Jing , Cai Ling , Chen Jingsi 
Published: July 2015

Abstract

The present study determined concentrations of estrogenic bisphenol A (BPA), nonylphenol, octylphenol (4-tert-octylphenol), butylphenol (4-tert-butylphenol), and progestogenic norethindrone by liquid chromatography–tandem mass spectrometry in bile extracts from field fish from the Xin'an River and market fish in Shanghai, China. Compared with the field fish, endocrine disrupting chemical (EDC) concentrations in market fish bile were at relatively high levels with high detectable rates. The average concentrations of BPA, nonylphenol, 4-tert-octylphenol, 4-tert-butylphenol, and norethindrone in field fish bile were 30.1 µg/L, 203 µg/L, 4.69 µg/L, 7.84 µg/L, and 0.514 µg/L, respectively; in market fish bile they were 240 µg/L, 528 µg/L, 76.5 µg/L, 12.8 µg/L, and 5.26 µg/L, respectively; and in the surface water of Xin'an River they were 38.8 ng/L, 7.91 ng/L, 1.98 ng/L, 2.66 ng/L, and 0.116 ng/L, respectively. The average of total estrogenic activity of river water was 3.32 ng/L estradiol equivalents. High bioconcentration factors (BCFs) were discovered for all 5 EDCs (≧998-fold) in field fish bile. Furthermore, the authors analyzed the BCF value of BPA in fish bile after 30-d exposure to environmentally relevant concentrations of BPA in the laboratory, and the analysis revealed that BCF in fish bile (BCFFish bile) changed in an inverse concentration–dependent manner based on the log10-transformed BPA concentration in water. Strikingly, the data from the field study were well fitted within this trend. The data together suggested that analysis of fish bile extracts could be an efficient method for assessing waterborne EDCs exposure for aquatic biota. Environ Toxicol Chem 2016;35:182–190. © 2015 SETAC
Backhaul aware joint uplink and downlink user association for delay‐power trade‐offs in HetNets with hybrid energy sources
Authors: Liu Dantong , Chen Yue , Chai Kok Keong , Zhang Tiankui 
Published: July 2015

AbstractIn cellular networks, conventional user association algorithms are solely based on downlink (DL) performance, which may lead to inefficient transmission power and high interference in the uplink (UL) transmission. In addition, the backhaul data rate constraint has been neglected by the majority of the existing user association algorithms. However, the backhaul constraint has become more severe in heterogeneous networks (HetNets) where small cells are densely deployed to meet the skyrocketing data traffic demand. In this paper, we propose an optimal backhaul‐aware joint UL and DL user association for delay‐power trade‐offs in HetNets with hybrid energy sources. In the considered HetNets, all the base stations are assumed to be powered by a combination of power grid and renewable energy sources, in order to achieve both uninterrupted and green communications. Taking both UL and DL transmissions into consideration, the proposed user association algorithm aims to improve network quality of service by minimising the sum of UL and DL average traffic delay, as well as to reduce the overall UL power consumption of users and DL on‐grid power consumption by maximising the utilisation of green power harvested from renewable energy sources. To this end, a convex optimisation problem is formulated to minimise the weighted sum of cost of average traffic delay and cost of power consumption. We have proved that the proposed user association algorithm converges to the global optimum, which enables a flexible trade‐off between average traffic delay and power consumption. Simulation results validate the effectiveness of the proposed algorithm in adapting the traffic loads among base stations along with the distribution of green power and the backhaul data rate constraint. Simulation results also demonstrate that the proposed user association algorithm achieves prominent improvement in UL average traffic delay reduction and effectively reduces both the DL on‐grid power consumption and overall UL power consumption of users, with limited sacrifice on DL average traffic delay, compared with the user association algorithm only based on DL performance. Copyright © 2015 John Wiley & Sons, Ltd.
Modelling groundwater/surface water interaction in a managed riparian chalk valley wetland
Authors: House A. R. , Thompson J. R. , Sorensen J. P. R. , Roberts C. , Acreman M. C. 
Published: July 2015

AbstractUnderstanding hydrological processes in wetlands may be complicated by management practices and complex groundwater/surface water interactions. This is especially true for wetlands underlain by permeable geology, such as chalk. In this study, the physically based, distributed model MIKE SHE is used to simulate hydrological processes at the Centre for Ecology and Hydrology River Lambourn Observatory, Boxford, Berkshire, UK. This comprises a 10‐ha lowland, chalk valley bottom, riparian wetland designated for its conservation value and scientific interest. Channel management and a compound geology exert important, but to date not completely understood, influences upon hydrological conditions. Model calibration and validation were based upon comparisons of observed and simulated groundwater heads and channel stages over an equally split 20‐month period. Model results are generally consistent with field observations and include short‐term responses to events as well as longer‐term seasonal trends. An intrinsic difficulty in representing compressible, anisotropic soils limited otherwise excellent performance in some areas. Hydrological processes in the wetland are dominated by the interaction between groundwater and surface water. Channel stage provides head boundaries for broad water levels across the wetland, whilst areas of groundwater upwelling control discrete head elevations. A relic surface drainage network confines flooding extents and routes seepage to the main channels. In‐channel macrophyte growth and its management have an acute effect on water levels and the proportional contribution of groundwater and surface water. The implications of model results for management of conservation species and their associated habitats are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Proposed human stratum corneum water domain in chemical absorption
Authors: Zhu Hanjiang , Jung Eui‐Chang , Hui Xiaoying , Maibach Howard 
Published: July 2015

AbstractCompounds with varying physical and chemical properties may have different affinities to the stratum corneum (SC) and/or its intercellular lipids, keratin protein, and possible water domains. To better understand the mechanism of percutaneous absorption, we utilized 21 carbon‐14 labeled chemicals, with wide hydrophilicity (log P = −0.05 to 6.17), and quantified their absorption/adsorption properties for a short incubation time (15 min) with regards to intact SC membrane, delipidized SC membrane and SC lipid. A facile method was developed for SC/lipid absorption, providing a more equivalent procedure and comparable data. SC lipid absorption of chemical solutes positively correlated with the octanol/water partition coefficient (log P). Differences between the percent dose of chemical absorption to intact SC and the total percent dose contributed by the protein and lipid domains suggest the possibility and significance of a water domain. Absorption rate experiments showed a longer lag time for intact SC than for delipidized SC or SC lipid, suggesting that the water domain may delay chemical binding to protein and lipid domains, and may be a factor in the resistance of many chemicals to current decontamination methods. Copyright © 2015 John Wiley & Sons, Ltd.
MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?
Authors: Schenberg Tess , Mitchell Gillian , Taylor Donna , Saunders Christobel 
Published: July 2015

AbstractBreast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare‐funded breast MRI screening in Australia. Issues discussed will include selection of high‐risk women, the options for MRI screening frequency and measuring the outcomes of screening.
A Combinatorial Photocrosslinking Method for the Preparation of Porous Structures with Widely Differing Properties
Authors: Zant Erwin , Blokzijl Maarten M. , Grijpma Dirk W. 
Published: July 2015

A novel method for the simultaneous preparation of a large number of porous polymeric structures with highly differing physical properties is developed. Low molecular weight methacrylate end‐functionalized polymers (macromers) are dissolved in ethylene carbonate, cooled to below the melting temperature of the solvent, and subsequently photocrosslinked. The crystallized and phase‐separated ethylene carbonate is extracted with water, upon which a porous crosslinked polymer network is obtained. The method is applied to combinatorial mixtures of methacrylate end‐functionalized polymers that are relevant in the biomedical field: poly(trimethylene carbonate‐dimethacrylate), poly(D,L‐lactide‐dimethacrylate), and poly(ethylene glycol‐dimethacrylate) dissolved in ethylene carbonate at concentrations of approximately 25 wt%. In this manner, 63 different porous polymeric structures with a very wide range of physical properties are prepared simultaneously. In the hydrated state the compressive moduli of the prepared structures range from 0.01 to 60 MPa, as water uptake ranges between 3 and 1500 wt%.
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Comparison of in‐flight aircraft icing algorithms based on ECMWF forecasts
Authors: Belo‐Pereira Margarida 
Published: July 2015

ABSTRACTThis study presents an objective verification of different icing algorithms for two periods from 5 December 2012 to 17 April 2013 and from 9 October to 11 December 2013. The predicted icing potential and severity are evaluated against pilot reports of aircraft icing below 23 000 feet over Eastern United States. The icing algorithms are applied to the deterministic forecasts of European Centre for Medium‐Range Weather Forecasts (ECMWF). Two of these algorithms are based only on forecasts of temperature (T) and relative humidity (RH), but the first uses fixed thresholds and the second uses a fuzzy logic approach. Although the second algorithm detects less icing events, it is more efficient with respect to the warning area, i.e. it forecasts icing over a smaller percentage of the airspace than the first algorithm. The impact of adding information from cloud liquid water (CLW) content and/or vertical velocity in the fuzzy logic scheme is assessed. Algorithms using T, CLW and vertical velocity as predictors are also tested. Most of the algorithms reveal a good performance in discriminating between icing and no‐icing conditions, but are less skilful in forecasting the icing severity. The results also show that the use of CLW is essential to avoid issuing too many warnings. Moreover, the algorithm combining T, RH, CLW and vertical velocity attains the best performance. This algorithm, SFIPO, has been operational at the Portuguese Meteorological Watch Office since June 2013, and an example of a severe icing episode in February 2014 over mainland Portugal is presented.
Pred‐hERG: A Novel web‐Accessible Computational Tool for Predicting Cardiac Toxicity
Authors: Braga Rodolpho C. , Alves Vinicius M. , Silva Meryck F. B. , Muratov Eugene , Fourches Denis , Lião Luciano M. , Tropsha Alexander , Andrade Carolina H. 
Published: July 2015

AbstractThe blockage of the hERG K+ channels is closely associated with lethal cardiac arrhythmia. The notorious ligand promiscuity of this channel earmarked hERG as one of the most important antitargets to be considered in early stages of drug development process. Herein we report on the development of an innovative and freely accessible web server for early identification of putative hERG blockers and non‐blockers in chemical libraries. We have collected the largest publicly available curated hERG dataset of 5,984 compounds. We succeed in developing robust and externally predictive binary (CCR≈0.8) and multiclass models (accuracy≈0.7). These models are available as a web‐service freely available for public at http://labmol.farmacia.ufg.br/predherg/. Three following outcomes are available for the users: prediction by binary model, prediction by multi‐class model, and the probability maps of atomic contribution. The Pred‐hERG will be continuously updated and upgraded as new information became available.
Virtual screening of a milk peptide database for the identification of food‐derived antimicrobial peptides
Authors: Liu Yufang , Eichler Jutta , Pischetsrieder Monika 
Published: July 2015

ScopeMilk provides a wide range of bioactive substances, such as antimicrobial peptides and proteins. Our study aimed to identify novel antimicrobial peptides naturally present in milk.Methods and resultsThe components of an endogenous bovine milk peptide database were virtually screened for charge, amphipathy, and predicted secondary structure. Thus, 23 of 248 screened peptides were identified as candidates for antimicrobial effects. After commercial synthesis, their antimicrobial activities were determined against Escherichia coli NEB5α, E. coli ATCC25922, and Bacillus subtilis ATCC6051. In the tested concentration range (<2 mM), bacteriostatic activity of 14 peptides was detected including nine peptides inhibiting both Gram‐positive and Gram‐negative bacteria. The most effective fragment was TKLTEEEKNRLNFLKKISQRYQKFΑLPQYLK corresponding to αS2‐casein151–181, with minimum inhibitory concentration (MIC) of 4.0 μM against B. subtilis ATCC6051, and minimum inhibitory concentrations of 16.2 μM against both E. coli strains. Circular dichroism spectroscopy revealed conformational changes of most active peptides in a membrane‐mimic environment, transitioning from an unordered to α‐helical structure.ConclusionScreening of food peptide databases by prediction tools is an efficient method to identify novel antimicrobial food‐derived peptides. Milk‐derived antimicrobial peptides may have potential use as functional food ingredients and help to understand the molecular mechanisms of anti‐infective milk effects.
Alleviation of high fat diet‐induced obesity by oligofructose in gnotobiotic mice is independent of presence of Bifidobacterium longum
Authors: Woting Anni , Pfeiffer Nora , Hanske Laura , Loh Gunnar , Klaus Susanne , Blaut Michael 
Published: July 2015

ScopeDiet‐induced obesity is associated with changes in the gut microbiota and low‐grade inflammation. Oligofructose was reported to ameliorate high fat diet‐induced metabolic disorders in mice by restoring the number of intestinal bifidobacteria. However, this has not been experimentally demonstrated.Methods and resultsWe fed conventional mice, germfree mice, mice associated with a simplified human gut microbiota composed of eight bacterial species including Bifidobacterium longum (SIHUMI), and mice associated with SIHUMI without B. longum a low fat diet (LFD), a high fat diet (HFD), or a HFD containing 10% oligofructose (HFD + OFS) for five weeks. We assessed body composition, bacterial cell numbers and metabolites, markers of inflammation, and gut permeability. Conventional mice fed HFD or HFD + OFS did not differ in body weight gain and glucose tolerance. The gnotobiotic mouse groups fed LFD or HFD + OFS gained less body weight and body fat, and displayed an improved glucose tolerance compared with mice fed HFD. These differences were not affected by the presence of B. longum. Mice fed HFD showed no signs of inflammation or increased intestinal permeability.ConclusionThe ability of oligofructose to reduce obesity and to improve glucose tolerance in gnotobiotic mice fed HFD was independent of the presence of B. longum.
Gel‐free mass spectrometry analysis of Drosophila melanogaster heads
Authors: Aradska Jana , Bulat Tanja , Sialana Fernando J. , Birner‐Gruenberger Ruth , Erich Buchner , Lubec Gert 
Published: July 2015

Membrane proteins play key roles in several fundamental biological processes such as cell signalling, energy metabolism and transport. Despite the significance, these still remain an under‐represented group in proteomics datasets. Herein, a bottom‐up approach to analyse an enriched membrane fraction from Drosophila melanogaster heads using multidimensional liquid chromatography (LC) coupled with tandem‐mass spectrometry (MS/MS) that relies on complete solubilisation and digestion of proteins, is reported. An enriched membrane fraction was prepared using equilibrium density centrifugation on a discontinuous sucrose gradient, followed by solubilisation using the filter‐aided sample preparation (FASP), tryptic and sequential chymotryptic digestion of proteins. Peptides were separated by reversed‐phase (RP) LC at high pH in the first dimension and acidic RP‐LC in the second dimension coupled directly to an Orbitrap Velos Pro mass spectrometer. A total number of 4812 proteins from 114 865 redundant and 38 179 distinct peptides corresponding to 4559 genes were identified in the enriched membrane fraction from fly heads. These included brain receptors, transporters and channels that are most important elements as drug targets or are linked to disease. Data are available via ProteomeXchange with identifier PXD001712 (http://proteomecentral.proteomexchange.org/dataset/PXD001712).
Grain boundary recombination in semiconductors: the grain boundary interaction case
Authors: Tarento René‐Jean , Mekki Djamel‐Eddine 
Published: July 2015

AbstractThe recombination velocity and the barrier height at a grain boundary are investigated with respect to the interaction between two parallel grain boundaries. A self‐consistent calculation has been performed within the Read‐Hall‐Shockley framework. The procedure takes into account of the space‐charge region and the quasi‐neutral region assuming a rigid displacement of the bands. The grain‐boundary energy states are considered in the half‐filled‐level model. The dependence of the recombination parameters are reported versus the excitation and the semiconductor and grain‐boundary characteristics. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain and carrier transport along dislocations
Authors: Reiche Manfred , Kittler Martin , Pippel Eckhard , Erfurth Winfried , Haehnel Angelika , Uebensee Hartmut 
Published: July 2015

AbstractA significant increase of the drain current is verified if defined numbers and types of dislocations are present in the channel of MOSFETs. For pMOSFETs, analysed here, an enhancement by a factor of eight exists if mixed dislocations are placed in the channel. The drain current increase is caused by higher concentration and higher mobility of holes on dislocations. It is shown that cores of mixed dislocations possess uniaxial compressive strain components in the order of ε ≅ –0.1 which are significantly higher than in the strain field surrounding a dislocation. The exceptional high uniaxial strain results in dramatic alterations of the silicon band structure. Upward shifts of the upper valence bands appear forming a quantum wire. The generation of the quantum wire forces hole confinement along dislocations and generates a one‐dimensional hole gas (1DHG). Confinement and energy quantization are assumed to be most important for the increased carrier transport along dislocations. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)