bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rotationally Restricted 1,1′‐Bis­(phenylethynyl)ferrocene Subunits in Macrocycles
Authors: Hoffmann Viktor , Jenny Nicolas , Häussinger Daniel , Neuburger Markus , Mayor Marcel 
Published: April 2016

AbstractThe synthesis of macrocycles comprising a 1,1′‐bis(phenylethynyl)ferrocene subunit was developed to increase the structural control over the spatial arrangement of the two cyclopentadienyl ligands of the ferrocene junction. The target structures were obtained through a modular strategy that enables the assembly of varying ring sizes from a common precursor. In particular, macrocycles were either formed by an ether formation reaction or by ring‐closing metathesis reactions. The macrocycles were obtained in reasonable isolated yields, which allowed their thorough characterization by one‐ and two‐dimensional NMR spectroscopy experiments, and the identity of one macrocycle was corroborated by single‐crystal X‐ray diffraction.
Copper(II)‐Catalyzed C–S Cross‐Coupling with Thiazolidine‐2‐thiones and Boronic Acids: Synthesis of Azole Sulfides
Authors: Shanmugapriya Jayabalan , Rajaguru Kandasamy , Muthusubramanian Shanmugam , Bhuvanesh Nattamai 
Published: April 2016

AbstractThe copper(II)‐catalyzed C–S cross coupling of thiazolidine‐2‐thiones with organoboronic acids towards the synthesis of azole sulfides was investigated. This mild and base‐free protocol has the advantages of short reaction times and excellent yields with no need for an ancillary ligand.
Metal‐Free Direct Dehydroxytri­fluoromethylthiolation of Alcohols via the Umpolung Reactivity of Trifluoromethanesulfenamides
Authors: Glenadel Quentin , Tlili Anis , Billard Thierry 
Published: April 2016

AbstractA direct dehydroxytrifluoromethylthiolation of alcohols with trifluoromethanesulfenamide has been described. This method, based on the original umpolung reactivity of trifluoromethanesulfenamides, proposes a direct “OH‐SCF3 exchange” under mild and, more especially, metal‐free conditions.
Zirconocenes vs. Alanes: a Crucial Choice of the Allyl Source for Highly Diastereoselective Allylzincation of Nonracemic Chiral Imines
Authors: Coffinet Michael , Jaroschik Florian , Vasse Jean‐Luc 
Published: April 2016

AbstractAn efficient in‐situ generation of allylzinc compounds from allylzirconocenes applied to the allylmetallation of phenylglycinol‐derived imines is described. The key advantage of the method lies in the concomitant formation of a zirconocene during the Zr–Zn transmetallation step, which appears to be beneficial for the stereoselectivity of the reaction. In the specific case of coupling of imines with racemic chiral allylzinc compounds, this method provides highly diastereoselective access to valuable enantiomerically enriched amines with high synthetic potential.
A Novel Impedimetric Biosensor for Detection of Lead (II) with Low‐cost Interdigitated Electrodes Made on PCB
Authors: Cui Haixia , Xiong Xingliang , Gao Bin , Chen Zhen , Luo Yiting , He Fengjie , Deng Shixiong , Chen Longcong 
Published: April 2016

AbstractA novel, low‐cost, label‐free impedance biosensor based on gold interdigitated electrodes (GIE) was developed for detection of lead. This sensor was developed by immobilizing GR‐5 DNAzymes onto the GIE surface through Au‐S bonding. In the presence of lead, the substrate strand was cleaved into two parts at the RNA site (rA) and caused changes in the interfacial properties of the GIE, resulting in a corresponding decrease in the impedance magnitude. Thus, by measuring the decrease, the concentration of lead ion can be determined. And coupled the GIE with GR‐5 DNAzyme recognition, our proposed lead biosensor exhibited a high sensitivity with a detection limit of 6.61 nM, which is much lower than the 72 nM defined as the maximum contamination level (MCL) of lead ions in drinking water by The United States Environmental Protection Agency (EPA), at the same time, with a linear range from 10–100 nM and a prominent selectivity against other heavy metal ions. What's more, different from the traditional way, the GIE are made on printed circuit board (PCB), this makes the biosensor has the advantages of simplicity, low cost and easy mass production, and it can easily be widely used.
MEKC‐LIF method for analysis of amino acids after on‐capillary derivatization by transverse diffusion of laminar flow profiles mixing of reactants for assessing developmental capacity of human embryos after in vitro fertilization
Authors: Celá Andrea , Mádr Aleš , Dědová Tereza , Pelcová Marta , Ješeta Michal , Žáková Jana , Crha Igor , Glatz Zdeněk 
Published: April 2016

Evaluating the physiological state of an organism is of clinical importance. In assisted reproduction, knowledge of the embryo's physiology is crucial for selecting the embryo with the highest developmental capacity to ensure high pregnancy rates. Amino acids (AAs) are involved in many biochemical processes during embryo development, which means that the determination of AA fluctuations in the embryo's surroundings can determine the embryo's physiological state. Since current embryo selection methods are mainly based on visual assessment, which lacks proper accuracy, a novel method for the analysis of AAs in the embryo's surroundings was developed. AAs were analyzed by means of MEKC‐LIF after on‐capillary derivatization by naphthalene‐2,3‐dicarboxaldehyde. The reactants were injected under the three zone arrangement and mixed using the transverse diffusion of laminar flow profiles methodology. The resulting derivatives of all the standard AAs were baseline resolved in the BGE comprised of 35 mM sodium tetraborate, 55 mM SDS, 2.7 M urea, 1 mM BIS‐TRIS propane, and 23 mM NaOH within 50 min. The method was applied on an analysis of spent culture media used in assisted reproduction to culture embryos after in vitro fertilization.
Preparation of phosphorylcholine‐based hydrophilic monolithic column and application for analysis of drug‐related impurities with capillary electrochromatography
Authors: Qiu Danye , Li Feng , Zhang Mingyu , Kang Jingwu 
Published: April 2016

A hydrophilic monolithic CEC column was prepared by thermal copolymerization of zwitterionic monomer 2‐methacryloyloxyethyl phosphorylcholine (MPC), pentaerythritol triacrylate (PETA), either methacrylatoethyl trimethyl ammonium chloride (META) or sodium 2‐methylpropene‐1‐sulfonate (MPS) in a polar binary porogen consisting of methanol and THF. A typical hydrophilic interaction LC retention mechanism was observed for low‐molecular weight polar compounds including amides, nucleotides, and nucleosides in the separation mode of hydrophilic interaction CEC, when high content of ACN (>60%) was used as the mobile phase. The effect of the electrostatic interaction between the analytes and the stationary phase was found to be negligible. The poly(MPC‐co‐PETA‐co‐META or MPS) monolithic columns have an average column efficiency of 40 000 plates/m and displayed with a satisfactory repeatability in terms of migration time and peak areas. Finally, the column was successfully applied to determine the impurities of a positively charged drug pramipexole which are often separated by ion pair RP chromatography due to their high hydrophilicity. All four components can be baseline separated within 5 min with BGE consisting of ACN/20 mM ammonium formate buffer (pH 3.0; 80/20).
Thermoelectric Properties of Indium(III)‐Doped Copper Antimony Selenide Thin Films Deposited Using a Microwave‐Assisted Technique
Authors: Ghanwat Vishvanath B. , Mali Sawanta S. , Bagade Chaitali S. , Mane Rahul M. , Hong Chang Kook , Bhosale P. N. 
Published: April 2016

AbstractThe improvement of the thermoelectric performance of semiconducting chalcogenides is an important task. The principal challenge in this field is to tailor the thermoelectric properties, such as electrical conductivity, Seebeck coefficient, and thermal conductivity, to improve the figure of merit (ZT). Herein, we present an improvement in the thermoelectric properties of InIII‐doped p‐type Cu3SbSe4 thin films deposited by using a microwave‐assisted technique. The deposited thin films were characterized for their optical, structural, morphological, compositional, and electrical transport properties to show the applicability of the materials in thermoelectric energy conversion. The improvement in ZT is achieved with InIII doping because of the enhancement in the charge carrier density of Cu3SbSe4 thin films. A maximum ZT of 0.183 was achieved for Cu3(Sb0.94In0.06)Se4 at 300 K. Our results show that this deposition strategy and doping process can provide an effective solution to fabricate Cu3SbSe4‐based materials for thermoelectric applications.
A regularized fiber element model for reinforced concrete shear walls
Authors: Vásquez Jorge A. , de la Llera Juan C. , Hube Matías A. 
Published: April 2016

SummaryReinforced concrete shear walls are used because they provide high lateral stiffness and resistance to extreme seismic loads. However, with the increase in building height, these walls have become slenderer and hence responsible of carrying larger axial and shear loads. Because 2D/3D finite element inelastic models for walls are still complex and computationally demanding, simplified but accurate and efficient fiber element models are necessary to quickly assess the expected seismic performance of these buildings. A classic fiber element model is modified herein to produce objective results under particular loading conditions of the walls, that is, high axial loads, low axial loads, and nearly constant bending moment. To make it more widely applicable, a shear model based on the modified compression field theory was added to this fiber element. Consequently, this paper shows the formulation of the proposed element and its validation with different experimental results of cyclic tests reported in the literature. It was found that in order to get objective responses in the element, the regularization techniques based on fracture energy had to be modified, and nonlinearities because of buckling and fracture of steel bars, concrete crushing, and strain penetration effects were needed to replicate the experimental cyclic behavior. Thus, even under the assumption of plane sections, which makes the element simple and computationally efficient, the proposed element was able to reproduce the experimental data, and therefore, it can be used to estimate the seismic performance of walls in reinforced concrete buildings. Copyright © 2016 John Wiley & Sons, Ltd.
Anti-anxiety drugs and fish behavior: Establishing the link between internal concentrations of oxazepam and behavioral effects
Authors: Huerta Belinda , Margiotta-Casaluci Luigi , Rodríguez-Mozaz Sara , Scholze Martin , Winter Matthew J. , Barceló Damià , Sumpter John P. 
Published: April 2016

Abstract

Psychoactive drugs are frequently detected in the aquatic environment. The evolutionary conservation of the molecular targets of these drugs in fish suggests that they may elicit mode of action–mediated effects in fish as they do in humans, and the key open question is at what exposure concentrations these effects might occur. In the present study, the authors investigated the uptake and tissue distribution of the benzodiazepine oxazepam in the fathead minnow (Pimephales promelas) after 28 d of waterborne exposure to 0.8 μg L−1, 4.7 μg L−1, and 30.6 μg L−1. Successively, they explored the relationship between the internal concentrations of oxazepam and the effects on fish exploratory behavior quantified by performing 2 types of behavioral tests, the novel tank diving test and the shelter-seeking test. The highest internal concentrations of oxazepam were found in brain, followed by plasma and liver, whereas muscle presented the lowest values. Average concentrations measured in the plasma of fish from the 3 exposure groups were, respectively, 8.7 ± 5.7 μg L−1, 30.3 ± 16.1 μg L−1, and 98.8 ± 72.9 μg L−1. Significant correlations between plasma and tissue concentrations of oxazepam were found in all 3 groups. Exposure of fish to 30.6 µg L−1 in water produced plasma concentrations within or just below the human therapeutic plasma concentration (HTPC) range in many individuals. Statistically significant behavioral effects in the novel tank diving test were observed in fish exposed to 4.7 μg L−1. In this group, plasma concentrations of oxazepam were approximately one-third of the lowest HTPC value. No significant effects were observed in fish exposed to the lowest and highest concentrations. The significance of these results is discussed in the context of the species-specific behavior of fathead minnow and existing knowledge of oxazepam pharmacology. Environ Toxicol Chem 2016;35:2782–2790. © 2016 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Field assessment of the impacts of Deepwater Horizon oiling on coastal marsh vegetation of Mississippi and Alabama
Authors: Willis Jonathan M. , Hester Mark W. , Rouhani Shahrokh , Steinhoff Marla A. , Baker Mary C. 
Published: April 2016

Abstract

The Deepwater Horizon incident, which occurred in April 2010, resulted in significant oiling of coastal habitats throughout the northern Gulf of Mexico. Although the most substantial oiling of coastal salt marshes occurred in Louisiana, oiling of salt marshes in Mississippi and Alabama was documented as well. A field study conducted in Mississippi and Alabama salt marshes as a component of the Deepwater Horizon Natural Resource Damage Assessment determined that &gt;10% vertical oiling of plant tissues reduced live vegetation cover and aboveground biomass (live standing crop) relative to reference sites in this region through fall 2012. This reduction of live vegetation cover and aboveground biomass appears to have largely resulted from diminished health and vigor of Juncus roemerianus, a key salt marsh species in Mississippi and Alabama. Fewer significant reductions in live vegetation cover and aboveground biomass were detected by the fall 2013 sampling, suggesting that vegetation in oiled salt marshes in this region may have begun to recover. This is corroborated by low levels of Deepwater Horizon oil contamination in these salt marsh soils. However, these findings should be interpreted in the context of the restricted sampling intensity of the present study. Environ Toxicol Chem 2016;35:2791–2797. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.
Chemical and biochemical characterization and in vivo safety evaluation of pharmaceuticals in drinking water
Authors: de Jesus Gaffney Vanessa , Mota-Filipe Helder , Pinto Rui Amaro , Thiemermann Chris , Loureiro Marta , Cardoso Vitor Vale , Benoliel Maria João , Almeida Cristina M.M. 
Published: April 2016

Abstract

The water constituents that are currently subject to legal control are only a small fraction of the vast number of chemical substances and microorganisms that may occur in both the environment and water resources. The main objective of the present study was to study the health impact resulting from exposure to a mixture of pharmaceuticals that have been detected in tap water at low doses. Analyses of atenolol, caffeine, erythromycin, carbamazepine, and their metabolites in blood, urine, feces, fat tissue, liver, and kidney after exposure to a mixture of these pharmaceuticals in treated drinking water were performed. The effects of this exposure were assessed in rats by measuring biochemical markers of organ injury or dysfunction. Simultaneously, the selected pharmaceuticals were also quantified in both physiological fluids and organ homogenates by liquid chromatography–tandem mass spectrometry (performed in multiple reaction monitoring mode and full scan mode). Following exposure of rats to a concentration of a pharmaceutical which was 10 times higher than the concentration known to be present in tap water, trace levels of some pharmaceuticals and their metabolites were detected in biological samples. This exposure did, however, not lead to significant organ injury or dysfunction. Thus, the authors report an experimental model that can be used to characterize the safety profile of pharmaceuticals in treated drinking water using a multiorgan toxicity approach. Environ Toxicol Chem 2016;35:2674–2682. © 2016 SETAC
Validation of a new standardized test method for the freshwater amphipod Hyalella azteca: Determining the chronic effects of silver in sediment
Authors: Taylor Lisa N. , Novak Lesley , Rendas Martina , Antunes Paula M.C. , Scroggins Rick P. 
Published: April 2016

Abstract

Environment Canada has developed a new 42-d sediment toxicity test method that includes a reproduction test endpoint with the freshwater amphipod Hyalella azteca. Because of concerns that existing standard methodologies, whereby adults are transferred to a water-only exposure before release of their first brood at day 28, will lead to internal contaminant depuration and loss of sensitivity, the Environment Canada methodology conducts the entire exposure in sediment. To demonstrate applicability of the method for assessing the toxicity of chemical-spiked sediment, H. azteca were exposed for 42 d to sediment amended with silver nitrate (AgNO3). Mortality was significantly higher at the highest sediment concentration of Ag (2088 mg/kg dry wt); however, there was no significant reduction in biomass or reproduction as a result of Ag exposure despite significant bioaccumulation. Based on Ag measurements and speciation modeling, the principle route of Ag exposure was likely through the ingestion of complexed colloidal or particulate Ag. The techniques used to recover young amphipods from sediment were critical, and although this effort can be labor intensive (20–45 min/replicate), the technicians demonstrated 91% recovery in blind trials. For the first time, Environment Canada will require laboratories to report their recovery proficiency for the 42-d test—without this information, data will not be accepted. Overall, the reproduction test will be more applicable when only a few chemical concentrations need to be evaluated in laboratory-amended sediments or for field-collected contaminated site assessments (i.e., contaminated site vs reference site comparisons). Environ Toxicol Chem 2016;35:2430–2438. © 2016 SETAC
The Prediction of Labor Force Status: Implications From International Adult Skill Assessments
Authors: Li Tongyun , von Davier Matthias , Hancock Gregory R. , Kirsch Irwin S. 
Published: April 2016

AbstractThis report investigates the prediction of labor force status using observed variables, such as gender, age, and immigrant status, and more importantly, measured skill variables, including literacy proficiency and a categorical rating of educational attainment based on the 1994 International Adult Literacy Survey (IALS), the 2003 Adult Literacy and Life Skills Survey (ALL), and the 2011 Programme for the International Assessment of Adult Competencies (PIAAC) projects. We explored the regression relations in the past two decades for six trend countries and subnational regions that provide data for all assessments: the United States, Norway, the Netherlands, Italy, Canada's English‐speaking region, and Canada's French‐speaking region. Probit regression models with latent predictors were used in this cross‐sectional study to investigate how those variables are structurally related to labor market outcomes. Results show the importance of literacy proficiency and education in determining individuals' labor force status across countries/regions, but with key differences among these countries/regions.
An improved Rhie–Chow interpolation scheme for the smoothed‐interface immersed boundary method
Authors: Yi Wei , Corbett Daniel , Yuan Xue‐Feng 
Published: April 2016

SummaryRhie–Chow interpolation is a commonly used method in CFD calculations on a co‐located mesh in order to suppress non‐physical pressure oscillations arising from chequerboard effects. A fully parallelized smoothed‐interface immersed boundary method on a co‐located grid is described in this paper. We discuss the necessity of modifications to the original Rhie–Chow interpolation in order to deal with a locally refined mesh. Numerical simulation with the modified scheme of Choi shows that numerical dissipation due to Rhie–Chow interpolation introduces significant errors at the immersed boundary. To address this issue, we develop an improved Rhie–Chow interpolation scheme that is shown to increase the accuracy in resolving the flow near the immersed boundary. We compare our improved scheme with the modified scheme of Choi by parallel simulations of benchmark flows: (i) flow past a stationary cylinder; (ii) flow past an oscillating cylinder; and (iii) flow past a stationary elliptical cylinder, where Reynolds numbers are tested in the range 10–200. Our improved scheme is significantly more accurate and compares favourably with a staggered grid algorithm. We also develop a scheme to compute the boundary force for the direct‐forcing immersed boundary method efficiently. Copyright © 2016 John Wiley & Sons, Ltd.
Evaluation of a Two‐Stage Approach in Trans‐Ethnic Meta‐Analysis in Genome‐Wide Association Studies
Authors: Hong Jaeyoung , Lunetta Kathryn L. , Cupples L. Adrienne , Dupuis Josée , Liu Ching‐Ti 
Published: April 2016

ABSTRACTMeta‐analysis of genome‐wide association studies (GWAS) has achieved great success in detecting loci underlying human diseases. Incorporating GWAS results from diverse ethnic populations for meta‐analysis, however, remains challenging because of the possible heterogeneity across studies. Conventional fixed‐effects (FE) or random‐effects (RE) methods may not be most suitable to aggregate multiethnic GWAS results because of violation of the homogeneous effect assumption across studies (FE) or low power to detect signals (RE). Three recently proposed methods, modified RE (RE‐HE) model, binary‐effects (BE) model and a Bayesian approach (Meta‐analysis of Transethnic Association [MANTRA]), show increased power over FE and RE methods while incorporating heterogeneity of effects when meta‐analyzing trans‐ethnic GWAS results. We propose a two‐stage approach to account for heterogeneity in trans‐ethnic meta‐analysis in which we clustered studies with cohort‐specific ancestry information prior to meta‐analysis. We compare this to a no‐prior‐clustering (crude) approach, evaluating type I error and power of these two strategies, in an extensive simulation study to investigate whether the two‐stage approach offers any improvements over the crude approach. We find that the two‐stage approach and the crude approach for all five methods (FE, RE, RE‐HE, BE, MANTRA) provide well‐controlled type I error. However, the two‐stage approach shows increased power for BE and RE‐HE, and similar power for MANTRA and FE compared to their corresponding crude approach, especially when there is heterogeneity across the multiethnic GWAS results. These results suggest that prior clustering in the two‐stage approach can be an effective and efficient intermediate step in meta‐analysis to account for the multiethnic heterogeneity.