bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Future of Polar Organometallic Chemistry Written in Bio‐Based Solvents and Water
Authors: García‐Álvarez Joaquín , Hevia Eva , Capriati Vito 
Published: June 2018

AbstractThere is a strong imperative to reduce the release of volatile organic compounds (VOCs) into the environment, and many efforts are currently being made to replace conventional hazardous VOCs in favour of safe, green and bio‐renewable reaction media that are not based on crude petroleum. Recent ground‐breaking studies from a few laboratories worldwide have shown that both Grignard and (functionalised) organolithium reagents, traditionally handled under strict exclusion of air and humidity and in anhydrous VOCs, can smoothly promote both nucleophilic additions to unsaturated substrates and nucleophilic substitutions in water and other bio‐based solvents (glycerol, deep eutectic solvents), competitively with protonolysis, at room temperature and under air. The chemistry of polar organometallics in the above protic media is a complex phenomenon influenced by several factors, and understanding its foundational character is stimulating in the perspective of the development of a sustainable organometallic chemistry.
Enantiomeric separation of Novel Psychoactive Substances by capillary electrophoresis using (+)‐18‐crown‐6‐tetracarboxylic acid as chiral selector
Authors: Hägele Johannes S. , Schmid Martin G. 
Published: June 2018

AbstractIn the recent years, hundreds of Novel Psychoactive Substances (NPS) have entered both the European and the global drug market. These drugs, which are mainly used for recreational matters, have caused serious social problems. Every year, the spectrum of these misused drugs is enlarged by new derivatives, which are produced by modifications of basic structures of already well‐known substances. Additionally, a lot of them possess a stereogenic center which leads to 2 enantiomeric forms. The fact that the pharmacological effects and potencies of the enantiomers of these chiral NPS may differ can be assumed from a broad spectrum of active pharmaceutical ingredients. For this reason, analytical method development regarding enantiomeric separation for these classes of substances is of great pharmaceutical and medical interest. The aim of this work was to create an easy‐to‐prepare chiral capillary electrophoresis method for the enantioseparation of NPS which contains a primary amino group by means of (+)‐18‐crown‐6‐tetracarboxylic acid as chiral selector. Novel Psychoactive Substances were purchased at various Internet stores or represent samples seized by Austrian police. The effects of selector concentration, the electrolyte composition, and the addition of organic modifiers to the background electrolyte on enantioseparation were investigated. Under optimized conditions, the use of 20‐mM (+)‐18‐crown‐6‐tetracarboxylic acid, 10‐mM Tris, and 30‐mM citric acid buffer at pH 2.10 turned out to be effective. Fifteen of 24 tested NPS were resolved in their enantiomers within 15 minutes. It was found that all NPS were traded as racemic mixtures.
Activation and deactivation scenarios in a plasma‐synthesized Co/C catalyst for Fischer‐Tropsch synthesis
Authors: Aluha James , Abatzoglou Nicolas 
Published: June 2018

ABSTRACTA carbon‐supported cobalt nano‐catalyst (Co/C) synthesized through plasma was tested for Fischer‐Tropsch activity. Catalyst deactivation and activation protocols studied included in situ sample pre‐treatment at 673 K in gas flowing at the rate of 250 cm3 · min−1 in: (a) H2 only, (b) CO only, and (c) CO followed by H2, with each cycle lasting 24 h. The so‐treated catalyst samples were then tested for FTS activity for over 50 h of time‐on‐stream (TOS), at 2.2 MPa pressure and 493 or 518 K temperature in a 3‐phase continuously‐stirred tank slurry reactor (3‐φ‐CSTSR) using squalane (C30H62) as the carrier liquid phase. The feed gas composition of molar H2:CO = 1.7 comprising 50 % H2, 30 % CO, and 10 % CO2 balanced in Ar for mass balance determination, flowing at a gas hourly space velocity (GHSV) of 3360 cm3 · h−1 · g−1 of catalyst. Fresh catalysts and those reduced by CO‐only were completely inactive at 493 K and initial inactivity was attributed to the excessive C matrix formed around the metal nanoparticles during catalyst synthesis. The sample that was reduced by H2 only was the most active, although it showed the fastest declining activity due to cumulative high H2O vapour pressure in the FTS reactor, while the sample pre‐treated in both CO and H2 demonstrated a higher degree of stability with TOS.
1,2,3‐Triazolium‐Based Cationic Amphipathic Peptoid Oligomers Mimicking Antimicrobial Helical Peptides
Authors: Shyam Radhe , Charbonnel Nicolas , Job Aurélie , Blavignac Christelle , Forestier Christiane , Taillefumier Claude , Faure Sophie 
Published: June 2018

AbstractAmphipathic cationic peptoids (N‐substituted glycine oligomers) represent a promising class of antimicrobial peptide mimics. The aim of this study is to explore the potential of the triazolium group as a cationic moiety and helix inducer to develop potent antimicrobial helical peptoids. Herein we report the first solid‐phase synthesis of peptoid oligomers incorporating 1,2,3‐triazolium‐type side chains and their evaluation against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus. Several triazolium‐based oligomers, even of short length, selectively kill bacteria over mammalian cells. SEM visualization of S. aureus cells treated with a dodecamer and a hexamer reveals severe cell membrane damage and suggests that the longer oligomer acts by pore formation.
In vitro simulation of erosive challenges to human enamel using a novel artificial mouth
Authors: Qutieshat Abubaker S. , Mason Andrew Graham , Chadwick Richard Graham 
Published: June 2018

AbstractThis in vitro work reports upon the design, build and operation of an artificial environment (Saltus) that sought to simulate the process of in vivo dental erosion upon human enamel. A novel testing environment, housed 8 erosion testing substrate specimens, that on separate occasions were subject to 4 different experimental diets, of increasing erosive challenge, simulating the consumption of an acidic beverage. Each set of specimens was subjected to one of the experimental diets only. These were liquid only and administered the test beverage over a standardized range of volumes and durations. Flow of both artificial unstimulated and stimulated saliva was maintained throughout and the effects upon the substrates were measured by profilometry, surface microhardness determination and chemical analysis of the saliva and beverage mixture for traces of Calcium and Phosphate ions. The overall trend of surface hardness reduction, depth of surface loss and ion loss across the diets increased in proportion to the severity of insult. Accepting the limitations of this study Saltus appeared to perform well as an environment in which to simulate and assess dental erosion using parameters defined by previous in vivo observations of human drinking behaviour. The authors however acknowledge that in vitro testing can never replicate fully the in vivo situation.
Facile Modification of Titania with Nickel Sulfide and Sulfate Species for the Photoreformation of Cellulose into Hydrogen
Authors: Hao Hongchang , Zhang Ling , Wang Wenzhong , Zeng Shuwen 
Published: June 2018

AbstractPhotocatalytic cellulose reformation is regarded as a potential and affordable route for sustainable H2 evolution. However, direct photoreformation still suffers from challenges such as the limited solubility of cellulose and the dependence on the catalytic activity of noble metals. Herein, we report a new photoreformation of cellulose into H2 over TiO2 that is modified with nickel sulfide (NixSy) and chemisorbed sulfate species (SO42−) by a one‐pot approach. A significant elevation in the photocatalytic hydrogen evolution rate is achieved with a maximal value of 3.02 mmol g−1 h−1 during the first 3 h, which is almost 76‐fold higher than that of P25 and comparable to that of Pt‐P25. Aided by systematic investigation, it is proposed that nickel sulfide and sulfate modification contribute synergistically to the remarkably increased efficiency of biomass transformation. Specifically, NixSy acts as a cocatalyst for photocatalytic H2 production, and we infer that SO42− ions promote cellulose hydrolysis and the consequent accessibility of the biomass to catalysts. Further, the accumulated formate intermediates have a poisoning effect on the catalysts, the desorption of which can be controlled by tuning the aqueous alkalinity. Overall, our strategy for the modification of TiO2 with SO42− and NixSy provides a new perspective for the concurrent acceleration of cellulose hydrolysis and increase of the number of hydrogen evolution sites for the efficient photocatalytic reformation of cellulose into H2.
Solution‐Processed Air‐Stable Copper Bismuth Iodide for Photovoltaics
Authors: Hu Zhaosheng , Wang Zhen , Kapil Gaurav , Ma Tingli , Iikubo Satoshi , Minemoto Takashi , Yoshino Kenji , Toyoda Taro , Shen Qing , Hayase Shuzi 
Published: June 2018

AbstractBismuth‐based solar cells have been under intensive interest as an efficient non‐toxic absorber in photovoltaics. Within this new family of semiconductors, we herein report a new, long‐term stable copper bismuth iodide (CuBiI4). A solutionprocessed method under air atmosphere is used to prepare the material. The adopted HI‐assisted dimethylacetamide (DMA) co‐solvent can completely dissolve CuI and BiI3 powders with high concentration compared with other organic solvents. Moreover, the high vapor pressure of tributyl phosphate, selected for the solvent vapor annealing (SVA), enables complete low‐temperature (≤70 °C) film preparation, resulting in a stable, uniform, dense CuBiI4 film. The average grain size increases with the precursor concentration, greatly improving the photoluminescence lifetime and hall mobility; a carrier lifetime of 3.03 ns as well as an appreciable hall mobility of 110 cm2 V−1s−1 were obtained. XRD illustrates that the crystal structure is cubic (space group Fd3m) and favored in the [1 1 1] direction. Moreover, the photovoltaic performance of CuBiI4 was also investigated. A wide bandgap (2.67 eV) solar cell with 0.82 % power conversion efficiency is presented, which exhibits excellent long‐term stability over 1008 h under ambient conditions. This air‐stable material may give an application in future tandem solar cells as a stable short‐wavelength light absorber.
A high‐speed RSD‐based flexible ECC processor for arbitrary curves over general prime field
Authors: Shah Yasir Ali , Javeed Khalid , Azmat Shoaib , Wang Xiaojun 
Published: June 2018

SummaryThis workpresents a novel high‐speed redundant‐signed‐digit (RSD)‐based elliptic curve cryptographic (ECC) processor for arbitrary curves over a general prime field. The proposed ECC processor works for any value of the prime number and curve parameters. It is based on a new high speed Montgomery multiplier architecture which uses different parallel computation techniques at both circuit level and architectural level. At the circuit level, RSD and carry save techniques are adopted while pre‐computation logic is incorporated at the architectural level. As a result of these optimization strategies, the proposed Montgomery multiplier offers a significant reduction in computation time over the state‐of‐the‐art. At the system level, to further enhance the overall performance of the proposed ECC processor, Montgomery ladder algorithm with (X,Y)‐only common Z coordinate (co‐Z) arithmetic is adopted. The proposed ECC processor is synthesized and implemented on different Xilinx Virtex (V) FPGA families for field sizes of 256 to 521 bits. On V‐6 platform, it computes a single 256 to 521 bits scalar point multiplication operation in 0.65 to 2.6 ms which is up to 9 times speed‐up over the state‐of‐the‐art.
Analysis of mismatch impact on image rejection ratio for passive polyphase filters
Authors: Martínez‐Pérez A.D. , Aznar F. , Royo G. , Sánchez‐Azqueta C. , Celma S. 
Published: June 2018

SummaryPassive polyphase filters (PPFs) are useful symmetric RC networks for processing analog quadrature signals. Passive polyphase filters are also used to implement differential‐quadrature or quadrature‐differential converters. The quality of these quadrature signals is essential to achieve good performance in modern communication systems. However, mismatch effects can produce notable degradation in the PPF frequency response, and this results in an important reduction in quadrature signal quality, being amplitude balance and phase offset notably affected. Both these errors could be summarized and evaluated together considering image rejection ratio as a figure of merit. This work deepens in the analysis of mismatch impact on PPF, studying image rejection ratio degradation for 2 PPF types, and a systematic method is proposed to obtain the worst case of mismatch in PPFs with any number of stages. It has been validated in a 65‐nm CMOS technology.
A constraint optimization of low‐delay and low‐operation driven FIR digital filters for big data signal processing
Authors: Hirakawa Tomohiro , Nakamoto Masayoshi 
Published: June 2018

AbstractIn big data signal processing system, low‐delay and low‐operation driven digital filters are required for large amounts of data processing. We introduce a design method for low‐delay FIR (finite impulse response) filters with semi‐sparse coefficients. The semi‐sparse coefficients stand for to have some 0 ± 1 values with real values. The semi‐sparse coefficients lead to reduction of number of multipliers. We show the design problem of the filters are formulated in a constraint optimization problem. Also, we propose a design algorithm to solve the design problem. Using the filters, the number of multipliers can be reduced. Finally, we present examples to demonstrate the effectiveness of the proposed method.
Soil homogenization and microedges: perspectives on soil‐based drivers of plant diversity and ecosystem processes
Authors: Stover Holly J. , Henry Hugh A. L. 
Published: June 2018

AbstractDisturbance caused by agriculture and resource extraction has resulted in widespread homogenization of soils at the local (within‐site) scale. Here, we describe how experimental manipulation of heterogeneity at the local scale has had inconsistent effects on plant species diversity. Moreover, we discuss how soil homogenization per se typically has not been accounted for in the study of heterogeneity–diversity relationships, and how disturbance, often viewed as an artifact in soil heterogeneity experiments, can be a key driver of soil homogenization. We propose a conceptual model for describing the relationship between plant size, patch size, and diversity, and we discuss how factors such as disturbance, productivity, and competition among species either should be controlled or accounted for in soil heterogeneity–plant diversity experiments. Finally, we consider the concept of soil patch microedges, which may provide unique microsites for increased plant diversity, and how these biogeochemical and hydrological interfaces could potentially drive ecosystem processes in a manner unique from the adjacent patches. Overall, this synthesis integrates perspectives on the functional links between plant‐driven processes, and soil patterns and processes.
Design of a coil geometry for generating magnetic field to evaluate biological effects at 85 kHz
Authors: Matsubara Kazuki , Wada Keiji , Suzuki Yukihisa 
Published: June 2018

AbstractIn recent years, the use of induction‐heating systems has increased and wireless power transmission (WPT) systems have been discussed. These applications are installed close to a human body. Therefore, it is important to discuss the effects of alternating magnetic fields and to evaluate electromagnetic interference. This paper discusses the design procedure of a magnetic field generator to evaluate the electromagnetic interference at 85 kHz that is being studied in WPT systems for EV and HEV. The magnetic field generator presented in this paper consists of a single‐phase inverter circuit that uses SiC‐MOSFETs and an air–core inductor that is used as the coil for generating a magnetic field. In particular, this paper shows that the coil used for generating magnetic field needs to reduce the winding voltage to generate higher magnetic flux. In addition, this paper presents the design procedure of the proposed coil structure that can satisfy some limited conditions. The experimental results of the proposed system rated at 82 kHz and 100 A are presented.
Online fully automated SPE‐HPLC‐MS/MS determination of ceftiofur in bovine milk samples employing a silica‐anchored ionic liquid as sorbent
Authors: Ferreira Débora Cecatto , de Toffoli Ana Lúcia , Maciel Edvaldo Vasconcelos Soares , Lanças Fernando Mauro 
Published: June 2018

AbstractSolid‐phase extraction coupled online with high performance liquid chromatography and tandem mass spectrometry was successfully applied to determine low concentrations of ceftiofur antibiotic in bovine milk samples. A silica‐anchored ionic liquid was applied as sorbent material to be used as extraction phase in the proposed online system. The material was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. In order to improve the system reproducibility, the following experimental parameters were optimized: organic solvent percentage, time and sample loading flow rate. Subsequently, the method was validated presenting satisfactory results as adequate selectivity, good linearity and correlation coefficient higher than 0.98. The limit of detection and quantification were 0.1 and 0.7 μg/L, respectively. The precision of the methodology was evaluated as repeatability and intermediate precision, with relative standard deviation values lower than 15%. The accuracy of the method ranged from 72.8 to 137% and the minimum and maximum recovery values were 73.4 and 111.3%, respectively. After the validation, seven milk samples were analyzed and although ceftiofur was not detected in any of them the method was demonstrated to be efficient when applied to the analysis of milk samples fortified with the pollutant of interest.
Elevated aeolian sediment transport on the Colorado Plateau, USA: The role of grazing, vehicle disturbance, and increasing aridity
Authors: Nauman Travis W. , Duniway Michael C. , Webb Nicholas P. , Belnap Jayne 
Published: June 2018

AbstractDryland wind transport of sediment can accelerate soil erosion, degrade air quality, mobilize dunes, decrease water supply, and damage infrastructure. We measured aeolian sediment horizontal mass flux (q) at 100 cm height using passive aspirated sediment traps to better understand q variability on the Colorado Plateau. Measured q ‘hot spots’ rival the highest ever recorded including 7,460 g m−2 day−1 in an off‐highway vehicle (OHV) area, but were more commonly 50‐2,000 g m−2 day−1. Overall mean q on rangeland sites was 5.14 g m−2 day−1, considerably lower than areas with concentrated livestock use (9‐19 g m−2 day−1), OHV use (414 g m−2 day−1), and downwind of unpaved roads (13.14 g m−2 day−1), but were higher than areas with minimal soil disturbance (1.60 g m−2 day−1). Rangeland q increased with increasing annual temperature, increased winds, and decreasing precipitation. Spatial modeling suggests that ~92‐93% of regional q occurs in rangelands versus ~7‐8% along unpaved roads. Four of the five largest road q values (n=33) measured were along roads used primarily for oil or gas wells. Our findings indicate that predicted future mega‐droughts will increase q disproportionately in disturbed rangelands, and potentially further compromise air quality, hydrologic cycles, and other ecosystem services. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
Acute toxicity of sodium chloride and potassium chloride to a unionid mussel (Lampsilis siliquoidea) in water exposures
Authors: Wang Ning , Ivey Christopher D. , Dorman Rebecca A. , Ingersoll Christopher G. , Steevens Jeffery , Hammer Edward J. , Bauer Candice R. , Mount David R. 
Published: June 2018

Abstract

Freshwater mussels (order Unionoida) are one of the most imperiled groups of animals in the world. However, many ambient water quality criteria and other environmental guideline values do not include data for freshwater mussels, in part because mussel toxicity test methods are comparatively new and data may not have been available when criteria and guidelines were derived. The objectives of the present study were to evaluate the acute toxicity of sodium chloride (NaCl) and potassium chloride (KCl) to larvae (glochidia) and/or juveniles of a unionid mussel (fatmucket, Lampsilis siliquoidea) and to determine the potential influences of water hardness (50, 100, 200, and 300 mg/L as CaCO3) and other major ions (Ca, K, SO4, or HCO3) on the acute toxicity of NaCl to the mussels. From the KCl test, the 50% effect concentration (EC50) for fatmucket glochidia was 30 mg K/L, similar to or slightly lower than the EC50s for juvenile fatmucket (37–46 mg K/L) tested previously in our laboratory. From the NaCl tests, the EC50s for glochidia increased from 441 to 1597 mg Cl/L and the EC50s for juvenile mussels increased from 911 to 3092 mg Cl/L with increasing water hardness from 50 to 300 mg/L. Increasing K from 0.4 to 1.9 mg/L, SO4 from 13 to 40 mg/L, or HCO3 from 44 to 200 mg/L in the 50 mg/L hardness water did not substantially change the NaCl EC50s for juvenile mussels, whereas increasing Ca from 9.9 to 42 mg/L increased the EC50s by a factor of 2. The overall results indicate that glochidia were equally or more sensitive to NaCl and KCl compared with juvenile mussels and that the increased water hardness ameliorated the acute toxicity of NaCl to glochidia and juveniles. These responses rank fatmucket among the most acutely sensitive freshwater organisms to NaCl and KCl. Environ Toxicol Chem 2018;37:3041–3049. © 2018 SETAC. This article is a US government work and, as such, is in thepublic domain in the United States of America.
The response of cultured meiofaunal and benthic foraminiferal communities to lead exposure: Results from mesocosm experiments
Authors: Frontalini Fabrizio , Semprucci Federica , Di Bella Letizia , Caruso Antonio , Cosentino Claudia , Maccotta Antonella , Scopelliti Giovanna , Sbrocca Claudia , Bucci Carla , Balsamo Maria , Martins Maria Virginia , Armynot du Châtelet Eric , Coccioni Rodolfo 
Published: June 2018

Abstract

Lead (Pb) is regarded as a highly toxic element that poses a serious threat to biota. A mesocosm experiment was performed to assess the influence of Pb on meiofaunal (metazoans within 45–500 μm) and benthic foraminiferal (protozoan) communities. To this end, sediments bearing such communities were incubated in mesocosms, exposed to different levels of Pb in seawater, and monitored for up to 8 wk. Concentrations of Pb &lt;1 ppm in water did not promote a significant increase of this metal in sediments. Relatively high concentrations of Pb seemed to affect meiofaunal and benthic foraminiferal communities by reducing their richness or diversity, and the abundance of the most sensitive taxa. The mesocosm approach can be considered an effective method to document the responses of meiofaunal and benthic foraminiferal communities to various kinds and concentrations of pollutants over time. This approach allows the evaluation of dose–response relationships, validates the outcomes of field studies, and possibly confirms the sediment quality guidelines and thresholds. Environ Toxicol Chem 2018;37:2439–2447. © 2018 SETAC