bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cutting the Green Waste. Structure‐Performance Relationship in Functionalized Carbon Xerogels for Hydrolysis of Cellobiose
Authors: Eblagon Katarzyna Morawa , Malaika Anna , Pereira Manuel Fernando R. , Figueiredo José Luís 
Published: June 2018

AbstractThe hydrolysis of cellulose and hemicelluloses in the presence of solid acid catalysts is of great importance as an entry process for the production of biofuels and chemicals. In this work, the effect of carbon surface chemistry on the catalyst conversion and selectivity in hydrolysis of cellobiose to glucose was studied. Solid catalysts based on carbon xerogels (CXs) containing various functionalities incorporating heteroatoms (S, P, N, O), as confirmed by XPS, TPD, ICP and EA analyses, were successfully prepared. CXs containing 3.4 wt % of phosphorus showed the best catalytic performance, reaching 90 % conversion of cellobiose with 72 % selectivity to glucose, under oxidative atmosphere and in a short reaction time of only 4 h. The presence of phosphonates (−P−C−) was found to increase the selectivity to glucose up to unprecedented 87 %. On the contrary, carbonyls, quinones, pyrydinic, pyrrolic and sulfonic groups were found to promote glucose degradation, leading to a final low yield of this product. Additionally, the increased concentration of oxygen in the reaction atmosphere was shown to significantly weaken the β (1–4)‐glycosidic bond, increasing the final yield of glucose.
Solvent‐free Strategy of Photocarriers Accumulated Site and Separated Path for Porous Hollow Spindle‐Shaped BiPO4
Authors: Xie Jing , Cao Yali , Jia Wei , Zhang Su , Li Yizhao , Hu Jindou , Jia Dianzeng 
Published: June 2018

AbstractPorous, hollow‐structure, inorganic nanomaterials have sparked considerable interest in catalysis and energy conversion systems. However, inorganic nanomaterials with porous hollow structures are generally synthesized under harsh conditions or through complicated procedures, which impedes large‐scale applications. Herein, we describe a novel solid‐state chemical strategy without using templates and surfactants to construct hollow spindle‐shaped BiPO4 (BP). A porous hollow structure containing rich surface oxygen vacancies was achieved by the heat treatment of BP in air at 600 °C (BP‐Air‐600 °C). Benefiting from the synergistic effect, the hollow porous structure increased light‐harvesting efficiency by multiple reflection and the plentiful oxygen vacancies decreased recombination rate of electron‐hole pairs. BP‐Air‐600 °C displays an excellent apparent rate constant for the degradation of methylene blue, which is about 4.7 times higher than that of BP. This study presents a green approach to rational design of porous hollow structured nanomaterials which possess richer surface oxygen defects and excellent photocatalytic performance.
Formation and Separation of Particles fromEmiliania huxleyi
Authors: Chairopoulou Makrina Artemis , Pereyra Clara , Teipel Ulrich 
Published: June 2018

AbstractThree reactor systems forEmiliania huxleyicultivation are reviewed in respect to coccolith production. After cell lysis, the particle size distribution was determined for the system. Fraction changes caused through ultrasonication were characterized by comparing particle size distributions. Insufficient de‐agglomeration and possible re‐agglomeration at longer treatment intervals could be observed. Zeta potential measurements of the treated samples indicated no significant surface modifications. Scanning electron microscopy images showed no structural damages and the particles appeared similar to each other regardless the ultrasound exposure. In addition, settling velocities of the system using different density and viscosity solutions were examined by an analytical centrifuge. Two separation attempts for coccolith recovery are presented.
One‐Step Constructed Electrochemiluminescence Sensor Coupled with Magnetic Enhanced Solid Phase Microextraction to Sensitively Detect Bisphenol‐A
Authors: Hu Yunxia , Wang Sui , Guo Zhiyong , Hu Yufang , Xie Hongzhen 
Published: June 2018

AbstractIn the present study, an electrochemiluminescence quenching approach coupled with magnetic enhanced solid phase microextraction was exploited for the extraction and determination of bisphenol A. The GO‐Fe3O4 nanocomposites as solid phase microextraction sorbent were synthesized for extraction of bisphenol A. It was found that the magnetic field applied using an external magnet can not only achieve rapid separation, but also enhance the extraction efficiency to some extent. The GO−Au nanoparticle (GO‐AuNPs) composites combine the advantages of large specific surface area of graphene oxide and good conductivity of Au nanoparticles. Thus, an electrochemiluminescence sensor was constructed by immobilization of GO‐AuNPs composites on glassy carbon electrodes (GCE). Bisphenol A could quench GO‐AuNPs composites enhanced electrochemiluminescence signal of luminol during the detection stage. Under optimized experimental conditions, the quenched electrochemiluminescence intensity was linearly proportionally to the negative value of the logarithm of the concentration of bisphenol A within the range of 10−8∼10−4 mol/L, with a correlation coefficient r of 0.9920 and a limitation of detection of 4.2×10−9 mol/L. This method can be used to detect bisphenol‐A in real samples, meanwhile its sensitivity was higher based on the enhancing effect of luminol by GO‐AuNPs composites and extraction of target before detection.
The Effect of Media Coverage on the Pricing of Seasoned Equity Offerings
Authors: Pinto‐Gutiérrez Cristian A. 
Published: June 2018

AbstractThis paper examines the role of media coverage and investor attention on the outcomes of seasoned equity offerings (SEOs). I use an archive of Thomson Reuters news articles to proxy for firm visibility and investor attention. I find that the volumes of news articles prior to the offerings are positively associated with the offer price discounts of SEOs. Furthermore, the volumes of news articles are negatively associated with the cumulative abnormal returns three days around the SEOs. I conclude that the costs of equity increase with media coverage prior to SEOs. Overall, the evidence is consistent with the hypothesis that media coverage affects investors' information processing in SEOs. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.
Preliminary study of the surface reactivity of 2D α‐Mo2C crystallites
Authors: Fortin Carole‐Anne , Adnot Alain , McBreen Peter H. 
Published: June 2018

AbstractA preliminary study of the surface reactivity of 2D‐α‐Mo2C crystallites grown on a copper foil was performed using x‐ray photoelectron spectroscopy. Different sample preparation protocols for the as‐received materials were explored in order to remove hydrocarbon surface contamination. Annealing in vacuum and in argon led to the formation of graphitic layers, while annealing in O2 lead to almost the complete disappearance of the Mo signal. Gentle argon ion sputtering proved effective at removing the hydrocarbon contamination to reveal pristine molybdenum carbide. XPS spectra were recorded following the exposure of the prepared sample at 297 K to furfural. The results are commented on in relation to deoxygenation and olefin metathesis surface chemistry.
Effect of Acylation on the Antimicrobial Activity of Temporin B Analogues
Authors: Avitabile Concetta , D'Andrea Luca Domenico , D'Aversa Elisabetta , Milani Roberta , Gambari Roberto , Romanelli Alessandra 
Published: June 2018

AbstractNew peptides derived from the natural antimicrobial temporin B were obtained. The design, antimicrobial activity, and characterization of the secondary structure of peptides in the presence of bacterial cells is described herein. TB_KKG6K (KKLLPIVKNLLKSLL) has been identified as the most active analogue against Gram‐positive and ‐negative bacteria, compared with natural temporin B (LLPIVGNLLKSLL) and TB_KKG6A (KKLLPIVANLLKSLL). Acylation with hydrophobic moieties generally led to reduced activity; however, acylation at the 6‐position of TB_KKG6K led to retained sub‐micromolar activity against Staphylococcus epidermidis.
Efficient Biomass Fuel Cell Powered by Sugar with Photo‐ and Thermal‐Catalysis by Solar Irradiation
Authors: Liu Wei , Gong Yutao , Wu Weibing , Yang Weisheng , Liu Congmin , Deng Yulin , Chao Zi‐sheng 
Published: June 2018

AbstractThe utilization of biomass sugars has received great interesting recently. Herein, we present a highly efficient hybrid solar biomass fuel cell that utilizes thermal‐ and photocatalysis of solar irradiation and converts biomass sugars into electricity with high power output. The fuel cell uses polyoxometalates (POMs) as photocatalyst to decompose sugars and capture their electrons. The reduced POMs have strong visible and near‐infrared light adsorption, which can significantly increase the temperature of the reaction system and largely promotes the thermal oxidation of sugars by the POM. In addition, the reduced POM functions as charge carrier that can release electrons at the anode in the fuel cell to generate electricity. The electron‐transfer rates from glucose to POM under thermal and light‐irradiation conditions were investigated in detail. The power outputs of this solar biomass fuel cell are investigated by using different types of sugars as fuels, with the highest power density reaching 45 mW cm−2.
Panchromatic Sensitization with ZnII Porphyrin‐Based Photosensitizers for Light‐Driven Hydrogen Production
Authors: Ho Po‐Yu , Mark Michael F. , Wang Yi , Yiu Sze‐Chun , Yu Wai‐Hong , Ho Cheuk‐Lam , McCamant David W. , Eisenberg Richard , Huang Shuping 
Published: June 2018

AbstractThree molecular photosensitizers (PSs) with carboxylic acid anchors for attachment to platinized titanium dioxide nanoparticles were studied for light‐driven hydrogen production from a fully aqueous medium with ascorbic acid (AA) as the sacrificial electron donor. Two zinc(II) porphyrin (ZnP)‐based PSs were used to examine the effect of panchromatic sensitization on the photocatalytic H2 generation. A dyad molecular design was used to construct a difluoro boron‐dipyrromethene (bodipy)‐conjugated ZnP PS (ZnP‐dyad), whereas the other one featured an electron‐donating diarylamino moiety (YD2‐o‐C8). To probe the use of the ZnP scaffold in this particular energy conversion process, an organic PS without the ZnP moiety (Bodipy‐dye) was also synthesized for comparison. Ultrafast transient absorption spectroscopy was adopted to map out the energy transfer processes occurring in the dyad and to establish the bodipy‐based antenna effect. In particular, the systems with YD2‐o‐C8 and ZnP‐dyad achieved a remarkable initial activity for the production of H2 with an initial turnover frequency (TOFi) higher than 300 h−1 under white light irradiation. The use of ZnP PSs in dye‐sensitized photocatalysis for the H2 evolution reaction in this study indicated the importance of the panchromatic sensitization capability for the development of light absorbing PSs.
Preface to Special Issue of ChemSusChem on Interfacing Experiment and Theory in the Development of Energy Storage and Devices
Authors: Korth Martin , Balducci Andrea 
Published: June 2018

AbstractThis Editorial discusses the importance of scientists currently working in separate fields—experimental characterization of novel materials and theoretical investigations of electrochemical processes—joining forces to advance the field of energy‐storage materials and devices. Some of these efforts are published in this Special Issue by ChemSusChem.
First identification of a diuretic, hydrochlorothiazide, in hair: Application to a doping case and interpretation of the results
Authors: Gheddar L. , Raul JS. , Kintz P. 
Published: June 2018

AbstractAn athlete contested an adverse analytical finding involving hydrochlorothiazide, and requested our laboratory for testing his hair. As there is no reference in the literature about identification of hydrochlorothiazide in hair, several volunteers were first enrolled (4 after a single 25 mg administration and 10 with daily therapeutic treatment). A specific method was developed by ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS. Hair samples were decontaminated with dichloromethane and 30 mg were incubated in buffer at pH 7.0 for 15 hours at 50°C. Then, 5 mL ethyl acetate was added for extraction. Linearity was observed for hydrochlorothiazide concentrations ranging from 5 to 2000 pg/mg. The limit of quantification was 5 pg/mg. The coefficients of variation (CVs) of repeatability and matrix effect were lower than 20%. Analysis of the 0–2‐cm segment of the 4 volunteers having received a single dose, collected 1 month after administration, was negative at the limit of quantification. The hair of the 10 patients (proximal 2 cm) on daily treatment was positive with concentrations ranging from 12 to 1845 pg/mg, with no correlation between daily dose and concentration. The athlete's hair tested positive for hydrochlorothiazide at 36 pg/mg in the segment corresponding to the period of the urinary control. Since a single exposure to hydrochlorothiazide is not detectable in hair and based on the results of the patients on daily treatment, the concentration found in the athlete has been interpreted as corresponding to repeated exposures, where it was not possible to establish the dosage and the frequency.
Scalability analysis on the smart grid fast automated demand response aggregation Web services for widely distributed building facilities
Authors: Yamada Tomohisa , Suzuki Keita , Ninagawa Chuzo 
Published: June 2018

AbstractIn this paper, we modeled an aggregation communication server of the Fast Automated Demand Response (FastADR) system using an M/M/1 queuing system. Assuming that a very large number of FastADR participating BEMS gateways are widely distributed, scalability of aggregation communication performance was estimated by the M/M/1 transient analysis. Validity of our analysis model was confirmed by realistic wide‐area communication emulation system in the laboratory. Our scalability analysis has shown that at least parallel 25 aggregation systems will be necessary to realize expected communication time of approximately 30 s for an example of FastADR aggregation of 100 MW reduced demand.
A power decoupling control method for an isolated single‐phase AC‐to‐DC converter based on a high‐frequency cycloconverter
Authors: Komeda Shohei , Fujita Hideaki 
Published: June 2018

AbstractThis paper proposes a new power decoupling method for a high‐frequency cycloconverter which converts the single‐phase line‐frequency ac input to the high‐frequency ac output directly. The cycloconverter consists of two half‐bridge inverters, two input filter capacitors, and a series‐resonant circuit. The proposed power decoupling method stores the input power ripple at double the line frequency in the filter capacitors. Therefore, the proposed method achieves a unity power factor in ac input and a constant current amplitude in the high‐frequency output without any additional switching device or energy storage element. This paper theoretically discusses the principle and operating performance of the proposed power decoupling method, and the viability is confirmed by using an experimental isolated ac‐to‐dc converter based on the high‐frequency cycloconverter. As a result, the proposed power decoupling method effectively improved the displacement power factor in the line current to more than 0.99 and reduced the output voltage ripple to 4% without any electrolytic capacitor.
Increased right atrial volume measured with cardiac magnetic resonance is associated with worse clinical outcome in patients with pre‐capillary pulmonary hypertension
Authors: Bredfelt Anna , Rådegran Göran , Hesselstrand Roger , Arheden Håkan , Ostenfeld Ellen 
Published: June 2018

AbstractAimsPre‐capillary pulmonary hypertension (PHpre‐cap) has a poor prognosis, especially when caused by pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc‐PAH). Whether cardiac magnetic resonance (CMR)‐based quantification of atrial volumes in PHpre‐cap is beneficial in risk assessment is unknown. The aims were to investigate if (i) atrial volumes using CMR are associated with death or lung transplantation in PHpre‐cap, (ii) atrial volumes differ among four unmatched major PHpre‐cap subgroups, and (iii) atrial volumes differ between SSc‐PAH and idiopathic/familial PAH (IPAH/FPAH) when matched for pulmonary vascular resistance (PVR).Methods and resultsSeventy‐five PHpre‐cap patients (57 ± 19 years, 53 female, 43 de novo) with CMR and right heart catheterization were retrospectively included. Short‐axis stacks of cine images were analysed, and right and left atrial maximum (RAVmax and LAVmax) and minimum volume (RAVmin and LAVmin) were indexed for body surface area. Increased (mean + 2 SD) and reduced (mean – 2 SD) volumes were predefined from CMR normal values.Transplantation‐free survival was lower in patients with increased RAVmax than in those with normal [hazard ratio (HR) = 2.1, 95% confidence interval (CI) 1.1–4.0] but did not differ between those with reduced LAVmax and normal (HR 2.0, 95% CI 0.8–5.1). RAVmax and RAVmin showed no differences among unmatched or matched groups (P = ns). When matched for PVR, LAVmax, LAVmin, and pulmonary artery wedge pressure were reduced in SSc‐PAH compared with IPAH/FPAH (95% CI 0.3–21.4, 95% CI 0.8–19.6, and 95% CI 2–7, respectively).ConclusionsPatients with PHpre‐cap and increased right atrial volume measured with CMR had worse clinical outcome. When matched for PVR, left atrial volume was lower in SSc‐PAH than in IPAH/FPAH, consistent with left‐sided underfilling, indicating a potential differentiator between the groups.
Total Determination of Estrogenic Phenolic Compounds in River Water Using a Sensor Based on Reduced Graphene Oxide and Molecularly Imprinted Polymer
Authors: Braga Guilherme Bettio , Oliveira Ana Elisa Ferreira , Pereira Arnaldo César 
Published: June 2018

AbstractThe contamination of water and wastewater by emerging pollutants, due to the anthropogenic activities, are an environmental problem that generates several negative impacts. In this range of species, steroids have gaining notoriety because their action of endocrine‐disruption. In this work, they are called estrogenic phenolic compounds (EPCs): estrone (E1), estradiol (E2), ethinyl estradiol (EE2) and estriol (E3), for determination using an electrochemical sensor based on reduced graphene oxide (rGO) and molecularly imprinted polymer (MIP). The analytical method developed, allied with the experimental and operational optimizations, proved to be effective for the total quantification of the EPCs in river water. The method shows sensitivity of 1.12 μA/μmol L−1, detection limit of 26.8 nmol L−1 and linear range of 0.16–15 μmol L−1. The similar electrochemical behavior of the four compounds studied (E1, E2, EE2 and E3) and the efficiency of the modified composite (rGO, MIP) in the fabrication of the sensor resulted in high electrical conductivity and selective adsorptivity, respectively.
Sublethal metabolic responses to contaminant mixture toxicity in Daphnia magna
Authors: Wagner Nicole D. , Simpson André J. , Simpson Myrna J. 
Published: June 2018

Abstract

Anthropogenic activity is increasing the presence of contaminants that enter waterways through wastewater effluent and urban and/or agricultural runoff, generally in complex mixtures. Depending on the mode of action of the individual contaminant within the mixture, toxicity can occur due to contaminants having similar or dissimilar modes of action. However, it is unknown how the metabolome responds to sublethal contaminant mixtures in the keystone genus Daphnia. In the present study we examined D. magna metabolic responses to acute sublethal exposure of propranolol, carbamazepine, and perfluorooctanesulfonic acid (PFOS) as well as in binary (propranolol–carbamazepine, propranolol–PFOS, carbamazepine–PFOS) and tertiary mixtures (carbamazepine–propranolol–PFOS), all at 10% of the median lethal concentration of the population (LC50). The metabolome was measured using 1H nuclear magnetic resonance (NMR) and characterized using principal component analysis, regression analysis, and fold changes in metabolite relative to the unexposed (control) group. The averaged principal component analysis scores plots revealed that carbamazepine–PFOS and carbamazepine–propranolol–PFOS exposures were significantly different from the control treatment. After normalizing the toxicity of each contaminant, we found that some metabolites responded monotonically, whereas others displayed a nonmonotonic response with increasing toxicity units. The single contaminant exposures and 2 binary mixtures (propranolol–carbamazepine, and propranolol–PFOS) resulted in minimal changes in the identified metabolites, whereas the carbamazepine–PFOS and carbamazepine–propranolol–PFOS displayed increases in several amino acid metabolites and decreases in glucose. Overall, our results highlight the sensitivity of the metabolome to distinguish the composition of the contaminant mixtures, with some mixtures displaying heightened responses versus others. Environ Toxicol Chem 2018;37:2448–2457. © 2018 SETAC
Effects of low, subchronic exposure of 2,4-Dichlorophenoxyacetic acid (2,4-D) and commercial 2,4-D formulations on early life stages of fathead minnows (Pimephales promelas)
Authors: Dehnert Gavin K. , Freitas Mariella B. , DeQuattro Zachary A. , Barry Terence , Karasov William H. 
Published: June 2018

Abstract

Aquatic herbicides are commonly used to control a wide variety of algae and plants, but they also have the potential to contaminate and affect nontarget organisms. However, the impacts of low-level 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide exposure on larval fish are not well understood. We conducted a series of experiments to determine the effects of low concentrations (0.05, 0.50, and 2.00 ppm) of 2 commercial 2,4-D amine salt herbicide formulations (Weedestroy® AM40 [WAM40] and DMA® 4 IVM [DMA4]) and pure 2,4-D on the development and survival of fathead minnows (Pimephales promelas) at various life cycle stages. Larval survival (30 d post hatch [dph]) was decreased following exposure of eggs and larvae to pure 2,4-D (0.50 ppm; p ≤ 0.001), as well as to WAM40 (0.50 and 2.00 ppm; p ≤ 0.001, p ≤ 0.001) and DMA4 (0.50 and 2.00 ppm; p ≤ 0.001, p ≤ 0.001). The results also narrowed the critical window of exposure for effects on survival to the period between fertilization and 14 dph. Development was not negatively altered by any of the compounds tested, although the commercial formulations increased larval total length and mass at 2.00 ppm. Altogether, the results indicate that the use of 2,4-D herbicides for weed control in aquatic ecosystems at current recommended concentrations (&lt;2 ppm whole lake; &lt;4 ppm spot treatment) could present risks to fathead minnow larval survival. Environ Toxicol Chem 2018;37:2550–2559. © 2018 SETAC