bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Water on the Activity of Magnesium Silicate for Transesterification Reactions
Authors: Lin Longfei , Cornu Damien , Mounir Daou Maya , Domingos Cyril , Herledan Virginie , Krafft Jean‐Marc , Laugel Guillaume , Millot Yannick , Lauron‐Pernot Hélène 
Published: April 2017

AbstractThis study aims to reveal how water adsorbed on to a solid can influence its catalytic properties for transesterification in liquid phase. A commercial magnesium silicate was subjected to a range of thermal pretreatments and used for the transesterification of ethyl acetate with methanol. Conversion of ethyl acetate decreased with increasing pretreatment temperature, in direct relation to the release of the water content of the magnesium silicate. Thermogravimetric analysis, diffuse reflectance infrared Fourier transform (DRIFT), and 1H NMR spectroscopies revealed that physically adsorbed water had little influence on the reactivity. The water incorporated within the catalysts, however, which desorbs at higher temperatures, played a key role on the conversion. Calorimetry, in situ DRIFT spectroscopy, and 1H NMR characterization indicate that two kinds of active site exist. These are created from the water coordinated to magnesium located on the edge of the clay‐like particles or in the defects present in the silicate layer, respectively. Their role could be to stabilize methanol deprotonated by basic Mg‐OH groups, activate the ester, or help the departure of the alkoxyl moiety.
All‐Solid‐State Double‐Layer Capacitors Using Binderless Reduced Graphene Oxide Thin Films Prepared by Bipolar Electrochemistry
Authors: Allagui Anis , Ashraf Juveiriah Mohammed , Khalil Malathe , Abdelkareem Mohammad Ali , Elwakil Ahmed S. , Alawadhi Hussain 
Published: April 2017

AbstractBipolar electrochemistry is used as an economical, single‐step, and scalable process for the oxidation of a wireless graphite substrate, and the subsequent electrophoretic deposition of graphene oxide thin film on a second wireless substrate. An all‐solid‐state symmetric double‐layer capacitor (EDLC) using binderless reduced graphene oxide electrodes exhibited outstanding reversibility and capacitance retention over 18000 cycles, as well as superior capacitive behavior at far‐from‐dc frequencies (for example 45 and 47
F cm
), effective capacitances at 75 and 189 Hz, respectively (computed using a series resonance network with ideal inductors), compared to 55
F cm
at close‐to‐dc (computed from cyclic voltammetry at 10 mV s
). This makes the device well‐suited for ac filtering applications. A one‐hour thermal treatment of the electrodes at 900 °C under vacuum increased the capacitance 13‐fold (719
F cm
) at close‐to‐dc, which decreased to 185 and 150
F cm
as the frequency was increased to 37 and 106 Hz, respectively These properties make this device suitable for both reasonable dc energy storage and higher frequency applications.
In Situ Gold‐Loaded Fluorinated Titania Inverse Opal Photocatalysts for Enhanced Solar‐Light‐Driven Hydrogen Production
Authors: Rahul Theyyathum Kavil , Sandhyarani Neelakandapillai 
Published: April 2017

AbstractThis work reports the preparation of in situ gold‐loaded fluorinated titania inverse opal (Au/F TiO2 IO) photocatalysts for enhancing solar‐light‐driven hydrogen evolution. The use of trifluoroacetic acid facilitates the surface fluorination as well as the in situ deposition of gold nanoparticles (AuNPs) at the defect sites on the TiO2 surface. The thermal treatment partially fuses the gold and titania nanoparticles leading to enhanced hot electron injection when illuminated under solar light. Au/F TiO2 IO‐215 prepared using polystyrene (PS) spheres of 215 nm size are demonstrated to be able to enhance the hydrogen evolution five‐fold relative to nanocrystalline titania photocatalyst (Au/F nc‐TiO2) due to the electronic band gap (EBG) absorption of TiO2 within the photonic band gap (PBG). Au/F TiO2 IO‐460; with the blue edge of the PBG closer to the localized surface plasmon resonance (LSPR) region of AuNPs displayed four‐fold enhancement in the hydrogen evolution with respect to Au/F nc‐TiO2. The solar light driven hydrogen evolution rates obtained for Au/F TiO2 IO‐215 and Au/F TiO2 IO‐460 photocatalysts (58.86 and 49.43 mmol h−1 g−1 respectively) are remarkably higher than the rates of inverse‐opal‐assisted hydrogen evolution experiments reported in literature. This work demonstrated a strategy for synergistically enhancing the solar light harvesting by the restructuring of Au/F TiO2 photocatalysts into inverse opals. The extended hydrogen yield by Au/F TiO2 IOs is on the order of millimoles, making them potential photocatalysts for solar hydrogen production.
Pitfall trap sampling bias depends on body mass, temperature, and trap number: insights from an individual‐based model
Authors: Engel Jan , Hertzog Lionel , Tiede Julia , Wagg Cameron , Ebeling Anne , Briesen Heiko , Weisser Wolfgang W. 
Published: April 2017

AbstractThe diversity and community composition of ground arthropods is routinely analyzed by pitfall trap sampling, which is a cost‐ and time‐effective method to gather large numbers of replicates but also known to generate data that are biased by species‐specific differences in locomotory activity. Previous studies have looked at factors that influence the sampling bias. These studies, however, were limited to one or few species and did rarely quantify how the species‐specific sampling bias shapes community‐level diversity metrics. In this study, we systematically quantify the species‐specific and community‐level sampling bias with an allometric individual‐based model that simulates movement and pitfall sampling of 10 generic ground arthropod species differing in body mass. We perform multiple simulation experiments covering different scenarios of pitfall trap number, spatial trap arrangement, temperature, and population density. We show that the sampling bias decreased strongly with increasing body mass, temperature, and pitfall trap number, while population density had no effect and trap arrangement only had little effect. The average movement speed of a species in the field integrates body mass and temperature effects and could be used to derive reliable estimates of absolute species abundance. We demonstrate how unbiased relative species abundance can be derived using correction factors that need only information on species body mass. We find that community‐level diversity metrics are sensitive to the particular community structure, namely the relation between body mass and relative abundance across species. Generally, pitfall trap sampling flattens the rank‐abundance distribution and leads to overestimations of ground arthropod Shannon diversity. We conclude that the correction of the species‐specific pitfall trap sampling bias is necessary for the reliability of conclusions drawn from ground arthropod field studies. We propose bias correction is a manageable task using either body mass to derive unbiased relative abundance or the average speed to derive reliable estimates of absolute abundance from pitfall trap sampling.
An energy stable monolithic Eulerian fluid‐structure finite element method
Authors: Hecht Frédéric , Pironneau Olivier 
Published: April 2017

SummaryWhen written in an Eulerian frame, the conservation laws of continuum mechanics are similar for fluids and solids leading to a single set of variables for a monolithic formulation. Such formulations are well adapted to large displacement fluid‐structure configurations, but stability is a challenging problem because of moving geometries. In this article, the method is presented; time implicit discretizations are proposed with iterative algorithms well posed at each step, at least for small displacements; stability is discussed for an implicit in time finite element method in space by showing that energy decreases with time. The key numerical ingredient is the Characterics‐Galerkin method coupled with a powerful mesh generator. A numerical section discusses implementation issues and presents a few simple tests. It is also shown that contacts are easily handled by extending the method to variational inequalities. This paper deals only with incompressible neo‐Hookean Mooney‐Rivlin hyperelastic material in 2 dimensions in a Newtonian fluid, but the method is not limited to these; compressible and 3D cases will be presented later.
Exploring the flavor life cycle of beers with varying alcohol content
Authors: Missbach Benjamin , Majchrzak Dorota , Sulzner Raphael , Wansink Brian , Reichel Martin , Koenig Juergen 
Published: April 2017

AbstractDecreasing alcohol in beer and increasing the pleasure of lower alcohol beers is a potential way to limit total alcohol consumption. Consumers’ willingness to drink alcohol‐reduced beers is mainly limited by unfavorable flavor characteristics that arise during consumption. To investigate the temporal flavor dominance during consumption, we analyzed the five most dominant beer flavors from nine different beers among three types of beer with varying alcohol content to assess the Flavor Life Cycle. Results show that beers with different alcohol content displayed similar flavor dominance (e.g., bitterness) and displayed differences in worty‐off flavor, malty flavor, and astringency. In alcohol‐free beers, worty‐off flavor was most pronounced in dominating between 5 and 30 s and malty flavor increased after swallowing. For bitterness and astringency, higher alcohol content resulted in higher flavor dominance, especially prior to swallowing (≤40 sec). Based on these findings, we provide some brief advice to minimize unfavorable flavor experience during consumption of beer with lower alcohol. For now, consumers who want to enjoy beers with lower alcohol should consider flavor changes and focus on the favored and defocus on the less favored flavors.
Investigation of the thermal regime and subsurface properties of a tidally affected, variably saturated streambed
Authors: Halloran Landon J. S. , Andersen Martin S. , Rau Gabriel C. 
Published: April 2017

AbstractTemperature and moisture content in the variably saturated subsurface are two of the most important physical parameters that govern a wide variety of geochemical and ecological processes. An understanding of thermal and hydraulic processes and properties of transient vadose zones is therefore fundamental in the evaluation of such processes. Here, an investigation of the thermal regime and subsurface properties of a tidally affected, variably saturated streambed is presented. Field and laboratory measurements, as well as a forward numerical model, are jointly employed in the investigation. Temperature, soil moisture, surface level, and water level data were recorded in a transect perpendicular to a tidally driven stream. Frequency‐domain analysis of the subsurface temperature measurements revealed the rapid decay of the tidal temperature driver within the top ∼30 cm of sediment. Several techniques were used to evaluate subsurface thermal and hydraulic properties, including thermal conductivity and the soil water retention curve. These properties were used to constrain a forward numerical model that included coupled treatment of relevant variable saturation thermal and hydraulic physics. Even though the investigated vadose zone is intermittent and relatively shallow (
20 cm), the results illustrate how error can be introduced into heat‐transport calculations if unsaturated conditions are not taken into account.
p53‐competent cells and p53‐deficient cells display different susceptibility to oxygen functionalized graphene cytotoxicity and genotoxicity
Authors: Petibone Dayton M. , Mustafa Thikra , Bourdo Shawn E. , Lafont Andersen , Ding Wei , Karmakar Alokita , Nima Zeid A. , Watanabe Fumiya , Casciano Daniel , Morris Suzanne M. , Dobrovolsky Vasily N. , Biris Alexandru S. 
Published: April 2017

AbstractDue to the distinctive physical, electrical, and chemical properties of graphene nanomaterials, numerous efforts pursuing graphene‐based biomedical and industrial applications are underway. Oxidation of pristine graphene surfaces mitigates its otherwise hydrophobic characteristic thereby improving its biocompatibility and functionality. Yet, the potential widespread use of oxidized graphene derivatives raises concern about adverse impacts on human health. The p53 tumor suppressor protein maintains cellular and genetic stability after toxic exposures. Here, we show that p53 functional status correlates with oxygen functionalized graphene (f‐G) cytotoxicity and genotoxicity in vitro. The f‐G exposed p53‐competent cells, but not p53‐deficient cells, initiated G0/G1 phase cell cycle arrest, suppressed reactive oxygen species, and entered apoptosis. There was p53‐dependent f‐G genotoxicity evident as increased structural chromosome damage, but not increased gene mutation or chromatin loss. In conclusion, the cytotoxic and genotoxic potential for f‐G in exposed cells was dependent on the p53 functional status. These findings have broad implications for the safe and effective implementation of oxidized graphene derivatives into biomedical and industrial applications. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
A novel technique for decellularization of allogenic nerves and in vivo study of their use for peripheral nerve reconstruction
Authors: Boriani F. , Fazio N. , Fotia C. , Savarino L. , Nicoli Aldini N. , Martini L. , Zini N. , Bernardini M. , Baldini N. 
Published: April 2017

AbstractAutografts represent the gold standard for peripheral nerve reconstruction but their limited availability, the discrepancy of nerve caliber, and long surgical times are drawbacks. Allografts have therefore become a valid alternative option. In particular, acellular nerve allografts (ANAs) rather than fresh allografts do not need immunosuppression and appear to be safe and effective based on recent studies. An innovative method was conceived to obtain ANAs, so as to speed up nerve decellularization, without compromising nerve architecture, and without breaking the asepsis chain. Several detergent‐based techniques, integrated with sonication and mechanical stirring, were tested in vitro on rabbit nerves, to identify, by microscopy and immunohistochemistry, the most effective protocol in terms of cell lysis and cellular debris clearance, while maintaining nerve architecture. Furthermore, a pilot in vivo study was performed: ANAs were implanted into tibial nerve defects of three rabbits, and autografts, representing the gold standard, in other three animals. Twelve weeks postoperatively, rabbits were clinically evaluated and euthanasized; grafts were harvested and microscopically and histomorphometrically analyzed. The method proved to be effective in vitro: the treatment removed axons, myelin and cells, without altering nerve architecture. The in vivo study did not reveal any adverse effect: animals maintained normal weight and function of posterior limb during the entire experimental time. A mild fibrotic reaction was observed, macrophages and leukocytes were rare or absent; ANAs regenerated fascicles and bundles were comparable versus autografts. Based on these results, this decellularization protocol is encouraging and deserves deeper investigations with further preclinical and clinical studies. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2228–2240, 2017.
High Dose Supplementation of Vitamin D Affects Measures of Systemic Inflammation: Reductions in High Sensitivity C‐Reactive Protein Level and Neutrophil to Lymphocyte Ratio (NLR) Distribution
Authors: Tabatabaeizadeh Seyed‐Amir , Avan Amir , Bahrami Afsane , Khodashenas Ezzat , Esmaeili Habibollah , Ferns Gordon A. , Abdizadeh Mojtaba Fattahi , Ghayour‐Mobarhan Majid 
Published: April 2017

ABSTRACTThe prevalence of Vitamin D deficiency is increasing worldwide, which has be shown to be associated with increased risk of cardiovascular disease (CVD), autoimmune disease, and metabolic syndrome. These conditions are also associated with a heightened state of inflammation. The aim of the current study was to evaluate the effect of vitamin D supplementation on serum C‐Reactive Protein (CRP) level and Neutrophil‐to‐lymphocyte ratio (NLR) distribution in a large cohort of adolescent girls. A total of 580 adolescent girls were recruited follow by evaluation of CRP and hematological parameters before and after supplementation with vitamin D supplements as 9 of 50000 IU cholecalciferol capsules for 9 weeks taken at weekly intervals. At baseline, serum hs‐CRP level was 0.9 (95%CI: 0.5–1.8), while this value after intervention was reduced to 0.8 (95%CI: 0.3–1.6; P = 0.007). Similar results were also detected for NLR (e.g., NLR level was 1.66 ± 0.72 and 1.53 ± 0.67, P = 0.002, before and after therapy with compliance rate of >95.2%). Moreover, we found an association between hs‐CRP and BMI, triglyceride, white blood cell count, and lymphocytes. Interestingly we observed a significant reduction in neutrophil count and CRP level after high dose vitamin D supplementation. Our findings showed that the high dose supplementation of vitamin D affects measures of systemic inflammation: reductions in High Sensitivity C‐Reactive Protein level and Neutrophil‐to‐lymphocyte ratio (NLR) distribution. J. Cell. Biochem. 118: 4317–4322, 2017. © 2017 Wiley Periodicals, Inc.
Psychomotor Tremor and Proprioceptive Control Problems in Current and Former Stimulant Drug Users: An Accelerometer Study of Heavy Users of Amphetamine, MDMA, and Other Recreational Stimulants
Authors: Downey Luke A. , Tysse Brenda , Ford Talitha C. , Samuels Angela C. , Wilson Rory P. , Parrott Andrew C. 
Published: April 2017

AbstractThe recreational use of various stimulant drugs has been implicated in the development of movement disorders through dysregulation of the dopaminergic and serotoninergic neurotransmitter systems. The present study investigated psychomotor differences in current and former recreational stimulant drug users compared with nonusing controls. Sixty participants comprised 3 groups: 20 current stimulant drug users (CSUs; 11 men, aged 31.4 ± 9.1 years), 20 former stimulant drug users (FSUs; 5 men, aged 39.1 ± 8.5 years), and 20 nonuser controls (NUCs; 5 men, aged 35.7 ± 6.4 years). Psychomotor arm steadiness for each participant was assessed with a wrist‐attached accelerometer during 5 arm positions with eyes open and then eyes closed. Arm‐drop of arm position was indicated by the arm longitudinal rotation axis (ALoRA), and tremor was indicated by the overall vector of dynamic body acceleration (VeDBA). Overall, CSUs performed the most poorly on ALoRA (P < .05) and VeDBA indices (P < .05), and FSUs perform almost as poorly on VeDBA indices (P < .05) compared with NUCs. It was concluded that stimulant drug use, primarily MDMA and amphetamines, may result in acute stimulant‐induced tremor as well as long‐term proprioceptive deficits in terms of arm‐droop.
Effect of platinum on sintering morphology of porous YSZ ceramics
Authors: Fang Pan , Wang Junmei , Li Xian , Wu Shijie , Zhang Wenlei , Li Sufang 
Published: April 2017

AbstractPlatinum/yttria‐stabilized zirconia (Pt/YSZ) porous ceramics were prepared by sintering of the Pt/PMMA/YSZ stripe‐like membrane with a porogen of spherical polymethyl methacrylate (PMMA) and a precursor of platinum (Pt) of chloroplatinic acid. The microstructure of raw and processed material and Pt/ZrO2 calcination process at different sintering temperatures were investigated. The results showed that the spherically porous structure of Pt/YSZ was observed at a sintering temperature below 400 °C due to the thermal decomposition of PMMA. However, the pores were shrunk about 35% in diameter when YSZ compacts were sintered at the temperature of 1,450 °C. In addition, the spherical pores can be retained in the compacts when the content of Pt <5% and then gradually merged into changing when the content of Pt increased to 50%. The relative density was increased from 42% to 90% and the open porosity was decreased from 60% to 10% when Pt was added with content from 5% to 80%. The change of microstructure for Pt/YSZ is due to the migration of Pt and YSZ in the composites. The preferential migration and coalescence proceeded for Pt in Pt/YSZ is about 500 °C and YSZ clusters can keep stable until up to 900 °C. However, the growth of YSZ particle in the sintering process was hindered by the scattering of Pt phase.
Long‐term study of the occurrence and time of passage of sea breeze in São Paulo, 1960–2009
Authors: Perez Gabriel M. P. , Silva Dias Maria A. F. 
Published: April 2017

ABSTRACTThis paper presents a simple methodology to identify sea breeze frontal passage in the city of São Paulo, Brazil, based in hourly wind direction data. Fifty‐year time series of annual frequency of sea breeze frontal passage and of its time of arrival in São Paulo are generated and related to global climate indicators and local variables. The frequency of occurrence and time of arrival of sea breeze shows long‐term oscillations in the interannual and decadal time scales. Multiple regression is used to identify the variables that explain the observed variance of both frequency of occurrence and timing of the sea breeze in São Paulo. Local variables such as air temperature in São Paulo and sea surface temperature (SST) in the vicinity of the coast explain more than 95% of the total R2 (R2 = 51%) in a multiple regression model of the frequency of sea breeze frontal passage. Global climate indices such as the Atlantic Multidecadal Oscillation, the Southern Oscillation Index (SOI) and the Pacific Decadal Oscillation explain about 85% of the total R2 (R2 = 52%) in a multiple regression model of the time of arrival of the sea breeze in São Paulo. The sea breeze circulation is shown to impact the rainfall in São Paulo and vicinity and to be associated with extreme rainfall events.
Characterization of the Medieval Climate Anomaly, Little Ice Age and recent warming in northern Lapland
Authors: Luoto Tomi P. , Kivilä E. Henriikka , Rantala Marttiina V. , Nevalainen Liisa 
Published: April 2017

ABSTRACTThe major climate events of the Common Era (CE) have global imprints but significant variations in their timing and magnitude have been suggested. For reliable assessments of the past climate patterns and their applications for evaluations of the ongoing changes, spatially comprehensive network of high‐fidelity paleorecords are necessary. In this study, we reconstruct summer air temperatures of the past 2000 years from northern Lapland (Utsjoki, Finland). We use fossil Chironomidae (Diptera) assemblages from sediments of a remote subarctic lake (Loažžejávri) and the transfer function approach for quantitative temperature reconstruction. The results indicate that the Chironomidae fauna were responding to air temperature and the core assemblages had good modern analogues in the calibration set allowing reliable paleoclimate reconstruction. In our reconstruction, a warm period between ∼900 and 1300 CE is synchronous with the globally defined extent of the Medieval Climate Anomaly (MCA), though beginning considerably later than previously reconstructed for eastern Scandinavia. The MCA was also relatively mild, as the temperatures were only 0.5 °C higher than the record average. Similar to eastern Scandinavia, a cold period corresponding to the Little Ice Age (LIA) was longer that typically observed in hemispheric reconstructions beginning already at ∼1400 CE and lasting very close to modern times. We also found confirming evidence that the LIA was interrupted by a short‐lived warmer period dividing it into two separate cold events in the region. Based on our results, the present is warmer than during any time of the MCA displaying how rapid and severe the ongoing climate change is.