bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium Nanoparticles Embedded into Graphene Nanosheets: Preparation, Characterization, and Nonenzymatic Electrochemical Detection of H2O2
Authors: Liu Hongfang , Chen Xianlan , Huang Linhong , Wang Jian , Pan Haibo 
Published: February 2014

AbstractA novel nonenzymatic H2O2 sensor based on a palladium nanoparticles/graphene (Pd‐NPs/GN) hybrid nanostructures composite film modified glassy carbon electrode (GCE) was reported. The composites of graphene (GN) decorated with Pd nanoparticles have been prepared by simultaneously reducing graphite oxide (GO) and K2PdCl4 in one pot. The Pd‐NPs were intended to enlarge the interplanar spacing of graphene nanosheets and were well dispersed on the surface or completely embedded into few‐layer GN, which maintain their high surface area and prevent GN from aggregating. XPS analysis indicated that the surface Pd atoms are negatively charged, favoring the reduction process of H2O2. Moreover, the Pd‐NPs/GN/GCE could remarkably decrease the overpotential and enhance the electron‐transfer rate due to the good contact between Pd‐NPs and GN sheets, and Pd‐NPs have high catalytical effect for H2O2 reduction. Amperometric measurements allow observation of the electrochemical reduction of H2O2 at 0.5 V (vs. Ag/AgCl). The H2O2 reduction current is linear to its concentration in the range from 1×10−9 to 2×10−3 M, and the detection limit was found to be 2×10−10 M (S/N=3). The as‐prepared nonenzymatic H2O2 sensor exhibits excellent repeatability, selectivity and long‐term stability.
Electrochemical Detection of Nitrite in Meat and Water Samples Using a Mesoporous Carbon Ceramic SiO2/C Electrode Modified with In Situ Generated Manganese(II) Phthalocyanine
Authors: Rahim Abdur , Santos Lucas S. S. , Barros Sergio B. A. , Kubota Lauro T. , Landers Richard , Gushikem Yoshitaka 
Published: February 2014

AbstractMesoporous carbon ceramic SiO2/50 wt % C (SBET=170 m2 g−1), where C is graphite, were prepared by the sol‐gel method. The materials were characterized using N2 sorption isotherms, scanning electron microscopy, and conductivity measurements. The matrix was used as support for the in situ immobilization of Mn(II) phthalocyanine (MnPc) on their surface. XPS was used to determine the Mn/Si atomic ratios of the MnPc‐modified materials. Pressed disk electrodes were prepared with the MnPc‐modified matrix, and tested as an electrochemical sensor for nitrite oxidation. The linear response range, sensitivity, detection limit and quantification limit were 0.79–15.74 µmol L−1, 17.31 µA L µmol−1, 0.02 µmol L−1 and 0.79 µmol L−1, respectively, obtained using cyclic voltammetry. The repeatability of the proposed sensor, evaluated in terms of relative standard deviation was 1.7 % for 10 measurements of a solution of 12.63 µmol L−1 nitrite. The sensor employed to determine nitrite in sausage meat, river and lake water samples showed to be a promising tool for this purpose.
Poly‐ε‐Lysine Modified Nanocarbon Film Electrodes for LPS Detection
Authors: Kato Dai , Oda Atsumu , Tanaka Mutsuo , Iijima Seiichiro , Kamata Tomoyuki , Todokoro Masami , Yoshimi Yasuo , Niwa Osamu 
Published: February 2014

AbstractWe developed an electrochemical system for detecting lipopolysaccharide (LPS) that uses an ultraflat nanocarbon film electrode modified with poly‐ε‐lysine with a high affinity to LPS. LPS was captured on the modified electrode, and then ferrocene labeled polymyxin B (FcPMB) was captured on the LPS adsorbed electrode via the LPS‐PMB affinity interaction. The adsorbed FcPMB provided an amplified response with Fe2+ ions, and the current response was dependent on the amount of captured LPS (LOD=2.0 ng/mL). This was due to the efficient accumulation of the obtained current for LPS and the very low noise made possible by the ultraflat surface.
Biotransformation of trinitrotoluene (TNT) by Pseudomonas spp. isolated from a TNT-contaminated environment
Authors: Chien Chih-Ching , Kao Chih-Ming , Chen De-Yu , Chen Ssu Ching , Chen Chien-Cheng 
Published: February 2014

Abstract

The compound 2,4,6-trinitrotoluene (TNT) is a secondary explosive widely used worldwide for both military and civil purposes. As a result, residual TNT has been detected as an environmental pollutant in both soil and groundwater. The authors have isolated several microbial strains from soil contaminated with TNT by enrichment culture techniques using TNT as a carbon, nitrogen, and energy source. The contaminated soil contained approximately 1860 ppm TNT measured by high-performance liquid chromatography (HPLC). The initial identification of these isolates was determined by 16S rRNA gene comparison. The isolates mainly included species belonging to the genus Pseudomonas. Two strains (Pseudomonas putida strain TP1 and Pseudomonas aeruginosa strain TP6) were selected for further examination. Both strains demonstrated the ability to grow on the medium containing TNT as a carbon, energy, and nitrogen source and also clearly demonstrated the ability to degrade TNT. More than 90% of the TNT in the growth medium was degraded by both strains after 22 d incubation, as determined by HPLC. Additionally, the resting cells of P. putida TP1 and P. aeruginosa TP6 both significantly displayed the ability to transform (metabolize) TNT. Environ Toxicol Chem 2014;33:1059–1063. © 2014 SETAC
Psychological functioning 1 year after a brief intervention using micronutrients to treat stress and anxiety related to the 2011 Christchurch earthquakes: a naturalistic follow‐up
Authors: Rucklidge Julia J. , Blampied Neville , Gorman Brigette , Gordon Heather A. , Sole Ellen 
Published: February 2014

ObjectiveWe investigated whether micronutrients given acutely following the Christchurch earthquakes continued to confer benefit 1 year following the treatment.MethodsSixty‐four adults from the original 91 participants experiencing heightened anxiety or stress 2–3 months following the 22nd February 2011 earthquake and who had been randomized to receive three different doses of micronutrients completed on‐line questionnaires assessing mood, anxiety, stress, and symptoms associated with post‐traumatic stress disorder 1 year after completing the initial study. Twenty‐one out of 29 nonrandomized controls who did not receive the treatment also completed the questionnaires.ResultsBoth the treated and control groups experienced significant improvement in psychological functioning compared with end‐of‐trial. However, treated participants had better long‐term outcomes on most measures compared with controls (ES = 0.69–1.31). Those who stayed on micronutrients through to follow‐up or stopped all treatment reported better psychological functioning than those who switched to other treatments including medications. About 10% of the sample continued to have post‐traumatic stress disorder symptoms.ConclusionsDisaster survivors improve psychologically over time regardless of receiving intervention; however, those taking micronutrients during the acute phase following a disaster show better outcomes, identifying micronutrients as a viable treatment for acute stress following a natural disaster with maintenance of benefits 1 year later. ACTRN 12611000460909 Copyright © 2014 John Wiley & Sons, Ltd.
Ultrastructural characteristics of 5BrdU labeling retention cells including stem cells of regenerating feathers in chicken
Authors: Alibardi Lorenzo , Wu Ping , Chuong Cheng‐Ming 
Published: February 2014

ABSTRACTFeathers regenerate from stem cells localized in a region of the follicle indicated as the bulge of the collar. Stem cells are slow cycling cells and some of these cells can be identified after labeling experiments using 5‐bromo‐deoxyuridine to detect label retaining cells (5BrdU LRCs). The present electron microscopic analysis of 5BrdU LRCs has described the ultrastructural characteristics of small cells present in the bulge region of the follicle in regenerating feathers of chickens that include stem cells. Labeled feather stem cells are smaller than 10 μm in average diameter, possess large nuclei with high nuclear/cytoplasmic ratio, and contain evenly distributed ribosomes, sparse bundles of intermediate filaments, scarce or no endoplasmic reticulum, and few mitochondria. The nuclei are mainly euchromatic with a variable amount of heterochromatin clumps and the nucleoli show developed granular and fibrillar components. These features indicate that feather stem cells are transcriptionally active cells for ribosomal and proteins synthesis. The cell surface of feather stem cells often shows small and irregular folds resembling microvilli in contact with the surrounding cells. The latter characteristics may be related to the exchange of molecules and/or with the migration of stem cells among other epithelial cells of the collar epithelium. J. Morphol. 275:768–774, 2014. © 2014 Wiley Periodicals, Inc.
Nutrient limitation of alpine plants: Implications from leaf N : P stoichiometry and leaf δ15N
Authors: Xu Xingliang , Wanek Wolfgang , Zhou Caiping , Richter Andreas , Song Minghua , Cao Guangmin , Ouyang Hua , Kuzyakov Yakov 
Published: February 2014

AbstractNitrogen (N) deposition can affect grassland ecosystems by altering biomass production, plant species composition and abundance. Therefore, a better understanding of the response of dominant plant species to N input is a prerequisite for accurate prediction of future changes and interactions within plant communities. We evaluated the response of seven dominant plant species on the Tibetan Plateau to N input at two levels: individual species and plant functional group. This was achieved by assessing leaf N : P stoichiometry, leaf δ15N and biomass production for the plant functional groups. Seven dominant plant species—three legumes, two forbs, one grass, one sedge—were analyzed for N, P, and δ15N 2 years after fertilization with one of the three N forms: NO$ _3^- $, NH$ _4^+ $, or NH4NO3 at four application rates (0, 7.5, 30, and 150 kg N ha–1 y–1). On the basis of biomass production and leaf N : P ratios, we concluded that grasses were limited by available N or co‐limited by available P. Unlike for grasses, leaf N : P and biomass production were not suitable indicators of N limitation for legumes and forbs in alpine meadows. The poor performance of legumes under high N fertilization was mainly due to strong competition with grasses. The total above‐ground biomass was not increased by N fertilization. However, species composition shifted to more productive grasses. A significant negative correlation between leaf N : P and leaf δ15N indicated that the two forbs Gentiana straminea and Saussurea superba switched from N deficiency to P limitation (e.g., N excess) due to N fertilization. These findings imply that alpine meadows will be more dominated by grasses under increased atmospheric N deposition.
Effects of tillage and application of cattle slurry on carbon pools and aggregate distribution in temperate grassland soils
Authors: Linsler Deborah , Geisseler Daniel , Loges Ralf , Taube Friedhelm , Ludwig Bernard 
Published: February 2014

AbstractThe objective was to study the effects of tillage and cattle slurry application on organic C dynamics in grassland soils. Treatments included long‐term grassland and reinstalled grassland (after tillage and winter wheat cropping) with and without cattle slurry application (240 kg N ha–1 y–1). A period of 4 y slurry application sufficed to increase microbial activity 1.6‐fold in surface soil (0–10 cm). Tillage affected aggregate distribution and basal respiration in the surface soil.
Robust 4D flow denoising using divergence‐free wavelet transform
Authors: Ong Frank , Uecker Martin , Tariq Umar , Hsiao Albert , Alley Marcus T , Vasanawala Shreyas S. , Lustig Michael 
Published: February 2014

PurposeTo investigate four‐dimensional flow denoising using the divergence‐free wavelet (DFW) transform and compare its performance with existing techniques.Theory and MethodsDFW is a vector‐wavelet that provides a sparse representation of flow in a generally divergence‐free field and can be used to enforce “soft” divergence‐free conditions when discretization and partial voluming result in numerical nondivergence‐free components. Efficient denoising is achieved by appropriate shrinkage of divergence‐free wavelet and nondivergence‐free coefficients. SureShrink and cycle spinning are investigated to further improve denoising performance.ResultsDFW denoising was compared with existing methods on simulated and phantom data and was shown to yield better noise reduction overall while being robust to segmentation errors. The processing was applied to in vivo data and was demonstrated to improve visualization while preserving quantifications of flow data.ConclusionDFW denoising of four‐dimensional flow data was shown to reduce noise levels in flow data both quantitatively and visually. Magn Reson Med 73:828–842, 2015. © 2014 Wiley Periodicals, Inc.
The modified rankin scale to assess disability in myasthenia gravis: Comparing with other tools
Authors: Farrugia Maria E. , Carmichael Caroline , Cupka Bryan J. , Warder Judy , Brennan Kathryn M. , Burns Ted M. 
Published: February 2014

ABSTRACTIntroduction: We explored the modified Rankin scale (mRS) as a tool to quantitate disability in myasthenia gravis (MG). Our aim was to correlate patients' perception of their disability with that of the care provider and determine its relationship with other MG‐related scores. Methods: We evaluated 107 MG patients at 2 neurological centers. Patients were assessed over the telephone before and after clinic visits using the 15‐item Myasthenia Gravis Quality‐of‐Life index (MG‐QOL15) and mRS. At the clinic, patients were assessed using the MG‐QOL15, MG Composite (MGC), and mRS. Results: The MG‐QOL15 correlated with the MGC, mRS, and assessors' scores of patients. Assessors' perception of disease burden was in line with that of the patients' scoring. MG‐QOL15 scores obtained over the telephone were consistent with those obtained in the clinic. Scores were generally higher in patients receiving steroids at >5 mg/day and in those receiving or seeking benefits. Conclusion: The MG‐QOL15 and mRS are useful for estimating disability in MG. Muscle Nerve 50: 501–507, 2014
Dispersion analysis of plane wave discontinuous Galerkin methods
Authors: Gittelson Claude J. , Hiptmair Ralf 
Published: February 2014

SUMMARYThe plane wave DG (PWDG) method for the Helmholtz equation was introduced and analyzed in [GITTELSON, C., HIPTMAIR, R., AND PERUGIA, I. Plane wave discontinuous Galerkin methods: analysis of the h‐version. Math. Model. Numer. Anal. 43 (2009), 297–331] as a generalization of the so‐called ultra‐weak variational formulation, see [O. CESSENAT AND B. DESPRéS, Application of an ultra weak variational formulation of elliptic PDEs to the two‐dimensional Helmholtz equation, SIAM J. Numer. Anal., 35 (1998), pp. 255–299]. The method relies on Trefftz‐type local trial spaces spanned by plane waves of different directions, and links cells of the mesh through numerical fluxes in the spirit of DG methods.We conduct a partly empirical dispersion analysis of the method in a discrete translation‐invariant setting by studying the mismatch of wave numbers of discrete and continuous plane waves traveling in the same direction. We find agreement of the wave numbers for directions represented in the local trial spaces. For other directions, the PWDG methods turn out to incur both phase and amplitude errors. This manifests itself as a pollution effect haunting the h‐version of the method. Our dispersion analysis allows a quantitative prediction of the strength of this effect and its dependence on the wave number and number of plane waves. Copyright © 2014 John Wiley & Sons, Ltd.
The incorporation of gradient damage models in shell elements
Authors: Hosseini Saman , Remmers Joris J.C. , de Borst René 
Published: February 2014

SUMMARYAn approach is proposed to incorporate gradient‐enhanced damage models in shell elements. The approach is elaborated for a solid‐like shell element, which is advantageous because of the availability of nodes at the top and bottom shell surfaces, and the presence of a three‐dimensional strain state. Some simple examples are given to demonstrate the versatility and the convergence of the method. Copyright © 2014 John Wiley & Sons, Ltd.
Soft nanoparticles assembled from linear poly(ethylene glycol) and linear brush polydimethylsiloxane diblock copolymers
Authors: Halim Andri , Reid Timothy D. , Ren Jing M. , Fu Qiang , Gurr Paul A. , Blencowe Anton , Kentish Sandra E. , Qiao Greg G. 
Published: February 2014

ABSTRACTA series of novel amphiphilic diblock copolymers composed of hydrophilic linear poly(ethylene glycol) (PEG) and linear brush hydrophobic polydimethylsiloxane (PDMS) were synthesized. Three different molecular weights of monomethyl ether PEG were initially functionalized with 2‐bromoisobutyryl bromide to afford macroinitiators suitable for atom‐transfer radical polymerization. The macroinitiators were characterized by gel permeation chromatography, 1H and 13C nuclear magnetic resonance spectroscopic analysis and matrix‐assisted laser desorption ionization time‐of‐flight mass spectroscopy. The three different molecular weight macroinitiators were then chain extended with monomethacryloxypropyl‐terminated PDMS and photoactive 2‐(methylacyloyloxy)ethyl anthracene‐9‐carboxylate in different molar ratios to afford a series of photoresponsive amphiphilic diblock copolymers with high conversions. Self‐assembly of these linear–linear brush diblock copolymers in N,N‐dimethylformamide afforded nanoparticles with hydrodynamic diameters (dH) ranging from 41 to 268 nm, as determined by dynamic light scattering analysis. Crosslinking and stabilization of the nanoparticles was achieved via [4+4] photodimerization of the anthracene moieties upon exposure to UV radiation at 365 nm with the reverse reaction studied at a wavelength of 254 nm. Transmission electron microscopy revealed that the self‐assembled nanoparticles and their crosslinked derivatives had spherical morphologies. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1251–1262
Migration Processes of Metal Elements from Carbon Steel Cylinders to Food Gases
Authors: Tassi Franco , Capecchiacci Francesco , Vaselli Orlando 
Published: February 2014

This study is aimed to provide a protocol for sampling and analysis of metal elements migrating from carbon steel cylinders, used for gas storage and distribution, to food gases, i.e. those gases, such as CO2, N2 and O2, employed by food and beverage industries. The concentrations of 23 selected elements, analysed by inductively coupled plasma mass spectrometry, in the three food gases collected from steel cylinders after a storage period of 50 days, were re‐calculated considering (a) the initial concentrations (i.e. the concentrations of these elements in food gases before being packaged in carbon steel cylinders) and (b) a migration process of 5 years that proceeds in time following a linear trend.Computed data were compared with the limit concentrations for mineral waters (CEE/CEEA/CE no. 83, 03‐11‐1998; D.Lgs no. 3, 2001; D.M. 29‐12‐2003), considering that the quantity of CO2 commonly added to 1 L of mineral water is 5 g. Although no reference values indicating the concentration limits of metal contaminants in food gases are currently promulgated, the results of this comparison have evidenced that the highest concentrations of the most abundant elements among those selected for the test, i.e. Al, Cd, Cr, Cu, Fe, Mn, Ni and Pb, are up to 4 orders of magnitude lower that the previously cited limits. This suggests that the effects of migration of contaminants from carbon steel cylinders do not have a significant influence on the quality of food gases, independently on the type of food gas and carbon steel composition. Copyright © 2014 John Wiley & Sons, Ltd.
What matters in college for retaining aspiring scientists and engineers from underrepresented racial groups
Authors: Chang Mitchell J. , Sharkness Jessica , Hurtado Sylvia , Newman Christopher B. 
Published: February 2014

AbstractThis longitudinal study examined factors that contribute to the persistence of underrepresented racial minority (URM) undergraduates in STEM fields. The primary source of data came from the Cooperative Institutional Research Program's 2004The Freshman Survey(TFS) and 2008College Senior Survey(CSS). The sample included 3,670 students at 217 institutions who indicated on the TFS that they intended to major in a STEM field, 1,634 of whom were underrepresented minority (URM) students. Findings indicate that Black and Latino undergraduates were significantly less likely to persist in STEM majors than were their White and Asian American counterparts. Background characteristics and college experiences moderated this race effect, suggesting both that pre‐college factors may explain some of the observed racial disparities and that individual institutions can take more concrete actions to improve science achievement. Findings from the follow‐up analysis of the sample of URMs suggest that institutions can improve URM STEM persistence by increasing the likelihood that those students will engage in key academic experiences: studying frequently with others, participating in undergraduate research, and involvement in academic clubs or organizations. © 2014 Wiley Periodicals, Inc. J Res Sci Teach 51: 555–580, 2014
Large‐eddy simulations of the Lillgrund wind farm
Authors: Nilsson Karl , Ivanell Stefan , Hansen Kurt S. , Mikkelsen Robert , Sørensen Jens N. , Breton Simon‐Philippe , Henningson Dan 
Published: February 2014

AbstractThe power production of the Lillgrund wind farm is determined numerically using large‐eddy simulations and compared with measurements. In order to simulate realistic atmospheric conditions, pre‐generated turbulence and wind shear are imposed in the computational domain. The atmospheric conditions are determined from data extracted from a met mast, which was erected prior to the establishment of the farm. In order to allocate most of the computational power to the simulations of the wake flow, the turbines are modeled using an actuator disc method where the discs are imposed in the computational domain as body forces which for every time step are calculated from tabulated airfoil data. A study of the influence of imposed upstream ambient turbulence is performed and shows that higher levels of turbulence results in slightly increased total power production and that it is of great importance to include ambient turbulence in the simulations. By introducing ambient atmospheric turbulence, the simulations compare very well with measurements at the studied inflow angles. A final study aiming at increasing the farm production by curtailing the power output of the front row turbines and thus letting more kinetic energy pass downstream is performed. The results, however, show that manipulating only the front row turbines has no positive effect on the farm production, and therefore, more complex curtailment strategies are needed to be tested. Copyright © 2014 John Wiley & Sons, Ltd.
K2S6, a Potassium Polysulfide with Long Sulfur Chain
Authors: Getzschmann Jürgen , Kaskel Stefan 
Published: February 2014

AbstractK2S6 was prepared in high purity and the crystal structure solved from X‐ray powder data. K2S6 represents the most sulfur rich compound in the K‐S‐phase diagram. The dominating species in the crystal structure are six membered sulfur chains in an all‐trans arrangement.