bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano‐ and Mesoscale Structure of Na$_{1 \over 2}$Bi$_{1 \over 2}$TiO3: A TEM Perspective
Authors: Levin Igor , Reaney Ian M. 
Published: May 2012

AbstractThe room‐temperature structure of Na$_{1 \over 2}$Bi$_{1 \over 2}$TiO3 (NBT) ceramics was studied using several transmission electron microscopy (TEM) techniques. High‐angle annular dark field imaging in a scanning TEM confirmed an essentially random distribution of Bi and Na, while electron diffraction revealed significant disorder of the octahedral rotations and cation displacements. Diffraction‐contrast dark‐field and Fourier‐filtered high‐resolution TEM images were used to develop a model that reconciles local and average octahedral tilting in NBT. According to this model, NBT consists of nanoscale twin domains which exhibit a−a−c+ tilting. The coherence length of the in‐phase tilting, however, is limited to a few unit cells and is at least one order of magnitude shorter than that of anti‐phase tilting. Assemblages of such nanodomains are proposed to exhibit an average a−a−c− tilt system. Diffuse sheets of intensity in electron diffraction patterns are attributed to local cation displacements correlated along both 〈111〉 and 〈100〉 chains and suggest partial polar ordering of these displacements. Overall, the TEM data indicate significant chemical, cation‐displacement and tilt disorder of the NBT structure at the nano and mesoscale and support the premise that the Cc symmetry recently proposed from powder diffraction refinements is an averaged “best fit” cell.
A New View of Microcrystalline Silicon: The Role of Plasma Processing in Achieving a Dense and Stable Absorber Material for Photovoltaic Applications
Authors: Bugnon Grégory , Parascandolo Gaetano , Söderström Thomas , Cuony Peter , Despeisse Matthieu , Hänni Simon , Holovský Jakub , Meillaud Fanny , Ballif Christophe 
Published: May 2012

AbstractTo further lower production costs and increase conversion efficiency of thin‐film silicon solar modules, challenges are the deposition of high‐quality microcrystalline silicon (μc‐Si:H) at an increased rate and on textured substrates that guarantee efficient light trapping. A qualitative model that explains how plasma processes act on the properties of μc‐Si:H and on the related solar cell performance is presented, evidencing the growth of two different material phases. The first phase, which gives signature for bulk defect density, can be obtained at high quality over a wide range of plasma process parameters and dominates cell performance on flat substrates. The second phase, which consists of nanoporous 2D regions, typically appears when the material is grown on substrates with inappropriate roughness, and alters or even dominates the electrical performance of the device. The formation of this second material phase is shown to be highly sensitive to deposition conditions and substrate geometry, especially at high deposition rates. This porous material phase is more prone to the incorporation of contaminants present in the plasma during film deposition and is reported to lead to solar cells with instabilities with respect to humidity exposure and post‐deposition oxidation. It is demonstrated how defective zones influence can be mitigated by the choice of suitable plasma processes and silicon sub‐oxide doped layers, for reaching high efficiency stable thin film silicon solar cells.
Microwave‐Assisted Surface Synthesis of a Boron–Carbon–Nitrogen Foam and its Desorption Enthalpy
Authors: Paul Rajib , Voevodin Andrey A. , Zemlyanov Dimitry , Roy Ajit K. , Fisher Timothy S. 
Published: May 2012

AbstractThe modification of microporous carbon foam with boron and nitrogen through a facile microwave chemical treatment are reported. The resulting surfaces of the foam exhibit distinct B–N and carbon domains based on chemical and microscopic analysis, in keeping with theoretical predictions. The resultant materials are shown to exhibit exceptionally high methanol desorption enthalpy and thermal stability in comparison to untreated carbon foam and consequently are suggested as candidate materials for sorption cooling and thermal storage applications using methanol as the adsorbate.
Chemical and Topographical Effects on Cell Differentiation and Matrix Elasticity in a Corneal Stromal Layer Model
Authors: Wilson Samantha L. , Wimpenny Ian , Ahearne Mark , Rauz Saaeha , El Haj Alicia J. , Yang Ying 
Published: May 2012

AbstractControl and maintenance of the keratocyte phenotype is vital to developing in vitro tissue engineered strategies for corneal repair. In this study the influence of topographical and chemical cues on the mechanical, phenotypical and genotypical behaviour of adult human derived corneal stromal (AHDCS) cells in three dimensional (3D) multi‐layered organised constructs is examined. Topographical cues are provided via multiple aligned electrospun nanofiber meshes, which are arranged orthogonally throughout the constructs and are capable of aligning individual cells and permitting cell migration between the layers. The influence of chemical cues is examined using different supplements in culture media. A non‐destructive indentation technique and optical coherence tomography are used to determine the matrix elasiticity (elastic modulus) and dimensional changes, respectively. These measurements were indicative of changes in cell phenotype from contractile fibroblasts to quiescent keratocytes over the duration of the experiment and corroborated by qPCR. Constructs containing nanofibers have a higher initial modulus, reduced contraction and organised cell orientation compared to those without nanofibers. Cell‐seeded constructs cultured in serum‐containing media increased in modulus throughout the culture period and underwent significantly more contraction than constructs cultured in serum‐free and insulin‐containing media. This implies that the growth factors present in serum promote a fibroblast‐like phenotype; qPCR data further validates these observations. These results indicate that the synergistic effect of nanofibers and serum‐free media plus insulin supplementation provide the most suitable topographical and chemical environment for reverting corneal fibroblasts to a keratocyte phenotype in a 3D construct.
Lateral Buckling of High Aspect Ratio Janus Nanowalls
Authors: Yoon Hyunsik , Ghosh Abhijit , Han Jung Yeon , Sung Seung Hyun , Lee Won Bo , Char Kookheon 
Published: May 2012

AbstractIn recent years, the fabrication of Janus materials and their potential applications has been of much interest in Materials Science. Here, we report the fabrication of an entirely novel structure–Janus nanowalls and the phenomenon of lateral buckling in them. Polymeric nanowalls were prepared with the replica molding technique and metal films, of comparable thicknesses, were then deposited on one side of the polymer nanowalls by vacuum process. During the metal deposition, the nanowalls themselves buckle laterally; this buckling is induced by the compressive residual stress in the metal film and geometric confining constraints. The feature of wrinkle patterns resulting from the lateral buckling was theoretically investigated using the scaling analysis. Theoretical results are in good agreement with the experimental observations.
Inorganic Nanoparticles Based Contrast Agents for X‐ray Computed Tomography
Authors: Jakhmola Anshuman , Anton Nicolas , Vandamme Thierry F. 
Published: May 2012

AbstractNanomaterials have gained considerable attention and interest in the development of new and efficient molecular probes for medical diagnosis and imaging. Heavy metal nanoparticles as such are excellent absorber of X‐rays and can offer excellent improvement in medical diagnosis and X‐ray imaging. Substantial progress has been made in the synthesis protocol and characterization studies of these materials but a major challenge still lies in the toxicological studies, which are rather incomplete. The worst known cases were those associated with Thorotrast (suspension of ThO2 nanoparticles) which resulted in many deaths over years. Properly protected nanomaterials conjugated or coated with biocompatible materials can be used for the fabrication of various functional systems with multimodality, targeting properties, reduced toxicity and proper removal from the body. This review aims mainly to provide the advances in the development of inorganic nanoparticle based X‐ray contrasting agents with an overview of methods of their preparation, functionalization and applications in medical diagnosis.
Elastic and Piezoelectric Properties of Zincblende and Wurtzite Crystalline Nanowire Heterostructures
Authors: Boxberg Fredrik , Søndergaard Niels , Xu H. Q. 
Published: May 2012

AbstractThe elastic and piezoelectric properties of zincblende and wurtzite crystalline InAs/InP nanowire heterostructures have been studied using electro‐elastically coupled continuum elasticity theory. A comprehensive comparison of strains, piezoelectric potentials and piezoelectric fields in the two crystal types of nanowire heterostructures is presented. For each crystal type, three different forms of heterostructures—core‐shell, axial superlattice, and quantum dot nanowire heterostructures—are considered. In the studied nanowire heterostructures, the principal strains are found to be insensitive to the change in the crystal structure. However, the shear strains in the zincblende and wurtzite nanowire heterostructures can be very different. All the studied nanowire heterostructures are found to exhibit a piezoelectric field along the nanowire axis. The piezoelectric field is in general much stronger in a wurtzite nanowire heterostructure than in its corresponding zincblende heterostructure. Our results are expected to be particularly important for analyzing and understanding the properties of epitaxially grown nanowire heterostructures and for applications in nanowire electronics, optoelectronics, and biochemical sensing.
Simulation and application of response surface methodology to a nylon‐6 hydrolytic polymerization in a semibatch reactor
Authors: Funai Vanessa Ito , Melo Delba Nisi Cosme , Lima Nádson Murilo Nascimento , Filho Rubens Maciel 
Published: May 2012

AbstractThis work presents an experimental design methodology combined with computational simulation to correlate the influence of operational conditions and reactants charge in the numeric average molecular weight (MWN) as well as on monomer conversion (XCL), for the hydrolytic polymerization of nylon‐6 in a semibatch reactor. It evaluated the reaction temperature, the pressure profile, and the proportion of reactants in the charge. Experimental design was used to screen the most statistically significant variables and to develop a reliable predictive model for each response. The combined use of the models can be applied for process optimization, by establishing MWN and maximum XCL as objective functions. Responses surface allowed the visualization of the responses behavior when changing the independent variables and therefore to identify the optimal tendencies. This work demonstrates that such methodology can be applied for optimization of complex processes like the hydrolytic polymerization of nylon‐6. This polymerization has many side reactions occurring at the same time, which are sensitive to different profiles of pressure and temperature that are applied. This evaluation is quite interesting as such profiles are necessary to perform the several polymerization steps and have a significant impact on product characteristics and therefore in its applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Edible starch sodium octenyl succinate film formation and its physical properties
Authors: Liu Zhaoli , Liu Xiudong , Cao Yafeng , Xie Weiyang , Ma Xiaojun , Yu Xingju 
Published: May 2012

AbstractEdible starch sodium octenyl succinate (SSOS) films, with or without glycerol as plasticizer, were prepared by solution‐casting method. The effect of SSOS concentration, degree of substitution (DS) of octenyl group, as well as glycerol content, on the properties of SSOS films was studied including tensile strength, water vapor permeability (WVP), and oil permeability (OP). The results indicated that the tensile strength of SSOS film was up to 39.4 ± 1.9 MPa when the concentration of SSOS was 0.05 g/mL and DS was 0.05. The increase of glycerol content resulted in a decrease of film tensile strength. WVP of SSOS films was relatively low. Meanwhile, study in OP showed that SSOS films were oilproof. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Toughening of unmodified polyvinylchloride through the addition of nanoparticulate calcium carbonate and titanate coupling agent
Authors: Kemal I. , Whittle A. , Burford R. , Vodenitcharova T. , Hoffman M. 
Published: May 2012

AbstractPVC/CaCO3 polymer nanocomposites of differing compositions were produced using a two‐roll mill and compression molding. In all formulations, 0.6 phr of titanate was incorporated to assist dispersion during processing. The morphology was observed using transmission electron microscopy, and the static and dynamic mechanical and fracture properties were determined. Fracture toughness examination was performed according to strain energy release test method. The presence of nanometer‐sized CaCO3 particles led to a slight decrease in the tensile strength but improved the impact energy absorption, storage modulus, and fracture toughness. The use of titanate coupling agent softened the polymer matrix and reduced the matrix's modulus. Fracture surface examinations by scanning electron microscopy showed that the coupling agent improved particle–matrix bonding and inhibited void formation around the particles. Finite element analysis suggested that the improved particle–matrix bonding reduced the matrix's plasticity around the particles, which decreased the toughening efficiency of the composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Viscosalines B1,2 and E1,2: Challenging New 3‐Alkyl Pyridinium Alkaloids from the Marine Sponge Haliclona viscosa
Authors: Schmidt Gesine , Timm Christoph , Grube Achim , Volk Christian A. , Köck Matthias 
Published: May 2012

AbstractFour new 3‐alkyl pyridinium alkaloids, the viscosalines B1 (1 a), B2 (1 b), E1 (2 a), and E2 (2 b), were isolated from the Arctic sponge Haliclona viscosa. The structure elucidation of these isomeric compounds was challenging due to ambiguous fragments that derive during “standard” mass spectrometric fragmentation experiments. The final structure elucidation relied on the use of a combination of synthesis, liquid chromatography, and mass spectrometry. Three different mass spectrometers were used to differentiate between the synthetic structural isomers: a time‐of‐flight (TOF) mass spectrometer and two ion‐trap mass spectrometers with different ion‐transfer technologies (i.e., skimmer versus funnel optics). Although at first none of the spectrometers returned spectra that permitted structure elucidation, all three mass spectrometers provided analysis that successfully differentiated between the isomers after thorough method optimization. The use of in‐source collision‐induced dissociation (CID) with the ion trap and TOF instrument returned the most interesting results. The mode of fragmentation of the viscosalines under different experimental conditions is described herein. After successful optimization of the mass spectrometric method applied, the chromatographic method was improved to distinguish the previously inseparable isomers. Finally, both the liquid chromatography and mass spectrometric methods were applied to the natural products and the results compared to those from the synthetic compounds.
Surveillance of Invasive Bacterial Pathogens and Human Enteric Viruses in Wastewater Final Effluents and Receiving Water Bodies – a Case Study from Durban, South Africa
Authors: Olaniran Ademola O. , Naidoo Shalinee , Pillay Balakrishna 
Published: May 2012

AbstractThe physico‐chemical characteristics and microbial composition of the final effluents of two municipal wastewater treatment plants in South Africa were assessed between July and September 2009. The impact of the treated final effluents on the receiving water bodies was also evaluated. The temperature across all sampling points ranged between 14 and 22°C, while pH varied from 6.9 to 7.6. High levels of turbidity, chemical oxygen demand (COD), ammonia, nitrate, nitrite and orthophosphate (PO4) were observed in many cases. Turbidity of the samples was in the range of 2.2–288.6 NTU. The concentrations (mg/L) of other physico‐chemical parameters are as follows: COD (9.33–289); ammonia (0.000340–45.4); nitrate (0.062–539); nitrite (0.021–22.6); PO4 (5.3–33.2). The microbial quality of the effluents discharged from the plants did not comply with the limits set by the South African guidelines with respect to pathogens such as Salmonella, Shigella, Escherichia coli, total coliform, faecal coliform, enterococci, faecal streptococci, and viral particles for effluents intended for discharge into receiving watersheds. This study revealed an undesirable impact on the physico‐chemical and microbial qualities of the receiving water bodies as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. This poses a health risk to several rural communities which rely on the receiving water bodies primarily as their sources of domestic water and recreational purposes. There is therefore a need for the intervention of appropriate regulatory agencies in South Africa to ensure compliance of treatment facilities with wastewater effluent quality standards.
Growing Spirodela polyrrhiza in Swine Wastewater for the Production of Animal Feed and Fuel Ethanol: A Pilot Study
Authors: Xu Jiele , Cheng Jay J. , Stomp Anne‐M. 
Published: May 2012

AbstractTo evaluate the performance of Spirodela polyrrhiza grown in swine wastewater for protein and starch production under field conditions, a pilot‐scale duckweed culture pond was installed at Barham Farm, Zebulon, North Carolina and operated from May to November 2010. The anaerobically treated swine wastewater was fed to the duckweed pond intermittently to provide nutrients for the growth of duckweed, and the duckweed biomass was harvested regularly from the pond and prepared as a protein‐ or starch‐rich feedstock for the production of animal feed or fuel ethanol. Over the experimental period, the duckweed pond produced protein and starch at rates of 2.68 and 1.88 g m−2 day−1, respectively. During the same time, NH4–N and o‐PO4–P in the wastewater were, respectively, removed at rates of 92.9 and 2.90 mmol m−2 day−1.
Landfill Leachate Treatment: A Case Study for Istanbul City
Authors: Yaman Cevat , Ozcan Huseyin Kurtulus , Demir Goksel , Okten Hatice Eser , Yildiz Senol , Coban Asli , Balahorli Vahit 
Published: May 2012

AbstractOne of the most important problems arising from landfilling solid wastes is the leachate which contains high amount of pollution. Discharge of leachate without treatment causes negative effects on environmental and public health. In this study, parameters of chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4‐N), and total phosphorus (TP) were examined in the samples taken from the influent and effluent of leachate treatment plant, where Odayeri landfill leachate is treated. Obtained results showed that the treatment plant, which consisted of preanoxic biological treatment system, ultrafiltration (UF) and nanofiltration (NF) units were operating with high efficiency. Among the examined parameters during study, COD, TN, NH4‐N, and TP were found to be treated at the rate of 99, 94.5, 99, and 93.8%, respectively. Landfilling is increasing rapidly in the world and this consequently brings the need of leachate treatment facilities. Therefore, this study is considered to be a guide for construction and operation stages of proposed new treatment plants.
Non‐thermal Effect of Atmospheric‐Pressure RF Cold Plasma on Photocatalytic Activity of As‐deposited TiO2 Film
Authors: Chang Da‐Lei , Li Xiao‐Song , Zhao Tian‐Liang , Yang Jin‐Hua , Zhu Ai‐Min 
Published: May 2012

AbstractTiO2 film is deposited by atmospheric‐pressure (AP), radio‐frequency (RF), dielectric barrier discharge (DBD) plasma at a low power using titanium tetraisopropoxide (TTIP) and O2 as the precursors. The morphology, optical properties, and crystalline structure of the as‐deposited TiO2 film are investigated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet‐visible (UV‐vis) absorption spectroscopy, and Raman spectroscopy. The as‐deposited TiO2 film show high photocatalytic activity in complete oxidation of HCHO to CO2 and degradation of stearic acid. The gas temperature in the RF‐DBD plasma is estimated to be at about 500 K by the rotational temperature via optical emission spectroscopy (OES). The experimental results of amorphous TiO2 film treated by the RF‐DBD plasma further exclude the likelihood of thermal effects derived from the plasma on crystallization of TiO2 film. It is confirmed that the non‐thermal effect of the RF‐DBD plasma on the high photocatalytic activity of the as‐deposited TiO2 film does exist.
The Multiple Ion Channel Blocker CPUY11018 Prevents Aconitine‐Induced Arrhythmias
Authors: Tang Yi‐Qun , Yu Peng , Zhao Na , Yang Qian , Yin Yue‐Miao , Le Xiao‐Yong , Guo Xiang , Wang Min‐Hui , Zhong Hao , You Qi‐Dong 
Published: May 2012

Abstract

Strategy, Management and Health Policy

Enabling Technology, Genomics, Proteomics
Preclinical Research
Preclinical Development Toxicology, Formulation Drug Delivery, Pharmacokinetics
Clinical Development Phases I‐III Regulatory, Quality, Manufacturing
Postmarketing Phase IV

In the present study, the potential antiarrhythmic activities of a new multiple ion channel blocker, CPUY11018 (Y18) were investigated. The effects of Y18 on ICa,L and INa were studied using whole‐cell patch clamp techniques in ventricular muscle cells from normal rats and guinea pigs. The antiarrhythmic effects were tested using a rat model of aconitine‐induced arrhythmias. The effects of Y18 on induction of QT prolongation and torsades de pointes (TdP) were investigated in anesthetized rabbits during stimulation with methoxamine. Y18 produced a concentration‐dependent inhibition of ICa,L and INa in rat ventricular myocytes with IC50 values of 88 μmol/l and 6.5 μmol/l, respectively. In the Y18 treatment group, the development of arrhythmias was significantly delayed. Doses of aconitine that induced ventricular fibrillation were decreased following treatment with 6 mg/kg Y18 (3.8 ± 0.4 μg/100 g vs 6.2 ± 1.3 μg/kg). A significant decrease in the occurrence of atrial fibrillation (100% to 33%; P < 0.05) occurred following Y18 administration. Y18 induction of TdP was significantly less than that seen with dofetilide and azimilide (Az). Thus, Y18 significantly inhibited the production of aconitine‐induced arrhythmias with a low potency for TdP induction. These results suggest that Y18 is a multiple channel blocker with promising antiarrhythmic potential.