bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Model of Thermal‐Fluid Flow in a Radio‐Frequency Plasma Torch
Authors: Ikhlef N. , Leroy O. , Mekideche M. R.
Published: May 2014

The paper aims to clarify the modelling results concerning the heat transfer and fluid flow in a radio‐frequency plasma torch with argon at atmospheric pressure. Fluid numerical simulation requires the coupling of magnetohydrodynamics (MHD) and thermal phenomena. This model combines Navier–Stokes equations with the Maxwell's equations for compressible fluid and electromagnetic phenomena successively. A numerical formulation based on the finite element method is used. In this study, fluid flow and temperature equations are simultaneously solved (direct method, instead of using the indirect method) using a finite elements method (FEM) for optically thin argon plasmas under the assumptions of local thermodynamic equilibrium (LTE) and laminar flow. Appropriate boundary conditions are given, and nonlinear parameters such as the thermal and electrical conductivity of the gas and input power used in the simulation are detailed. We have found that the source of power is located on the torch wall in this type of inductive discharge. The center can be heated by conduction and convection via electromagnetic phenomena (power loss and Lorentz force). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design and evaluation of a multifunctional plate sediment trap suitable for subaqueous and floodplain environments
Authors: Schoelynck Jonas , Oosterlee Lotte , De Groote Toon , Maris Tom , Struyf Eric , Meire Patrick , Temmerman Stijn
Published: May 2014

In recent years, it has become increasingly clear that two‐way interactions between organisms and landscape‐forming processes play a key role in the evolution of many aquatic ecosystems. To be able to compare sedimentation processes among different environments, a standardized method that is generally applicable is necessary. Current methods are usually designed for one environment only or are unreliable in the presence of vegetation. This paper presents the functionality of a plate sediment trap with a lid in combination with a filter paper, which enables the measurement of sedimentation rates in both permanently subaqueous environments and periodically flooded wetlands. We first present the trap design and demonstrate its functionality. No significant differences were found between replicates, nor was there any indication of a trap size effect on the sedimentation rate. Secondly, we demonstrate its applicability in periodically flooded and permanently subaqueous environments and in the presence or absence of vegetation. It is concluded that the use of a standardized method and equipment makes it possible to compare (bio)geomorphological changes in totally different environments. Copyright © 2014 John Wiley & Sons, Ltd.
Primary Amine Attached to an N‐(Carboxyalkyl)imidazolium Cation: A Recyclable Organocatalyst for the Asymmetric Michael Reaction
Authors: Kucherenko Alexandr S. , Lisnyak Vladislav G. , Chizhov Alexandr O. , Zlotin Sergei G.
Published: May 2014

A (1S,2S)‐1,2‐diphenylethane‐1,2‐diamine derivative modified with an N‐(4‐carboxybutyl)imidazolium cation and PF6– anion has been developed and applied as a recyclable organocatalyst of the asymmetric 1,4‐conjugate addition of 4‐hydroxy‐2H‐chromen‐2‐one to 1‐substituted buten‐3‐ones or cyclohexen‐3‐one to afford corresponding Michael adducts in high yields (up to 97 %) and enantioselectivities (up to 90 % ee). The most active (S) enantiomer of the clinically useful anticoagulant warfarin was prepared in this way. The catalyst exhibited better recyclability than its known analog, which does not contain a carboxy group: it could be recycled 5 times in the reaction without a significant decrease in product yield or ee values. Gradual deactivation of the catalyst was caused by leaching during workup rather than by off‐cycle reactions between the catalyst and reagents.
Task structure, need for structure, and creativity
Authors: Rietzschel Eric F. , Slijkhuis J. Marjette , Van Yperen Nico W.
Published: May 2014

Although creativity is often seen as requiring spontaneity and flexibility, recent work suggests that there is creative potential in a structured and systematic approach as well. In a series of four experiments, we show that when Personal Need for Structure (PNS) is high, either chronic (Study 1) or situationally induced (Study 2), creative performance benefits from high task structure. Further, in line with earlier work on cognitive fixation effects, we show that when high task structure contains an example of noncreative task execution, creative performance is impaired, regardless of individuals' PNS. Nevertheless, participants high in PNS react relatively favorably to high task structure (Study 3) and are more likely to adopt a structured task approach when given the choice (Study 4). In sum, our results show that task structure can both stimulate and inhibit creative performance, particularly for people high in need for structure. Copyright © 2014 John Wiley & Sons, Ltd.
When in Rome… Identification and acculturation strategies among minority members moderate the dehumanisation of the majority outgroup
Authors: Miranda Mariana , Gouveia‐Pereira Maria , Vaes Jeroen
Published: May 2014

The study of humanness as a dimension of social judgment has received extensive attention over the past decade. Although the common reported finding is that people attribute more human characteristics to their ingroup than to the outgroup, similar tendencies are expected to be tempered for minority groups when judging the host society. In Study 1, carried out with Gypsy minority members, we tested the hypothesis that those group members who adopt an assimilative strategy identifying more with the host compared with the heritage culture will display the lowest levels of dehumanisation. In Studies 2 and 3, conducted with immigrants in Italy and in Portugal, respectively, the hypothesis was extended from an identification conceptualisation to an acculturation one. Despite significant variability in intergroup settings and measures, results confirmed our hypothesis that immigrants who choose to assimilate with the host culture dehumanise the outgroup less compared with those who adopt any of the other acculturation strategies. Implications for the ethnocentric nature of dehumanisation biases and for intergroup relations in general are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Capillary electrophoresis and herbicide analysis: Present and future perspectives
Authors: Rojano‐Delgado Antonia María , Luque de Castro María D.
Published: May 2014

The aim of this article is to provide an overview on the potential of the CE–herbicides binomial. To this end, the methods proposed so far are discussed: their characteristics, types of samples and analytes to which the methods have been applied, sample preparation steps, if required (e.g. cleanup–preconcentration, derivatization steps), and type of detection in each case. Also, the methods are compared with counterparts based on LC, when appropriate. The role of MS detection in present and future analytical research in this field (both for identification and quantitation) are commented. The foreseeable and desirable trends in analysis of herbicides are also outlined in the light of the present trends in metabolomics as a way of knowing the pathways, the intermediate and final degradation products that can influence the crops and the food chain of humans and other animals, as a result.
Application of a capillary‐assembled microfluidic system for separation of cephalosporins
Authors: Koczka Peter I. , Gaspar Attila
Published: May 2014

This paper demonstrates a simple and easy setting up of a fused‐silica capillary‐assembled microfluidic system (μCE). This system incorporates a split‐flow pressure injection of the sample into a microfluidic system made from PDMS and a short (∼20 cm) length of fused‐silica capillary as a separation unit. The on‐capillary detection was carried out by fiber optic spectrometry. A mixture of six cephalosporin antibiotics was separated in the μCE system and the obtained results were compared to those achievable by conventional CE. The six components could be separated within 8.5 min with the number of theoretical plates around 10 000.
Analytical Expressions of the Concentrations of Substrate, Biomass, and Ethanol for Solid‐State Fermentation in Biofuel Production
Authors: Kirthiga Ondivillu Mothilal , Rajendran Lakshmanan
Published: May 2014

Mathematical and kinetic models are discussed for anaerobic solid‐state fermentation (SSF) in rotating‐drum bioreactors (RDBs). In this study, a simple approximate analytical expression pertaining to the concentration of substrate, biomass, and ethanol is derived in terms of all parameters. These analytical results were found to be in good agreement with numerical solutions (MATLAB/SCILAB) and experimental results.
Gas Analysis of Carbon Oxidation in a Coin‐Type Direct Carbon Fuel Cell
Authors: Lee C. G. , Pak J.
Published: May 2014

Carbon oxidation behaviors were illuminated in terms of gas composition in a coin‐type direct carbon fuel cell. The main gas species in the anode chamber at 850 °C was mostly carbon monoxide, which was generated from the chemical reaction of carbon and molten carbonates. The concentration of CO was reduced as time passed because the reactivity of carbonates was weakened. The open circuit voltage was directly dependent on the CO concentration. The gases in the anode chamber had a vertical concentration distribution; the highest CO and the lowest CO2 concentrations were observed near the electrode. However, the voltage in the polarization state was less dependent on the gas composition. A polarization state of 150 mA cm–2 allowed the oxidation of CO, resulting in an increased CO2 concentration near the electrode. The enlarged CO2 partial pressure facilitated CO generation through the recombination of carbonate ions (CO32–). Decreasing the temperature from 850 to 750 °C reduced the level of carbon monoxide at the anode. The presence of CO as a main component in the anode concludes that the oxidation of solid carbon takes place through the gasification of carbon to CO, then electrochemically to CO2.
Design and Optimization of an Innovative Solid Oxide Fuel Cell–Gas Turbine Hybrid Cycle for Small Scale Distributed Generation
Authors: Facchinetti E. , Favrat D. , Marechal F.
Published: May 2014

Distributed power generation and cogeneration is an attractive way toward a more rational conversion of fuel and biofuel. The fuel cell‐gas turbine hybrid cycles are emerging as the most promising candidates to achieve distributed generation with comparable or higher efficiency than large‐scale power plants. The present contribution is devoted to the design and optimization of an innovative solid oxide fuel cell–gas turbine hybrid cycle for distributed generation at small power scale, typical of residential building applications. A 5 kW planar SOFC module, operating at atmospheric pressure, is integrated with a micro gas turbine unit, including two radial turbines and one radial compressor, based on an inverted Brayton cycle. A thermodynamic optimization approach, coupled with system energy integration, is applied to evaluate several design options. The optimization results indicate the existence of optimal designs achieving exergy efficiency higher than 65%. Sensitivity analyses on the more influential parameters are carried out. The heat exchanger network design is performed for an optimal configuration and a complete system layout is proposed. An example of hybrid system integration in a common residential building is discussed.
Planar High Temperature Heat Pipes for SOFC/SOEC Stack Applications
Authors: Dillig M. , Leimert J. , Karl J.
Published: May 2014

Targeting transient operation of high temperature solid oxide cell (SOC) systems this paper proposes an enhanced heat management mechanism using planar high temperature heat pipes that can be integrated into the SOC‐stack structure. Flat heat pipes with thicknesses down to 4 mm filled with liquid alkali metals for almost isothermal 2D heat spreading, even for intense heat transfer rates, are demonstrated. A new pathway towards a temperature gradient shrinking in SOC‐stacks without using large amounts of additional air‐cooling is shown. The paper will present latest development results on design concepts, size reduced fabrication and filling procedure. An experimental study demonstrates the heat spreading capabilities and power limitations of planar heat spreaders for high temperature applications as in SOEC/SOFC stacks.
Salvage surgery for recurrent carcinoma of the cervical esophagus postesophagectomy
Authors: Chow Velda L. Y. , Chan Jimmy Y. W. , Wei William I.
Published: May 2014

Background

Management of cervical esophageal tumor postesophagectomy is mainly palliative because of inadequate exposure of tumor in the cervicothoracic region. In this study, we propose a means of cure for these patients.

Methods

Between January 2003 and June 2013, 6 patients underwent curative pharyngolaryngectomy and completion cervical esophagectomy via manubrial resection. Operative outcomes were analyzed and compared with a historical cohort who received palliative therapy.

Results

One patient required prolonged hospital stay for pneumonia, resulting in a median hospital stay of 30 days (range, 21–55 days). All patients resumed oral feeding at a mean of 15.2 days (range, 14–19 days). Tracheostoma stenosis was noted in 2 patients. One patient developed nodal recurrence, another with distant metastasis, resulting in a median disease‐free survival of 13 months (range, 4–20 months). Median overall survival was significantly longer than the cohort group (19.0 vs 3.0 months; p = .013).

Conclusion

Salvage surgery in patients with carcinoma of the cervical esophagus postesophagectomy is feasible with significantly prolonged survival. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1170–1175, 2015
Hippocampal slow EEG frequencies during NREM sleep are involved in spatial memory consolidation in humans
Authors: Moroni Fabio , Nobili Lino , Iaria Giuseppe , Sartori Ivana , Marzano Cristina , Tempesta Daniela , Proserpio Paola , Lo Russo Giorgio , Gozzo Francesca , Cipolli Carlo , De Gennaro Luigi , Ferrara Michele
Published: May 2014

The hypothesis that sleep is instrumental in the process of memory consolidation is currently largely accepted. Hippocampal formation is involved in the acquisition of declarative memories and particularly of spatial memories. Nevertheless, although largely investigated in rodents, the relations between spatial memory and hippocampal EEG activity have been scarcely studied in humans. Aimed to evaluate the effects of spatial learning on human hippocampal sleep EEG activity, we recorded hippocampal Stereo‐EEG (SEEG) in a group of refractory epilepsy patients undergoing presurgical clinical evaluation, after a training on a spatial navigation task. We observed that hippocampal high‐delta (2–4 Hz range) activity increases during the first NREM episode after learning compared to the baseline night. Moreover, the amount of hippocampal NREM high‐delta power was correlated with task performance at retest. The effect involved only the hippocampal EEG frequencies inasmuch no differences were observed at the neocortical electrodes and in the traditional polysomnographic measures. The present findings support the crucial role of hippocampal slow EEG frequencies during sleep in the memory consolidation processes. More generally, together with previous results, they suggest that slow frequency rhythms are a fundamental characteristic of human hippocampal EEG during both sleep and wakefulness, and are related to the consolidation of different types of memories. © 2014 Wiley Periodicals, Inc.
Folding of Right‐ and Left‐Handed Three‐Helix Proteins
Authors: Galzitskaya Oxana V. , Pereyaslavets Leonid B. , Glyakina Anna V.
Published: May 2014

We are the first to investigate the relationship between protein handedness and the rate of protein folding. Our findings demonstrate that small three‐helix, left‐handed proteins are less densely packed and should result in faster folding than that of right‐handed, three‐helix proteins. At the same time, right‐handed, three‐helix proteins have higher mechanical stability than the left‐handed proteins. Moreover, from our analysis we have revealed that bacterial three‐helix proteins have some advantages in packing over eukaryotic right‐handed, three‐helix proteins, which should result in faster folding.
Silica Colloidal Membranes with Enantioselective Permeability
Authors: Ignacio‐de Leon Patricia A. , Abelow Alexis E. , Cichelli Julie A. , Zhukov Arkady , Stoikov Ivan I. , Zharov Ilya
Published: May 2014

Robust mesoporous membranes composed of silica spheres were surface‐modified with chiral selector moieties, including small molecules, macrocycles, and polymers. Diffusion rates of enantiomers of a chiral dye through the resulting asymmetrically modified colloidal membranes were measured and the corresponding permselectivities were calculated. The membranes showed enantioselectivities in the range of 1.2–1.8, which were not significantly affected by the structure of the surface‐immobilized chiral electors. This selectivity is on par with most reported polymer‐based solid membranes and bulk liquid membranes. The enantioselectivity results from the surface‐facilitated mechanism of transport of enantiomers through the mesopores.
Stem cell adhesion and proliferation on hydrolyzed poly(butylene succinate)/β‐tricalcium phosphate composites
Authors: Patntirapong Somying , Singhatanadgit Weerachai , Meesap Preeyapan , Theerathanagorn Tharinee , Toso Montree , Janvikul Wanida
Published: May 2014

Although poly(butylene succinate)/β‐tricalcium phosphate (PBSu/TCP) composites are biocompatible and allow the growth and osteogenic differentiation of stem cells, cell attachment and adhesion to the PBSu‐based substrates is often limited. To enhance cell adhesion and proliferation, we used a sodium hydroxide (NaOH) hydrolysis technique to generate a different degree of roughness on PBSu/TCP substrates with different PBSu:TCP ratios. The results showed that NaOH hydrolysis increased surface roughness of PBSu/TCP substrates in a concentration‐dependent manner. Substrates with higher ratios of TCP:PBSu provided more porous topography after NaOH hydrolysis, with a substrate containing 40 wt % TCP (PBSu/TCP‐6040) hydrolyzed with 1.5MNaOH (HPBSu/TCP‐6040‐1.5) showing the highest degree of roughness. As with the roughness, PBSu/TCP surface hydrophilicity was positively affected by the increasing NaOH concentration and TCP incorporation. Stem cells adhered best on HPBSu/TCP‐6040‐1.5 with three‐dimensionally elongated cell extensions. Moreover, the HPBSu/TCP‐6040‐1.5 substrate most significantly facilitated stem cell actin cytoskeleton reorganization and vinculin‐positive focal adhesion formation when compared with the other substrates tested. HPBSu/TCP‐6040‐1.5 also demonstrated the greatest increase in cell proliferation when compared with the other substrates studied. In conclusion, the results have shown that among various substrates tested, HPBSu/TCP‐6040‐1.5 provided the best support for stem cell adhesion and proliferation, suggesting its potential use in bone engineering. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 658–670, 2015.
Structure and function of placental exchange surfaces in goodeid fishes (Teleostei: Atheriniformes)
Authors: Schindler Joachim F.
Published: May 2014

The species of the family Goodeidae have evolved reproductive strategies involving intraovarian gestation, early evacuation of nearly yolk‐exhausted embryos from the ovigerous tissue into the ovarian cavity, placental matrotrophy during intraluminal gestation, and the birth of highly developed fry. The inner ovarian lining becomes hypervascularized during gestational periods and functions as the maternal component of the placental association. Embryotrophic liquid is secreted by the inner ovarian epithelium into the ovarian cavity. Comparative electrophoretic analyses of embryotrophe and maternal blood serum provide evidence for the transfer of maternal serum proteins into the embryotrophe. Trophotaeniae, proctodaeal processes of the embryos, provide a surface for nutrient absorption. Endocytic activity was demonstrated by ingestion of unspecific tracer proteins in various species. Moreover, the trophotaenial absorptive cells (TACs) in Ameca splendens ingest various proteins or random copolymers conjugated to colloidal gold as well as radioiodinated proteins in a way that satisfies the criteria of receptor‐mediated endocytosis. Several aminopeptidases (APs) on the surface of TACs were identified as protein binding sites as evidenced by inhibition of binding and uptake of marker proteins in the presence of AP substrates or AP inhibitors. Morphological adaptations of the embryonic circulatory system pertaining to nutrient and gas exchange were characterized. The embryonic epidermis comprises two layers of squamous cells closely underlain by a dense capillary net. Efficient gas exchange is facilitated by a thin embryotrophe‐blood barrier of both the embryonic skin and the intraovarian lining. J. Morphol. 276:991–1003, 2015. © 2014 Wiley Periodicals, Inc.
Effect of taxoid and nontaxoid site microtubule‐stabilizing agents on axonal transport of mitochondria in untransfected and ECFP‐htau40‐transfected rat cortical neurons in culture
Authors: Das Viswanath , Sim Dalice A. , Miller John H.
Published: May 2014

An important aspect of synaptic plasticity in the brain is axonal transport of essential components such as mitochondria from the soma to the synapse. For uninterrupted transport of cellular cargo down the axon, functional microtubules are required. Altered microtubule dynamics induced by changes in expression of microtubule‐associated tau protein affects normal microtubule function and interferes with axonal transport. Here we investigate the effects of the nontaxoid‐binding‐site microtubule‐stabilizing agents peloruside A (PelA) and laulimalide, compared with the taxoid‐site‐binding agents paclitaxel (Ptx) and ixabepilone, on axonal transport of mitochondria in 1‐day‐old rat pup cerebral cortical neuron cultures. The differences in effects of these two types of compound on mitochondrial trafficking were specifically compared under conditions of excess tau expression. PelA and laulimalide had no adverse effects on their own on mitochondrial transport compared with Ptx and ixabepilone, which inhibited mitochondrial run length at higher concentrations. PelA, like Ptx, was able to partially reverse the blocked mitochondrial transport seen in ECFP‐htau40‐overexpressing neurons, although at higher concentrations of microtubule‐stabilizing agent, the PelA response was improved over the Ptx response. These results support a neuroprotective effect of microtubule stabilization in maintaining axonal transport in neurons overexpressing tau protein and may be beneficial in reducing the severity of neurodegenerative diseases such as Alzheimer's disease. © 2014 Wiley Periodicals, Inc.
Whole‐genome based validation of the adaptive properties of Indian origin probiotic Lactobacillus helveticusMTCC 5463
Authors: Senan Suja , Prajapati Jashbhai B , Joshi Chaitanya G
Published: May 2014

BACKGROUND

The aim of the study was to mine the Lactobacillus helveticus MTCC 5463 genome for genetic determinants to validate its ability to adapt to gut transit stresses and translate functionality to the host.

RESULTS

In silico analysis of the 1 911 350 bp single chromosome of the strain predicted that it had excellent adaptive features like the multisubunit F0F1 ATPase, conjugated bile salt hyrolase, chaperones like hsp33, HtrA, GroEL, GroES, dnaK, grpE, starvation‐inducible proteins and heavy‐metal transporting ATPases. The genome revealed genes for adhesion and aggregation including exopolysaccharides, capsular polysaccharides sortase, elongation factor Tu, aggregation promoting proteins, fibronectin‐binding proteins, S‐layer and mucus‐binding proteins. We could identify genes conferring physiological benefits like immunostimulation, cholesterol reduction, antibacterial and folate production. Thus, through trait and gene matching, the study established that the strain possessed the genetic arsenal required to adapt to the gut milieu. The predictions of functional genes further validate the experimental evidences of adaptation and probiosis.

CONCLUSION

This study provides insight into the feasibility of applying probiogenomics to identify genes that could function as pre‐selection criteria for identification of potential probiotic strains. © 2014 Society of Chemical Industry
Highly selective separation of aminoglycoside antibiotics on a zwitterionic Click TE‐Cys column
Authors: Wei Jie , Shen Aijin , Wan Huihui , Yan Jingyu , Yang Bingcheng , Guo Zhimou , Zhang Feifang , Liang Xinmiao
Published: May 2014

Hydrophilic interaction liquid chromatography has emerged as a valuable alternative approach to ion‐pair chromatography for the separation of aminoglycoside antibiotics in recent years. However, the resolution of structurally related aminoglycosides is a great challenge owing to the limited selectivity. In this work, a cysteine‐based zwitterionic stationary phase (named Click TE‐Cys) was utilized and compared with five commonly used hydrophilic interaction liquid chromatography columns. Click TE‐Cys displayed much better selectivity for structurally similar aminoglycosides. The retention behaviors of aminoglycosides were investigated in detail, revealing that low pH (2.7 or 3.0) and high buffer concentration (≥50 mM) were preferable for achieving good peak shape and selectivity. Effective resolution of ten aminoglycosides including spectinomycin, dihydrostreptomycin, streptomycin, gentamicin C1, gentamicin C2/C2a, gentamicin C1a, kanamycin, paromonycin, tobramycin, and neomycin was realized at optimized conditions. Additionally, spectinomycin and its related impurities were successfully resolved. The results indicated the great potential of the Click TE‐Cys column in the separation of aminoglycoside mixtures and related impurities.
Separation of phenylsuccinic acid enantiomers using biphasic chiral recognition high‐speed countercurrent chromatography
Authors: Sun Genlin , Tang Kewen , Zhang Panliang , Yang Weijun , Sui Guoqing
Published: May 2014

High‐speed countercurrent chromatography (HSCCC) combined with biphasic chiral recognition was successfully applied to the resolution of phenylsuccinic acid enantiomers. d‐Isobutyl tartrate and hydroxypropyl‐β‐cyclodextrin were employed as lipophilic and hydrophilic selectors dissolved in the organic stationary phase and aqueous mobile phase, respectively. The two‐phase solvent system was made up of n‐hexane/methyl tert‐butyl ether/water (0.5:1.5:2, v/v/v). Impacts of the type and concentration of chiral selectors, the pH value of the aqueous phase solution as well as the temperature on the separation efficiency were investigated. By means of preparative HSCCC, pure enantiomer was obtained by separating 810 mg of racemate with a purity >99.5% and a recovery rate between 82 and 85%. The experimental results indicate that biphasic recognition HSCCC provide a promising means for efficient separation of racemates.
Synthesis, Cellular Uptake, and Biodistribution of Whey‐Rich Nanoparticles
Authors: Zhen Xu , Wang Xin , Yang Chenchen , Liu Qin , Wu Wei , Liu Baorui , Jiang Xiqun
Published: May 2014

Whey‐poly(acrylic acid) (whey‐PAA) nanoparticles are prepared by polymerizing acrylic acid (AA) monomer in the presence of whey protein in a complete aqueous medium. The properties, drug loading, and release as well as in vitro cytotoxicity of whey‐PAA nanoparticles are examined. The cellular uptakes and penetration of nanoparticle in the SH‐SY5Y monolayer cells and multicellular tumor spheroids are observed. The in vivo distribution of the nanoparticles in tumor‐bearing mice is evaluated. Confocal laser scanning microscopy and co‐localization images show that the nanoparticles are well internalized by the cells through the endocytosis mechanism. Drug‐loaded whey‐PAA nanoparticles can penetrate multicellular tumor spheroids more deeply. In vivo near‐infrared fluorescence imaging examination and in vivo DOX distribution show that the drug‐loaded whey‐PAA nanoparticles can well accumulated in the tumor site. Thus, these whey‐rich nanoparticles seem to be very promising drug carriers for drug delivery.
Efficient Gene Carriers Composed of 2‐Hydroxypropyl‐β‐Cyclodextrin, Ethanolamine‐Functionalized Poly(glycidyl methacrylate), and Poly((2‐dimethyl amino)ethyl methacrylate) by Combination of ATRP and Click Chemistry
Authors: Zhu Yun , Zheng Xuefeng , Yu Bingran , Yang Wantai , Zhao Nana , Xu Fujian
Published: May 2014

In this work, a simple one‐step method is first employed to produce the bromoisobutyryl‐terminated 2‐hydroxypropyl‐β‐cyclodextrin (HPCD‐Br). The pendant epoxy groups of poly(glycidyl methacrylate) block prepared via ATRP from HPCD‐Br can be reacted with ethanolamine to produce HPCD‐PGEA which exhibits much lower cytotoxicity and better gene transfection yield than polyethylenimine (25 kDa) in COS7 and HepG2 cell lines. Moreover, poly((2‐dimethyl amino)ethyl methacrylate) blocks can be incorporated into low‐molecular‐weight HPCD‐PGEA via “click” reaction to further enhance the gene transfection efficiency in HepG2 cell lines.
Structure and mechanical properties of ZnAl40Cu3 alloy modified with rare earth elements
Authors: Michalik R.
Published: May 2014

The influence of modification of rare earth elements on the structure and mechanical properties of ZnAl40Cu3 alloy is presented in this paper. The ZnAl40Cu3, ZnAl40Cu3SiM and ZnAl40Cu3Si (modified alloy) alloys were tested. The ZnAl40Cu3Si and ZnAl40Cu3 alloys were characterized and revealed a heterogeneous, fine‐grained, dendritic structure. The structure of the alloy ZnAl40Cu3SiM was much more homogeneous. It was found that the addition of silicon reduces the tensile strength. Addition of rare earth elements (REE) to the alloy with silicon resulted in the re‐growth of strength. It was also found that the modification of rare earth elements increases the hardness of the alloy.
Calculation of effective Young's modulus distribution from electron backscatter diffraction results for stochastic analyses in aerospace applications
Authors: Dresbach C. , Dressler U. , Gussone J. , Reh S.
Published: May 2014

In reliability analyses of safety‐relevant components it is necessary to consider the variations in load, geometry and material properties. The scatter in load, geometry and global material properties is nowadays addressed in some stochastic analyses [, ], whereas the scatter in local material properties is not adequately regarded due to difficulties in determining meaningful and stochastically relevant local material properties. In this paper a method for estimating the local distribution of the effective elastic behavior, belonging to a defined component direction, is presented. First, electron backscatter diffraction (EBSD) analyses of relevant cross sections were performed. Second, the effective elastic behavior perpendicular to the cross section was calculated for each scan point from the determined Euler angles. By using direct tensor rotation and generalized Hooke's law, the method can be applied to all kind of crystal structures if the elastic constants of the single crystal material are known.

The experimental procedure, the mathematical background und the numerical realization are described in detail. Two examples of applying the procedure to materials for aerospace components as well as a stochastic finite element simulation considering the determined scatter of the elastic properties are shown.
Lateral collapse of short‐length sandwich tubes compressed by different indenters and exposed to external constraints
Authors: Baroutaji A. , Olabi A. G.
Published: May 2014

In this paper, sandwich tube components which consist of thin‐walled circular tubes with aluminium foam core are proposed as energy absorption systems. The sandwich tubes were laterally crushed under quasi‐static loading conditions. The sandwich tubes were crushed under two types of indenters and exposed to three different types of external constraints. The collapsing behaviour and the energy absorption responses of these systems were investigated by nonlinear finite element analysis through ANSYS‐LS‐DYNA. Various indicators which describe the effectiveness of energy absorbing systems were used as a marker to compare the various systems. It was found that the sandwich tube systems compressed by cylindrical indenters particularly the unconstrained system and the system with inclined constraints offered a very desirable force‐deflection in which the force is almost constant in the post collapse stage. The employing of external constraints was noticed as a feasible method of increasing the SEA particularly when cylindrical indenter is used.
Simulation of fracture/breakup of concrete magazine using cohesive element
Authors: Fan S. C. , Yu Q. J. , Lee C. K.
Published: May 2014

To determine the potential hazard zone around an ammunition storage magazine is the research interest of many researchers working on explosive safety. Carrying out an explosion test of an ammunition storage magazine is expensive. As such, numerical modeling offers an economical solution to supplement the field tests, and it has been widely used to simulate the magazine breakup. In the literature and own previous studies, numerical simulations often resorted to the Lagrangian finite‐element method and used the nodal‐split algorithm to model the concrete fracture/breakup upon internal detonation. Pitfalls in that approach have not been fully recognized [–]. In it, all elements initially connected to the same node would be spilt in all directions once the nodal strain reached the threshold. This strain‐based splitting criterion lacks of sound physical meaning. To overcome those pitfalls, the present study adopts a kind of interface element, namely a cohesive element, to simulate the fracture/breakup. Strain rate dependent experiments were carried out to obtain the fracture criteria, which were then applied to define the threshold for element‐face split. Results show that it yields good agreement with experiment tests, including Split Hopkinson Pressure Bar (SHPB) on concrete specimen and breakup of concrete magazine upon detonation.
Laser drilling of hollow sphere structures
Authors: Riegel H. , Merkel M. , Öchsner A.
Published: May 2014

A special composite and cellular material – the metallic hollow sphere structure (MHSS) – represents an advanced material. The core element of the structure is a hollow sphere with a wall out of porous steel. This shell allows a high geometric reproducibility. It is an interesting base material for lightweight design. However, processing technologies for further manufacturing of metallic hollow sphere structure are necessary. Laser beam drilling is a highly efficient technique with heat input concentrated locally at the structure. Laser drilling is applied to metallic hollow sphere structures. The influence of different geometries and joining technologies of the spheres on the drilling behaviour is investigated.

Percussion drilling is used to form holes with a CO2‐laser into the metallic hollow sphere structure. The investigated mean laser power is 400 W. Two different focal lenses with focal lengths of 5″ and 7.5″ allow investigations with different focal diameters and Rayleigh lengths. Diameter and roundness of the laser drilled holes are measured in five layers of different drill depths z. The maximum drilled depth is about 40 mm with a 5″ lense and about 50 mm with the f = 7.5″ lens. The relative roundness is determined and decreases with increasing drill depth. The diameter d(z) as a function of the drill depth follows the shape of an isophote, a line of constant intensity inside the laser beam. The brazed hollow sphere structures have considerably less drill depth than the sintered.
Simulation and experimental validation of acoustic properties of hollow sphere structures
Authors: Janousch C. , Winkler R. , Wiegmann A. , Pannert W. , Merkel M. , Öchsner A.
Published: May 2014

Customers nowadays regard the noise and vibration behavior as an essential product property. Cellular character materials, in particular hollow sphere structures, are predestined to absorb sound in a very efficient manner due to their cellular character. Depending on the constituent material, the geometric parameters like the diameter of the spheres, the thickness of the walls and the assembling schema of single spheres, the absorption coefficient can be reduced to very low levels. In contrast to other cellular materials, the frequency and bandwidth can actively be influenced by the variation of the above mentioned parameters.

In order to predict the acoustic behavior of a structure, FE or CFD analyses are used as standard tools. In addition, there exist some parameter based models, e.g. the BIOT theory, which characterizes the absorption, transmission and reflection coefficients using a few macroscopic parameters.

Within this contribution, the acoustic properties of hollow sphere structures are investigated by a so‐called virtual material laboratory GeoDict (by Math2Market GmbH, originally by the Fraunhofer Institute for Industrial Mathematics). The results for the absorption and reflection coefficients are compared to those gained by classical analysis methods and experiments based on Kundt's tube.
Analysis of particle methods for structured population models with nonlocal boundary term in the framework of bounded Lipschitz distance
Authors: Gwiazda Piotr , Jabłoński Jędrzej , Marciniak‐Czochra Anna , Ulikowska Agnieszka
Published: May 2014

Recently developed theoretical framework for analysis of structured population dynamics in the spaces of nonnegative Radon measures with a suitable metric provides a rigorous tool to study numerical schemes based on particle methods. The approach is based on the idea of tracing growth and transport of measures which approximate the solution of original partial differential equation. In this article, we present analytical and numerical study of two versions of Escalator Boxcar Train algorithm which has been widely applied in theoretical biology, and compare it to the recently developed split‐up algorithm. The novelty of this article is in showing well‐posedness and convergence rates of the schemes using the concept of semiflows on metric spaces. Theoretical results are validated by numerical simulations of test cases, in which distances between simulated and exact solutions are computed using flat metric. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1797–1820, 2014
Streamline diffusion finite element method for stationary incompressible magnetohydrodynamics
Authors: Zhang Guo‐Dong , He Yinnian , Zhang Yan
Published: May 2014

In this article, a streamline diffusion finite element method is proposed and analyzed for stationary incompressible magnetohydrodynamics (MHD) equations. This method is stable for any combinations of velocity, pressure, and magnet finite element spaces, without requiring Ladyzenskaja‐Babuška‐Brezzi (LBB) condition. The well‐posedness and convergence (at optimal error rate) of this scheme are proved in terms of some conditions. Two numerical experiments are illustrated to validate our theoretical analysis and show the streamline diffusion finite element approach is effective for solving the MHD problems. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1877–1901, 2014
Reversible hyperphagia and obesity in rats with gastric bypass by central MC3/4R blockade
Authors: Mumphrey Michael B. , Hao Zheng , Townsend R. Leigh , Patterson Laurel M , Morrison Christopher D. , Münzberg Heike , Stylopoulos Nicholas , Ye Jianping , Berthoud Hans‐Rudolf
Published: May 2014

Objective

To test the commonly held assumption that gastric bypass surgery lowers body weight because it limits the ability to eat large amounts of food.

Methods

Central melanocortin signaling was blocked by ICV infusion of the melanocortin‐3/4 receptor antagonist SHU9119 for 14 days in rats whose high‐fat diet‐induced obesity had been reversed by Roux‐en‐Y gastric bypass surgery.

Results

SHU9119 increased daily food intake (+ 100%), body weight (+30%), and fat mass (+50%) in rats with RYGB, surpassing the presurgical body weight and that of saline‐treated sham‐operated rats. Doubling of food intake was entirely due to increased meal frequency, but not meal size. After termination of SHU9119, body weight promptly returned to near preinfusion levels. In sham‐operated rats, SHU9119 produced even larger increases in food intake and body weight.

Conclusions

RYGB rats do not settle at a lower level of body weight because they cannot eat more food as they can easily double food intake by increasing meal frequency. The reversible obesity suggests that RYGB rats actively defend the lower body weight. However, because both RYGB and sham‐operated rats responded to SHU9119, central melanocortin signaling is not the critical mechanism in RYGB rats responsible for this defense.
Varicella zoster immune status in children treated for acute leukemia
Authors: Patel Soonie R. , Bate Jessica , Maple Peter A.C. , Brown Kevin , Breuer Judith , Heath Paul T.
Published: May 2014

Children treated for acute leukemia are at increased risk of severe infection with varicella zoster virus (VZV). We studied the VZV sero‐status of children with acute leukemia prior to starting chemotherapy and after completion of chemotherapy. VZV sero‐status was assessed using time resolved fluorescence immunoassay (TRFIA) before starting treatment and 6 months after completion of treatment. Prior to starting treatment for acute leukemia, a significant proportion of children (35%) are VZV seronegative. On completion of treatment most patients maintained protective VZV antibody levels; however, 35% had reduced/loss VZV antibody to a level considered non‐protective and susceptible to VZV infection. Pediatr Blood Cancer 2014;61:2077–2079. © 2014 Wiley Periodicals, Inc.
Controllable preparation and heavy‐metal‐ion adsorption of lignosulfonate‐polypyrrole composite nanosorbent
Authors: Luo Jia‐Jia , Lü Qiu‐Feng
Published: May 2014

Lignosulfonate‐polypyrrole (LS‐PPY) composite nanospheres were prepared facilely via an in situ polymerization of pyrrole monomers in the presence of lignosulfonate as a dispersant and ammonium persulfate as an oxidant. The LS‐PPY composite was characterized with Fourier Transform infrared spectroscopy (FTIR), thermogravimetric analysis, wide‐angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), field‐emission SEM, and transmission electron microscopy. Uniform LS‐PPY solid composite nanospheres with an average diameter of 154 nm were obtained. The LS‐PPY composite nanospheres were applied to adsorption of Ag(I) and Pb(II) ions from aqueous solutions. Maximum adsorption capacities of Ag(I) and Pb(II) were up to 759.3 mg g−1 and 207.5 mg g−1, respectively. Furthermore, the silver ions can be reduced to metallic silver nanowires through a redox reaction between the LS‐PPY composite nanospheres and the silver ions. A productive no‐template route to fabrication of LS‐PPY composite nanospheres with controllable size and heavy‐metal‐ion adsorption ability was achieved. POLYM. COMPOS., 36:1546–1556, 2015. © 2014 Society of Plastics Engineers
Low‐dose aspirin for prevention of adverse outcomes related to abnormal placentation
Authors: Bujold Emmanuel , Roberge Stéphanie , Nicolaides Kypros H.
Published: May 2014

Meta‐analysis of randomized studies on the use of low‐dose aspirin in women at high risk of preeclampsia (PE) has demonstrated that if treatment is initiated at ≤16 weeks' gestation, there is significant reduction in the risk of PE [relative risk (RR) 0.47, 95% confidence interval (CI) 0.36–0.62], fetal growth restriction (RR 0.46, 95% CI 0.33–0.64), preterm birth (RR 0.35, 95% CI 0.22–0.57) and perinatal death (RR 0.41, 95% CI 0.19–0.92), whereas the effect of treatment after 16 weeks is substantially less (RR 0.78, 95% CI 0.61–0.99; RR 0.98, 95% CI 0.88–1.08; RR 0.90, 95% CI 0.83–0.97; and RR 0.93, 95% CI 0.73–1.19, respectively). Moreover, the decrease in the risk of PE from early onset treatment seems to be related to the dose of aspirin, and a dose of >80 mg daily should be considered for optimal benefits. © 2014 John Wiley & Sons, Ltd.
Large scale conformational transitions in β‐structural motif of gramicidin A: kinetic analysis based on CD and FT‐IR data
Authors: Sychev Sergei V. , Ivanov Vadim T.
Published: May 2014

Gramicidin A (gA) is a polypeptide antibiotic, which forms dimeric channels specific for monovalent cations in artificial and biological membranes. It is a polymorphic molecule that adopts a unique variety of helical conformations, including antiparallel double‐stranded ↑↓β5.6 or ↑↓β7.2 helices (number of residues per turn) and a single‐stranded β6.3 helix (the ‘channel form’). The behavior of gA‐Cs+ complex in the micelles of TX‐100 was studied in this work. Transfer of the complex into the micelles activates a cascade of sequential conformational transitions monitored by CD and FT‐IR spectroscopy:
urn:x-wiley:10752617:media:psc2643:psc2643-math-0001At the first step after Cs+ removal, the RH ↑↓β5.6 helix is formed, which has been discussed so far only hypothetically. Kinetics of the transitions was measured, and the activation parameters were determined. The activation energies of the ↑↓β5.6 → β‐helical monomer transition in dioxane and dioxane/water solutions were also measured for comparison. The presence of water raises the transition rate constant ~103 times but does not lead to crucial fall of the activation energy. All activation energies were found in the 20–25 kcal/mol range, i.e. much lower than would be expected for unwinding of the double helix (when 28 H‐bonds are broken simultaneously). These results can be accounted for in the light of local unfolding (or ‘cracking’) model for large scale conformational transitions developed by the P. G.Wolynes team [Miyashita O, Onuchic JN, Wolynes PG. Proc. Natl. Acad. Sci. USA 2003; 100: 12570‐12575.]. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Formation of ordered array of core/shell ZnS/Ge/ZnS nanostructures by thermal evaporation method
Authors: Beltiukov A. , Valeev R. , Romanov E. , Mukhgalin V.
Published: May 2014

This paper reports the results of studies of ZnS/Ge/ZnS nanostructures, obtained by high vacuum thermal deposition of ZnS and Ge powders into porous anodic aluminium oxide (AAO) with different diameters of pores. Scanning electron microscopy (SEM) investigations reveal two types of nanostructures having the form of rings (sample with diameter of pores 70 nm) and rods (samples with diameter of pores 80 and 110 nm). It is also shown that the other porosity parameters such as interporous distances affect the formation of a particular type of nanostructures. X‐ray and electron diffraction study show two phases, ZnS and Ge. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Seasonal variation of performance in concentrator photovoltaic system
Authors: Nomura Kei , Ota Yasuyuki , Minemoto Takashi , Nishioka Kensuke
Published: May 2014

Concentrator Photovoltaic (CPV) system was installed in the University of Miyazaki, Japan. The system's output parameters and meteorological condition experienced by the system i.e. incident irradiance, incident spectrum distribution, and cell temperature were recorded. A statistical analysis method was proposed so that the influences of spectrum distribution variations and cell temperature on the output performance of the system can be observed separately. It was found that the performance of the CPV system significantly depended on the variation of the incident solar spectrum distribution rather than cell temperature. Using this method, the performance of CPV system was analysed throughout the seasons. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)