bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autoadhesion of Glassy Polymers
Authors: Boiko Yuri M. 
Published: July 2012

AbstractSummary: Thick bulk films of linear amorphous polymers with different chain architecture and molecular weight were brought into contact with themselves in a lap‐shear joint geometry at bonding temperatures (T) below the glass transition temperatures of their bulk (T), at a small contact pressure, in order to form autoadhesive joints. As‐bonded joints were shear‐fractured in tension at ambient temperature, and their lap‐shear strength was measured as a function of T, bonding time and molecular weight. The kinetics of the process of the development of the lap‐shear strength at T < T was investigated, and the molecular mechanisms governing this process were discussed. The quasi‐equilibrium surface glass transition temperatures of the investigated polymers were estimated and compared with the corresponding values of T.
Decreased systemic IGF‐1 in response to calorie restriction modulates murine tumor cell growth, nuclear factor‐κB activation, and inflammation‐related gene expression
Authors: Harvey Alison E. , Lashinger Laura M. , Otto Glen , Nunez Nomeli P. , Hursting Stephen D. 
Published: July 2012

AbstractCalorie restriction (CR) prevents obesity and has potent anticancer effects associated with altered hormones and cytokines. We tested the hypothesis that CR inhibits MC38 mouse colon tumor cell growth through modulation of hormone‐stimulated nuclear factor (NF)‐κB activation and protumorigenic gene expression. Female C57BL/6 mice were randomized (n = 30/group) to receive control diet or 30% CR diet. At 20 wk, 15 mice/group were killed for body composition analysis. At 21 wk, serum was obtained for hormone analysis. At 22 wk, mice were injected with MC38 cells; tumor growth was monitored for 24 d. Gene expression in excised tumors and MC38 cells was analyzed using real‐time RT‐PCR. In vitro MC38 NF‐κB activation (by p65 ELISA and immunofluorescence) were measured in response to varying IGF‐1 concentrations (1–400 ng/mL). Relative to controls, CR mice had decreased tumor volume, body weight, body fat, serum IGF‐1, serum leptin, and serum insulin, and increased serum adiponectin (P < 0.05, each). Tumors from CR mice, versus controls, had downregulated inflammation‐ and/or cancer‐related gene expression, including interleukin (IL)‐6, IL‐1β, tumor necrosis factor‐α, cyclooxygenase‐2, chemokine (C–C motif) ligand‐2, S100A9, and F4/80, and upregulated 15‐hydroxyprostaglandin dehydrogenase expression. In MC38 cells in vitro, IGF‐1 increased NF‐κB activation and NF‐κB downstream gene expression (P < 0.05, each). We conclude that CR, in association with reduced systemic IGF‐1, modulates MC38 tumor growth, NF‐κB activation, and inflammation‐related gene expression. Thus, IGF‐1 and/or NF‐κB inhibition may pharmacologically mimic the anticancer effects of CR to break the obesity–colon cancer link. © 2012 Wiley Periodicals, Inc.
Reversible generalized dystonia and encephalopathy from thiamine transporter 2 deficiency
Authors: Serrano Mercedes , Rebollo Mónica , Depienne Christel , Rastetter Agnès , Fernández‐Álvarez Emilio , Muchart Jordi , Martorell Loreto , Artuch Rafael , Obeso José A. , Pérez‐Dueñas Belén 
Published: July 2012

AbstractBackground:Thiamine transporter‐2 deficiency, a condition resulting from mutations in the SLC19A3 gene, has been described in patients with subacute dystonia and striatal necrosis. The condition responds extremely well to treatment with biotin and has thus been named biotin‐responsive basal ganglia disease. Recently, this deficiency has also been related to Wernicke's‐like encephalopathy and atypical infantile spasms, showing heterogeneous responses to biotin and/or thiamine.Methods:Two Spanish siblings with a biotin‐responsive basal ganglia disease phenotype and mutations in SLC19A3 presented with acute episodes of generalized dystonia, rigidity, and symmetrical lesions involving the striatum, midline nuclei of the thalami, and the cortex of cerebral hemispheres as shown by magnetic resonance imaging.Results:The clinical features resolved rapidly after thiamine administration.Conclusions:Despite the rarity of thiamine transporter–2 deficiency, it should be suspected in patients with acute dystonia and basal ganglia injury, as thiamine can halt disease evolution and prevent further episodes. © 2012 Movement Disorder Society
Increased vessel depiction of the carotid bifurcation with a specialized 16‐channel phased array coil at 3T
Authors: Tate Quinn , Kim Seong‐Eun , Treiman Gerald , Parker Dennis L. , Hadley J. Rock 
Published: July 2012

AbstractThe purpose of this work was to design and construct a multichannel receive‐only radiofrequency coil for 3T magnetic resonance imaging of the human carotid artery and bifurcation with optimized signal‐to‐noise ratio (SNR) in the carotid vessels along the full extent of the neck. A neck phantom designed to match the anatomy of a subject with a neck representing the body habitus often seen in subjects with carotid arterial disease was constructed. Sixteen circular coil elements were arranged on a semirigid fiberglass former that closely fit the shape of the phantom, resulting in a 16‐channel bilateral phased array coil. Comparisons were made between this coil and a typical 4‐channel carotid coil in a study of 10 carotid vessels in five healthy volunteers. The 16‐channel carotid coil showed a 73% average improvement in SNR at the carotid bifurcation. This coil also maintained an SNR greater than the peak SNR of the 4‐channel coil over a vessel length of 10 cm. The resulting increase in SNR improved vessel depiction of the carotid arteries over an extended field of view, and demonstrated better image quality for higher parallel imaging reduction factors compared to the 4‐channel coil. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
In vitro and in vivo studies of 17O NMR sensitivity at 9.4 and 16.4 T
Authors: Lu Ming , Zhang Yi , Ugurbil Kamil , Chen Wei , Zhu Xiao‐Hong 
Published: July 2012

AbstractIn vivo 17O magnetic resonance spectroscopy has been successfully applied for imaging the cerebral metabolic rate of oxygen consumption through the detection of metabolically produced H217O from the inhaled 17O‐labeled oxygen in animals at high field. In this study, we compared the 17O sensitivity for detecting natural abundance H217O signals from a phantom solution and rat brains at 9.4 and 16.4 T. The 17O signal‐to‐noise ratio measured at 16.4 T was 2.9‐ and 2.7–2.8‐fold higher than that at 9.4 T for the phantom and rat brain studies, respectively. Similarly, three‐dimensional 17O magnetic resonance spectroscopy imaging data showed a more than 2.7‐fold higher signal‐to‐noise ratio in the central rat brain region at 16.4 T than that at 9.4 T. The substantial 17O signal‐to‐noise ratio gain at ultrahigh field significantly improved the reliability for imaging the cerebral metabolic rate of oxygen consumption and will provide an opportunity for in vivo assessment of altered oxidative metabolism associated with brain functions and neurological diseases. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
New petroleum absorbers based on cardanol‐furfuraldehyde magnetic nanocomposites
Authors: Varela A. , Oliveira G. , Souza F.G. , Rodrigues C.H.M. , Costa M.A.S. 
Published: July 2012

AbstractCardanol‐furfuraldehyde/maghemite composites were prepared through a bulk polymerization aiming to produce magnetic green resins able to absorb petroleum spilled on the water. Several techniques such as Fourier transform infrared spectroscopy, ultraviolet–visible spectrophotometry, wide angle X‐ray scattering, and small angle X‐ray scattering were used in the characterization of the materials. In addition, magnetic force and oil removal capability tests were also performed. Obtained materials presented a good magnetic force allied with a considerable oil removal capability: each gram of the resin was able to remove 10g of petroleum from the water. Therefore, the easy and simple production process presented is a promising tool for oil spill cleanup process. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Comparison of flocculated and dispersed single‐wall carbon nanotube‐based coatings using nonionic surfactants
Authors: Prichard Todd D. , Vogt Bryan D. 
Published: July 2012

AbstractSingle‐wall carbon nanotubes (SWNTs) are promising filler materials for advanced polymer composites, but the impressive properties that have been predicted theoretically have not been realized experimentally. This gap is generally attributed to aggregation and nonideal dispersion of the SWNTs. Here, nonionic surfactants based on poly(ethylene oxide) are used to disperse SWNTs in either water or ethanol using sonication. The dispersed aqueous SWNTs are stable, while the analogous ethanol system yields loosely flocculated SWNTs. After drying these dispersions, the electrical conductivity of the flocculated system is at least an order of magnitude greater than the dispersed system at the same SWNT loading with conductivity greater than 20 S/cm obtained for the flocculated systems containing unsorted, commercial SWNTs. These flocculated systems can be readily sprayed to create conductive coatings. Despite their high electrical conductivity, these coatings provide only modest electromagnetic interference shielding (<20 dB) when testing large areas (30.5 × 30.5 cm2), which suggests significant heterogeneity or defects in these coatings that are not readily visible by eye or scanning electron microscopy. This defect mechanism is consistent with a decrease in shield efficacy at high SWNT loadings, despite no statistical change in the electrical conductivity of the coating. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
High‐density polyethylene nanocomposites using masterbatches of chlorinated polyethylene/graphene oxide
Authors: Chaudhry A.U. , Mittal Vikas 
Published: July 2012

AbstractGraphene‐based nanocomposites were generated by solution mixing of the graphene oxide filler with chlorinated polyethylene compatibilizers followed by melt mixing of the solution mixed masterbatches with high‐density polyethylene. Compatibilizers with two different chlorination contents were used in different amounts in order to analyze their effect on the morphology and properties of resulting nanocomposites. Peak melting point as well as overall crystallinity was affected by graphene oxide as well as compatibilizers. Compatibilizer with higher chlorination content also interacted with polar graphene oxide surface more effectively thus leading to better filler dispersion in the composites. The addition of compatibilizers to the composites resulted in their shear and processing stability at higher angular frequencies and temperature, which otherwise was not possible for pure polymer as well as composites without compatibilizer. The mechanical performance of the nanocomposites at ambient conditions was also affected by the factors like filler delamination, plasticization of the matrix, compatibilizer content as well as their chlorination level and amorphous/semicrystalline nature. An increase of 16% in tensile modulus and 21% in strength of the composites with 5 wt% of 25% chlorinated compatibilizer at 0.5 wt% graphene oxide content was observed. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Continuous polymerization of methyl methacrylate in a taylor‐couette reactor. I. Influence of fluid dynamics on monomer conversion
Authors: Liu Zhen , Jin Tao , Kind Matthias 
Published: July 2012

AbstractA Taylor‐Couette reactor offers certain advantages for continuous polymerization over other reactor types. These advantages are its rather narrow residence time distribution (series of vortices) and its good heat transfer characteristics. Hydrodynamics in this type of reactor can be controlled by its geometry (diameter, gap, width, length) and its operational parameters (rotational speed, mean residence time, viscosity). In this article, a model is presented which is suited to answer the question of how hydrodynamics influences the productivity of a continuously operated Taylor‐Couette polymerization reactor. To this end, productivity is quantified by the rate of monomer conversion. The model is specified and experimentally validated for the free radical polymerization of methyl methacrylate with the solvent xylene and 2,2‐azoisobutyronitrile as the initiator. The model considers the following four phenomena: (i) Macromixing between the vortex cells is accounted for by an axial dispersion model. (ii) The dependence of viscosity on monomer conversion along the reactor is described by a viscosity model. (iii) Polymerization kinetics and its dependence on hydrodynamics are correlated from experimental data. (iv) The dependence of segregation index Is on the local energy dissipation is used to characterize micromixing within the vortices. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
A Novel Application of Plasmonics: Plasmon‐Driven Surface‐Catalyzed Reactions
Authors: Sun Mengtao , Xu Hongxing 
Published: July 2012

AbstractThe first experimental and theoretical evidence of the surface‐catalyzed reaction of p,p′‐dimercaptoazobenzene (DMAB) produced from para‐aminothiophenol (PATP) by local surface plasmons was reported in 2010, and since that time a series of investigations have supported these findings using different experimental and theoretical methods. Recent work has also found that local plasmons can drive a surface‐catalyzed reaction of DMAB converted from 4‐nitrobenzenethiol (4NBT), assisted by local surface plasmons. There are at least three important discoveries in these investigations: 1) in the field of surface‐enhanced Raman scattering (SERS) the widely accepted misinterpretation (since 1994) that the chemical mechanism resulting in three additional Raman peaks of PATP in Ag or Au solutions has been corrected with a new mechanism; 2) it is confirmed that SERS is not always a noninvasive technique, and under certain conditions cannot always obtain the vibrational fingerprint information of the original surface species; 3) a novel method to synthesize new molecules, induced by local surface plasmons or plasmon waveguides on the nanoscale, has been found. This Review considers recent novel applications of plasmonics to chemical reactions, especially to plasmon‐driven surface‐catalyzed reactions.
Importance‐based data transmission optimization in multi‐source single‐sink wireless sensor networks
Authors: An Wei , Lin Jiajun , Shao Fang‐Ming , Luo Haiyan , Ci Song , Wu Dalei 
Published: July 2012

ABSTRACTEnergy‐efficient routing becomes one of the most critical technologies for sustaining the overall network lifetime of wireless sensor networks. In this paper, we propose a novel data transmission scheme between a number of specified source nodes and the single sink, which can efficiently restrict the usage frequency of each relay node, measured by the number of source nodes using it for data transmission. On the basis of the importance of source nodes that is closely related to deployed location, they form a descending sequence such that each node finds the minimum energy path earlier than the succeeding one. Then, the energy‐efficient multiple path algorithm with the computational complexity of O(n3) is developed for deriving the minimum energy paths, where n is the number of nodes in the network. Also, a polynomial algorithm is presented for deriving the range of the feasible values of N0 serving as the threshold of the usage frequency of relay nodes, in which each can guarantee the existence of the solution. Further, we theoretically investigate the existence of the solution and the tree‐structured solution using m‐ary tree. Extensive simulation results show that our proposed scheme can achieve significant performance enhancement. Copyright © 2012 John Wiley & Sons, Ltd.
Simulating the dynamics of wind turbine blades: part II, model validation and uncertainty quantification
Authors: Van Buren Kendra L. , Mollineaux Mark G. , Hemez François M. , Atamturktur Sezer 
Published: July 2012

ABSTRACTVerification and validation (V&V) offers the potential to play an indispensable role in the development of credible models for the simulation of wind turbines. This paper highlights the development of a three‐dimensional finite element model of the CX‐100 wind turbine blade. The scientific hypothesis that we wish to confirm by applying V&V activities is that it is possible to develop a fast‐running model capable of predicting the low‐order vibration dynamics with sufficient accuracy. A computationally efficient model is achieved by segmenting the geometry of the blade into six sections only. It is further assumed that each cross section can be homogenized with isotropic material properties. The main objectives of V&V activities deployed are to, first, assess the extent to which these assumptions are justified and, second, to quantify the resulting prediction uncertainty. Designs of computer experiments are analyzed to understand the effects of parameter uncertainty and identify the significant sensitivities. A calibration of model parameters to natural frequencies predicted by the simplified model is performed in two steps with the use of, first, a free–free configuration of the blade and, second, a fixed–free configuration. This two‐step approach is convenient to decouple the material properties from parameters of the model that describe the boundary condition. Here, calibration is not formulated as an optimization problem. Instead, it is viewed as a problem of inference uncertainty quantification where measurements are used to learn the uncertainty of model parameters. Gaussian process models, statistical tests and Markov chain Monte Carlo sampling are combined to explore the (true but unknown) joint probability distribution of parameters that, when sampled, produces bounds of prediction uncertainty that are consistent with the experimental variability. An independent validation assessment follows the calibration and is applied to mode shape vectors. Despite the identification of isolated issues with the simulation code and model developed, the overarching conclusion is that the modeling strategy is sound and leads to an accurate‐enough, fast‐running simulation of blade dynamics. This publication is Part II of a two‐part effort that highlights the V&V steps required to develop a robust model of a wind turbine blade, where Part I emphasizes code verification and the quantification of numerical uncertainty. Approved for unlimited public release on August 26, 2011, LA‐UR‐11‐4997. Copyright © 2012 John Wiley & Sons, Ltd.
Critical factors for high temperature processing of biomass from agriculture and energy crops to biofuels and bioenergy
Authors: Arvelakis Stelios , Koukios Emmanuel G. 
Published: July 2012

The demand for biomass for the production of energy in the forms of electric power, heat, and liquid fuels is growing fast over the last few years worldwide, mainly due to environmental concerns regarding the use of fossil fuels, such as coal, and oil. Agricultural residues, such as wheat straw, olive residue, and corn stover, as well as energy crops, e.g., Arundo donax, miscanthus, and switchgrass gain more and more interest as feedstocks to supply the vast amounts of biomass needed in order to produce the energy and liquid fuels required to fulfill the Kyoto protocol and reduce the environmental burdens of using fossil fuels in our planet. Biomass feedstocks can be converted to energy vectors in high‐efficiency thermochemical systems, such as pressurized fluidized bed boilers and gasifiers coupled with Fischer–Tropsch or other types of liquid fuel synthesis units, supercritical combustion units, and entrained flow combustors or gasifiers. This use is presently limited by the ash‐related problems associated with high‐temperature/high‐pressure environments. Inorganic bioresource constituents, such as alkali metals, chlorine, sulfur, and phosphorus, are the most troublesome elements responsible for several problems occurring. This paper presents a critical discussion regarding the main factors affecting the use of biomass of both agricultural residues and energy crops in high temperatures and high‐efficiency thermochemical conversion systems for the production of energy and liquid fuels. On the basis of an analysis of the particular problems, we identify solutions that could resolve these problems and assist significantly with a much higher production of energy and fuels from various biomass sources in an economical and sustainable way.This article is categorized under:

Bioenergy > Science and Materials
Energy Policy and Planning > Science and Materials
Breeding of lager yeast with Saccharomyces cerevisiae improves stress resistance and fermentation performance
Authors: Sanchez Rosa Garcia , Solodovnikova Natalia , Wendland Jürgen 
Published: July 2012

AbstractLager beer brewing relies on strains collectively known as Saccharomyces carlsbergensis, which are hybrids between S. cerevisiae and S. eubayanus‐like strains. Lager yeasts are particularly adapted to low‐temperature fermentations. Selection of new yeast strains for improved traits or fermentation performance is laborious, due to the allotetraploid nature of lager yeasts. Initially, we have generated new F1 hybrids by classical genetics, using spore clones of lager yeast and S. cerevisiae and complementation of auxotrophies of the single strains upon mating. These hybrids were improved on several parameters, including growth at elevated temperature and resistance against high osmolarity or high ethanol concentrations. Due to the uncertainty of chromosomal make‐up of lager yeast spore clones, we introduced molecular markers to analyse mating‐type composition by PCR. Based on these results, new hybrids between a lager and an ale yeast strain were isolated by micromanipulation. These hybrids were not subject to genetic modification. We generated and verified 13 hybrid strains. All of these hybrid strains showed improved stress resistance as seen in the ale parent, including improved survival at the end of fermentation. Importantly, some of the strains showed improved fermentation rates using 18°Plato at 18–25°C. Uniparental mitochondrial DNA inheritance was observed mostly from the S. cerevisiae parent. Copyright © 2012 John Wiley & Sons, Ltd.
Close relationships and attributions for peer victimization among late adolescents
Authors: Chen Xiaochen , Graham Sandra 
Published: July 2012

ABSTRACTThis study examined the effect of close relationships (best friendship and romantic relationship) on late adolescents' casual attributions for peer victimization. A total of 1106 twelfth grade students completed self‐report measures of perceived peer victimization, self‐blame attribution, psychological maladjustment (loneliness and social anxiety), and quality of close peer relationships. Results indicated that self‐blame partly mediated the link between peer victimization and psychological maladjustment. Relationship quality moderated the victimization–self‐blame relation. Participants were more likely to endorse self‐blame attributions for peer victimization when they had a negative relationship with a best friend or romantic partner. The moderated effect of negative best friendship quality was only significant for girls, whereas the moderated effect of negative romantic relationship quality was only significant for boys. Implications of these findings for future research on close relations during adolescence and for interventions to reduce the effects of peer victimization were discussed.