bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ATH content on electrical and aging properties of EVA and silicone rubber blends for high voltage insulator compound
Authors: Pradeep M. A. , Vasudev N. , Reddy P. V. , Khastgir D. 
Published: March 2007

AbstractThe effect of trihydrated alumina (Al2O3, 3H2O) (ATH) filler in ethylene‐vinyl acetate copolymer (EVA) and silicone rubber blends was investigated by performing a series of laboratory experiments to simulate different natural aging conditions. Samples with varying ATH content in a 50‐50 blend of EVA and polydimethylsiloxane (PDMS) (silicone rubber, MQ) were tested to investigate the tracking resistance, resistance to UV radiation, corona, heat, and water immersion. Changes in surface resistivity, volume resistivity, and hydrophobic characteristics were evaluated for different compounds having ATH content. These exercises were mainly carried out to optimize the filler level. In immersed condition the water absorption increases with ATH content. The recovery of hydrophobicity, after aging by heat, is appreciable at higher ATH levels, than at lower ATH levels. The tracking and erosion resistance decrease as ATH content increases. When compounds containing different ATH content were subjected to corona treatment, the samples with higher ATH levels exhibited better results. All samples changed their color to a darker shade and there was an increase in the hydrophobicity, when subjected to UV radiation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3505–3516, 2007
Phenolics from Extracts of Brahea armata with Inhibitory Effect Against 5α‐Reductase Type‐II.
Authors: Hussein S. A. , Hashim A. N. , Barakat H. H. , Jose J. , Lindequist U. , Nawwar M. A. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design and Function of Low Molecular‐Mass Organic Gelators (LMOGs) Bearing Steroid and Sugar Groups
Authors: Fujita Norifumi , Shinkai Seiji 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Neonatal alcohol exposure impairs acquisition of eyeblink conditioned responses during discrimination learning and reversal in weanling rats
Authors: Brown Kevin L. , Calizo Lyngine H. , Goodlett Charles R. , Stanton Mark E. 
Published: March 2007

AbstractDiscrimination and reversal of the classically conditioned eyeblink response depends on cerebellar–brainstem interactions with the hippocampus. Neonatal “binge” exposure to alcohol at doses of 5 g/kg/day or more has been shown to impair single‐cue eyeblink conditioning in both weanling and adult rats. The present study exposed neonatal rats to acute alcohol intubations across different developmental periods (postnatal day [PND] 4‐9 or PND7‐9) and tested them from PND26‐31 on discriminative classical eyeblink conditioning and reversal. A high dose of alcohol (5 g/kg/day) dramatically impaired conditioning relative to controls when exposure occurred over PND4‐9, but produced mild or no impairments when delivered over PND7‐9. These findings support previous claims that developmental exposure period plays a critical role in determining the deleterious effects of alcohol on the developing brain. A lower dose of alcohol (4 g/kg/day) delivered from PND4‐9—lower than has previously been shown to affect single‐cue eyeblink conditioning—also produced deficits on the discrimination task, suggesting that discrimination learning and acquisition of responding to CS+ during reversal may be especially sensitive behavioral indicators of alcohol‐induced brain damage in this rat model. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 243–257, 2007.
Safety of structural systems with reserve elements for earthquake protection
Authors: Eisenberg I. M. 
Published: March 2007

AbstractSome results of approximate analyses of the safety of earthquake protection systems with reserve elements are presented. Systems with one and several reserve elements are considered. The overshoot random vibration approximation is used for analysis. A numerical example is given. It is shown that the failure probability of structures with reserve elements is considerably lower and the safety is much higher when compared with similar characteristics of structures without reserve elements.
Dynamic response of a submerged hemispherical shell to earthquake motions
Authors: Akkał Nuri 
Published: March 2007

AbstractThe dynamic response to ground motion of hemispherical shells in a fluid, medium is studied numerically. In the analysis, linear thin shell theory is used and the fluid is assumed to be compressible and inviscid. The effect of the duration of the ground motion on the dynamic response is studied using two forcing functions, one with a very short duration and the other in the form of a Heaviside function. As special cases, dynamic responses of the shell in vacuo and of a rigid hemisphere in the fluid medium are investigated. The results are valid also for a ring‐stiffened complete spherical shell accelerating in an acoustic medium.
Approximate frequency analysis of shear wall frame structures
Authors: Cheung Y. K. , Kasemset C. 
Published: March 2007

AbstractThe finite strip method is used to determine the natural frequencies of shear wall frame buildings. The structure can be modelled in two different ways. In the first approach both the shear walls and the frames are idealized simply as an assemblage of finite strips of varying thicknesses with given or computed properties, while in the second approach the shear walls are still idealized as a series of finite strips, but the frames are regarded as a number of long columns which are interconnected with each other or with finite strips through the horizontal beams. Numerical results obtained from both models indicate good agreement with finite element solutions. The proposed models can be applied to a wide range of shear wall frame assemblies and are therefore more versatile than most existing models.
An improved fluid superelement for the coupled solid‐fluid‐surface wave dynamic interaction problem
Authors: Dubois J. J. , De Rouvray A. L. 
Published: March 2007

AbstractThe dynamic solid‐fluid‐surface wave interaction problem can be solved with known Finite Element solutions. However, these solutions are complicated by the unsymmetric nature of the matrix equation to be solved.This paper shows how the numerical problem can be simplified by symmetrization, without loss of physical generality, using specialized Lagrange co‐ordinates for the fluid free surface wave, and by introducing a Lagrange multiplier representing a generalized fluid pressure.With these improvements, solid‐fluid‐surface wave analysis capabilities can easily be added to most Finite Element structural analysis programs. Numerical examples of the performance of the improved formulation are given for earthquake analysis.
Triton X‐100 Pretreatment of LR‐white Thin Sections Improves Immunofluorescence Specificity and Intensity
Authors: Ghrebi Salem S. , Owen Gethin Rh. , Brunette Donald M. 
Published: March 2007

AbstractThe staining of intracellular antigenic sites in postembedded samples is a challenging problem. Deterioration of antigenicity and limited antibody accessibility to the antigen are commonly encountered on account of processing steps. In this study preservation of the antigen was achieved by fixing the tissues with mild fixatives, performing partial dehydration, and embedding in a low crosslinked hydrophilic acrylic resin, LR‐White. Permeabilization of cell membranes with Triton X‐100 is well documented but can affect some antigen conformations. We tested the effect of Triton X‐100 on the ED1 antigen present in the lysosomal membrane of the macrophage in cell culture. The ED1 antigen in the lysosome was resistant to extraction by Triton X‐100. Interestingly pretreating the LR‐White sections of macrophage pellets with Triton X‐100 improved the staining intensity of ED1. The most intense and clear specific fluorescent staining was observed when sections were pretreated with 0.2% Triton X‐100 for 2 min. Longer exposure of sections to 0.2% Triton or 2 min exposure to 2% Triton lead to reduced ED1 labeling. SEM observations indicated that the detergent extracted a component from the cells and not the resin and was determined to be lipid. This novel technique could be applied in many research areas where postembedding fluorescent immunolabeling with higher labeling intensity is desired. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Downscaling of current and future rainfall climatologies for southern Morocco. Part I: Downscaling method and current climatology
Authors: Huebener H. , Kerschgens M. 
Published: March 2007

AbstractThe use of a statistical‐dynamical downscaling approach to obtain a high‐resolution rainfall climatology for a subtropical region in southern Morocco is analysed. The statistical part of the downscaling uses Circulation Weather Types (CWTs) as a measure for near‐surface wind fields calculated from sea‐level pressure (SLP) data. The daily CWTs are correlated with daily rainfall data at three different climate stations in the region for the period 1978–1997 and systematic differences are discussed. Results are viewed for one extreme dry year (1984) and one extreme wet year (1989) to show the limits of purely statistical downscaling.Dynamical downscaling is realized for representative days to enable statistical‐dynamical downscaling. Comparison of statistically‐dynamically downscaled rainfall with measured rainfall for the year 2002 and climatological results show that the method is capable of capturing the relevant mechanisms triggering rainfall in the area. For extreme dry (wet) years, rainfall is overestimated (underestimated) by the method and errors might occur even for normal years. However, application to a climatology calculated for the period 1958–1997 via analysing daily SLP fields from NCEP Reanalyses gives satisfactory results. For sufficiently long periods, the method is well capable of producing a reliable high‐resolution rainfall climatology. We will therefore apply the method to climate change simulations in part II of this paper. Copyright © 2007 Royal Meteorological Society
Radical Telomerisation of Vinyl Phosphonic Acid with a Series of Chain Transfer Agents
Authors: David Ghislain , Boutevin Bernard , Seabrook Shane , Destarac Mathias , Woodward Gary , Otter Graham 
Published: March 2007

AbstractThe use of CTAs for the radical polymerisation of VPA has been successfully applied for the first time. Several CTAs were investigated, including thiol, disulfide and halogenated compounds. The use of mercaptoacetic acid led to the synthesis of the mercaptan VPA monoadduct, which was attributed to a high transfer constant (CT = ktr/kp) of approximately 7. Transfer reactions with VPA appeared to be unsuccessful when using benzyldisulfide, 1,1,1‐trichloroethane and trichloroacetic acid. Application of bromotrichloromethane as a transfer agent led to the oligomerisation of VPA, with final conversion being approximately 80%. The transfer events were characterised by 13C NMR, MALDI‐TOF and elemental analysis. Molecular weights of the successful VPA polymerisations showed values ranging from 600 to 5 000 g · mol−1, which were in close agreement with the theoretically calculated values.magnified image
Fabrication and Properties of Cellulose Hydrated Membrane with Unique Structure
Authors: Liang Songmiao , Zhang Lina , Li Yanfang , Xu Jian 
Published: March 2007

AbstractBy employing a pre‐gelation processing of cellulose solution, this work has presented a new method to prepare cellulose hydrated membranes in NaOH/thiourea aqueous solvent system. The morphology and structure of the hydrated membranes obtained at different pre‐gelation temperatures were studied by scanning electron microscopy (SEM), wide‐angle X‐ray diffractometry (WAXD), and attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR). The mechanical properties of the membranes were studied by tensile testing. Using a double‐cell method, permeation of three model drugs (ceftazidine, cefazolin sodium, thiourea) through the hydrate membranes was determined in phosphate buffer solution at body‐like temperature (37 °C). The results indicate that the membranes were packed densely by many hydrated nanospheres and exhibited good mechanical properties. At a relatively low pre‐gelation temperature, the strain and the stress at break of the membranes are even up to 192% and 1.97 MPa, which are much larger than that of the hydrated membranes prepared by the general solution casting method. For the first time, the formation process of the hydrated membrane from gel state in water was investigated by ATR‐FTIR spectrum, indicating a non‐solvent‐induced phase‐separation mechanism.magnified image
Low‐Melting Nematic Quasi‐Rigid Rod‐Like Polyesters
Authors: Osman Maged A. 
Published: March 2007

AbstractThermotropic quasi‐rigid rod‐like polyesters with broad nematic phases in temperature ranges that allow melt processing in the mesophase have been synthesized. The desired mesomorphic temperature range can be realized by adjusting the chain flexibility and packing density as well as the axial ratio of the mesogenic segments. The chain flexibility was slightly increased without giving the molecule much conformational freedom by introducing ethylene or dioxyethylene linkages between the phenyl groups of the aromatic polyester (preferably in the acid part of the molecule). The sensitive balance between the axial ratio of the mesogenic segments and the chain flexibility was preserved to retain the mesogeneity of the molecule. Replacing some of the planar aromatic phenyl groups by staggered trans‐cyclohexyl moieties effectively depresses Tm without affecting Ti. The effect of symmetrical and asymmetrical lateral substitution with alkyl groups of different van der Waals volume on Tm and Ti was studied. Asymmetric lateral substitution is quite effective in depressing Tm with little effect on Ti. Combinations of these structural modifications are useful tools to adjust the mesomorphic properties of liquid crystalline polyesters.magnified image
Threshold Temperature Sensors with Tunable Properties
Authors: Crenshaw Brent R. , Kunzelman Jill , Sing Charles E. , Ander Christine , Weder Christoph 
Published: March 2007

AbstractThermochromic polymer/dye blends based on small amounts (0.6–2.3 wt.‐%) of chromogenic sensor dyes and glassy amorphous polymers were prepared. Subjecting melt‐processed, quenched blends to temperatures above Tg leads to permanent and pronounced changes of their absorption and fluorescence spectra as a result of phase separation and assembly of dye aggregates. The influence of dye structure and polymer Tg on the aggregation kinetics of these blends was investigated. It is shown that increasing the length of the dye's rigid core leads to slower aggregation rates due to limited mobility in the polymer. The threshold of the color change can be tailored by adjusting the polymer Tg, as was shown by the systematic investigation of blends based on poly(alkyl methacrylate) copolymers of varying composition.magnified image
The moderating influence of mother‐adolescent discussion on early and middle African‐American adolescent sexual behavior
Authors: DiIorio Colleen , McCarty Frances , Denzmore Pamela , Landis Andrea 
Published: March 2007

AbstractWe examined how African‐American mothers' discussions with their adolescents about sex moderated the relationship between adolescents' sex‐based discussions with their friends and adolescents' involvement in sexual behaviors. The 425 African‐American adolescents were 12 through 15 years of age and had participated in an HIV prevention research project with their mothers. Linear and logistic regression analyses showed that, for girls, age, discussions with friends, and the interaction between mother and friend's	sex‐based discussions were statistically significant predictors of sexual behaviors. These findings suggest that the level of discussion with mothers had a moderating effect on the relationship between friends' discussions about sex and a girl's involvement in sexual behaviors. Although these results were not apparent for boys, there was a strong relationship between discussions with friends about sex and sexual behaviors among boys. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30: 193–202, 2007
Fast and reliable analysis of molecular motion using proximity relations and dimensionality reduction
Authors: Plaku Erion , Stamati Hernán , Clementi Cecilia , Kavraki Lydia E. 
Published: March 2007

AbstractThe analysis of molecular motion starting from extensive sampling of molecular configurations remains an important and challenging task in computational biology. Existing methods require a significant amount of time to extract the most relevant motion information from such data sets. In this work, we provide a practical tool for molecular motion analysis. The proposed method builds upon the recent ScIMAP (Scalable Isomap) method, which, by using proximity relations and dimensionality reduction, has been shown to reliably extract from simulation data a few parameters that capture the main, linear and/or nonlinear, modes of motion of a molecular system. The results we present in the context of protein folding reveal that the proposed method characterizes the folding process essentially as well as ScIMAP. At the same time, by projecting the simulation data and computing proximity relations in a low‐dimensional Euclidean space, it renders such analysis computationally practical. In many instances, the proposed method reduces the computational cost from several CPU months to just a few CPU hours, making it possible to analyze extensive simulation data in a matter of a few hours using only a single processor. These results establish the proposed method as a reliable and practical tool for analyzing motions of considerably large molecular systems and proteins with complex folding mechanisms. Proteins 2007. © 2007 Wiley‐Liss, Inc.
EADock: Docking of small molecules into protein active sites with a multiobjective evolutionary optimization
Authors: Grosdidier Aurélien , Zoete Vincent , Michielin Olivier 
Published: March 2007

AbstractIn recent years, protein–ligand docking has become a powerful tool for drug development. Although several approaches suitable for high throughput screening are available, there is a need for methods able to identify binding modes with high accuracy. This accuracy is essential to reliably compute the binding free energy of the ligand. Such methods are needed when the binding mode of lead compounds is not determined experimentally but is needed for structure‐based lead optimization. We present here a new docking software, called EADock, that aims at this goal. It uses an hybrid evolutionary algorithm with two fitness functions, in combination with a sophisticated management of the diversity. EADock is interfaced with the CHARMM package for energy calculations and coordinate handling. A validation was carried out on 37 crystallized protein–ligand complexes featuring 11 different proteins. The search space was defined as a sphere of 15 Å around the center of mass of the ligand position in the crystal structure, and on the contrary to other benchmarks, our algorithm was fed with optimized ligand positions up to 10 Å root mean square deviation (RMSD) from the crystal structure, excluding the latter. This validation illustrates the efficiency of our sampling strategy, as correct binding modes, defined by a RMSD to the crystal structure lower than 2 Å, were identified and ranked first for 68% of the complexes. The success rate increases to 78% when considering the five best ranked clusters, and 92% when all clusters present in the last generation are taken into account. Most failures could be explained by the presence of crystal contacts in the experimental structure. Finally, the ability of EADock to accurately predict binding modes on a real application was illustrated by the successful docking of the RGD cyclic pentapeptide on the αVβ3 integrin, starting far away from the binding pocket. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Strategic groups, competitive groups and performance within the U.K. pharmaceutical industry: Improving our understanding of the competitive process
Authors: Leask Graham , Parker David 
Published: March 2007

AbstractStrategic group research originated in the 1970s and a number of notable studies centered on the U.S. pharmaceutical industry. Results were, however, conflicting. This paper explores the nature of strategic groups in the U.K. pharmaceutical industry. The study confirms the presence of between six and eight strategic groups across the period studied, 1998–2002. The study also demonstrates a statistically significant relationship between these strategic groups and performance using three performance measures. The paper then compares strategic groups with competitive groups and concludes that the distinction is important and may explain the contradictory findings in earlier strategic group research. Copyright © 2007 John Wiley & Sons, Ltd.
Reevaluation of grading standards and discounts for fungus‐damaged soybean seeds
Authors: Sinclair James B. 
Published: March 2007

AbstractThe proportion of off‐colored seed is a primary quality‐rating factor that influences the market grade of soybean,Glycine max L. Merrill. Off‐colors, attributed to biological agents such as fungi and viruses, are visual characteristics that arbitrarily result in lower grade ratings when soybeans show more than ten percent discoloration. These damaged seeds may be further classified under current United States Department of Agriculture, Federal Grain Inspection Service standards as: moldy, weathered, bicolored, mottled, or other colors. Presently, all types of fungal damage and virus symptoms are evaluated equally in the application of discount schedules at grain‐elevators. However, recent information shows that superficial discoloration caused by some biological agents does not lower grain quality. Indeed, methods are available to distinguish those symptoms that actually reduce seed quality from those that are more cosmetic in nature. This communication provides guidance on fungi that are involved most often in seed damage or discoloration. The following organisms are listed in descending order of importance:Phomopsis longicolla, Alternaria, Nematospora coryli, Fusarium graminearum, Colletotrichum, andCercospora kikuchii. Discoloration caused byPeronospora manchurica (downy mildew) and the soybean mosaic virus have limited effect on seed quality. Discoloration caused by each of these agents may be identified by recognizable characteristics. Therefore, knowledge of the relative impact of these organisms on seed quality should be practiced in the application of soybean grading standards and discount schedules.