bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication of a model cellulose surface from straw with an aqueous sodium hydroxide/thiourea solution
Authors: Yan Lifeng , Wang Yiqun , Chen Juan 
Published: July 2008

AbstractModel cellulose surfaces were prepared with both microcrystalline cellulose and cellulose isolated from wheat straw with different molecular weights. A sodium hydroxide/thiourea aqueous solution, instead of any organic solvents, worked as the solvent for dissolving cellulose, and model cellulose films were prepared by a two‐step method: first, the cellulose solution was deposited onto the surface of the substrate with the spin‐coating method, and second, the as‐prepared film was washed with deionized water to remove the impurities and was formed with a flattened surface. Atomic force microscopy was used to measure the morphology, surface roughness, and thickness of the cellulose thin films. X‐ray photoelectron spectroscopy and energy‐dispersive X‐ray spectrometry were used to characterize the surface chemical information of the films. The results revealed that model cellulose surfaces could form from both kinds of cellulose. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, structural studies, and antimicrobial activity of polymeric copper(II) tetrathiocyanato diargentate(I) complexes with some acylhydrazones
Authors: Singh Vinod P. , Singh Archana , Singh Shweta 
Published: July 2008

AbstractCopper(II) complexes of the type Cu[Ag(SCN)2]2·L (where L is acetophenone benzoyl hydrazone, acetophenone isonicotinoyl hydrazone, acetophenone salicyloyl hydrazone, acetophenone anthraniloyl hydrazone, p‐hydroxyl acetophenone benzoylhydrazone, p‐hydroxyl acetophenone isonicotinoyl hydrazone, p‐hydroxyl acetophenone salicyloyl hydrazone, or p‐hydroxyl acetophenone anthraniloyl hydrazone) were synthesized and characterized. All the complexes were polymeric and insoluble in common organic solvent and were nonelectrolytes. The ligands were coordinated through >CO and >CN groups. All the SCN groups present in the complexes acted as bridges between two metal centers, resulting in a polymeric structure of the Lewis acid Cu[Ag(SCN)2]2 as well as its complexes. Electronic and electron spin resonance spectra suggested a square planar geometry for the Lewis acid and an elongated tetragonally distorted octahedral geometry for all the complexes. The powder X‐ray diffraction parameters for acetophenone salicyloyl hydrazone and p‐hydroxyl acetophenone anthraniloyl hydrazone complexes corresponded to orthorhombic and tetragonal crystal lattices, respectively. The complexes showed a fair degree of antifungal activity against Rizoctonia sp., Aspergillus sp., and Stemphylium sp. and moderate antibacterial activity against Clostridium sp. (Gram‐positive) and Pseudomonas sp. (Gram‐negative). The complexes were more active than the parent ligands. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of the composition ratio, eosin addition, and γ irradiation on the dielectric properties of poly(vinyl alcohol)/glycogen blends
Authors: Abd El‐Kader F. H. , Gaafar S. A. , Mahmoud K. H. , Bannan S. I. , Abd El‐Kader M. F. H. 
Published: July 2008

AbstractThe dielectric relaxation spectra of various poly(vinyl alcohol) (PVA)/glycogen blends and irradiated blend samples with 70 wt % PVA content that were undoped and doped with eosin were measured in extended temperature (30–160°C) and frequency (1 kHz to 1 MHz) ranges. Dielectric relaxation spectroscopy separates different molecular groups of a repeating unit of a polymer with respect to the rate of its orientation dynamics. In the high‐temperature range (>100°C), the σ relaxation, which is associated with the hopping motion of ions in the disordered structure of the biopolymeric material, can be measured. The electric dipole moment and the activation energy of the glass‐transition temperature relaxation process were calculated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Toughening of cycloaliphatic epoxy resin by multiwalled carbon nanotubes
Authors: Zhang Xiao‐Hua , Zhang Zheng‐Hua , Xu Wei‐Jian , Chen Fan‐Cai , Deng Jian‐Ru , Deng Xiao 
Published: July 2008

AbstractThe toughness of cycloaliphatic epoxy resin 3,4‐epoxycyclohexylmethyl‐3′,4′‐epoxycyclohexane carboxylate (ERL‐4221) has been improved by using multiwalled carbon nanotubes (MWCNTs) treated by mixed acids. The MWCNT/ERL‐4221 composites were characterized by Raman spectroscopy and their mechanical properties were investigated. A significant increase in the tensile strength of the composite from 31.9 to 55.9 MPa was obtained by adding only 0.05 wt % of MWCNTs. And a loading of 0.5 wt % MWCNTs resulted in an optimum tensile strength and cracking energy, 62.0 MPa and 490 N cm, respectively. Investigation on the morphology of fracture surface of the composites by field emission scanning electron microscopy demonstrated the crack pinning‐front bowing and bridging mechanisms of toughening. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymer‐acid solutions: Their use for the enhancement of oil reservoir stimulation
Authors: Amro Mohammed M. 
Published: July 2008

AbstractA reduction in permeability occurring around the wellbore resulting from drilling, completion and/or workover fluids increases the flow resistance to the petroleum reservoir fluids and is defined as formation damage. Acidizing process removes near‐wellbore damage and enhances hydrocarbon production from producing wells. This study investigates the effect of adding polymer as a retarding agent to acid solutions to slow and control the reaction in matrix acidizing treatment of carbonate rocks. Two different polymers, polyacrylamide (PAA) and polysaccharide (xanthan) and two different acids, acetic acid and formic acid, were used through this study. The results revealed that the presence of PAA did not change the viscosity of the acid solution significantly, while the viscosity of xanthan‐acid solutions was decreased with increasing the acid concentration. Additionally, the reaction of polymer‐acid solutions with the rock material was monitored under microscope. Original rock samples obtained from Saudi reservoirs containing mainly carbonate were used in the reaction. The PAA‐acid solution did not show any decrease in the reaction rate compared to that of acid solution. Thus, the PAA solution applied in this study is not recommended as a retarder. However, xanthan‐acid solutions showed a significant decrease in the reaction time. Therefore, xanthan was selected to perform further investigations in Rotating Disk Reactor at different pressures. Scanning electronic microscopy (SEM) was conducted on pretreated and posttreated rock samples. This provides the opportunity to perform a detailed description of the rock surface and facilitates the identification of the changes occurring due to polymer‐acid treatment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of iodine treatment on the carbonization behavior of Antheraea pernyi silk fibroin fiber
Authors: Rahman Khan Md. Majibur , Gotoh Yasuo , Morikawa Hideaki , Miura Mikihiko 
Published: July 2008

AbstractThe effect of iodine treatment on the carbonization behavior of tussah silk fibroin (SF) fiber from a wild cocoon, Antheraea pernyi (A. pernyi), was investigated, and the carbon yield, fiber morphology, structural characteristics, and mechanical properties were evaluated. The SF fiber was treated with iodine vapor at 100°C for 12 h and was heated to 800°C under a multistep heating program as carbonization process, which corresponds to the constant thermal degradation rate of SF determined by dynamic thermogravimetric analysis (TGA). The carbon yield was ca. 39 wt %, which is much higher than those for untreated A. pernyi. Scanning electron microscopic (SEM) observation showed that obtained carbon fibers from iodinated SF were structurally intact, and the strength was higher than that from untreated SF. Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction, and Raman spectroscopy revealed that the structures of the carbon fibers obtained from both untreated and iodinated SF were almost the same and amorphous. At the early stage of carbonization of SF, amide bonding of SF molecules was begin to collapse at temperatures higher than 350°C and was completely dissociated by carbonization at 800°C. Dynamic viscoelastic measurements showed that with heating above 270°C the iodine component introduced intermolecular crosslinking of SF and the melt flow of the SF was inhibited, which enhances higher carbon yield and better performance of silk based carbon fiber. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal properties and crystallization behavior of ultrafine fully‐vulcanized powdered rubber particle toughened polypropylene
Authors: Sun Dachun , Yuan Qiang , Jiang Wei 
Published: July 2008

AbstractThermal properties and crystallization behavior of ultrafine fully‐vulcanized powdered rubber (UFPR) toughened polypropylene (PP) were studied by Differential scanning calorimetry (DSC) and Wide angle X‐ray diffraction (WAXD) measurements. It was found that the fraction of β‐form in the PP crystal increased at first, then sharply deceased up to zero with increasing UFPR content. This trend did not rely on isothermal crystallization temperature. Moreover, DSC measurements implied that UFPR particles addition affected both isothermal and nonisothermal crystallization behaviors, including the crystallization temperature and the half‐time of crystallization. Furthermore, WAXD test results indicated that the addition of UFPR induced the orientation of the crystallites more or less. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Total Synthesis of an Anti‐Helicobacter pylori Agent, Actinopyrone A
Authors: Hosokawa Seijiro , Yokota Kazuya , Imamura Keisuke , Suzuki Yasuaki , Kawarasaki Masataka , Tatsuta Kuniaki 
Published: July 2008

AbstractActinopyrone A, an anti‐Helicobacter pylori agent, was synthesized in nine steps from a silyl dienol ether. A vinylogous anti‐aldol was stereoselectively synthesized by our developed remote stereoinduction methodology; coupling of this with a sulfone and a phosphonate species led to the construction of a vinylpyrone compound. This was submitted to reductive de‐conjugation to give actinopyrone A. The absolute stereochemistry of actinopyrone A was determined to have the configuration 14R,15R.
Dynamo coefficients from local simulations of the turbulent ISM
Authors: Gressel O. , Ziegler U. , Elstner D. , Rüdiger G. 
Published: July 2008

AbstractObservations in polarized emission reveal the existence of large‐scale coherent magnetic fields in a wide range of spiral galaxies. Radio‐polarization data show that these fields are strongly inclined towards the radial direction, with pitch angles up to 35° and thus cannot be explained by differential rotation alone. Global dynamo models describe the generation of the radial magnetic field from the underlying turbulence via the so called α ‐effect. However, these global models still rely on crude assumptions about the small‐scale turbulence. To overcome these restrictions we perform fully dynamical MHD simulations of interstellar turbulence driven by supernova explosions. From our simulations we extract profiles of the contributing diagonal elements of the dynamo α ‐tensor as functions of galactic height. We also measure the coefficients describing vertical pumping and find that the ratio $ \hat \gamma $ between these two effects has been overestimated in earlier analytical work, where dynamo action seemed impossible. In contradiction to these models based on isolated remnants we always find the pumping to be directed inward. In addition we observe that $ \hat \gamma $ depends on whether clustering in terms of superbubbles is taken into account. Finally, we apply a test field method to derive a quantitative measure of the turbulent magnetic diffusivity which we determine to be ∼2 kpckms–1. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prevention of NTDs with periconceptional multivitamin supplementation containing folic acid in China
Authors: Chen Gong , Song Xinming , Ji Ying , Zhang Lei , Pei Lijun , Chen Jiapeng , Liu Jufen , Li Chengfu , Zheng Xiaoying 
Published: July 2008

AbstractBACKGROUND: Maternal nutritional factors seem to contribute substantially to the complex etiologies of NTDs. Foremost among these factors is the periconceptional use of supplementation containing folic acid, which is associated with a reduction in the risk of women having NTD‐affected pregnancies. This study was designed to observe the effectiveness of multivitamin supplementation containing folic acid in preventing NTDs in a Chinese population and to detect factors that would impact the effectiveness. METHODS: Through family planning networks, a population‐based community intervention study was carried out in 18 counties of China. Participants were divided into an intervention (taking multivitamin) group and a control group, and were followed up according to periconceptional multivitamin supplementation (in general 6 mg) for 2 years. Women who had a pregnancy were followed up from 28 weeks gestation at least to pregnancy termination, and the outcome was recorded. The incidence rate of the two groups and the relative risks were calculated to evaluate the efficacy of the multivitamin supplement in preventing NTDs. RESULTS: During 2000 and 2002, all of the women having pregnancies with birth defects and women whose pregnancies were without any birth defects were interviewed. Nine NTDs were recorded from 25,444 pregnancies (NTD birth prevalence = 0.35/1,000 pregnancies) in the intervention group and 48 NTDs among 26,599 pregnancies (NTD birth prevalence = 1.80/1,000 pregnancies) in the control group. The protective rate was 80.4%. CONCLUSIONS: Periconceptional multivitamin supplementation containing folic acid can prevent the occurrence of NTDs with the beneficial effect dependent on the frequency and timing of the supplementation. Our study suggests that multivitamin supplement containing folic acid taken from a time point of 2 months before conception and continuing until completion of the second month after conception and taken more than five times per week can significantly reduce the risks of NTDs. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Parameter oscillation attenuation and mechanism exploration for continuous VHG ethanol fermentation
Authors: Bai F.W. , Ge X.M. , Anderson W.A. , Moo‐Young M. 
Published: July 2008

AbstractA bioreactor system composed of a stirred tank and three tubular bioreactors in series was established, and continuous ethanol fermentation was carried out using a general Saccharomyces cerevisiae strain and a very high gravity medium containing 280 g L−1 glucose, supplemented with 5 g L−1 yeast extract and 3 g L−1 peptone. Sustainable oscillations of glucose, ethanol, and biomass were observed when the tank was operated at the dilution rate of 0.027 h−1, which significantly affected ethanol fermentation performance of the system. After the tubular bioreactors were packed with 1/2″ Intalox ceramic saddles, the oscillations were attenuated and quasi‐steady states were achieved. Residence time distributions were studied for the packed bioreactors by the step input response technique using xylose as a tracer, which was added into the medium at a concentration of 20 g L−1, indicating that the backmixing alleviation assumed for the packed tubular bioreactors could not be established, and its contribution to the oscillation attenuation could not be verified. Furthermore, the role of the packing's yeast cell immobilization in the oscillation attenuation was investigated by packing the tubular bioreactors with packings with significant difference in yeast cell immobilization effects, and the experimental results revealed that only the Intalox ceramic saddles and wood chips with moderate yeast cell immobilization effects could attenuate the oscillations, and correspondingly, improved the ethanol fermentation performance of the system, while the porous polyurethane particles with good yeast cell immobilization effect could not. And the viability analysis for the immobilized yeast cells illustrated that the extremely lower yeast cell viability within the tubular bioreactors packed with the porous polyurethane particles could be the reason for their inefficiency, while the yeast cells loosely immobilized onto the surfaces of the Intalox ceramic saddles and wood chips could be renewed during the fermentation, guaranteeing their viability and making them more efficient in attenuating the oscillations. The packing Raschig rings without yeast cell immobilization effect did not affect the oscillatory behavior of the tubular bioreactors, further supporting the role of the yeast cell immobilization in the oscillation attenuation. Biotechnol. Bioeng. 2009;102: 113–121. © 2008 Wiley Periodicals, Inc.
Delayed death of identified reticulospinal neurons after spinal cord injury in lampreys
Authors: Shifman M.I. , Zhang G. , Selzer M.E. 
Published: July 2008

AbstractThere is controversy about whether axotomized neurons undergo death or only severe atrophy after spinal cord injury (SCI) in mammals. Lampreys recover from complete spinal transection, but only about half of the severed spinal‐projecting axons regenerate through the site of injury. The fates of the unregenerated neurons remain unknown, and until now death of axotomized spinal‐projecting neurons has not been described in the lamprey brain. We now report that in animals allowed to survive for 12 or more weeks after spinal cord transection, several identified reticulospinal (RS) neurons were missing in Nissl‐stained or neurofilament‐immunostained brain whole mounts. At earlier times, these neurons were swollen and pale in Nissl‐stained preparations. Retrograde fluorescent labeling from the site of transection combined with TUNEL histochemistry suggested that neuronal death, including that of the identified RS neurons, began in animals 4 weeks posttransection, reaching a peak at 12–16 weeks. This was not seen in untransected animals. The TUNEL positivity suggests that some cells were dying by apoptosis. Of special interest, among the identified neurons, this delayed cell death was restricted to neurons that at earlier posttransection times have a low probability of regeneration. These data show that SCI induces delayed cell death in lamprey spinal‐projecting neurons and suggest that the reason why some neurons are “bad regenerators” is that they are already undergoing apoptotic cell death. Thus protection from apoptosis may be necessary in order to enhance axonal regeneration after SCI. J. Comp. Neurol. 510:269–282, 2008. © 2008 Wiley‐Liss, Inc.
The accessory olfactory bulb in the adult rat: A cytological study of its cell types, neuropil, neuronal modules, and interactions with the main olfactory system
Authors: Larriva‐Sahd Jorge 
Published: July 2008

AbstractThe accessory olfactory bulb (AOB) in the adult rat is organized into external (ECL) and internal (ICL) cellular layers separated by the lateral olfactory tract (LOT). The most superficial layer, or vomeronasal nerve layer, is composed of two fiber contingents that distribute in rostral and caudal halves. The second layer, or glomerular layer, is also divided by a conspicuous invagination of the neuropil of the ECL at the junction of the rostral and caudal halves. The ECL contains eight cell types distributed in three areas: a subglomerular area containing juxtaglomerular and superficial short‐axon neurons, an intermediate area harboring large principal cells (LPC), or mitral and tufted cells, and a deep area containing dwarf, external granule, polygonal, and round projecting cells. The ICL contains two neuron types: internal granule (IGC) and main accessory cells (MACs). The dendrites and axons of LPCs in the two AOB halves are organized symmetrically with respect to an anatomical plane called linea alba. The LPC axon collaterals may recruit adjacent intrinsic, possibly γ‐aminobutyric acid (GABA)‐ergic, neurons that, in turn, interact with the dendrites of the adjacent LPCs. These modules may underlie the process of decoding pheromonal clues. The most rostral ICL contains another neuron group termed interstitial neurons of the bulbi (INBs) that includes both intrinsic and projecting neurons. MACs and INBs share inputs from fiber efferents arising in the main olfactory bulb (MOB) and AOB and send axons to IGCs. Because IGCs are a well‐known source of modulatory inputs to LPCs, both MACs and INBs represent a site of convergence of the MOB with the AOB. J. Comp. Neurol. 510:309–350, 2008. © 2008 Wiley‐Liss, Inc.
Cross‐domain authorization for federated virtual organizations using the myVocs collaboration environment
Authors: Gemmill Jill , Robinson John‐Paul , Scavo Tom , Bangalore Purushotham 
Published: July 2008

AbstractThis paper describes our experiences building and working with the reference implementation of myVocs (my Virtual Organization Collaboration System). myVocs provides a flexible environment for exploring new approaches to security, application development, and access control built from Internet services without a central identity repository. The myVocs framework enables virtual organization (VO) self‐management across unrelated security domains for multiple, unrelated VOs. By leveraging the emerging distributed identity management infrastructure. myVocs provides an accessible, secure collaborative environment using standards for federated identity management and open‐source software developed through the National Science Foundation Middleware Initiative. The Shibboleth software, an early implementation of the Organization for the Advancement of Structured Information Standards Security Assertion Markup Language standard for browser single sign‐on, provides the middleware needed to assert identity and attributes across domains so that access control decisions can be determined at each resource based on local policy. The eduPerson object class for lightweight directory access protocol (LDAP) provides standardized naming, format, and semantics for a global identifier. We have found that a Shibboleth deployment supporting VOs requires the addition of a new VO service component allowing VOs to manage their own membership and control access to their distributed resources. The myVocs system can be integrated with Grid authentication and authorization using GridShib. Copyright © 2008 John Wiley & Sons, Ltd.
Interventions and outcomes for children with dysphagia
Authors: Gisel Erika 
Published: July 2008

AbstractFeeding problems are common even in typically developing infants and children. However, they are more frequent and persistent in children with developmental disabilities. This article will provide an overview of current literature and a rationale underlying the interventions used for children with cerebral palsy (CP) who have eating impairments (dysphagia). The review is not intended to be exhaustive, but papers were selected that highlight some of the issues and challenges of the field. Normal oral‐motor development is briefly discussed to show how it may inform clinical practice in the understanding of feeding problems. Description of the risk factors and the nature and extent of eating impairments will show how interventions need to be specific to the severity of eating impairments. Examination of sensorimotor therapies, using oral stimulation exercises or an intra‐oral appliance, will highlight the range of their effectiveness, as well as their limitations. Similarly, an examination of tube feeding, used for nutritional rehabilitation of the most severely affected children, will address the benefits, controversies as well as moral issues encountered by caregivers and professionals. Multi‐center studies will be needed to obtain more homogeneous samples, large enough to address questions of early interventions and their subsequent effect on later development. © 2008 Wiley‐Liss, Inc. Dev Disabil Res Rev 2008;14:165–173.