bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine structural features of the acetylcholine innervation in the developing neostriatum of rat
Authors: Aznavour Nicolas , Mechawar Naguib , Watkins Kenneth C. , Descarries Laurent 
Published: April 2003

AbstractThe acetylcholine (ACh) innervation in the developing neostriatum of rat was examined by means of light and electron microscopic immunocytochemistry with a highly sensitive antibody against choline acetyltransferase (ChAT). ChAT‐immunoreactive cell bodies and their emerging processes, located at birth in the lateral part of neostriatum, progressively pervaded the whole region, to give rise to an extremely dense axonal network. As visualized and measured in single thin sections, at postnatal (P) ages P8, P16, and P32, the intrinsic and relational features of ChAT‐immunostained profiles of axon varicosities in the lateral and medial parts of neostriatum were similar to those previously described in the adult. At the three postnatal ages, the immunoreactive profiles were comparable in shape, size, and vesicular content, and displayed one or more mitochondria with increasing frequency (from 10% at P8 to 29% at P32). The proportion which showed a synaptic junction was low at the three ages (8–16%), indicating an average synaptic incidence of 22% for whole varicosities after stereological extrapolation. The observed junctions were relatively small, mostly symmetrical, and made with dendritic spines or branches. The frequency of synapses on spines versus branches increased with age, from 20% at P8 to almost 60% at P32. Thus, the relational features of the neostriatal ACh innervation were similar to adult as soon as it appeared, as previously observed to be the case in the developing cerebral cortex. The diffuse mode of transmission may therefore be characteristic of both ACh interneurons (neostriatum) and projection neurons (cerebral cortex) in the CNS, and could be determining their functional properties during development as well as at maturity. J. Comp. Neurol. 460:280–291, 2003. © 2003 Wiley‐Liss, Inc.
Iterative modal perturbation and reanalysis of eigenvalue problem
Authors: Liu X. L. , Oliveira C. S. 
Published: April 2003

AbstractThis paper presents an examination of the methods for the iterative modal perturbation and the application of these methods to the reanalysis of the eigenvalue problem. The iteration is based on the first‐order modal perturbation. In two examples, it is shown that the iterative analysis has the advantage of accuracy over the addition of higher‐order perturbations and it is an appropriate approach for the reanalysis of the eigenvalue problem in terms of accuracy and computational efficiency. Copyright © 2003 John Wiley & Sons, Ltd.
On higher‐order mixed FEM for low Mach number flows: application to a natural convection benchmark problem
Authors: Heuveline V. 
Published: April 2003

AbstractWe consider higher‐order mixed finite elements with continuous pressures for the computation of stationary compressible flows at low Mach number. The proposed approach is based on a fully coupled treatment of the governing equations and therefore, for steady‐state calculations, does not rely on time‐stepping techniques. The non‐linear problem is solved by means of a quasi‐Newton iteration. The strongly coupled system resulting from higher‐order discretization of the linearized equations requires adequate solvers. We propose a new scheme based on multigrid methods with varying FEM ansatz orders on the grid hierarchy as well as multiplicative smoothers based on blocking techniques. Computational results are described for a benchmark configuration including a flow with heat transfer in the low Mach number regime. Furthermore, the issue of anisotropic grids is addressed in that context. Copyright © 2003 John Wiley & Sons, Ltd.
Simple method to analyze SNP‐based association studies using DNA pools
Authors: Visscher Peter M. , Hellard Stéphanie Le 
Published: April 2003

AbstractAssociation studies using DNA pools are in principle powerful and efficient to detect association between a marker allele and disease status, e.g., in a case‐control design. A common observation with the use of DNA pools is that the two alleles at a polymorphic SNP locus are not amplified in equal amounts in heterozygous individuals. In addition, there are pool‐specific experimental errors so that there is variation in the estimates of allele frequencies from different pools that are from the same individuals. As a result of these additional sources of variation, the outcome of an experiment is an estimated count of alleles rather than the usual outcome in terms of observed counts. In this study, we show analytically and by computer simulation that unequal amplification should be taken into account when testing for differences in allele frequencies between pools, and suggest a simple modification of the standard χ2 test to control the type I error rate in the presence of experimental error variation. The impact of experimental errors on the power of association studies is shown. Genet Epidemiol 24:291–296, 2003. © 2003 Wiley‐Liss, Inc.
A note on genetic variance components in mixed models
Authors: Hazelton Martin L. , Gurrin Lyle C. 
Published: April 2003

AbstractBurton et al. ([1999] Genet. Epidemiol. 17:118–140) proposed a series of generalized linear mixed models for pedigree data that account for residual correlation between related individuals. These models may be fitted using Markov chain Monte Carlo methods, but the posterior mean for small variance components can exhibit marked positive bias. Burton et al. ([1999] Genet. Epidemiol. 17:118–140) suggested that this problem could be overcome by allowing the variance components to take negative values. We examine this idea in depth, and show that it can be interpreted as a computational device for locating the posterior mode without necessarily implying that the original random effects structure is incorrect. We illustrate the application of this technique to mixed models for familial data. Genet Epidemiol 24:297–301, 2003. © 2003 Wiley‐Liss, Inc.
Subcritical crack growth behavior of Al2O3‐glass dental composites
Authors: Zhu Qingshan , With Gijsbertus de , Dortmans Leonardus J. M. G. , Feenstra Frits 
Published: April 2003

AbstractThe purpose of this study is to investigate the subcritical crack growth (SCG) behavior of alumina‐glass dental composites. Alumina‐glass composites were fabricated by infiltrating molten glass to porous alumina preforms. Rectangular bars of the composite were subject to dynamic loading in air, with stressing rates ranging from 0.01 MPa/s to 2 MPa/s. The SCG parameter n was determined to be 22.1 for the composite, which is substantially lower than those of high‐purity dense alumina. Investigations showed that glass phases are responsible for the low n value as cracks propagate preferentially within glass phases or along the interface between glass phases and alumina phases, due to the fact that glasses are more vulnerable to chemical attacks by water molecules under stress corrosion conditions. The SCG behavior of the infiltration glass was also investigated and the SCG parameter n was determined to be 18.7. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 233–238, 2003
PMMA‐based bioactive cement: Effect of CaF2 on osteoconductivity and histological change with time
Authors: Shinzato Shuichi , Nakamura Takashi , Kawanabe Keiichi , Kokubo Tadashi 
Published: April 2003

AbstractA new bioactive bone cement (designated GBC), which is a polymethyl methacrylate‐ (PMMA‐) based composite consisting of bioactive glass beads as an inorganic filler and high‐molecular‐weight PMMA (hPMMA) as an organic matrix, has been developed. The bioactive glass beads consist of MgO‐CaO‐SiO2‐P2O5‐CaF2 glass. The purpose of the present study was to evaluate the effect of CaF2 on osteoconductivity and to evaluate the degree of cement degradation with time. Three different types of cement were prepared. GBC(F +), which has been previously described, consisted of CaF2‐containing bioactive glass beads and hPMMA. GBC(F −) consisted of CaF2‐free bioactive glass beads and hPMMA. The third cement was hPMMA itself (as a reference material). These three types of cement were packed into the intramedullary canals of rat tibiae to evaluate osteoconductivity, as determined by an affinity index calculated as the length of bone in direct contact with the cement surface expressed as a percentage of the total length of the cement surface. Rats were killed at 4, 8, 25, and 52 weeks after implantation, and the affinity index was calculated for each type of cement at each time point. Histologically, new bone had formed along the surface of both GBC(F +) and GBC(F −) within 4 weeks, whereas hPMMA had little contact with bone, and an intervening soft tissue layer between bone and cement was detected. No significant difference in affinity index was found between GBC(F +) and GBC(F −) at any of the time points studied, although GBC(F −) showed higher affinity indices than GBC(F +) at 8, 25, and 52 weeks. The affinity indices for GBC(F +) and GBC(F −) were significantly higher than those for hPMMA at all time points. With GBC(F +) and GBC(F −), significant increases in the affinity indices were found as the implantation period increased, and the affinity index values at 52 weeks reached more than 70%. In hPMMA, no significant increase in affinity index was observed up to 52 weeks, and the value at 52 weeks was less than 30%. Although no significant difference in affinity index was found between GBC(F +) and GBC(F −), GBC(F −) is conclusively better than GBC(F +) because diseases such as chronic fluorosis might be caused by CaF2‐containing glass beads. Regarding the cement degradation of both GBC(F +) and GBC(F −), the degree of the degradation at 25 weeks was the same as that at 52 weeks. Therefore, the cement degradation does not appear to proceed rapidly. Further studies are needed to better understand the degradation process. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 262–271, 2003
Development of a new poly(dimethylsiloxane) maxillofacial prosthetic material
Authors: Aziz Tariq , Waters Mark , Jagger Robert 
Published: April 2003

AbstractMaxillofacial prosthetic materials are used to rehabilitate patients suffering from acquired or congenital facial disfigurement. Silicone rubber materials [poly(dimethylsiloxane) rubbers] are the materials of choice. However, current formulations have inadequate mechanical properties, in particular, tear strength. The purpose of this study was to formulate a new poly(dimethylsiloxane) material with improved mechanical properties in comparison to commercially available materials. The formulations developed were based on condensation chemistry containing a hydroxy–end‐blocked poly(dimethylsiloxane), hydrophobic silica filler, silane cross‐linking agents, and a tin catalyst. The following parameters were varied in order to formulate improved materials: (a) bimodal polymeric mix (i.e., ratio of high‐ and low‐molecular‐weight polymers); (b) silica filler type and quantity. By varying these parameters a formulation was developed with a base polymer mix of 80%:20% high‐ to low‐molecular‐weight polymers into which 20% w/w filler was added. This formulation had a tear strength of 22.23 ± 1.6 m N/mm compared to the commercial materials having tear strengths in the range 4.53–17.63 N/mm. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 252–261, 2003
Wear of dental resin composites: Insights into underlying processes and assessment methods—A review
Authors: Turssi Cecilia Pedroso , de Moraes Purquerio Benedito , Serra Mônica Campos 
Published: April 2003

AbstractGiven the increased aesthetic demands of patients, along with improvements in the formulation of resin composites, the ability of these materials to bond to tooth structures, and concerns about dental amalgam fillings, the applicability of resin composites in dentistry has become increasingly widespread. As resistance to wear represents an important factor in determining the clinical success of resin composite restoratives, the aim of this article was to define what constitutes wear; the major underlying phenomena involved in this process—adhesion, abrasion, fatigue, and corrosion—being described. Discussions were also focused on factors that contribute both to the magnitude and minimization of resin composite wear. Finally, insights were included on both in vivo and laboratory studies used to determine wear resistance. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 280–285, 2003
Synthesis of [18F]FETO, a novel potential 11‐β hydroxylase inhibitor
Authors: Wadsak Wolfgang , Mitterhauser Markus 
Published: April 2003

AbstractRecent publications reported high uptake of the carbon‐11 labelled 11β‐hydroxylase inhibitors (R)–[O–methyl‐11C]metomidate ([11C]MTO) and (R)–[O–ethyl‐11C]etomidate ([11C]ETO) in adrenocortical incidentalomas with excellent selectivity for positron emission tomography (PET). In our studies [18F]FETO, (the [18F]fluoroethyl ester of etomidate, (R)‐1‐(1‐phenylethyl)‐1H‐imidazole‐5‐carboxylic acid, 2′‐[18F]fluoroethyl ester), an analogue of [11C]MTO and [11C]ETO was chosen due to the suspected similarity of the pharmacokinetic and pharmacodynamic properties, and was prepared in the following two step procedure: First, [18F]fluoride was reacted with 2‐bromoethyl triflate using the kryptofix/acetonitrile method to yield 2–bromo‐[18F]fluoroethane ([18F]BFE). In the second step, [18F]BFE was reacted with the tetrabutylammonium salt of (R)‐1‐(1‐phenylethyl)‐1H‐imidazole‐5‐carboxylic acid to yield [18F]FETO, a novel inhibitor of the 11β‐hydroxylase. The proposed synthesis of [18F]FETO allows the production of sufficient amounts of this new PET‐tracer to serve 1–2 patients with an overall synthesis time of less than 80 min. Copyright © 2003 John Wiley & Sons, Ltd.
Inverted‐L slot antenna for WLAN operation
Authors: Su Chih‐Ming , Chen Hong‐Twu , Wong Kin‐Lu 
Published: April 2003

AbstractAn inverted‐L slot antenna for wireless local area network (WLAN) operation in the 2.4‐GHz band (2400–2484 MHz) is presented. The inverted‐L slot antenna is obtained by transforming a linear slot into an inverted‐L shaped, which makes it very suitable to be placed at the corners of the display panel of a notebook computer. A prototype has been constructed and tested, and good antenna gain and dual‐polarization radiation characteristics for WLAN operations are observed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 315–316, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10905
A study of optical pulse characters extracted from supercontinuum by filters
Authors: Wang Jianping , Wu Yue , Lou Caiyun , Gao Yizhi 
Published: April 2003

AbstractSupercontinuum (SC) pumped by a 10‐GHz active mode‐locked Er3+‐doped fiber‐ring laser (AML‐EDFL) has been gained and the characteristics of the optical pulses extracted from SC have been studied. The central wavelength, bandwidth, and shape of the filters will have important effects on the optical pulses' output. Some conclusions about the filters are drawn from using SC as the optical source for a wavelength‐division multiplexing over optical‐time‐division multiplexing (WDM/OTDM) transmission system. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 387–390, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10926
Gliclazide‐induced hepatitis
Authors: Subramanian G , Walmsley D , Blewitt RW 
Published: April 2003

AbstractA 64‐year‐old man presented with tiredness, and a diagnosis of type 2 diabetes was made based on two raised random blood glucose values. He was commenced on gliclazide. Three months later, blood investigations revealed elevated liver enzymes (hepatitic pattern). Further investigations revealed no obvious cause for his abnormal liver function tests. Gliclazide was discontinued and a subsequent liver biopsy revealed features consistent with an acute hepatitis. His liver function tests returned to normal three months after discontinuation of gliclazide. Copyright © 2003 John Wiley & Sons, Ltd.
Randomized controlled trial of three different doses of aerosol beclomethasone versus systemic dexamethasone to promote extubation in ventilated premature infants
Authors: Rozycki Henry J. , Byron Peter R. , Elliott Greg R. , Carroll Timothy , Gutcher Gary R. 
Published: April 2003

AbstractOur objective was to determine the safety and efficacy of aerosol beclomethasone vs. systemic dexamethasone for extubation in premature infants at high risk for chronic lung disease (CLD). Intubated preterm infants who were identified as being at high risk for moderate‐severe CLD on day 14 of life were randomized to one of four groups. The control group received systemic dexamethasone and aerosol placebo, while the other three groups received either high (2.40–3.69 μg/kg/day delivered to lungs), medium (1.0–1.85 μg/kg/day), or low (0.48–0.74 μg/kg/day) dose aerosol beclomethasone and systemic placebo. Those receiving aerosol steroids who remained ventilator‐dependent after 7 days were switched to standard 42‐day tapering doses of systemic dexamethasone. The primary outcome was extubation within 1 week of starting steroids, using predefined criteria. Secondary variables included changes in lung function, rates of side effects, and tracheal aspirate white blood cell counts. Sixty‐one infants with birth weights of 761 ± 18 g (mean ± SEM) and gestational ages of 25.7 ± 0.2 weeks were randomized to one of the four groups. Seven of 15 infants in the control systemic dexamethasone group were successfully extubated compared with 3/16 in the high‐dose beclomethasone group, 1/15 in the medium‐dose group, and 2/15 in the low‐dose group (P < 0.01). Only dexamethasone subjects demonstrated improvements in lung function over the study period. These infants also had significant increases in blood pressure and blood glucose levels, as well as a decline in their tracheal aspirate white blood cell count. In conclusion, aerosol beclomethasone at the very low doses used in this study did not facilitate extubation in intubated premature infants at high risk for moderate‐severe CLD. Pediatr Pulmonol. 2003; 35:375–383. © 2003 Wiley‐Liss, Inc.
Different effect of age on dopamine transporters in the dorsal and ventral striatum of controls and alcoholics
Authors: Tupala Erkki , Hall Håkan , Bergström Kim , Mantere Tuija , Räsänen Pirkko , Särkioja Terttu , Hiltunen Jukka , Tiihonen Jari 
Published: April 2003

AbstractIt is generally agreed that there is a deterioration in brain dopamine (DA) system with aging. The role of the mesolimbic DA in brain ethanol reinforcement is well established, with nucleus accumbens (NAC) serving as a major terminal area of this system, whereas dorsal striatum is more associated with motor control. The aim of this study was to compare putative age‐related alterations of dopamine transporters (DAT) in dorsal and ventral striatum of healthy controls and alcoholics. We studied the effect of age on DAT in caudate (NC), putamen (Pu), and nucleus accumbens (NAC) of eight type 1 and 2 alcoholics and 10 healthy controls by using [125I]PE2I as a radioligand for postmortem human whole hemisphere autoradiography. In the type 1 alcoholic group age and DAT density did not correlate significantly with any of the structures studied. The mean densities of DAT declined significantly with age in controls and type 2 alcoholics in dorsal striatum (NC, Pu) (range of correlation coefficient from −0.49 to −0.94), but not statistically significantly in NAC. In type 1 alcoholics the lack of correlation between DAT density and age may indicate a preexisting dopaminergic deficit in this patient group, whereas age‐related decline among type 2 alcoholics resembled that of healthy controls. Furthermore, dorsal striatal DAT may be more vulnerable to age‐related decline than DAT in NAC. This is supported by the notion that DAT in NAC and dorsal striatum have different molecular weights. Synapse 48:205–211, 2003. © 2003 Wiley‐Liss, Inc.
Age‐related loss of synapses in the frontal cortex of SAMP10 mouse: A model of cerebral degeneration
Authors: Shimada Atsuyoshi , Keino Hiromi , Satoh Mamoru , Kishikawa Masao , Hosokawa Masanori 
Published: April 2003

AbstractSAMP10 mouse is a model of brain aging in which senescence is characterized by cerebral atrophy most prominent in the frontal cortex, deterioration in performance of learning and memory tasks, and alterations of the central dopaminergic system. The present study investigates age‐related changes in the expression of synapse‐related proteins to determine whether the number of synapses is decreased in SAMP10 mice. We quantified expression levels of synaptophysin, a presynaptic protein, and of PSD‐95, a postsynaptic protein in various brain regions by immunoblotting. Both synapse‐related proteins (52% of synaptophysin and 55% of PSD‐95) were lost from the anterior cerebral cortex in SAMP10 mice at age 10–12 months compared with those in mice at age 3 months. Synaptophysin was lost by 30% from the posterior cerebral cortex of SAMP10 mice at age 15–16 months. The level of synaptophysin, but not of PSD‐95 decreased by about 25% in the brain stem of SAMP10 mice aged 7 and 10–12 months. A loss of synapse‐related proteins was not significant in other brain regions. Age‐related loss of synaptophysin or PSD‐95 was not evident in normal aging control SAMR1 mice that do not develop brain atrophy. In summary, synapses were lost with aging in SAMP10 mice and the synaptic loss was most prominent in the anterior cerebral neocortex. Since a loss of neocortical synapses is the primary correlate with the intellectual decline in human neurodegenerative diseases, SAMP10 mouse is a useful model with which to study the mechanisms underlying synaptic loss in human neurodegenerative dementias. Synapse 48:198–204, 2003. © 2003 Wiley‐Liss, Inc.
Contribution to the welfare of captive wolves (Canis lupus lupus): A behavioral comparison of six wolf packs
Authors: Frézard Anne , Pape Gilles Le 
Published: April 2003

AbstractAn interesting way to understand and eventually improve the well‐being of captive animals is to compare different living and social conditions, in order to analyze the behavioral differences between animals living in very restrictive conditions and animals enjoying more permissive ones. In the present study we performed 10 observations of six wolf enclosures with quite different living and social conditions. The rest/activity balance, behavioral diversity, and use of available space were used as welfare criteria. Results show that the proportion of time resting was higher in large, comfortable enclosures. In each park, animals used only a part of the available space, the proportion being lower in large enclosures. The behavioral diversity was little affected by the size of the enclosure, but highly related to the composition of the pack. The results underline the importance of spatial choice and social group management. Zoo Biol 22:33–44, 2003 © 2003 Wiley‐Liss, Inc.