bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methamphetamine exposure during the preweanling period causes prolonged changes in dorsal striatal protein kinase A activity, dopamine D2‐like binding sites, and dopamine content
Authors: Crawford Cynthia A. , Williams Michael T. , Newman Eva R. , McDougall Sanders A. , Vorhees Charles V. 
Published: March 2003

AbstractExposure to methamphetamine (METH) during the preweanling period produces few, if any, neurotoxic effects (using criteria established in adult rats), yet it has substantial long‐term effects on a variety of behavioral measures (e.g., locomotor activity, acoustic startle response, and spatial learning). The purpose of the present study was to examine the long‐term changes in dopaminergic functioning brought about by early METH exposure. Rats were injected with METH (10 mg/kg) or saline four times daily on postnatal days (PD) 11–20 and housed undisturbed until PD 90, at which time they were killed and their dorsal striata (i.e., caudate–putamen) were removed and frozen for assay. The ability of early METH exposure to alter protein kinase A (PKA) activity and dopamine (DA) D2‐like binding sites, as well as DA and DOPAC content, were assessed. Results showed that METH exposure on PD 11–20 caused long‐term reductions in all of the dopaminergic markers assayed. METH‐induced reductions in DA content and D2‐like receptors were observed. Some sex differences were apparent, as the METH‐induced decreases in PKA activity and DOPAC content were more evident in male rats. In conclusion, preweanling METH exposure caused changes in DA markers that were still detectable at PD 90; however the magnitude of many of these effects (e.g., the reductions in DA and DOPAC levels) was substantially less than typically reported for rats treated with METH in adulthood. The ability of METH to cause long‐term reductions in PKA activity may partially account for some of behavioral deficits exhibited by rats exposed to METH prior to weaning. Synapse 48:131–137, 2003. © 2003 Wiley‐Liss, Inc.
Direct correlation of collagen matrix deformation with focal adhesion dynamics in living corneal fibroblasts
Authors: Petroll W. Matthew , Ma Lisha , Jester James V. 
Published: March 2003

The purpose of this study was to develop and apply a new model for investigating how the organization and movement of cell-matrix adhesion sites correlate with force generation by corneal fibroblasts on a fibrillar collagen extracellular matrix. Primary cultures of rabbit corneal fibroblasts were transfected using a vector encoding GFP-zyxin to allow visualization of adhesion sites. Cells were plated at low density on top of 100 μm thick fibrillar collagen lattices embedded with 2 μm diameter red fluorescent beads. Time-lapse imaging was performed at one minute intervals for up to 3 hours. At each time interval, GFP-zyxin, bead and DIC images were acquired in rapid succession using filter wheels. Cells were treated with cytochalasin D and/or Triton X-100 at the end of each experiment. The movements of adhesions and nearby matrix landmarks were measured and correlated from the time-lapse digital images, and the size, intensity and orientation of the adhesions were quantified.GFP-zyxin was detected in adhesions of transfected corneal fibroblasts as confirmed using vinculin counterstaining. Time-lapse imaging revealed extensions and retractions of cell processes and displacements of the fiduciary beads that were similar to control cells. Extending processes exhibited the most complex behavior, with new adhesions continuously forming at the leading edge while existing adhesions moved backward in a retrograde fashion. This process generated tractional forces as indicated by pulling in of the extracellular matrix in front of the cell. Interestingly, during extension, adhesions along the ventral surface of the cell body generally moved toward those at the tip, resulting in contractile-like shortening and matrix compression at the base of lamellipodia. Overall, a high correlation was found between both the magnitude (R=0.87, P&lt;0.001) and direction (R=0.98, P&lt;0.001) of the adhesions and nearby matrix displacements. Cytochalasin D induced rapid and reversible disassembly of adhesions, cell elongation and matrix relaxation, including decompression at the base of the lamellipodia. This new experimental model allows direct,dynamic assessment of cell-matrix interactions on a fibrillar collagen matrix. Our results are consistent with the previously described `frontal towing'model of cell motility and demonstrate for the first time that this mechanism is employed by cells interacting with a fibrillar extracellular matrix.
Thermoreversible Self-Organized Gels of a Liquid Crystal Formed by Aggregation of trans-1,2-Bis(acylamino)cyclohexane Containing a Mesogenic Moiety
Authors: Kato Takashi , Kondo Gohta , Hanabusa Kenji 
Published: March 2003

Abstract
A novel class of anisotropic gels has been obtained by the formation of a self-associated molecular network in a liquid crystal. The gels exhibit thermoreversible two gel states derived from liquid-crystalline and isotropic states of the mesogenic molecule.
Development and evaluation of an advanced training technology course within a union‐based industrial emergency response training program
Authors: Fernandez Jennifer A. , Vazquez Luis , Daltuva Judith A. , Robins Thomas G. , Williams Melina 
Published: March 2003

AbstractBackgroundThe Health and Safety Department of the United Automobile Workers recently introduced the use of Advanced Training Technologies (ATTs) into a previously successful Industrial Emergency Response (IER) program. The new curriculum attempted to incorporate web‐based technology, while preserving the historical emphasis on the use of peer trainers and the Small Group Activity Method (SGAM) to promote team problem solving and worker empowerment.MethodsThe University of Michigan evaluated the program by administering a survey combining open‐ and closed‐ended questions to trainees.ResultsOf the 46 respondents, most rated the program very highly, found that the use of internet technology allowed faster access to current information, reported peer trainers as one of program aspects they liked best, and did not find working in groups of three per computer difficult.ConclusionsIt is possible to enhance a workplace health and safety training program through the introduction of ATT without compromising participant‐centered, group learning program philosophies. Am. J. Ind. Med. 43:429–435, 2003. © 2003 Wiley‐Liss, Inc.
Crystallographic report: Crystal structure of a one‐dimensional zinc(II) coordination polymer containing 4,4′‐biphenyldicarboxylate hemihydrate
Authors: Yuan Wei , Long La‐Sheng 
Published: March 2003

AbstractA one‐dimensional zinc(II) coordination polymer has been constructed from zinc(II), 4,4′‐biphenyldicarboxylate and pyridine in which each zinc(II) atom is coordinated by two pyridine ligands and two monodentate 4,4′‐biphenyldicarboxylate ligands that define a distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of all Four Stereoisomers of Leucomalure, Components of the Female Sex Pheromone of the Satin Moth, Leucoma salicis
Authors: Muto Shin‐etsu , Mori Kenji 
Published: March 2003

AbstractLipase PS‐C(Amano)‐catalyzed asymmetric acetylation of (±)‐4‐(tert‐butyldiphenylsilyloxy)‐cis‐2,3‐epoxy‐1‐butanol afforded the (2R,3S)‐epoxy alcohol and the (2S,3R)‐epoxyacetate, which were converted into all of the four stereoisomers of leucomalure [(3Z)‐cis‐6,7‐cis‐9,10‐diepoxy‐3‐henicosene], the female sex pheromone of the Satin moth, Leucoma salicis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Facile distinction of neutral and acidic tetraether lipids in archaea membrane by halogen atom adduct ions in electrospray ionization mass spectrometry
Authors: Murae Tatsushi , Takamatsu Yuichiro , Muraoka Ryohei , Endoh Satoshi , Yamauchi Noriaki 
Published: March 2003

AbstractCalditocaldarchaeol (neutral tetraether lipid) from Sulfolobus acidocaldarius (acidothermophilic archaea) and intact total lipid from the thermoacidophilic archaea Sulfolobus sp. was examined by electrospray ionization time‐of‐flight mass spectrometry in the negative‐ion mode using high resolution. When the sample was injected as a solution in a 3 : 1 mixture of methanol (MeOH) and chloroform (CHCl3) using an infusion system, the total ether lipid afforded molecular‐related ions as [M − H]− for acidic polar lipids containing a phosphoric or sulfuric group, and as [M + Cl]− ion for neutral glycolipids. The attachment of chloride was confirmed by the observation of [M + Br]− ion, instead of [M + Cl]− ion, when a 3 : 1 mixture of MeOH and CHBr3 was used in place of MeOH–CHCl3 as the solvent. The composition of tetraether neutral glycolipids that are different from each other only in the number of five‐membered rings in the isoprenoid chain was determined on the basis of the isotope‐resolved mass spectrum of [M + Cl]− ions. As for acidic tetraether lipids, molecular‐related ions [M − H]−) were not observed when the 3 : 1 MeOH–CHBr3 mixture was used as the solvent. These results together afforded a facile method of distinguishing neutral from acidic tetraether lipids in intact total lipids of acidothermophilic archaea. This method was applied to determine the difference of the number of five‐membered rings in isoprenyl chains of neutral tetraether glycolipids yielded by the Sulfolobus sp. grown at different temperatures. Discrimination of neutral tetraether glycolipids from acidic tetraether lipids in the total lipids obtained from Thermoplasma sp. was also achieved by this method. Copyright © 2002 John Wiley & Sons, Ltd.
L‐phenylalanine selectively depresses currents at glutamatergic excitatory synapses
Authors: Glushakov A.V. , Dennis D.M. , Sumners C. , Seubert C.N. , Martynyuk A.E. 
Published: March 2003

AbstractTo explore the hypothesis that L‐phenylalanine (L‐Phe) depresses glutamatergic synaptic transmission and thus contributes to brain dysfunction in phenylketonuria (PKU), the effects of L‐Phe on spontaneous and miniature excitatory postsynaptic currents (s/mEPSCs) in rat and mouse hippocampal and cerebrocortical cultured neurons were studied using the patch‐clamp technique. L‐Phe depressed the amplitude and frequency of both N‐methyl‐D‐aspartate (NMDA) and non‐NMDA components of glutamate receptor (GluR) s/mEPSCs. The IC50 of L‐Phe to inhibit non‐NMDAR mEPSC frequency was 0.98 ± 0.13 mM, a brain concentration seen in classical PKU. In contrast, D‐Phe had a significantly smaller effect, whereas L‐leucine, an amino acid that competes with L‐Phe for brain transporter, had no effect on mEPSCs. Unlike GluR s/mEPSCs, GABA receptor mIPSCs were not attenuated by L‐Phe. A high extracellular concentration of glycine prevented the attenuation by L‐Phe of NMDAR current, activated by exogenous agonist, and of NMDAR s/mEPSC amplitude, but not of NMDAR s/mEPSC frequency. On the other hand, L‐Phe significantly depressed non‐NMDAR current activated by low but not high concentrations of exogenous agonists. Glycine‐independent attenuation of NMDAR s/mEPSC frequency suggests decreased presynaptic glutamate release caused by L‐Phe, whereas decreased amplitudes of NMDAR and non‐NMDAR s/mEPSCs are consistent with competition of L‐Phe for the glycine‐ and glutamate‐binding sites of NMDARs and non‐NMDARs, respectively. The finding that GluR activity is significantly depressed at conditions characteristic of classical PKU indicates a potentially important contribution of impaired GluR function to PKU‐related mental retardation and provides important insights into the potential physiological consequences of impaired GluR function. © 2003 Wiley‐Liss, Inc.
Mixed FEM and BEM coupling for the three‐dimensional magnetostatic problem
Authors: Daveau C. , Menad M. 
Published: March 2003

AbstractWe present two new mixed finite element methods coupled with a boundary method for the three dimensional magnetostatic problem. Such formulations are obtained by coupling a finite element method inside a bounded domain with a boundary integral method involving either the Calderon equations or the inverse of Dirichlet Neumann operator to treat the exterior domain. First, we present the formulations and then prove that our mixed formulations are well posed and that they lead to a convergent Galerkin method. Finally, we give numerical results for a sphere immersed in a homogeneous (source) field in the two formulations. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 443–462, 2003
Error estimate and regularity for the compressible Navier‐Stokes equations by Newton's method
Authors: Kim Sang Dong , Lee Yong Hun 
Published: March 2003

AbstractThe finite element discretization error estimate and H1 regularity are shown for the solution generated by Newton's method to the stationary compressible Navier‐Stokes equations by interpreting Newton's method as an equivalent iterative method. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 511–524, 2003
Hydrolysis of Schiff Bases Promoted by UV Light
Authors: Huang Zhaohua , Wan Decheng , Huang Junlian 
Published: March 2003

Abstract
The first hydrolysis of Schiff base under 365 nm UV light is reported. The reaction was affected markedly by the solvent used. It has been successfully applied to the synthesis of compound 2c which is a useful antitumor agent.
Tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP): A Novel Catalyst for Selective Deacetylation
Authors: Yoshimoto Kazuya , Kawabata Hirotoshi , Nakamichi Natsuki , Hayashi Masahiko 
Published: March 2003

Abstract
Chemo- and stereoselective deacetylation was achieved by the use of a catalytic amount of tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
Occupational health services at ten U.S. Department of Energy weapons sites
Authors: Salazar Mary K. , Takaro Timothy K. , Gochfeld Michael , Barnhart Scott 
Published: March 2003

AbstractBackgroundNuclear weapons sites are among thousands of federal facilities that are contaminated with a variety of hazardous wastes. Workers at these sites participate in a wide array of activities that can result in their exposure to a variety of hazards.MethodsThe purpose of this study was to describe the occupational health and safety services at ten U.S. Department of Energy sites. Interviews were conducted with 30 health and safety professionals, including physicians, program managers, and industrial hygienists. Data collection was guided by a quality assessment model that provided a means to examine the structures, processes, and outcomes of occupational health and safety services.ResultsIt was determined that services for some worker groups, such as subcontractors, were limited; other problems identified included a mismatch between hazards (physical hazards) and types of service providers (radiation experts), ineffective databases, and communication problems.ConclusionsThis description of health and safety services has provided valuable information that can be used to improve the efficiency and effectiveness of service delivery in this large and complex organization. Am. J. Ind. Med. 43:418–428, 2003. © 2003 Wiley‐Liss, Inc.
Historic review:Frederick Challenger, 1887–1983: chemist and biochemist
Authors: Chasteen Thomas G. , Bentley Ronald 
Published: March 2003

AbstractFrederick Challenger (1887–1983) lived a long life as a chemist and biochemist. He received a PhD for work with O. Wallach at the University of Göttingen in 1912 and a DSc from the University of Birmingham in 1920. After positions at Birmingham, UK, and Manchester, UK, he became Professor of Organic Chemistry at the University of Leeds, UK, in 1930, remaining as Head of the Department until 1953, when he retired as Emeritus Professor. He continued with scientific activity, publishing his final paper in 1978. Much of his work concerned the biological methylation of metalloids such as arsenic, selenium, and tellurium. He determined precise chemical structures for the methylated products and he established a role for adenosylmethionine in the process. An important finding was that the sulfonium compound, (CH3)2S+CH2CH2COO−, was present in several algae and on decomposition led to production of dimethylsulfide. This sulfonium compound was the first of this class to be found in a plant. He had many other wide‐ranging interests, including the organic chemistry of compounds of bismuth and thallium. Copyright © 2003 John Wiley & Sons, Ltd.
Electrochemically reduced tungsten‐based active species as catalysts for cross‐metathesis reactions: cross‐metathesis of non‐functionalized olefins
Authors: Çetinkaya Sevil , Düz Bülent , İmamog̃lu Yavuz 
Published: March 2003

AbstractThe electrochemical reduction of WCl6 results in the formation of an active olefin (alkene) metathesis catalyst. The application of the WCl6–e−–Al–CH2Cl2 catalyst system to cross‐metathesis reactions of non‐functionalized acyclic olefins is reported. Undesirable reactions, such as double‐bond shift isomerization and subsequent metathesis, were not observed in these reactions. Cross‐metathesis of 7‐tetradecene with an equimolar amount of 4‐octene generated the desired cross‐product, 4‐undecene, in good yield. The reaction of 7‐tetradecene with 2‐octene, catalyzed by electrochemically reduced tungsten hexachloride, resulted in both self‐ and cross‐metathesis products. The cross‐metathesis products, 2‐nonene and 6‐tridecene, were formed in larger amounts than the self‐metathesis products of 2‐octene. The optimum catalyst/olefin ratio and reaction time were found to be 1 : 60 and 24 h, respectively. The cross‐metathesis of symmetrical olefins with α‐olefins was also studied under the predetermined conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Recent Developments in the Isonitrile‐Based Multicomponent Synthesis of Heterocycles
Authors: Zhu Jieping 
Published: March 2003

AbstractAlthough the synthesis of β‐lactams by means of tethered Ugi reactions has been known since the early 1960s, the 1995 report from Ugi’s group could be regarded as a turning point in the development of novel multicomponent reactions (MCRs) for heterocycle syntheses. Indeed, the number of articles describing isocyanide‐based multicomponent syntheses of heterocycles has increased steadily since then. Although most of these novel MCRs still exploit the archetypal reactivity of isocyanide, its pronounced ability to undergo α‐addition with electrophiles (sp2‐ and sp‐carbon atoms) and nucleophiles, new MCRs have also been discovered as a consequence of exploiting the different secondary reactions of this α‐adduct. Since most of these MCRs were devised on the basis of known bimolecular reactions, judicious combination of reactive functional groups within substrates is of fundamental importance. While the combinatorial principle can help in finding and exploring new MCRs, we would advocate a “substrate‐design approach” in searching for novel MCRs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
S‐100 proteins in the human peripheral nervous system
Authors: Gonzalez‐Martinez T. , Perez‐Piñera P. , Díaz‐Esnal B. , Vega J.A. 
Published: March 2003

AbstractThis article reviews the distribution of S100 proteins in the human peripheral nervous system. The expression of S100 by peripheral glial cells seems to be a distinctive fact of these cells, independently of their localization and their ability to myelinate or not. S100 proteins expressing cells include satellite cells of sensory, sympathetic and enteric ganglia, supporting cells of the adrenal medulla, myelinating and non‐myelinating Schwann cells in the nerve trunks, and the Schwann‐related cells of sensory corpuscles. In addition, S100 proteins are expressed in peripheral neurons. Most of them express S100α protein, and a subpopulation of sensory neurons in dorsal root ganglia contains S100β protein or S100α plus S100β proteins. Microsc. Res. Tech. 60:633–638, 2003. © 2003 Wiley‐Liss, Inc.
Upregulation of catecholamine biosynthetic enzymes by nitric oxide
Authors: Kim Donghou , Choi Hyun Jin , Kim Seong Who , Cho Sung‐Woo , Hwang Onyou 
Published: March 2003

AbstractNitric oxide (NO) is recognized as an essential intercellular messenger in central and peripheral nervous systems. In the present study, whether NO exerts effects on catecholamine (CA) biosynthetic enzymes was determined in primary cultured bovine chromaffin cells. The NO generators sodium nitroprusside (SNP) and S‐nitroso‐N‐acetyl‐D,L‐penicillamine, in a dose‐dependent manner, upregulated transcript levels of tyrosine hydroxylase, dopamine β‐hydroxylase, and phenylethanolamine N‐methyltransferase, accompanied by long‐term increases in their enzyme activities and the intracellular CA levels. The SNP effect was diminished by co‐treatment with LY83583, an inhibitor of soluble guanylate cyclase, or H‐8, a cyclic GMP (cGMP)‐dependent protein kinase inhibitor. Co‐treatment with 8‐Br‐cGMP did not increase further the expression of these enzyme genes induced by SNP. Taken together, the data suggest that NO leads to long‐term upregulation of the CA system via induction of the genes involved and that this is mediated by cGMP‐dependent signaling pathway. © 2003 Wiley‐Liss, Inc.
Radiation Crosslinking of Poly(ethylene‐co‐octene) with Electron Beam Radiation
Authors: Perraud Sophie , Vallat Marie‐France , Kuczynski Jerzy 
Published: March 2003

AbstractFilms of ethylene‐co‐octene copolymer are irradiated in air after moulding between Mylar® films with electron beam at different doses. To correlate the change in structure with properties, the irradiated and unirradiated samples are characterised by FTIR spectroscopy, swelling and mechanical measurements. Obtained changes are dependant on the radiation dose of the incident electron beam. Irradiation induces trans‐vinylene double bonds detected by FTIR spectroscopy in transmission mode. No hydroxyl (OH) and carbonyl (CO) groups were recorded by FTIR spectroscopy. More drastic changes are observed with swelling method and by mechanical properties showing the crosslinking effect. Based on the results obtained by analytical techniques used in this study, free radicals mechanism involving mainly the pendant chains of the PE‐co‐O is proposed.Strain at break versus gel fraction.magnified imageStrain at break versus gel fraction.
Pushout with virtual thresholds buffer management scheme in a shared buffer ATM switch
Authors: Yang Ruey‐Bin , Chu Yuan‐Sun , Wu Cheng‐Shong , Liang Ming‐Cheng 
Published: March 2003

AbstractIn this paper we investigate the performance metrics of buffer management schemes. In general, the selective pushout (SP) scheme can support very low loss probability of the high‐priority cells, but it may cause unfairness of buffer allocation among different output queues and high overall cell loss probability. In order to fit the dynamic required performance metrics of ATM switches, a novel buffer management scheme called pushout with virtual thresholds (PVT) is proposed. In the PVT scheme, each output queue is guaranteed to increase in length until its virtual threshold (VT). Simulation results show the PVT can dynamically achieve the fairness and low overall cell loss probability or very low loss probability of the high priority cells by adequately adjusting the VT. Specially, when the VT = 0, the PVT control can be viewed as the SP control. Copyright © 2003 John Wiley & Sons, Ltd.