bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy–architectural patterns among the five‐ to twelve‐vertex closo‐carboranes
Authors: Williams Robert E. , Bausch Joseph W. 
Published: May 2003

AbstractIn 1969 the order of stabilities of all possible neutral two‐carbon closo‐carboranes, i.e. from closo‐C2B3H5 to closo‐C2B10H12, was forecast. It was wistfully anticipated that all 52 skeletal structures would be based solely upon the most spherical deltahedra (polyhedra consisting exclusively of triangular faces, closo‐n〈III〉; n = 5 to 12) and that the order of stabilities would be based upon the presumed preference of the two carbon atoms to occupy (a) low‐coordinated and (b) nonadjacent sites.The 52 potential isomers reduce to 42 isomers upon optimization (using the DFT B3LYP/6‐311G* level of theory and the Gaussian 94 program), as seven isomers rearrange spontaneously into more stable isomers and three isomers rearrange spontaneously into two structures incorporating four‐membered open faces within which are accommodated both carbon atoms, in adjacent 4k‐edge sites. The order of stability of the ‘surviving’ 42 closo‐carborane configurations comports nicely with the 1969 projections with the exception of three intimately related closo‐11 vertex isomers. An explanation for the marginally increased stability of these three intimately related closo‐11 vertex isomers is offered. For the remaining 39 isomers, the differences, between the calculated and estimated stability values, seldom exceed 6 kcal mol−1. Copyright © 2003 John Wiley & Sons, Ltd.
Condensed polyhedral boranes and analogous organometallic clusters: a molecular orbital and density functional theory study on the cap–cap interactions
Authors: Jemmis Eluvathingal D. , Pancharatna Pattath D. 
Published: May 2003

AbstractThe interactions between the non‐bonded atoms on adjacent units were assumed to be one of the major factors that hinder the exploration and advancement of macropolyhedral borane chemistry. In sandwich complexes involving boron as the bridging atom, the interaction between non‐bonded atoms tends to be antibonding, but a closer analysis of various condensed systems shows that this cannot be generalized. The overlap populations (OPs) calculated for structures optimized at the B3LYP/6‐31g* level [B21H181− (5), B20H16 (6), [Al(C2B4H6)2]1− (7), B12H102− (8), B10H82− (9 and 14), B11H13 (10), B10H14 (11), C2B8H12 (13) and B20H182− (15)] indicate bonding interactions between the caps, except for 7 and 13. This is substantiated by a detailed extended Hückel‐based molecular orbital (MO) study using B10H14 as a model system to represent macropolyhedral boranes with higher fusions. An isolobal equivalent structure, [C8H6(Ru(CO)2Me)2] (17), studied at the B3LYP/LANL2DZ level has weak RuRu interactions. An analysis of the nature of the MOs in B10H14 (11) shows that there is no direct head on overlap of the cap orbitals that are antibonding; this is in contradiction to sandwiched molecules (7), where there are two occupied MOs with antibonding interactions. The m + n + o electron pair count (m is the number of cages involved in condensation, n is the number of vertices and o is the number of single vertex condensations) of sandwich complexes requires the filling of these two MOs. The negative OP between the carbon atoms in 13 is attributed to the greater electronegativity of carbon and is substantiated by a fragment MO analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Radial basis functions for solving near singular Poisson problems
Authors: Chen C. S. , Kuhn G. , Li J. , Mishuris G. 
Published: May 2003

AbstractIn this paper, we investigate the use of radial basis functions for solving Poisson problems with a near‐singular inhomogeneous source term. The solution of the Poisson problem is first split into two parts: near‐singular solution and smooth solution. A method for evaluating the near‐singular particular solution is examined. The smooth solution is further split into a particular solution and a homogeneous solution. The MPS‐DRM approach is adopted to evaluate the smooth solution. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of gain versus loss and certain versus probable outcomes on social value orientations
Authors: Poppe Matthijs , Valkenberg Huib 
Published: May 2003

AbstractIn an experiment, the effects of types of outcomes on social value orientations (individualism, competition, pro‐social orientation) were investigated. Ninety‐nine students made 28 choices which affected outcomes (points to be converted into money) for themselves and another (unknown) person. About half of them started out with nothing but they could allocate positive outcomes (gains) to themselves and/or the other. The other half were told that they themselves and another person would start out with some outcomes but they could lose outcomes depending on the choices. For about half the participants it was certain that their choices would result in outcomes while for the other half outcomes would be likely rather than certain. The expected utility of the outcomes was the same in the four conditions. In accordance with prospect theory, it was expected and found that participants would be more individualistic in the conditions with losses than in the conditions with gains. In accordance with social comparison theory, it was expected and found that participants would be more competitive in the conditions with probable outcomes than in the conditions with certain outcomes. Copyright © 2002 John Wiley & Sons, Ltd.
The influence of approach and avoidance motor actions on food intake
Authors: Förster Jens 
Published: May 2003

AbstractTwo experiments explored the effect of arm positions of approach and avoidance on food intake. In Experiment 1, arm extension, an expression of avoidance behavior, led to smaller food intake than arm flexion, an expression of approach behavior. In Experiment 2, this effect was found only for a delicious drink (i.e. orange juice), but not for a neutral drink (lukewarm water). Different theoretical accounts for explaining the findings are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Sox18 mutations in the ragged mouse alleles ragged‐like and opossum
Authors: James Kristy , Hosking Brett , Gardner Jennifer , Muscat George E.O. , Koopman Peter 
Published: May 2003

AbstractSummary: The ragged (Ra) spontaneous mouse mutant is characterised by abnormalities in its coat and cardiovascular system. Four alleles are known and we have previously described mutations in the transcription factor gene Sox18 in the Ra and RaJ alleles. We report here Sox18 mutations in the remaining two ragged alleles, opossum (Raop) and ragged‐like (Ragl). The single‐base deletions cause a C‐terminal frameshift, abolishing transcriptional trans‐activation and impairing interaction with the partner protein MEF2C. The nature of these mutations, together with the near‐normal phenotype of Sox18‐null mice, suggests that the ragged mutant SOX18 proteins act in a dominant‐negative fashion. The four ragged mutants represent an allelic series that reveal SOX18 structure–function relationships and implicate related SOX proteins in cardiovascular and hair follicle development. genesis 36:1–6, 2003. © 2003 Wiley‐Liss, Inc.
Tolerance to the memory disruptive effects of cannabinoids involves adaptation by hippocampal neurons
Authors: Hampson Robert E. , Simeral John D. , Kelly Erica J. , Deadwyler Sam A. 
Published: May 2003

AbstractThe effects of chronic exposure to cannabinoids on short‐term memory in rats were assessed during repeated daily injections of an initially debilitating dose (3.75 mg/kg) of the potent CB1 cannabinoid receptor ligand, WIN 55,212‐2. Delayed nonmatch to sample (DNMS) performance was assessed over a 35‐day exposure period in which performance was initially disrupted during the first 21 days of exposure but recovered by day 30 and was stable at pre‐drug levels for 5 days thereafter. Withdrawal was precipitated by injections of the CB1 receptor antagonist SR141716A and transiently reduced performance for 2 days but was restabilized to pre‐drug levels within 3–4 days. Concomitant recording from identified CA1 and CA3 hippocampal neurons demonstrated a marked correspondence in the time course of suppression of peak firing in the sample and delay phases of the task to the drug‐induced performance deficits over the same days of exposure. Hippocampal encoding of task‐relevant events and performance levels “tracked” each other on a daily basis throughout the chronic cannabinoid treatment and withdrawal regimen. However, hippocampal neuronal activity in the nonmatch phase of the task was unaffected by the chronic cannabinoid treatment or withdrawal, suggesting that only a select population of hippocampal neurons and synapses are involved in cannabinoid‐sensitive short‐term memory processes. Hippocampus 2003;13:543–556. © 2003 Wiley‐Liss, Inc.
Downregulation of the α5 subunit of the GABAA receptor in the pilocarpine model of temporal lobe epilepsy
Authors: Houser Carolyn R. , Esclapez Monique 
Published: May 2003

AbstractSpecific subunits of γ‐aminobutyric acid (GABA)A receptors may be regulated differentially in animal models of temporal lobe epilepsy during the chronic stage. Although several subunits may be upregulated, other subunits may be downregulated in the hippocampal formation. The α5 subunit is of particular interest because of its relatively selective localization in the hippocampus and its potential role in tonic inhibition. In normal rats, immunolabeling of the α5 subunit was high in the dendritic layers of CA1 and CA2 and moderate in these regions of CA3. In chronic pilocarpine‐treated rats displaying recurrent seizures, α5 subunit‐labeling was substantially decreased in CA1 and nearly absent in CA2. Only slight decreases in immunolabeling were evident in CA3. In situ hybridization studies demonstrated that the α5 subunit mRNA was also strongly decreased in stratum pyramidale of CA1 and CA2. Thus, the alterations in localization of the α5 subunit peptide and its mRNA were highly correlated. The large decreases in labeling of the α5 subunit did not appear to be related to loss of pyramidal neurons in CA1 or CA2 since these neurons were generally preserved in pilocarpine‐treated animals. No comparable decreases in labeling of the α2 subunit of the GABAA receptor were detected. These findings indicate that the α5 subunit of the GABAA receptor is capable of substantial and prolonged downregulation in remaining pyramidal neurons in a model of temporal lobe epilepsy. The results raise the possibility that presumptive extrasynaptic GABAA receptor subunits, such as the α5 subunit, may be regulated differently than synaptically located subunits, such as the α2 subunit, within the same brain regions in some pathological conditions. Hippocampus 2003;13:633–645. © 2003 Wiley‐Liss, Inc.
Rapid induction of BDNF expression in the hippocampus during immobilization stress challenge in adult rats
Authors: Marmigère Frédéric , Givalois Laurent , Rage Florence , Arancibia Sandor , Tapia‐Arancibia Lucia 
Published: May 2003

AbstractBrain‐derived neurotrophic factor (BDNF) is strongly expressed in the hippocampus, where it has been associated with memory processes. In the central nervous system, some learning processes, as well as brain insults, including stress, induce modifications in BDNF mRNA expression. Because stress and memory appear to share some neuronal pathways, we studied BDNF mRNA and BDNF peptide variations in response to short times of immobilization stress. Using an RNase protection assay, we demonstrated that short‐time stress application induced a significant increase (at 60 min) in BDNF mRNA levels in the whole rat hippocampus. Changes in BDNF mRNA content appear to reflect increased expression of BDNF transcripts containing exons I, II, and III, that were also significantly modified at this time. The time course of stress‐induced changes in BDNF transcript levels revealed that mRNA containing exon III was the first increased, significantly elevated by 15 min, attaining maximal levels at 60 min, as BDNF transcripts containing exons I and II. However, at longer times of stress (180 min), BDNF mRNA levels were decreased as well as mRNA containing exon IV. In situ hybridization analysis of discrete hippocampal layers demonstrated that BDNF mRNA expression increased as early as 15 min in most hippocampal regions, with no modification in the number of labeled cells. The same signal pattern, although less pronounced, was determined at 60 min, but at this time a significant increase in BDNF‐positive cells was visualized in the CA3 layer. The peptide, measured by immunoassay, was significantly augmented after 180 min of stress exposure whereas at 300 min, levels were similar to those measured in control animals. These data suggest that rapid changes in BDNF expression may be part of a compensatory response to preserve hippocampal homeostasis or a form of neuronal plasticity to cope with new stimuli. Hippocampus 2003;13:646–655. © 2003 Wiley‐Liss, Inc.
Neuropeptide Y delays hippocampal kindling in the rat
Authors: Reibel Sophie , Benmaamar Ramla , Lê Bich Thuy , Larmet Yves , Kalra Satya P. , Marescaux Christian , Depaulis Antoine 
Published: May 2003

AbstractChronic intrahippocampal infusion of the neurotrophin brain‐derived neurotrophic factor (BDNF) has been shown to delay kindling epileptogenesis in the rat and several lines of evidence suggest that neuropeptide Y could mediate these inhibitory effects. Chronic infusion of BDNF leads to a sustained overexpression of neuropeptide Y in the hippocampus, which follows a time course similar to that of the suppressive effects of BDNF on kindling. In vivo, acute applications of neuropeptide Y or agonists of its receptors exert anticonvulsant properties, especially on seizures of hippocampal origin. In this study, we examined how chronic infusion of this neuropeptide in the hippocampus affected kindling epileptogenesis. A 7‐day continuous infusion of neuropeptide Y in the hippocampus delayed the progression of hippocampal kindling in the rat, whereas anti‐neuropeptide Y immunoglobulins had an aggravating effect. These results show that neuropeptide Y exerts anti‐epileptogenic properties on seizures originating within the hippocampus and lend support to the hypothesis that BDNF delays kindling at least in part through upregulation of this neuropeptide. They also suggest that the seizure‐induced upregulation of neuropeptide Y constitutes an endogenous mechanism counteracting excessive hippocampal excitability. Hippocampus 2003;13:557–560. © 2003 Wiley‐Liss, Inc.
Age‐related differences in the functional connectivity of the hippocampus during memory encoding
Authors: Grady Cheryl L. , McIntosh Anthony R. , Craik Fergus I.M. 
Published: May 2003

AbstractThe purpose of the current experiment was to examine the functional connectivity of the hippocampus during encoding in young and old adults, and the way in which this connectivity was related to recognition performance. Functional connectivity was defined as the correlation between activity in the hippocampus and activity in the rest of the brain, as measured by neuroimaging. During encoding of words and pictures of objects in young adults, hippocampal activity was correlated with activity in the ventral prefrontal and extrastriate regions, and increased activity in all these regions was associated with better recognition. In contrast, older adults showed correlations between hippocampal activity and the dorsolateral prefrontal and parietal regions, and positive correlations between activity in these regions and better memory performance. This ventral/dorsal distinction suggests a shift in the cognitive resources used with age from more perceptually based processes to those involved in executive and organizational functions. The results of this study provide evidence that aging is associated with alterations in hippocampal function, including how it is functionally connected with prefrontal cortex, and that these alterations have an impact on memory performance. Hippocampus 2003;13:572–586. © 2003 Wiley‐Liss, Inc.
Effects of deep hypothermia on nitric oxide‐induced cytotoxicity in primary cultures of cortical neurons
Authors: Varathan Sriranganathan , Shibuta Satoshi , Varathan Vidya , Takemura Motohide , Yonehara Norifumi , Mashimo Takashi 
Published: May 2003

AbstractNitric oxide (NO) is thought to play a major role during cerebral ischemia. However, the protective efficacy of hypothermia against NO‐induced neurotoxicity remains to be examined. In the present study, the degree of neurotoxicity induced by NO was analyzed in two temperature groups (normothermia, 37°C; deep hypothermia, 22°C) of cultured E16 Wistar rat cortical neurons. Two different NO donors, 1‐hydroxy‐2‐oxo‐3‐(N‐ethyl‐2‐aminoethyl)‐3‐ethyl‐1‐triazene (NOC‐12) and 1‐hydroxy‐2‐oxo‐3‐(3‐amynopropyl)‐3‐isopropyl‐1‐triazene (NOC‐5), that have equal half‐lives at 37°C and 22°C, respectively, were used. Cultured neurons in each temperature group were exposed to 30 and 100 μM NOC for three different time courses, 6 hr, 12 hr, and 24 hr. The survival rates of neurons were evaluated by assessing viable neurons on photomicrographs before and after the experiments. The highest survival rate (approximately 93%) was seen in both temperature groups when neurons were exposed to 30 μM NOC for 6 hr and 12 hr, and there was no significant difference observed between these two groups (P > 0.05). Almost equal survival rates were observed in both temperature groups following exposure to 30 μM NOC for 24 hr (at 37°C, 80.4% ± 2.6%; at 22°C, 83.2% ± 1.6%; P > 0.05). During exposure to 100 μM NOC, although the survival rate linearly decreased (approximately from 70% to 5%) in both temperature groups when exposed for 6–24 hr, there were no significant intergroup differences observed (P > 0.05). In conclusion, hypothermia does not provide adequate protection to the neurons by acting on the mechanisms evoked by NO, so we speculate that hypothermia may not confer neuroprotetcion once NO is released during ischemia. © 2003 Wiley‐Liss, Inc.
Effect of antipsychotic drugs on brain‐derived neurotrophic factor expression under reduced N‐methyl‐D‐aspartate receptor activity
Authors: Fumagalli Fabio , Molteni Raffaella , Roceri Mila , Bedogni Francesco , Santero Raffaella , Fossati Claudia , Gennarelli Massimo , Racagni Giorgio , Riva Marco Andrea 
Published: May 2003

AbstractBrain‐derived neurotrophic factor (BDNF) promotes a variety of neuromodulatory processes during development as well as in adulthood. This neurotrophin has been associated with synaptic plasticity, suggesting that its regulation may represent one of the mechanisms through which psychotropic drugs alter brain function. Because reduced glutamatergic function represents a major feature of schizophrenia, we investigated the effects of the concomitant administration of haloperidol or olanzapine with the N‐methyl‐D‐aspartate (NMDA) receptor antagonist MK‐801 on BDNF expression. MK‐801 reduces the hippocampal expression of the neurotrophin; this effect was exacerbated by haloperidol, but it was normalized by olanzapine. Our data reveal a fine tuning of BDNF biosynthesis and a differential modulation by antipsychotic drugs when NMDA‐mediated transmission is reduced, suggesting that haloperidol and olanzapine can produce different effects on brain plasticity through the modulation of BDNF expression. © 2003 Wiley‐Liss, Inc.
Glucagon‐like peptide‐1 decreases endogenous amyloid‐β peptide (Aβ) levels and protects hippocampal neurons from death induced by Aβ and iron
Authors: Perry TracyAnn , Lahiri Debomoy K. , Sambamurti Kumar , Chen Demao , Mattson Mark P. , Egan Josephine M. , Greig Nigel H. 
Published: May 2003

AbstractGlucagon‐like peptide‐1(7–36)‐amide (GLP‐1) is an endogenous insulinotropic peptide that is secreted from the gastrointestinal tract in response to food. It enhances pancreatic islet β‐cell proliferation and glucose‐dependent insulin secretion and lowers blood glucose and food intake in patients with type 2 diabetes mellitus. GLP‐1 receptors, which are coupled to the cyclic AMP second messenger pathway, are expressed throughout the brains of rodents and humans. It was recently reported that GLP‐1 and exendin‐4, a naturally occurring, more stable analogue of GLP‐1 that binds at the GLP‐1 receptor, possess neurotrophic properties and can protect neurons against glutamate‐induced apoptosis. We report here that GLP‐1 can reduce the levels of amyloid‐β peptide (Aβ) in the brain in vivo and can reduce levels of amyloid precursor protein (APP) in cultured neuronal cells. Moreover, GLP‐1 and exendin‐4 protect cultured hippocampal neurons against death induced by Aβ and iron, an oxidative insult. Collectively, these data suggest that GLP‐1 can modify APP processing and protect against oxidative injury, two actions that suggest a novel therapeutic target for intervention in Alzheimer's disease. © 2003 Wiley‐Liss, Inc.
Myelination and motor coordination are increased in transferrin transgenic mice
Authors: Saleh Maria‐Carla , Espinosa de los Monteros Araceli , de Arriba Zerpa Gonzalo A. , Fontaine Isabelle , Piaud Oriane , Djordjijevic Dragan , Baroukh Nadine , Otin Angel Luis Garcia , Ortiz Esteban , Lewis Sandra , Fiette Laurence , Santambrogio Paolo , Belzung Catherine , Connor James R. , de Vellis Jean , Pasquini Juana M. , Zakin Mario M. , Baron Bruno , Guillou Florian 
Published: May 2003

AbstractMyelin deficiency in the central nervous system (CNS) can cause severe disabling conditions. Most of the transgenic mice models overexpressing myelin components have limitations for investigators of myelin deficiency and myelin therapy as they severely alter CNS architecture. It has been postulated that transferrin (Tf) is involved in oligodendrocyte (OL) maturation and myelinogenesis. Because Tf is not an intrinsic myelin constituent, we decided to investigate if its overexpression could have an impact on the myelination process without affecting myelin integrity. We generated transgenic mice containing the complete human Tf gene specifically overexpressed in OLs. This overexpression leads to more than a 30% increase in myelin components, such as galactolipids, phospholipids, and proteins. Electron microscopy showed that myelin is structurally normal in terms of thickness and compaction. Behavior analysis showed that mice do not display significant modifications in their locomotion and cognitive and emotional abilities. Furthermore, in one of the genetic background, animals presented a significant increase in motor coordination. We did not find any modification in OL number during early postnatal development, suggesting that Tf does not act on OL proliferation. In addition, the levels of iron and ferritin remained unchanged in the brain of transgenic mice compared to control mice. Our findings indicate that, besides its known iron transport function, Tf is able to influence myelination process and induce behavioral improvements in mice. © 2003 Wiley‐Liss, Inc.
Planar inverted‐F antenna with a bent meandered radiating arm for GSM/DCS operation
Authors: Teng Pey‐Ling , Chiou Tzung‐Wern , Wong Kin‐Lu 
Published: May 2003

AbstractAn innovative dual‐frequency planar inverted‐F antenna (PIFA) mounted at the bottom end of the ground plane of a folder‐type mobile handset is presented. The proposed PIFA has a bent meandered radiating arm and is first printed on a flexible printed circuit board (FPCB), which is then bent by 90° and attached to and supported by a foam base of size 40 × 8 × 7 mm3. The proposed PIFA is capable of GSM/DCS operation, and the experimental results of a constructed prototype are presented and discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 73–75, 2003