bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Hepatic Venous Pressure Gradient on the Prediction of Survival of Patients With Cirrhosis in the MELD Era *
Authors: Ripoll Cristina , Bañares Rafael , Rincón Diego , Catalina María-Vega , Lo Iacono Oreste , Salcedo Magdalena , Clemente Gerardo , Núñez Oscar , Matilla Ana , Molinero Luis-Miguel
Published: September 2005

Measurements of portal pressure, usually obtained via the hepatic venous pressure gradient (HVPG) may be a prognostic marker in cirrhosis. The aim of this study was to evaluate the impact of HVPG on survival in patients with cirrhosis in addition to the Model for End-Stage Liver Disease (MELD) score. We also examined whether inclusion of HVPG in a model with MELD variables improves its prognostic ability. Retrospective analyses of all patients who had HVPG measurements between January 1998 and December 2002 were considered. Proportional hazards Cox models were developed. Prognostic calibrative and discriminative ability of the model was evaluated. In this period, 693 patients had a hepatic hemodynamic study, and 393 patients were included. Survival was significantly worse in those patients with greater HVPG value (univariate HR, 1.05; 95% CI, 1.02-1.08;

P

= .001). HVPG remained as an independent variable in a model adjusted by MELD, ascites, encephalopathy, and age (multivariate HR, 1.03; 95% CI, 1.00-1.06;

P

= .05) so that each 1-mmHg increase in HVPG had a 3% increase in death risk. In addition, HVPG as well as MELD score variables and age, significantly contributes to the calibrative predictive capacity of the prognostic model; however, discriminative ability improved only slightly (overall C statistic [95% CI]; MELD score variables: 0.71 [0.62-0.80], MELD score variables, age, and HVPG 0.76: [0.69-0.83]).
In conclusion
, HVPG has an independent effect on survival in addition to the MELD score. Although inclusion of HVPG and age in a survival predicting model would improve the calibrative ability of MELD, its discriminative ability is not significantly improved. (Hepatology 2005;42:793–801.)
Steatohepatitis Induced by Intragastric Overfeeding in Mice *
Authors: Deng Qing-gao , She Hongyun , Cheng Jason H. , French Samuel W. , Koop Dennis R. , Xiong Shigang , Tsukamoto Hidekazu
Published: September 2005

Nonalcoholic steatohepatitis is prevalent among obese individuals with excessive caloric intake, insulin resistance, and type II diabetes. However, no animal models exist that recapitulate this important association. This study produced and characterized steatohepatitis (SH) caused by intragastric overfeeding in mice. C57BL/6, tumor necrosis factor (TNF) type I receptor–deficient, and genetically matched wild type mice were fed via an implanted gastrostomy tube a high-fat diet for 9 weeks in the increasing amount up to 85% in excess of the standard intake. Animals were examined for weight gain, insulin sensitivity, and histology and biochemistry of liver and white adipose tissue (WAT). Overfed C57BL/6 mice progressively became obese, with 71% larger final body weights. They had increased visceral WAT, hyperglycemia, hyperinsulinemia, hyperleptinemia, glucose intolerance, and insulin resistance. Of these mice, 46% developed SH with increased plasma alanine aminotransferase (121 ± 27 vs. 13 ± 1 U/L), neutrophilic infiltration, and sinusoidal and pericellular fibrosis. Obese WAT showed increased TNFα and leptin expression and reciprocally reduced adiponectin expression. The expression of lipogenic transcription factors (SREBP-1c, PPARγ, LXRα) was increased, whereas that of a lipolytic nuclear factor PPARα was reduced in SH. SH was associated with reduced cytochrome P450 (Cyp)2e1 but increased Cyp4a. TNF type I receptor deficiency did not prevent obesity and SH.
In conclusion
, forced overfeeding with a high-fat diet in mice induces obesity, insulin resistance, and SH in the absence of TNF signaling or Cyp2e1 induction.

Supplementary material for this article can be found on the Hepatology website (

http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html

).

(Hepatology 2005;42:905–914.)
Efficacy and tolerability of quetiapine in patients with schizophrenia who switched from haloperidol, olanzapine or risperidone
Authors: Larmo Ilkka , Nayer André de , Windhager Elmar , Irmansyah  , Lindenbauer Bernhard , Rittmannsberger Hans , Platz Thomas , Jones A. Martin , Altman Charles
Published: September 2005

A post hoc analysis of the SPECTRUM trial was carried out to evaluate whether the improvements in efficacy and tolerability gained on switching to quetiapine occurred consistently for patients previously treated with either: haloperidol (n = 43); olanzapine (n = 66); or risperidone (n = 55) monotherapy. Patients were initiated with quetiapine to 400 mg/day over 7 days, and then flexibly dosed (300–750 mg/day) for 11 weeks. The mean (SD) modal dose of quetiapine was 501 (138) mg/day in the haloperidol subgroup, 472 (147) mg/day in the olanzapine subgroup and 485 (141) mg/day in the risperidone subgroup at the study endpoint. Switching to quetiapine induced significant improvements from baseline in PANSS scores, with least square mean changes in total scores of −32.5, −15.4, and −18.5 for patients previously treated with haloperidol, olanzapine and risperidone, respectively, (all p < 0.001 vs baseline). Significant improvements were also noted in CDSS scores, particularly for patients clinically depressed at baseline (all p < 0.001 vs baseline). There were significant reductions in EPS on the SAS and BAS for all subgroups (all p < 0.001 vs baseline). Switching to quetiapine produced efficacy and tolerability benefits regardless of whether their previous antipsychotic was haloperidol, olanzapine or risperidone. Copyright © 2005 John Wiley & Sons, Ltd.
Framework‐based design of a new all‐purpose molecular simulation application: The Adun simulator
Authors: Johnston Michael A. , Galván Ignacio Fdez. , Villà‐Freixa Jordi
Published: September 2005

Here we present Adun, a new molecular simulator that represents a paradigm shift in the way scientific programs are developed. The traditional algorithm centric methods of scientific programming can lead to major maintainability and productivity problems when developing large complex programs. These problems have long been recognized by computer scientists; however, the ideas and techniques developed to deal with them have not achieved widespread adoption in the scientific community. Adun is the result of the application of these ideas, including pervasive polymorphism, evolutionary frameworks, and refactoring, to the molecular simulation domain. The simulator itself is underpinned by the Adun Framework, which separates the structure of the program from any underlying algorithms, thus giving a completely reusable design. The aims are twofold. The first is to provide a platform for rapid development and implementation of different simulation types and algorithms. The second is to decrease the learning barrier for new developers by providing a rigorous and well‐defined structure. We present some examples on the use of Adun by performing simple free‐energy simulations for the adiabatic charging of a single ion, using both free‐energy perturbation and the Bennett's method. We also illustrate the power of the design by detailing the ease with which ASEP/MD, an elaborated mean field QM/MM method originally written in FORTRAN 90, was implemented into Adun. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1647–1659, 2005
Rotational superposition and least squares: The SVD and quaternions approaches yield identical results. Reply to the preceding comment by G. Kneller
Authors: Coutsias Evangelos A. , Seok Chaok , Dill Ken A.
Published: September 2005

We clarify once again that Kabsch's method and the Quaternion method are mathematically equivalent methods, that is, that they contain identical information and, when properly understood and applied, lead to identical answers to any questions regarding least‐squares rotational superposition, either by proper rotations or by rotation‐reflections. We also provide the correct bounds for the eigenvalue spectrum. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1663–1665, 2005
Lithium‐induced gene expression of inducible cyclic adenosine monophosphate early repressor in the rat adrenal gland
Authors: Spencer Corinne M. , Jahng Jeong Won , Ryu Vitaly , Houpt Thomas A.
Published: September 2005

Lithium has acute and chronic effects on the hypothalamic‐pituitary‐adrenal gland (HPA) axis that are important for both therapeutic (e.g., treatment of mood disorders) and experimental (e.g., as the toxin in conditioned taste aversion studies) applications. We visualized lithium‐induced activation of the HPA axis in rats by the adrenal expression of inducible cAMP early repressor (ICER), which is activated by elevated intracellular cAMP. We have shown that 1) intraperitoneal lithium chloride (LiCl) induces transient expression of ICER and c‐fos mRNAs in the rat adrenal cortex and increases plasma level of corticosterone; 2) the cortical expression of ICER mRNA by LiCl occurs in a dose‐dependent manner; 3) adrenal induction of ICER expression is delayed compared with c‐fos expression; 4) dexamethasone pretreatment (4 mg/kg) blocks corticosterone release and adrenocortical ICER induction either by systemic LiCl (76 mg/kg) or by restraint stress; and 5) intracerebroventricular LiCl (127 μg/5 μl) is sufficient for adrenocortical, but not medullary, ICER induction. These results suggest that adrenocortical ICER expression could serve as a reliable marker for lithium‐induced activation of the HPA axis. Understanding the activation of immediate‐early genes such as c‐fos or ICER in response to a single LiCl injection is an important first step in understanding the long‐term changes in gene expression elicited by lithium that are involved in its therapeutic and toxic effect. The pattern and mechanism by which lithium stimulates ICER transcription in the adrenal gland would serve as a useful model system in future studies of lithium. © 2005 Wiley‐Liss, Inc.
Subchronic haloperidol increases CB1 receptor binding and G protein coupling in discrete regions of the basal ganglia
Authors: Andersson Mikael , Terasmaa Anton , Fuxe Kjell , Strömberg Ingrid
Published: September 2005

The present study was designed to test whether chronic neuroleptic treatment, which is known to alter both expression and density of dopamine D2 receptors in striatal regions, has effects upon function and binding level of the cannabinoid CB1 receptor in the basal ganglia by using receptor autoradiography. As predicted, subchronic haloperidol treatment resulted in increased binding of 3H‐raclopride and quinpirole‐induced guanosine 5′‐O‐(γ‐[35S]thio)triphosphate ([35S]GTPγS) in the striatum when compared to that measured in control animals. This increased D2 receptor binding and function after 3 days washout was normalized after a 2‐week washout period. Effect of haloperidol treatment was studied for CB1 receptor binding and CP55,940‐stimulated [35S]GTPγS in the striatum, globus pallidus, and substantia nigra. 3[H]CP55,940 binding levels were found in rank order from highest to lowest in substantia nigra > globus pallidus > striatum. Furthermore, subchronic haloperidol treatment resulted in elevated binding levels of 3[H]CP55,940 in the striatum and the substantia nigra and CB1 receptor‐stimulated [35S]GTPγS bindings in the substantia nigra after 3 days washout. These increased binding levels were normalized at 1–4 weeks after termination of haloperidol treatment. Haloperidol treatment had no significant effect on CB1 receptor or [35S]GTPγS binding levels in globus pallidus. The results help to elucidate the underlying biochemical mechanism of CB1 receptor supersensitivity after haloperidol treatment. © 2005 Wiley‐Liss, Inc.
Disruption of endoplasmic reticulum calcium stores is involved in neuronal death induced by glycolysis inhibition in cultured hippocampal neurons
Authors: Hernández‐Fonseca Karla , Massieu Lourdes
Published: September 2005

Disturbances in neuronal calcium homeostasis have been implicated in a variety of neuropathological conditions, including cerebral ischemia, hypoglycemia, and epilepsy, and possibly constitute part of the cell death process associated with chronic neurodegenerative disorders. We investigated if endoplasmic reticulum (ER) calcium stores participate in neuronal death triggered by moderate glycolysis inhibition induced by iodoacetate, an inhibitor of glyceraldehyde‐3‐phosphate dehydrogenase, in cultured hippocampal neurons. Results show that exposure to iodoacetate leads to a slow partial decrease in cell survival, which is significantly prevented in the absence of Ca2+ or in the presence of the calcium chelator BAPTA‐AM. Treatment with caffeine and a low (1 μM) concentration of ryanodine, which activates the ryanodine receptor (RyR), exacerbates neuronal death, whereas dantrolene and 25 μM ryanodine, which antagonizes RyR, prevents damage. Xestospongin C (XeC), an antagonist of the inositol‐3‐phosphate (IP3) receptor (IP3R) also prevents neuronal damage. Inhibitors of the ER calcium ATPase (sarcoendoplasmic reticulum Ca2+ ATPase; SERCA) have no effect. The decrease in ATP levels induced by iodoacetate is potentiated by caffeine and prevented by dantrolene. Although only a slight increase in glutamate extracellular levels is observed 3.5 hr after iodoacetate exposure, the N‐methyl‐D‐aspartate (NMDA) glutamate receptor antagonist, MK‐801, efficiently prevents neuronal damage. Taken together, the data suggest that neuronal death induced during moderate glycolysis inhibition involves calcium influx through NMDA receptors and calcium release from intracellular ER stores. These results might be relevant to the understanding the mechanisms involved in neuronal damage related to aging and chronic neurodegenerative diseases, which have been associated with decreased glucose metabolism. © 2005 Wiley‐Liss, Inc.
Kainate‐induced zinc translocation from presynaptic terminals causes neuronal and astroglial cell death and mRNA loss of BDNF receptors in the hippocampal formation and amygdala
Authors: Revuelta Mati , Castaño Angélica , Machado Alberto , Cano Josefina , Venero José L.
Published: September 2005

To evaluate the potential role of endogenous zinc in the pathophysiology of epilepsy, we injected kainic acid into the medial septum, which evokes seizure activity and delayed hippocampal degeneration. Different approaches were used. In the hippocampus, we found a movement of zinc from the synaptic compartment to CA1 pyramidal neurons and astrocytes after kainate. The same was true in the amygdala. We found that in those areas showing intense zinc bleaching there was also a loss of reactive astrocytes, which supports the view that release of synaptic zinc induces astrocytic cell death. We have also tested whether the kainate‐induced zinc movement from the synaptic compartment to neuronal or glial cells alters the expression of brain‐derived neurotrophic factor (BDNF) and its high‐affinity receptor, trkB. There was a prominent loss of expression of trkB mRNA in areas that coincided precisely with those displaying astrocyte loss and zinc bleaching. In the amygdala, these events were accompanied by a high upregulation of BDNF mRNA. To demonstrate further a role of synaptic zinc in hippocampal pathology, we used two different approaches. We first injected different doses of zinc chloride in the CA1 area. At lower doses (0.1–10 nmol), zinc chloride selectively induced apoptosis in CA1 pyramidal neurons and dentate granular neurons. In a second approach, we found that hippocampal zinc chelation was effective in protecting CA1 pyramidal neurons against kainate‐induced cell death. © 2005 Wiley‐Liss, Inc.
Complex‐environment rearing prevents prenatal hypoxia‐induced deficitsin hippocampal cellular mechanisms necessary for memory consolidationin the adult Wistar rat
Authors: Foley Andrew G. , Murphy Keith J. , Regan Ciaran M.
Published: September 2005

Hypoxic episodes in utero can result in enduring and debilitating neurological sequelae that include nonprogressive motor disorders and/or significant learning deficits. The extent of long‐term disruption of synaptic function following prenatal hypoxia and its subsequent effect on learning ability, however, remain to be established. Polysialylation of the neural cell adhesion molecule, a cellular event integral to the consolidation of diverse learning paradigms, was used to correlate cellular end points with learning deficits as a consequence of prenatal hypoxia. Pregnant Wistar dams exposed to hypobaric hypoxia during gestational days 10–20 had significantly reduced litter sizes, but the lack of effect on subsequent pup weight gain suggested no gross developmental deficit. By contrast, adult animals with prior in utero hypoxia exhibited significant learning difficulties in both acquisition of a water maze spatial learning task and recall of a passive avoidance paradigm. Learning deficits correlated with a significant reduction in the frequency of polysialylated neurons in the dentate infragranular zone and a blunting of their transient activation 12 hr following task acquisition. Rearing animals with prior prenatal hypoxia in a complex environment, however, eliminated the task acquisition and recall deficits and restored dentate polysialylated cell frequency and their transient posttraining increase. © 2005 Wiley‐Liss, Inc.
Single‐fiber EMG with a concentric needle electrode: Validation in myasthenia gravis
Authors: Sarrigiannis Ptolemaios G. , Kennett Robin P. , Read Simon , Farrugia Maria E.
Published: September 2005

We performed a retrospective study to validate whether a disposable concentric needle electrode (CNE) can be used in place of a single‐fiber (SF) electrode for jitter measurements in myasthenia gravis (MG). Normal values for voluntary contraction of orbicularis oculi (OO) and extensor digitorum communis (EDC) were collected from 20 healthy subjects. The method was validated by a retrospective analysis of 56 consecutive MG patients, the “gold standard” being a positive acetylcholine receptor (AChR) antibody titer at the time of the electrophysiological (electromyography) study and the clinical diagnosis. Receiver operating characteristic (ROC) curves were constructed to define maximal sensitivity and specificity of the technique. The sensitivity was 96.4% (95% confidence interval 87.5%–99.6%), with no false‐positive results, similar to traditional SF EMG and confirming that the disposable CNE is a justifiable alternative. Muscle Nerve, 2005
Randomized controlled trial of modafinil for the treatment of fatigue in postpolio patients
Authors: Chan K. Ming , Strohschein Fay J. , Rydz David , Allidina Amyn , Shuaib Ashfaq , Westbury Chris F.
Published: September 2005

The purpose of this study was to test whether modafinil is effective in alleviating the symptoms of fatigue in postpolio patients, because it has been helpful for such symptoms in other neurologic disorders. Using a double‐blind, randomized, placebo‐controlled cross‐over design, 14 postpolio patients with moderate to severe fatigue were assigned to receive modafinil or placebo first. Piper Fatigue Scale, Epworth Sleepiness Scale, digit span, and reaction time tests were done at baseline and then at weekly intervals. The Piper Fatigue Scale scores improved by 27 ± 40% (mean ± SD) following modafinil and by 43 ± 36% following placebo. Scores for most of the other tests did not change during the study. Therefore, we conclude that modafinil was not effective in alleviating the symptoms of fatigue in postpolio patients. Muscle Nerve, 2005
Poly(p‐phenylenevinylene) presenting pendent pentaphenylene dendron groups for light‐emitting diodes
Authors: Tseng Ya‐Hsien , Wu Fang‐Iy , Shih Ping‐I , Shu Ching‐Fong
Published: September 2005

We have synthesized, using the Gilch method, a novel poly(p‐phenylenevinylene) derivative (PPV‐PP) containing two pendent pentaphenylene dendritic wedges, and have characterized its structure and properties. The incorporated side chain pentaphenylene dendrons serve as solubilizing groups, prevent π‐stacking interactions from occurring between the polymer main chains, and suppress the formation of excimers in the solid state. Photoluminescence studies indicate that efficient intramolecular energy transfer occurred from the photoexcited pentaphenylene groups to the poly(p‐phenylenevinylene) backbone. The polymer film exhibits a maximum emission at 510 nm and had a photoluminescence efficiency of 46%, which is similar to that measured in dilute solution. The photoluminescence spectra remained almost unchanged after thermal annealing at 150 °C for 20 h, and displayed inhibited excimer formation. Polymer light‐emitting diodes that we fabricated in the configuration ITO/PEDOT/PPV‐PP/Mg:Ag/Ag exhibited a maximum emission peak at 513 nm, corresponding to the green region [x = 0.30 and y = 0.62 in the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates]. The maximum brightness and maximum luminance efficiency were 1562 cd/m2 and 1.93 cd/A, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5147–5155, 2005
Synthesis and helical conformation of poly(N‐propargylamides) carrying L‐aspartic acid in the side chain
Authors: Zhao Haichao , Sanda Fumio , Masuda Toshio
Published: September 2005

Aspartic acid‐based novel poly(N‐propargylamides), i.e., poly[N‐(α‐tert‐butoxycarbonyl)‐L‐aspartic acid β‐benzyl ester N′‐propargylamide] [poly(1)] and poly[N‐(α‐tert‐butoxycarbonyl)‐L‐aspartic acid α‐benzyl ester N′‐propargylamide] [poly(2)] with moderate molecular weights were synthesized by the polymerization of the corresponding monomers 1 and 2 catalyzed with (nbd)Rh+[η6‐C6H5B−(C6H5)3] in CHCl3 at 30 °C for 2 h in high yields. The chiroptical studies revealed that poly(1) took a helical structure in DMF, while poly(2) did not in DMF but did in CH2Cl2, CHCl3, and toluene. The helicity of poly(1) and poly(2) could be tuned by temperature and solvents. Poly(2) underwent solvent‐driven switch of helical sense, accompanying the change of the tightness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5168–5176, 2005
Organosoluble star polymers from a cyclodextrin core
Authors: Karaky Khaled , Reynaud Stéphanie , Billon Laurent , François Jeanne , Chreim Yamama
Published: September 2005

Well‐defined star polymers were synthesized with a combination of the core‐first method and atom transfer radical polymerization. The control of the architecture of the macroinitiator based on β‐cyclodextrin bearing functional bromide groups was determined by 13C NMR, fast atom bombardment mass spectrometry, and elemental analysis. In a second step, the polymerization of the tert‐butyl acrylate monomer was optimized to avoid a star–star coupling reaction and allowed the synthesis of a well‐defined organosoluble polymer star. The determination of the macromolecular dimensions of these new star polymers by size exclusion chromatography/light scattering was in agreement with the structure of armed star polymers in a large range of predicted molecular weights. This article describes a new approach to polyelectrolyte star polymers by postmodification of poly(tert‐butyl acrylate) by acrylic arm hydrolysis in a water‐soluble system. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5186–5194, 2005
Experimental and theoretical analysis of electropolymerized PMeT thin films
Authors: Velumani S. , Ascencio J. A. , Canizal G. , Sebastián P. J. , García‐Serrano J. , Pal U.
Published: September 2005

It is reported that the physical analysis of poly(3‐methylthophene) (PMeT) thin films were doped with BF anions, which were deposited on tin oxide‐coated glass and stainless steel substrates using electropolymerization technique. The atomistic and electronic structures were evaluated to understand the main principles for the pure and doped PMeT polymers that give the photonic and conductivity properties for this kind of materials. It is found that galvanostatic method is more suitable for the electropolymerization of PMeT on conducting glass or flexible metal surfaces. The films were characterized using SEM, AFM, XRD, FTIR, Raman, and UV–vis absorption techniques. Raman and FTIR spectra of the samples revealed no signal related to the Li or the anion BF dopant, indicating that the optimum dopant concentration was well below the threshold value. Apart from the dopant influence, which is a well understood phenomenon, an attempt has been made to explain the influence of the lithium in the polymer matrix. The Li+ ions incorporated into the PMeT films form highly confined conjugational defects, neither dynamically nor electronically coupled with the host lattice. Using density function theory calculations, we could determine the optimum geometrical configurations of the cis and trans polymers and their corresponding electronic structure modification because of the presence of Li+ atoms controlling the electronic band gaps. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3058–3068, 2005
Orthogonal array design in optimizing the extraction efficiency of active constituents from roots of Panax notoginseng
Authors: Dong T. T. X. , Zhao K. J. , Huang W. Z. , Leung K. W. , Tsim K. W. K.
Published: September 2005

The root of Panax notoginseng (Radix Notoginseng, Sanqi) is a commonly used traditional Chinese medicine, which is mainly cultivated in Wenshan of Yunnan China. The identified active constituents in Radix Notoginseng include saponin, ßavonoid and polysaccharide; however, the levels of these active constituents vary greatly with different extraction processes. This variation causes a serious problem in standardizing the herbal extract. By using HPLC and spectrophotometry, the contents of notoginsenoside R1, ginsenoside Rg1, Rb1, Rd, and ßavonoids were determined in the extracts of Radix Notoginseng that were derived from different processes of extraction according to an orthogonal array experimental design having three variable parameters: nature of extraction solvent, extraction volume and extraction time. The nature of extraction solvent and extraction volume were two distinct factors in obtaining those active constituents, while the time of extraction was a subordinate factor. The optimized condition of extraction therefore is considered to be 20 volumes of water and extracted for 24 h. In good agreement with the amount of active constituents, the activity of anti‐platelet aggregation was found to be the highest in the extract that contained a better yield of the active constituents. The current results provide an optimized extraction method for the quality control of Radix Notoginseng. Copyright © 2005 John Wiley & Sons, Ltd.
Is combining meta‐GGA correlation functionals with the OPTX exchange functional useful?
Authors: Proynov Emil I. , Thakkar Ajit J.
Published: September 2005

The recent generalized gradient approximation (GGA) density functional OCS1 of Handy and Cohen is implemented in the deMon code and tested on a carefully selected set of problems. OCS1 is found to be accurate for molecular atomization energies, transition metal–ligand bonds, and systems with intramolecular hydrogen bonds. However, OCS1 encounters problems for systems with intermolecular hydrogen bonds. It also tends to elongate bond lengths systematically, and sometimes significantly. The OPTX exchange is combined with three meta‐GGA correlation functionals, Lap3, τ1, and τ2, the latter reported for the first time. The new meta‐GGA scheme OPTX exchange plus τ2 correlation called Oτ2 yields improved molecular geometries, NMR shielding constants, and an improved barrier height for the H+H2 reaction. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Screening for proteolytic activities in snake venom by means of a multiplexing electrospray ionization mass spectrometry assay scheme
Authors: Liesener André , Perchuc Anna‐Maria , Schöni Reto , Wilmer Marianne , Karst Uwe
Published: September 2005

A multiplexed mass spectrometry based assay scheme for the simultaneous determination of five different substrate/product pairs was developed as a tool for screening of proteolytic activities in snake venom fractions from Bothrops moojeni. The assay scheme was employed in the functional characterization of eight model proteases. Time‐resolved reaction profiles were generated and the relative reaction progress at each time point was determined. These were used to semi‐quantitatively sort the catalytic activities of each enzyme towards the respective substrates into six classes. The resulting activity pattern served as an activity fingerprint for each enzyme. The multiplex assay scheme was then applied to a screening for proteolytic activities in fractions of the pre‐separated venom from B. moojeni. Activity patterns of each fraction were generated and used to sort the fractions into three different categories of activity. By comparison of the fingerprint activity patterns of the venom fractions and the model enzymes, a compound with proteolytic properties similar to activated protein C was detected. Copyright © 2005 John Wiley & Sons, Ltd.
Effects of econazole, fungizone and pimafucin on cell growth, lysosomal enzyme activity and sulphate metabolism of cultured human skin fibroblasts and amniotic fluid cells
Authors: Butterworth J.
Published: September 2005

Human skin fibroblasts and amniotic fluid cells showed sensitivity to antifungal agents in the order Econazole < Pimafucin < Fungizone, with the last initially reducing cell growth 10‐20%, even at the level recommended for cell culture. The activities of the lysosomal enzymes α‐l‐fucosidase, β‐d‐glucuronidase and α‐d‐mannosidase were unaffected, even by high concentrations of all three antifungal agents. Sulphate incorporation by cultured fibroblasts was increased by removal of sulphate salts and Crystamycin (contains streptomycin sulphate) from the culture medium. Sulphate incorporation into and degradation from macromolecules was only slightly reduced by antifungal agents. Human skin fibroblasts and amniotic fluid cells can be cultured long term in the presence of Econazole or Fungizone and used for lysosomal enzyme assay and sulphate kinetic studies.
Presymptomatic diagnosis: Metachromatic eukodystrophy or pseudo arylsulphatase a deficiency?
Authors: Kihara H. , Fluharty A. L. , Ng W. G. , Leider W.
Published: September 2005

Diagnosis of metachromatic leukodystrophy (MLD) was established in the proband at age 27 months. An examination of the family arylsulphatase A profile revealed that the father and younger sibling, age 2 months, had very low enzyme activities like the proband. The father, in all likelihood, had the pseudo arylsulphatase A deficiency trait, but the sibling could be either pseudodeficient or affected with MLD. The fibroblast cerebroside sulphate loading test confirmed that the father had pseudo arylsulphatase A deficiency. The test also indicated that the sibling was affected with MLD. This was confirmed by clinical evidence of neurological degeneration by 18 months.
Video gaming promotes concussion knowledge acquisition in youth hockey players
Authors: Goodman David , Bradley Nori L. , Paras Bradley , Williamson Ian J. , Bizzochi James
Published: September 2005

While the positive uses for video games in an educational setting have also been established, the educational aim is usually made explicit. The goal of this research was to develop a video game wherein the educational aspect was implicitly embedded in the video game, such that the gameing activity remained interesting and relevant. Following a pilot study to confirm the usability of an in‐house developed game, two studies were conducted with 11–17 year old hockey players (, ). Results demonstrated that participants playing the experimental version of the video game scored significantly higher on a concussion symptoms questionnaire, in a significantly faster time, than participants playing the control version of the game. Most participants indicated that they enjoyed the game and would play it again. These results suggest that educational material can be conveyed successfully and in an appealing manner via video game play.
Non‐resident fathers’ relationships with their secondary school age children: Determinants and children's mental health outcomes
Authors: Flouri Eirini
Published: September 2005

Data from 520 British secondary school age children were used to explore determinants of and mental health outcomes (measured with the Strengths and Difficulties Questionnaire) from their non‐resident fathers’ relationships (child‐reported father's involvement and frequency of contact) with them. Frequency of contact was negatively related to time elapsed since parents separated, and was higher if fathers were single than partnered. Compared to White, non‐White adolescents reported lower frequency of father's contact but not lower father's involvement. Father's involvement was related positively to mother's involvement and negatively to interparental conflict. As a whole, non‐resident father's involvement and frequency of contact did not improve the regression models predicting children's total difficulties or pro‐social behaviour. Even after controlling for other factors non‐resident father's involvement did not predict child's difficulties or pro‐social behaviour, although frequency of contact was negatively associated with child's emotional symptoms. Neither child's ethnicity or gender nor mother's partner status moderated the link between child's mental health outcomes and non‐resident father's involvement or frequency of contact.
Mental illness stigma: Concepts, consequences, and initiatives to reduce stigma
Authors: Rüsch Nicolas , Angermeyer Matthias C. , Corrigan Patrick W.
Published: September 2005

Persons with mental illness frequently encounter public stigma and may suffer from self-stigma. This review aims to clarify the concept of mental illness stigma and discuss consequences for individuals with mental illness. After a conceptual overview of stigma we discuss two leading concepts of mental illness stigma and consequences of stigma, focussing on self-stigma/empowerment and fear of stigma as a barrier to using health services. Finally, we discuss three main strategies to reduce stigma - protest, education, and contact – and give examples of current anti-stigma campaigns. Well-designed anti-stigma initiatives will help to diminish negative consequences of mental illness stigma.
Endothelial progenitor cell sprouting in spheroid cultures is resistant to inhibition by osteoblasts: A model for bone replacement grafts
Authors: Stahl Andreas , Wu Xiao , Wenger Andreas , Klagsbrun Michael , Kurschat Peter
Published: September 2005

Survival of tissue transplants generated in vitro is strongly limited by the slow process of graft vascularization in vivo. A method to enhance graft vascularization is to establish a primitive vascular plexus within the graft prior to transplantation. Endothelial cells (EC) cultured as multicellular spheroids within a collagen matrix form sprouts resembling angiogenesis in vitro. However, osteoblasts integrated into the graft suppress EC sprouting. This inhibition depends on direct cell–cell‐interactions and is characteristic of mature ECs isolated from preexisting vessels. In contrast, sprouting of human blood endothelial progenitor cells is not inhibited by osteoblasts, making these cells suitable for tissue engineering of pre‐vascularized bone grafts.
Antegrade regional cerebral perfusion
Authors: Tchervenkov Christo I. , Al-Khaldi Abdulaziz , Shum-Tim Dominique
Published: September 2005

A quiet and bloodless field providing optimal surgical conditions has been a crucial prerequisite for the performance of complex cardiac repairs in early life. The use of deep hypothermic circulatory arrest has fulfilled this role, and has been a catalyst for the development of neonatal and infant cardiac surgery. The recently increased awareness of possibly increased incidence of adverse neurological events and developmental outcome associated with this technique,1–5however, has led to a general trend away from its use. In its place, techniques have been developed to provide cerebral perfusion during reconstruction of the aortic arch and the Norwood operation. Some have described the techniques as regional low-flow perfusion. In our opinion, they are described more accurately as antegrade regional cerebral perfusion. In this review, we discuss the recently described techniques for such antegrade regional cerebral perfusion during surgery on the aortic arch, with emphasis both on the Norwood operation and the observed physiological changes in the cerebral and systemic circulations. The neurologic and developmental outcomes following the use of the technique are still unknown.
Inherent correlation between decreased marine sedimentary phosphorus and glacial atmospheric CO2 decline
Authors: Weng Huan‐Xin , Qin Ya‐Chao , Weng Jing‐Ke
Published: September 2005

The environmental and biogeochemical information implicated by a sediment column from the northern shelf of the South China Sea suggests that the vertical phosphorus variation in the sediment column bares a negative correlation with those of calcium carbonate and cadmium. The functional correlation between CO2 and PO43− in seawater is given by calculating a series of chemical equilibriums, indicating a coupling relationship between the accumulation of marine sedimentary P and the atmospheric CO2 change. The decreased P accumulation in marine sediments correlated to the increase of marine primary production during the glacial period might act as a key factor causing glacial atmospheric CO2 decline.
Computational study of the reaction of N(D2) atoms with CH2F radicals: An example of a barrier-free reaction involving very high internal energies
Authors: Cimas Alvaro , Rayón Víctor M. , Aschi Massimiliano , Barrientos Carmen , Sordo José A. , Largo Antonio
Published: September 2005

The singlet potential-energy surface for the N(D2)+CH2F(A′2) reaction has been studied employing both second-order Møller-Plesset and density-functional theories. The energies of the involved species have been refined using the Gaussian-2, complete basis set, and coupled-cluster singles and doubles (triples) methods. The reaction proceeds through the formation of an initial intermediate, which does not involve any activation barrier. Based on the energy profile for the singlet potential-energy surface, the preferred product should be the most exothermic one, namely, HCN+HF, followed by HNC+HF and FCN+H2. This result seems in contradiction with a computational study of the kinetics of the title reaction in terms of the statistical theories, which leads to the prediction that the production of HNC+HF should be the dominant channel. Consequently, a limited molecular-dynamics study has been carried out, concluding that in fact the system behaves in a nonstatistical way. According to the molecular-dynamics study, the most exothermic channel, HCN+HF, should be the dominant one. An analysis of the possible role of the singlet surface in the reaction of N(S4) with CH2F(A′2) has also been carried out. The computational study shows that the microcanonical coefficients for the nonadiabatic channels are much smaller than the competing adiabatic ones. Therefore, the reaction of N(S4) with CH2F(A′2) should proceed on the triplet surface without spin change.
Photoionization mass spectrometer for studies of flame chemistry with a synchrotron light source
Authors: Cool Terrill A. , McIlroy Andrew , Qi Fei , Westmoreland Phillip R. , Poisson Lionel , Peterka Darcy S. , Ahmed Musahid
Published: September 2005

A flame-sampling molecular-beam photoionization mass spectrometer, recently designed and constructed for use with a synchrotron-radiation light source, provides significant improvements over previous molecular-beam mass spectrometers that have employed either electron-impact ionization or vacuum ultraviolet laser photoionization. These include superior signal-to-noise ratio, soft ionization, and photon energies easily and precisely tunable [E∕ΔE(FWHM)≈250–400] over the 7.8–17-eV range required for quantitative measurements of the concentrations and isomeric compositions of flame species. Mass resolution of the time-of-flight mass spectrometer is m∕Δm=400 and sensitivity reaches ppm levels. The design of the instrument and its advantages for studies of flame chemistry are discussed.
Theoretical studies of UO2(H2O)n2+,NpO2(H2O)n+, and PuO2(H2O)n2+ complexes (n=4–6) in aqueous solution and gas phase
Authors: Cao Zhiji , Balasubramanian K.
Published: September 2005

Extensive ab initio calculations both in gas phase and solution have been carried out to study the equilibrium structure, vibrational frequencies, and bonding characteristics of various actinyl (UO22+,NpO2+, and PuO22+) and their hydrated forms, AnO2(H2O)nz+ (n=4, 5, and 6). Bulk solvent effects were studied using a continuum method. The geometries were fully optimized at the coupled-cluster singles + doubles (CCSD), density-functional theory (DFT), and Møller-Plesset (MP2) level of theories. In addition vibrational frequencies have been obtained at the CCSD as well as MP2/DFT levels. The results show that both the short-range and long-range solvent effects are important. The combined discrete-continuum model, in which the ionic solute and the solvent molecules in the first and second solvation shells are treated quantum mechanically while the solvent is simulated by a continuum model, can predict accurately the bonding characteristics. Moreover, our values of solvation free energies suggest that five- and six-coordinations are equally preferred for UO22+, and five-coordinated species are preferred for NpO2+ and PuO22+. On the basis of combined quantum-chemical and continuum treatments of the hydrated complexes, we are able to determine the optimal cavity radii for the solvation models. The coupled-cluster computations with large basis sets were employed for the vibrational spectra and equilibrium geometries both of which compare quite favorably with experiment. Our most accurate computations reveal that both five- and six-coordination complexes are important for these species.
Infrared spectra of seeded hydrogen clusters: (para-H2)N–N2O and (ortho-H2)N–N2O, N=2–13
Authors: Tang Jian , McKellar A. R. W.
Published: September 2005

High-resolution infrared spectra of clusters containing para-H2 and/or ortho-H2 and a single nitrous oxide molecule are studied in the 2225-cm−1 region of the ν1 fundamental band of N2O. The clusters are formed in pulsed supersonic jet expansions from a cooled nozzle and probed using a tunable infrared diode laser spectrometer. The simple symmetric rotor-type spectra generally show no resolved K structure, with prominent Q-branch features for ortho-H2 but not para-H2 clusters. The observed vibrational shifts and rotational constants are reported. There is no obvious indication of superfluid effects for para-H2 clusters up to N=13. Sharp transitions due to even larger clusters are observed, but no definite assignments are possible. Mixed (para-H2)N–(ortho-H2)M–N2O cluster line positions can be well predicted by linear interpolation between the corresponding transitions of the pure clusters.
Fast localized orthonormal virtual orbitals which depend smoothly on nuclear coordinates
Authors: Subotnik Joseph E. , Dutoi Anthony D. , Head-Gordon Martin
Published: September 2005

We present here an algorithm for computing stable, well-defined localized orthonormal virtual orbitals which depend smoothly on nuclear coordinates. The algorithm is very fast, limited only by diagonalization of two matrices with dimension the size of the number of virtual orbitals. Furthermore, we require no more than quadratic (in the number of electrons) storage. The basic premise behind our algorithm is that one can decompose any given atomic-orbital (AO) vector space as a minimal basis space (which includes the occupied and valence virtual spaces) and a hard-virtual (HV) space (which includes everything else). The valence virtual space localizes easily with standard methods, while the hard-virtual space is constructed to be atom centered and automatically local. The orbitals presented here may be computed almost as quickly as projecting the AO basis onto the virtual space and are almost as local (according to orbital variance), while our orbitals are orthonormal (rather than redundant and nonorthogonal). We expect this algorithm to find use in local-correlation methods.
Suppression of turbulence at low power input in a model for plasma confinement transitions
Authors: Ball R.
Published: September 2005

A physics-based condition is used to unfold a trapped or persistent degenerate singularity in a dynamical model for plasma confinement transitions. The bifurcation structure of the resulting enhanced model indicates that shear flow can actually grow as the power input is withdrawn, with concomitant supersuppression of turbulence. This is an important and testable prediction that suggests new design, management, and optimization strategies for new-generation fusion experiments.
Effective permittivity of planar composites with randomly or periodically distributed conducting fibers
Authors: Liu L. , Matitsine S. M. , Gan Y. B. , Rozanov K. N.
Published: September 2005

Theoretical and experimental studies have been conducted on the effective electromagnetic properties of planar composites at microwave frequencies, with embedded conductive fibers of various volume concentrations. Two types of distribution are considered: random and periodic. Experimental results for the transmission coefficient and effective permittivity are obtained via the free space method. Simulation results are obtained using the finite element method (FEM). Good agreement is found between the measured and computed results, indicating the suitability of the FEM as a theoretical modeling tool for such composites, as compared to other numerical methods, such as the method of moments. It is also found that the type of distribution affects the effective permittivity of the composites: lower microwave permittivity with broader peak response is observed for composites with randomly distributed fibers, in comparison to that with periodically distributed fibers.
Thermal conductivity of nanotubes revisited: Effects of chirality, isotope impurity, tube length, and temperature
Authors: Zhang Gang , Li Baowen
Published: September 2005

We study the dependence of the thermal conductivity of single-walled nanotubes on chirality, isotope impurity, tube length, and temperature by nonequilibrium molecular-dynamics method with accurate potentials. It is found that, contrary to electronic conductivity, the thermal conductivity is insensitive to the chirality. The isotope impurity, however, can reduce the thermal conductivity up to 60% and change the temperature dependence behavior. We also found that the tube length dependence of thermal conductivity is different for nanotubes of different radii at different temperatures.
Kinetics of nonionic surfactant adsorption at a fluid-fluid interface from a micellar solution
Authors: Mohrbach Hervé
Published: September 2005

The kinetics of nonionic surfactant adsorption at a fluid-fluid interface from a micellar solution is considered theoretically. Our model takes into account the effect of micelle relaxation on the diffusion of the free surfactant molecules. It is shown that nonionic surfactants undergo either a diffusion or a kinetically limited adsorption according to the characteristic relaxation time of the micelles. This gives a new interpretation for the observed dynamical surface tension of micellar solutions.
Molecular photoionization cross sections in electron propagator theory: Angular distributions beyond the dipole approximation
Authors: Seabra G. M. , Kaplan I. G. , Ortiz J. V.
Published: September 2005

Corrections to dipole approximation results for angular distributions in photoionization of first-row hydrides have determined by using Dyson orbitals calculated with ab initio electron propagator theory and by considering the full multipole expansion for the incident photon representation. The relative importance of first-order corrections which consist of electric quadrupole and magnetic dipole terms and of higher-order terms has been estimated as a function of photon energy. Multipole corrections to the dipole approximation depend on photon energy and on the characteristics of the Dyson orbitals.