bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenomenological similarities between protein denaturation and small‐molecule dissolution: Insights into the mechanism driving the thermal resistance of globular proteins
Authors: Ragone Raffaele 
Published: December 2003

AbstractThis article shows that the stability profiles of thermophilic proteins are significantly displaced toward higher temperatures as compared to those of mesophilic proteins. A similar trend characterizes the aqueous transfer of N‐alkyl amides. In fact, as a general feature of transfer processes, liquid dissolution profiles are centered at temperatures higher than those of solid ones. This behavior is governed by packing contributions. A partition of the unfolding thermodynamics based on the analysis of phenomenological temperatures common to dissolution and unfolding phenomena provides a clue to understanding the mechanism of thermal stabilization. In fact, the position of stability profiles along the temperature axis does not appear to depend on solvation of internal residues. Instead, it is notably affected by solidlike components, whose progressive decrease appears to drive the heat denaturation temperature increase of most thermostable proteins. As a corollary, it is shown that there are actually two limiting mechanisms of thermal stabilization. Proteins 2004. © 2003 Wiley‐Liss, Inc.
Novel protein and Mg2+ configurations in the Mg2+GDP complex of the SRP GTPase ffh
Authors: Focia Pamela J. , Alam Hena , Lu Thanh , Ramirez Ursula D. , Freymann Douglas M. 
Published: December 2003

AbstractFfh is the signal sequence recognition and targeting subunit of the prokaryotic signal recognition particle (SRP). Previous structural studies of the NG GTPase domain of Ffh demonstrated magnesium‐dependent and magnesium‐independent binding conformations for GDP and GMPPNP that are believed to reflect novel mechanisms for exchange and activation in this member of the GTPase superfamily. The current study of the NG GTPase bound to Mg2+GDP reveals two new binding conformations—in the first the magnesium interactions are similar to those seen previously, however, the protein undergoes a conformational change that brings a conserved aspartate into its second coordination sphere. In the second, the protein conformation is similar to that seen previously, but the magnesium coordination sphere is disrupted so that only five oxygen ligands are present. The loss of the coordinating water molecule, at the position that would be occupied by the oxygen of the γ‐phosphate of GTP, is consistent with that position being privileged for exchange during phosphate release. The available structures of the GDP‐bound protein provide a series of structural snapshots that illuminate steps along the pathway of GDP release following GTP hydrolysis. Proteins 2004;54:000–000. © 2003 Wiley‐Liss, Inc.
Semiempirical QM/MM method for studying HCl adsorption on ice
Authors: Bolton Kim 
Published: December 2003

AbstractThe combined QM/MM method, where the QM forces are obtained from a fitted PM3 semiempirical Hamiltonian, is used to study HCl adsorption at an ice surface ledge defect site. The PM3‐SSP (PM3 with system‐specific parameters) Hamiltonian allows for multidimensional molecular dynamics simulations that are computationally inexpensive while still providing valid reaction dynamics. The simulations reveal that, depending on the initial position of the HCl above the ledge and the number and positions of dangling surface hydrogens, adsorption may be molecular or dissociative. HCl binding energies and geometries at the ice defect site are similar to those for adsorption at crystalline hexagon sites. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Ab initio description of the structure and dynamics of the nitrosomethane molecule in the first excited singlet and triplet electronic states
Authors: Dolgov Eugeniy K. , Bataev Vadim A. , Pupyshev Vladimir I. , Godunov Igor A. 
Published: December 2003

AbstractElectronic structure of the low‐lying excited states of the CH3NO molecule is considered. The detailed analysis of the first excited triplet and singlet states of this molecule is performed by different ab initio methods to estimate equilibrium geometry, barriers to internal rotation, harmonic frequencies, and adiabatic transition energies. Anharmonic vibrational approximations are also considered. The multidimensional VibSCF scheme and the 1‐D variational method for the section of the potential energy surface along the torsion coordinate are used. Theoretical results are found to be in good agreement with experimental data. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Possibility of a pressure‐induced 2N2 → N4 reaction
Authors: Evangelisti Stefano 
Published: December 2003

AbstractThe CAS‐SCF energy of an N4 cluster for a fixed value of the system volume (constrained to a D2d symmetry) is studied. It is shown that, for a wide range of volumes, two minima exist: one corresponding to two separated N2 molecules and one to an N4 cluster with tetrahedric shape. For small values of the volume, the energy of the tetrahedric form becomes lower than the energy of the two N2 molecules. This suggests the possibility that, at high densities, tetrahedric N4 might be more stable than two N2 molecules, with a pressure‐drive phase transition between the two forms occurring at a very high pressure. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Extrapolation methods and scaled perturbation theory for determining intermolecular potential energy surfaces
Authors: Hodges Matthew P. , Bichoutskaia Elena , Tulegenov Akyl S. , Wheatley Richard J. 
Published: December 2003

AbstractWe construct potential energy curves for six rare‐gas dimers and several 1‐D cuts through two H2 … rare‐gas potential energy surfaces using two methods. The first is based on supermolecule dimer calculations at a low level of theory, extrapolated using monomer calculations at higher levels of theory. The second is based on perturbation theory calculations, where the effects of intramolecular electron correlation on different interaction terms are treated using approximate scaling relationships. Both methods are competitive with supermolecule dimer calculations at higher levels of theory and provide computationally efficient means of studying weakly bound systems. The methods are therefore suitable for calculations on larger systems for which accurate supermolecule methods would be computationally expensive. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Quantum vs. semiclassic initial value representation probabilities for nonreactive systems
Authors: Lago N. Faginas , Laganà A. , Riganelli A. 
Published: December 2003

AbstractThe initial value representation (IVR) of the semiclassic (SC) formulation of the probability of inelastic transitions have been investigated for collinear atom–diatom systems. An analysis of the convergence and accuracy of the calculated probabilities is performed by comparing SC‐IVR values calculated using an increasing number of trajectories with exact quantum results. Both far and near the threshold behaviors are considered. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Validating the PSL/Sugar Semantics Using Automated Reasoning
Authors: Gordon Michael J. C. 
Published: December 2003

Abstract.
The Accellera organisation selected Sugar, IBM’s formal specification language, as the basis for a standard to ‘drive assertion-based verification’ in the electronics industry. Sugar combines regular expressions, Linear Temporal Logic (LTL) and Computation Tree Logic (CTL) into a property language intended for both static verification (e.g. model checking) and dynamic verification (e.g. simulation). In 2003 Accellera decided to rename the evolving standard to ‘Accellera Property Specification Language’ (or ‘PSL’ for short). We motivate and describe a deep semantic embedding of PSL in the version of higher-order logic supported by the HOL 4 theorem-proving system. The main goal of this paper is to demonstrate that mechanised theorem proving can be a useful aid to the validation of the semantics of an industrial design language.
Actors and their Composition
Authors: Janneck Jörn W. 
Published: December 2003

Abstract.Modern environments for modelling and designing concurrent computational systems increasingly supportheterogeneoussystem models, which are characterised by different coordination mechanisms governing the interaction between concurrent components in different parts or at different levels of the model. These interaction semantics, also calledmodels of computation, pose a major challenge to the definition of the meaning of heterogeneous models, especially if such a definition is to be independent of any specific set of models of computation, ways of describing actors, or notations for describing models. This paper makes three main contributions. (1) It presents a framework for describing the semantics of actors and models of computation. Its central notion is the concept of a model of computation as a program transformation that composes actor descriptions into a description of a composite actor. This framework is entirely independent of any specific syntax for describing actors, or any particular modelling language. (2) It uses this framework to describe properties of actor compositions and models of computation, and to classify and analyse them. (3) Finally, it discusses the implications of this theory for the design of languages for describing actors and models of computation.
Homocystinuria due to cystathionine β‐synthase deficiency: Novel biochemical findings and treatment efficacy
Authors: Orendáč M. , Zeman J. , Stabler S. P. , Allen R. H. , Kraus J. P. , Bodamer O. , Stöckler‐Ipsiroglu S. , Kvasnička J. , Kožich V. 
Published: December 2003

AbstractSummary: To explore the pathogenesis of cystathionine β‐synthase (CBS) deficiency and to test the efficacy of pharmacological therapy we examined a panel of metabolites in nine homocystinuric patients under treated and/or untreated conditions. Off pharmacological treatment, the biochemical phenotype was characterized by accumulation of plasma total homocysteine (median 135 µmol/L) and blood S‐adenosylhomocysteine (median 246 nmol/L), and by normal levels of guanidinoacetate and creatine. In addition, enhanced remethylation was demonstrated by low serine level (median 81 µmol/L), and by increased concentration of methionine (median 76 µmol/L) and N‐methylglycine (median 6.8 µmol/L). Despite the substantially blocked transsulphuration, which was evidenced by undetectable cystathionine and severely decreased total cysteine levels (median 102 µmol/L), blood glutathione was surprisingly not depleted (median 1155 µmol/L). In 5 patients in whom pharmacological treatment was withdrawn, the differences of median plasma total homocysteine levels (125 µmol/L after withdrawal versus 33 µmol/L under treatment conditions), total cysteine levels (139 versus 211 µmol/L) and plasma serine levels (53 versus 103 µmol/L) on and off treatment demonstrated the efficacy of long‐term pyridoxine/betaine administration (p<0.05). The treatment also decreased blood S‐adenosylhomocysteine level (133 versus 59 nmol/L) with a borderline significance. In summary, our study shows that conventional treatment of CBS deficiency by diet and pyridoxine/betaine normalizes many but not all metabolic abnormalities associated with CBS deficiency. We propose that the finding of low plasma serine concentration in untreated CBS‐deficient patients merits further exploration since supplementation with serine might be a novel and safe component of treatment of homocystinuria.
Molecular genetic analysis of glycogen storage disease type Ia in 26 Chinese patients
Authors: Qiu W. J. , Gu X. F. , Ye J. , Han L.Sh. , Zhang Y. F. , Liu X. Q. 
Published: December 2003

AbstractSummary: Sequence analysis of 26 patients from Mainland China with glycogen storage disease type Ia revealed a high frequency of two mutations in the glucose‐6‐phosphatase gene. These mutations, 727G>T and R83H, were also found to be in linkage disequilibrium with a polymorphism at position 1176. These findings have implications for carrier detection and prenatal diagnosis of this disease in the Chinese population.
Clinical heterogeneity in patients with mutations in the NDUFS4 gene of mitochondrial complex I
Authors: Budde S. M. S. , van den Heuvel L. P. W. J. , Smeets R. J. P. , Skladal D. , Mayr J. A. , Boelen C. , Petruzzella V. , Papa S. , Smeitink J. A. M. 
Published: December 2003

AbstractSummary: A comparison of the clinical presentation, disease course and results of laboratory and imaging studies of all patients so far published with a NDUFS4 mutation are presented. This reveals marked clinical heterogeneity, even in patients with the same genotype.
The enhanced spontaneous activity of the diabetic colon is not the consequence of impaired inhibitory control mechanisms
Authors: Forrest A. , Parsons M. 
Published: December 2003

Summary1 Approximately 45% of patients with diabetes mellitus have gastrointestinal complications such as diarrhoea and constipation, but the underlying aetiology is unclear. The present study investigates alterations in spontaneous motility of the colon that may be, in part, responsible for these symptoms using an established animal model of diabetes.2 Rats were rendered diabetic by a single intraperitoneal injection of streptozotocin and age‐matched controls were injected with citrate buffer. Rats were sacrificed after 8‐weeks and proximal colonic circular muscle tissue mounted in organ baths.3 Spontaneous activity was observed in both control and diabetic tissues, but this activity was almost doubled in colonic tissue taken from diabetic rats. It was hypothesized that this increase was due to a deficit in inhibitory control of the colon in the diabetic state.4 Possible alterations in nitrergic and vasoactive intestinal polypeptide (VIP)ergic control were investigated using a range of pharmacological tools.5 Sodium nitroprusside, VIP and antioxidants (reduced glutathione, ascorbate and α‐tocopherol) inhibited the spontaneous activity, but the level of inhibition observed was not different in diabetic tissue compared with control.6 Arginine, [d‐p‐Cl‐Phe6, Leu17]‐VIP and α‐chymotrypsin had no effect on spontaneous activity in either sets of tissue.7 N‐nitro‐l‐arginine produced a small, but significant, increase in the level of spontaneous activity, but the degree of increase was not different between control and diabetic tissues.8 Western blots demonstrated that there was no inducible‐nitric oxide synthase (iNOS) in control or diabetic tissues and that the levels of endothelial‐NOS (eNOS) and neuronal‐NOS (nNOS) detected were not statistically significantly different. The [3H]‐citrulline assay established that the functionality of the NOS isoforms present were unaltered in the diabetic state.9 This study demonstrates that there is a marked alteration in motility in the colon taken from diabetic animals. However, the change in motility is unlikely to be due to a change in inhibitory control mechanisms and may be due to an increased excitability.
Adenosine affects the calcium dynamics of rat portal vein
Authors: Telang R. S. , Tripathi H. C. , Mishra S. K. , Raviprakash V. 
Published: December 2003

Summary1 The present study was carried out to characterize the effect of adenosine on calcium dynamics in the rat portal vein. Isolated portal vein of male albino rats was used as the experimental model as it exhibits autorhythmicity. Adenosine and its analogues 2‐CAD, N6‐CHA and NECA were used to characterize the type of adenosine receptor involved and 2‐CAD was used along with adenosine throughout the other part of study to characterize the effect of adenosine on Ca2+ dynamics.2 Adenosine and its analogues were found to inhibit the spontaneous contractions of rat portal vein in a concentration‐related manner. The order of potency was NECA > 2‐CAD > N6‐CHA > adenosine. Incubation of the tissue with CGS∼15943A, an adenosine receptor antagonist, had a per se enhancing effect on autorhythmicity. Adenosine and 2‐CAD failed to reverse the contractile response produced by hypertonic KCl (80 or 30 mm). Whereas adenosine and 2‐CAD effectively relaxed the tissues contracted with phenylephrine (10−5 m).3 Preincubation of the tissue with 2‐CAD (10−4, 10−5 or 10−6 m) for 5 min raised the threshold concentration of CaCl2 to evoke contractile response and also significantly increased the mean EC50 values of CaCl2. Nifedipine was found to be more potent than 2‐CAD on Ca2+ channels.4 The results of the present study suggest that the endogenous adenosine plays a significant role in producing vascular relaxation through the participation of A2 receptor subtype. This effect may be due to its inhibitory effect on release of Ca2+ from the intracellular stores. Further to this effect, 2‐CAD had a major inhibitory effect on voltage‐operated Ca2+ channels compared with receptor‐operated Ca2+ channels.5 It can be concluded that adenosine through its A2 receptor produces vasorelaxant effect by interfering with the release of Ca2+ from the intracellular stores coupled with influx of Ca2+ from the extracellular sources.
Iono‐Covalent Character of the Metal–Oxygen Bonds in Oxides: A Comparison of Experimental and Theoretical Data
Authors: Lenglet M. 
Published: December 2003

The aim of this paper is to review the actual data on the chemical bond in binary and mixed oxides. The electronegativity (χM)
and the acidity pa
scales are the most significant semi‐empirical concepts for predicting
the trend of bonding character in iono‐covalent oxides. A satisfactory correlation between the data issued from the acidity scale and the calculated ionic charges has been established.The most recent studies show that the hybrid methods such as the B3LYP method lead to more reliable results for the description of structural, energetic and electronic properties of binary oxides than those from standard methods.
Substance use and the prediction of young offender recidivism
Authors: PUTNIŅŠ ALDIS L. 
Published: December 2003

AbstractThe problem considered is whether self‐reported substance use can be used in the estimation of recidivism risk among youths placed in secure care. The Secure Care Psychosocial Screening (SECAPS) and offending records of 447 youths admitted to detention centres in South Australia were examined. The target outcome was any new offending within 6 months of release. Use of a psychoactive substance at the time of committing the most recent offence was not a significant predictor of subsequent offending, nor was acknowledging having a problem with drug or alcohol use. In relation to the recent use of alcohol, marijuana, hallucinogens, sedatives/hypnotics, narcotics, stimulants and inhalants, only the use of alcohol and inhalants appeared to have significant relationships with recidivism. While the relationships were too small to permit using these items on their own to estimate re‐offending risk, recent alcohol and inhalant use could be included as part of a broader recidivism risk assessment.
Health and well‐being outcomes for drug‐dependent offenders on the NSW Drug Court programme
Authors: FREEMAN KAREN 
Published: December 2003

AbstractGiven the centrality of drug treatment to the drug court framework, the proliferation of drug courts in the United States, and their emergence more recently in Australia, it is surprising that such little attention has been given to assessing their therapeutic effect. This evaluation aimed to assess the health and well‐being of drug‐dependent offenders diverted to the New South Wales Drug Court, and monitor changes in their health and well‐being throughout 12 months of programme participation. The study consisted of baseline interviews with 202 offenders accepted into the programme between February 1999 and April 2000, and follow‐up interview at 4, 8 and 12 months with participants who remained on the programme. Health and well‐being was assessed at each follow‐up using the Short Form‐36 Health Survey (SF‐36) the OTI social functioning scale, and self‐reported spending as a proxy for illicit drug use. The health of male Drug Court participants prior to commencing the programme was significantly poorer than Australian population norms. The results provided evidence of significant and sustained improvements in health and well‐being for the 51 participants who competed each follow‐up interview. Furthermore, significant improvements were found for offenders who remained on the programme for at least 4 months but less than 12 months. However, the positive health outcomes are limited by the low programme retention rate. These results indicate that significant health outcomes can be achieved for at least some heavily drug‐dependent, recidivist offenders through the drug court model.
General practitioners' diagnostic skills and referral practices in managing patients with drug and alcohol‐related health problems: implications for medical training and education programmes
Authors: FUCITO USA M. , GOMES BRUNO S. , MURNION BRIDIN , HABER PAUL S. 
Published: December 2003

AbstractThe aim of this study was to determine the current practices of established general practitioners in managing patients with drug and alcohol‐related problems and identify gaps in training. A random sample of general practitioners completed a survey assessing diagnostic skills and referral practices concerning alcohol and illicit drug use in general practices in February 1999, comprising 110 general practitioners registered with the Central Sydney Division of General Practice. The main outcome measures were competent skills and knowledge, willingness to treat. The majority (96%) of GPs provided clinically appropriate responses for at least one drug category, although none received this rating for all six. Most general practitioners reported that they were unwilling to treat heroin and cocaine problems themselves but expressed willingness to refer patients appropriately. More than a quarter of general practitioners were unaware of the safe drinking levels for men and women or the appropriate treatment for patients consuming above such levels. Age, years in practice, type of practice, willingness to obtain drug use histories and post‐graduate training were all significantly associated with general practitioners' willingness to treat and competence in managing drug and alcohol‐related problems. In this study, general practioners reported low levels of skills and referrals for treatment of illicit drug use and suboptimal skills in the management of alcohol problems. The results suggest that a more comprehensive approach to education and training is required to bring about a change in practice behaviour.