bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measles vaccination improves the equity of health outcomes: evidence from Bangladesh
Authors: Bishaia David , Koenig Michael , Khan Mehrab Ali 
Published: April 2003

AbstractObjectives: This paper asks whether measles vaccination can reduce socioeconomic differentials in under five mortality rates (U5MR) in a setting characterized by extreme poverty and high levels of childhood mortality. Design: Longitudinal cohort study based on quasi experimental design. Setting: Data come from the phased introduction of a measles vaccine intervention in Matlab, Bangladesh in 1982. Subjects: There were 16 270 Bangladeshi children aged 9–60 months. Intervention: The intervention cohort received measles vaccine. Main outcome measures: Socioeconomic differentials in U5MR between the lowest and highest socioeconomic status (SES) quintiles in a cohort of 8135 vaccinated children and a cohort of unvaccinated age matched controls. Mantel–Haenszel rate ratios for the lowest to highest SES quintile were computed. SES was measured by factor analysis of maternal schooling, land holdings, dwelling size, and number of rooms. Results: The U5MR ratio of lowest SES to highest was 2.27 (95% CI=1.62–3.19) in the unvaccinated population and 1.42 (95%CI=0.94–2.15) in the vaccinated population. The difference between unvaccinated and vaccinated U5MR ratios was statistically significant (p<0.10) and robust across alternative measures of SES. Conclusion: Children from the poorest quintile were more than twice as likely to die as those from the least quintile in the absence of measles vaccination. Universal distribution of measles vaccination largely nullified SES related mortality differentials within a high mortality population of children. Copyright © 2002 John Wiley & Sons, Ltd.
The Aral Sea basin—rumors, realities, prospects
Authors: Dukhovny Victor A. 
Published: April 2003

AbstractThe Aral Sea basin has been for many years appearing in global and former Soviet mass media as an example of the rapacious attitude to nature on the part of socialist society. For the last 10 years Central Asia has been subsisting and surviving under conditions where the regional countries closely interact with the whole world community. Though the Aral Sea Program, which was laid down at the Paris meeting in 1994, remained generally unfulfilled, cooperation between Central Asian states as to joint water resources management has not only managed to survive but continues to develop. New rumors still continue to stigmatize the Aral Sea basin by overstressing current controversies that are allegedly ready to develop into a “war for water” in the region. As a matter of fact cooperation between the countries carried out by water management agencies and the Interstate Commission for Water Coordination (ICWC), which celebrated its tenth jubilee in February 2002, has been progressing regardless of complexities and differences in the environmental, social, political and natural situation in the countries and gaps between their levels of development. This cooperation enjoys the confidence of their future success, giving objective appraisal of achievements and drawbacks as well as ways to survive. Fair assessments and realistic approaches are needed on the part of those who are earnestly willing to help the region, and at the very least there should be noninterference and silence on the part of those who are not interested. Copyright © 2003 John Wiley & Sons, Ltd.
A computational study of interactions between acetic acid and water molecules
Authors: Yamabe Shinichi , Tsuchida Noriko 
Published: April 2003

AbstractDensity functional theory calculations were performed for the title reactions to elucidate the difference between the strong cyclic hydrogen bond of (MeCOOH)2 and the electrolytic dissociation, MeCOOH⇌MeCOO− + H+, as a weak acid. The association of water clusters with acetic acid dimers strengthens the cyclic hydrogen bond. A nucleophilic attack of the carboxylic carbon by a water cluster leads to a first zwitterionic intermediate, MeCOO− + H3O+ + (HO)3CMe. The intermediate is unstable and is isomerized to a neutral interacting system, MeCOOH…(HO)3CMe + H2O. The ethanetriol, (HO)3CMe is transformed to an acetic acid monomer. The monomer may be dissociated to give a second zwitterionic intermediate with reasonable proton‐relay patterns and energy changes. In proton relay reaction channels, H in MeCOOH is not an acidic proton but is always a hydroxy proton. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 939–947, 2003
Theoretical studies on the gas‐phase pyrolysis of 2‐phenoxycarboxylic acids: An ONIOM approach
Authors: Xue Ying , Kang Chun Ho , Kim Chan Kyung , Lee Ikchoon 
Published: April 2003

AbstractVarious ONIOM combinations—ONIOM(HF/6‐31G*: PM3), ONIOM(B3LYP/6‐31G*: PM3), ONIOM(MP2/6‐31G*: PM3), and ONIOM(MP2/6‐31G*: HF/3‐21G)—were applied to investigate thermal decomposition mechanisms of four 2‐phenoxycarboxylic acids (2‐phenoxyacetic acid, 2‐phenoxypropionic acid, 2‐phenoxybutyric acid, and 2‐phenoxyisobutyric acid) in the gas phase. All the transition states and intermediates of the reaction paths were optimized. The reaction pathway of four reactants yielding the phenol, CO, and the corresponding carbonyl compound was characterized on the potential energy surface and found to proceed stepwise. The first step corresponds to the elimination of phenol and the formation of α‐lactone intermediate through a five‐membered ring transition state, and the second step is the cycloreversion process of α‐lactone intermediate to form CO and the corresponding carbonyl compound. The reaction pathway of latter three compounds to produce the carboxylic acid and phenol via a four‐membered cyclic transition structure was also examined theoretically. Comparison with experiment indicates that the activation parameters for the fist reaction channel are accurately predicted at the ONIOM(MP2/6‐31G*: HF/3‐21G) level of theory. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 963–972, 2003
Feedback‐assisted three‐dimensional reconstruction of the left ventricle with MRI
Authors: Swingen Cory M. , Seethamraju Ravi Teja , Jerosch‐Herold Michael 
Published: April 2003

AbstractPurposeTo develop and test a new technique for rapid, accurate three‐dimensional (3D) reconstruction of the left ventricle (LV) and calculation of its volume parameters, with images from multiple orientations and interactive feedback.Materials and MethodsThe ventricular surface was fit to a number of user‐placed guide points in magnetic resonance (MR) images using bivariate smoothing splines. A 3D model was reconstructed and the LV volumes were calculated at both end diastole (ED) and end systole (ES). This technique was validated using a phantom, and applied to studies of 18 patients and four volunteers (N = 22) imaged on a 1.5‐T clinical scanner. The results of the 3D method were compared to the standard 2D short‐axis slice summation technique, which is widely used for the analysis of cardiac function.ResultsThere was excellent agreement between the computed volume of the phantom using the 3D modeling method and the actual volume (190.50 mL ± 3.06 mL, and 191.0 mL ± 2.5 mL, respectively). There was good correlation between the volumes calculated with our 3D model and the slice summation technique (ED volume (EDV) difference, 6.36% ± 8.99% [mean ± SD]; ES volume (ESV), 0.92% ± 14.75%; stroke volume (SV), 10.54% ± 13.95%; ejection fraction (EF), 4.22% ± 9.16%). The 3D method was found to be more accurate than the slice summation technique for calculating LV volumes and mass from images of different slice orientations. Variations in the parameters between the two separate orientations using the 3D model vs. the slice summation method were as follows: EDV: 2.11% ± 1.52% vs. 10.36% ± 9.33%; ES volume: 2.76% ± 1.64% vs. 6.39% ± 3.62%; SV, 3.02% ± 4.38% vs. 18.84% ± 15.30%; EF, 2.03% ± 2.16% vs. 8.58% ± 6.73%; and LV mass: 4.77% ± 2.41% vs. 24.59% ± 6.41%. Differences in the ES volume due to the inclusion or exclusion of the most basal slice were found to be lower with the 3D model (6.90% ± 3.83%) compared to the slice summation method (25.04% ± 6.15%).Conclusion3D models can be used to accurately determine ventricular volume parameters. Results can be obtained using images from a variety of orientations, providing greater flexibility during image acquisition and possibly reducing the number of images needed for analysis. Feedback is provided to assist the analysis by providing a continuous update of the LV shape and volume. This feature allows the user to determine LV parameters to a predefined accuracy or to terminate the analysis when the parameters are not changing. This method is not restricted to multislice cine imaging in a single or prescribed slice orientation, and can be used for quick, accurate, and interactive analysis of cardiac function. J. Magn. Reson. Imaging 2003;17:528–537. © 2003 Wiley‐Liss, Inc.
Comparing Strategies for the Synthesis of Polyolefinic Thermoplastic Elastomers via Macromonomer Incorporation
Authors: Haag Monica C. , Simon Leonardo C. , Soares Joao B. P. 
Published: April 2003

AbstractThe microstructure of polyolefinic thermoplastic elastomers made with a combination of two single‐site catalysts was analyzed by Monte Carlo simulation. The model can be used to describe the crystallizable fraction for both long‐chain branched polypropylene (aPP‐g‐iPP) and long‐chain branched ethylene/α‐olefin copolymers (PEαO‐g‐PE). The simulations showed that at levels of 7.5% of comonomer incorporation, PEαO‐g‐PE samples reach a similar crystallizability level of aPP‐g‐iPP. From a topological point of view, it was demonstrated that the fraction of free arms and inner segments tend to the limit of ½ for highly branched chains and that the fraction of free arms reaches its maximum value when the Y‐type chains are the predominant population. A mathematical correlation between the linear‐ and LCB catalyst probabilities was proposed to ensure the production of symmetrical branched chains.Long‐chain branch architecture of PEαO‐g‐PE.magnified imageLong‐chain branch architecture of PEαO‐g‐PE.
Effect of current and voltage leads on the superconducting properties of mesoscopic triangles
Authors: Morelle M. , Bruynseraede Y. , Moshchalkov V. V. 
Published: April 2003

AbstractThe superconducting/normal phase boundary of mesoscopic triangles is studied by transport measurements. The presence of voltage and current leads, intrinsic to transport measurements, may produce pronounced resistance peaks close to the normal/superconducting transition. These phenomena are explained by taking into account the presence of charge imbalance around superconducting/normal interfaces. The resistance peaks in the vicinity of Tc can be suppressed by choosing the right shape for the current and voltage contacts. The measured critical temperature Tc(H) is compared with recent theoretical curve obtained in the framework of the linearized Ginzburg–Landau theory. A good agreement between the theory and our experiments is found.
Activated escape over oscillating barriers: The case of many dimensions
Authors: Lehmann J. , Reimann P. , Hänggi P. 
Published: April 2003

AbstractWe present a novel path‐integral method for the determination of time‐dependent and time‐averaged reaction rates in multidimensional, periodically driven escape problems at weak thermal noise. The so obtained general expressions are evaluated explicitly for the situation of a sinusoidally driven, damped particle with inertia moving in a metastable, piecewise parabolic potential. A comparison with data from Monte‐Carlo simulations yields a very good agreement with our analytic results over a wide parameter range.
A Hierarchical QSAR Model for Urinary Excretion of Drugs in Humans as a Predictive Tool for Biotransformation
Authors: Manga Na'ngono , Duffy Judith C. , Rowe Philip H. , Cronin Mark T. D. 
Published: April 2003

AbstractOf the many pharmacokinetic endpoints applicable to in silico screening, drug biotransformation seen as a hybrid, multi‐enzymatic disposition parameter, has been little addressed. The aim of this study was to model drug biotransformation, utilising metabolism data for a heterogeneous group of drugs. The data were the cumulative amount of unchanged drug excreted in the urine, expressed as percent of the intravenous dose, administered for 160 drugs. The data were categorised into classes according to excretion ranges. The cut‐off values between those ranges were defined so as to enable optimal modelling. For each drug, a total of 72 physicochemical and structural descriptors were calculated. Modelling of the drug metabolism data was attempted utilising a hierarchical approach comprising a set of rules combining both linear discriminant analysis and recursive partitioning. The model developed into a decision tree involving the following descriptors: LogD6.5, counts of H‐bond donors, ionisation potential, COSMIC total energy, electronic energy, counts of OH‐groups and COOH‐groups and the sum of the total net charges. Overall, this model assigned 90% of the compounds correctly to the categories of extensively, or non‐extensively, metabolised. The model was successfully validated using an external test set of 40 compounds.
Mitogenic activity of insulin in the culture of a trypanosome: duration and dose response
Authors: Mackintosh David , Coleman Kim , Davies Angela J 
Published: April 2003

AbstractThe effects of insulin on the in vitro growth characteristics of Trypanosoma granulosum were investigated. The insulin growth stimulus had a rapid onset with little or no lag phase but was relatively short lived, growth peaking typically on day 3 or 4 of culture. This contrasted with medium containing 10% foetal calf serum, normally used for in vitro culture of this trypanosome, which after a 3 day lag stimulated sustained log‐phase growth. Insulin demonstrated a biphasic dose response with maximum growth typically occurring at 3–10 μg/ml and a much reduced effect at higher concentrations. These findings suggest a possible role for host insulin and/or trypanosomal insulin‐like molecules in regulating parasite growth in vivo.
DPP IV resistance and insulin releasing activity of a novel di‐substituted analogue of glucose‐dependent insulinotropic polypeptide, (Ser2–Asp13)GIP
Authors: Gault V.A. , Irwin N. , Harriott P. , Flatt P.R. , O'Harte F.P.M. 
Published: April 2003

AbstractStructure—function studies suggest that preservation of the N‐terminus and secondary structure of glucose‐dependent insulinotropic polypeptide (GIP) is important for biological activity. Therefore, a novel di‐substituted analogue of GIP, (Ser2–Asp13)GIP, containing a negatively charged Asp residue in place of an Ala in position 13, was synthesised and evaluated for in vitro biological activity. Incubation with dipeptidyl peptidase IV (DPP IV) showed the half‐lives of GIP and (Ser2–Asp13)GIP to be 2.3 and >4 h, respectively. Insulin releasing studies in clonal pancreatic BRIN‐BD11 cells demonstrated that (Ser2–Asp13)GIP (10−12to 10−7mol/l) was significantly less potent (60–90%; P<0.05 to P<0.001) than native GIP. The peptide failed to display antagonistic properties as it did not significantly alter insulin secretion when incubated in the presence of GIP (10−7 mol/l). These results demonstrate that despite increased resistance to DPP IV, substituting Ala in position 13 with a negatively charged Asp, thus producing the di‐substituted analogue (Ser2–Asp13)GIP, significantly reduces biological activity, most likely due to modifications within the secondary structure.
Altägyptische Rezepturen metrologisch neu interpretiert
Authors: Pommerening Tanja 
Published: April 2003

AbstractStarting point of this article is a problem obvious to anybody who reads the medical papyri of ancient Egypt from the New Kingdom and the Late Period: the prescriptions contain two dyadic systems of notation for measures of capacity without specifying the unit of measurement, firstly the Horus eye fractions 1/2, 1/4, 1/8, 1/16, 1/32 and 1/64 which are unanimously assumed to refer to the single Heqat and secondly the ‘normal’ dyadic fractions from 1/2 to 1/128, which have been interpreted in widely different ways, as fractions of the Henu‐, the Ro‐, the single Heqat‐, the 5‐Ro‐ or the Dja‐measure, respectively. Interpretations suggested in translations and commentaries have remained inconclusive and unsatisfactory. Based on new findings and readings, the present study sets out to show that•the hieratic Horus eye fractions in the medical papyri of the New Kingdom and the Late Period refer to the quadruple and not to the single Heqat;•the ‘normal’ fractions refer to the smallest Horus eye fraction 1/64 quadruple Heqat which corresponds from the New Kingdom (at the latest) to 1 Dja;•the units Dja and Henu are in a ratio of 5:8 and not of 2:3, this unusual ratio of 5:8 makes sense in Egyptian thought when expressed as 40:64; 40 Henu (= 1 Oipe = 1 quadruple Heqat) equal 64 Dja and therefore the complete Horus eye, the smallest fraction of the Horus eye, 1/64 is 1 Dja;•hence, the capacity markings of the two complete vessels known to exist with marked volumes of 1 and 1/2 Henu and 1, 1/2, 1/4, 1/8, 1/16, 1/32 and 1/64 Dja, allow all relevant volumes to be measured which are required in the preparations mentioned in extant medical papyri.
Very Rapid Preparation of SmI2 by Sonic Treatment of Iodoform and Metallic Samarium
Authors: Concellón José M. , Rodríguez‐Solla Humberto , Bardales Eva , Huerta Mónica 
Published: April 2003

AbstractA very rapid preparation of SmI2 by sonication of a mixture of metallic samarium and iodoform in THF is described. To prove the synthetic applications of the obtained SmI2 several high‐yielding reactions were carried out. Preliminary results for the generation of SmI2 in THF by sonication from diiodomethane, 1,2‐diiodoethane, or iodine are also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Immobilization of heavy metals in soils using inorganic amendments in a greenhouse study
Authors: Friesl Wolfgang , Lombi Enzo , Horak Othmar , Wenzel Walter W. 
Published: April 2003

AbstractThe effect of red mud (10 g kg–1), a by‐product of the alumina industry, zeolite (20 g kg–1), a naturally‐occurring hydrous aluminosilicate, and lime (3 g kg–1) on metal lability in soil and uptake by fescue (Festuca rubra L.) (FEST) and amaranthus (Amaranthus hybridus L.) (AMA) was investigated in four different soils from Austria. The soil collection locations were Untertiefenbach (UNT), Weyersdorf (WEY), Reisenberg (REI), and Arnoldstein (ARN). The latter was collected in the vicinity of a former Pb‐Zn smelter and was highly polluted with Pb (12300 mg kg–1), Zn (2713 mg kg–1), and Cd (19.7 mg kg–1) by long‐term deposition. The other soils were spiked with Zn (700 mg kg–1), Cu (250 mg kg–1), Ni (100 mg kg–1), V (100 mg kg–1), and Cd (7 mg kg–1) salts in 1987. The two plant species were cultivated for 15 months. Ammonium nitrate (1 M) extraction was used in a soil : solution ratio of 1:2.5 to assess the influence of the amendments on the labile metal pools. The reduction of metal extractability due to red mud was 70 % (Cd), 89 % (Zn), and 74 % (Ni) in the sandy soil (WEY). Plant uptake in this treatment was reduced by 38 to 87 % (Cd), 50 to 81 % (Zn), and 66 to 87 % (Ni) when compared to the control. Sequential extraction revealed relative enrichments of Fe‐oxide‐associated metal fractions at the expense of exchangeable metal fractions. Red mud was the only amendment that decreased lability in soil and plant uptake of Zn, Cd, and Ni consistently. Possible drawbacks of red mud application (e.g., As and Cr concentration) remain to be evaluated.
Monte Carlo Simulation of Long‐Chain Branched Polyethylene Chains Synthesized with Dual‐Site‐Type Catalyst Systems
Authors: Beigzadeh Daryoosh 
Published: April 2003

AbstractA Monte Carlo model for the polymerization of ethylene with long‐chain branch formation using dual‐site catalyst systems was developed. It was shown that, unlike single‐site catalyst systems, a detailed knowledge of the specifics of catalyst sites and reactor conditions is essential to determine the required probabilities. Therefore, a kinetic model was developed for a CSTR at steady state to simulate the polymerization process. A methodology was also proposed for the calculation of the seven required Monte Carlo model probabilities from the kinetic model. It was shown how the information obtained from the Monte Carlo model complemented the kinetic model results in mapping out the chain microstructure and modeling the polymerization reactor. Eight different dual‐site catalyst systems were simulated to evaluate the proposed methodology.
Flow chart of the computer program for the Monte Carlo model for the simulation of LCB chains with dual‐site catalyst systems.magnified imageFlow chart of the computer program for the Monte Carlo model for the simulation of LCB chains with dual‐site catalyst systems.
Predicting Toxicity against the fathead Minnow by Adaptive Fuzzy Partition
Authors: Pintore Marco , Piclin Nadège , Benfenati Emilio , Gini Giuseppina , Chrétien Jacques R. 
Published: April 2003

AbstractRecent progress in the development of powerful tools suitable to design and to classify large chemical libraries can be fruitfully extended also to the ecotoxicity domain. Amidst these methods, Fuzzy Logic concepts, based on the possibility to handle the “concept of partial truth”, constitute interesting approaches to developing general predictive models.
Liquid chromatography/tandem mass spectrometry for the identification and determination of trichothecenes in maize
Authors: Laganà Aldo , Curini Roberta , D'Ascenzo Giuseppe , De Leva Ilaria , Faberi Angelo , Pastorini Elisabetta 
Published: April 2003

AbstractA reliable, sensitive and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to determine four trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon X and 3‐acetyldeoxynivalenol) in maize. Sample preparation was performed by extracting the analytes with a mixture of acetonitrile and water, followed by a solid‐phase extraction with Carbograph‐4 cartridges as the purification step. For the LC/MS/MS analysis two interfacing systems, Turbo IonSpray (TISP) and atmospheric pressure chemical ionization (APCI), were compared in both negative and positive ion modes. LC and MS parameters were optimized to achieve better results and sensitivity. The effect of mobile phase modifiers such as ammonium acetate and formic acid on the ionization yield was also evaluated. The best results were obtained using the electrospray ionization (ESI) interface in negative ion mode and the multiple reaction monitoring mode (MRM) for the quantitation. The detection limits ranged between 10 ng/g for fusarenon X and 1.5 ng/g for deoxynivalenol. A linear working range was achieved with a standard deviation between 3 and 10% and recovery rates from the maize samples above 81%. The procedure was applied to the analysis of a set of maize samples collected from farms located in different areas of northern and central Italy. The investigated samples turned out to be contaminated primarily with deoxynivalenol and, to a minor extent, with its derivatives. Copyright © 2003 John Wiley & Sons, Ltd.