bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics and Mechanism of Acid-Catalyzed Decomposition of 1,3-Bis(4-methylphenyl)triazene in Hexane-Organic Acid Medium
Authors: Ludwig Miroslav , Kabíčková Miriam
Published: July 2002

The kinetics of acid-catalyzed decomposition of 1,3-bis(4-methylphenyl)triazene have been studied in mixtures of hexane and organic acid of various ratios using acetic, isovaleric, and pivalic acids as the catalysts. In all the cases, a monotonously increasing dependence of the observed rate constant upon mol fraction of the acid has been found. The results obtained are discussed with the help of the classic third- and fourth-order functions by Margules and the respective kinetic model. The main catalyzing particle appears to be the dimer of the respective acid, the reaction probably going via a complex formed by two molecules of acid and one molecule of the triazene.
Physicochemical and Catalytic Properties of Spinels Formed by Solid-Solid Interaction Between Fe2O3and V2O5
Authors: Said Abd El-Aziz Ahmed
Published: July 2002

Vanadium oxide catalysts doped or mixed with 1-50 mole % Fe3+ ions were prepared. The structure of the original samples and those calcined from 200 up to 500 °C were characterized by TG, DTA, IR and X-ray diffraction. The SBET values and texture of the solid catalysts were investigated. The catalytic dehydration-dehydrogenation of isopropanol was carried out at 200 °C using a flow system. The results obtained showed an observable decrease in the activity of V2O5 on the addition of Fe3+ ions. Moreover, Fe2V4O13 is the more active and selective catalyst than FeVO4 spinels. The results were correlated with the active sites created on the catalyst surface.
N2O in NO Reduction by CO Over Pt/NaX Zeolite
Authors: Nováková Jana , Kubelková Ludmila
Published: July 2002

Pt/NaX zeolite (3 Pt atoms per unit cell) was prepared by vacuum decomposition of [Pt(NH3)4]2+. NO + 13CO and N2O + 13CO reactions were studied under static conditions at 180, 205 and 230 °C and followed by temperature programmed desorption (TPD) of surface species adsorbed in zeolites during the reaction. The effect of different NO/CO ratios and of the added oxygen was examined for the former reaction. The experimental results agree with the assumption that N2O (and 13CO2) is (are) the primary product(s) released into the gaseous phase below 230 °C; above 205 °C, the complete reduction to N2 occurs. N2O could be a very rapidly decomposing surface intermediate for this complete reduction, and can act together with the recombination of N atoms. Nitrous oxide released into the gas phase cannot serve as the reaction intermediate, because its reduction by CO proceeds much more slowly than that of NO. The formation of nitrous oxide in the NO + CO reaction is, in addition to low temperatures, enhanced by the increased NO/CO ratio and by the presence of oxygen. The latter effect can be due to the occupation of Pt active sites by adsorbed oxygen and/or by the oxidation of NO to higher oxides which decompose, yielding N2O (together with NO and oxygen).
Synthesis and Crystal Structures of Dimeric Titanium(II) Bis(trimethylsilyl)acetylene Complexes [(C5H5-nMen)Ti(η2-Me3SiC≡CSiMe3)(μ-Cl)]2(n = 3-5)
Authors: Hiller Jörg , Thewalt Ulf , Podlaha Jaroslav , Hanuš Vladimír , Mach Karel
Published: July 2002

Crystalline Ti(II) complexes [(C5H5-nMen)Ti(η2-Me3SiC≡CSiMe3)(μ-Cl)]2 (n = 3-5) (1-3) were prepared by reduction of the appropriate cyclopentadienyltitanium trichlorides (C5H5-nMen)TiCl3 in tetrahydrofuran by one equivalent of magnesium in the presence of at least one equivalent of bis(trimethylsilyl)acetylene. The X-ray structure analyses of 1-3 revealed that all compounds form chlorine-bridged centrosymmetric dimers.
Kinetics and Mechanism of Cyclization of Substituted 2-(Benzoylamino)alkanamides in Strongly Basic Medium
Authors: Sedlák Miloš , Kaválek Jaromír , Mitaš Petr , Macháček Vladimír
Published: July 2002

The cyclization reaction of substituted 2-(benzoylamino)alkanamides 1a-1i giving the corresponding substituted 2-phenylimidazol-4(5H)-ones 2a-2i has been studied. The equilibrium constants of reactions of compounds 1d-1f and 2-[(4-nitrobenzoyl)amino]-2,3-dimethylbutanenitrile (3) with methoxide have been determined in methanol-dimethyl sulfoxide media. For compound 1d and N-methyl derivatives 1a-1c, the cyclization rate constants have been measured in dependence on methoxide concentration in media of varying contents of dimethyl sulfoxide. The cyclization reaction mechanism involves formation of anion in a rapid pre-equilibrium and subsequent rate-limiting step: either formation of a cyclic intermediate or splitting off of OH- ion from this intermediate. The product formed in the given medium is immediately transformed into its conjugate base. A change in reaction medium affects the reactions of all the compounds in the same way. The ratio of concentration of substrate to that of its anion at low methoxide concentrations is affected by the solvent composition (MeOH-DMSO). At higher methoxide and DMSO concentrations the reaction rate distinctly decreases, which can be interpreted by the transformation of reactive anion into non-reactive dianion. The corresponding N-methylbenzoylamino compounds are cyclized faster by a factor of 400 as compared with compounds having no methyl group at the benzamide group.
Reactivity of Halo Sugars on Silver Cathodes
Authors: Rondinini Sandra B. , Mussini Patrizia R. , Crippa Federico , Petrone Michela , Sello Guido
Published: July 2002

Our extensive research on the reductive electrochemistry of glycosyl derivatives has revealed a remarkable electrocatalytic activity of silver cathodes in the reduction of glycosyl halides, which is strictly related to both the electrode active surface and the reaction medium. The peculiarities exhibited by silver cathodes have been extensively characterised (i) by reactivity studies performed on a wide range of halo sugars by cyclic voltammetry and (ii) by preparative electrolyses leading to the formation of simple and mixed glycosyl dimers and, in the presence of suitable acceptors, of glycosides and glycosyl compounds.
Reductive Nitrosylation of V2O5 and MoO3 with Hydroxylamine in the Presence of 1,4,7-Triazacyclononane
Authors: Hauser Christina , Weyhermüller Thomas , Wieghardt Karl
Published: July 2002

From the reaction mixture of an alkaline aqueous solution of V2O5, 1,4,7-triazacyclononane (tacn) and hydroxylamine, orange, diamagnetic crystals of [V(tacn)(NO)2(NH3)]I were obtained upon addition of NaI. Air-stable [V(tacn)(NO)2(N3)] has also been isolated and characterized by X-ray crystallography. In a similar reaction using MoO3 as starting material, yellow crystals of [MoCl(tacn)(NO)(H2NO)]ClO4 were isolated and characterized by X-ray crystallography. A less reducing reagent, N-methylhydroxylamine, produces in the above reaction mixture colorless crystals of [MoVI(tacn)(O)2(MeNHO)]ClO4; its structure has also been determined. A mechanism for the formation of {M(NO)2}6 complexes (M = Mo, V) from high-valent oxometallates and hydroxylamine is proposed.
To the Mechanism of Horseradish Peroxidase-Mediated Degradation of a Recalcitrant Dye Remazol Brilliant Blue R
Authors: Mikšanová Markéta , Hudeček Jiří , Páca Jan , Stiborová Marie
Published: July 2002

Thein vitroenzymatic metabolism of a recalcitrant dye Remazol Brilliant Blue R (RBBR) was investigated using horseradish peroxidase (HRP). At optimum pH (4.5), the apparent Michaelis constant (KM) value for the oxidation of RBBR catalyzed by HRP is 14.8 μmol l-1. HRP-mediated conversion of RBBR proceedsviaa conventional peroxidase reaction, by a sequential one-electron oxidation of two molecules of RBBR by the peroxidase Compounds I and II. The oxidation is inhibited by radical trapping agents (nicotinamide adenine dinucleotide reduced (NADH), ascorbate, glutathione). This confirms that the peroxidase-mediated oxidation of RBBR proceedsviaradical mechanism. Gel permeation profile of the RBBR oxidation products shows that the pattern of molecular weight distribution was shifted to the higher molecular weight region indicating formation of RBBR oligomers. In addition to HRP, the RBBR dye is also oxidized by another peroxidase, the mammalian lactoperoxidase.
Resonance Energy in Benzene Derivatives with a Variable Functional Group
Authors: Exner Otto , Böhm Stanislav
Published: July 2002

Three isodesmic reactions were investigated in which a variable substituent is transferred from a saturated to an unsaturated hydrocarbon residue: ethane → ethene, methane → benzene, ethane → benzene. Their reaction energies could serve as a measure of substituent resonance ability. They were calculated for 31 substituents by the density functional theory (DFT) at the B3LYP/6-311+G(d,p) level, and served as a model for systematic comparison of the DFT energies and experimental enthalpies of formation ∆fH°(298). It turned out that calculations at this level are more reliable than experiments; they disagree sometimes with ∆fH°(298) measured at different times and in different laboratories but agree better with the values calculated by simple additive scheme. Some particularly suspicious values were pointed out. The DFT reaction energies of the isodesmic reactions, ∆1E-∆3E, were correlated with the standard scales of resonance and with other scales of substituent effects by multiple linear regression and principal component analysis. The three scales are fairly similar to each other (correlation coefficients 0.68-0.83), depend rather strongly on resonance (75% of the variance) but involve still at least one component which could not be explained in terms of common substituent effects. Certainly they do not depend - not even slightly - on the inductive effect, steric effect or polarizability.
Utilisation of 6-Amino-2,3-dimethylquinoxaline for the Synthesis of Tricyclic Pyridoquinoxalines via Gould-Jacobs Reaction
Authors: Saloň Jozef , Milata Viktor , Prónayová Nadežda , Leško Ján
Published: July 2002

Treatment of 2,3-dimethylquinoxalin-6-amine with (alkoxymethylidene)malonic derivatives gave the corresponding (quinoxalylamino)ethenes, which on heating cyclized to angularly annelated pyrido[3,2-f]quinoxalin-10-ones.
Hyperhomocysteinaemia and MTHFR C677T gene polymorphism in renal transplant recipients
Authors: Szabó A J , Tulassay T , Melegh B , Szabó T , Szabó A , Vannay Á , Fekete A , Süveges Z , Reusz G S
Published: July 2002

AIM

To study the effect of folate treatment on hyperhomocysteinaemia and the effect of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism on total homocysteine and folate concentrations after renal transplantation.

METHODS

A total of 30 transplanted children and adolescents were investigated for total homocysteine and folate serum concentrations before and after folate treatment, as well as for the presence of the MTHFR C677T polymorphism.

RESULTS

The allele frequency of C677T polymorphism in the MTHFR gene in the study population (0.33) was not different to that in controls (0.38). Before folate treatment the homocysteine concentration was raised in all groups; following folate supplementation it was significantly decreased in the CC and CT groups, but not in the TT group. In patients with CC genotype, serum homocysteine correlated with serum creatinine and cholesterol, and time since transplantation before treatment.

CONCLUSION

Folate supplementation appears to be an effective strategy to normalise total homocysteine concentration in renal transplanted children and adolescents.
Management of sickle cell priapism with etilefrine
Authors: Gbadoé A D , Atakouma Y , Kusiaku K , Assimadi J K
Published: July 2002

Intracavernous injections of etilefrine were effective in seven children with acute sickle cell priapism, and stuttering priapism resolved in five children after one to seven months of oral etilefrine. Compared with our previous reports in adults, etilefrine appears to be more effective in childhood.
Evidence based prevention of acute injuries during physical exercise in a WHO safe community
Authors: Timpka T , Lindqvist K
Published: July 2002

Objective—To evaluate a community based programme for evidence based prevention of injuries during physical exercise.

Design—Quasi-experimental evaluation using an intervention population and a non-random control population.

Participants—Study municipality (population 41 000) and control municipality (population 26 000) in Sweden.

Main outcome measures—Morbidity rate for sports related injuries treated in the health care system; severity classification according to the abbreviated injury scale (AIS).

Results—The total morbidity rate for sports related injuries in the study area decreased by 14% from 21 to 18 injuries per 1000 population years (odds ratio 0.87; 95% confidence interval (CI) 0.79 to 0.96). No tendency towards a decrease was observed in people over 40. The rate of moderately severe injury (AIS 2) decreased to almost half (odds ratio 0.58; 95% CI 0.50 to 0.68), whereas the rate of minor injuries (AIS 1) increased (odds ratio 1.22; 95% CI 1.06 to 1.40). The risk of severe injuries (AIS 3–6) remained constant. The rate of total sports injury in the control area did not change (odds ratio 0.93; 95% CI 0.81 to 1.07), and the trends in the study and control areas were not statistically significantly different.

Conclusion—An evidence based prevention programme based on local safety rules and educational programmes can reduce the burden of injuries related to physical exercise in a community. Future studies need to look at adjusting the programme to benefit all age groups.
An analysis of consultations with the crowd doctors at Glasgow Celtic football club, season 1999–2000
Authors: Crawford M , Donnelly J , Gordon J , MacCallum R , MacDonald I , McNeill M , Mulhearn N , Tilston S , West G
Published: July 2002

Objective—To analyse all clinical presentations to the crowd doctors at Scotland's largest football stadium over the course of one complete season.

Methods—A standard clinical record form was used to document all consultations with the crowd doctors including treatment and subsequent referrals. The relevance of alcohol consumption was assessed.

Results—A total of 127 casualties were seen at 26 matches, a mean of 4.88 per match. Twenty casualties were transferred to hospital, including one successfully defibrillated after a cardiac arrest. Alcohol excess was a major contributing factor in 26 cases.

Conclusions—The workload of the crowd doctors was very variable and diverse. The social problem of excessive alcohol consumption contributed considerably to the workload. The provision of medical facilities at football grounds means that attendance there is now one of the least adverse circumstances in which to have a cardiac arrest. The study confirmed previous impressions that more casualties are seen at high profile matches.
What is a natural cause of death? A survey of how coroners in England and Wales approach borderline cases
Authors: Roberts I S D , Gorodkin L M , Benbow E W
Published: July 2002

Aim—Many deaths fall in the “grey” area between those that are clearly natural and those that are unnatural. There are no guidelines to help doctors in dealing with such cases and death certification is often arbitrary and inconsistent. In an attempt to initiate debate on these difficult areas, and with the ultimate aim of achieving national consensus, the views of coroners in England and Wales were sought.

Methods—Sixteen clinical scenarios, with causes of death, were circulated to all coroners in England and Wales. For each case they were asked to provide a verdict, with explanation. The deaths fell into three groups: (1) postoperative, (2) a combination of trauma and natural disease, and (3) infectious disease.

Results—Sixty four questionnaires were returned. There was near consensus (> 80% concordance) in only two of the 16 cases. In five, there was no significant agreement between coroners in the verdicts returned (“natural causes” versus “misadventure/accidental”). These included all three cases in which death resulted from a combination of trauma and natural disease (a fall after a grand mal fit; falls resulting in fractures of bones affected by metastatic carcinoma and osteoporosis), bronchopneumonia after hip replacement for osteoarthritis, and new variant Creutzfeldt-Jakob disease. The comments made for each case indicate that the variation between coroners in whether or not to hold an inquest, and the verdict arrived at, reflect the lack of a definition for natural causes, together with differences in the personal attitudes of each coroner.

Conclusions—There is considerable variation in the way in which coroners approach these borderline cases, many of which are common in clinical practice. This study indicates a need for discussion, working towards a national consensus on such issues. It highlights the importance of good communication between coroners and medical staff at a local level.
Ethics and geographical equity in health care
Authors: Rice Nigel , Smith Peter C
Published: July 2002

Important variations in access to health care and health outcomes are associated with geography, giving rise to profound ethical concerns. This paper discusses the consequences of such concerns for the allocation of health care finance to geographical regions. Specifically, it examines the ethical drivers underlying capitation systems, which have become the principal method of allocating health care finance to regions in most countries. Although most capitation systems are based on empirical models of health care expenditure, there is much debate about which needs factors to include in (or exclude from) such models. This concern with legitimate and illegitimate drivers of health care expenditure reflects the ethical concerns underlying the geographical distribution of health care finance.
Peutz-Jeghers families unlinked toSTK11/LKB1 gene mutations are highly predisposed to primitive biliary adenocarcinoma
Authors: Olschwang Sylviane , Boisson Cécile , Thomas Gilles
Published: July 2002

INTRODUCTION

Germline mutations of theSTK11/LKB1 tumour suppressor gene (19p13.3) are responsible for Peutz-Jeghers syndrome (PJS), a rare genetic disorder, which is dominantly inherited. In addition to the typical hamartomatous gastrointestinal polyps and perioral pigmented lesions, PJS is also associated with the development of tumours in various sites. No specific follow up has yet been evaluated for gene carriers. Furthermore, genetic heterogeneity has been reported, which makes genetic counselling difficult.

METHODS

We report here the analysis of the STK11/LKB1 locus in a series of 34 PJS families, combining the search for mutations and rearrangements in the coding sequence, allele specific expression tests, and linkage studies.

RESULTS

Germline deleterious mutation of the STK11/LKB1 gene were identified in 70% of cases. The hypothesis of a second PJS locus was reinforced and PJS families could be divided into two groups on the basis of the presence or absence of an identifiedSTK11/LKB1 alteration. Analysis of clinical data indicates that the cancer associated risk is markedly different in the two groups. PJS patients with no identifiedSTK11/LKB1 mutation are at major risk for proximal biliary adenocarcinoma, an infrequent tumour in the general population.

CONCLUSION

Up to 30% of PJS patients are caused by mutation in an unidentified gene that confers high susceptibility to cancer development.
Haematological and spermatotoxic effects of ethylene glycol monomethyl ether in copper clad laminate factories
Authors: Shih Tung-Sheng , Hsieh An-Tsz , Liao Guo-Dong , Chen Yeong-Hwang , Liou Saou-Hsing
Published: July 2002

OBJECTIVES

To investigate the effects of ethylene glycol monomethyl ether (EGME) on haematology and reproduction in exposed workers.

METHODS

53 Impregnation workers from two factories that make copper clad laminate with EGME as a solvent were recruited as the exposed group. Another group of 121 lamination workers with indirect exposure to EGME was recruited as the control group. Environmental monitoring of concentrations of EGME in air and biological monitoring of urinary methoxyacetic acid (MAA) concentrations were performed. Venous blood was collected for routine and biochemical analyses. Semen was collected from 14 workers exposed to EGME for sperm analysis and was compared with 13 control workers.

RESULTS

Results of haematological examination showed that the haemoglobin, packed cell volume, and red blood cell count in the male workers exposed to EGME were significantly lower than in the controls. The frequency of anaemia in the exposed group (26.1%) was significantly higher than in the control group (3.2%). However, no differences were found between the female workers exposed and not exposed to EGME. After adjustment for sex, body mass index, and duration of employment, red blood cell count was significantly negatively associated with air concentrations of EGME, and haemoglobin, packed cell volume, and red blood cell count were significantly negatively associated with urinary concentrations of MAA. The pH of semen in the exposed workers was significantly lower than in the control workers, but there were no significant differences in the sperm count or sperm morphology between the exposed and control groups.

CONCLUSION

It can be concluded that EGME is a haematological toxin, which leads to anaemia in the exposed workers. However, the data from this study did not support the theory of a spermatotoxic effect of EGME.
Respiratory health effects from exposure to carbon black: results of the phase 2 and 3 cross sectional studies in the European carbon black manufacturing industry
Authors: Gardiner K , van Tongeren M , Harrington M
Published: July 2002

OBJECTIVES

To assess respiratory morbidity over several cross sectional phases in the European carbon black manufacturing industry.

METHODS

Participants completed an amended (and translated) MRC respiratory morbidity questionnaire with additional questions on previous exposures, job history, etc, and spirometry traces in each phase. Concurrent with the health outcome measures, personal exposure to inhalable dust was measured.

RESULTS

Percentage participation rose from 90% in phase 2 (19 factories) to 95% in phase 3 (16 factories). Exposure dropped slightly between the 2 and 3 phases; as did the prevalence of reporting symptoms. Percentage of predicted lung function volumes exceeded 100% for forced expired volume in 1 second (FEV1) and forced vital capacity (FVC), whereas forced mid-expiratory flow (FEF25%–75%) and FEV1/FVC ratio were below 100% in both phases. The multiple linear and logistic regressions showed that carbon black had a significant effect on lung function and on most respiratory symptoms, respectively.

CONCLUSION

Both current and cumulative exposure to carbon black have a deleterious effect on respiratory morbidity. Due to the drop in exposure between phases 2 and 3, recent exposures seem to have less of an impact on the respiratory morbidity in the workers in phase 3 than those in phase 2.
Psychological stress, anxiety, depression, job satisfaction, and personality characteristics in preregistration house officers
Authors: Newbury-Birch D , Kamali F
Published: July 2002

Work related stress and anxiety may have a profound effect on an individual’s wellbeing. In the case of doctors this may also affect patient care. This study measured stress, anxiety, and job satisfaction and the influence of personality factors on these in a group of preregistration house officers in the north east of England. A total of 109 preregistration house officers anonymously completed a lifestyles questionnaire designed to measure self rated psychological stress, state anxiety, job satisfaction, and personality characteristics. Results showed that 37.5% of women and 24% of men preregistration house officers suffered from possible psychological stress. Altogether 38.9% of women and 5.4% of men were suffering from possible anxiety and 8.3% of women and 2.7% of men were suffering from possible depression. The mean (SD) job satisfaction scores were 83.8(17.4) (range 52–127; median 86.5) for men and 80.5(16.7) (range 41–114; median 81) for women. Altogether 30.6% of men and 41.7% of women reported to be dissatisfied with the organisational processes in their job. There were significant negative correlations between stress and job satisfaction scores (r = −0.508; p<0.0001) and between anxiety and job satisfaction scores (r = −0.421; p<0.0001), and significant positive associations between anxiety and stress scores (r = 0.593; p<0.0001). Stress, anxiety, and depression scores were significantly correlated with neuroticism scores in both men and women. The personality characteristic of neuroticism was a predisposing factor for stress and anxiety in the junior doctors which may be taken into consideration when offering support and counselling.
Angiotensin converting enzyme inhibitor induced hyperkalaemic paralysis
Authors: Dutta D , Fischler M , McClung A
Published: July 2002

Secondary hyperkalaemic paralysis is a rare condition often mimicking the Guillain-Barré syndrome. There have been a few case reports of hyperkalaemia caused by renal failure, trauma, and drugs where the presentation has been with muscle weakness. A case of hyperkalaemic paralysis caused by an angiotensin converting enzyme inhibitor is reported.
Candida endophthalmitis: an unusual complication of prolonged intravenous access
Authors: Vose M , Beatty S , Charles S J
Published: July 2002

A 16 year old boy awaiting a defunctioning colostomy for Crohn’s disease complained of reduced vision in his left eye. Four weeks previously candida had been isolated from his central line used for parenteral feeds. Fundal examination of the left eye revealed a macular abscess with a classic “string of pearls” appearance of multiple vitreous abscesses. This was treated with pars plana vitrectomy and intravitreal antifungal therapy. Microbiological studies confirmed a diagnosis of candida endophthalmitis.
Parathyroid crisis in a 20 year old—an unusual cause of hypercalcaemic crisis
Authors: Wong P , Carmeci C , Jeffrey R B , Weigel R J
Published: July 2002

Since the advent of automated serum analysis, patients with primary hyperparathyroidism (PHPT) are often asymptomatic at presentation or have mild symptoms attributable to the disease. Parathyroid crisis is a rare and potentially fatal complication of PHPT in which patients develop severe hypercalcaemia with signs and symptoms of multiple organ dysfunction. A case of parathyroid crisis in a 20 year old man who presented with brown tumours and renal stones is described.
Comparative evaluation of the new Sheffield table and the modified joint British societies coronary risk prediction chart against a laboratory based risk score calculation
Authors: Rabindranath K S , Anderson N R , Gama R , Holland M R
Published: July 2002

Background

Management of borderline hypertension and hypercholesterolaemia is based on an individual’s coronary heart disease (CHD) risk rather than arbitrary values for blood pressure or serum cholesterol. Prediction of CHD risk involves using tables, charts, or computer programs based on the Framingham equations. The new Sheffield table and modified joint British societies coronary risk prediction (JBS) chart are widely used. The JBS chart approximates age and systolic blood pressure, and the new Sheffield table dichotomises blood pressure, and these simplifications may lead to diagnostic inaccuracy.

Methods

The diagnostic performance of the charts against an individualised laboratory based CHD risk calculation in 1102 subjects in primary care were evaluated and compared.

Results

The new Sheffield table and modified JBS chart performed equally well with a respective diagnostic sensitivity and specificity of 91.6% (95% confidence interval 86.7% to 95.1%) and 93.8% (91.1% to 97.9%), and 93.6% (90.4% to 96.0%) and 94.7% (92.6% to 96.1%) at 10 year CHD risk of 15%; and of 95.2% (82.8% to 99.4%) and 97.9% (96.8% to 98.7%), and 90.5% (75.6% to 97.4%) and 100% (99.7% to 100%) at 10 year CHD risk of 30%.

The modified JBS chart graphic display provides graded risk, which may be an advantage over the new Sheffield table, which identifies thresholds of risk. The new Sheffield table, unlike any other method, can be used as screening tool for cholesterol measurement.

Conclusions

The new Sheffield table and modified JBS chart are valid for use in primary care since their diagnostic accuracy is unaffected by approximations in age and blood pressure. It is suggested that practitioners should choose whichever risk assessment tool they are comfortable with and use it.
How many deaths are caused by second hand cigarette smoke?
Authors: Woodward Alistair , Laugesen Murray
Published: July 2002

OBJECTIVES

To estimate the number of deaths attributable to second hand smoke (SHS), to distinguish attributable and potentially avoidable burdens of mortality, and to identify the most important sources of uncertainty in these estimates.

METHOD

A case study approach, using exposure and mortality data for New Zealand.

RESULTS

In New Zealand, deaths caused by past exposures to second hand smoke currently number about 347 per year. On the basis of present exposures, we estimate there will be about 325 potentially avoidable deaths caused by SHS in New Zealand each year in the future. We have explored the effect of varying certain assumptions on which the calculations are based, and suggest a plausible range (174–490 avoidable deaths per year).

CONCLUSION

Attributable risk estimates provide an indication for policy makers and health educators of the magnitude of a health problem; they are not precise predictions. As a cause of death in New Zealand, we estimate that second hand smoke lies between melanoma of the skin (200 deaths per year) and road crashes (about 500 deaths per year).
Coevolutionary patterns in theLinum marginale-Melampsora liniassociation at a continental scale
Authors: Burdon J J , Thrall P H , Lawrence G J
Published: July 2002

Patterns in the distribution of virulence and resistance in the Linum marginale A. Cunn. ex. Planch  Melampsora lini (Ehrenb.) Lev. hostpathogen interaction that is endemic to Australia were examined in a 3500-km pancontinental comparison. Pathogen isolates derived from Western Australia were virulent on a much greater proportion of hosts from Western Australia than they were on a broad range of L. marginale lines collected throughout eastern Australia. In contrast, the physical isolation of Western Australia had no discernible effect on the distribution of the mean resistance of host lines. Within eastern Australia, isolates collected from Tasmania (isolated by 100 km of sea), southern New South Wales, and South Australia showed varying levels of response in terms of their virulence on host lines originating from the same or other eastern subregions. Finally, across the entire distribution of the pathogen, there was a significant effect of distance such that more distant pathogen isolates were generally less well adapted to host lines than more locally derived ones.Key words: coevolution, pathogen, resistance, rust, speciation, virulence.
Direct-space analysis of the electronic structure of the YBa2Cu3O6and YBa2Cu3O7crystals
Authors: Cargnoni Fausto , Scavini Marco
Published: July 2002

The electronic structure of the YBa2Cu3O6and YBa2Cu3O7crystals is investigated by means of fully periodic-restricted HartreeFock LCAO (linear combination of atomic orbitals) pseudopotential calculations. To give a detailed description of the bonding and atomic properties of the materials studied we selected the quantum theory of atoms in molecules approach, and complementary information is obtained from the analysis of the electron localization function in specific cell regions. The main features of the YBa2Cu3O6and YBa2Cu3O7crystals' electron densities are detailed and compared with available experimental data. Since the superconducting transition requires oxidation of the YBa2Cu3O6crystal, we focused on the electronic rearrangements related to the inclusion of oxygen. CuO planes, probably responsible for the superconducting transition, exhibit peculiar electronic properties.Key words: superconducting cuprates, electron density, ab initio calculations.
A novel metal-chain extension reaction: synthesis of (X)[Os(CO)3(CN-t-Bu)]nMn(CO)5(X = Cl, Br, I;n= 1, 2, 3)
Authors: Jiang Faming , Jenkins Hilary A , Green David F , Yap Glenn PA , Pomeroy Roland K
Published: July 2002

Complexes of formula (X)[Os(CO)3(CN-t-Bu)]nMn(CO)5(X = Cl, Br, I; n = 1, 2, 3) have been prepared by the reaction of Os(CO)4(CN-t-Bu) with Mn(CO)5(X) in hexane at room temperature. The characterization of the complexes included the crystal structures of compounds with X = I, n = 1, 3 and X = Cl, Br, n = 2 (2ClA and 2BrB). The trinuclear products were isolated as two isomers. The major isomer (2XA) has an isocyanide ligand attached to each osmium atom, whereas the minor isomer (2XB) has both of these ligands bound to the terminal Os atom. The structures contain OsnMn chains with unbridged OsMn bonds (range of lengths are 2.870(1)2.9245(8) Å) and for compounds with n = 2 or 3 OsOs bonds (range of lengths are 2.8812(4)2.8928(5) Å). The mechanism of formation is believed to involve replacement of a CO ligand with the 18e-ligand Os(CO)4(CN-t-Bu) at the metal with the coordinated halide, followed by a rearrangement in which the halide ligand migrates to the donor Os atom with concomitant migration in the reverse direction of a carbonyl ligand. The preparation of (OC)4(t-BuNC)OsMn(CO)4(Cl) with an OsMn dative bond is also reported along with the (OC)4(t-BuNC)OsRe(CO)4(X) analogues.Key words: manganeseosmium, rheniumosmium, dinuclear, metal chain, dative metalmetal bond.
Utilisation de vecteurs tournants pour l'optimisation de la formulation de mélanges de solvants
Authors: Alex Serge
Published: July 2002

A new strategy is proposed to optimize the design of solvent blends without using complex mathematical models and (or) graphical representations. All calculations are made with standard electronic programs, such as Excel, Lotus, etc. This approach was developed for the cleaning and degreasing industry, which has to find new recipes of solvent blends on a regular basis. The process relies on a visual analysis of the sum of normalized rotating vectors associated with the chemical composition and the physical properties of the individual components. This approach allows for representation of all parameters on a two-dimensional plot, including information about chemical composition, as well as the physical properties to be optimized. The research of a new mixture of halogenated solvents will be used as an example to illustrate the various steps of this technique. This method is not limited to solvent applications; it also applies to all problems that involve comparisons of physical and chemical properties of blends.Key words: solvents, mixtures, components, optimization, cleaning.
A finite-difference model of temperatures and heat flow within a tree stem
Authors: Potter Brian E , Andresen Jeffrey A
Published: July 2002

The authors present a finite-difference numerical model of heat flow within a horizontal section of a tree stem. Processes included in the model are solar radiative heating, infrared emission and absorption, convective heat exchange between tree surface and the atmosphere, and conduction inside the tree. Input variables include wood density, wood thermal conductivity, wood specific heat, wind speed, air temperature, and insolation. The model produces time series of temperature for grid points inside the tree stem. Based on comparison with observations from two case studies, the model appears capable of reproducing relative timing and amplitude of temperature patterns at the cardinal aspects. Sensitivity tests show that insolation and convection parameters, as well as the physical properties of the tree, can all have a strong influence on model results.
Studies on the angiotensin-converting enzyme and the kinin B2receptor in the rabbit jugular vein: modulation of contractile response to bradykinin
Authors: Gobeil, Jr. Fernand , Hallé Stéphanie , Blais Paul-André , Regoli Domenico
Published: July 2002

The rabbit jugular vein (rbJV) was used as a bioassay system to validate some early and new hypothetical interactions between the angiotensin-converting enzyme (ACE) and the B2receptor, which may be influenced by ACE inhibitors (ACE-I). These involve the potentiation of the contractile effect of bradykinin (BK) and BK analogues, which are inactivated by ACE (e.g., [Hyp3, Tyr(Me8)]-BK (R556)), the prevention of BK-induced B2receptor desensitisation, and the restoration of receptor sensitivity in tissues desensitised with B2receptor agonists. Enzymatic degradation studies performed in vitro and in vivo revealed that BK and R556 are readily degraded by rabbit ACE whereas [Phe8ψ(CH2-NH)Arg9]-BK (R379) is totally resistant. BK, R556, and R379 contracted endothelium-denuded veins with similar potencies (pEC50range 8.108.50). Tissues pretreated with ACE-I showed an increase in pEC50values for BK and R556 but not for R379. ACE-I (captopril, enalaprilat) were unable to prevent B2receptor desensitisation induced by BK (1 µM). ACE-I partially restored B2receptor-mediated contraction in tissues initially exposed to BK but not to R379. These effects were antagonised by HOE 140 (0.1 µM) but were unaffected by AcLys[Dβ-Nal7, Ile8]-desArg9BK (R715) (1 µM) or by Losartan (1 µM). In conclusion, the potentiation of BK and its analogues relates exclusively on prevention of their metabolism, B2receptor desensitisation is not affected by ACE-I, and restoration of tissue responsiveness to BK by ACE-I may be attributed to changes in BK concentrations in the vicinity of the B2receptor.Key words: B2receptor, angiotensin-converting enzyme, inhibitor, BK, jugular vein, rabbit.
GATE RESIZING TO REDUCE POWER CONSUMPTION
Authors: CHENG EDWARD Y. C. , SAHNI SARTAJ
Published: July 2002

We study the problem of resizing gates so as to reduce overall power consumption while satisfying a circuit's timing constraints. Polynomial time algorithms for series-parallel and tree circuits are obtained. Gate resizing with multigate modules is shown to be NP-hard. Algorithms that improve upon those presented by Chen and Sarrafzadeh4 for general circuits are also developed.
UHF FLOWS AND THE FLIP AUTOMORPHISM
Authors: KISHIMOTO A.
Published: July 2002

A UHF algebra is a C*-algebra A of the type [Formula: see text] for some sequence (ni) with ni≥2, where Mn is the algebra of n×n matrices, while a UHF flow α is a flow (or a one-parameter automorphism group) on the UHF algebra A obtained as [Formula: see text], where [Formula: see text] for some [Formula: see text]. This is the simplest kind of flows on the UHF algebra we could think of; yet there seem to have been no attempts to characterize the cocycle conjugacy class of UHF flows so that we might conclude, e.g., that the non-trivial quasi-free flows on the CAR algebra are beyond that class. We give here one attempt, which is still short of what we have desired, using the flip automorphism of A⊗A. Our characterization for a somewhat restricted class of flows (approximately inner and absorbing a universal UHF flow) says that the flow α is cocycle conjugate to a UHF flow if and only if the flip is approximated by the adjoint action of unitaries which are almost invariant under α⊗α. Another tantalizing problem is whether we can conclude that a flow is cocycle conjugate to a UHF flow if it is close to a UHF flow in a suitable sense. We give a solution to this, as a corollary, for the above-mentioned restricted class of flows. We will also discuss several kinds of flows to clarify the situation.
SKYRMIONS, FULLERENES AND RATIONAL MAPS
Authors: BATTYE RICHARD A. , SUTCLIFFE PAUL M.
Published: July 2002

We apply two very different approaches to calculate Skyrmions with baryon number B ≤ 22. The first employs the rational map ansatz, where approximate charge B Skyrmions are constructed from a degree B rational map between Riemann spheres. We use a simulated annealing algorithm to search for the minimal energy rational map of a given degree B. The second involves the numerical solution of the full non-linear time dependent equations of motion, with initial conditions consisting of a number of well separated Skyrmion clusters. In general, we find a good agreement between the two approaches. For B ≥ 7 almost all the solutions are of fullerene type, that is, the baryon density isosurface consists of twelve pentagons and 2B - 14 hexagons arranged in a trivalent polyhedron. There are exceptional cases where this structure is modified, which we discuss in detail. We find that for a given value of B there are often many Skyrmions, with different symmetries, whose energies are very close to the minimal value, some of which we discuss. We present rational maps which are good approximations to these Skyrmions and accurately compute their energy by relaxation using the full non-linear dynamics.
LONG RANGE ORDER IN THE FALICOV-KIMBALL MODEL: EXTENSION OF KENNEDY–LIEB THEOREM
Authors: LEBOWITZ JOEL L. , MACRIS NICOLAS
Published: July 2002

We study the Falicov-Kimball model on Zd, d ≥ 2, in the grand canonical ensemble with chemical potentials μe for the itinerant fermions ("electrons") and μn for the static particles ("nuclei"). There is an on site attraction –2U between electrons and nuclei. Kennedy and Lieb showed that, at the symmetry point μe = μn = –U, at which, for all temperatures the average densities of both electrons and nuclei equal to [Formula: see text], this model exhibits crystalline order for sufficiently low temperatures with the nuclei (and electrons) occupying predominantly the even or odd sublattices. In this paper we extend the results of Kennedy and Lieb to a strip in the (μe, μn) plane, surrounding the symmetry point, whenever U and [Formula: see text] are large (β is the inverse temperature). This means we need not have equal densities of electrons and nuclei as long as they are both close to [Formula: see text].
A DEFORMATION OF THE BIG CELL INSIDE THE GRASSMANNIAN MANIFOLD G(r,n)
Authors: FIORESI R.
Published: July 2002

In this paper we construct a quantum analogue of the big cell inside the grassmannian manifold. Our deformation comes in tandem with a coaction of the upper parabolic subgroup in SLn(k), giving to the big cell the structure of quantum homogeneous space. At the end we give the De Rham complex of the quantum big cell and we define a ring of differential operators acting on the quantum big cell.
IMMERSION ANOMALY OF DIRAC OPERATOR ON SURFACE IN ℝ3
Authors: MATSUTANI SHIGEKI
Published: July 2002

In previous report (J. Phys. A (1997) 30 4019–4029), I showed that the Dirac operator confined in a surface immersed in ℝ3 by means of a mass type potential completely exhibits the surface itself and is identified with that of the generalized Weierstrass equation. In this article, I quantized the Dirac field and calculated the gauge transformation which exhibits the gauge freedom of the parameterization of the surface. Then using the Ward–Takahashi identity, I showed that the expectation value of the action of the Dirac field is expressed by the Willmore functional and area of the surface, or the action of Polyakov's extrinsic string.
ON SOLITON AUTOMORPHISMS IN MASSIVE AND CONFORMAL THEORIES
Authors: MÜGER MICHAEL
Published: July 2002

For massive and conformal quantum field theories in 1+1 dimensions with a global gauge group we consider soliton automorphisms, viz. automorphisms of the quasilocal algebra which act like two different global symmetry transformations on the left and right spacelike complements of a bounded region. We give a unified treatment by providing a necessary and sufficient condition for the existence and Poincaré covariance of soliton automorphisms which is applicable to a large class of theories. In particular, our construction applies to the QFT models with the local Fock property — in which case the latter property is the only input from constructive QFT we need — and to holomorphic conformal field theories. In conformal QFT soliton representations appear as twisted sectors, and in a subsequent paper our results will be used to give a rigorous analysis of the superselection structure of orbifolds of holomorphic theories.
ASYMPTOTIC COMPLETENESS IN QUANTUM IN FIELD THEORY: MASSIVE PAULI–FIERZ HAMILTONIANS
Authors: DEREZIŃSKI J. , GÉRARD C.
Published: July 2002

Spectral and scattering theory of massive Pauli–Fierz Hamiltonians is studied. Asymptotic completeness of these Hamiltonians is shown. The proof consists of three parts. The first is a construction of asymptotic fields and a proof of their Fock property. The second part is a geometric analysis of observables. Its main result is what we call geometric asymptotic completeness. Finally, the last part is a proof of asymptotic completeness itself.
COMBINATORIAL NOVIKOV–MORSE THEORY
Authors: FORMAN ROBIN
Published: July 2002

In [7, 8, 9], we developed a combinatorial Morse theory which can be applied to any CW complex. In [25, 26] Novikov presented a generalization of classical Morse theory in which the Morse function is replaced by a closed 1-forms. In this paper we extend our combinatorial Morse theory to include a combinatorial analog of Novikov's theory. Along the way we introduce the notion of a combinatorial differential form which is well-suited to our work, and which may have other applications.
HIGHER DIMENSIONAL RIEMANN MAPS
Authors: BALOGH ZOLTAN M. , LEUENBERGER CHRISTOPH
Published: July 2002

We consider the notion of Riemann map of Lempert and Semmes. The purpose of this paper is to give an intrinsic and biholomorphically invariant characterization of strictly pseudoconvex domains in Cn which admit a Riemann map. In this sense necessary and sufficient conditions are given for the existence of a Riemann map in terms of Kobayashi discs and the associated Lempert invariants.
LOCAL BOX-COUNTING TO DETERMINE FRACTAL DIMENSION OF HIGH-ORDER CHAOS
Authors: OSAKA MOTOHISA , ITO NOBUYASU
Published: July 2002

To determine the attractor dimension of chaotic dynamics, the box-counting method has the difficulty in getting accurate estimates because the boxes are not weighted by their relative probabilities. We present a new method to minimize this difficulty. The local box-counting method can be quite effective in determining the attractor dimension of high-order chaos as well as low-order chaos.
DIPLOID VERSUS HAPLOID ORGANISMS
Authors: TICONA ARMANDO , DE OLIVEIRA PAULO MURILO C.
Published: July 2002

Using a bit string model, we show that asexual reproduction for diploids is more efficient than for haploids: it improves genetic material producing new individuals with less deleterious mutations. We also see that in a system where competition is present, diploids dominate, even though we consider some dominant loci.
AN EXAMPLE RELEVANT TO THE KRETSCHMANN–EINSTEIN DEBATE
Authors: SORKIN RAFAEL D.
Published: July 2002

We cast the flat space theory of a scalar field in generally covariant form by introducing an auxiliary field λ. The resulting theory is couched in terms of an action integral S, and all the fields (the scalar, the space–time metric, and λ) are dynamical in the sense of being varied freely in S. Conservation of energy–momentum emerges as a formal consequence of diffeomorphism invariance, in close analogy with the situation in ordinary general relativity.
NEUTRINO MASSES FROM NON-MINIMAL GRAVITATIONAL INTERACTIONS OF MASSIVE NEUTRAL FERMIONS
Authors: GUPTA ABHINAV , MAHAJAN NAMIT , MUKHERJEE AMITABHA
Published: July 2002

A new mechanism is proposed for generating neutrino masses radiatively through a non-minimal coupling to gravity of fermionic bilinears involving massive neutral fermions. Such coupling terms can arise in theories where the gravity sector is augmented by a scalar field. They necessarily violate the principle of equivalence, but such violations are not ruled out by the present experiments. It is shown that the proposed mechanism is realized most convincingly in theories of the Randall–Sundrum type, where gravity couples strongly in the TeV range. The mechanism has the potential of solving both the solar and atmospheric neutrino problems. The smallness of neutrino masses in this scenario is due to the fact that the interaction of the massive neutral fermions arises entirely from higher-dimensional operators in the effective Lagrangian.