bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Nitro-Substituted 4-Oxo-4H-pyrimido[2,1-b]benzothiazole-3-carboxylic Acids and Their Spectral Characteristics
Authors: Bartovič Alexander , Ilavský Dušan , Šimo Ondrej , Zalibera Lubomír , Belicová Anna , Seman Milan
Published: July 2002

The Gould-Jacobs reaction of all position isomeric 2-aminonitrobenzothiazoles II with diethyl ethoxy- methylenemalonate has been studied. The structure of substitution (IV) and cyclization (VI) products and of the corresponding acids (VIII) was confirmed by elemental analysis, IR, UV, 1H and 13C NMR spectra. Analogous derivatives III, V and VII, derived from the unsubstituted 2-aminobenzothiazole I, were used as standards in interpretation of the spectra. The synthesized derivatives I - VIII were tested for antimicrobial activity.
Measurement and Calculation of the Raman Optical Activity of α-Pinene and trans-Pinane
Authors: Bouř Petr , Baumruk Vladimír , Hanzlíková Jana
Published: July 2002

Raman scattering and Raman optical activity (ROA) spectra of α-pinene and trans-pinane were measured for both enantiomers. The experiment was performed on a newly built, fully computer-controlled backscattering incident circular polarization ROA instrument. High-quality spectra were obtained and interpreted on the basis of ab initio quantum chemical calculations. Excellent agreement between the calculated and observed spectra was observed in the mid IR region. An approximate distributed origin gauge model for calculation of the polarization tensors was proposed. The shapes of ROA spectra calculated with this model are similar to those obtained with conventional, computationally more demanding ROA computations.
Addition of Azoimide to Unsaturated Ketones in the Steroid Series. Synthesis of N-(17β-Hydroxy-3-oxo-5α-androstan-15β-yl)succinamoic Acid and Its Evaluation as Hapten for Dihydrotestosterone Immunoanalysis
Authors: Černý Ivan , Pouzar Vladimír , Lapčík Oldřich , Hampl Richard
Published: July 2002

Addition of azoimide to 17-oxoandrosta-5,15-dien-3β-yl acetate or 17-oxo-5α-androst-15-en-3β-yl acetate gave in both cases corresponding 15β-azido derivatives. 15β-Azido-17-oxo-5α-androstan-3β-yl acetate was selectively reduced to 17β-hydroxy derivative and protected as methoxymethyl ether. Subsequent reduction of azide group and condensation with methyl hydrogen succinate gave a protected succinylamino derivative. Deacetylation and oxidation then led to dihydrotestosterone (DHT) series. Successive removal of protecting groups gave N-(17β-hydroxy-3-oxo-5α-androstan-15β-yl)succinamoic acid, an experimental hapten for DHT. Its conjugate with bovine serum albumin was used for immunization of rabbits and corresponding antisera were evaluated in RIA using [3H]-DHT as a tracer. The results are comparable with standard kits based on antisera generated using DHT derivatives with connecting bridge in position 7.
Vanadyl Phosphate and Its Intercalation Reactions. A Review
Authors: Kalousová Jaroslava , Votinský Jiří , Beneš Ludvík , Melánová Klára , Zima Vítězslav
Published: July 2002

The structure of the layered αI-VOPO4, VOPO4·2H2O, and their intercalation reactions are discussed. These reactions are divided into two groups. The first includes intercalation reactions of molecular guests which proceed as acid-base processes between the host layered lattice (Lewis acid) and a donor atom of the guest (base). Interaction of water molecules, alcohols, amines, carboxylic acids and their derivatives, heterocyclic N- and S-donors, and complex compounds with vanadyl phosphates is discussed. Vanadyl phosphate, in particular vanadyl phosphate dihydrate can also undergo the second type of the reactions which involves the reduction of a fraction of vanadium(V) atoms to vanadium(IV) with concomitant intercalation of alkylammonium, hydronium or mono- and divalent metal cations to counterbalance the induced negative layer charge. A review with 76 references.
Electrochemical Investigations of Alkaline Cleavage of Lignin Under Mild Conditions
Authors: Zuman Petr , Rupp Elinore B.
Published: July 2002

At pH 8-12 and 25 °C, 10-20% of lignin undergoes cleavage producing soluble species. In suspensions of lignin it is possible to follow the concentration changes of hydroxybenzaldehydes and α,β-unsaturated carbonyl compounds. These species can be determined by the recording of polarographic current-voltage curves directly in the suspensions, where the presence of suspended and colloidal particles does not interfere with the function of the DME. The base-catalyzed cleavage follows first-order kinetics. The pH dependence indicates that the rate determining step is not a nucleophilic attack by OH-, rather the rate determining step is preceded by a rapidly established acid-base equilibrium. The cleavage of natural lignins obtained enzymatically follows a pattern similar to that of rot wood lignins and surprisingly also to that of kraft lignins. The patterns of cleavages are different from those of lignosulfonates, Klason, periodate and expansion lignin. The three dimensional (tertiary) structure of lignin seems to play a role in its reactivity.
Physiological and anthropometric determinants of sport climbing performance
Authors: Mermier Christine M , Janot Jeffrey M , Parker Daryl L , Swan Jacob G
Published: July 2002

Objective—To identify the physiological and anthropometric determinants of sport climbing performance.

Methods—Forty four climbers (24 men, 20 women) of various skill levels (self reported rating 5.6–5.13c on the Yosemite decimal scale) and years of experience (0.10–44 years) served as subjects. They climbed two routes on separate days to assess climbing performance. The routes (11 and 30 m in distance) were set on two artificial climbing walls and were designed to become progressively more difficult from start to finish. Performance was scored according to the system used in sport climbing competitions where each successive handhold increases by one in point value. Results from each route were combined for a total climbing performance score. Measured variables for each subject included anthropometric (height, weight, leg length, arm span, % body fat), demographic (self reported climbing rating, years of climbing experience, weekly hours of training), and physiological (knee and shoulder extension, knee flexion, grip, and finger pincer strength, bent arm hang, grip endurance, hip and shoulder flexibility, and upper and lower body anaerobic power). These variables were combined into components using a principal components analysis procedure. These components were then used in a simultaneous multiple regression procedure to determine which components best explain the variance in sport rock climbing performance.

Results—The principal components analysis procedure extracted three components. These were labelled training, anthropometric, and flexibility on the basis of the measured variables that were the most influential in forming each component. The results of the multiple regression procedure indicated that the training component uniquely explained 58.9% of the total variance in climbing performance. The anthropometric and flexibility components explained 0.3% and 1.8% of the total variance in climbing performance respectively.

Conclusions—The variance in climbing performance can be explained by a component consisting of trainable variables. More importantly, the findings do not support the belief that a climber must necessarily possess specific anthropometric characteristics to excel in sport rock climbing.
Circumferential resection margin involvement: an independent predictor of survival following surgery for oesophageal cancer
Authors: Dexter S P L , Sue-Ling H , McMahon M J , Quirke P , Mapstone N , Martin I G
Published: July 2002

BACKGROUND

For rectal carcinoma, the presence of tumour within 1 mm of the circumferential margin is an important independent prognostic factor for both local recurrence and survival. Similar prospective data have not been reported for oesophageal carcinoma and we wished to ascertain the prognostic importance of this variable following potentially curative resection for oesophageal carcinoma.

AIM

To prospectively assess the impact of circumferential margin involvement (tumour within 1 mm) following potentially curative resection for oesophageal carcinoma.

PATIENTS AND METHODS

In a prospective study, resection specimens of 135 patients treated with potentially curative oesophageal resection alone were studied for the presence of tumour within 1 mm of the circumferential margin (margin positive), using inked margins and cross sectional slicing of the specimen. All tumours were also staged using the 1987 UICC TNM classification. Patients were followed for a mean of 19 months, and overall and cancer specific survival analysed.

RESULTS

The finding of tumour cells within 1 mm of the circumferential margin (CRM+) was a significant and independent predictor of survival following potentially curative oesophageal resection. Overall, 64 (47%) patients were CRM+. Median survival in this group was 21 months compared with 39 months in the CRM− group (p=0.015). The impact of CRM status on survival was only seen in patients with a low nodal metastatic burden (<25% nodes positive). The odds ratio for the risk of dying from oesophageal cancer was 2.08 when the CRM was involved (p=0.013).

CONCLUSIONS

The presence of tumour within 1 mm of the circumferential margin following potentially curative resection for oesophageal carcinoma is an important independent prognostic variable and should be reported routinely.
What price dissection? Dissection literally dissected
Authors: Francis Nathan R , Lewis Wayne
Published: July 2002

Hamlet: Has this fellow no feelings of his business, that he sings at grave-making?

Horatio: Custom hath made it in him a property of easiness.

(Hamlet Act V, scene i)1

Hamlet is appalled by the gravedigger's insensitivity towards death and corpses. Horatio explains that the gravedigger is so accustomed to such things that he no longer shares Hamlet's seriousness. We contend that human dissection may make in medical students and doctors the “property of easiness” in dealing with death and the human body, and that this may have negative consequences for medics and patients. It is perhaps worth emphasising at the outset what this essay is NOT about. We do not wish to call into question the value of dissection in medical education; to charge dissection with being an inefficient or ineffective means of teaching and learning human anatomy is not our intent. Instead, we explore, through the medium of literature, experiences of dissection, and what kind of student and doctor may be encouraged or produced by the dissection room; what price might be paid for a practical, first-hand experience of human anatomy.
Two patients with occupational asthma who returned to work with dust respirators: Table 1
Authors: Obase Yasushi , Shimoda Terufumi , Mitsuta Kazuko , Matsuse Hiroto , Kohno Shigeru
Published: July 2002

OBJECTIVES

To assess the efficacy of dust respirators in preventing asthma attacks in patients with occupational asthma (asthma induced by buckwheat flour or wheat flour).

METHODS

The effect of the work environment was examined in two patients with occupational asthma with and without the use of a commercially available mask or a dust respirator. Pulmonary function tests were performed immediately before and after work and at 1 hourly intervals for 14 hours after returning to the hospital.

RESULTS

In patient 1, environmental exposure resulted in no symptoms during and immediately after work, but coughing, wheezing, and dyspnoea developed after 6 hours. Peak expiratory flow rate (PEFR) decreased by 44% 7 hours after leaving the work environment, showing only a positive late asthmatic reaction (LAR). In patient 2, environmental exposure resulted in coughing and wheezing 10 minutes after initiation during bread making, and PEFR decreased by 39%. After 7 hours, PEFR decreased by 34%. The environmental provocation tests in both patients were repeated after wearing a commercial respirator. This resulted in a complete suppression of LAR in patient 1 and of immediate asthmatic reaction (IAR) and LAR in patient 2.

CONCLUSIONS

Two patients with asthma induced by buckwheat flour or wheat flour in whom asthmatic attacks could be prevented with a dust respirator are reported. Dust respirators are effective in preventing asthma attacks induced by buckwheat flour and wheat flour.
Non-Hodgkin's lymphoma among electric utility workers in Ontario: the evaluation of alternate indices of exposure to 60 Hz electric and magnetic fields
Authors: Villeneuve Paul J , Agnew David A , Miller Anthony B , Corey Paul N
Published: July 2002

OBJECTIVES

To examine associations between non-Hodgkin's lymphoma (NHL) and exposures to 60 Hz magnetic and electric fields in electric utility workers with a series of indices that capture a variety of aspects of field strength.

METHODS

The study population consisted of 51 cases of NHL and 203 individually matched controls identified from within a cohort of male electric utility workers in Ontario. Odds ratios were calculated for several exposure indices with conditional logistic regression models. Aspects of exposure to electric and magnetic fields that were modelled included: the percentage of time spent above selected threshold field intensities, mean transitions in field strength, SD, and the arithmetic and geometric mean field intensities.

RESULTS

For the most part, there was a lack of an association between exposure indices of magnetic fields and the incidence of NHL. Subjects in the upper tertile of percentage of time spent above electric field intensities of 10 and 40 V/m had odds ratios of 3.05 (95% confidence interval (95% CI) 1.07 to 8.80) and 3.57 (1.30 to 9.80), respectively, when compared with those in the lowest tertile. Moreover, the percentages of time spent above these electric field thresholds were significant predictors of case status over and above the association explained by duration of employment and the arithmetic or geometric mean exposure.

CONCLUSIONS

These data suggest that exposures above electric field threshold intensities of 10 and 40 V/m are important predictors of NHL. Consequently, the findings support the hypothesis that electric fields may play a promoting part in the aetiology of this cancer. Further occupational studies that include assessment of exposure to electric fields and measures of field strength above similar threshold cut off points are needed to confirm these findings.
Exposure biomarkers and risk from gluing and heating of polyurethane: a cross sectional study of respiratory symptoms
Authors: Littorin Margareta , Rylander Lars , Skarping Gunnar , Dalene Marianne , Welinder Hans , Strömberg Ulf , Skerfving Staffan
Published: July 2002

OBJECTIVES

To define the relation between exposure to polyurethane (PUR) glue, biomarkers of exposure and effect, and work related symptoms that occur at least once a week.

METHODS

In a cross sectional study, 152 workers and 14 clerks in a factory with exposure to sprayed and heated PUR glue containing 4,4′-diphenylmethane (MDI) or 1,6-hexamethylene (HDI) di-isocyanate were examined with gas chromatography-mass spectrometry (GC-MS) for metabolites of MDI in plasma (P-MDX) and urine (U-MDX), 2,4- and 2,6-toluene di-isocyanate (TDI; P-TDX, U-TDX) and HDI in plasma and urine, specific serum IgG (S-IgG-MDI, S-IgG-HDI, and S-IgG-TDI, respectively) and IgE (S-IgE-MDI). Work related symptoms of the eyes and airways (nose or lower airways, or both), and lung function were also evaluated.

RESULTS

P-MDX was detected in 65% of the workers, U-TDX in 47%, HDX in none. Three per cent were positive for S-IgE-MDI, 33% for S-IgG-MDI, 32% for S-IgG-TDI, and 12% for S-IgG-HDI. A few clerks had metabolites, and some had antibodies. Most metabolites and immunoglobulins were slightly correlated—for example, P-MDXvS-IgG-MDI: rs=0.21. Workers who heated glue had increased P-MDX (odds ratio (OR)=12 for a value above the median) and S-IgG-MDI (OR=3.7), sprayers P-2,4-TDX (OR=6.2) and P-2,6-TDX (OR=16). Twenty six per cent of the workers had work related symptoms of the airways, 21% from the nose, 11% from the lower airways. Spraying of glue increased the risk of work related symptoms and slightly decreased lung function. U-MDX was associated with work related symptoms from the airways (OR=3.7) and P-2,6-TDX with work related symptoms from the lower airways (OR=6.6). S-IgG-MDI was related to work related symptoms from the airways (OR=2.6).

CONCLUSIONS

There were relations between exposures to sprayed and heated PUR glue based on MDI and HDI, concentrations of metabolites of MDI and TDI in plasma and urine, specific IgG serum antibodies against MDI, TDI, and HDI, and work related symptoms.
109Cd Kxray fluorescence measurements of tibial lead content in young adults exposed to lead in early childhood
Authors: McNeill Fiona E , Stokes Lynette , Brito José A A , Chettle David R , Kaye Wendy E
Published: July 2002

OBJECTIVES

Tibia lead measurements were performed in a population of 19–29 year old people who had been highly exposed to lead in childhood to find whether lead had persisted in the bone matrix until adulthood.

METHODS

109Cd Kxray fluorescence was used to measure the tibia lead concentrations of 262 exposed subjects and 268 age and sex matched controls. Questionnaire data allowed a years of residence index to be calculated for exposed subjects. A cumulative blood lead index was calculated from the time weighted integration of available data of blood lead.

RESULTS

The mean (SEM) difference between exposed and control men was 4.51 (0.35) μg Pb/g bone mineral, and between exposed and control women was 3.94 (0.61) μg Pb/g bone mineral. Grouped mean bone lead concentrations of exposed subjects were predicted best by age. When exposed and control subjects' data were combined, grouped mean bone lead concentrations were predicted best by cumulative blood lead index. The years of residence index was neither a good predictor of bone lead concentrations for exposed subjects nor for exposed and control subjects combined. Finally, exposed subjects had increased current blood lead concentrations that correlated significantly with bone lead values.

CONCLUSION

Bone lead concentrations of exposed subjects were significantly increased compared with those of control subjects. Lead from exposure in early childhood had persisted in the bone matrix until adulthood. Exposed subjects had increased blood lead concentrations compared with controls. Some of this exposure could be related to ongoing exposure. However, some of the increase in blood lead concentration in adult exposed subjects seemed to be a result of endogenous exposure from increased bone lead stores. The endogenous exposure relation found for men was consistent with reported data, but the relation found for women was significantly lower. Further research is needed to find whether the observed differences are due to sex, or pregnancy and lactation.
Evaluation of a postgraduate educational programme for occupational physicians on work rehabilitation guidelines for patients with low back pain: Table 1
Authors: Smits P B A , Verbeek J H A M , van Dijk F J H , Metz J C M , ten Cate Th J
Published: July 2002

OBJECTIVES

The postgraduate educational programme for occupational physicians on guidelines for work rehabilitation of patients with low back pain was evaluated as to what extent did knowledge of the guidelines increase, and did the workers improve their performance at work.

METHODS

An experimental group (n=25) attended an educational programme and a reference group did so (n=20) 6 months later. Knowledge and performance were assessed for both groups, before and after education of the experimental group. Knowledge was assessed for the reference group after education.

RESULTS

Knowledge increased significantly more in the experimental group. The reference group's score increased further after education. The experimental group's adjusted gain score for performance indicators was significantly positive. Analysis of covariance also showed a significant effect for the experimental group for increased performance score.

CONCLUSIONS

The educational programme improved the quality of care because knowledge and performance of occupational physicians improved and complied better with practice guidelines.
Acute respiratory effects of particles: mass or number?
Authors: Osunsanya T , Prescott G , Seaton A
Published: July 2002

OBJECTIVES

To determine whether associations might be found, in patients with chronic airflow obstruction, between symptoms, peak flow rate (PEF), and particle mass and numbers, and to assess which measure was most closely associated with changes in health. Epidemiological studies have shown associations between particulate air pollution and cardiovascular and respiratory disease, and it has been proposed that these may be mediated by particles of nm size (ultrafine).

METHODS

Relations were investigated between symptom scores, PEF, and bronchodilator use in 44 patients aged ⩾50 years with chronic obstructive pulmonary disease, and daily measurements of both mass of ambient particles of aerodynamic diameter less than 10 μm (PM10) and numbers of ultrafine particles (<100 nm), allowing for meteorological variables. Symptom scores, bronchodilator use, and PEF were recorded daily for 3 months. Counts of ultrafine particles were made by the TSI model 3934 scanning mobility particle sizer (SMPS) and PM10measurements by the tapered element oscillating microbalance (TEOM).

RESULTS

Ultrafine particle counts indoors and outdoors were significantly correlated, those indoors being about half of those outdoors. No associations were found between actual PEF and PM10or ultrafine particles. However, there was a 19% increase in the rate of 10% decrements in daytime PEF with increases in PM10from 10 to 20 μg/m3which was of borderline significance (p=0.05). A change in PM10from 10 to 20 μg/m3was significantly associated with a 14% increase in the rate of high scores of shortness of breath (p=0.003). A similar change in PM10as a moving average of the same day and 2 previous days was associated with a 31% increase in the rate of high scores for cough (p=0.02). Cough symptoms were also associated with lower temperatures (p=0.02). Higher use of medicines was also associated with higher PM10, but the increases were very small in clinical terms.

CONCLUSIONS

Evidence was not found to support the hypothesis that the component of particulate pollution responsible for effects on respiratory symptoms or function resides in the fraction below 100 nm diameter. The consistent associations between symptoms and PM10suggest that a contribution of the coarser fraction should not be dismissed. Further studies will be needed before the conclusions of this specific project may be generalised.
Response of finger circulation to energy equivalent combinations of magnitude and duration of vibration
Authors: Bovenzi M , Lindsell C J , Griffin M J
Published: July 2002

OBJECTIVES

To investigate the acute response of finger circulation to vibration with different combinations of magnitude and duration but with the same “energy equivalent” acceleration magnitude according to current standards for hand transmitted vibration.

METHODS

Finger skin temperature (FST) and finger blood flow (FBF) were measured in the middle fingers of both hands of 10 healthy men who had not used hand held vibrating tools regularly. With a static load of 10 N, the right hand was exposed to 125 Hz vibration with the following unweighted root mean square (rms) acceleration magnitudes and durations of exposure: 44 m/s2for 30 minutes; 62 m/s2for 15 minutes; 88 m/s2for 7.5 minutes; 125 m/s2for 3.75 minutes; and 176 m/s2for 1.88 minutes. These vibration exposures produce the same 8 hour energy equivalent frequency weighted acceleration magnitude (∼1.4 m/s2rms) according to international standard ISO 5349 (1986). Finger circulation was measured in both the right (vibrated) and the left (non-vibrated) middle fingers before application of the vibration, and at fixed intervals during exposure to vibration and during a 45 minute recovery period.

RESULTS

The FST did not change during exposure to vibration, whereas vibration with any combination of acceleration magnitude and duration produced significant percentage reductions in the FBF of the vibrated finger compared with the FBF before exposure (from −40.1% (95% confidence interval (95% CI) −24.3% to −57.2%) to −61.4% (95% CI −45.0% to −77.8%). The reduction in FBF during vibration was stronger in the vibrated finger than in the non-vibrated finger. Across the five experimental conditions, the various vibration stimuli caused a similar degree of vasoconstriction in the vibrated finger during exposure to vibration. There was a progressive decrease in the FBF of both fingers after the end of exposure to vibration with acceleration magnitudes of 44 m/s2for 30 minutes and 62 m/s2for 15 minutes. Significant vasoconstrictor after effects were not found in either finger after exposure to any of the other vibration stimuli with greater acceleration magnitudes for shorter durations.

CONCLUSIONS

For the range of vibration magnitudes investigated (44 to 176 m/s2rms unweighted; 5.5 to 22 m/s2rms when frequency weighted according to ISO 5349), the vasoconstriction during exposure to 125 Hz vibration was independent of vibration magnitude. The after effect of vibration was different for stimuli with the same energy equivalent acceleration, with greater effects after longer durations of exposure. The energy equivalent acceleration therefore failed to predict the acute effects of vibration both during and after exposure to vibration. Both central and local vasoregulatory mechanisms are likely to be involved in the response of finger circulation to acute exposures to 125 Hz vibration.
Psychological factors and visual fatigue in working with video display terminals
Authors: Mocci F , Serra A , Corrias G A
Published: July 2002

OBJECTIVES

To examine the part played by psychological factors in complaints about visual health reported by banking officers who work at video display terminals (VDTs).

METHODS

Out of a population of 385 bank workers, a group of 212 subjects without organic visual disturbances (as determined by opthalmological examination) who share a work environment and job duties was selected. Three questionnaires were administered to these subjects: (a) the NIOSH job stress questionnaire; (b) a questionnaire investigating subjective discomfort related to environmental and lighting conditions of the workplace; (c) a questionnaire on the existence of oculovisual disturbances. Correlation and multiple regression analyses were performed to examine for the presence of predictors of asthenopia.

RESULTS

Social support, group conflict, self esteem, work satisfaction, and underuse of skills were found to be predictors of visual complaints; social support played a part also as a moderating factor in the stress and strain model; this model accounted for 30% of the variance. Subjective environmental factors, although in some cases significantly correlated with asthenopia, were not found to be strong predictors of the symptoms.

CONCLUSIONS

Some part of the complaints about visual health reported by VDT workers are likely indirect expressions of psychological discomfort related to working conditions.
An increased standardised mortality ratio for liver cancer among polyvinyl chloride workers in Taiwan
Authors: Wong R-H , Chen P-C , Du C-L , Wang J-D , Cheng T-J
Published: July 2002

Aims:To determine the standardised mortality ratio (SMR) corresponding to different causes of death in workers from polyvinyl chloride polymerisation factories in Taiwan.

Methods:Retrospective cohort study of workers from six polyvinyl chloride polymerisation factories in Taiwan. A total of 3293 male workers who had been employed for at least one year during the period 1 January 1950 to 31 December 1992, and were alive on 1 January 1985 were included for analysis. Using data acquired from Taiwan's National Mortality Registry, it was found that 144 of these workers died during the period 1985–97. The follow up rate was 99% with a total number of person-years at risk of 40 557.

Results:SMR for all causes of death was 0.78, indicating a possible “healthy worker” effect. The SMR for liver cancer decreased with increasing age of first exposure to vinyl chloride monomer. This association was more prominent for workers who were first employed in the industry prior to 1970 (SMR 4.82). Medical records indicated that most liver cancers in this study were hepatocellular carcinoma.

Conclusions:Polyvinyl chloride workers may experience a higher risk of developing liver cancer, particularly hepatocelluar carcinoma.
Specialist follow up of patients before end stage renal failure and its relationship to survival on dialysis
Authors: Stoves J , Bartlett C N , Newstead C G
Published: July 2002

The high mortality rate of patients with end stage renal failure (ESRF) treated by dialysis is determined principally by irreversible factors such as age and comorbidity. In this single centre retrospective study of all 1260 ESRF patients who started dialysis between 1980 and 1999 it has been demonstrated that a short duration of specialist predialysis follow up is associated with a worse long term outcome on dialysis.

Kaplan-Meier survival curves were plotted according to duration of predialysis follow up (group A, ⩽ 90 days; group B >90 days), censoring for first transplant, and compared using a log rank test. Differences between groups were examined using an unpaired t test. Cox regression analysis was performed to examine the influence of selected variables on survival.

Group A had the worst mortality (survival proportions of 87%, 74%, and 31% in A and 94%, 87%, and 55% in B at four months, one year, and five years respectively, p<0.001). The increased risk of death was seen principally during the first few months of dialysis. ESRF associated with systemic disease was more prevalent in A. There were small but significant differences in predialysis clinical data, including age and serum albumin (p<0.001). Fewer patients in A were suitable for transplant listing (p<0.01). In the regression analysis, age, diabetes, predialysis serum albumin, suitability for transplant work-up and listing (“transplantability”), and the interval between referral and dialysis were significant predictors of survival.

In summary, this study strengthens the previously reported association between late referral of ESRF patients and subsequent poor survival on dialysis. This important message is relevant to all potential referring physicians. Key pointsThe high mortality rate of patients with ESRF treated by dialysis is determined principally by irreversible factors such as age and comorbidity.We have demonstrated in a single centre retrospective study of more than 1200 patients with ESRF that a short duration of specialist predialysis follow up is associated with an increased risk of death on dialysis, principally during the first few months of treatment.Delays in the referral to renal specialist services of patients with advanced chronic renal failure should be minimised.
Primary care referral protocol for carpal tunnel syndrome
Authors: Hayward A C , Bradley M J , Burke F D
Published: July 2002

Carpal tunnel syndrome is an extremely common upper limb nerve compression syndrome, widely distributed in the community. There are a variety of treatment options which may be applied to the syndrome, depending on the severity of symptoms. Some options are available in a primary care setting, others require secondary referral. This paper is a detailed review of the available literature and provides a protocol that could be used to assist in the referral of patients from primary care.
An unusual case of infective endocarditis
Authors: Houghton T , Kaye G C , Meigh R E
Published: July 2002

A rare case of Corynebacterium striatum endocarditis on a bioprosthetic aortic valve replacement, treated medically, is reported. The presentation was subacute, and initially endocarditis screening was negative. Because of the failure of symptoms to settle further screening was performed which confirmed the organism in several sets of blood cultures. This emphasises the importance of persistent screening for endocarditis if the history raises any suspicion of this potentially serious infection, especially in the presence of prosthetic valves.
Accounting for local physiological adaptation in bioenergetic models: testing hypotheses for growth rate evolution by virtual transplant experiments
Authors: Munch Stephan B , Conover D O
Published: July 2002

We constructed bioenergetic models for locally adapted populations of Atlantic silversides, Menidia menidia, from different latitudes (Nova Scotia and South Carolina) to determine how genetic variation in growth physiology affects model parameters and predicted growth and to test two hypotheses on the evolution of countergradient variation in growth rate. Model parameters were estimated simultaneously for each population through a penalized likelihood approach incorporating laboratory measurements of metabolism, specific dynamic action, consumption, and growth. The resulting population-specific parameters differed by an average of 28%. The models were validated by successful (R2 > 0.9) prediction of growth in independent experiments under natural light and temperature conditions and by predicting growth in the field (R2 > 0.95). We then performed virtual reciprocal transplant simulations to test the alternative hypotheses that growth rate along a latitudinal gradient evolves in response to temperature or resource availability. Predictions for each transplanted population deviated significantly from observed growth for each native population, demonstrating the importance of accounting for interpopulation variation in model parameters. Our results indicate that the latitudinal cline in growth rate cannot be explained solely by thermal adaptation but may have arisen owing to the combined effects of temperature and food availability.
Studies of the ceruloplasmin-lactoferrin complex
Authors: Pulina Maria O , Zakharova Elena T , Sokolov Alexei V , Shavlovski Mikhail M , Bass Mikhail G , Solovyov Kirill V , Kokryakov Vladimir N , Vasilyev Vadim B
Published: July 2002

We have previously shown that iron-containing human lactoferrin (LF) purified from breast milk is able to form both in vitro and in vivo a complex with ceruloplasmin (CP), the copper-containing protein of human plasma. Here we present evidence that the CPLF complex is dissociated by high concentrations of NaCl, CaCl2, or EDTA, or by decreasing the pH to 4.7. In addition, DNA, bacterial lipopolysaccharide, and heparin can displace CP from its complex with LF. Antibodies to either of the two proteins also cause dissociation of the complex.Key words: lactoferrin, ceruloplasmin, ferroxidase.
Remote sensing based assessment of hazards from glacier lake outbursts: a case study in the Swiss Alps
Authors: Huggel Christian , Kääb Andreas , Haeberli Wilfried , Teysseire Philippe , Paul Frank
Published: July 2002

Glacier lakes are a common phenomenon in high mountain areas. Outbursts from glacier lakes have repeatedly caused the loss of human lives as well as severe damage to local infrastructure. In several high mountain ranges around the world, a grave uncertainty about the hazard potential of glacier lakes still exists, especially with respect to the effects of accelerating rates of glacier retreat as a consequence of atmospheric warming. Area-wide detection and modeling of glacier lake hazard potentials is, therefore, a major challenge. In this study, an approach integrating three scale levels allows for the progressive focus on critical glacier lakes. Remote sensing methods for application in glacier lake hazard assessment are presented, and include channel indexing, data fusion, and change detection. Each method matches the requirements of a certain scale level. For estimating potential disaster amplitudes, assessments must be made of maximum discharge and runout distance of outbursts floods and debris flows. Existing empirical relations are evaluated and complementary ones as derived from available data are proposed. Tests with observations from a recent outburst event from a moraine-dammed lake in the Swiss Alps show the basic applicability of the proposed techniques and the usefulness of empirical relations for first hazard assessments. In particular, the observed runout distance of the debris flow resulting from the outburst does not exceed the empirically estimated maximum runout distance. A list of decision criteria and related remote sensing techniques are discussed in conclusion. Such a list is an essential tool for evaluating the hazard potential of a lake. A systematic application of remote sensing based methods for glacier lake hazard assessment is recommended.Key words: glacier lake outburst, hazard potential, remote sensing, empirical parameters.
THE POWER OF DUALITY — EXACT RESULTS IN 4D SUSY FIELD THEORY
Authors: SEIBERG N.
Published: July 2002

Recently the vacuum structure of a large class of four-dimensional (supersymmetric) quantum field theories was determined exactly. These theories exhibit a wide range of interesting new physical phenomena. One of the main new insights is the role of "electric–magnetic duality." In its simplest form it describes the long distance behavior of some strongly coupled, and hence complicated, "electric theories" in terms of weakly coupled "magnetic theories." This understanding sheds new light on confinement and the Higgs mechanism and uncovers new phases of four-dimensional gauge theories. We review these developments and speculate on the outlook.
SUPERSTRIPES
Authors: BIANCONI A.
Published: July 2002

A superconducting superlattice of quantum stripes with a particular shape that gives the amplification of the critical temperature is called "superstripes". This superlattice is characterized by: a) the metallic stripe width L of the order of the de Broglie wavelength of electrons at the Fermi level, L ~λ F , and b) the hopping of pairs between the stripes larger than the hopping of single electrons. "Superstripes" can be realized artificially to get new room temperature superconductors (RTS). This particular mesoscopic heterostructure at the atomic limit has been found as a self organized network of charges, in a short time and space scale, in doped cuprate perovskites near the micro-strain quantum critical point for "superstripes" formation.
EFFECTS OF INTERACTION FOR THE QUANTUM DIFFUSION IN COUPLED CHAINS
Authors: HATSUGAI Y. , SUGI A.
Published: July 2002

Effects of electron–electron interaction for the quantum diffusion is investigated numerically in quasi one-dimensional systems (coupled chains) with a few particles. We have observed localization even with the interaction after sufficient time evolution. The localization length ξ increases by the interactions in the weak coupling region. Also significant enhancement of the localization length ξ is observed by the increase of the chain numbers.
EXACTLY SOLVABLE MODEL OF PROTEIN FOLDING: RUBIK'S MAGIC SNAKE MODEL
Authors: IGUCHI KAZUMOTO
Published: July 2002

I study the conceptual framework of protein folding considering an exactly solvable model — the Rubik's magic snake model. I discuss the mathematical representation of the model, the model Levinthal paradox, the non-unique compact folded structure, the function of the chain, the ground state energy, the commensurability between the folded structure and the potential sequence, the relationship between the unique ground state and broken symmetry in this model and the dual model and the inflation of the magic snake chain, respectively.
CHEMICAL AND PHYSICAL PROPERTIES OF TANTALUM POWDER
Authors: PURUSHOTHAM Y. , BALAJI T. , KUMAR ARBIND , GOVINDAIAH R. , SHARMA M. K. , SETHI V. C. , PRAKASH T. L.
Published: July 2002

The present work is intended to produce capacitor grade Tantalum powder by sodium reduction of potassium tantalum fluoride prepared from an indigenous ore source. The powder has been characterized for its chemical and physical properties, and compared with the commercially available powders. It is found that indigenous powder has higher impurity levels which could, however, be reduced to acceptance limits. The average particle size is within the prescribed limits.
A SIMPLE RENORMALIZATION SCHEME IN RANDOM SURFACE THEORY
Authors: BOTELHO LUIZ L. C.
Published: July 2002

We propose a simple Analytical Renormalization Scheme for the self-avoiding interaction of a Random Surface with the origin.
THE GIANT VOLUMETRIC MAGNETOSTRICTION OF FERROMAGNETIC COMPOSITES WITH ELASTOMER MATRIX
Authors: BEDNAREK S.
Published: July 2002

The results of investigation of volumetric magnetostriction of a ferromagnetic composite consisting of silicon steel particles dispersed in an elastomer matrix and its relaxation are presented. The composite consisted of silicon steel particles of 0.15–0.20 mm in size, which were dispersed in a polymerized silicone. The filling factor of the composite by these particles amounted to 0.4, 0.6 or 0.8. The investigation was carried out by means of the pycnometric method in a magnetic field with the induction of 0–8 T produced by Bitter's magnet. It was found that according to the filling factor and the induction of the applied magnetic field, relative changes in the sample volume amounted to (0.37–112.8) × 10-4 and the relaxation time of the volumetric magnetostriction was 2.12–85.8 s.
UNIVERSAL CNN CELLS
Authors: DOGARU RADU , CHUA LEON O.
Published: July 2002

A cellular neural/nonlinear network (CNN) [Chua, 1998] is a biologically inspired system where computation emerges from a collection of simple nonlinear locally coupled cells. This paper reviews our recent research results beginning from the standard uncoupled CNN cell which can realize only linearly separable local Boolean functions, to a generalized universal CNN cell capable of realizing arbitrary Boolean functions. The key element in this evolutionary process is the replacement of the linear discriminant (offset) function w(σ)=σ in the "standard" CNN cell in [Chua, 1998] by a piecewise-linear function defined in terms of only absolute value functions. As in the case of the standard CNN cells, the excitation σ evaluates the correlation between a given input vector u formed by the outputs of the neighboring cells, and a template vector b, which is interpreted in this paper as an orientation vector. Using the theory of canonical piecewise-linear functions [Chua & Kang, 1977], the discriminant function [Formula: see text] is found to guarantee universality and its parameters can be easily determined. In this case, the number of additional parameters and absolute value functions m is bounded by m<2n-1, where n is the number of all inputs (n=9 for a 3×3 template). An even more compact representation where m<n-1 is also presented which is based on a special form of a piecewise-linear function; namely, a multi-nested discriminant: w (σ) =s (zm +| zm -1 +⋯ | z1 +| z0 +σ |||). Using this formula, the "benchmark" Parity function with an arbitrary number of inputs n is found to have an analytical solution with a complexity of only m =O ( log 2 (n)).
LIE–TROTTER FORMULA AND POISSON DYNAMICS
Authors: PUTA MIRCEA
Published: July 2002

We construct via the Lie–Trotter formula some explicit Poisson integrators for the Maxwell–Bloch equations from laser-matter dynamics, the Euler equations of the free rigid body and the equations of the rigid body with a spinning rotor.
THE CENTER PROBLEM FOR DISCONTINUOUS LIÉNARD DIFFERENTIAL EQUATION
Authors: COLL B. , PROHENS R. , GASULL A.
Published: July 2002

We prove that the Lyapunov constants for differential equations given by a vector field with a line of discontinuities are quasi-homogeneous polynomials. This property is strongly used to derive the general expression of the Lyapunov constants for two families of discontinuous Liénard differential equations, modulus some unknown coefficients. In one of the families these coefficients are determined and the center problem is solved. In the other family the center problem is just solved by assuming that the coefficients which appear in these expressions are nonzero. This assumption on the coefficients is supported by their computation (analytical and numerical) for several cases.
PSEUDOVARIETY JOINS INVOLVING ${\mathscr J}$ -TRIVIAL SEMIGROUPS
Authors: ALMEIDA JORGE , AZEVEDO ASSIS , ZEITOUN MARC
Published: July 2002

J. Rhodes asked during the Chico Conference in 1986 for the calculation of joins of semigroup pseudovarieties. This paper proves that the join J∨H of the pseudovariety J of [Formula: see text]-trivial semigroups and of any 2-strongly decidable pseudovariety V of of completely regular semigroups is decidable. This problem was proposed by the first author for V=G, the pseudovariety of finite groups.
MULTIPLY-ADD OPTIMIZED FFT KERNELS
Authors: KARNER HERBERT , AUER MARTIN , UEBERHUBER CHRISTOPH W.
Published: July 2002

Modern computer architecture provides a special instruction — the fused multiply-add (FMA) instruction — to perform both a multiplication and an addition operation at the same time. In this paper newly developed radix-2, radix-3, and radix-5 FFT kernels that efficiently take advantage of this powerful instruction are presented. If a processor is provided with FMA instructions, the radix-2 FFT algorithm introduced has the lowest complexity of all Cooley–Tukey radix-2 algorithms. All floating-point operations are executed as FMA instructions. Compared to conventional radix-3 and radix-5 kernels, the new radix-3 and radix-5 kernels greatly improve the utilization of FMA instructions, which results in a significant reduction in complexity. In general, the advantages of the FFT algorithms presented in this paper are their low arithmetic complexity, their high efficiency, and their striking simplicity. Numerical experiments show that FFT programs using the new kernels clearly outperform even the best conventional FFT routines.
DISSIPATIVE DISCRETIZATION METHODS FOR APPROXIMATIONS TO THE BOLTZMANN EQUATION
Authors: RINGHOFER CHRISTIAN
Published: July 2002

This paper deals with the spatial discretization of partial differential equations arising from Galerkin approximations to the Boltzmann equation, which preserves the entropy properties of the original collision operator. A general condition on finite difference methods is derived, which guarantees that the discrete system satisfies the appropriate equivalent of the entropy condition. As an application of this concept, entropy producing difference methods for the hydrodynamic model equations and for spherical harmonics expansions are presented.
ON THE ASYMPTOTIC EXPANSIONS OF NUMERICAL SOLUTIONS TO SECOND ORDER DIFFERENTIAL EQUATIONS WITH A REGULAR SINGULAR POINT
Authors: WEISS RICHARD , de HOOG FRANK R. , ANDERSSEN ROBERT S.
Published: July 2002

When difference schemes with uniformly spaced gridpoints are applied to second order ordinary differential equations with a regular singular point, it is often the case that the resulting numerical approximation does not have a uniform asymptotic expansion. As a consequence, postprocessing, such as h2-extrapolation is not an option. This paper examines the cause of this phenomenon and finds that the existence of such expansions requires the discretization of the boundary conditions at the singular point to be compatible with the discretization of the differential equation. In addition, it is shown how an understanding of the need for compatible discretization can assist in the construction of schemes for several classes of equations that arise when symmetry is used to reduce partial differential equations to ordinary differential equations with a regular singular point.