Interaction effects of multiple pool fires

What are the effects of flame behavior of a number of fires burning in close proximity to one another? The results of measurements of burning rates, heat feedback, flame height, and flame trailing are reported for fires involving liquid pools.     

What are the symptoms of varicose veins? Edinburgh vein study cross sectional population survey

OBJECTIVE: To define the relations between age, sex, lower limb symptoms, and the presence of trunk varicose veins on clinical examination. DESIGN: Cross sectional population study. SETTING: 12 general practices with catchment areas geographically and socioeconomically distributed throughout Edinburgh. PARTICIPANTS: An age stratified random sample of 1566 people (699 men and 867 women) aged 18-64 selected from the computerised age-sex registers of participating practices. MAIN OUTCOME MEASURES: Self administered questionnaire on the presence of lower limb symptoms and physical examination to determine the presence and severity of varicose veins. RESULTS: Women were significantly more likely than men to report lower limb symptoms such as heaviness or tension, swelling, aching, restless legs, cramps, and itching. The prevalence of symptoms tended to increase with age in both sexes. In men, only itching was significantly related to the presence and severity of trunk varices (linear test for trend, P=0.011). In women there was a significant relation between trunk varices and the symptoms of heaviness or tension (P相似文献   

Accelerated Fretting Wear Tests for Contacts Exposed to Atmosphere

Engineering components can be subjected to normal and/or rotational fretting wear with contacts that are intermittently exposed to the atmosphere. Exposure to the environment may lead to the alteration at the contact due to the changing role of third body particles such as hard oxides which can result in abrasion. The abrasion due to hard oxide particles differs for the closed contact and intermittently opened contact. In the former scenario, the oxides are compacted into tribo-film, while in the latter case they remain loose, leading to bigger role of abrasion. Standard fretting test setup employed to estimate the fretting wear characteristic operates with a constant load such that the contact remains closed between the counter surfaces and does not simulate the opening and closing of the contacts as observed in certain applications. The forceful interruptions to the experiments to simulate open and close condition of the contact require considerable amount of time and effort. In this paper, an accelerated test procedure is proposed and investigated to capture the effect of intermittent opening of the contact without stopping the experiments. A test rig is designed to simulate the opening and closing conditions, and tests were performed with abrasive diamond-like particles. Friction and wear results are compared with those of intermittently contact opening conditions along with operating wear mechanisms. Scanning electron microscope analysis showed that the wear mechanism observed in the case of fretting with intermittent opening of contact is similar to that of fretting with diamond-like abrasives at the contact.     

Multiple anterograde tracing, combining Phaseolus vulgaris leucoagglutinin with rhodamine- and biotin-conjugated dextran amine

The simultaneous use of different neuroanatomical anterograde tracers provides a potentially powerful method to study the convergence of afferent systems in a particular brain area. However, a simple routine procedure to apply multiple anterograde tracers in conjunction with their simultaneous visualization is still missing. We report an easy and straightforward application of three sensitive anterograde tracers: Phaseolus vulgaris leucoagglutinin (PHA-L), rhodamine-conjugated dextran amine (RDA) and biotin-conjugated dextran amine (BDA). These tracers can be visualized simultaneously and permanently through a triple-staining procedure with nickel-enhanced diaminobenzidine (DAB-Ni), DAB and 1-naphthol/Azur B as chromogens. Our test model comprised the projections from the nucleus reuniens thalami and entorhinal cortex. Both projection systems show a high degree of overlap in their terminal fields in the hippocampus. Two tracers were injected in the left and right entorhinal cortex, respectively; a third tracer was injected in the nucleus reuniens. This combination of injections provided a good opportunity to compare the three tracers in one and the same animal. PHA-L, RDA and BDA, injected in either of the injection sites, turned out to be equally sensitive and revealed the morphology of the involved projection systems in great detail. The triple-staining protocol yielded an excellent, simultaneous detectability of the three tracers with a remarkably low background level. Thus, the combination of the anterograde tracers PHA-L, RDA and BDA, in conjunction with the triple-staining procedure, offers a very attractive approach for neuroanatomical research.     

Diuretics: role of sodium balance

Diuretics are commonly prescribed for a wide variety of clinical problems, including hypertension, extracellular volume excess, and disorders of calcium metabolism. Although natriuresis with altered sodium balance is not always the therapeutic goal, this feature of the diuretics is essential for optimal results, irrespective of the clinical problem.     

Surgical release of elbow-capsular contracture in pediatric patients

Nine pediatric patients with elbow-capsular contractures were treated by surgical release. Six patients had sustained prior trauma and three patients had medical conditions leading to capsular contracture. A lateral approach was used to release the anterior and posterior capsules, as well as to remove sites of bony impingement. All patients were treated with postoperative range of motion and splinting, with six patients receiving a continuous brachial plexus block to facilitate therapy. Average loss of extension improved from 47 to 15 degrees, mean angle of flexion from 102 to 124 degrees, and total arc of motion increased from 55 to 108 degrees at an average of 17 months after surgery. Complications included wound infection and catheter-site erythema.     

Increased use of mammography among Hispanic women: baseline results from the NCI Cooperative Group on Cancer Prevention in Hispanic Communities

BACKGROUND: The Healthy People 2000 report set the objective of increasing the percentage of women 40 or older who had ever received a mammogram and clinical breast examination to 80% by the year 2000. The report used a baseline of 36% for all American women and 20% for Hispanic women. The purpose of this study was to compare baseline estimates with data obtained in five Hispanic communities. METHODS: Common survey measures were administered in five studies participating in a National Cancer Institute Cooperative agreement. The surveys evaluated history of mammography in five Hispanic communities in the southwestern Unites States. RESULTS: Across the five communities, the rates of mammography use were significantly higher than the national baseline. Among women 40-49 years of age, 55% had completed mammography (95% confidence interval [CI] = 52%, 57%). Among women 50 years of age or older, 64% had received a mammogram (95% CI = 62%, 66%). Older women (above age 50) were significantly more likely to have completed the test than younger women (younger than age 50), and mammography was obtained less often among women who were uninsured and those who had lower levels of acculturation. CONCLUSIONS: We conclude that the rate of mammography use among Hispanic women has increased significantly over the last few years and that we are on track to reach the goal of 80% mammography compliance for Hispanic women 40 years and older by the year 2000.     

Segregation analysis of the testis-determining autosomal trait, Tda, that differs between the C57Bl/6J and DBA/2J mouse strains suggests a multigenic threshold model

The testis-determining autosomal trait (Tda) of the mouse was uncovered when the Y chromosome of the poschiavinus variety of Mus musculus domesticus was introduced into the C57BL/6J laboratory strain background. Testis development is normal in the F1 generation but, in the backcross and subsequent crosses to C57BL/6J females, XY individuals with the poschiavinus Y chromosome expressed bilateral ovaries or various combinations of an ovotestis with a contralateral ovary or testis or bilateral ovotestes and few had testes bilaterally. In other strain backgrounds, such as DBA/2J, XY individuals with the poschiavinus Y chromosome always expressed normal testes bilaterally. The first breeding analysis of this difference in the interaction of strain background with the poschiavinus Y chromosome suggested that the Tda trait was due to a single gene, but attempts to map it failed. We constructed two strains of C57BL/6J and DBA/2J that are consomic for the poschiavinus Y chromosome in order to conduct a segregation analysis of the Tda trait. In the C57BL/6J.Y-POS consomic strain, liability to express incomplete testis development is normally distributed and thresholds in development specify the probability of different classes of ovary, ovotestis, and testis combinations. Testis development is complete in the DBA/2J.Y-POS consomic strain. We demonstrated previously that the Tda trait of C57BL/6J is recessive to that of DBA/2J and the segregating first backcross generation of embryos rejected the single-gene model. We have extended our analysis to a F2 generation of embryos that also rejects a single-gene model. We also report a test mating analysis of the first backcross generation. It was initiated to provide an independent assessment of the single-gene model, but the analysis of the distribution of test mating results suggests that the difference in the Tda trait between C57BL/6J and DBA/2J may be due to a small number of loci, possibly four or five, and that the phenotypic effect between loci may be additive.     

Reduction of renal uptake of monoclonal antibody fragments by amino acid infusion

The renal uptake of radiolabeled antibody fragments and peptides presents a problem in radioimmunodetection and therapy, compromising lesion sensitivity, especially with intracellularly-retained isotopes. Previously, we showed that cationic amino acids and their derivatives are capable of significantly reducing kidney uptake in animals. We report our initial clinical results of successful renal uptake reduction in five patients who underwent cancer radioimmunodetection with 99mTc-anti-CEA Fab' fragments. METHODS: The patients were infused with two liters of a commercially-available nutritive amino acid solution (containing approximately 2.25 g/liter lysine-glutamate and 2.50 g/liter arginine), whereas 75 control patients received the same volume of saline (quantification of organ and tumor kinetics from conjugate whole-body views by ROI technique). RESULTS: The renal uptake in the amino acid group was significantly lower (p<0.05) than in the control group (11.1 +/- 2.0% injected dose versus 17.7 +/- 7.0% injected dose at 24 hr postinjection), whereas the uptake of all other organs remained unaffected. Gel filtration chromatography of the urine taken from amino-acid-treated patients showed that a significantly higher amount of excreted activity was bound to intact Fab' (53% of excreted activity) in contrast to only less than 10% in the control group. CONCLUSION: The renal uptake of monoclonal antibody fragments in patients can be reduced significantly by amino acid infusion, even at considerably lower doses than those that were safe and effective in animals. As was found in animals, the mechanism seems to rely on an inhibition of the re-absorption of tubularly-filtered proteins by the proximal tubule cells. These results encourage further clinical trials to lower the renal uptake experienced in radioimmunodetection, as well as in therapeutic trials with antibody fragments and peptides.     

Right and left ventricular geometry and myocyte contractile processes with dilated cardiomyopathy: myocyte growth and beta-adrenergic responsiveness

OBJECTIVES: Comparison of the effects of supraventricular tachycardia-induced dilated cardiomyopathy on left and right ventricular isolated myocyte geometry and function. BACKGROUND: Chronic ventricular tachycardia and supraventricular tachycardia cause left ventricular dilation and dysfunction in humans. However, it is unknown whether supraventricular tachycardia-induced dilated cardiomyopathy is a homogenous process for both the left and right ventricles. METHODS: Dilated cardiomyopathy was induced by rapid atrial pacing (240 beats/min, 3 weeks) in 5 pigs. Five age- and weight-matched pigs served as controls. Ventricular mass was measured, myocyte dimensions were obtained, and isolated right and left ventricular myocyte contractile performance was evaluated at baseline and after beta-adrenergic receptor stimulation. RESULTS: With the development of dilated cardiomyopathy, there was no change in left ventricular mass. In contrast, right ventricular mass was increased, as was right ventricular myocyte cross-sectional area. In the control group, baseline right ventricular myocyte contractile function was increased compared to left ventricular myocytes. beta-adrenergic receptor stimulation increased myocyte contractile function in both left and right ventricular myocytes. With supraventricular tachycardia-induced cardiomyopathy, both left and right ventricular myocyte contractile function and beta-adrenergic responsiveness were reduced. CONCLUSIONS: This study demonstrated differences in left and right ventricular myocyte growth with supraventricular tachycardia-induced dilated cardiomyopathy and this differential growth response was associated with changes in contractile performance. Thus, in this model of cardiomyopathic disease, left and right ventricular growth and changes in contractile performance are not a homogenous process.