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131.
E Homsi E Pires de Oliveira Dias JF Figueiredo JA Gontijo 《Canadian Metallurgical Quarterly》1998,6(6):551-556
Recent primary prevention trials demonstrated that cardiovascular morbidity and mortality benefits are not accompanied by adverse effects on overall mortality and morbidity in cohorts representing plasma cholesterol concentrations observed in the bulk of coronary artery disease. During the past year, further analyses of the West of Scotland Coronary Prevention Study have indicated that benefit requires a 25% reduction of LDL cholesterol and that such treatment is not very expensive when focussed on selected high-risk individuals. The Air Force/Texas Coronary Artery Prevention Study indicated that benefit is seen in individuals with even lower plasma lipid concentration. Although current treatment with lifestyle and lipid modifying drug management is successful in primary prevention, the unpredictable nature of coronary artery disease and the cost of drugs mitigate against direct application of drug management in persons with relatively low risk, but selective treatment should be undertaken in very high-risk settings. Future studies need to examine more specific at risk cohorts, test better targeted lipoprotein modification, test more risk factors and also examine whether changes in vascular function or markers of inflammation will predict a better outcome. 相似文献
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Generalized Fresnel's reflectance formulas provide the basis for this ray tracing method, which simulates the natural phenomenon of interference color. A visualization of Newton's rings demonstrates its accuracy 相似文献
134.
AV Thillainayagam S Carnaby JA Dias ML Clark MJ Farthing 《Canadian Metallurgical Quarterly》1993,34(7):920-925
Clinical trials suggest that including naturally occurring complex carbohydrate in oral rehydration solutions (ORS) in place of glucose increases water absorption and reduces stool volume during acute diarrhoea. The mechanisms for this greater clinical efficacy has not been established. This study examined the ability of two hypotonic rice based ORS, RS-ORS (137 mOsm/kg) and RP-ORS (143 mOsm/kg), and HYPO-ORS (240 mOsm/kg) a glucose equivalent ORS, to effect water absorption by in vivo perfusion of normal and secreting rat small intestine. The results were compared with those for two widely used conventional hypertonic ORS, WHO-ORS (331 mOsm/kg) and UK-ORS (310 mOsm/kg). In the normal intestine, water absorption was similar from WHO-ORS (87.4 (45.1-124.6) microliters/min/g; median and interquartile range) and UK-ORS (57.6 (41.5-87)) but less than from the hypotonic solutions (p < 0.02); water absorption from RS-ORS (181.8 (168.5-193.8)) and RP-ORS (195.7 (179.3-207.9)) was similar but less than from HYPO-ORS (241.3 (230.6-279.7); p < 0.005). In the secreting intestine, all ORS reversed net secretion of fluid to net absorption; the hypotonic solutions, HYPO-ORS (105.2 (95.2-111)), RS-ORS (127.7 (118.3-169.4)) and RP-ORS (133.7 (122.1-174.5)), produced more water absorption (p < 0.005) than the hypertonic solutions WHO-ORS (47.1 (29-75.9)) and UK-ORS (24.9 (18.4-29.4)). The rice based ions promoted most water absorption in secreting intestine (p < 0.007). These data indicate that low osmolality is of primary importance in mediating the increased water absorption from cereal based ORS. 相似文献
135.
BC Sang L Shi P Dias L Liu J Wei ZX Wang CR Monell F Behm S Gruenwald 《Canadian Metallurgical Quarterly》1997,89(8):2909-2914
Nonrandom chromosomal abnormalities are found in most human malignancies, particularly leukemias and lymphomas. A characteristic t(1;19) (q23;p13.3) chromosomal translocation is detected in 5% of childhood acute lymphoblastic leukemia (ALL) cases. This translocation results in the formation of a fusion gene, which leads to the expression of an oncogenic E2A/pbx1 protein. Breakpoints in the E2A gene almost invariably occur within a single intron, and the identical portion of PBX1 is joined consistently to exon 13 of E2A in fusion mRNA. In this article, we report the development of monoclonal antibodies against E2A/pbx1 fusion protein using a specific peptide that corresponds to the junction region of the protein. The obtained antibodies recognize specifically the chimeric E2A/pbx1 fusion protein and lack cross-reactivities with E2A and pbx1. Immunohistochemical staining and flow cytometric studies show that these antibodies can distinguish t(1;19)-positive from t(1;19)-negative leukemic cells. These results indicate that the obtained E2A/pbx1-specific monoclonal antibodies might prove to be valuable diagnostic reagents and important tools for elucidating the mechanisms involved in oncogenesis and progression of t(1;19)-positive childhood ALL. 相似文献
136.
A Dalsgaard HF Mortensen K M?lbak F Dias O Serichantalergs P Echeverria 《Canadian Metallurgical Quarterly》1996,34(5):1189-1192
In the present study, 19 strains of Vibrio cholerae O1 biotype El Tor isolated during outbreaks of cholera in Guinea-Bissau in 1987, 1994, and 1995 were characterized to investigate a possible epidemiological relationship among the isolates. On the basis of ribotyping with the restriction enzyme BglI, 5 strains isolated in 1987 showed two closely related ribotypes, while 14 strains isolated in 1994 and 1995 showed the same ribotype that was distinct from the ribotypes of strains isolated in 1987. Southern blot hybridization of BglI-digested genomic DNA with a cholera toxin probe demonstrated that the strains isolated in 1987 showed an identical cholera toxin genotype, whereas O1 strains isolated in 1994 and 1995 showed the same genotype that was distinct from the genotype of strains isolated in 1987. These results were supported by the results of antibiotic susceptibility testing, in which strains isolated in 1987 showed resistance to polymyxin B only, while each of the strains from 1994 and 1995 showed resistance to polymyxin B, trimethoprim-sulfamethoxazole, and the vibriostatic agent O/129. Although our results are based on a limited number of V. cholerae O1 strains, they suggest that the epidemic in Guinea-Bissau in 1994 and 1995 was due to the introduction of a new strain to the country. 相似文献
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140.
Ana B. Dias Natlia T. Correia Joaquim J. Moura-Ramos Anabela C. Fernandes 《Polymer International》1994,33(3):293-302
The dipolar relaxation mechanisms in poly(vinyl acetate) have been studied in detail using the technique of thermally stimulated currents. The papers published in the literature about this subject are very contradictory, particularly with respect to the assignment of the observed discharges to the corresponding motions at the molecular level. This work aims at clarifying these problems. We detected and characterised three different relaxation mechanisms: (1) a low temperature one (around ?140°C) which was attributed to local internal rotations in the acetate side-groups; (2) a relaxation whose maximum occurs at 42°C, which corresponds to the glass transition relaxation, and shows a compensation behaviour; (3) an upper glass transition relaxation whose maximum appears at 87°C and was attributed to a liquid-liquid transition. These assignments have been made on the basis of the analysis of the behaviour of the samples when submitted to different thermal and electrical treatments. 相似文献