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51.
52.
VA Tutel'ian 《Canadian Metallurgical Quarterly》1996,(6):16-19
Studies covered nutrition of immigrants in Far North and revealed considerable disturbances and shortage in vitamin supply. The authors necessitate general efforts to maintain balanced nutrition with consideration of Far Northern conditions. 相似文献
53.
OBJECTIVES: Public policy has treated drinking and boating as though it were analogous to drinking and driving. Accordingly, recent Federal and state laws to prevent drinking and boating have focused solely on alcohol use by the boat operator. This study was designed to determine boaters' knowledge about the epidemiology of boating fatalities and how boaters perceive the risks of drinking and boating. METHODS: In the summer of 1995, the authors conducted a survey by mail of a random sample of 600 owners of boats registered in Massachusetts. RESULTS: Survey results indicated that boaters believe passengers can safely drink more than operators. Respondents also thought that people on boats at rest can safely drink more than people on boats underway. CONCLUSIONS: The results of this study could be helpful in designing future boating safety campaigns by identifying gaps in knowledge about about the risks of drinking and boating for both operators and passengers. 相似文献
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The process of the transfer of the Ti-plasmid vector pGV3850 with the plasmid pBR322 inserted into the T-DNA region from Agrobacterium tumefaciens to a non-plasmid strain of Escherichia coli was studied. The transferred Ti-plasmid was found to be exposed to deletions and formed a wide range of derivatives with a size ranging from 3-4 kb to 50 kb, maintained in E. coli due to ColE1-replicon. The Ti-plasmid is also inserted into the chromosome of the recipient bacterium with at least a 100-fold lower frequency than the formation of deletional derivatives. It was shown that the induction of vir genes controlling the transfer of T-DNA into plants has no appreciable effect on the efficiency of obtaining transconjugates in mating with E. coli. The deletion of the genetic material of megaplasmids with the inserted functional site OriV ColE1, as a result of the conjugative transfer from cells of different bacteria to the cells of E. coli, was proposed for molecular cloning. 相似文献
56.
VA Kraevski? 《Canadian Metallurgical Quarterly》1998,32(6):1050-1055
BACKGROUND: Vasoactive intestinal polypeptide (VIP)-secreting tumors of the pancreas represent a rare subtype of pancreatic islet cell tumors with an estimated incidence of 0.2 to 0.5 per million per year. We provide data on a relatively large series of patients with VIP-secreting tumors and review current literature regarding this specific entity. METHODS: A retrospective review was performed of all patients with VIP-secreting tumors of the pancreas treated from 1977 to 1992 at our institution. Presenting signs, symptoms, mode of diagnosis, extent of disease, surgical resectability, tumor size, treatments, hormone levels, and survival were assessed. RESULTS: Eighteen patients were identified, 9 male and 9 female. Ages ranged from 23 to 74 years (mean 51 years). Secretory diarrhea was the most common symptom, occurring in 16 of 18 patients (89%). The most common tumor location was the tail of the pancreas (9 patients). Fourteen patients (78%) had liver metastasis at diagnosis. Curative resections were attempted in only 5 patients (28%). The mean survival was 3.6 years with the longest disease-free survival being 15 years and longest overall survival 15 years. CONCLUSIONS: VIP-secreting tumors are extremely rare entities and usually metastatic at the time of diagnosis. Despite advanced disease, these patients can have extended survival. 相似文献
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IB Shchepotin VL Valetsky VA Chorny M Shabahang RJ Nauta RR Buras SR Evans 《Canadian Metallurgical Quarterly》1997,33(9):1413-1418
Medical consequences of many nuclear accidents on humans are well studied, but the results pertaining to gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident have not been analysed. In this study, the outcome of the surgical treatment of 68 gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident was compared with that of 117 consecutive gastric cancer patients from uncontaminated areas of the Ukraine. Patients in the study group was significantly younger than that of the control group. Comparative analysis showed the same frequency of regional metastases (65.7% versus 71.1%, P > 0.05), but a smaller number of distant metastases (23.8% versus 38.1%, P < 0.05) in the study group. 41.2% of patients in the study group underwent total gastrectomy compared to 19.6% of patients in the control group (P = 0.002). Postoperative complications developed in 13.2% of patients in the study group, while postoperative mortality in the study group was 7.3% compared to 1.7% in the control group. A significant decrease in CD16 cells was noted in patients from the study group following the operative procedure. Young age, invasive tumours with smaller number of distant metastases, frequent necessity for total gastrectomy and combined operations with adjacent organs, a higher level of postoperative morbidity and mortality and low levels of natural killer cells (CD16+) with a tendency to decrease after surgery are characteristic of patients with carcinoma of the stomach affected by the Chernobyl accident. 相似文献
59.
Investigation of children's understanding of the cognitive verb forget has shown that young children do not consider the role of prior knowledge when using this verb. Thus, someone may be said to have forgotten a fact despite not ever having previously known it. However, forget can also be used to refer to a failure to recall a prior intention. Three experiments examined the role of prior intention as well as prior knowledge in the comprehension of forget by 160 young children aged four to eight years. The results showed that children initially have two interpretations of forget: as an unfulfilled desire rather than a failure to recall a prior intention, and as a state of not knowing rather than a failure to recall prior knowledge. Explanations for the late comprehension of forget are discussed in terms of representation of knowledge and intention, processing capacity and exposure to pragmatic usages. 相似文献
60.
Binding of exogenous actinomycin D (AMD) by washed mycelium of streptomycetes i.e. variants of Streptomyces chrysomallus producing and not producing actinomycins and Streptomyces lividans not synthesizing the antibiotics was studied. Dependence of the bound quantity of AMD on its concentration, incubation time and temperature, energy source availability, influence of respiration inhibitors and the membranotropic antibiotic gramicidin S was shown. The intracellularly localized portion of the bound AMD likely penetrated to the cells by diffusion and was strongly bound presumably to DNA in the AMD sensitive S.lividans and to the specific intracellular actinomycin-binding proteins in the AMD resistant variants of S.chrysomallus. The ratio of AMD strongly bound by the mycelium and AMD easily washed with physiological solution and probably localized on the surface was determined. The ratio depended on sensitivity of the culture to AMD and for the variants of S.chrysomallus on the age of the culture and its ability to synthesize actinomycins. 相似文献