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The requirements on an object-oriented DBMS for management of information in a large, complex enterprise are presented. These requirements aid in the achievement of an environment characterized by data sharing, open architectures, application and data portability, and assurance of data integrity. They were defined from the point of view of a user of the DBMS; therefore they describe the expected functionality of the DBMS and do not specify the method of implementation to achieve this functionality. They encompass requirements on the data model, query and data manipulation languages, the system architecure, interfaces to the system, change management, and transaction management. 相似文献
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A central sleep apnea is the absence of respiratory effect, and, thus, the absence of airflow during sleep. Central hypopnea, a related disorder, is also discussed. The sensory component of central sleep apnea; defects involving the integrative and executive neurons; non-neurologic causes of central sleep apneas, including chronic obstructive pulmonary disease and congestive heart failure; diagnosis; treatment; and other topics are reviewed in detail. 相似文献
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The miswak chewing stick is an oral hygiene device used by the majority of people in Arab Gulf countries. Despite its widespread use, few studies demonstrated its benefits or applications as an alternative and convenient means for cleansing the teeth. This paper will examine the unique properties of the miswak chewing stick and its proper use. 相似文献
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BE Volos IuM Vasil'ev LV Masliaeva IA Snegurskaia 《Canadian Metallurgical Quarterly》1994,(3-4):92-95
Studied in the course of one-stage epidemiologic survey of 1191 individuals were the threshold of gustatory sensitivity to table salt and nycterine natriuresis, relation of these indices to dietary habits, some risk factors for cardiovascular disorders and clinical parameters. Differing relations were established between gustatory sensitivity to table salt and natriuresis and age and gender of the examinees, the level of blood pressure, aggravated heredity in respect of arterial hypertension, smoking and alcohol abuse, this enabling one to embark upon a differential approach to dietetic correction of salt consumption. 相似文献
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The role of MHC class II in the presentation of Heligmosomoides polygyrus antigens has been investigated, using a number of T cell hybridomas produced in A and E positive and negative mice. By using fixed and irradiated antigen presenting cells (APC), further evidence has emerged, to support earlier data, that there can be differential processing requirements during the presentation of H. polygyrus antigens by A and E molecules. In concordance with these earlier observations, this work provides further evidence than individual T cells can respond to antigen when presented by more than one MHC molecule. Previously, this evidence has been restricted to individual MHC molecules of the same haplotype, but these data show that H. polygyrus produces antigens which can be presented by both syngeneic and allogeneic MHC molecules. These antigens do not appear to be synonymous with the previously described H. polygyrus superantigen, as presentation is restricted to specific MHC haplotypes. It is proposed that H. polygyrus may produce these antigenic molecules as part of its strategy to manipulate the host immune system. 相似文献
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Records of 60 patients with primary salivary gland tumors were retrospectively analyzed. Most were European Jews, 60% were males, and the average age was 57 years. The parotid gland was the most frequent site of origin (76%). The main presenting symptom was painless swelling. Pain or facial palsy were rare and associated with poor prognoses. The most common types were mucoepidermoid, adenocystic, adenocarcinoma and malignant, mixed carcinomas (in descending order of frequency). Squamous cell carcinoma was the most prevalent histologic type. Most patients presented at an advanced stage. Treatment was mainly surgical and postoperative radiotherapy was given to those with advanced disease. Most recurrences occurred within 3 years of initial treatment. Actuarial 10-year survival for all patients was 40%. Superior survival rates were achieved in women, probably due to less aggressive malignancies. Low grade mucoepidermoid carcinoma had a favorable prognosis, whereas anaplastic carcinoma had the worst. Other significant prognostic factors included stage and grade of disease. 相似文献
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