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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
3.
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
4.
KL Hopkins PK Dickson TI Ball RR Ricketts PA O'Shea CR Abramowsky 《Canadian Metallurgical Quarterly》1997,32(10):1476-1479
Fetus-in-fetu is an unusual condition in which a vertebrate fetus is enclosed within the abdomen of another fetus. These occurrences are usually benign. This report describes an instance of malignant recurrence after resection of a fetus-in-fetu. 相似文献
5.
JA McCrohon WA Walters JT Robinson RJ McCredie L Turner MR Adams DJ Handelsman DS Celermajer 《Canadian Metallurgical Quarterly》1997,29(7):1432-1436
OBJECTIVES: We sought to assess whether high dose estrogen treatment is associated with enhanced arterial reactivity in genetic males. BACKGROUND: Although estrogens have been shown to enhance arterial reactivity in women, and are thereby thought to confer cardiovascular benefit, the vascular effects of long-term estrogen therapy in genetic males is unknown. METHODS: We studied the arterial physiology of 30 genetic males--15 male to female transsexuals receiving long-term high dose estrogen therapy and 15 healthy male control subjects matched for age, smoking history and vessel size. Using external vascular ultrasound, brachial artery diameter was measured at rest, after flow increase (causing endothelium-dependent dilation [EDD]) and after nitroglycerin (GTN), an endothelium-independent dilator. Blood pressure, cholesterol and testosterone levels were also measured in each subject. RESULTS: Total testosterone and free testosterone index levels were lower in the transsexuals compared with the control subjects (p < 0.001). In contrast, EDD was significantly higher in the transsexuals than in the control males (mean [+/-SD] 7.1 +/- 3.1% vs. 3.2 +/- 2.8%, p = 0.001), as was the GTN response (21.2 +/- 6.7% vs. 14.6 +/- 3.3%, p = 0.002). Total and high density lipoprotein cholesterol, blood pressure levels and baseline vessel size were similar in the two groups. On multivariate analysis, enhanced EDD was associated independently with estrogen therapy (p = 0.02) and with low total cholesterol (p = 0.04). An enhanced GTN response was also significantly associated with estrogen therapy (p = 0.03). CONCLUSIONS: Long-term treatment with high dose estrogens is associated with enhanced arterial reactivity in genetic males, which may be due to the effects of estrogen excess or androgen deprivation, or both. 相似文献
6.
The past year has seen significant advances in our understanding of the mechanism of RNA movement between the nucleus and the cytoplasm. The emerging view is that proteins bind to and escort RNAs to their proper subcellular location. The discovery of peptide signals that target nuclear export and the identification of novel protein mediators of RNA export are examples of significant recent discoveries. 相似文献
7.
JP Heiner SS Kohles PA Manley R Vanderby MD Markel 《Canadian Metallurgical Quarterly》1997,(341):233-240
In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft. 相似文献
8.
BACKGROUND: To describe abortion utilization in the Canton of Vaud (Switzerland) and to identify desirable changes in the data collection system to improve the epidemiologic monitoring METHODS: Retrospective survey of the 5600 abortion requests to the Canton Health Authority for resident women between 1990 and 1993. RESULTS: Nine women out of 1000 residents requested an abortion, but the abortion rate was higher among women of foreign origin compared to Swiss women (17/1000 vs. 6/1000, p < 0.0001). The proportion of terminated recognized conceptions was 127/1000, and the ratio of IVG to livebirths was 0.18. The abortion rate was lower during adolescence (6/1000) or after 40 years of age (1.8/1000), whereas the proportion of terminated conceptions was highest at these ages (527/1000 and 312/1000). Abortion utilization in Canton of Vaud is among the lowest. CONCLUSIONS: Although these indicators do reflect a satisfactory accessibility and use of family planning services, improvements could be made. A better knowledge of the causes (motives, contraceptive method, reproductive history) and of the consequences of abortion (psycho-social implications, medical complications) would allow to design more focused prevention strategies and to fit health services to current needs. Updating the 1942 Swiss legislation is also desirable. 相似文献
9.
OBJECTIVE: The aim of this study was to evaluate both the importance of the screening strategy and the familial aggregation characteristics of families with hypercholesterolemic children. PATIENTS AND METHODS: Ninety-one families (369 subjects) with one hypercholesterolemic child were studied. In addition to clinical and general biochemical evaluation, lipids including apo A-I and B-100 were examined. LDL was quantified under ultracentrifugation. RESULTS: Among the 91 children studied, 10 (10.99%) suffered heterozygous hypercholesterolemia, while 81 (89.01%) suffered polygenic hypercholesterolemia. Following a diet, polygenic children exhibited normal lipid parameters. In heterozygous children a decrease of 19% for total cholesterol, 19.9% for LDL-cholesterol and 16.3% for apo B were observed. When starting the study, 77.5% of the family members thought that they had normal serum lipid values. At the end of the study it was confirmed that only 28% were really normolipemic, indicating that 49.4% of the individual did not know that they were suffering dyslipemia. The study also showed that fathers exhibited the highest incidence of hypercholesterolemia (80.2%) followed by brothers (65.6%) and mothers (61.5%). Therefore, 69.4% of the individuals studied exhibited dyslipemia. CONCLUSIONS: The screening strategy allows one to diagnose a high percentage (almost 50%) of individuals suffering hypercholesterolemia in families with a child previously diagnosed of this pathology. Moreover, in these families there is a high degree of familiar aggregation of dyslipemia. 相似文献
10.