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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
Hypoxemia is associated with mitochondrial DNA damage and gene induction. Implications for cardiac disease 总被引:24,自引:0,他引:24
M Corral-Debrinski G Stepien J M Shoffner M T Lott K Kanter D C Wallace 《JAMA》1991,266(13):1812-1816
892.
Harold C. Lyon Jr. James C. Healy James R. Bell Joseph F. O'Donnell Edward K. Shultz Robert S. Wigton Frank Hirai J. Robert Beck 《Journal of medical systems》1991,15(2):117-132
Richard E. Clark in his widely published comprehensive studies and meta-analyses of the literature on computer assisted instruction (CAI) has decried the lack of carefully controlled research, challenging almost every study which shows the computer-based intervention to result in significant post-test proficiency gains over a non-computer-based intervention. We report on a randomized study in a medical school setting where the usual confounders found by Clark to plague most research, were carefully controlled. PlanAlyzer is a microcomputer-based, self-paced, case-based, event-driven system for medical education which was developed and used in carefully controlled trials in a second year medical school curriculum to test the hypothesis that students with access to the interactive programs could integrate their didactic knowledge more effectively and/or efficiently than with access only to traditional textual “nonintelligent” materials. PlanAlyzer presents cases, elicits and critiques a student's approach to the diagnosis of two common medical disorders: anemias and chest pain. PlanAlyzer uses text, hypertext, images and critiquing theory. Students were randomized, one half becoming the experimental group who received the interactive PlanAlyzer cases in anemia, the other half becoming the controls who received the exact same content material in a text format. Later in each year there was a crossover, the controls becoming the experimentals for a similar intervention with the cardiology PlanAlyzer cases. Preliminary results at the end of the first two full trials shows that the programs have achieved most of the proposed instructional objectives, plus some significant efficiency and economy gains. 96 faculty hours of classroom time were saved by using PlanAlyzer in their place, while maintaining high student achievement. In terms of student proficiency and efficiency, the 328 students in the trials over two years were able to accomplish the project's instructional objectives, and the experimentals accomplished this in 43% less time than the controls, achieving the same level of mastery. However, in spite of these significant efficiency findings, there have been no significant proficiency differences (as measured by current factual and higher order multiple choice post-tests) between the experimental and control groups. Very careful controls were used to avoid what Clark has found to be the most common confounders of CAI research. Accordingly, this research proved Clark's rival hypothesis, that the computer, in itself, does not appear to contribute to proficiency gains, at least as measured by our limited post-testing. Clark's position is that the computer is primarily a vehicle—as is either a pill or a hypodermic needle for delivering a drug. The hypodermic needle can deliver the drug more efficiently than can the pill, (as can the computer deliver the subject matter content more efficiently, as our research indicates), but the same content is delivered. At the same time, we proved our own hypothesis, as far as efficiency gains resulting from the computer are concerned. However, going beyond Clark's research, we may be teaching processes both more effectively and efficiently with the computer (experience in problem-solving or clinical reasoning and pattern recognition) which our current post-tests do not adequately measure. Our on-going research suggests additional inquiry in several areas: better evaluation instruments to measure the clinical reasoning skills PlanAlyzer was designed to teach; the addition of more advanced cases to determine if this might transform efficiency gains of the computer group into proficiency gains; the addition of enhanced graphic decision support tools and other pedagogical enhancements including cognitive feedback to strengthen PlanAlyzer's power to teach complex concepts of medical decision-making. 相似文献
893.
894.
895.
K Mees 《Laryngo- rhino- otologie》1989,68(1):12-18
Free microvascular anastomosed tissue transfer has improved the reconstruction of soft tissue defects dramatically. For reconstruction of facial and cervical soft tissue defects numerous free flaps are available to the head and neck surgeon, however, most of the reconstructive problems can be solved by using a limited number of reliable and versatile techniques. In microvascular tissue transfer, the scapular flap offers similar advantages as to reliability and versatility as the pectoralis major flap in pedicled tissue transfer. In contrast to the scapular flap the groin flap is more bulky, its skin is soft and may carry pubic hair on its medial aspect. After partial maxillectomy or in facial dysplasia facial contour may be restored satisfactory with a completely or partially de-epithelialized scapular flap. In total hypopharyngeal and cervicoesophageal defects the jejunum transplant provides an ideal tubular replacement. If after resection of an intraoral carcinoma with partial mandibulectomy an osteocutaneous transfer has to be achieved the mandibular defect may be reconstructed with bone from the iliac crest or from the radius while the intra- and extraoral tissue defect may be closed with the adjacent skin flaps. For the closure of large penetrating defects of the cheek the inferior epigastric abdominal wall flap in particular has proved a versatile and reliable flap. This flap offers both, a cutaneous and a peritoneal surface. Latter is used for the replacement of the intraoral lining. 相似文献
896.
The question of the necessity of in-patient facilities of the area of (child and) adolescent neuropsychiatry is to be discussed further. The extremely optimistic views on this question of approximately 20 years ago cannot be maintained for the examined area and the examination time. In the LNKH Valduna/Vorarlberg, an establishment that was intended exclusively for adults until 1987, from 1980-1984 (evaluated in detail) and from 1984-1987 a further 60 minors were admitted. The exact evaluation shows that the conspicuousnesses of behaviour of a main group was so clear each time that it could not be treated elsewhere and certainly not in outpatient facilities. In the examined group the amount of patients with behaviour and socialization disorders outweighed by far the psychoses, also a high percentage of patients was multi morbid and/or had multiple handicaps. The resulting conclusion seems to us to be the necessity of setting-up a specific in-patients treatment unit for this group of patients with sufficient infrastructure. 相似文献
897.
898.
899.
Influence of pyrazine derivatives on the day of vaginal opening in juvenile female rats 总被引:1,自引:0,他引:1
Effects of pyrazine derivatives on the day of the first opening of the vagina in juvenile female rats were studied. Tetraethyl and 2,5-dimethyl pyrazine caused a significant delay in the first vaginal opening day of juvenile female rats, but no delay was noted in the case of 2,5-diethyl or triethyl pyrazine. These results suggest that tetraethyl and 2,5-dimethyl pyrazine cause delays in the onset of puberty in juvenile female rats. 相似文献
900.
Inhibition of PAF-induced eosinophil accumulation in pulmonary airways of guinea pigs by anti-asthma drugs 总被引:3,自引:0,他引:3
S Sanjar S Aoki K Boubekeur L Burrows I Colditz I Chapman J Morley 《Japanese journal of pharmacology》1989,51(2):167-172
Intraperitoneal (i.p.) injection of platelet activating factor (PAF) in guinea pigs caused a dose-related increase in the number of eosinophils recovered from bronchoalveolar lavage fluid (BALF). The prevalence of eosinophils in BALF had significantly increased within 1 hr of i.p. injection of PAF (10 micrograms/animal) and was maximal after 24 hr. Subcutaneous osmotic mini-pumps were used to administer drugs for 5 days prior to i.p. injection of PAF (10 micrograms/animal) and for the subsequent 24 hr. The percentage increase of eosinophils in BALF, due to PAF, was inhibited in animals treated with dexamethasone, aminophylline, cromoglycate, tranilast or ketotifen, but not in animals treated with oxatomide, azelastine, amlexanox, ibudilast or AA-861. These results suggest that inhibition of pulmonary eosinophilia may be a necessary property of prophylactic anti-asthma drugs and provide indirect evidence favoring a role for PAF in eosinophilia of asthma. 相似文献