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Abstract: Data from the National Education Longitudinal Study were combined with census data at the zip code level to examine the impact of neighborhood racial and ethnic diversity and consolidated inequality, in addition to individual, family, and school factors, on the likelihood of dropping out of high school. Results indicate that while the effects for diversity and consolidated inequality did not support the stated hypotheses, main effects for family risk and prior academic achievement were significant and in the stated direction. Also, when controlling for individual, family, school, and neighborhood characteristics, African Americans were less likely than White students to drop out of school. Implications for contextual effects research and educational outcomes are discussed.  相似文献   
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This review focuses on selected areas that should interest both the scientist and the clinician alike: polymorphisms within the factor VIII and factor IX genes, their linkage, and their ethnic variation; a general assessment of mutations within both genes and a detailed inspection of the molecular pathology of certain mutations to illustrate the diverse cause–effect relations that exist; a summary of current knowledge on molecular aspects of inhibitor production; and an introduction to the new areas of factor VIII and factor IX catabolism. An appendix defining various terms encountered in the molecular genetics of the haemophilias is included, together with an appendix providing accession numbers and locus identification links for accessing gene and sequence information in the international nucleic acid databases.  相似文献   
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To better understand the potential environmental health risk presented by West Nile virus (WNV)-contaminated feces, we quantified the amount of WNV present in the feces of experimentally infected American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus). Peak fecal titers ranged from 10(3.5) to 10(8.8) plaque-forming units (PFU)/g for 10 American crows and from 10(2.3) to 10(6.4) PFU/g for 10 fish crows. The presence of infectious WNV in bird feces indicates a potential for direct transmission of WNV. Thus, handlers of sick or dead birds should take appropriate precautions to avoid exposure to fecal material.  相似文献   
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胰岛素抵抗和脑血管病关系的研究   总被引:1,自引:0,他引:1  
苗博文  田桂玲 《天津医药》2005,33(11):688-689
目的:探讨胰岛素抵抗与脑梗死、脑出血的关系,为针对胰岛素抵抗的治疗可以有效地预防脑血管疾病提供理论依据。方法:选取42例脑梗死(脑梗死组)、40例脑出血(脑出血组)及30例非脑血管病患者(对照组),分别测定空腹胰岛素(FINS)、空腹血糖(FBG),计算胰岛素敏感指数(ISI),各组间进行比较。结果:脑梗死组和脑出血组患者ISI低于对照组(P〈0.05),而FINS高于对照组(P〈0.05),FBG与对照组差异无统计学意义(P〉0.05)。结论:胰岛素抵抗可能是脑血管病的一个重要危险因素。  相似文献   
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BASIS: Fractures of the talus or calcaneus with accompanying soft tissue damage require precisely planned treatment to prevent infection of the wound over time, especially in severely injured patients. MATERIAL AND METHODS: Seven patients with fractures of the talus or calcaneus and accompanying 2nd and 3rd degree open or 3rd degree closed soft tissue injuries were followed up retrospectively. These patients were operated on between January 1999 and January 2006 with free fasciocutaneous scapular or parascapular flaps. The average age was 34 (range 16-54). Follow-up was at 6-36 months. RESULTS: Osteosynthesis was primarily in six cases, post-primarily in one, and in four cases exterior fixation was used additively. Temporary vacuum therapy was performed for a mean of 28 days (6-42). Parascapular, scapular, and Latissimus dorsi flap coverage was performed six, one, and one times, respectively. Six flaps healed without complication. One necrosis of a parascapular flap occurred and made a Latissimus dorsi flap necessary. In one case of donor-site wound dehiscense, a local rotation flap became necessary. There was no joint infection or osteomyelitis. Bony consolidation was achieved within all fractures. CONCLUSION: Traumatic soft tissue damage must be taken into account when primary or secondary internal fixation is performed and should influence the choice of implant. Free fasciocutaneous parascapular or scapular flaps are a powerful tool for preventing infection if local flaps are not sufficient to achieve stable soft tissue coverage.  相似文献   
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Intravesical doxorubicin rarely has been implicated as a cause of bladder contracture. We present a case of severe bladder contracture, documented radiographically and urodynamically after 8 weekly intravesical instillations of doxorubicin. The patient subsequently underwent cystectomy because of voiding dysfunction and the specimen demonstrated marked fibrosis in the bladder wall. We postulate that a benign, recurrent bladder ulceration during doxorubicin therapy may have potentiated the fibrotic response in the bladder to the doxorubicin. Objective monitoring of bladder capacity should be considered in patients treated with intravesical chemotherapy.  相似文献   
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There is evidence that long-term maintenance of a low-fat diet reduces preference for high-fat foods. Sensory evaluation of the taste of fat, and preference for high and low-fat foods were studied in a group of former participants in a randomized dietary intervention trial aimed at lowering fat consumption. Intervention subjects consuming less than 25% of daily calories as fat and control subjects consuming more than 35% of daily calories as fat agreed to be in a "taste perception" study. In Study 1, subjects tasted 20 dairy solutions containing different levels of fat and sugar. Subjects rated the perceived intensity of fat taste, and of liking, for each of the solutions. In Study 2, subjects were asked to taste and rate 4 high-fat and 4 low-fat snack foods, and were then allowed to freely consume these foods in a preference test. Intervention and control subjects were similar in their sensory evaluation of the taste of fat in Study 1. In Study 2, intervention subjects reported a reduced hedonic rating of the taste of high-fat snack foods compared to control subjects, yet intervention subjects consumed the same amount of high-fat snack foods as control subjects. We conclude that a successful outcome in a dietary intervention may be due to social and cognitive factors, in addition to potential changes in hedonic response to fat.  相似文献   
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苑玉清  蔡博文  游潮 《四川医学》2004,25(8):842-843
目的 探讨急性重型颅脑损伤 (ASBI)患者血浆中内皮素 (ET)和降钙素基因相关肽 (CGRP)的含量变化及其临床意义。方法 用放免法测定 2 8例ASBI患者伤后 6~ 2 4h血浆中ET及CGRP含量。结果 ASBI患者ET含量明显增多 ,差别有显著性 (P <0 .0 5 ) ;CGRP也有一定的增多 ,但无显著性差异。结论 ET和CGRP共同参与ASBI病理生理反应过程 ,ET释放增加是加重脑继发性损害的重要因素  相似文献   
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