首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7245篇
  免费   883篇
  国内免费   176篇
医药卫生   8304篇
  2024年   13篇
  2023年   197篇
  2022年   161篇
  2021年   346篇
  2020年   406篇
  2019年   405篇
  2018年   368篇
  2017年   327篇
  2016年   324篇
  2015年   302篇
  2014年   436篇
  2013年   629篇
  2012年   348篇
  2011年   377篇
  2010年   373篇
  2009年   325篇
  2008年   347篇
  2007年   368篇
  2006年   271篇
  2005年   240篇
  2004年   208篇
  2003年   183篇
  2002年   150篇
  2001年   144篇
  2000年   109篇
  1999年   78篇
  1998年   87篇
  1997年   72篇
  1996年   63篇
  1995年   67篇
  1994年   60篇
  1993年   45篇
  1992年   51篇
  1991年   49篇
  1990年   47篇
  1989年   54篇
  1988年   25篇
  1987年   23篇
  1986年   27篇
  1985年   55篇
  1984年   32篇
  1983年   16篇
  1982年   20篇
  1981年   22篇
  1980年   9篇
  1979年   10篇
  1978年   6篇
  1977年   8篇
  1976年   7篇
  1973年   4篇
排序方式: 共有8304条查询结果,搜索用时 31 毫秒
11.
Milk is a liquid food that possesses an important quantity of highly bioavailable macronutrients. In addition, it is readily accessible, as well as relatively inexpensive. Given that the knowledge of physicians about nutrition and food composition is deficient, in general, many of the dietary interventions recommended in diverse clinical settings lack a scientific basis. The aim of the present review was to produce a technical opinion that serves as a frame of reference to best sustain recommendations for consuming milk and dairy products as daily nutrition in the adult and older adult. The effects of milk and dairy products during the pediatric stage are not addressed in the present work. The Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Gerontología y Geriatría jointly discussed and analyzed topics dealing with the legal designation of milk, the classification and nutritional profile of cow's milk, its nutritional characteristics, its consumption in the adult, intolerance to cow's milk, and associations of milk consumption with digestive tract alterations and other conditions. Finally, certain aspects of milk consumption in the older adult and its relation to overall health are briefly discussed.  相似文献   
12.
We developed a self-administered questionnaire for screening the most common adult-onset dystonias. It was tested in 90 first-degree relatives of 22 adult-onset dystonia patients, yielding 79% sensitivity and 94% specificity. Simulation of a case-finding procedure based on serial application of the questionnaire and clinical examination of both subjects screening positive and subjects screening negative who had < 8 years of schooling increased sensitivity to 95% and specificity to 100%. This questionnaire may be an important screening resource for familial aggregation studies to be used in the context of a complex case-finding procedure.  相似文献   
13.
仡佬族成人指纹白线的研究   总被引:5,自引:3,他引:2  
目的 探讨仡佬族成人指纹白线的特征 ,为法医学、人类学及临床医学提供参考资料。方法 对贵州省道真县三代均为仡佬族的 2 17名成年人的 43 4侧手、2 170个手指指纹白线出现率进行了观测和统计分析。结果 各指指纹白线出现率为 :男 2 .48% ,女 2 .76% ;每个人指纹白线出现率 (每人有一指以上出现者 )为 :男 17.82 % ,女 18.10 % ;每只手指纹白线出现率 (每指有一条白线以上出现者 )为 :男 10 .89% ,女 11.2 1% ;每只手指指纹白线分布率为 :男 2 .48% ,女 2 .76% ;男女间差异无显著性 ,P >0 .0 5。结论 仡佬族成年人指纹白线出现率较低 ,并以单手、单指、单条白线分布为主。  相似文献   
14.
目的 :分离日本血吸虫感染及免疫血清识别的成虫抗原 (AWA)中的特异蛋白带 ,为血吸虫病免疫诊断提供新的抗原分子。方法 :免疫印迹法分析AWA的特异蛋白带 ,电泳层析法分离靶抗原。结果 :获得了感染血清和免疫血清识别的 6 7kD蛋白。结论 :电泳层析法是一种分离血吸虫抗原的有效方法  相似文献   
15.
目的探讨成人水痘的临床特点。方法分析20例成人水痘的临床特点,并与30例儿童水痘比较。结果患者出疹时间、皮疹分布区域、发热时间和并发症等,成人水痘都与儿童水痘不同。结论与儿童水痘相比较,成人水痘有自己的临床特点。  相似文献   
16.
We report adult congenital bronchoesophageal fistula with both symptomatic fistula and asymptomatic one. A 56-year-old woman with a history of cough after drinking fluids was diagnosed as bronchoesophageal fistula by upper gastrointestinal series that showed a diverticulum in the middle portion of the esophagus with a fistula between the esophagus and right lower lung. Esophagoscopy revealed an orifice of the fistula located 27 cm from the incisors. Computed tomography showed chronic inflammatory change with bronchiectasis in the S6 segment of the right lung. The patient underwent video assisted thoracic surgery that identified two fistulae without missing a symptomatic one, and both were successfully resected. The fistulae were lined by squamous epithelium and smooth muscle without evidence of malignancy, infection or chronic inflammation that were histologically compatible with congenital fistulae.  相似文献   
17.
18.
Elevation of plasma thioredoxin levels in HIV-infected individuals   总被引:3,自引:0,他引:3  
Thioredoxin (Trx), a ubiquitous protein intimately involvedin redox and protein disulfide reductions, has been shown tobe released from cells and to have cytokine-like activities.In addition, Trx has been implicated in the redox regulationof immunological responses and shown to be deficient in tissuesfrom AIDS patients. In studies presented here, plasma Trx levelswere measured by ELISA in plasma samples from HIV-infected individuals(n = 136) and HIV-negative controls (n = 47). To account forthe release of Trx into plasma due to hemolysis, the Trx measurementswere corrected according to the level of hemoglobin in the plasmasample. Data presented show that, in contrast to tissue Trxlevels, corrected plasma Trx levels are significantly higherin HIV-infected individuals than in controls (P < 0.0001).Furthermore, {small tilde}25% of the HIV-infected individualsstudied have plasma Trx levels greater than the highest levelfound in controls (37 ng/ml). Detailed multiparameter FACS analysisof peripheral blood mononuclear cells (PBMC) from the infectedindividuals demonstrates that those with higher plasma Trx levels(37 ng/ml or greater) tend to have lower overall CD4 counts.In addition, increases in plasma Trx levels correlate with decreasesin monochlorobimane staining (indicative of lower intracellularglutathione levels in PBMC) and with changes in surface antigenexpression (CD62L, CD38 and CD20) that occur in the later stagesof HIV infection. These correlations suggest that elevationof plasma Trx levels may be an important component of advancedHIV disease, perhaps related to the oxidative stress that oftenoccurs at this stage.  相似文献   
19.
Omeprazole is a substituted benzimidazole that causes dose-dependent intracellular inhibition of gastric acid secretion in humans. This double-blind study examined the effect of omeprazole in decreasing gastric acidity and gastric residual volume in outpatient adults. Unpremedicated outpatients, ASA I-III, 18 years or older (n = 17), were randomly assigned to receive omeprazole 80 mg, or placebo by mouth the night before scheduled elective outpatient surgery. The patients were fasted for 8 h prior to surgery. After the patient was anesthetized, an orogastric tube was inserted with proper placement verified by auscultation for gastric sounds. Gastric residual contents were withdrawn into a Luken's trap, and pH was then determined and gastric volume indexed to weight (ml.kg-1). Data were analyzed by a t-test, with P less than 0.05 considered statistically significant. Patient characteristics of both groups were similar. There was a statistically significant difference between the two groups for pH (P = 0.02), but not between the two groups for gastric volume indexed to weight (P = 0.07).  相似文献   
20.
OBJECTIVE: The aim of this study was to evaluate the long-term results of the Antegrade Continent Enema (ACE) procedure for treating severe constipation in adults. METHODS: Over 10 years 37 ACE conduits were created in 32 patients (median age 35 years, 26 women) with constipation caused by slow transit, obstructed defaecation or both. Conduits were created from the appendix (n = 20, 54%), ileum (n = 10, 27%), neoappendix caecostomy (n = 5, 14%) or colon (n = 2, 5%). Clinical records were retrospectively reviewed to determine outcome. RESULTS: After a median follow up of 36 (range 13-140) months, 28 (88%) required at least one further procedure on a primary conduit, including reversal in 19 (59%). Five patients had a second conduit fashioned, two successfully. Conduit type and constipation cause did not significantly influence the rates of ACE reversal or major revision. Ileal conduits were associated with fewer minor revision procedures for stenosis (1 in 7 patients) than appendix conduits (21 in 20 patients). There was one (3%) serious complication. Satisfactory ACE function was ultimately achieved in 47% of patients, at last follow up. After ACE reversal, 9 (28%) patients underwent formation of an end stoma and 3 patients had a colectomy. CONCLUSIONS: Revision procedures are common, but approximately half of patients can expect satisfactory long-term ACE function. ACE conduit reversal does not preclude subsequent alternative surgical strategies to treat this difficult condition.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号