首页 | 本学科首页   官方微博 | 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   1791848篇
  免费   134629篇
  国内免费   10303篇
耳鼻咽喉   22515篇
儿科学   57263篇
妇产科学   47103篇
基础医学   249486篇
口腔科学   50597篇
临床医学   165067篇
内科学   344292篇
皮肤病学   39631篇
神经病学   134262篇
特种医学   67266篇
外国民族医学   278篇
外科学   263587篇
综合类   61396篇
现状与发展   38篇
一般理论   532篇
预防医学   134158篇
眼科学   42901篇
药学   135659篇
  194篇
中国医学   13219篇
肿瘤学   107336篇
  2021年   18191篇
  2020年   12627篇
  2019年   16692篇
  2018年   23148篇
  2017年   18960篇
  2016年   19599篇
  2015年   23881篇
  2014年   32301篇
  2013年   44489篇
  2012年   61896篇
  2011年   65140篇
  2010年   39968篇
  2009年   36573篇
  2008年   57853篇
  2007年   60669篇
  2006年   60650篇
  2005年   56721篇
  2004年   53544篇
  2003年   50730篇
  2002年   48315篇
  2001年   93330篇
  2000年   94771篇
  1999年   77771篇
  1998年   20149篇
  1997年   17672篇
  1996年   17685篇
  1995年   17033篇
  1994年   15504篇
  1993年   14166篇
  1992年   57460篇
  1991年   55339篇
  1990年   53037篇
  1989年   50791篇
  1988年   46183篇
  1987年   44970篇
  1986年   42245篇
  1985年   39997篇
  1984年   29354篇
  1983年   24910篇
  1982年   13902篇
  1979年   25533篇
  1978年   17575篇
  1977年   14907篇
  1976年   13874篇
  1975年   14563篇
  1974年   17631篇
  1973年   16944篇
  1972年   15673篇
  1971年   14453篇
  1970年   13431篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α, and interleukin-6. Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1β and BMD at all sites. Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. Conclusions These findings may have therapeutic implications for enhancing bone density in these patients.  相似文献   
143.
144.
Our group have studied a patient affected by a malignant schwannoma in the posterior tibial nerve. Schwannomas are uncommon neoplasms that originate from the Schwann cells of the peripheral nerves: the most common forms are benign. Malignant transformation is rarer. The therapy is surgical and the operation undertaken, if possible, should be the amputation. Alternatively, where amputation is not possible due to the specific localisation or due to patient refusal, the alternative must be the largest and most radical excision possible.  相似文献   
145.
146.
147.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population.  相似文献   
148.
Zusammenfassung Dieser Artikel stellt eine Übersetzung der im Jahr 2006 herausgegebenen Empfehlungen zur Behandlung von Patienten mit spontaner intrazerebraler Blutung der Europäischen Schlaganfallinitiative (EUSI) für das Europäische Schlaganfall-Council (ESC), die Europäische Neurologische Gesellschaft (ENS) und die Europäische Förderation Neurologischer Gesellschaften (EFNS) dar.Diese EUSI-Empfehlungen werden von dem European Stroke Council (ESC), der European Neurological Society (ENS) und der European Federation of Neurological Societies (EFNS) unterstützt.  相似文献   
149.
150.
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