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   2060篇
  免费   225篇
  国内免费   69篇
耳鼻咽喉   3篇
儿科学   87篇
妇产科学   21篇
基础医学   274篇
口腔科学   61篇
临床医学   260篇
内科学   470篇
皮肤病学   5篇
神经病学   129篇
特种医学   128篇
外科学   211篇
综合类   51篇
预防医学   350篇
眼科学   11篇
药学   194篇
中国医学   2篇
肿瘤学   97篇
  2021年   31篇
  2020年   19篇
  2019年   34篇
  2018年   32篇
  2017年   23篇
  2016年   27篇
  2015年   24篇
  2014年   44篇
  2013年   56篇
  2012年   86篇
  2011年   86篇
  2010年   47篇
  2009年   32篇
  2008年   61篇
  2007年   96篇
  2006年   64篇
  2005年   64篇
  2004年   65篇
  2003年   75篇
  2002年   60篇
  2001年   61篇
  2000年   56篇
  1999年   56篇
  1998年   45篇
  1997年   42篇
  1996年   41篇
  1995年   35篇
  1994年   35篇
  1993年   24篇
  1992年   54篇
  1991年   50篇
  1990年   61篇
  1989年   71篇
  1988年   64篇
  1987年   66篇
  1986年   59篇
  1985年   51篇
  1984年   53篇
  1983年   43篇
  1982年   24篇
  1981年   24篇
  1980年   19篇
  1979年   33篇
  1978年   26篇
  1977年   24篇
  1976年   26篇
  1975年   21篇
  1974年   23篇
  1973年   22篇
  1972年   16篇
排序方式: 共有2354条查询结果,搜索用时 31 毫秒
1.
2.
1. Subcutaneous injection of the kappa-opioid agonists U50,488 (10 mg kg-1) and tifluadom (3.5 mg kg-1) into Inactin-anaesthetized, saline-infused rats was associated with a diuresis, antinatriuresis and antikaliuresis which lasted for up to 2 h. A high (5 mg kg-1), but not low (0.1 mg kg-1), dose of naloxone blocked the renal effects of U50,488. 2. U50,488 administration in anaesthetized, vasopressin-deficient Brattleboro DI rats was associated with an attenuated diuresis, though the antinatriuretic response remained intact. 3. The diuretic action of U50,488 was associated with an increase in glomerular filtration rate while fractional fluid reabsorption remained steady. In contrast, fractional sodium and potassium reabsorption were increased. 4. These data suggest that kappa-opioid agonists alter renal handling of both water and electrolytes. This appears to be mediated by two separate mechanisms: increased fluid loss largely reflects altered glomerular events while the fall in electrolyte excretion results from altered tubular handling.  相似文献   
3.
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community.  相似文献   
4.
5.
6.
7.
Five patients undergoing orthotopic liver transplantation were investigated for changes in acid-base homeostasis secondary to large volume transfusions. All patients developed a transient acidemia during the operative period, followed by alkalemia which persisted into the early postoperative period. The patients received an estimated mean of 750 mEq of citrate, which appeared to cause metabolic alkalosis. The biochemical basis underlying the regulation of citrate metabolism that may have led to the timing, extent, and duration of the subsequent metabolic alkalosis is presented. Finally, the time course for the development of metabolic alkalosis may be a potentially sensitive indicator of early allograft function.  相似文献   
8.
9.
Bilateral ulnar agenesis is a rare abnormality. A total of 36 cases are analyzed: 35 of these are documented in the literature and 1 stillborn male is presented in this study. Most patients had one of the three conditions: Al-Awadi/Raas-Rothschild syndrome, syndrome of ulnar aplasia with split hand/split foot deformity, or the Brachmann—de Lange syndrome. Fifty percent of all cases with bilateral ulnar agenesis were associated with lower limb defects and these cases, for the most part, also belonged to the aforementioned syndromes. Nonskeletal, internal organ malformations were identified in 34% of all patients. Nine patients presented with isolated bilateral ulnar agenesis. The Al-Awadi/Raas-Rothschild syndrome and the split hand/split foot deformity are heritable disorders. There was no evidence for genetic etiology in most of the other cases. Bilateral ulnar agenesis in our fetus was part of the Brachmann—de Lange syndrome with associated cardiac defect, diaphragmatic hernia, and umbilical artery agenesis.  相似文献   
10.
One method used to control costs in community cardiovascular disease surveillance is to limit the number of electrocardiograms (ECGs) used to validate acute myocardial infarction (AMI). The Minnesota Heart Survey investigated the impact of decreasing the maximum number of ECGs analyzed on classification of ECG pattern and final AMI diagnosis (definite, probable, none). A 50% sample of all 1980 acute CHD hospital discharge records (ICD-9 code 410 or 411) from 30 of 31 Twin Cities hospitals were abstracted. Comparing results using all available ECGs in the record (maximum of 12) with those obtained using up to 4 ECGs showed little differences in the ECG classification or final AMI diagnosis.  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