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   633篇
  免费   25篇
  国内免费   2篇
儿科学   11篇
基础医学   28篇
口腔科学   6篇
临床医学   17篇
内科学   164篇
皮肤病学   5篇
神经病学   4篇
特种医学   9篇
外科学   56篇
综合类   15篇
预防医学   31篇
眼科学   7篇
药学   37篇
中国医学   2篇
肿瘤学   268篇
  2023年   2篇
  2022年   5篇
  2021年   13篇
  2020年   7篇
  2019年   9篇
  2018年   17篇
  2017年   4篇
  2016年   8篇
  2015年   15篇
  2014年   21篇
  2013年   12篇
  2012年   35篇
  2011年   28篇
  2010年   20篇
  2009年   23篇
  2008年   39篇
  2007年   33篇
  2006年   46篇
  2005年   55篇
  2004年   34篇
  2003年   28篇
  2002年   33篇
  2001年   21篇
  2000年   20篇
  1999年   25篇
  1998年   10篇
  1997年   4篇
  1996年   2篇
  1995年   3篇
  1994年   4篇
  1993年   4篇
  1992年   8篇
  1991年   9篇
  1990年   8篇
  1989年   13篇
  1988年   9篇
  1987年   6篇
  1986年   12篇
  1985年   5篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1979年   1篇
  1977年   2篇
  1976年   3篇
排序方式: 共有660条查询结果,搜索用时 15 毫秒
1.
Hyperlipidemia is a major risk factor in etiology of cardiovascular disease. Previous studies have shown association between vegetarian diet and low total serum cholesterol as well as LDL-cholesterol which is a pointer to low risk of cardiovascular disease. Dietary fiber, antioxidants and other classes of nutrients have been reported to ameliorate cardiovascular risk factors. Fruits and vegetables being rich sources of fiber and antioxidants have been the focus in intervention studies. The current work reports the effect local fruits and vegetables on cardiovascular risk factors in African hypertensive subjects in an 8 week study. Though there was no significant difference in the Body Mass Index and HDL-cholesterol at the end of the eighth week, there were significant reductions (P < 0.05) in serum triglycerides (125.87 ± 6.0 to108.27 ± 5.49 mgdL-1); total serum cholesterol (226.60 ± 6.15 to 179.20 ± 5.78) and LDL-cholesterol (135.69 ± 5.56 to 93.07 ± 7.18 mgdL-1). We concluded that consumption of combination of local fruits and vegetables may reduce the incidence of cardiovascular risk factors in Africans.  相似文献   
2.
3.
4.
Background Significant tumor downstaging has been achieved in patients with localized gastric or gastroesophageal adenocarcinoma by induction chemotherapy and preoperative chemoradiotherapy (CTX–CTXRT). However, the influence of CTX–CTXRT on operative morbidity and mortality has not yet been clarified. The aim of the present study was to document the frequency and nature of morbidity and mortality after surgery combined with CTX–CTXRT, and identify factors predictive of postoperative complications in patients with localized gastric or gastroesophageal adenocarcinoma. Methods A prospectively collected database on 71 consecutive patients who underwent CTX–CTXRT at M.D. Anderson Cancer Center between January 1997 and August 2004 was reviewed. Postoperative morbidity and mortality were investigated, and risk factors for overall complications were identified by multivariate logistic regression analysis. Results Overall morbidity and mortality rates were 38.0% (27 patients) and 2.8% (2 patients), respectively. Age greater than 60 years [relative risk 11.3 (95% confidence interval 2.50–50.6)] and body mass index (BMI) of 26 kg/m2 or above [relative risk 4.08 (95% confidence interval 1.08–15.4)] were significant risk factors for overall complications. Conclusions CTX–CTXRT can be performed safely with an acceptable operative morbidity and a low operative mortality rate in patients with gastric or gastroesophageal cancer, with careful consideration of added risk associated with age and obesity.  相似文献   
5.
6.
OBJECTIVE: To examine glucose tolerance in sputum-positive non-treated pulmonary tuberculosis (TB) patients as part of a general metabolic profile. Subjects. Sixty-three sputum-positive non-treated patients (male and female) attending the pulmonary clinic at Mthatha General Hospital in the Eastern Cape and 89 apparently healthy sex and age-matched volunteers. METHODS: Sixty-three untreated TB patients who came to the Mthatha General Hospital's pulmonary clinic with classic symptoms of TB, confirmed by sputum analysis, were recruited for the study. Eighty-nine apparently healthy sex and age-matched volunteers served as the control group. Anthropometric measurements were taken using an electronic scale. Standard oral glucose tolerance tests (OGTTs) were performed in both groups in the morning after an overnight fast. Anticoagulant-treated blood was analysed for glucose and insulin using Peridochrome Glucose (Boehringer Mannheim, Mannheim, Germany) and radioimmunoassay (RIA) (Diagnostic Products Corporation, Los Angeles, USA) respectively. RESULTS: There was sluggish response to glucose and insulin in the TB patient group compared with the control group. Glucose and insulin levels were significantly higher in patients at 0, 30, 60, 120, and 180 minutes. Analysis of variance gave the following p-values, viz. p = 0.0000, 0.0004, 0.0000, 0.0000 and 0.0000 for glucose, and p = 0.0317, 0.0071, 0.0000, 0.0005 and 0.0000 for insulin respectively. CONCLUSIONS: The results of this study suggest an altered glucose/insulin metabolism in TB patients. This might play an important role in the clinical course of the disease.  相似文献   
7.
The effect of a continuous i.v. infusion of alpha-difluoromethylornithine (DFMO) on the polyamine metabolism of tumor and normal host tissue was determined. Non-tumor-bearing Fischer 344 rats or rats bearing a transplantable fibrosarcoma received continuous infusions of DFMO through a central venous catheter at three dose levels. Treatment with DFMO resulted in a time- and dose-dependent, cytostatic effect on the growth of the tumor. In fibrosarcoma-bearing rats the tumor putrescine levels were reduced after 6 and 12 days of DFMO treatment. Tumor spermidine levels were consistently reduced after 6 and 12 days of treatment with the reduction being dose dependent. The decrease in tumor ornithine decarboxylase activity was dose dependent. Erythrocyte putrescine levels were decreased in tumor- and non-tumor-bearing rats, suggesting that DFMO reduces the tumor contribution to the erythrocyte pool. Erythrocyte spermidine levels of fibrosarcoma- and non-tumor-bearing rats were elevated at the lower DFMO doses administered for 12 days but returned to normal as the dose was increased. Erythrocyte spermine levels were elevated in both groups of rats at all DFMO doses. Although normal host tissue weights were not affected by treatment with DFMO, the putrescine and spermidine levels of liver, spleen, and kidney and ornithine decarboxylase activity of the liver and kidney were decreased. These data demonstrate that i.v. DFMO has a cytostatic effect toward a rapidly growing fibrosarcoma associated with the depletion of both tumor putrescine and spermidine levels.  相似文献   
8.
9.
10.
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