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   931715篇
  免费   67542篇
  国内免费   1351篇
耳鼻咽喉   12984篇
儿科学   24366篇
妇产科学   23234篇
基础医学   132978篇
口腔科学   28356篇
临床医学   80605篇
内科学   183512篇
皮肤病学   19242篇
神经病学   72298篇
特种医学   36828篇
外国民族医学   79篇
外科学   152312篇
综合类   18047篇
现状与发展   1篇
一般理论   234篇
预防医学   61761篇
眼科学   21317篇
药学   72563篇
  3篇
中国医学   2163篇
肿瘤学   57725篇
  2018年   8982篇
  2017年   7040篇
  2016年   7771篇
  2015年   8888篇
  2014年   12004篇
  2013年   17529篇
  2012年   24141篇
  2011年   25092篇
  2010年   14825篇
  2009年   14298篇
  2008年   24648篇
  2007年   25752篇
  2006年   26539篇
  2005年   25489篇
  2004年   24614篇
  2003年   23637篇
  2002年   23210篇
  2001年   54757篇
  2000年   56576篇
  1999年   46975篇
  1998年   10743篇
  1997年   9480篇
  1996年   9609篇
  1995年   8932篇
  1994年   8286篇
  1993年   7597篇
  1992年   35505篇
  1991年   33931篇
  1990年   32743篇
  1989年   31884篇
  1988年   29005篇
  1987年   28261篇
  1986年   26297篇
  1985年   25151篇
  1984年   17845篇
  1983年   15148篇
  1982年   7798篇
  1981年   6774篇
  1979年   15793篇
  1978年   10600篇
  1977年   9059篇
  1976年   7874篇
  1975年   8632篇
  1974年   10469篇
  1973年   9861篇
  1972年   9359篇
  1971年   8856篇
  1970年   8428篇
  1969年   7927篇
  1968年   7203篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
31.
32.
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.  相似文献   
33.
Annals of Nuclear Medicine - The Response Evaluation Criteria In Solid Tumors (RECIST) is the most used radiological method for evaluating response after peptide receptor radionuclide therapy...  相似文献   
34.
35.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  相似文献   
36.
37.
38.
39.
40.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  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