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   933397篇
  免费   67743篇
  国内免费   1346篇
耳鼻咽喉   12975篇
儿科学   24426篇
妇产科学   23310篇
基础医学   133183篇
口腔科学   28271篇
临床医学   81051篇
内科学   183722篇
皮肤病学   19261篇
神经病学   72396篇
特种医学   36899篇
外国民族医学   79篇
外科学   152486篇
综合类   18093篇
现状与发展   1篇
一般理论   247篇
预防医学   62068篇
眼科学   21386篇
药学   72740篇
  3篇
中国医学   2164篇
肿瘤学   57725篇
  2018年   9007篇
  2017年   7072篇
  2016年   7812篇
  2015年   8908篇
  2014年   12055篇
  2013年   17605篇
  2012年   24196篇
  2011年   25191篇
  2010年   14879篇
  2009年   14336篇
  2008年   24729篇
  2007年   25826篇
  2006年   26618篇
  2005年   25589篇
  2004年   24673篇
  2003年   23734篇
  2002年   23244篇
  2001年   54805篇
  2000年   56623篇
  1999年   47015篇
  1998年   10755篇
  1997年   9493篇
  1996年   9611篇
  1995年   8946篇
  1994年   8304篇
  1993年   7624篇
  1992年   35544篇
  1991年   33967篇
  1990年   32793篇
  1989年   31927篇
  1988年   29045篇
  1987年   28288篇
  1986年   26318篇
  1985年   25188篇
  1984年   17860篇
  1983年   15168篇
  1982年   7809篇
  1981年   6786篇
  1979年   15807篇
  1978年   10621篇
  1977年   9066篇
  1976年   7890篇
  1975年   8639篇
  1974年   10482篇
  1973年   9870篇
  1972年   9373篇
  1971年   8861篇
  1970年   8442篇
  1969年   7935篇
  1968年   7213篇
排序方式: 共有10000条查询结果,搜索用时 31 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