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   2192955篇
  免费   151011篇
  国内免费   3505篇
耳鼻咽喉   31474篇
儿科学   67569篇
妇产科学   61696篇
基础医学   313979篇
口腔科学   64281篇
临床医学   186850篇
内科学   425727篇
皮肤病学   46183篇
神经病学   168464篇
特种医学   88672篇
外国民族医学   531篇
外科学   345695篇
综合类   42467篇
现状与发展   2篇
一般理论   515篇
预防医学   157176篇
眼科学   50627篇
药学   168434篇
  5篇
中国医学   4401篇
肿瘤学   122723篇
  2018年   22370篇
  2017年   18217篇
  2016年   19232篇
  2015年   23051篇
  2014年   29453篇
  2013年   41801篇
  2012年   61569篇
  2011年   60644篇
  2010年   35415篇
  2009年   34967篇
  2008年   56978篇
  2007年   61435篇
  2006年   62621篇
  2005年   68305篇
  2004年   67679篇
  2003年   61769篇
  2002年   56541篇
  2001年   104991篇
  2000年   106795篇
  1999年   92546篇
  1998年   23532篇
  1997年   20763篇
  1996年   21033篇
  1995年   19759篇
  1994年   18615篇
  1993年   17178篇
  1992年   74479篇
  1991年   72767篇
  1990年   71477篇
  1989年   69528篇
  1988年   64367篇
  1987年   62738篇
  1986年   59428篇
  1985年   56637篇
  1984年   41209篇
  1983年   35321篇
  1982年   19490篇
  1979年   38482篇
  1978年   26452篇
  1977年   22625篇
  1976年   20637篇
  1975年   23215篇
  1974年   27865篇
  1973年   26419篇
  1972年   25323篇
  1971年   23806篇
  1970年   22400篇
  1969年   21480篇
  1968年   19878篇
  1967年   17760篇
排序方式: 共有10000条查询结果,搜索用时 984 毫秒
71.
72.
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   
73.
74.
75.
76.
77.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  相似文献   
78.
79.
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   
80.
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