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   282810篇
  免费   19023篇
  国内免费   1372篇
耳鼻咽喉   2966篇
儿科学   7187篇
妇产科学   5113篇
基础医学   37164篇
口腔科学   6284篇
临床医学   27481篇
内科学   59331篇
皮肤病学   4576篇
神经病学   26214篇
特种医学   11287篇
外国民族医学   6篇
外科学   43659篇
综合类   3761篇
现状与发展   3篇
一般理论   309篇
预防医学   23089篇
眼科学   6026篇
药学   19719篇
  4篇
中国医学   416篇
肿瘤学   18610篇
  2023年   1459篇
  2022年   2235篇
  2021年   5247篇
  2020年   3329篇
  2019年   5069篇
  2018年   6170篇
  2017年   4651篇
  2016年   5176篇
  2015年   6071篇
  2014年   8839篇
  2013年   12578篇
  2012年   18907篇
  2011年   20102篇
  2010年   11350篇
  2009年   10620篇
  2008年   18190篇
  2007年   19425篇
  2006年   18503篇
  2005年   18863篇
  2004年   17901篇
  2003年   16930篇
  2002年   16182篇
  2001年   2707篇
  2000年   2134篇
  1999年   2935篇
  1998年   3654篇
  1997年   2900篇
  1996年   2618篇
  1995年   2443篇
  1994年   2129篇
  1993年   2082篇
  1992年   1593篇
  1991年   1622篇
  1990年   1349篇
  1989年   1309篇
  1988年   1301篇
  1987年   1286篇
  1986年   1248篇
  1985年   1356篇
  1984年   1515篇
  1983年   1413篇
  1982年   1849篇
  1981年   1824篇
  1980年   1548篇
  1979年   986篇
  1978年   1028篇
  1977年   989篇
  1976年   851篇
  1975年   752篇
  1974年   714篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
The Enhancing Patient Prenatal Education study tested the feasibility and educational impact of an interactive program for patient prenatal genetic screening and testing education. Patients at two private practices and one public health clinic participated (N = 207). The program collected knowledge and measures of anxiety before and after use of the tool. Time in various prenatal visit activities was collected prior to and after the introduction of the education tool. Providers completed an assessment of their experiences with patients who had used the program. Results indicate that patient knowledge significantly increased from pre to post (p = .0001) with no increase in anxiety (p = .31). Time in clinic activities, including overall visit time, increased. A majority of providers indicated that the program disrupted clinic flow. This assessment suggests that the program increases patient knowledge and does not increase patient anxiety. However, challenges remain to using this program in a clinic setting.  相似文献   
84.
85.
86.
The purpose of this study was to evaluate the effects of pegfilgrastim, a long-acting granulocyte colony-stimulating factor, on the normal biodistribution of (18)F-FDG in an animal model and in humans. METHODS: Two groups of 12 rats received a single subcutaneous injection of either normal saline or pegfilgrastim. One, 7, 14, and 21 d after injection, biodistribution studies were performed 1 h after (18)F-FDG injection. Sixteen breast cancer patients underwent baseline (18)F-FDG PET/CT and, approximately 1 wk after receiving 1 dose of docetaxel and adjunctive pegfilgrastim, follow-up (18)F-FDG PET/CT (scan 2). Standardized uptake values corrected for lean body mass (SUL) were determined for several normal organs before and after therapy. RESULTS: In rats, bone marrow (18)F-FDG uptake (standardized uptake value) was higher in the pegfilgrastim group 1 d after injection (mean +/- SD, 8.3 +/- 4.1 vs. 2.5 +/- 0.2, P < 0.05), whereas (18)F-FDG uptake in blood was lower (0.41 +/- 0.06 vs. 0.49 +/- 0.01, P < 0.05). In patients, mean SUL was higher in bone marrow (4.49 +/- 1.50 vs. 1.33 +/- 0.22, P < 0.0001), spleen (3.29 +/- 0.83 vs. 1.23 +/- 0.23, P < 0.0001), and liver (1.45 +/- 0.25 vs. 1.31 +/- 0.23, P = 0.01) but lower in brain (4.18 +/- 0.76 vs. 5.14 +/- 1.44, P < 0.01) on scan 2 than on the baseline scan. CONCLUSION: In both the animal model and humans, pegfilgrastim markedly increased bone marrow uptake of (18)F-FDG and reduced (18)F-FDG uptake in some normal tissues. These profound alterations in (18)F-FDG biodistribution induced by pegfilgrastim must be considered when one is evaluating quantitative (18)F-FDG PET scans for tumor response to therapy.  相似文献   
87.
88.
The functional significance of the pars tuberalis (PT) of the mammalian adenohypophysis has remained an enigma (1, 2). One view of its function is that it acts as an auxiliary gland to support the endocrine role of the pars distalis (PD) (2), as it has been shown to contain immunocytochemically identifiable thyrotrophs and gonadotrophs (1). Many of the cells of the PT are, however, ultrastructurally unique suggesting an independent function for this tissue. Our recent demonstration that the PT of the rat is a major binding site for the ligand iodomelatonin lends further support to this idea (3). We have utilized the highly specific ligand [125l]melatonin, and have demonstrated that it binds exclusively, with very high affinity, to the PT but not the PD of the adult sheep adenohypophysis. These findings support the conclusion that the PT has a distinct role in relation to melatonin action and seasonal reproduction.  相似文献   
89.
Preclinical and clinical investigations currently underway are employing novel strategies for combining vaccines with conventional and experimental anticancer therapies. To date, the FDA has not approved a therapeutic cancer vaccine. However, the results of recent investigations suggest an increasing role for vaccines in new models of combination therapy for many types of cancer. This article reviews and discusses therapeutic cancer strategies that employ vaccines in combination with local radiation, chemotherapy, hormone therapy, and anti-CTLA-4 mAb. Preclinical studies have shown that certain anticancer agents have immune modulatory effects that result in up-regulation of surface expression of MHC molecules, tumor-associated antigens, or Fas on malignant cells, rendering them more susceptible to immune destruction. Preliminary results of clinical studies using combination strategies have demonstrated a postvaccination antigen cascade, prolonged time to disease progression, and improved overall survival. Several larger randomized trials are ongoing, and more are required to support these findings.  相似文献   
90.
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