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   1487篇
  免费   87篇
  国内免费   7篇
耳鼻咽喉   9篇
儿科学   53篇
妇产科学   7篇
基础医学   203篇
口腔科学   28篇
临床医学   86篇
内科学   431篇
皮肤病学   41篇
神经病学   128篇
特种医学   84篇
外科学   279篇
综合类   3篇
预防医学   47篇
眼科学   26篇
药学   59篇
中国医学   3篇
肿瘤学   94篇
  2022年   15篇
  2021年   26篇
  2020年   18篇
  2019年   19篇
  2018年   20篇
  2017年   31篇
  2016年   18篇
  2015年   29篇
  2014年   54篇
  2013年   58篇
  2012年   81篇
  2011年   65篇
  2010年   40篇
  2009年   19篇
  2008年   42篇
  2007年   76篇
  2006年   78篇
  2005年   84篇
  2004年   74篇
  2003年   100篇
  2002年   93篇
  2001年   64篇
  2000年   61篇
  1999年   46篇
  1998年   34篇
  1997年   19篇
  1996年   15篇
  1995年   13篇
  1994年   9篇
  1993年   12篇
  1992年   24篇
  1991年   15篇
  1990年   22篇
  1989年   22篇
  1988年   11篇
  1987年   17篇
  1986年   23篇
  1985年   11篇
  1984年   8篇
  1983年   9篇
  1982年   7篇
  1979年   11篇
  1975年   8篇
  1974年   7篇
  1973年   6篇
  1972年   7篇
  1971年   7篇
  1969年   6篇
  1968年   6篇
  1967年   7篇
排序方式: 共有1581条查询结果,搜索用时 0 毫秒
11.
A case of malignant cystosarcoma phyllodes of the prostate is reported in a 45-year-old male. This tumor was composed of benign columnar or squamous cystic folds and sarcomatous stroma including rhabdomyomatous elements. The prostatic origin of the tumor was clearly proved by the unlabeled immunoperoxidase method. ACTA PATHOL. JPN. 34: 663–668, 1984.  相似文献   
12.
Recently, many investigators have studied the effects of eicosapentaenoic acid (EPA)-rich fish oil on immune function and immune disease. However, effects of dietary supplementation of fish oil or EPA on the immune system are still unclear. In the present study, the effects of EPA on antigen presentation were investigated. We have used antigen-specific helper T-cell clones that proliferate in the presence of antigen [keyhole limpet haemocyanin (KLH)] and spleen cells as antigen-presenting cells (APC). Mice were divided into two groups and fed an experimental diet or a control diet for 4 weeks ad libitum. In mice fed the experimental diet, the arachidonic acid (AA) content of spleen cells was decreased and that of EPA and docosapentaenoic acid was increased markedly compared to those of the control diet. Dietary enrichment with EPA inhibited the ability of accessory cells to present antigen to murine helper T-cell clones. This effect was observed for two distinct helper T-cell clones, Th1 and Th2. We also examined the effects of EPA-TG emulsion on APC function. The direct addition of EPA-TG emulsion to a T-cell proliferation assay system suppressed APC function. The inhibition was proportional to the concentration of EPA-TG emulsion. Pretreatment of splenocytes with EPA-TG emulsion resulted in inhibition of APC function. Inhibition of antigen presentation by dietary supplementation with EPA might depress immune reactivity.  相似文献   
13.
14.
The secretion of tumor necrosis factor (TNF)-α from macrophages is regulated by both priming and triggering signals. We found that macrophages from mice lacking γδ T cells [T cell receptor (TCR) δ?/- mice], which lack the gene encoding the δ chain, produced only small amounts of TNF-α in response to lipopolysaccharide (LPS) and showed a reduced level of expression of CD14. Pre-incubation of macrophages from TCR δ-/- mice with γδ T cells from their TCR δ+/- littermates restored their capacity to produce TNF-α in response to LPS. The priming activity of γδ T cells was in part inhibited by neutralizing anti-interferon (IFN)-γ monoclonal antibodies. Collectively, these results suggest that γδ T cells play a role in priming macrophages to a steady state of activation via IFN-γ secretion, which allows them to produce TNF-α when exposed to LPS.  相似文献   
15.
The patient was a 65-year-old male who came to our hospital with a complaint of dysphagia. He was admitted to hospital following a diagnosis of combined tumor in the esophagus and stomach as revealed by X-ray fluoroscopy. For preoperative chemotherapy, he was given oral administration of BLM-polyacrylate pasta, 30 mg/day for 25 days and 15 mg/day for 5 days, up to a total dose of 825 mg. This regimen successfully reduced the tumor in the esophageal area. No signs of pulmonary dysfunction, changes in blood cell count and blood chemistry of any other abnormalities in his general status were seen as side-effects of the BLM-polyacrylate pasta. Thoracic-esophagectomy and total gastrectomy were performed on November 7, 1983. He has been maintaining a good quality of life without any signs of recurrence of the tumor for the last two years and six months after the operation. The esophageal tumor was identified as moderately differentiated squamous cell carcinoma with A0N0M0Pl0 and grade of invasion "mp", while the gastric tumor was moderately differentiated adenocarcinoma with H0P0S0N0 and invasion grade "m" in the early stage of IIa + IIc type.  相似文献   
16.
The chemical and radio toxicity of 125-5-iodo-2-deoxyuridine (125IUDR) on 870127T human lung cancer (HLC) cells grown in tissue cultures and the quantitative analysis of the distribution and fate of 125IUDR-labeled 870127T HLC cells in nude mice were evaluated. After 870127T HLC cells were plated and 125IUDR was added to the dishes at levels ranging from 0.1 µCi/ml to 5.0 µCi/ml of media, the growth rate of the cells for 24h was similar to that of non-labeled cells. Nude mice were given intravenous injections of 125IUDR labeled 870127T HLC cells and killed at various intervals ranging from 5 min to 24 h after injection. Organs were collected, processed, and monitored. The lung contained most of the tumor cells at all intervals and the number of tumor cells in the lung decreased gradually post-injection. The tumor cells died rapidly, and only about 1.5% of all cell survived after 24 h post-injection. This study confirmed that very few surviving tumor cells are needed to cause metastasis.  相似文献   
17.
PURPOSE: The prognosis of metastatic renal cell carcinoma is extremely poor. In this type of metastatic tumor cytoreductive surgery of the primary tumor is often performed to confirm the histological type or improve the response to immunotherapy with agents such as interferon or interleukin-2. However, the timing and impact of cytoreductive surgery on the success of immunotherapy require further study. We determined the type of metastatic renal cell carcinoma for which cytoreductive surgery is beneficial. MATERIALS AND METHODS: We retrospectively reviewed the records of 58 patients in whom metastatic renal cell carcinoma was diagnosed at our hospital between 1986 and 1997. Three patients were excluded from study because they were judged to be poor candidates for surgery due to poor performance status. Of the remaining 55 patients 34 consented to cytoreductive surgery of the primary tumor and 21 did not. All except 1 patient were treated with interferon therapy. We evaluated the association of pretreatment serum C-reactive protein and the effect of surgery. RESULTS: We noted no significant difference in age at diagnosis, pretreatment serum immunosuppressive acidic protein, site of metastasis or performance status in 34 patients who underwent cytoreductive surgery and 21 who did not. Of the 21 patients in whom pretreatment serum C-reactive protein was within normal limits (less than 1.0 ng./ml.) no significant difference in disease specific survival was observed in those who did and did not undergo surgery (p = 0.4133). On the other hand, of 34 patients in whom pretreatment serum C-reactive protein was elevated (1.0 ng./ml. or greater) the prognosis was significantly better in those who did versus those who did not undergo surgery (p = 0.0054). Particularly the prognosis in patients in whom postoperative nadir C-reactive protein decreased to within normal limits was markedly better than in those in whom it remained elevated (p = 0.0025). CONCLUSIONS: Our study suggests that cytoreductive surgery is beneficial to patients in whom pretreatment serum C-reactive protein is elevated. Particularly, those in whom serum C-reactive protein decreases to within normal limits may expect longer survival when surgery is combined with postoperative immunotherapy. Currently to our knowledge the prognostic factor that predicts postoperative nadir C-reactive protein has not been identified, indicating that cytoreductive surgery of the primary tumor should be performed in patients with elevated pretreatment C-reactive protein and as performance status permits.  相似文献   
18.
Two men, aged 21 and 50 years, were seen with ossification of the patellar tendon after injury to the knee in adolescence. They complained of pain and had patella alta. Large bony masses were excised from below the affected patellae. The patellar tendon was then reconstructed using a Leeds-Keio ligament. The results at six and ten years, respectively, were good, with neither patient having pain or an extension lag.  相似文献   
19.
20.
We investigated the type of T cell response involved in Meth A tumor rejection in primary immune and hyperimmune syngeneic mice. It was found that a CD4+ T cell-mediated delayed-type hypersensitivity (DTH) response activating non-specific killer cells such as macrophages, NK and LAK cells, without a specific CD8+ cytotoxic T lymphocyte (CTL) response, was the major immune response leading to Meth A tumor rejection in primary immune mice. In contrast, the specific CD8+ CTL response was the major response leading to the tumor rejection, in addition to CD4+ T cell-mediated DTH response, in hyperimmune mice. Analysis of CD4+ T cell clones established from primary immune and hyperimmune spleen cells indicated that a CD4+ T cell clone (C9) of primary immune mice (although only one clone was established) was of Th1 type, and induced cytotoxicity in accessory cells by classic DTH in vitro. Eight CD4+ T cell clones were established from hyperimmune spleen cells. Six out of the eight clones were of the Th2 type and two were Th0-like. However, no Th1-type CD4+ T cell clone was established from hyperimmune spleen cells. All of these CD4+ T cell clones, even the Th2-type clones, were capable of inducing cytotoxicity in vitro in T cell-depleted accessory cells, as in an in vitro DTH response. We postulate on the basis of these results that the T cell response leading to Meth A tumor rejection in vivo sequentially changed from a CD4+ T cell-mediated classic DTH response to a CD8+ CTL response, in addition to a cellular response mediated probably by Th2-type cells, during the process of repeated immunization.  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