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   217548篇
  免费   3595篇
  国内免费   259篇
耳鼻咽喉   1493篇
儿科学   7856篇
妇产科学   4155篇
基础医学   22077篇
口腔科学   2457篇
临床医学   16625篇
内科学   40012篇
皮肤病学   1528篇
神经病学   21004篇
特种医学   10228篇
外科学   34283篇
综合类   2477篇
一般理论   19篇
预防医学   21180篇
眼科学   3460篇
药学   12074篇
  1篇
中国医学   708篇
肿瘤学   19765篇
  2024年   70篇
  2023年   522篇
  2022年   999篇
  2021年   1804篇
  2020年   1065篇
  2019年   1497篇
  2018年   23333篇
  2017年   18326篇
  2016年   20583篇
  2015年   2405篇
  2014年   2881篇
  2013年   3353篇
  2012年   10712篇
  2011年   24616篇
  2010年   20576篇
  2009年   13186篇
  2008年   22341篇
  2007年   24418篇
  2006年   3155篇
  2005年   4741篇
  2004年   5509篇
  2003年   6229篇
  2002年   4167篇
  2001年   482篇
  2000年   549篇
  1999年   384篇
  1998年   493篇
  1997年   417篇
  1996年   288篇
  1995年   279篇
  1994年   248篇
  1993年   177篇
  1992年   121篇
  1991年   157篇
  1990年   182篇
  1989年   114篇
  1988年   89篇
  1987年   71篇
  1986年   56篇
  1985年   59篇
  1984年   56篇
  1983年   39篇
  1982年   63篇
  1980年   60篇
  1969年   24篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
991.
992.
cDNA arrays and proteomic analyses have allowed the rapid identification of specific genes and proteins implicated in multiple tumor types. These molecules must then be validated as clinically relevant prognostic and predictive markers, and this translational research is best conducted in the context of clinical trials. Outcomes data and clinical specimens collected in the ‘Arimidex’, Tamoxifen, Alone or in Combination (ATAC) study, for example, can now be used to compare the expression of biomarkers with clinical outcomes. In this study, adjuvant tamoxifen and anastrozole (‘Arimidex’) were compared alone and in combination in more than 9000 women with breast cancer. Anastrozole was found to be superior to tamoxifen in terms of disease-free survival, time to recurrence, and reduction in the incidence of contralateral tumors. Importantly, tissue specimens from surgical excision, local relapse, and contralateral breast cancer were collected and paraffin-embedded for storage. In the TA01 (TransATAC) program, these specimens will be studied (after obtaining patient consent) using tissue microarrays; tissue biopsy cores 0.6 mm in diameter will be removed from donor blocks and placed on recipient blocks, which will be sectioned to allow the simultaneous analysis of the same samples for multiple biomarkers. These analyses can help determine differential benefits of treatment with anastrozole or tamoxifen, depending on the expression of particular biomarkers in tumor cells. This research also should clarify de novo and acquired resistance mechanisms, and the validation of relevant molecular pathways could guide the development of new drugs. Ultimately, the TA01 program has the potential to favorably impact treatment choices for breast cancer. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
993.
PURPOSE: The purpose of this research was to assess in vivo by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) the antiangiogenic effect of SU6668, an oral, small molecule inhibitor of the angiogenic receptor tyrosine kinases vascular endothelial growth factor receptor 2 (Flk-1/KDR), platelet-derived growth factor receptor, and fibroblast growth factor receptor 1. EXPERIMENTAL DESIGN: A s.c. tumor model of HT29 human colon carcinoma in athymic mice was used. DCE-MRI with a macromolecular contrast agent was used to measure transendothelial permeability and fractional plasma volume, accepted surrogate markers of tumor angiogenesis. CD31 immunohistochemical staining was used for assessing microvessels density and vessels area. Experiments were performed after 24 h, and 3, 7, and 14 days of treatment. RESULTS: DCE-MRI clearly detected the early effect (after 24 h of treatment) of SU6668 on tumor vasculature as a 51% and 26% decrease in the average vessel permeability measured in the tumor rim and core (respectively). A substantial decrease was also observed in average fractional plasma volume in the rim (59%) and core (35%) of the tumor. Histological results confirmed magnetic resonance imaging findings. After 3, 7, and 14 days of treatment, postcontrast magnetic resonant images presented a thin strip of strongly enhanced tissue at the tumor periphery; histology examination showed that this hyperenhanced ring corresponded to strongly vascularized tissue adjacent but external to the tumor. Histology also revealed a strong decrease in the thickness of peripheral viable tissue, with a greatly reduced vessel count. SU6668 greatly inhibited tumor growth, with 60% inhibition at 14 days of treatment. CONCLUSIONS: DCE-MRI detected in vivo the antiangiogenic efficacy of SU6668.  相似文献   
994.
995.
Background Duodenogastric reflux is known to cause an increased frequency of cancer in the glandular portion of the stomach in rats. Furthermore, it is debated whether inhibition of gastric acid secretion may promote gastric carcinogenesis. In the present study we examined the combined effect of gastroduodenal reflux and acid inhibition with respect to the development of gastric carcinoma in the rat.Methods Following the construction of a gastrojejunostomy in male Wistar rats, half of them were given the proton pump inhibitor lanzoprazole for 1 year. The rats were then killed and the pH in the stomach and gastrin in blood were measured. The stomach was examined macroscopically as well as histologically.Results Gastrin levels at autopsy were significantly increased in treated rats compared to the control group, confirming an effect of lanzoprazole on gastric acid secretion. Body weight was significantly reduced in the treated rats. Thirty of 79 rats developed gastric cancer, and they were all adenocarcinomas of the Lauren intestinal type. Gastric cancers occurred significantly more often in lanzoprazole-treated rats (50%) compared with controls (27%).Conclusion Lanzoprazole given orally enhances the carcinogenic effect of duodenogastric reflux in rats.  相似文献   
996.
Background Despite curative resection, 50%–90% of gastric cancer patients die of disease relapse. Although some clinical trials have indicated that chemotherapy and immunochemotherapy may be effective modalities, more recent studies have not been able to define the standard treatment for advanced gastric cancer. The present study evaluated the effect of adjuvant immunochemotherapy with the use of BCG (bacille Calmette-Guérin) and FAM (5-fluorouracil, adriamycin, mitomycin C) chemotherapy on the survival of patients with locally advanced resectable gastric cancer.Methods A total of 156 patients with stage III or IV gastric cancer who had undergone curative resection were randomly assigned to three treatment groups: BCG + FAM (immunochemotherapy), FAM (chemotherapy), and control (surgery only). Treatment was continued for 2 years or until death. Further postsurgical follow up was carried on for up to 10 years.Results Overall 10-year survival was 47.1% for the immunochemotherapy group (P < 0.037 vs FAM and P < 0.0006 vs control), 30% for the chemotherapy group (vs control, NS), and 15.2% for the control group. In patients with pT2/T3 primary tumors, 10-year survival was 55.3% for BCG + FAM vs 28.2% for FAM (P < 0.01) and 14.6% for the control group (P < 0.00018). BCG + FAM signifi-cantly improved the survival of patients with intestinal-type but not diffuse-type cancer. Immunochemotherapy was well tolerated.Conclusion This study, based on a limited number of patients, indicates that adjuvant immunochemotherapy (BCG + FAM) may prolong the survival of gastric cancer patients after curative gastrectomy; in particular, in patients with pT2/T3 tumors and intestinal-type primary tumors. There was no survival benefit from FAM adjuvant chemotherapy.  相似文献   
997.
998.
According to differentiation of symptoms and signs, prostatosis was divided into pattern of dampness and heat in the lower energizer, pattern of qi stagnation and blood stasis, pattern of deficiency and cold in the lower abdomen, and pattern of qi deficiency and kidney deficiency. Prostatosis were treated mainly by acupuncture, plus moxibustion and Chinese medicine, and the effect was good. Author: Zhao Chang-quan (1949-), male, junior consultant doctor Translator: Huang Guo-qi  相似文献   
999.
Yaoyangguan (GV 3), Shiqizhui (Ex-B 8) and Yanglingquan (GB 34) were selected as main points and a three-part needle insertion technique was used to treat 32 cases of lumbar intervertebral disc protrusion. The curative rate was 96.9%. Deep puncture is the key to the treatment. Author: Chen Feng(1962-), male, junior consultant doctor Translator: Wang Si-you  相似文献   
1000.
In the performance of rubbing manipulation, because of the fingers comparatively light vertical pressure and large-range circular movement, the palm and fingers cannot adhere to the patient's skin, and the relative friction movement.  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