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   1821篇
  免费   72篇
  国内免费   8篇
耳鼻咽喉   12篇
儿科学   20篇
妇产科学   11篇
基础医学   185篇
口腔科学   54篇
临床医学   96篇
内科学   646篇
皮肤病学   69篇
神经病学   102篇
特种医学   74篇
外科学   200篇
综合类   6篇
预防医学   32篇
眼科学   22篇
药学   106篇
肿瘤学   266篇
  2023年   8篇
  2022年   17篇
  2021年   33篇
  2020年   10篇
  2019年   20篇
  2018年   21篇
  2017年   21篇
  2016年   41篇
  2015年   36篇
  2014年   42篇
  2013年   48篇
  2012年   80篇
  2011年   98篇
  2010年   44篇
  2009年   41篇
  2008年   75篇
  2007年   63篇
  2006年   93篇
  2005年   103篇
  2004年   101篇
  2003年   88篇
  2002年   97篇
  2001年   72篇
  2000年   63篇
  1999年   62篇
  1998年   30篇
  1997年   19篇
  1996年   23篇
  1995年   16篇
  1994年   9篇
  1993年   9篇
  1992年   49篇
  1991年   48篇
  1990年   45篇
  1989年   35篇
  1988年   28篇
  1987年   32篇
  1986年   19篇
  1985年   24篇
  1984年   9篇
  1983年   13篇
  1982年   8篇
  1981年   11篇
  1980年   6篇
  1979年   14篇
  1978年   7篇
  1977年   7篇
  1972年   7篇
  1971年   12篇
  1970年   7篇
排序方式: 共有1901条查询结果,搜索用时 15 毫秒
71.
Primary malignant melanoma (MM) of the mediastinum is rare, and there is a lack of consensus regarding the preferred treatment because non-cutaneous MM demonstrates an inferior response to systemic therapy. Herein, we describe the case of a 73-year-old man with MM of the anterior mediastinum with multiple liver metastases. Even though the size of lesions increased rapidly following diagnosis, nivolumab monotherapy caused remarkable tumor shrinkage. This is the first report of mediastinal MM showing a significant response to nivolumab. We, therefore, suggest that immunotherapy may be one of the treatment options for primary mediastinal MM.  相似文献   
72.
73.
74.
75.
Sixteen patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts between 1988 and 1989 at the Okayama University Hospital. A total 39 coronary grafts were performed, being an average of 2.4 grafts per patient. Each patient received bilateral ITA grafts, and in 5 patients an additional 7 grafts were constructed with 5 autologous veins and 2 gastroepiloic arteries. The right ITA was grafted as a free graft in 4 patients. The ITA graft patency rate was 96.8 per cent (31/32) at the time of hospital discharge. The postoperative morbidity included one reoperation for bleeding and one myocardial infarction. Coronary artery bypass grafting with bilateral ITA grafts can be safely performed and its application facilitates complete revascularization with arterial grafts.  相似文献   
76.
Purpose: Introduction of rituximab has largely improved the prognosis of patients with diffuse large B‐cell lymphoma(DLBCL). Such change in therapeutic outcome necessitates the identification of additional prognostic factors to conventional indexes that have been validated for CHOP without rituximab. Indoleamine 2,3‐dioxygenase (IDO) exerts intense immunomodulatory effects because of enzymatic activities that catalyze the breakdown of the essential amino acid L‐tryptophan. The activity of IDO can be estimated by measuring the serum concentration of L ‐kynurenine. Here, we investigated the role of L ‐kynurenine as a prognostic marker in R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) therapy. Experimental design: Data from 73 consecutive patients treated with eight cycles of R‐CHOP or R‐THP (tetrahydropyranyl adriamycin)‐COP between December 2002 and March 2007 were analyzed. L ‐kynurenine concentrations in serum samples obtained at admission were measured by high‐performance liquid chromatography. Results: The median serum L ‐kynurenine level was 1.575 μm (range 0.537–9.588). The complete response (CR) rates of patients with L ‐kynurenine <1.5 and ≥1.5 μm were 83% and 61%, respectively (P < 0.05). The three‐yr overall survival (OS) rates for patients with L ‐kynurenine <1.5 and ≥1.5 μm were 89% and 58%, respectively (P < 0.005). In addition, higher age, poor performance status, elevated serum lactate dehydrogenase, and unfavorable as well as revised International Prognosis Index were significantly worse factors for CR rate and OS. Multivariate analyses revealed only L ‐kynurenine as an independent prognostic factor for OS. Conclusions: Serum L ‐kynurenine might be a novel prognostic factor to determine the treatment outcome of DLBCL with the R‐CHOP regimen.  相似文献   
77.
78.
79.
BACKGROUND AND OBJECTIVE: To describe the biodistribution of a hydrophilic sensitizer, mono-L-aspartyl chlorin e6 (NPe6), in a primate model of choroidal neovascularization (CNV). MATERIALS AND METHODS: NPe6 (25 mg/kg) and indocyanine green (ICG, 15 mg/kg) were intravenously administered simultaneously in monkeys with laser-induced CNVs. Eyes were enucleated and examined by fluorescence microscopy immediately, 20 minutes, and 1, 4, and 24 hours after dye injection. RESULTS: Fluorescence peaked in retinal vessels immediately after dye administration; rapid washout began 1 hour postinjection. In contrast, experimental CNV demonstrated little fluorescence immediately after injection, with increased intensity at later time points. Peak dye fluorescence in CNV occurred 1 hour following dye injection. NPe6 fluorescence diminished rapidly and washed out completely by 24 hours. The dye accumulation and retention pattern of ICG dye resembled that of NPe6. CONCLUSIONS: This study demonstrated the selective accumulation of NPe6 photosensitizer and ICG dye within experimental CNV and rapid clearance from the circulation and retinochoroidal tissue.  相似文献   
80.
The receptor tyrosine kinase (RTK) insulin like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis plays an important role in the development of hepatocellular carcinoma (HCC). EGCG inhibits activation of the various types of RTKs and that this is associated with inhibition of multiple downstream signaling pathways. In this study we examined the effects of EGCG on activity of the IGF/IGF-1R axis in HepG2 human HCC cells which express constitutive activation of this axis. The level of phosphorylated (i.e. activated) form of the IGF-1R protein (p-IGF-1R) was increased in a series of human HCC cell lines when compared with the Hc normal human hepatocytes. EGCG preferentially inhibited growth of HepG2 cells when compared with Hc cells. Treatment of HepG2 cells with EGCG induced apoptosis and caused a decrease in the p-IGF-1R protein and its downstream signaling molecules including the p-ERK, p-Akt, p-Stat-3, and p-GSK-3β proteins, both in the absence or presence of ligand stimulation. EGCG also decreased the levels of both IGF-1 and IGF-2 proteins and mRNAs, but increased the levels of the IGFBP-3 protein. These findings suggest that EGCG can overcome the stimulatory effects of IGFs on the IGF-1R dependent signaling pathway, thus expanding the roles of EGCG as an inhibitor of critical RTKs involved in HCC cell proliferation. These results provide further evidence that EGCG may be useful in the chemoprevention or treatment of liver cancer.  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