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   2135篇
  免费   112篇
  国内免费   6篇
耳鼻咽喉   20篇
儿科学   33篇
妇产科学   99篇
基础医学   168篇
口腔科学   32篇
临床医学   191篇
内科学   502篇
皮肤病学   8篇
神经病学   246篇
特种医学   71篇
外国民族医学   1篇
外科学   285篇
综合类   6篇
预防医学   120篇
眼科学   15篇
药学   204篇
中国医学   4篇
肿瘤学   248篇
  2023年   13篇
  2022年   39篇
  2021年   34篇
  2020年   27篇
  2019年   35篇
  2018年   41篇
  2017年   31篇
  2016年   40篇
  2015年   56篇
  2014年   69篇
  2013年   84篇
  2012年   151篇
  2011年   148篇
  2010年   81篇
  2009年   85篇
  2008年   154篇
  2007年   155篇
  2006年   143篇
  2005年   147篇
  2004年   145篇
  2003年   137篇
  2002年   100篇
  2001年   24篇
  2000年   32篇
  1999年   15篇
  1998年   25篇
  1997年   26篇
  1996年   17篇
  1995年   12篇
  1994年   12篇
  1993年   18篇
  1992年   7篇
  1991年   8篇
  1990年   13篇
  1989年   12篇
  1988年   9篇
  1987年   16篇
  1986年   11篇
  1985年   5篇
  1984年   13篇
  1982年   7篇
  1981年   5篇
  1980年   8篇
  1979年   3篇
  1978年   7篇
  1977年   3篇
  1976年   3篇
  1973年   3篇
  1971年   5篇
  1933年   2篇
排序方式: 共有2253条查询结果,搜索用时 0 毫秒
101.
There are cases in which resection of cervico-mediastinal goitres requires additional thoracic access as an adjunct to standard transverse cervicotomy, and typically this takes the form of sternotomy or thoracotomy. The authors propose transclavicular access as an alternative to thoracotomy or sternotomy access for the removal of such goitres. This technical variant is performed by means of resection of the middle third of the clavicle and extraperiosteal disarticulation. They report a case of cervicomediastinal or "plunged" goitre associated with mediastinal metastasis from a follicular thyroid carcinoma in a 77-year-old woman, in whom this technical variant was used. They conclude by stressing the greater effectiveness, ease of execution and relatively limited "aggressiveness" of the technique in comparison with other ways of reaching the mediastinum. The variant proves effective in solving a number of technical, functional and aesthetic problems.  相似文献   
102.
Endometrial carcinoma (EC) is the second most common tumor in hereditary nonpolyposis colorectal cancer (HNPCC), with an incidence rate of 60% by the age of 70 in mutation carriers. The International Collaborative Group on HNPCC revised the Amsterdam criteria and proposed a new, wider definition including extracolonic cancers. The aim of our study was to evaluate the accuracy of a new definition called Amsterdam criteria II. We updated, reclassified and compared the pedigrees of 29 women, already reported as being affected by EC and having a colorectal cancer familial background, according to the two clinical diagnostic criteria for HNPCC (Amsterdam criteria I, ACI, and Amsterdam criteria II, ACII) after two periods of observation (1990-1995 and 1995-2000). According to ACII the frequency of HNPCC in the population under study increased from 0.9% to 3.7% in the period 1990-1995 and from 3.2% to 3.7% in the period 1995-2000. ACII allowed early detection of HNPCC families and thus made it possible to provide them with a suitable surveillance program and genetic testing.  相似文献   
103.
Seventeen patients affected by acute myeloid leukemia (AML) with t(8;21) were prospectively programmed to receive three courses of high-dose cytarabine (HDARA-C) as post-remission therapy. The median age was 39 years and in all cases t(8;21) was the only karyotypic abnormality. Complete remission (CR) was achieved in 14 out of 17 cases (82%) and, after first consolidation with NOVIA regimen (intermediate dose ARA-C plus mitoxantrone), all patients received the three planned courses of HDARA-C (3g/m(2) q12h on days 1, 3, 5). There were two documented infections, while all patients experienced fever of unknown origin (FUO). Nonhematological toxicity was mild. Thirteen out of 14 patients are in continuous CR after a median follow-up of 44 months. One patient relapsed at 16 months and, following CR2 achievement, underwent allogeneic transplantation; he died 3 months later while in CR from acute graft versus host disease (GVHD). Survival at 5 years is projected at 79%. Our data confirm the efficacy of repeated courses of HDARAC for patients with t(8;21) AML.  相似文献   
104.
Antibodies to heparan sulfate (HS) have previously been found in association with peripheral neuropathy. We tested sera from patients with neuropathies and with other neurological diseases for antibodies to HS using an avidin-biotin enzyme-linked immunosorbent assay (ELISA) system. Increased titers of anti-HS antibodies were found in 3.4% of patients with neuropathy, and in 3% of patients with other neurological diseases. In all cases, however, an inflammatory disease was present, including chronic inflammatory neuropathy, cerebral vasculitis, or multiple sclerosis. Antibodies to HS appear not to be specific for neuropathy, as they occur in several inflammatory diseases. They might contribute to the associated breakdown of the blood-brain or blood-nerve barrier.  相似文献   
105.
PURPOSE: To assess the value of changes in the expression of topoisomerase IIalpha (TopoII) and the proto-oncogene erbB-2 (HER-2) as predictors of relapse-free survival in women with operable breast cancer treated with anthracycline-based neoadjuvant chemotherapy. PATIENTS AND METHODS: Seventy-seven patients with primary breast cancer who had undergone neoadjuvant anthracycline-based chemotherapy were included in the present study. TopoII and HER-2 were measured by immunohistochemistry in prechemotherapy and postchemotherapy (at the time of surgery) tumor specimens, and the value of their changes as predictors of relapse-free survival were evaluated by Kaplan-Meier and Cox proportional hazard regression analyses. RESULTS: Neoadjuvant chemotherapy resulted in a significant reduction in the percentage of cells expressing TopoII (P < 0.0001). No significant change was observed for HER-2. TopoII and HER-2 expression before chemotherapy predicted tumor response to treatment. Changes in TopoII expression after chemotherapy were strongly associated with a poor relapse-free survival (P < 0.0001) in a Cox multivariate analysis adjusted for other clinicopathologic prognostic factors. CONCLUSION: Changes in TopoII expression after anthracycline-based neoadjuvant chemotherapy is an independent predictor of a poor relapse-free survival in patients with breast cancer. Tumor cells displaying an increased TopoII expression after treatment may be responsible for relapses, and may, therefore, define a group of patients with anthracycline-resistant breast cancer.  相似文献   
106.
107.
108.
109.
The multi-drug combination of oxaliplatin (OXA), 5-Fluorouracil (5-FU) and leucovorin (LF) is currently considered as the gold standard treatment for metastatic colorectal carcinoma. In previous studies, we have studied a chemotherapy regimen containing gemcitabine (GEM), OXA, LF, and 5-FU (named GOLF regimen) that has shown a good safety profile and highly significant anti-tumor activity. In the present study, we have investigated on the anti-tumour mechanisms of GOLF in human colon cancer HT-29 and WiDr cell lines. We have found that GOLF induced growth inhibition that was largely caused by apoptosis differently from other combinations. Moreover, the different drugs composing GOLF were highly synergistic in inducing growth inhibition. Apoptosis induced by GOLF combination was paralleled by PARP cleavage and caspase 9 and 3 activation that were not recorded in the other combinations. An about 85% decrease of the activity of Erk and Akt was found in GOLF-treated cells. These effects were likely due to decreased expression of the upstream activator Raf-1 and of Akt itself, respectively. The intracellular levels of these signalling components can be post-translationally regulated by ubiquitin-dependent degradation through proteasome. Therefore, we have evaluated the expression of some chaperone components and we have found that GOLF did not affect the expression of both heat shock protein (HSP) 90 and 27 but induced an about 90% increase of HSP70 levels suggesting the inactivation of the multi-chaperone complex. Moreover, an about 4-fold increase of the ubiquitination of Raf-1 was also found and the addition for 12 h of 10 microM proteasome inhibitor lactacystin caused an accumulation of the ubiquitinated isoforms of Raf-1. In conclusions, GOLF was a combination highly synergistic in inducing both growth inhibition and apoptosis of colon cancer cells. These effects likely occurred through the disruption of critical survival pathways and the inactivation of multi-chaperone complex.  相似文献   
110.
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