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   7742篇
  免费   408篇
  国内免费   37篇
耳鼻咽喉   32篇
儿科学   164篇
妇产科学   67篇
基础医学   1334篇
口腔科学   271篇
临床医学   525篇
内科学   1619篇
皮肤病学   238篇
神经病学   877篇
特种医学   478篇
外科学   1086篇
综合类   53篇
一般理论   2篇
预防医学   269篇
眼科学   100篇
药学   565篇
中国医学   11篇
肿瘤学   496篇
  2022年   37篇
  2021年   67篇
  2020年   74篇
  2019年   93篇
  2018年   114篇
  2017年   100篇
  2016年   112篇
  2015年   160篇
  2014年   246篇
  2013年   306篇
  2012年   401篇
  2011年   426篇
  2010年   306篇
  2009年   289篇
  2008年   433篇
  2007年   483篇
  2006年   485篇
  2005年   500篇
  2004年   475篇
  2003年   493篇
  2002年   499篇
  2001年   106篇
  2000年   103篇
  1999年   142篇
  1998年   132篇
  1997年   109篇
  1996年   101篇
  1995年   88篇
  1994年   82篇
  1993年   69篇
  1992年   65篇
  1991年   64篇
  1990年   53篇
  1989年   54篇
  1988年   43篇
  1987年   59篇
  1986年   33篇
  1985年   49篇
  1984年   30篇
  1983年   33篇
  1982年   41篇
  1981年   36篇
  1980年   37篇
  1978年   38篇
  1977年   32篇
  1976年   40篇
  1975年   28篇
  1974年   40篇
  1973年   35篇
  1970年   33篇
排序方式: 共有8187条查询结果,搜索用时 193 毫秒
51.
In the Surgical Department of the University of Erlangen, 307 reconstructions in all areas of the arterial tree were performed with PTFE (GORE-TEX®) grafts, of which 188 were performed in the femoral-popliteal and femoral-crural areas. Femoral-popliteal bypass grafts above the knee joint remained patent in 93% of the patients during an average follow-up time of 6.7 months. Below the knee joint, the patency rate was 85% during an average follow-up time of 5.6 months. In the proximal aorta, aorta-renal, and aorta-femoral areas, long-term results with the PTFE graft have been excellent.  相似文献   
52.

Proceedings

Fourth swiss EEG-EP mapping meeting  相似文献   
53.
54.
BACKGROUND: The role of Daxx, in particular its ability to promote or hinder apoptosis, still remains controversial. In order to elucidate the functional relevance of Daxx in the extrinsic signaling of malignant lymphocytes Jurkat T-cells were stably transfected with a Daxx-expressing vector or with the respective Daxx-negative control vector. RESULTS: Assessing first the impact of Daxx expression on the rate of proliferation we demonstrate that overexpression of Daxx alone is not sufficient to alter proliferation in neoplastic lymphocytes. Nevertheless, expression of Daxx down-regulates anti-apoptotic Bcl-2 and up-regulates pro-apoptotic BID. In addition, Daxx-overexpressing Jurkat cells exhibit a decreased expression of the pro-caspase-8, -10, -9 and -3 and a concomitant increase of the inhibitors of apoptosis proteins survivin, XIAP, cIAP-1 and -2. We further demonstrate, that upon incubation with various chemotherapeutic agents these Daxx-induced molecular alterations sensitize Jurkat T-cells to the apoptosis-inducing effects of specific chemotherapeutic agents. CONCLUSIONS: We here outline the molecular changes elicited by Daxx on major components of the apoptotic cascade of malignant lymphocytes and demonstrate the capacity of Daxx to sensitize these cells to the apoptosis-inducing effect of various chemotherapeutic agents.  相似文献   
55.
56.
PURPOSE: Bone marrow neoangiogenesis plays an important pathogenetic and possible prognostic role in acute myeloid leukemia (AML). Members of the vascular endothelial growth factor (VEGF) and angiopoietin family represent the most specific inducers of angiogenesis secreted by AML blasts. We therefore correlated expression of angiogenic factors with clinical variables. PATIENTS AND METHODS: We investigated the expression of VEGF-A, VEGF-C, angiopoietin-1 (Ang1), angiopoietin-2 (Ang2), and the receptor Tie2 by quantitative polymerase chain reaction in a cohort of 90 patients younger than 61 years with de novo AML entered into the German AML Süddeutsche H?moblastose Gruppe Hannover 95 trial. Uni- and multivariate analyses were performed using clinical and gene expression variables. RESULTS: Univariate analysis of overall survival indicated the following variables as prognostic factors: good response on a day-15 bone marrow examination after initiation of induction chemotherapy, karyotype, and high Ang2 expression. In multivariate analysis, only bad response and log Ang2 expression remained of statistical significance, with a hazard ratio of 3.51 (95% CI, 1.91 to 6.47) and 0.75 (95% CI, 0.61 to 0.91), respectively. Subgroup analysis suggested that the prognostic impact of Ang2 expression was especially evident in cohorts with low VEGF-C and Ang1 mRNA levels. CONCLUSION: These results show that expression of Ang2 represents an independent prognostic factor in AML. Additional research into interactions of angiogenic cytokines in the pathogenesis of bone marrow angiogenesis in AML is warranted.  相似文献   
57.
INTRODUCTION: Some 5-10% of all cases of breast cancer and ovarian cancer have a hereditary genesis. In the setting of an interdisciplinary cancer genetics clinic, a study of the age at which patients first take advantage of early cancer detection (ECD) facilities was conducted in order to assess the influence of familial risk on health issues. METHODS: The study included 556 women who fulfilled the inclusion criteria (IC) for genetic analysis of the BRCA1 and BRCA2 genes, as well as 205 who did not meet these criteria but attended the primary consultation. RESULTS: Consulters who met the inclusion criteria took advantage of nearly all methods of ECD at an earlier time than women who did not. A comparison of consulters with or without breast cancer showed that those without breast cancer participated in all methods of ECD at an earlier time. CONCLUSION: Methods of improving and increasing participation in ECD facilities, and of encouraging women who are at risk to start on such programs at a younger age, need to be discussed. In this study, familial risk already resulted in a younger age of uptake of ECD facilities.  相似文献   
58.
The analysis of circulating tumor DNA (ctDNA) is at the threshold of implementation into standard care for colorectal cancer (CRC) patients. However, data about the clinical utility of liquid profiling (LP), its acceptance by clinicians, and its integration into clinical workflows in real‐world settings remain limited. Here, LP tests requested as part of routine care since 2016 were retrospectively evaluated. Results show restrained request behavior that improved moderately over time, as well as reliable diagnostic performance comparable to translational studies, with an overall agreement of 91.7%. Extremely low ctDNA levels at < 0.1% in over 20% of cases, a high frequency of concomitant driver mutations (in up to 14% of cases), and ctDNA levels reflecting the clinical course of disease were revealed. However, certain limitations hampering successful translation of ctDNA into clinical practice were uncovered, including the lack of clinically relevant ctDNA thresholds, appropriate time points of LP requests, and integrative evaluation of ctDNA, imaging, and clinical findings. In conclusion, these results highlight the potential clinical value of LP for CRC patient management and demonstrate issues that need to be addressed for successful long‐term implementation in clinical workflows.  相似文献   
59.
60.
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