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   8102篇
  免费   785篇
  国内免费   410篇
耳鼻咽喉   80篇
儿科学   98篇
妇产科学   110篇
基础医学   957篇
口腔科学   211篇
临床医学   968篇
内科学   1368篇
皮肤病学   277篇
神经病学   518篇
特种医学   236篇
外国民族医学   3篇
外科学   925篇
综合类   1035篇
现状与发展   1篇
一般理论   1篇
预防医学   524篇
眼科学   168篇
药学   833篇
  4篇
中国医学   341篇
肿瘤学   639篇
  2023年   102篇
  2022年   122篇
  2021年   311篇
  2020年   241篇
  2019年   278篇
  2018年   313篇
  2017年   261篇
  2016年   263篇
  2015年   363篇
  2014年   404篇
  2013年   440篇
  2012年   549篇
  2011年   610篇
  2010年   376篇
  2009年   283篇
  2008年   438篇
  2007年   470篇
  2006年   487篇
  2005年   441篇
  2004年   281篇
  2003年   298篇
  2002年   214篇
  2001年   180篇
  2000年   177篇
  1999年   195篇
  1998年   144篇
  1997年   131篇
  1996年   89篇
  1995年   84篇
  1994年   68篇
  1993年   39篇
  1992年   99篇
  1991年   61篇
  1990年   74篇
  1989年   35篇
  1988年   53篇
  1987年   49篇
  1986年   39篇
  1985年   35篇
  1984年   20篇
  1983年   17篇
  1982年   13篇
  1981年   20篇
  1980年   12篇
  1979年   21篇
  1977年   8篇
  1976年   15篇
  1973年   9篇
  1969年   7篇
  1965年   6篇
排序方式: 共有9297条查询结果,搜索用时 31 毫秒
1.
Background: Considering the poor prognosis of non-small cell lung cancer (NSCLC), the objective of this study was to examine the potential of plasma-derived vesicles as a source of lung cancer-specific proteins. Extracellular vesicle (EV) cargos are specific to the source cells, hence they have the potential of being a source of cancer-specific proteins.  Methods: The proteins differently expressed in cancer were determined and derived from EVs isolated from the plasma of NSCLC patients at the National Lung Hospital. To this end, purification was done using gel filtration chromatography and ultracentrifugation. In addition, nano liquid chromatography mass spectrometry (LC–MS/MS) was used for analyzing. Results: Fifty-seven EV-derived proteins related to NSCLC were highlighted in this research. Some of them have not been addressed before, such as EEF1A1 (elongation factor 1-α1), KPNB1 (Importin subunit beta 1), SRC (proto-oncogene tyrosine-protein kinase) and ACTC1 (actin, alpha cardiac muscle 1). This list was further confirmed through a comparison with ExoCarta and Vesiclepedia. Conclusion: This study is the first work to show the involvement of several novel proteins of small EV (EEF1A1, KPNB1, SRC, and ACTC1) in the progression of NSCLC. The results suggested that they could serve as novel biomarkers for non-small cell lung cancer in the future.  相似文献   
2.
3.
4.
目的 通过网络药理学的方法进行预测,再深一步进行动物实验验证来研究柴胡疏肝散治疗CAG的作用机制。方法 首先在TCMSP数据库中检索柴胡疏肝散的所有活性成分与药物靶点;通过收集PharmGkb、OMIM、GeneCards和DrugBank数据库中收录的慢性萎缩性胃炎的相关靶点。将药物靶点与疾病靶点进行映射筛选出交集靶点,将得到的交集靶点构建PPI网络与活性成分-共同靶点网络,并对其进行GO和KEGG富集分析。最后利用Vina软件进行分子对接实验验证,并通过免疫印迹法验证柴胡疏肝散对两种受体蛋白EGFR和STAT1的影响。结果 最终筛选得到柴胡疏肝散活性成分104个,潜在靶点238个,与慢性萎缩性胃炎的交集靶点52个;GO与KEGG富集分析分别得到2166条目和148条目,主要涉及到JAK-STAT信号通路、TNF信号通路、HIF-1信号通路等;分子对接结果显示EGFR、STAT1两个靶点能够与核心活性成分能够自发结合成较为稳定的构像;免疫印迹法实验证明柴胡疏肝散能够降低大鼠胃黏膜组织EGFR和STAT1蛋白表达。结论 通过网络药理学和实验验证,发现柴胡疏肝散可能通过调节EGFR和STAT1蛋白表达来共同调控胃黏膜细胞增殖与凋亡,进而发挥着治疗慢性萎缩性胃炎的效果,为深入进行柴胡疏肝散治疗慢性萎缩性胃炎的作用机制研究提供新思路和新方法。  相似文献   
5.
6.
7.

Introduction

The aim of this study was to determine whether complications following mastectomy with immediate breast reconstruction (IBR) were associated with breast cancer recurrence.

Methods

A retrospective review was performed of women diagnosed with stage I-III breast cancer who underwent mastectomy with IBR between 2005 and 2010. Patient demographics, tumor data, surgical wound complications, treatment details and timing were recorded and analyzed.

Results

We identified 458 women with a median follow up time of 7.6 years. A total of 22% of patients experienced IBR complications. There was a delay in initiation of adjuvant therapy in patients who had a complication (52 vs 41 days, p?<?0.001). There was no significant difference in recurrences between groups with and without complications (p?=?0.65).

Conclusions

In breast cancer patients who undergo mastectomy with IBR, wound complications delayed initiation of adjuvant systemic therapy, but were not associated with an increased risk of cancer recurrence.  相似文献   
8.
9.
Systemic sclerosis (SSc) is an autoimmune disease mainly characterized by persistent inflammation and fibrosis. The receptor tyrosine kinase (RTK) signal pathway plays an important role in the process of SSc, and Grb2‐associated binding protein (GAB) is crucial in activating RTK signalling. A previous study found elevated levels of GAB1 in bleomycin (BLM)‐induced fibrotic lungs, but the effects of GAB1 in SSc remain unclear. Our aim was to investigate whether GAB1 was dysregulated and its potential role in SSc. Compared with healthy donors, we found GAB1 expression was 1.6‐fold higher in peripheral blood mononuclear cells (PBMC), 2.5‐fold higher in CD4 + T cells, and 2‐fold higher in skin from of SSc patients (P < .01). At the same time, the levels of type one collagen (COLI) were also significantly increased (1.8‐fold higher) in SSc skin. Additionally, BLM‐induced SSc mice showed mRNA levels of Gab1 2‐fold higher than saline‐treated controls, and Gab1 expression correlated positively with collagen content. A further in vitro study showed silencing of GAB1 suppressed inflammatory gene expression in TNF‐α induced fibroblasts. Additionally, GAB1 deficiency prominently inhibited cell proliferation and reduced COLI protein levels in TGF‐β induced fibroblasts. Taken together, these data suggest that GAB1 has a relatively high expression rate in SSc, and knockdown of GAB1 may attenuate SSc by stimulating inflammatory and fibrotic processes.  相似文献   
10.
The analysis of quality of life (QoL) data can be challenging due to the skewness of responses and the presence of missing data. In this paper, we propose a new weighted quantile regression method for estimating the conditional quantiles of QoL data with responses missing at random. The proposed method makes use of the correlation information within the same subject from an auxiliary mean regression model to enhance the estimation efficiency and takes into account of missing data mechanism. The asymptotic properties of the proposed estimator have been studied and simulations are also conducted to evaluate the performance of the proposed estimator. The proposed method has also been applied to the analysis of the QoL data from a clinical trial on early breast cancer, which motivated this study.  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