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   287846篇
  免费   27288篇
  国内免费   22437篇
耳鼻咽喉   2214篇
儿科学   2559篇
妇产科学   3105篇
基础医学   34613篇
口腔科学   4789篇
临床医学   40495篇
内科学   41378篇
皮肤病学   2670篇
神经病学   15752篇
特种医学   10558篇
外国民族医学   200篇
外科学   27445篇
综合类   50599篇
现状与发展   75篇
一般理论   28篇
预防医学   18344篇
眼科学   8583篇
药学   31292篇
  320篇
中国医学   17439篇
肿瘤学   25113篇
  2024年   973篇
  2023年   4611篇
  2022年   11974篇
  2021年   14848篇
  2020年   11396篇
  2019年   9796篇
  2018年   10270篇
  2017年   9126篇
  2016年   8652篇
  2015年   13023篇
  2014年   16101篇
  2013年   13778篇
  2012年   20340篇
  2011年   23213篇
  2010年   14473篇
  2009年   11335篇
  2008年   14696篇
  2007年   14877篇
  2006年   15038篇
  2005年   14978篇
  2004年   9785篇
  2003年   9609篇
  2002年   8261篇
  2001年   7239篇
  2000年   7284篇
  1999年   7617篇
  1998年   4936篇
  1997年   5012篇
  1996年   3845篇
  1995年   3640篇
  1994年   3023篇
  1993年   2031篇
  1992年   2296篇
  1991年   1917篇
  1990年   1625篇
  1989年   1374篇
  1988年   1162篇
  1987年   1020篇
  1986年   779篇
  1985年   619篇
  1984年   353篇
  1983年   220篇
  1982年   120篇
  1981年   129篇
  1980年   83篇
  1979年   92篇
  1965年   1篇
  1962年   1篇
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
81.
PurposeWe previously demonstrated that the functional inactivation of DAL-1 and TOB1 promotes an aggressive phenotype in gastric cancer cells, but the links between both genes and the survival of patients with gastric cancer are unknown. Here, we investigated the correlations of the expression levels of DAL-1 and TOB1 with the progression of gastric cancer.MethodsA total of 270 patients who underwent resectable gastrectomy were included. The expression of DAL-1 and TOB1 was detected by immunohistochemistry.ResultsLow expression of DAL-1 in cancer tissue was significantly associated with tumor site (p < 0.05), histological grade (p < 0.01), depth of invasion (p < 0.05), lymph node metastasis status (p < 0.05), Lauren classification (p < 0.001), and clinical stage (p < 0.01). A lower level of TOB1 was observed in gastric cancer patients with diffuse type disease compared to patients with either intestinal or mixed type disease (p < 0.001). Additionally, Spearman’s correlation analysis revealed that decreased expression of DAL-1 was positively correlated with low TOB1 expression (r=0.304, p < 0.001). The survival analysis showed that low levels of DAL-1 and TOB1 were significantly associated with poor survival of gastric cancer patients (p <0.001 and p < 0.05, respectively).ConclusionThe downregulation of DAL-1 and TOB1 expression is associated with shorter survival of gastric cancer patients. Hence, DAL-1 and TOB1 may be considered potential novel markers for predicting the outcomes of patients with gastric cancer.  相似文献   
82.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

83.
84.
85.
86.
随着压力性损伤的研究重心逐渐向细胞水平转移,发现力学因素下细胞结构和功能改变在压力性损伤发展过程中起重要作用。综述力学因素下压力性损伤发生机制、影响因素、评估以及预防管理。旨在提高护理人员对压力性损伤更为深入地认知,从而推动压力性损伤研究多元化发展。  相似文献   
87.
随着腹腔镜肝切除技术的发展与推广,腹腔镜肝切除中的一些难点,如术中出血的控制、解剖性肝切除、巨大肝癌切除、腹腔镜下联合肝脏分割与门静脉支结扎的二步肝切除术(ALPPS)等方面均基本解决。术中超声与荧光染色技术也得到普及。本文就上述问题做一概述,并对腹腔镜肝切除未来发展提出思路,以进一步推动我国腹腔镜肝切除的技术进步。  相似文献   
88.
Two new 11-methoxyl substituted triterpenoids, named as mimengosides J (1) and K (2), along with seven known compounds, were isolated from the fruits of Buddleja lindleyana. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the new ones were evaluated for protective effects against damage of SH-SY5Y cells induced by 1-methyl-4-phenylpyridinium ion (MPP+) and the results indicated that those may be one of the candidate compositions of Buddleja lindleyana for the treatment of neurodegenerative disease.

  相似文献   

89.
90.
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