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   34653篇
  免费   3140篇
  国内免费   2546篇
耳鼻咽喉   392篇
儿科学   397篇
妇产科学   367篇
基础医学   4067篇
口腔科学   581篇
临床医学   4795篇
内科学   4997篇
皮肤病学   376篇
神经病学   1998篇
特种医学   1272篇
外国民族医学   24篇
外科学   3205篇
综合类   6507篇
现状与发展   11篇
预防医学   2140篇
眼科学   1111篇
药学   3504篇
  26篇
中国医学   1886篇
肿瘤学   2683篇
  2024年   126篇
  2023年   678篇
  2022年   1597篇
  2021年   1841篇
  2020年   1427篇
  2019年   1227篇
  2018年   1254篇
  2017年   1195篇
  2016年   1027篇
  2015年   1583篇
  2014年   1947篇
  2013年   1698篇
  2012年   2661篇
  2011年   2754篇
  2010年   1631篇
  2009年   1309篇
  2008年   1574篇
  2007年   1665篇
  2006年   1684篇
  2005年   1705篇
  2004年   1065篇
  2003年   1020篇
  2002年   888篇
  2001年   788篇
  2000年   811篇
  1999年   941篇
  1998年   603篇
  1997年   668篇
  1996年   495篇
  1995年   416篇
  1994年   354篇
  1993年   207篇
  1992年   273篇
  1991年   238篇
  1990年   203篇
  1989年   179篇
  1988年   169篇
  1987年   133篇
  1986年   101篇
  1985年   78篇
  1984年   34篇
  1983年   20篇
  1982年   27篇
  1981年   15篇
  1980年   8篇
  1979年   9篇
  1965年   2篇
  1940年   3篇
  1935年   2篇
  1934年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
Yu  Hongjuan  Zeng  Xueyun  Sui  Mingjie  Liu  Rui  Tan  Rachel Lee-Yin  Yang  Jinjin  Huang  Weidong  Luo  Nan 《Quality of life research》2021,30(3):855-866
Quality of Life Research - This study aimed to compare the measurement properties of EQ-5D-3L(3L) and EQ-5D-5L(5L) in patients with acute myeloid leukemia (AML) in China. We consecutively recruited...  相似文献   
56.
Following crush injury to rat sciatic nerves, a crude fraction of the 150,000 g supernatant can post-translationally incorporate [3H]Arg and [3H]Lys into endogenous proteins in amounts approximately 10 times uninjured control nerves. These increases occur in the proximal nerve stump within 2 h of injury and 2 weeks later in a distal segment of nerve containing the tips of the regenerating axons. In the present experiments, the endogenous nerve proteins modified by Arg or Lys in these nerve segments have been identified using two-dimensional polyacrylamide gel electrophoresis. The fraction used to assay for protein modification, the void volume of a Sephacryl S-300 column, was found to contain only a few proteins visible by Coomassie blue staining, one of which is likely to be albumin (68 kDa, pI 6.4). While this protein was modified by both Arg and Lys, the majority of label was found in areas not showing Coomassie blue staining. This indicates that of the many potential targets of post-translational arginylation and lysylation, most are proteins of relatively low abundance. A variety of proteins were modified by Arg or Lys alone while others were modified by both Arg and Lys. A high molecular weight protein (175 kDa, pI 9.0) was modified only by Lys and only at 2 h post crush. Of a variety of modified proteins of approximately 17 kDa one (pI 6.3) was modified by both Arg and Lys and at both time points, while another (pI 9.0) was modified at both time points, but only by Lys. The results show that Arg and Lys can be added post-translationally to a large number of low abundance, soluble sciatic nerve proteins, and that some of those proteins are modified only by Arg or Lys while others are modified by both Arg and Lys. Also, the modification of certain proteins appears to be associated specifically with the immediate response of a nerve to injury (e.g. 88 kDa, pI 7.1) while others are associated with the regenerative period (e.g. 56 kDa, pI 7.4).  相似文献   
57.
Both axonal and glial components of nerve are capable of carrying out reactions in which Arg, Lys, Leu, Pro, Val, AJa and Ser can be covalently linked to endogenous proteins in reactions which require tRNA but occur in the absence of ribosomes and ribosomal RNA. These posttranslational protein modifications appear to play important roles in nerve regeneration since they are increased more than 10-fold within 2 h of a crush injury in nerves which are capable of regeneration, but are not activated in nerves not capable of regrowth following injury. The regulation of the modification of proteins by Arg and Lys in vivo appears to be the function of separate peptides. The exogenous application of serine protease inhibitors (but not other protease inhibitors) mimics the effect of the endogenous peptides, suggesting that the endogenous regulators have serine protease inhibitory activity. The targets for modification are proteins of low abundance and thus far have been identified only in terms of their molecular weights and isoelectric points. The site of addition of Arg, but not the other amino acids, to target proteins is to the amino terminus. The addition of Arg to an amino terminus is likely to be involved in the ubiquitin mediated proteolysis of the modified protein. One of the most unusual findings in these series of experiments is that in regenerating sciatic nerves, amino acid modified proteins aggregate to form complexes of greater than 2 × 106 Da. The significance of this finding is not known. But we speculate that the aggregate may result from the assembly of an insoluble functional unit of the cell from soluble precursor proteins, and that the trigger for their assembly is amino acid modification.  相似文献   
58.
高位复杂性肛瘘的解剖学切除术   总被引:13,自引:0,他引:13  
张思奋  罗湛滨  任东林 《广东医学》2001,22(12):1098-1099
目的 探索治疗高位复杂性肛瘘较理想的手术方式。方法 应用解剖学原理,行瘘管切除、保留括约肌、内口缝合、创面开放术式,对高位复杂性肛瘘进行手术治疗。结果 45例一期治愈,1例二期治愈,无肛门失禁、肛门狭窄等并发症。结论 解剖学切除术是一种治疗高位复杂性肛瘘较理想的手术方式。  相似文献   
59.
为进一步研究呼吸道疾病时的粘液纤毛清除功能,采用99mTc-DTPA气溶胶吸入显像,通过电影显示定性和定量指标分析.对18 例健康受试者和患者进行了显像研究,得到气道清除率和粘液纤毛清除率的正常值,并观察了32例慢性阻塞性肺病(COPD)患者气管-支气管纤毛清除功能的改变.结果显示,健康受试者与COPD患者粘液纤毛清除率(mm/min)分别为3.89±0.92和1.32±0.59,两者比较有显著性差异(P<0.01),COPD患者不同时间气道清除率和粘液纤毛清除率均明显低于健康受试者(P<0.01).本研究方法简便客观,具有定性观察和定量分析的优点,对于呼吸系统其它疾病(如支气管扩张、原发性纤毛无运动)的研究及药物疗效的评价具有重要的临床实用价值.  相似文献   
60.
用RT-PCR技术从人胎盘组织内成功地扩增全长肝细胞生长因子(HGF)cDNA基因(2 184bp),并将其克隆至pGEM-T载体,经限制性核酸内切酶NdeⅠ,BglⅡ,HindⅢ,BamHⅠ和XhoⅠ的酶谱分析和DNA测序分析证实。再将其亚克隆至逆病毒载体pLNL-XHC,可进一步用于基因表达和基因治疗的研究。  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