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   2945篇
  免费   288篇
  国内免费   53篇
耳鼻咽喉   14篇
儿科学   137篇
妇产科学   39篇
基础医学   422篇
口腔科学   62篇
临床医学   366篇
内科学   695篇
皮肤病学   44篇
神经病学   204篇
特种医学   264篇
外科学   304篇
综合类   165篇
一般理论   3篇
预防医学   242篇
眼科学   24篇
药学   161篇
中国医学   3篇
肿瘤学   137篇
  2023年   31篇
  2022年   20篇
  2021年   50篇
  2020年   34篇
  2019年   27篇
  2018年   52篇
  2017年   73篇
  2016年   73篇
  2015年   53篇
  2014年   94篇
  2013年   142篇
  2012年   128篇
  2011年   110篇
  2010年   110篇
  2009年   111篇
  2008年   92篇
  2007年   135篇
  2006年   142篇
  2005年   123篇
  2004年   100篇
  2003年   101篇
  2002年   86篇
  2001年   100篇
  2000年   91篇
  1999年   74篇
  1998年   108篇
  1997年   82篇
  1996年   73篇
  1995年   67篇
  1994年   60篇
  1993年   59篇
  1992年   63篇
  1991年   46篇
  1990年   50篇
  1989年   50篇
  1988年   61篇
  1987年   48篇
  1986年   52篇
  1985年   52篇
  1984年   37篇
  1983年   21篇
  1982年   21篇
  1981年   15篇
  1980年   19篇
  1979年   15篇
  1978年   22篇
  1977年   23篇
  1976年   21篇
  1975年   12篇
  1972年   13篇
排序方式: 共有3286条查询结果,搜索用时 15 毫秒
1.
2.
Haaga  JR; Beale  SM 《Radiology》1986,161(3):829-830
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).  相似文献   
3.
PURPOSE: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1 protein expression correlated with genomic copy number changes. EXPERIMENTAL DESIGN: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1 staining. RESULTS: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P=0.006) or HER2 positive (P=0.039) and <50 years old at diagnosis (P=0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1 protein expression and reduced disease-free survival when stratified by either loss of ER (P=0.008) or PR (P=0.029) or HER2 overexpression (P=0.026). Overall, there was poor correlation between BRMS1 protein staining and copy number status. CONCLUSIONS: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors.  相似文献   
4.
Prolactin (PRL) and other trophic factors rapidly activate a nuclear pool(s) of protein kinase C (nPKC) in purified splenocyte nuclei. The PRL also enhanced [2-3H]glycerol incorporation into nuclear mono- and triacylglycerol. An assay was devised which not only probed the ability of the hormone to activate protein kinase C (PKC) but also demonstrated the presence of nuclear substrates. Using this methodology, a biphasic concentration-response curve to PRL was observed. Heterologous species of PRL and various growth factors also activated nPKC. The PRL-induced nPKC stimulation was antagonized by various immunomodulators, G protein-coupling inhibitors, PKC inhibitors, a calmodulin inhibitor, and a peripheral benzodiazepine agonist and antagonist. A monoclonal antibody to PKC, anti-rat PRL antiserum and a monoclonal anti-rat PRL receptor antibody antagonized PRL-induced PKC-dependent nuclear phosphorylation, further implicating nPKC and a PRL receptor-mediated activation process. Nuclear PKC may be a major target for trophic regulation in response to both positive and negative growth signals.  相似文献   
5.
Although the vulnerability of patients with sickle cell disease to infection with encapsulated organisms is well recognized, nosocomial transmission of infection has not been studied in this population. We describe eight serious, nosocomially transmitted infections in four adult patients hospitalized for complications of sickle cell disease, which led to death in one patient and prolonged hospital stays in three others. Although we have not surveyed all patients with sickle cell disease for rates of nosocomial infection, the cases presented suggest that these patients may be at increased risk. Risk can be reduced if health care workers are especially vigilant in adhering to handwashing and other infection control measures when caring for these patients. Additionally, we recommend that a patient with sickle cell disease not share a room with a patient known to have or suspected of having a nosocomial or community-acquired infectious disease.  相似文献   
6.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  相似文献   
7.
8.
9.
10.
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