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   668篇
  免费   82篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   40篇
妇产科学   8篇
基础医学   119篇
口腔科学   18篇
临床医学   49篇
内科学   163篇
皮肤病学   9篇
神经病学   31篇
特种医学   80篇
外科学   82篇
综合类   62篇
预防医学   27篇
眼科学   11篇
药学   28篇
肿瘤学   29篇
  2022年   6篇
  2021年   8篇
  2020年   7篇
  2019年   2篇
  2018年   8篇
  2017年   4篇
  2016年   11篇
  2015年   16篇
  2014年   15篇
  2013年   20篇
  2012年   16篇
  2011年   15篇
  2010年   24篇
  2009年   33篇
  2008年   18篇
  2007年   24篇
  2006年   38篇
  2005年   10篇
  2004年   10篇
  2003年   6篇
  2002年   14篇
  2001年   12篇
  2000年   12篇
  1999年   20篇
  1998年   43篇
  1997年   35篇
  1996年   45篇
  1995年   20篇
  1994年   22篇
  1993年   25篇
  1992年   23篇
  1991年   24篇
  1990年   8篇
  1989年   13篇
  1988年   26篇
  1987年   14篇
  1986年   11篇
  1985年   18篇
  1984年   13篇
  1983年   11篇
  1982年   7篇
  1981年   4篇
  1980年   10篇
  1979年   6篇
  1978年   2篇
  1977年   4篇
  1976年   6篇
  1975年   4篇
  1973年   3篇
  1972年   2篇
排序方式: 共有757条查询结果,搜索用时 31 毫秒
71.
72.
73.
74.
Dai  CH; Krantz  SB; Zsebo  KM 《Blood》1991,78(10):2493-2497
To understand the factors that regulate the early growth and development of immature erythroid progenitor cells, the burst-forming units-erythroid (BFU-E), it is necessary to have both highly purified target cells and a medium free of serum. When highly purified human blood BFU-E were cultured in a serum-free medium adequate for the growth of later erythroid progenitors, BFU-E would not grow even with the addition of recombinant human interleukin-3 (rIL-3), known to be essential for these cells. However, the addition of recombinant human stem cell factor (rSCF), which supports germ cell and pluripotential stem cell growth, stimulated BFU-E to grow equally well in serum-free as in serum-containing medium. Limiting dilution studies showed that rSCF acts directly on the BFU-E that do not require accessory cells for growth. Furthermore, rSCF was necessary for BFU-E development during the initial 7 days of culture, until these cells reached the stage of the late progenitors, the colony-forming units-erythroid (CFU-E). These studies indicate that early erythropoiesis is dependent on the direct action of SCF that not only affects early stem cells but is continually necessary for the further development of committed erythroid progenitor cells until the CFU-E stage of maturation.  相似文献   
75.
Abstract: In hemodialysis, a certain degree of bacterial contamination on the dialysate side is a regular finding. Concern has been growing that this contamination may lead to a chronic inflammatory response in the patient. Ultrafiltration of dialysate can be used to reduce bacterial content and levels of cytokine-inducing substances upstream of the patient's dialyzer. The aim of this study was to test in vitro the rejection capacity of a polysulfone hollow-fiber ultrafilter (ETF 609, NISSHO Co., Osaka, Japan) challenged with bacterial filtrates derived from Pseudomonus aeruginosa PA 103. Results showed a reduction of interleukin-Iβ-inducing activity (measured on peripheral blood mononuclear cells) from 5,035 ± 394 pg/ml prefilter to nondetectable levels postfilter and endotoxin levels (limulus amebocyte lysate assay) of 4,167 ± 1,079 versus 12 ± 2 pg/ml, respectively. In conclusion, ultrafiltration of dialysate with the polysulfone ultrafilter ETF 609 leads to a potent reduction of cytokine-inducing activity.  相似文献   
76.
Karkouti  K  Beattie  WS  Dattilo  KM  McCluskey  SA  Ghannam  M  Hamdy  A  Fedorko  L  Yau  TM 《Journal canadien d'anesthésie》2005,52(1):A64-A64
Canadian Journal of Anesthesia/Journal canadien d'anesthésie -  相似文献   
77.
78.
Although amebic liver abscess can virtually always be successfully treated medically, percutaneous drainage has been advocated recently. In 96 recently treated patients, therapeutic aspiration and percutaneous drainage were rarely needed. Most cases were correctly diagnosed by means of clinical, laboratory, and sonographic findings. Abscesses in only 13 (13.5%) patients were diagnostically aspirated. An abscess in one patient was therapeutically aspirated because the patient was responding slowly to medical therapy. No patient required catheter drainage. The key to successful amebic abscess management is medical therapy. Therapeutic drainage is rarely needed. Successfully treated patients occasionally respond slowly to medical therapy, and successfully treated amebic abscesses may enlarge or become bizarre-appearing on sonograms. This should not prompt therapeutic drainage. Diagnostic aspiration is appropriate when amebic and pyogenic abscesses are indistinguishable using clinical and imaging findings. Rare indications for therapeutic aspiration or drainage include pyogenic superinfection and large, juxtacardiac abscesses (potential intrapericardial rupture).  相似文献   
79.
Fifteen allograft transplant recipients acquired lymphoproliferative disorders after immunosuppressive therapy with cyclosporine and steroids. Many of these lymphoproliferative disorders regressed or disappeared completely after reduction of cyclosporine dose. This disease has several aspects that distinguish it from usual posttransplantation lymphomas that occur with regimens that do not contain cyclosporine. The time course from transplantation to onset of lymphoma is relatively short, with an average of approximately 8 months. Organs show a wide spectrum of abnormalities typical of other immunosuppression-associated lymphomas, but there is unique sparing of the central nervous system. The tumor is also unique in that it responds to a decrease in the cyclosporine dose.  相似文献   
80.
Quantitative SPECT brain imaging was performed in five normal subjects and in six ambulatory patients with Alzheimer's disease before the initiation of treatment with tetrahydroaminoacridine (THA) and lecithin. Imaging data were acquired with a single-head SPECT camera and a high-resolution collimator after the intravenous injection of 5 mCi of (p,5n) I-123 IMP. Uptake per pixel in 28 regions of interest in the transverse projection of each study was normalized to uptake per pixel in the cerebellum. Perfusion in the patients with Alzheimer's disease was decreased compared with that of the subjects. Perfusion was decreased greater than 2 SD below the mean in the posterior parietal cortex of 5/6 patients, in the temporal cortex of 3/6 patients, and in the frontal cortex of 2/6 patients with Alzheimer's disease. SPECT imaging was repeated in the six patients after initial titration to peak therapy with oral THA (75 to 200mg per day). The same abnormalities were again seen in the same patients. No dramatic clinical or behavioral change in cerebral perfusion was observed from initial treatment of Alzheimer's disease with THA and lecithin.  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