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   1093篇
  免费   85篇
  国内免费   23篇
耳鼻咽喉   7篇
儿科学   47篇
妇产科学   54篇
基础医学   217篇
口腔科学   19篇
临床医学   116篇
内科学   304篇
皮肤病学   47篇
神经病学   36篇
特种医学   74篇
外科学   56篇
综合类   27篇
预防医学   67篇
眼科学   5篇
药学   95篇
肿瘤学   30篇
  2021年   12篇
  2020年   7篇
  2019年   15篇
  2018年   15篇
  2017年   11篇
  2016年   21篇
  2015年   20篇
  2014年   21篇
  2013年   40篇
  2012年   43篇
  2011年   32篇
  2010年   32篇
  2009年   35篇
  2008年   41篇
  2007年   53篇
  2006年   55篇
  2005年   53篇
  2004年   44篇
  2003年   32篇
  2002年   31篇
  2001年   30篇
  2000年   27篇
  1999年   23篇
  1998年   26篇
  1997年   23篇
  1996年   35篇
  1995年   9篇
  1994年   23篇
  1993年   15篇
  1992年   15篇
  1991年   28篇
  1990年   25篇
  1989年   18篇
  1988年   26篇
  1987年   25篇
  1986年   21篇
  1985年   23篇
  1984年   15篇
  1983年   13篇
  1982年   9篇
  1981年   12篇
  1980年   11篇
  1979年   12篇
  1978年   11篇
  1977年   7篇
  1976年   9篇
  1975年   9篇
  1974年   8篇
  1973年   16篇
  1970年   8篇
排序方式: 共有1201条查询结果,搜索用时 31 毫秒
1.
2.
Pityriasis rosea (PR) is a relatively common disease although its aetiology has not yet been identified. It occurs worldwide and there is no racial susceptibility factor. It usually affects teenagers and young adults between 10 and 35 years of age. Typical PR is much easier to diagnose than the rare atypical forms. We report a rare case of vesicular PR in a black woman who had vesicular lesions limited to her palms and soles in addition to regular typical lesions. We devised an efficient oral erythromycin treatment for this patient.  相似文献   
3.
Two anemic patients with rheumatoid arthritis were treated with recombinant human erythropoietin (EPO) for 5 months. Both patients showed significant increases in hematocrit, red cell volumes, and marrow erythroid and megakaryocyte progenitor cells. No significant toxic effects from EPO were observed. These data indicate that EPO may be effective in overcoming the pathogenetic factors that limit erythropoiesis in rheumatoid arthritis.  相似文献   
4.
Polycythemia vera (PV) is a clonal disease of the hematopoietic stem cell characterized by a hyperplasia of marrow erythropoiesis, granulocytopoiesis, and megakaryocytopoiesis. We previously reported that highly purified PV blood burst-forming units-erythroid (BFU-E) are hypersensitive to recombinant human interleukin-3 (rIL-3). Because these cells may be only a subset, and not representative of marrow progenitors, we have now studied partially purified marrow hematopoietic progenitor cells. Dose-response experiments with PV marrow BFU-E showed a 38-fold increase in sensitivity to rIL-3 and a 4.3-fold increase in sensitivity to recombinant human erythropoietin (rEpo) compared with normal marrow BFU-E. In addition, PV marrow colony-forming units-granulocyte-macrophage (CFU-GM) and CFU-megakaryocyte (CFU-MK) also showed a marked hypersensitivity to rIL-3 and to human recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF). Dose-response curves with rGM-CSF and blood BFU-E showed a 48-fold increase in sensitivity. No effect of rIL-4, rIL-6, human recombinant granulocyte-CSF (rG-CSF), or macrophage-CSF (rM-CSF) was evident, nor was there any effect of PV cell-conditioned medium on normal BFU-E, when compared with normal cell-conditioned medium. Autoradiography with 125I-rEpo showed an increase in Epo receptors after maturation of PV BFU-E to CFU-E similar to that shown with normal BFU-E, but no increase of specific binding of 125I-rIL-3 by PV CD34+ cells was seen compared with normal CD34+ cells. These studies show that PV marrow hematopoietic progenitor cells are hypersensitive to rIL-3 and rGM-CSF, similar to PV blood BFU-E. While the mechanism does not appear to be due to enhanced binding of rIL-3, the hypersensitivity of PV progenitor cells to IL-3 and GM-CSF may be a key factor in the pathogenesis of PV.  相似文献   
5.
PURPOSE: Children with specific language impairment (SLI) often fail to produce past tense forms in obligatory contexts, although the factors affecting such inconsistency are not well understood. This study examined the influence of accompanying temporal adverbials (e.g., just, already) on the past tense production of these children. METHOD: Fifteen preschool-aged children with SLI, 15 typically developing children matched for age (TD-A) and 15 younger typically developing children matched for mean length of utterance (TD-MLU) participated in the study. The children responded to probes that obligated the use of past tense forms. The verbal context provided by the experimenter for half of the items included a temporal adverbial. RESULTS: Overall, the SLI and TD-MLU groups produced past tense less frequently than the children in the TD-A group, and there were no significant differences between the SLI and the TD-MLU groups. However, both the SLI and the TD-MLU participants produced past tense forms less frequently when temporal adverbials were included than when they were absent. CONCLUSIONS: These findings suggest that the tendency to use past tense by the children with SLI and their younger MLU-matched peers may not have been independent of other types of temporal information.  相似文献   
6.
7.
Changes in the incidence of coelic disease was studied among children born in Göteborg, Sweden, between 1970 and 1988. A total of 188 patients with coeliac disease were found. Of these, 83% were less than 2 years old at the time of their first duodenal biopsy and 74% of them have so far been verified according to the criteria of the European Society for Gastroenterology and Nutrition (ESPGAN). The cumulative incidence at 2 years of age/1000 liveborn infants increased significantly from 0.31 in the first birth cohort to 2.93 in the last. This increase could only partly be explained by improvements in detection. Weight for age at diagnosis was generally considerably below the reference value, but was slightly less affected towards the end of the period. The increase in incidence of coeliac disease is the first reported since the middle 1970s and makes the disease one of the most common chronic diseases among Swedish children.  相似文献   
8.
9.
10.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml ̄(-1)诱导HL-60细胞发生凋亡,而阻断HR20细胞于G_1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml ̄(-1)处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G_1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关  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