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   1891篇
  免费   86篇
  国内免费   2篇
耳鼻咽喉   12篇
儿科学   122篇
妇产科学   31篇
基础医学   237篇
口腔科学   70篇
临床医学   122篇
内科学   380篇
皮肤病学   18篇
神经病学   291篇
特种医学   33篇
外科学   286篇
综合类   6篇
预防医学   81篇
眼科学   29篇
药学   161篇
中国医学   1篇
肿瘤学   99篇
  2023年   7篇
  2022年   24篇
  2021年   54篇
  2020年   23篇
  2019年   49篇
  2018年   42篇
  2017年   27篇
  2016年   31篇
  2015年   32篇
  2014年   34篇
  2013年   54篇
  2012年   93篇
  2011年   122篇
  2010年   55篇
  2009年   63篇
  2008年   98篇
  2007年   111篇
  2006年   103篇
  2005年   93篇
  2004年   73篇
  2003年   73篇
  2002年   71篇
  2001年   72篇
  2000年   81篇
  1999年   63篇
  1998年   26篇
  1997年   18篇
  1996年   14篇
  1995年   15篇
  1994年   12篇
  1993年   7篇
  1992年   33篇
  1991年   23篇
  1990年   34篇
  1989年   33篇
  1988年   31篇
  1987年   30篇
  1986年   22篇
  1985年   15篇
  1984年   13篇
  1983年   10篇
  1980年   5篇
  1979年   5篇
  1978年   6篇
  1977年   5篇
  1975年   5篇
  1973年   5篇
  1971年   6篇
  1930年   6篇
  1927年   4篇
排序方式: 共有1979条查询结果,搜索用时 0 毫秒
41.
42.
43.
44.
45.
Left ventricular false tendons (or anomalous bands) have been described in several anatomic studies. Recently the echocardiographic features of such false tendons have been reported also. We have found a prevalence of 36 cases in 1,600 consecutive patients examined (2.2%). False tendons represent a rather common and benign phenomenon. Echocardiography is the most useful tool in the detection of false tendons.  相似文献   
46.
In 112 untreated myeloma patients we have analysed the immunophenotype of plasma cells both by immunofluorescence (IF) and immunocytochemistry (APAAP). Both techniques yielded similar results pointing to an important degree of heterogeneity in antigenic expression not only between different patients but also within the same patient. The expression of CD38 and Han-PC1 antigens (Ags) was almost constant (greater than 90% positive cases), while CD9 was detected in 66% of the cases. On the other hand, less than one third of patients were positive for CD10, CD20 and HLA-DR and generally with a weak expression (less than 30% positive plasma cells). In occasional cases plasma cells were weakly positive for the myelomonocytic markers CD13 (9%), CD15 (25%) and CD14 (6%). The possibility that this heterogeneity might be the result of different stages of differentiation of the neoplastic clone is suggested both by the positive correlation in the expression of some of these antigens (CD10, CD9, CD20, HLA-DR) and by the relationship between CD10 and myeloid antigens with immature plasma cell morphology. Finally, the cALLA antigen does not seem to be of significant value in predicting survival. Moreover, none of the other markers explored showed a clear influence in the course of the disease, although the tendency towards a lower survival found for the CD20+ cases as well as the association of the expression of some antigens and advanced clinical stage, may warrant further studies in a larger series of patients.  相似文献   
47.
The coronavirus disease 2019 pandemic presents unprecedented challenges for the health care system. The pressure on health care staff continues to intensify, accentuated by the confinement (lockdown) of the population and the unprecedented duration of this emergency. Separately and especially together, overwork, degraded conditions of care because of the never-ending emergency, and the risk of exposure to the virus can lead to acute psychological distress or signs of burnout.This original program was developed at Cochin Hospital in Paris, France to prevent these potentially dramatic psychological consequences, support the medical staff, and identify those most affected to offer them specific care. A program and a space for relaxation and support for hospital caregivers by hospital caregivers, the Port Royal Bulle (the Bubble) offers these workers help in decompression and relaxation. It combines a warm and caring welcome that promotes attention, listening, conversations, and exchanges as needed, empathetic support, and the ability to participate in soothing, relaxing, or low-impact physical activities. It takes care of caregivers. The Bubble is a program that is simple to set up and that appears to meet professionals' expectations. Making it permanent and enlarging its scale, as a complement to existing programs, might help to support health care personnel in their work.  相似文献   
48.
The cell-cycle status of hematopoietic stem and progenitor cells (HSPCs) becomes activated following chemotherapy-induced stress, promoting bone marrow (BM) regeneration; however, the underlying molecular mechanism remains elusive. Here we show that BM-resident group 2 innate lymphoid cells (ILC2s) support the recovery of HSPCs from 5-fluorouracil (5-FU)–induced stress by secreting granulocyte-macrophage colony-stimulating factor (GM-CSF). Mechanistically, IL-33 released from chemo-sensitive B cell progenitors activates MyD88-mediated secretion of GM-CSF in ILC2, suggesting the existence of a B cell–ILC2 axis for maintaining hematopoietic homeostasis. GM-CSF knockout mice treated with 5-FU showed severe loss of myeloid lineage cells, causing lethality, which was rescued by transferring BM ILC2s from wild-type mice. Further, the adoptive transfer of ILC2s to 5-FU–treated mice accelerates hematopoietic recovery, while the reduction of ILC2s results in the opposite effect. Thus, ILC2s may function by “sensing” the damaged BM spaces and subsequently support hematopoietic recovery under stress conditions.  相似文献   
49.
Stroke affects primarily aged and co-morbid people, aspects not properly considered to date. Since angiogenesis/vasculogenesis are key processes for stroke recovery, we purposed to determine how different co-morbidities affect the outcome and angiogenesis/vasculogenesis, using a rodent model of metabolic syndrome, and by dynamic enhanced-contrast imaging (DCE-MRI) to assess its non-invasive potential to determine these processes. Twenty/twenty-two month-old corpulent (JCR:LA-Cp/Cp), a model of metabolic syndrome and lean rats were used. After inducing the experimental ischemia by transient MCAO, angiogenesis was analyzed by histology, vasculogenesis by determination of endothelial progenitor cells in peripheral blood by flow cytometry and evaluating their pro-angiogenic properties in culture and the vascular function by DCE-MRI at 3, 7 and 28 days after tMCAO. Our results show an increased infarct volume, BBB damage and an impaired outcome in corpulent rats compared with their lean counterparts. Corpulent rats also displayed worse post-stroke angiogenesis/vasculogenesis, outcome that translated in an impaired vascular function determined by DCE-MRI. These data confirm that outcome and angiogenesis/vasculogenesis induced by stroke in old rats are negatively affected by the co-morbidities present in the corpulent genotype and also that DCE-MRI might be a technique useful for the non-invasive evaluation of vascular function and angiogenesis processes.  相似文献   
50.
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