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   2468931篇
  免费   175539篇
  国内免费   3635篇
耳鼻咽喉   33595篇
儿科学   78994篇
妇产科学   65561篇
基础医学   365327篇
口腔科学   68059篇
临床医学   218421篇
内科学   482187篇
皮肤病学   55003篇
神经病学   195051篇
特种医学   90774篇
外国民族医学   490篇
外科学   366636篇
综合类   48060篇
现状与发展   12篇
一般理论   868篇
预防医学   197890篇
眼科学   57690篇
药学   184553篇
  11篇
中国医学   5012篇
肿瘤学   133911篇
  2021年   20923篇
  2019年   21774篇
  2018年   30897篇
  2017年   22798篇
  2016年   25119篇
  2015年   28273篇
  2014年   39025篇
  2013年   58435篇
  2012年   82617篇
  2011年   87698篇
  2010年   51124篇
  2009年   47492篇
  2008年   81164篇
  2007年   86555篇
  2006年   87030篇
  2005年   84130篇
  2004年   80225篇
  2003年   77027篇
  2002年   74465篇
  2001年   111059篇
  2000年   113991篇
  1999年   95475篇
  1998年   27415篇
  1997年   23925篇
  1996年   24317篇
  1995年   22946篇
  1994年   21091篇
  1993年   19874篇
  1992年   73208篇
  1991年   71214篇
  1990年   69559篇
  1989年   66713篇
  1988年   61335篇
  1987年   60080篇
  1986年   56207篇
  1985年   53931篇
  1984年   40006篇
  1983年   34004篇
  1982年   20188篇
  1979年   36774篇
  1978年   26248篇
  1977年   21799篇
  1976年   20900篇
  1975年   22470篇
  1974年   26986篇
  1973年   25702篇
  1972年   24051篇
  1971年   22876篇
  1970年   21043篇
  1969年   20168篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
32.
33.
34.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
35.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  相似文献   
36.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
37.
38.
39.
40.
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