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   1350873篇
  免费   103089篇
  国内免费   1839篇
耳鼻咽喉   17502篇
儿科学   43207篇
妇产科学   36976篇
基础医学   200403篇
口腔科学   36742篇
临床医学   126727篇
内科学   266621篇
皮肤病学   28298篇
神经病学   109491篇
特种医学   49707篇
外国民族医学   269篇
外科学   193115篇
综合类   27102篇
现状与发展   4篇
一般理论   645篇
预防医学   112053篇
眼科学   30375篇
药学   98395篇
  6篇
中国医学   2146篇
肿瘤学   76017篇
  2019年   11395篇
  2018年   15193篇
  2017年   11631篇
  2016年   12693篇
  2015年   14680篇
  2014年   20372篇
  2013年   31240篇
  2012年   42910篇
  2011年   45466篇
  2010年   26285篇
  2009年   25200篇
  2008年   43038篇
  2007年   46151篇
  2006年   45611篇
  2005年   44869篇
  2004年   43155篇
  2003年   41247篇
  2002年   40083篇
  2001年   56911篇
  2000年   57748篇
  1999年   48961篇
  1998年   14552篇
  1997年   13235篇
  1996年   13519篇
  1995年   12778篇
  1994年   11875篇
  1992年   38815篇
  1991年   38243篇
  1990年   36960篇
  1989年   35783篇
  1988年   33161篇
  1987年   32536篇
  1986年   30999篇
  1985年   29329篇
  1984年   22646篇
  1983年   19884篇
  1982年   12240篇
  1981年   11135篇
  1979年   21408篇
  1978年   15922篇
  1977年   13322篇
  1976年   12305篇
  1975年   13223篇
  1974年   15942篇
  1973年   15701篇
  1972年   14756篇
  1971年   13735篇
  1970年   12980篇
  1969年   12196篇
  1968年   11359篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
51.
Pharmaceutical Chemistry Journal - Three extracts were produced from the above-ground part of the meadowsweet Filipendula ulmaria (L.) Maxim. using water, 40% ethanol, and 70% ethanol. Comparative...  相似文献   
52.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  相似文献   
53.
As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n > 400 total) examining the power of society’s widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which—notably—remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.  相似文献   
54.
55.
56.
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.  相似文献   
57.
58.
59.
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression.  相似文献   
60.
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