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   3774127篇
  免费   302170篇
  国内免费   14680篇
耳鼻咽喉   50675篇
儿科学   119296篇
妇产科学   97610篇
基础医学   590298篇
口腔科学   102169篇
临床医学   339847篇
内科学   672799篇
皮肤病学   98423篇
神经病学   316628篇
特种医学   146812篇
外国民族医学   262篇
外科学   580643篇
综合类   113873篇
现状与发展   23篇
一般理论   2359篇
预防医学   310636篇
眼科学   88927篇
药学   260666篇
  26篇
中国医学   11409篇
肿瘤学   187596篇
  2021年   55582篇
  2020年   35381篇
  2019年   58475篇
  2018年   72711篇
  2017年   55493篇
  2016年   61349篇
  2015年   75102篇
  2014年   109316篇
  2013年   174721篇
  2012年   104290篇
  2011年   106130篇
  2010年   120683篇
  2009年   123621篇
  2008年   92716篇
  2007年   97294篇
  2006年   106788篇
  2005年   101548篇
  2004年   103264篇
  2003年   93198篇
  2002年   82561篇
  2001年   136064篇
  2000年   129629篇
  1999年   121992篇
  1998年   68582篇
  1997年   65256篇
  1996年   62992篇
  1995年   58538篇
  1994年   52533篇
  1993年   48892篇
  1992年   85042篇
  1991年   80971篇
  1990年   76671篇
  1989年   75109篇
  1988年   69019篇
  1987年   67207篇
  1986年   63535篇
  1985年   62765篇
  1984年   54869篇
  1983年   49581篇
  1982年   43615篇
  1981年   40986篇
  1980年   38456篇
  1979年   44845篇
  1978年   38238篇
  1977年   34917篇
  1976年   31962篇
  1975年   30786篇
  1974年   32485篇
  1973年   31176篇
  1972年   29037篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
To test the reported antipanic efficacy of clonazepam, the authors randomized 72 subjects with panic disorder to 6 weeks of treatment with either alprazolam, clonazepam, or placebo. Endpoint analysis demonstrated a significant beneficial effect of both active treatments, but not placebo treatment, on the frequency of panic attacks, overall phobia ratings, and the extent of disability. Comparison of the two active treatments revealed no significant differences and no consistent tendency for one agent to be favored over another, although power to detect small differences was limited. Sedation and ataxia were the most common side effects reported, but these effects were mild and transient and did not interfere with treatment outcome. The results of this double-blind, placebo-controlled trial are consistent with previous reports of clonazepam's antipanic efficacy.  相似文献   
993.
The presence of cytochrome P-45011 beta in rat brain was studied by immunohistochemistry using polyclonal rabbit antibodies raised against purified bovine adrenocortical P-45011 beta, which is involved in the steroid 11 beta-hydroxylation and glucocorticoid formation. The results showed that cytochrome P-45011 beta immunoreactivity is selectively localized to the tracts of myelinated fibers throughout the brain. The specificity of immunohistochemical stainings with P-45011 beta antibodies was established by control tests including nonimmune rabbit immunoglobulin Gs and P-45011 beta antibodies absorbed with purified antigen. Western immunoblots of homogenates from different brain areas with P-45011 beta antibodies, together with biochemical enzymatic assays for cytochrome P-45011 beta monooxygenase activity in these homogenates, confirmed the selective localization of this enzyme observed with immunohistochemistry. Cytochrome P-45011 beta and 11 beta-hydroxylase activity were detected in a homogenate from the cortical white matter (brain area rich in myelinated fibers) as in that from the rat adrenal, but were not detectable in a homogenate from the cerebral cortex (brain area poor in myelinated fibers). Furthermore, quantitation of the P-45011 beta bands on the immunoblots by the areal density revealed that the cortical white matter contains approximately 1.4 pmol of cytochrome P-45011 beta/mg of tissue protein, the value of which was about one sixth of the corresponding value estimated in the rat adrenal. This relatively high content of cytochrome P-45011 beta was also reflected in a relatively high level of 11 beta-hydroxylase activity measured in a homogenate of this brain area by biochemical enzymatic assays using [4-14C]-11-deoxycorticosterone.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
994.
995.
A total of 102 patients were examined, 32 of these with true eczema, 38 with exudative mycosis of the soles, and 32 with eczema etiologically related to a fungal infection. Analysis of the immune and biochemical reactions in the examinees has shown a marked reduction of adenyl nucleotides in the leukocytic suspension and neutrophils of patients with a mycotic infection as against those with true eczema. The lowest creatine phosphate levels were detected in the leukocytic suspension and neutrophils of the patients suffering from eczema etiologically related to mycosis and exudative mycosis of the soles. These results give grounds to search for effective corrective therapy.  相似文献   
996.
997.
This paper discusses the application of intravenous Kalipsol anesthesia in combination with Seduxen (Relanium) in 22 patients who underwent antro-mastoidectomy (expanded) and fronto-ethmoidectomy. No complications related to the method of anesthesia were identified. It is concluded that the use of Kalipsol anesthesia in urgent ENT operations provides better surgical intervention. This method ensures adequate analgesia during operation.  相似文献   
998.
999.
Formulae for the calculation of the count of microorganisms isolated from natural bacterial biocenoses of a child's body have been derived. The authors suggest a variant of simplified drip method for the computation of microorganism colonies in solid media. The described method helps cut down the nutrient media consumption at least 3-fold and is time-saving.  相似文献   
1000.
A fluid-fiber-collagen stress tensor is used to describe the rheology of the left ventricle of the heart. Linear theory is used to find the equilibrium solutions for the end-diastolic and end-systolic states of general axisymmetric shapes that are small perturbations of a thick-walled finite cylinder. The general problem can be studied by superposing the effects of variable midwall radius but constant wall thickness with those of variable wall thickness but constant midwall radius. A Fourier series representation is used to describe the midwall radius and thickness functions. Numerical calculations are performed to determine the deformed geometry and spatial distributions of tissue pressure, stresses, and fiber strains. The calculations proved to be highly accurate when compared to an analytical solution obtained for the special case of no fibers. The results show significant longitudinal differences when compared to results for the cylindrical geometry, with more sensitivity to variation in wall thickness than to variation in midwall radius.  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