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   1303535篇
  免费   96576篇
  国内免费   2392篇
耳鼻咽喉   18460篇
儿科学   43096篇
妇产科学   38291篇
基础医学   191158篇
口腔科学   35837篇
临床医学   110789篇
内科学   257261篇
皮肤病学   27143篇
神经病学   101336篇
特种医学   51101篇
外国民族医学   379篇
外科学   201181篇
综合类   27757篇
现状与发展   2篇
一般理论   302篇
预防医学   94811篇
眼科学   29625篇
药学   99935篇
  7篇
中国医学   3099篇
肿瘤学   70933篇
  2018年   12721篇
  2016年   10688篇
  2015年   12436篇
  2014年   17043篇
  2013年   25700篇
  2012年   35465篇
  2011年   37893篇
  2010年   22420篇
  2009年   21027篇
  2008年   36382篇
  2007年   39387篇
  2006年   39898篇
  2005年   39092篇
  2004年   37515篇
  2003年   36477篇
  2002年   35926篇
  2001年   58944篇
  2000年   60412篇
  1999年   51464篇
  1998年   14542篇
  1997年   13066篇
  1996年   13283篇
  1995年   12526篇
  1994年   11933篇
  1993年   11007篇
  1992年   41388篇
  1991年   40745篇
  1990年   40241篇
  1989年   39044篇
  1988年   36459篇
  1987年   35624篇
  1986年   34024篇
  1985年   32410篇
  1984年   24116篇
  1983年   20959篇
  1982年   12464篇
  1981年   11001篇
  1979年   22790篇
  1978年   15971篇
  1977年   13812篇
  1976年   13049篇
  1975年   14278篇
  1974年   16791篇
  1973年   16153篇
  1972年   15416篇
  1971年   14292篇
  1970年   13291篇
  1969年   12803篇
  1968年   12054篇
  1967年   10547篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Beta-adrenergic receptor density on T cells from healthy humans is greatest on suppressor cells (CD8+, CD28-) and the effect of catecholamines, secreted by the sympathetic nervous system, predominates on this subset. The sympathetic skin response, a measure of sympathetic nervous system function, is absent in most patients with chronic progressive multiple sclerosis (MS). We measured beta-adrenergic receptor density on suppressor cells, cytotoxic cells, and monocytes from patients with chronic progressive MS and healthy control subjects. Control receptor density on suppressor cells was 2.8 +/- 0.3 fmol/10(6) cells versus a density of 5.1 +/- 0.7 fmol/10(6) cells for patients. Cytotoxic cell (CD8+, CD28+) receptor density was 1.4 +/- 0.4 fmol/10(6) cells in control subjects and 0.9 +/- 0.3 fmol/10(6) cells in the patients. Monocytes displayed beta-adrenergic receptor densities of 2.6 +/- 0.4 fmol/10(6) cells in normal individuals and 2.7 +/- 0.4 fmol/10(6) cells in the patient group. CD8 lymphocyte beta-adrenergic receptor densities in patients with relapsing-remitting and those with stable MS were not different from control values, yet were significantly less than the values for patients with chronic progressive MS. We find that mononuclear cells from healthy control subjects and patients with chronic progressive MS proliferate in response to 200 units/ml of recombinant human interleukin-2 (IL-2) similarly. However, IL-2 treatment increased beta-adrenergic receptor density on normal mononuclear cells, but failed to increase it on mononuclear cells from patients with chronic progressive MS.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
992.
Reports on individual nonbehavioral child and adolescent psychotherapy since 1963 are reviewed. Inclusion criteria required some minimal contrasting group. Forty-three studies were assessed for basic methodological adequacy and main findings. The authors conclude that summary impressions from this body of literature cannot be made due to the magnitude of the flaws in basic psychotherapy research methodology. Suggestions are made regarding the future of child and adolescent psychotherapy research.  相似文献   
993.
994.
Bipolar disorder is a serious mental illness affecting a large number of Americans. While lithium, the treatment of choice for this disorder, is usually effective, a substantial number of individuals with bipolar disorder are not helped by lithium or are intolerant to its side effects. Consequently, investigators are searching for alternative drugs in order to treat lithium-resistant patients. Although a number of alternative drug treatments have been discussed in the literature, only the anticonvulsants carbamazepine and valproate appear to warrant serious consideration at this time. Future research will further define their roles as antimanic agents.  相似文献   
995.
996.
997.
In the processing of the waste products of phosphorus containing fertilizer production, several major health-related factors were identified depending on the industrial site's peculiarities: unfavourable microclimate conditions (both cold and heat), relative temperature differences, noise and vibration caused by the equipment, semi-product's, additives' and finished product's dusts, fluorine- and phosphorus-containing substances' affects and poor illumination. The proposed data were used for health-related improvements in the occupational conditions.  相似文献   
998.
NTS fallout-induced multiple myeloma in Utah.   总被引:1,自引:0,他引:1  
  相似文献   
999.
1000.
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