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   3249484篇
  免费   249836篇
  国内免费   6281篇
耳鼻咽喉   48121篇
儿科学   100107篇
妇产科学   89117篇
基础医学   454586篇
口腔科学   96167篇
临床医学   291097篇
内科学   631517篇
皮肤病学   68759篇
神经病学   269063篇
特种医学   129208篇
外国民族医学   1251篇
外科学   494595篇
综合类   78271篇
现状与发展   7篇
一般理论   1309篇
预防医学   252946篇
眼科学   78193篇
药学   244129篇
  8篇
中国医学   6378篇
肿瘤学   170772篇
  2018年   31684篇
  2016年   27246篇
  2015年   30755篇
  2014年   44177篇
  2013年   67512篇
  2012年   90109篇
  2011年   95215篇
  2010年   56184篇
  2009年   54240篇
  2008年   90858篇
  2007年   97388篇
  2006年   98349篇
  2005年   95979篇
  2004年   92534篇
  2003年   89634篇
  2002年   88547篇
  2001年   149528篇
  2000年   154599篇
  1999年   131101篇
  1998年   37323篇
  1997年   34010篇
  1996年   33193篇
  1995年   32066篇
  1994年   30054篇
  1993年   27959篇
  1992年   104907篇
  1991年   101263篇
  1990年   98270篇
  1989年   95137篇
  1988年   88387篇
  1987年   87097篇
  1986年   82967篇
  1985年   79255篇
  1984年   59913篇
  1983年   51054篇
  1982年   31023篇
  1981年   27789篇
  1980年   26045篇
  1979年   56777篇
  1978年   40178篇
  1977年   34363篇
  1976年   31763篇
  1975年   34484篇
  1974年   41902篇
  1973年   40156篇
  1972年   37999篇
  1971年   35396篇
  1970年   33431篇
  1969年   31372篇
  1968年   28865篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
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   
942.
Artificial dopamine agonists are widely employed for the treatment of idiopathic parkinsonism. Pleuropulmonary disease has previously been reported to occur with the use of bromocriptine and mesulergine. We report similar adverse effects induced by the newer agonists lisuride and cabergoline. All these agents are tetracyclic ergot derivatives. This suggests a causal link between ergot-derived dopamine agonists and pleuropulmonary disease.  相似文献   
943.
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   
944.
Postencephalitic acquired Tourette-like syndrome in a child.   总被引:1,自引:0,他引:1  
R S Northam  H S Singer 《Neurology》1991,41(4):592-593
We report a 6-year-old girl who developed a Tourette-like syndrome following presumed herpes encephalitis. This case suggests that tics can be acquired in childhood and may be associated with lesions involving basal ganglia or limbic circuitry.  相似文献   
945.
946.
947.
Computer tomography (CT) of the brain is of value for finding potentially correctable lesions in adult patients with new onset seizures. The value of CT is unknown, however, for finding such lesions in adult chronic epileptic patients without prior CT. We compared a group of 177 adult patients who had CT within a year from the onset of seizures to a group of 93 patients who had a history of seizures for more than a year before CT was performed. In the first group, 33 potentially correctable lesions (19%) were found including 17 tumors. The group with chronic epilepsy had 4 (4%) potentially correctable lesions: 3 arteriovenous malformations and 1 meningioma. It seems that CT is of value in discovering potentially removable lesions in chronic epileptic patients, but the likelihood is relatively small. The incidence of stable structural lesions seems to be similar in the two groups.  相似文献   
948.
Forty-two therapists conducting individual psychotherapy with schizophrenic outpatients in a public mental health system responded to a questionnaire that focused on the types of interventions used and the issues and problems encountered in therapy. The therapists spent 59 percent of their time in supportive, problem-solving work and only 32 percent in traditional psychotherapeutic interventions, such as providing insight. The most common issues in therapy were relationship problems, family concerns, depression, losses, and the role of medications in the client's life. The most significant impediments to therapeutic work were the lack of community resources, the client's noncompliance with medications and lack of motivation, and dual diagnoses. Suggestions are offered for improving psychotherapy with schizophrenic outpatients in the public mental health system.  相似文献   
949.
950.
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