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   548399篇
  免费   35961篇
  国内免费   8438篇
耳鼻咽喉   6953篇
儿科学   11610篇
妇产科学   14658篇
基础医学   77292篇
口腔科学   15990篇
临床医学   47315篇
内科学   106985篇
皮肤病学   11320篇
神经病学   37792篇
特种医学   19751篇
外国民族医学   126篇
外科学   81834篇
综合类   24889篇
现状与发展   18篇
一般理论   100篇
预防医学   29451篇
眼科学   13685篇
药学   46677篇
  75篇
中国医学   6357篇
肿瘤学   39920篇
  2022年   4375篇
  2021年   6991篇
  2020年   4685篇
  2019年   5903篇
  2018年   8083篇
  2017年   6298篇
  2016年   6381篇
  2015年   8171篇
  2014年   10990篇
  2013年   12525篇
  2012年   17608篇
  2011年   18933篇
  2010年   11274篇
  2009年   9945篇
  2008年   15661篇
  2007年   16794篇
  2006年   16810篇
  2005年   15440篇
  2004年   13651篇
  2003年   13152篇
  2002年   12349篇
  2001年   35021篇
  2000年   35919篇
  1999年   30026篇
  1998年   7733篇
  1997年   6616篇
  1996年   5601篇
  1995年   5095篇
  1994年   4553篇
  1993年   3998篇
  1992年   19691篇
  1991年   18472篇
  1990年   17597篇
  1989年   17266篇
  1988年   15718篇
  1987年   14983篇
  1986年   13894篇
  1985年   12975篇
  1984年   8779篇
  1983年   7207篇
  1979年   7309篇
  1978年   4497篇
  1977年   3922篇
  1975年   3803篇
  1974年   4392篇
  1973年   4242篇
  1972年   4135篇
  1971年   3982篇
  1970年   3623篇
  1969年   3645篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
With the increased use of indwelling central venous catheters, increasing numbers of cases of Rhodotorula fungemia have been observed in patients with neoplasia and neutropenia. In most patients with catheter-related Rhodotorula fungemia, the condition has been treated with broadspectrum antibiotics. We report two cases of central venous catheter-related Rhodotorula rubra fungemia that occurred in patients with acute myeloblastic leukemia. Both patients were in a state of neutropenia. One patient was treated with amphotericin B and his central venous catheter was removed, but he died of Klebsiella pneumoniae bacteremia. The other patient was treated with amphotericin B and discharged, with a central venous catheter, after recovery from neutropenia. Although the management of catheter-related Rhodotorula fungemia infections remains controversial, resolution of the underlying disease is more important than catheter removal for recovery from Rhodotorula rubra fungemia. Received: August 22, 2001 / Accepted: October 8, 2001  相似文献   
82.
83.
Smoking and stroke.   总被引:2,自引:0,他引:2  
The purpose of this review is to evaluate literature published since 1978 on the association between smoking and stroke. Two cohort studies found a dose-response relationship between the amount of cigarettes smoked per day and the relative risk of stroke. Also, two of the cohort studies found that when smoking ceased, the risk of stroke lessened (p less than 0.001). Nine case-control studies found a significant association between smoking and stroke for men and women. The biological association between smoking and stroke is plausible and several epidemiologic studies are supportive of this thesis. Additional, well-designed epidemiologic studies with a sufficient sample size to detect reasonably small odds ratios or relative risks (thus providing adequate statistical power) are warranted.  相似文献   
84.
In rodents, chronic estrogenization has been shown to induce degeneration of dendrites and myelin figures in the hypothalamic arcuate nucleus adjacent to peroxidase-positive astrocyte processes. Because in this brain region estradiol is metabolized to 2-hydroxyestradiol (catecholestrogen), we hypothesized that the latter may be oxidized by the astrocytic peroxidase activity to cytotoxic ortho-semiquinones as occurs in peripheral tissues. Cysteamine induces nonenzymatic peroxidase activity in cultured astroglia identical to that observed in vivo. Using electron spin resonance, we demonstrate robust peroxidase-catalyzed oxidation of 2-hydroxyestradiol and dopamine by cysteamine-pretreated astrocyte cultures relative to untreated controls. These results implicate the peroxidase-positive astrocytes in the pathogenesis of estradiol-related hypothalamic damage, parkinsonism, and other free-radical-related neurologic disorders.  相似文献   
85.
A new macrolide antibiotic, clarithromycin (TE-031, A-56268), was studied for its clinical efficacy in the field of pediatrics. Patients treated were infants and children ranging from 2 months to 11 years old suffering from acute bronchitis in 5 cases, acute tonsillitis in 2 cases, Mycoplasma pneumonia in 2 cases, pertussis in 6 cases, scarlatina in 1 case and acute enteritis in 2 cases, a total of 18 cases. TE-031 was administered 19.7-43.5 mg/kg in daily doses and lengths of treatment ranged from 4 to 19 days. As regards to its clinical efficacy, good or excellent results were obtained in all cases: excellent in 11 cases and good in 7 cases. No clinical side effects nor abnormal laboratory test values obviously attributable to TE-031 were observed.  相似文献   
86.
Following administration of phenothiazines for schizophrenia, a 25-year-old patient developed a malignant neuroleptic syndrome followed by bilateral periarticular ossification of the knees, with severely limited motion. Two years later, the patient regained useful motion after bilateral excision of the ossified tissue and intensive physiotherapy. No recurrence of ossification was observed 3 years after operation, and the patient has maintained almost normal motion.  相似文献   
87.
88.
S R Roffler  M H Yu  B M Chen  E Tung  M Y Yeh 《Cancer research》1991,51(15):4001-4007
Pseudomonas exotoxin A (PE) linked to the F(ab')2 fragment of 1H10, a murine monoclonal antibody recognizing a carbohydrate epitope of a glycoconjugate expressed on the surface of human cervical carcinoma tumor cells, was evaluated for in vitro and in vivo activity. PE can kill cells by ADP-ribosylating elongation factor 2 thus inhibiting protein synthesis. Disulfide- as well as thioether-linked immunotoxins (1H10-PE) killed cervical carcinoma cells in vitro and were 20-160 times more inhibitory to target than to control cells. Cell killing was antibody mediated as demonstrated by the reduction of 1H10-PE growth inhibition to target CaSki cells by free 1H10 F(ab')2. In addition, a control antibody immunotoxin was nontoxic to CaSki cells. Thioether-linked 1H10-PE administered either i.v. or i.p. suppressed the growth of established solid s.c. cervical carcinoma tumors xenografted in nude mice for over 30 days. Treatment with antibody alone or a control immunotoxin had no significant effect on tumor growth. Administration of immunotoxin i.p. was associated with less toxicity than administration i.v., but i.v. injections were more effective at suppressing the growth of established solid tumors.  相似文献   
89.
90.
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