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   380392篇
  免费   24235篇
  国内免费   2816篇
耳鼻咽喉   5231篇
儿科学   8226篇
妇产科学   10087篇
基础医学   53216篇
口腔科学   11800篇
临床医学   30180篇
内科学   78624篇
皮肤病学   8575篇
神经病学   27238篇
特种医学   13951篇
外国民族医学   82篇
外科学   60957篇
综合类   9959篇
现状与发展   1篇
一般理论   64篇
预防医学   17457篇
眼科学   9487篇
药学   31040篇
  1篇
中国医学   2195篇
肿瘤学   29072篇
  2021年   2641篇
  2019年   2756篇
  2018年   4556篇
  2017年   3461篇
  2016年   3547篇
  2015年   4046篇
  2014年   5715篇
  2013年   7406篇
  2012年   10059篇
  2011年   10248篇
  2010年   6228篇
  2009年   5876篇
  2008年   9510篇
  2007年   10337篇
  2006年   10252篇
  2005年   9346篇
  2004年   8851篇
  2003年   8574篇
  2002年   8262篇
  2001年   28285篇
  2000年   28819篇
  1999年   23698篇
  1998年   5181篇
  1997年   4263篇
  1996年   3849篇
  1995年   3497篇
  1994年   3117篇
  1993年   2857篇
  1992年   16076篇
  1991年   14833篇
  1990年   14187篇
  1989年   13985篇
  1988年   12617篇
  1987年   12080篇
  1986年   11122篇
  1985年   10330篇
  1984年   6922篇
  1983年   5605篇
  1982年   2724篇
  1979年   5486篇
  1978年   3356篇
  1977年   2983篇
  1975年   2643篇
  1974年   3068篇
  1973年   2872篇
  1972年   2836篇
  1971年   2775篇
  1970年   2510篇
  1969年   2545篇
  1968年   2252篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
We report an 80-year-old Japanese male with four primary malignant tumors: malignant melanoma, prostatic cancer, malignant lymphoma, and renal cell carcinoma, which occurred in that respective order. The combination of malignant melanoma and malignant lymphoma is rare. The patient was treated with BCG after an operation for malignant melanoma. He was also treated with cobalt 60 irradiation after an operation for prostatic cancer. We also discuss other reports of multiple malignant tumors and suggest some possible causes of this patient's primary malignant tumors.  相似文献   
52.
53.
54.
55.
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   
56.
57.
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   
58.
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   
59.
60.
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   
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