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   1345177篇
  免费   102856篇
  国内免费   4330篇
耳鼻咽喉   16868篇
儿科学   43818篇
妇产科学   36528篇
基础医学   199537篇
口腔科学   36006篇
临床医学   131205篇
内科学   261025篇
皮肤病学   26596篇
神经病学   112905篇
特种医学   48671篇
外国民族医学   369篇
外科学   185817篇
综合类   28806篇
现状与发展   1篇
一般理论   466篇
预防医学   114886篇
眼科学   29166篇
药学   99609篇
  6篇
中国医学   3185篇
肿瘤学   76893篇
  2021年   11263篇
  2019年   11923篇
  2018年   16668篇
  2017年   12531篇
  2016年   13501篇
  2015年   15528篇
  2014年   21255篇
  2013年   32633篇
  2012年   45180篇
  2011年   47909篇
  2010年   27578篇
  2009年   25434篇
  2008年   43475篇
  2007年   45820篇
  2006年   45904篇
  2005年   44295篇
  2004年   42205篇
  2003年   40121篇
  2002年   38888篇
  2001年   60989篇
  2000年   62645篇
  1999年   52403篇
  1998年   14701篇
  1997年   13374篇
  1996年   13192篇
  1995年   12511篇
  1994年   11674篇
  1993年   10973篇
  1992年   41647篇
  1991年   40831篇
  1990年   39502篇
  1989年   37404篇
  1988年   34642篇
  1987年   33743篇
  1986年   32200篇
  1985年   30687篇
  1984年   23067篇
  1983年   19618篇
  1982年   11773篇
  1979年   20823篇
  1978年   14826篇
  1977年   12072篇
  1976年   11890篇
  1975年   12133篇
  1974年   14812篇
  1973年   14486篇
  1972年   13370篇
  1971年   12428篇
  1970年   11490篇
  1969年   10416篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
952.
953.
954.
955.
956.
957.
Forty-six (85%) basal cell and eight (15%) squamous cell carcinomas of the eyelids were treated with electron beams between 1963 and 1983. Lesion sizes ranged from microscopic to 4 cm, with 28 lesions larger than 1 cm. Thirty-eight lesions were treated with radiotherapy after incisional biopsy, and 16 were treated after excisional biopsy (specimens showed positive margins). Doses varied from 45 to 72 Gy, with daily fractions ranging from 2.12 to 4.0 Gy. There were six disease recurrences (10.9%): three in the treatment field and three at the treatment margin. Four of six recurrences were subsequently controlled by limited surgical excision and repair with preservation of the eye, whereas the other two required enucleation. Treatment sequelae such as skin atrophy, telangiectasis, and cosmetic results were evaluated in terms of radiotherapy parameters, pretreatment surgery, and size of the lesion. In 44 patients, the overall cosmetic result was judged as good to excellent, five patients had a mild to modest degree of deformity, and five had significant deformity. Such deformity was usually associated with tumor destruction or previous surgery. No major complications were noted.  相似文献   
958.
Weaver mutant mice are characterized by a decrease in striatal dopamine (DA), which is associated with a progressive loss of DA neurones in the substantia nigra. This mutant thus provides the opportunity to examine the functional effects of DA neurones grafted to the striatum in a genetic model of parkinsonism. Ventral mesencephalic tissue from normal foetuses was placed on the surface of the right dorsal striatum of adult weaver mutants. After grafting, animals were tested for methamphetamine-induced circling behaviour. Mutants with DA containing grafts displayed a significant circling bias toward the left, non-grafted side. Mutants without grafts did not display any rotational bias to either side. These results demonstrate that grafted DA containing neurones establish a functional innervation of the weaver striatum and suggest that grafting of neural tissue is a viable approach in restoring function in genetic degenerative disorders of the nigrostriatal system.  相似文献   
959.
Serum protein electrophoresis (SPEP) data obtained at diagnosis were available for 98 of 342 patients with chronic lymphocytic leukemia (CLL) identified in a population-based case-control epidemiologic study. Patients tested with SPEP at diagnosis were significantly younger, more likely to have lymphadenopathy, and more likely to have had their conditions diagnosed at a university hospital than those not tested. Four categories of electrophoretic patterns were identified: normal (N = 56), hypogammaglobulinemia (N = 28), hypergammaglobulinemia (N = 11), and monoclonal gammopathy (N = 3). A higher proportion of those with hypergammaglobulinemia were black, and patients with hypergammaglobulinemia and monoclonal gammopathy were more likely to die within the first year following diagnosis than patients in the other SPEP groups. No association was found, however, between SPEP pattern and a clinical staging classification for CLL. These findings suggest that SPEP may be a useful adjunct in categorizing possible subtypes of CLL and developing future clinical staging classifications.  相似文献   
960.
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