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   14862篇
  免费   1015篇
  国内免费   6篇
  2023年   136篇
  2022年   269篇
  2021年   519篇
  2020年   376篇
  2019年   482篇
  2018年   583篇
  2017年   512篇
  2016年   681篇
  2015年   849篇
  2014年   930篇
  2013年   1070篇
  2012年   1157篇
  2011年   1066篇
  2010年   644篇
  2009年   577篇
  2008年   687篇
  2007年   681篇
  2006年   590篇
  2005年   529篇
  2004年   486篇
  2003年   429篇
  2002年   361篇
  2001年   264篇
  2000年   237篇
  1999年   196篇
  1998年   79篇
  1997年   75篇
  1996年   63篇
  1995年   59篇
  1994年   60篇
  1993年   52篇
  1992年   108篇
  1991年   84篇
  1990年   60篇
  1989年   75篇
  1988年   68篇
  1987年   85篇
  1986年   70篇
  1985年   55篇
  1984年   57篇
  1983年   38篇
  1982年   31篇
  1981年   32篇
  1980年   25篇
  1979年   44篇
  1978年   28篇
  1976年   28篇
  1975年   33篇
  1974年   24篇
  1973年   42篇
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
81.
Cell and Tissue Research - Cerebrospinal fluid (CSF)-contacting neurons were studied by means of electron microscopy in the spinal cord and/or terminal ventricle of the ray, Raja clavata...  相似文献   
82.
Three patients with progressive coccidioidomycosis were given preparations of transfer factor (TF). Adverse reactions to TF were minimal. Following TF administration two of these patients had prolonged clinical remissions in their coccidioidal disease. Cellular immune responses were sequentially evaluated by coccidioidininduced delayed-type skin tests, lymphocyte blast transformation and macrophage inhibition factor production (MIF). These three patients each exhibited different cellular immune patterns before and after TF administration. Two patients converted their coccidioidin skin tests, and one converted lymphocyte transformation response to coccidioidin. Also, TF apparently favorably affected the MIF response in all three patients.  相似文献   
83.
84.
85.
Summary The fluorescent antibody technique was used to study antigenic relationships betweenParacoccidioides loboi and other pathogenic fungi. The findings suggest thatP. loboi is more closely related antigenically to certainP. brasiliensis strains than to others and that it has antigens in common with the yeast form ofHistoplasma capsulatum, H. duboisii, Blastomyces dermatitidis, Candida albicans and also the mycelial form ofCoccidioides immitis. Serum globulins from 3 cases of keloidal blastomycosis were labelled with fluorescein isothiocyanate. These conjugates showed slight or no reactivity withP. loboi, the yeast forms ofP. brasiliensis, H. capsulatum, H. duboisii andB. dermatitidis, However, they stained brightlyC. albicans, serotypes A and B, the tissue form ofC. immitis and the yeast form ofSporotrichum schenckii. Adsorption of these reagents withC. albicans eliminated all staining except that forS. schenckii. These patients had no history of clinical sporotrichosis.Deceased. Last address: Fundacão Gonçalo Moniz, Salvador, Bahia, Brazil. Requests for reprints should be sent to Dr.William Kaplan.Dr.Miranda is in private practice in Rio de Janeiro, Brazil.  相似文献   
86.
87.
88.
89.
90.
Of four species studied, tolerance of extreme temperatures in greatest in Spirorbis pagenstecheri (which extends highest on the shore) and least in S. corallinae (which always occurs immersed in water). The latter species breeds between May and August, the other three from May to October. S. borealis liberates its larvae mainly at the moon's quarters, but this fortnightly rhythm is less obvious in S. corallinae and not found in the other two species. S. corallinae differs from S. borealis in being slower to re-emerge after disturbance and in having a lesser breeding size, maximum size and life span. Growth in the laboratory is slower in S. tridentatus than in the other species. Growth of S. borealis under natural conditions is much faster in summer than in winter.  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