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   753篇
  免费   51篇
  国内免费   16篇
耳鼻咽喉   3篇
儿科学   53篇
妇产科学   2篇
基础医学   61篇
口腔科学   8篇
临床医学   76篇
内科学   163篇
皮肤病学   9篇
神经病学   40篇
特种医学   228篇
外科学   55篇
综合类   34篇
一般理论   1篇
预防医学   40篇
眼科学   5篇
药学   11篇
中国医学   1篇
肿瘤学   30篇
  2022年   2篇
  2021年   11篇
  2020年   10篇
  2019年   2篇
  2018年   5篇
  2017年   7篇
  2016年   11篇
  2015年   10篇
  2014年   5篇
  2013年   13篇
  2012年   10篇
  2011年   14篇
  2010年   21篇
  2009年   28篇
  2008年   13篇
  2007年   24篇
  2006年   16篇
  2005年   21篇
  2004年   10篇
  2003年   23篇
  2002年   16篇
  2001年   10篇
  2000年   10篇
  1999年   23篇
  1998年   47篇
  1997年   52篇
  1996年   40篇
  1995年   24篇
  1994年   40篇
  1993年   25篇
  1992年   12篇
  1991年   13篇
  1990年   9篇
  1989年   34篇
  1988年   21篇
  1987年   20篇
  1986年   26篇
  1985年   17篇
  1984年   17篇
  1983年   12篇
  1982年   13篇
  1981年   24篇
  1980年   6篇
  1979年   5篇
  1978年   9篇
  1977年   10篇
  1976年   11篇
  1975年   10篇
  1936年   2篇
  1934年   1篇
排序方式: 共有820条查询结果,搜索用时 10 毫秒
91.
92.
Adult dogs maintained on an artificial, balanced ration adequate in all dietary essentials as far as is known except water-soluble, heat-stable vitamin B2 (G) developed, after a sufficient time, a slowly progressive disease characterized by loss of weight, persistent vomiting and diarrhea, and marked muscular weakness, which ended fatally in from 200 to over 300 days. The clinical features of this condition, as pointed out in the discussion, are quite different from those characterizing the canine disease known as black tongue. The anatomic changes in this condition consist of marked demyelination of the peripheral nerves, including the vagus; degeneration of the medullary sheaths and replacement by gliosis of the posterior columns of the spinal cord, particularly the fasciculi graciles; degeneration of the medullary sheaths of the posterior and less often of the anterior nerve roots of the cord; occasionally slight degenerative changes in most of the other fiber tracts of the cord. Attention is called to the fact that degenerative lesions in the central nervous system similar or identical with these have frequently been described in pellagra in man.  相似文献   
93.
With increasing budgetary restraints on the health system, it is apparent that the main contribution that radiology departments can make to significant cost reduction in hospitals is to decrease the length of time between requesting an X-ray examination and receiving the report (and images). Digital radiography (DR) was introduced into the Radiology Department at the Royal Adelaide Hospital as a pilot project to research the cost–benefits and efficiency of the system, and to determine future directions for planning a digital department. The business plan developed prior to implementation of this pilot project predicted a saving of one bed-day per inpatient when a fully digital department with a picture archiving and communication system (PACS) is installed. This initial study comparing DR and conventional radiography (convR) provides baseline data and shows encouraging results for more rapid transmission of reports to clinicians.  相似文献   
94.
95.
96.
The Kheda project experience has shown that bio-environmentalcontrol of malaria is feasible, cost effective and ecologicallysound. It clearly brings out the need to consider health issuesat the planning stage of all developments. Bio-environmentalcontrol of malaria is suggested as the first line of attackfor the control of mosquitoes, malaria and other mosquito-bornediseases. Insecticides may be reserved for short-term use. Thiswill enable judicious and selective use of insecticides in solelyepidemic situations. The growing problem of resistance to insecticidesin mosquitoes as well as environmental pollution, can then besolved on a long term basis.  相似文献   
97.
98.
99.
Rholl  KS; Lee  JK; Ling  D; Sicard  GA; Griffith  RC; Freeman  M 《Radiology》1986,160(1):113-117
Findings of magnetic resonance (MR) imaging in acute renal rejection and acute tubular necrosis (ATN) were studied in dogs. On T1-weighted images, corticomedullary differentiation was absent in kidneys undergoing acute rejection. The loss of corticomedullary differentiation in these kidneys was secondary to a decrease in the relative signal intensity of the cortex, indicating prolongation of the T1 relaxation time of the cortex. In contrast, corticomedullary differentiation was preserved on T1-weighted images of autotransplanted kidneys and kidneys with ATN. MR imaging findings correlated with changes in water content in these three groups of kidneys. Kidneys undergoing acute rejection showed a marked increase in water content compared with kidneys in the other two groups. No change in fat content was found in any group.  相似文献   
100.
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