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   9581篇
  免费   76篇
  国内免费   7篇
耳鼻咽喉   289篇
儿科学   26篇
妇产科学   175篇
基础医学   1201篇
口腔科学   273篇
临床医学   1741篇
内科学   1047篇
皮肤病学   31篇
神经病学   165篇
特种医学   428篇
外科学   2222篇
综合类   9篇
预防医学   715篇
眼科学   216篇
药学   415篇
中国医学   1篇
肿瘤学   710篇
  2021年   19篇
  2020年   13篇
  2018年   30篇
  2017年   20篇
  2016年   25篇
  2015年   43篇
  2014年   73篇
  2013年   77篇
  2012年   349篇
  2011年   696篇
  2010年   350篇
  2009年   60篇
  2008年   495篇
  2007年   697篇
  2006年   713篇
  2005年   694篇
  2004年   811篇
  2003年   824篇
  2002年   879篇
  2001年   562篇
  2000年   742篇
  1999年   401篇
  1998年   117篇
  1993年   29篇
  1992年   37篇
  1991年   71篇
  1990年   74篇
  1989年   56篇
  1988年   61篇
  1987年   56篇
  1986年   43篇
  1985年   41篇
  1984年   40篇
  1983年   21篇
  1981年   11篇
  1979年   28篇
  1978年   17篇
  1977年   16篇
  1976年   12篇
  1975年   24篇
  1974年   30篇
  1973年   27篇
  1972年   21篇
  1971年   35篇
  1970年   34篇
  1969年   27篇
  1968年   23篇
  1967年   30篇
  1966年   12篇
  1965年   13篇
排序方式: 共有9664条查询结果,搜索用时 140 毫秒
1.
2.
Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.  相似文献   
3.
The healing of sluggishly postburn wounds after local electrostimulation (ES) with the use of current-conducting carbon tissue as the electrode was studied in 12 patients. Analysis of the clinical data which were corroborated by the results of morphological and biochemical studies confirmed the marked stimulating effect of local ES which facilitates successful taking of dermal autografts and healing of burn wounds. The obtained data are evidence that the method of ES through a current-conducting carbon tissue is promising in the complex of measures for local treatment of burn wounds.  相似文献   
4.
The ionizing radiation (150 Gy) extended the rat tail flick latency, decreased the pain-relief effects of morphine and opioids and enhanced the analgesic effect of clopheline. The radiation was followed by a decrease of vocalization threshold with a reduction of morphine- and clopheline-induced analgesia. Naloxone (0.1 mg/kg) eliminated the postradiation analgesia and did not change the hyperalgesic effect of the radiation.  相似文献   
5.
The article deals with the results of complex study of the effect of pulmonary insufficiency on intracardiac hemodynamics and function of the heart in the immediate and late-term periods after radical correction of Fallot's tetralogy. Answers are also given to questions concerning the expediency of the use and functional adequacy of a xeno-pericardial monocusp in the closure mechanism of the pulmonary artery valve. The study showed that massive pulmonary regurgitation has a negative effect on the functional condition of the right ventricle in late-term postoperative periods. Convincing data were obtained which allow a graft with a monocusp of a bull's pericardium to be recommended for further clinical use to prevent insufficiency of the pulmonary artery valve after radical correction of Fallot's tetralogy.  相似文献   
6.
7.
8.
9.
The authors have revealed a gradual development of venous hypertension and deceleration of the rate of venous blood flow in the damaged extremities in chronic obliterative arterial diseases. Decompensation of arterial hemodynamics is accompanied by the development of pronounced venous congestion with reduced venous pressure and tension. This may cause the incompetence of the deep venous valves.  相似文献   
10.
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