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   296127篇
  免费   17590篇
  国内免费   413篇
耳鼻咽喉   4207篇
儿科学   10316篇
妇产科学   10249篇
基础医学   45005篇
口腔科学   7511篇
临床医学   24148篇
内科学   55850篇
皮肤病学   6321篇
神经病学   21047篇
特种医学   11616篇
外国民族医学   43篇
外科学   46677篇
综合类   7762篇
现状与发展   1篇
一般理论   160篇
预防医学   19911篇
眼科学   6947篇
药学   20917篇
中国医学   787篇
肿瘤学   14655篇
  2018年   3625篇
  2017年   2656篇
  2016年   3079篇
  2015年   3491篇
  2014年   4589篇
  2013年   7214篇
  2012年   9081篇
  2011年   9464篇
  2010年   6140篇
  2009年   5557篇
  2008年   8701篇
  2007年   9556篇
  2006年   9380篇
  2005年   8986篇
  2004年   8691篇
  2003年   8192篇
  2002年   7794篇
  2001年   13338篇
  2000年   13670篇
  1999年   11436篇
  1998年   3030篇
  1997年   2796篇
  1996年   2639篇
  1995年   2549篇
  1994年   2346篇
  1992年   8322篇
  1991年   8459篇
  1990年   8273篇
  1989年   8080篇
  1988年   7322篇
  1987年   7073篇
  1986年   6722篇
  1985年   6518篇
  1984年   4761篇
  1983年   4118篇
  1982年   2469篇
  1979年   4428篇
  1978年   3228篇
  1977年   2731篇
  1976年   2503篇
  1975年   2833篇
  1974年   3353篇
  1973年   3362篇
  1972年   3119篇
  1971年   2948篇
  1970年   2838篇
  1969年   2581篇
  1968年   2538篇
  1967年   2373篇
  1966年   2264篇
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
961.
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed.  相似文献   
962.
The results of treatment of 107 young and middle aged sufferers with mild craniocerebral trauma have been analysed. The regimen for use of hyperbaric oxygenation contributing to normalization of general cerebral, focal disorders in high nervous and psychic activity, prevention of certain posttraumatic complications has been developed.  相似文献   
963.
The authors report on 14 patients with epidermoid carcinoma of the glottic region, classified T1, T2 and T3, operated upon by a hemilaryngectomy (9 cases) with reconstruction using a Plathysma myocutaneous flap. The oncological results over a follow-up period of 1 to 6 years and the functional results are analyzed. The authors conclude that this method does not compromise the carcinological result and provides a good functional result with low ratings for complications, with in addition an adequate support for the organ, favouring increased resections.  相似文献   
964.
The new diagnostic criteria of coeliac disease (CD) give more importance to serological markers. Immunoglobulin A antiendomysial antibodies (IgA-EmA) were determined in 138 sera from 79 coeliac children and the antibody levels compared to IgG and IgA antigliadin antibodies (IgG-AGA, IgA-AGA) in the sera. The assessment was also carried out in 29 children with other gastrointestinal diseases, 29 with non-gastrointestinal diseases and 35 healthy children. The IgA-EmA had a 91.4% specificity and a 88.4% sensitivity for active CD. The corresponding figures were 89.8% and 64.4% for IgA-AGA and 73.7% and 86.2% for IgG-AGA, respectively. The results of IgA-EmA determinations were concordant with the intestinal biopsy findings in 90% of cases, versus 80% for IgA-AGA and 83% for IgG-AGA. In most of the discordant cases the biopsy showed only minor changes, making the classification difficult. All patients with positive IgA2-EmA also had positive IgA1 EmA antibodies. IgA-EmA are an excellent serological marker of CD activity in children and they are useful to decrease the number of intestinal biopsies which are needed to confirm the diagnosis in coeliac patients.  相似文献   
965.
A prospective study of school girls in a mixed Nigerian population revealed that the mean menarcheal age was 13.98 +/- 1.30 years. The mean menarcheal age was influenced by the social class of the parents, being higher in the lower social class, there were considerable variations in the biologic measurements (height, weight and body mass index) among girls who attained menarche.  相似文献   
966.
Assessment of attitudes amongst health care professionals to suicide prevention reveals a considerable degree of doubt with regards to its feasibility and appropriateness. The various professional groups may vary considerably in the degree of negative attitudes which they exhibit. Such findings suggest that there is an urgent need to ensure that health care professionals are fully informed about the key facts concerning suicide and preventive strategies. Key elements of clinical practice and service organization with regards to suicide prevention are discussed.  相似文献   
967.
968.
969.
Polyester-crystic cast was observed to reach the peritubular capillary plexus following injection in sheep kidneys. Microvascular structures in this region are also reported in this study. Glomeruli were found to vary in size and shape. Diameters of afferent arterioles were larger than those of efferent arterioles. The glomerulus is supplied by more than one afferent arteriole, and in some regions, the blood in afferent arterioles joins collateral circulation via the intercapillary plexus. Morphological properties at the end of the peritubular capillary plexus were found to be remarkably significant.  相似文献   
970.
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