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   2678篇
  免费   255篇
  国内免费   39篇
耳鼻咽喉   34篇
儿科学   116篇
妇产科学   78篇
基础医学   344篇
口腔科学   106篇
临床医学   329篇
内科学   508篇
皮肤病学   61篇
神经病学   178篇
特种医学   264篇
外科学   349篇
综合类   76篇
一般理论   6篇
预防医学   211篇
眼科学   62篇
药学   134篇
中国医学   9篇
肿瘤学   107篇
  2021年   31篇
  2020年   15篇
  2019年   37篇
  2018年   45篇
  2017年   30篇
  2016年   43篇
  2015年   45篇
  2014年   47篇
  2013年   98篇
  2012年   106篇
  2011年   105篇
  2010年   108篇
  2009年   79篇
  2008年   102篇
  2007年   98篇
  2006年   95篇
  2005年   122篇
  2004年   114篇
  2003年   95篇
  2002年   101篇
  2001年   66篇
  2000年   67篇
  1999年   63篇
  1998年   72篇
  1997年   67篇
  1996年   72篇
  1995年   57篇
  1994年   57篇
  1993年   51篇
  1992年   62篇
  1991年   60篇
  1990年   43篇
  1989年   58篇
  1988年   87篇
  1987年   46篇
  1986年   49篇
  1985年   52篇
  1984年   34篇
  1983年   35篇
  1982年   22篇
  1981年   18篇
  1980年   27篇
  1979年   25篇
  1978年   21篇
  1977年   15篇
  1976年   24篇
  1975年   17篇
  1974年   16篇
  1972年   20篇
  1966年   13篇
排序方式: 共有2972条查询结果,搜索用时 15 毫秒
1.
2.
据一位经验丰富的激光外科医师说,通常所认为激光能够毫无损伤去除毛发、文身和胎记的观念是错误和有害的. C.B. Zachary医师是旧金山加利福尼亚大学皮肤外科和激光中心的临床教授和主任,他认为在医疗机构中,激光只能由经验丰富的护士和技师在皮肤科医师或其他经过相应训练的内科医师监督下实施.  相似文献   
3.
BACKGROUND: Vitiligo is the most common pigmentary disorder with a global incidence from 0.1% to 2% in different geographical areas. Histopathology and histochemistry have shown the reduction of melanocytes in achromic patches, but microscopic changes of lesional and non-lesional skin are still not completely understood. Reflectance confocal microscopy (RCM), based on the different light reflectance index of cutaneous structures, allowed in vivo, en face microscopic evaluation of superficial skin layers with a resolution similar to skin histology. AIM: The purpose of this study was to evaluate RCM features of lesional and non-lesional skin of vitiligo patients. Moreover, re-pigmented areas were taken into consideration in order to evaluate melanocyte response to ultraviolet B (UVB) radiation. SUBJECTS AND METHODS: Sixteen patients of different phototypes affected by active non-segmental vitiligo and 10 controls were enrolled in the study. In vivo skin imaging was done using a commercially available RCM (Lucid, Vivascope 1500. Re-pigmented areas from 6 to 16 patients (after UVB narrow-band therapy) were also examined. RESULTS: Vitiligo lesions showed the disappearance of the bright rings normally seen at the dermo-epidermal junction. Moreover, non-lesional skin of vitiligo patients showed unexpected changes as the presence of half-rings or scalloped border-like features of the bright papillary rings. In re-pigmented areas after UVB narrow band therapy, the presence of activated, dendritic melanocytes was seen. CONCLUSIONS: Considering our results, and following further studies, RCM clinical applications could be used in the therapeutic monitoring and evaluation of the evolution of vitiligo.  相似文献   
4.
5.
Abstract: It has been hypothesized that pineal structure and function might differ between temperate zone and tropical species of mammals because of lower amplitudes of seasonal change in photoperiod and, in some areas, less seasonal climatic variation. Anoura geoffroyi produce a single offspring in November or December of each year on the Caribbean island of Trinidad, at 10°N latitude in the deep tropics. Previous work has shown that this population lacks reproductive responses to photoperiod, and must be enforcing seasonal breeding using a non-photoperiodic cue. Anoura geoffroyi have a minute, thin, and rod-like pineal gland. Throughout much of its length, the pineal courses irregularly within the ventrolateral wall of the great cerebral vein. This intimate relationship may have functional implications. Despite having a very small pineal gland, this species produced a nocturnal rise in serum melatonin. Serum melatonin levels in most individuals were below or near undetectable levels during the light period and rose to a peak averaging 100 pg/ml in the last third of the dark period. Our results indicate that, although the pineal gland of A. geoffroyi is extremely small, serum melatonin levels are comparable to those of other mammals.  相似文献   
6.
7.
8.
9.
10.
In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.  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