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   1004686篇
  免费   69589篇
  国内免费   2588篇
耳鼻咽喉   13022篇
儿科学   34483篇
妇产科学   28460篇
基础医学   145385篇
口腔科学   27745篇
临床医学   90427篇
内科学   193987篇
皮肤病学   22932篇
神经病学   79323篇
特种医学   38418篇
外国民族医学   305篇
外科学   149595篇
综合类   23743篇
一般理论   385篇
预防医学   77903篇
眼科学   22647篇
药学   71986篇
  19篇
中国医学   2034篇
肿瘤学   54064篇
  2018年   10586篇
  2017年   8269篇
  2016年   9415篇
  2015年   10600篇
  2014年   14425篇
  2013年   22001篇
  2012年   28982篇
  2011年   30824篇
  2010年   18487篇
  2009年   17435篇
  2008年   28790篇
  2007年   30460篇
  2006年   30960篇
  2005年   29638篇
  2004年   28924篇
  2003年   27796篇
  2002年   26814篇
  2001年   46923篇
  2000年   48034篇
  1999年   40263篇
  1998年   11179篇
  1997年   10096篇
  1996年   10160篇
  1995年   9775篇
  1994年   9090篇
  1993年   8480篇
  1992年   32248篇
  1991年   31458篇
  1990年   31009篇
  1989年   29874篇
  1988年   27167篇
  1987年   27325篇
  1986年   25435篇
  1985年   24602篇
  1984年   18398篇
  1983年   15515篇
  1982年   9288篇
  1981年   8375篇
  1979年   16859篇
  1978年   12217篇
  1977年   10314篇
  1976年   9754篇
  1975年   10178篇
  1974年   12317篇
  1973年   11843篇
  1972年   10884篇
  1971年   10113篇
  1970年   9375篇
  1969年   8724篇
  1968年   8104篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
95.
96.
An experimental study evaluating the contributions of graft composition (particulate vs. whole) and revascularization (immediate reanastomosis vs. delayed) to cervicofacial fat transplantation was conducted in rats. Distant (inguinal fat) grafts were bilaterally transplanted to a muscular bed in the cervicofacial region as a free flap (anastomosis to carotid and jugular vessels) or as a free graft (either particulate or whole). Postoperative assessment was made by comparison of pre- and post-operative weights and histologic examination of all specimens, and by acrylic microangiography in select animals of each group. The fat flaps exhibited minimal loss of tissue volume, and showed a normal histologic appearance of the adipocytes and extensive vascular elements within the grafts. Conversely, considerable volume loss occurred in both the particulate and whole fat grafts. Histologically, the free graft was characterized by cellular disruption, atrophic adipocytes, and areas of acellularity. Whole grafts had histologic evidence of vessels located primarily at the periphery, whereas particulate grafts had increased intragraft vessels. Only the fat flaps showed observable intragraft vasculature by microangiography. These findings suggest that reduction of fat grafts into smaller components, eg, by liposuction harvesting, does not improve graft survival or decrease posttransplant resorption.  相似文献   
97.
Zymosan-induced chemiluminescence was investigated in whole blood and in neutrophils: in both, the peak count was frequently elevated in Beh?et's disease, and was significantly higher than in healthy controls; similarly the peak time was shorter. There were more uncommon serotypes of Streptococcus sanguis in the oral flora of patients with Beh?et's disease. Common serotypes were present in the flora of healthy controls, but not in patients with the disease. The percentage of Strep. sanguis in the oral flora was significantly correlated with the level of chemiluminescence response. Thus infection with uncommon serotypes of Strep. sanguis may play a role in the aetiology of Beh?et's disease.  相似文献   
98.
Oral mucosal status and major salivary gland function   总被引:2,自引:0,他引:2  
Normal salivary function is considered to be critical for the maintenance of healthy oral mucosa. However, few studies have examined mucosal changes in patients with objectively documented salivary gland performance. In the present report, the mucosal status of 298 subjects being evaluated in a dry mouth clinic was assessed. A complete oral examination was performed and unstimulated and stimulated salivary samples were collected separately from the parotid and submandibular/sublingual glands. Data were analyzed according to diagnosis and salivary output after the assignment of an oral mucosal rating to each subject. In general, the mucosal surfaces were well preserved and infections were not seen. Patients evaluated for Sj?gren's syndrome and radiation-induced xerostomia had the lowest salivary gland performance but displayed a mucosal status similar to denture-wearing healthy subjects or patients with normal salivary flow who had idiopathic xerostomia. However, those patients with a total lack of salivary flow rarely had normal-appearing oral mucosa. These results confirm a role for saliva in oral mucosal preservation and also suggest that other factors may act to maintain oral mucosal integrity.  相似文献   
99.
100.
A total of 51 adult subjects participated in a three-period crossover trial to test plaque-removal effectiveness of a prebrushing mouthrinse. Subjects refrained from brushing to allow plaque to accumulate for 24 hours before the test. The accumulated plaque was graded using Turesky's method. The subjects then used one of three treatment regimens, were retested for accumulated plaque and regraded. The three treatments tested were a commercial prebrushing mouthrinse and no toothbrushing; a commercial prebrushing mouthrinse and brushing with a dentifrice for 30 seconds; a prebrushing water rinse and brushing with a dentifrice for 30 seconds. The analysis of the data found that both groups that brushed removed significantly more plaque than the group that did not brush. However, both the prebrushing rinse group and the water rinse group achieved the same amount of plaque removal through 30 seconds of toothbrushing with a dentifrice.  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