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   20817篇
  免费   433篇
  国内免费   485篇
耳鼻咽喉   598篇
儿科学   1250篇
妇产科学   388篇
基础医学   2080篇
口腔科学   713篇
临床医学   1092篇
内科学   4934篇
皮肤病学   371篇
神经病学   1530篇
特种医学   559篇
外科学   3597篇
综合类   174篇
一般理论   10篇
预防医学   2056篇
眼科学   492篇
药学   1213篇
中国医学   200篇
肿瘤学   478篇
  2024年   4篇
  2023年   21篇
  2022年   52篇
  2021年   79篇
  2020年   82篇
  2019年   101篇
  2018年   125篇
  2017年   53篇
  2016年   122篇
  2015年   68篇
  2014年   106篇
  2013年   49篇
  2012年   1971篇
  2011年   2236篇
  2010年   497篇
  2009年   249篇
  2008年   1721篇
  2007年   1970篇
  2006年   1735篇
  2005年   1875篇
  2004年   1785篇
  2003年   1711篇
  2002年   1602篇
  2001年   1071篇
  2000年   1572篇
  1999年   719篇
  1998年   80篇
  1997年   13篇
  1996年   12篇
  1995年   14篇
  1994年   6篇
  1993年   4篇
  1992年   2篇
  1991年   4篇
  1990年   2篇
  1989年   2篇
  1988年   6篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1978年   1篇
  1976年   1篇
  1967年   1篇
  1966年   1篇
  1957年   1篇
  1942年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
A case of unusual hamartoma in a six-year-old otherwise healthy Brazilian girl is reported, with emphasis on histological and immunohistochemical features. A mass observed in the incisive papilla was detected whose appearance was similar to congenital epulis or fibroma. Histological findings showed interlacing fascicles of large spindle cells resembling smooth muscle cells. Immunohistochemical staining for desmin and for smooth-muscle actin was positive. The histological diagnosis was leiomyomatous hamartoma, based on clinical and microscopic observations.  相似文献   
2.
The use of the microscope as a tool for practising Medicine, especially in surgical specialisations, has been established for decades. The microscope was first used in OdontologyDentistry back to the 1970s and 1980s, and was introduced more widely (although it was still far from being in general use) during 1990s. The purpose of this article is to describe the main applications of the microscope in OdontologyDentistry today, as well as providing odontologists and stomatologists, whether specialists or in general practice, with information about microscopic OdontologyDentistry for better patient care. This work also gives particular importance to matters needed to achieve the necessary manual dexterity to work in a magnified operating field using a surgical microscope (SM).  相似文献   
3.
We operated on a 65-year-old woman and removed a solitary fibrous tumour from her oral mucosa. Microscopically we found marked atypia, abundant necrosis, increased number of mitotic figures (>4 in 10 high-power fields) and hypercellularity. The tumour cells were strongly stained for CD34. There has been no recurrence after 18 months.  相似文献   
4.
Unhealthy oral habits may be involved in the etiology of a malocclusion, since they may affect development of the orofacial region. There is little information on the habit of sucking the lower lip, to which practitioners attribute less clinical consequences. However, lower lip sucking is a harmful habit which appears frequently in children, especially during situations requiring increased attention and mental concentration. In patients presenting lower lip sucking, strong contractions of the lower lip's orbicular's muscle and the mentalis muscle, associated with hypertonicity of the upper lip caused by sucking, has to be balanced by lingual thrusting during the act of deglutition. A case is presented in which failure to identify the habit of lower lip sucking led to an atypical lesion on the tongue, caused by the tongue's impaction against the orthodontic appliance prescribed to correct a malocclusion. The recognition and elimination of an unhealthy habit is of great importance in diagnosis and the establishment of a treatment plan, so that undesirable complications can be avoided.  相似文献   
5.
6.
7.
8.
9.
10.
This study quantified microleakage in restorations made with three packable resin composites-Solitaire, SureFil and P60; one hybrid resin composite-Z250 and an amalgam-Dispersalloy, with or without the thermocycling process. Sixty sound, freshly extracted human molars were sectioned mesiodistally, creating buccal and lingual blocks. One hundred blocks with the flattest surface were selected. Cylindrical cavities with a diameter of 1.85 +/- 0.05 mm and a depth of 1.5 mm were prepared with a special diamond bur. The blocks were randomly assigned to 10 test groups (n = 10): five restorative materials and two thermal stress groups (thermocycled groups at 3,000 cycles at 5 degrees C and 55 degrees C with a dwell time of one minute at each temperature, or non-thermocycled). After the thermocycling test, the samples were immersed in 2% methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed by the Kruskal-Wallis test and the Mann Whitney test. For the non-thermocycled groups, the means (microg/ml) of microleakage were: Amalgam-4.279 (a); Solitaire-4.148 (ab); Z250-3.418 (abc); P60-3.184 (bc); SureFil-2.890 (c). For the thermocycled groups, the means were: Amalgam-7.572 (a); Solitaire-5.471 (a); Z250-4.330 (ab); P60-3.418 (bc) and SureFil-2.779 (c). Thermocycling analysis showed no significant differences between the thermocycled and non-thermocycled groups for each material tested. It was concluded that no test material prevented microleakage. Only SureFil and P60 showed leakage means significantly lower than amalgam, with SureFil showing lower leakage than Solitaire. P60 only showed lower leakage than Solitaire in the thermocycled groups and Z250 showed results similar to the others materials.  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