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   129797篇
  免费   20537篇
  国内免费   3046篇
耳鼻咽喉   2580篇
儿科学   2716篇
妇产科学   2450篇
基础医学   4876篇
口腔科学   5377篇
临床医学   28840篇
内科学   27352篇
皮肤病学   3372篇
神经病学   13215篇
特种医学   4320篇
外国民族医学   18篇
外科学   20219篇
综合类   4471篇
现状与发展   44篇
一般理论   1篇
预防医学   14744篇
眼科学   2727篇
药学   3576篇
  30篇
中国医学   1425篇
肿瘤学   11027篇
  2024年   1151篇
  2023年   5717篇
  2022年   2294篇
  2021年   3857篇
  2020年   6249篇
  2019年   2781篇
  2018年   7607篇
  2017年   7981篇
  2016年   8554篇
  2015年   8993篇
  2014年   11594篇
  2013年   13045篇
  2012年   5062篇
  2011年   5051篇
  2010年   7825篇
  2009年   9879篇
  2008年   4438篇
  2007年   3424篇
  2006年   4531篇
  2005年   3132篇
  2004年   2040篇
  2003年   1841篇
  2002年   1554篇
  2001年   2354篇
  2000年   1742篇
  1999年   2384篇
  1998年   2492篇
  1997年   2331篇
  1996年   2248篇
  1995年   1967篇
  1994年   1370篇
  1993年   1064篇
  1992年   941篇
  1991年   795篇
  1990年   644篇
  1989年   654篇
  1988年   616篇
  1987年   469篇
  1986年   418篇
  1985年   366篇
  1984年   271篇
  1983年   309篇
  1982年   232篇
  1981年   203篇
  1980年   122篇
  1979年   79篇
  1978年   119篇
  1977年   114篇
  1976年   83篇
  1974年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
On the educational aspects of esthetic stomatology]   总被引:1,自引:0,他引:1  
  相似文献   
52.
Objectives—To report our experience with temporalis myofascial flaps (TMF), describe the healing process of uncovered flaps in the mouth, and the histology of the repaired mucosa in the long term. Design—Prospective clinical and histological study. Subjects—36 patients who received a TMF over a 6.5 year period for serial assessment of the oral healing, 24 patients whose scars over the reconstructed area were assessed clinically, and 11 whose repaired mucosa was assessed histologically. Main outcome measures—To follow the clinical process of oral healing of the TMF and describe the repaired mucosa healed over the flap. Results—The uncovered TMF in the mouth healed gradually starting with an acute inflammatory phase, going through chronic inflammatory and proliferative phases with eventual epithelialisation of the oral mucosa. There were no major complications. The healed mucosa showed mild scarring in 70% of cases and the repaired mucosa had characteristic histological features that were distinct from the normal mucosa. Conclusion—The TMF is an extremely reliable and versatile flap for maxillofacial reconstruction which heals gradually with eventual coverage by mildly scarred repaired mucosa.  相似文献   
53.
The University of Sydney Dental School and more recently the Implant Centre have been treating patients with the Brånemark Osseointegration Implant System since 1981. Success depends on close cooperation between surgeon and prosthodontist. This paper describes specific prosthodontic treatment planning procedures based on a general knowledge of prosthodontics, and detailed methods for determining the position, length and alignments of the implants for a specific case by the use of radiographic and surgical templates.  相似文献   
54.
Objectives : This study compares the distributional and psychometric properties of the Geriatric Oral Health Assessment Index (GOHAI) in two samples of older adults, and examines how the self-perceived impact of oral disease, as measured by the GOHAI, varies in accordance with sample sociodemographic and health characteristics. Methods : Results are based on survey data from two samples of older men: a Medicare sample of patients using community physicians (n=799; mean age=74) and users of VA ambulatory health care (n=542; mean age=72). Results : The findings indicated significant differences between samples in mean GOHAI scores, with the VA sample exhibiting worse scores. A number of similarities in psychometric properties of the instrument across the two samples were found: high internal consistency reliability and similar inter-item and item-scale correlations. Factor analyses revealed somewhat different structures between the two samples, but explained similar amounts of variance; regression analyses indicated that income and self-rated oral health were significant predictors of GOHAI scores in both samples. Conclusions : The GOHAI exhibits satisfactory psychometric properties in both samples and is sensitive to sociodemographic differences among and between two samples of older men. Results suggest continued use of the GOHAI as an indicator of the impact of oral conditions on functioning and well-being in a variety of samples.  相似文献   
55.
To be truly useful, an index must be applicable universally without modification. The data presented in this article support the use of the standard DAI without modification to assess need for orthodontic treatment in both developing and industrialized countries. When students from Thailand, Australia, the German Democratic Republic, and Native Americans residing on Indian reservations rated the same 25 occlusal stimuli (photographs of dental configurations) for dental aesthetics, their ratings of these stimuli when arranged in rank order were highly correlated with those of US students. These 25 occlusal stimuli were a subset of the original 200 occlusal stimuli used in deriving the standard DAI regression equation. This article presents data indicating that when a Native American DAI was derived based on Native American ratings of the same 200 occlusal stimuli used in deriving the standard DAI, the Native American DAI and the standard DAI had the same ten components (orthodontic measurements) and strikingly similar regression coefficients (weights). Further analysis indicated that the two equations were sufficiently similar to justify using the standard DAI to obtain DAI scores on Native Americans and to estimate the relative social acceptability of their dental aesthetics. If ratings for dental aesthetics for the full set of 200 stimuli were available for each of the countries where only 25 were rated, we expect that, as in the case of Native Americans, a country-specific DAI, if computed, would be sufficiently similar to the standard DAI that no modification would be needed to allow use of the standard DAI in that country.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
56.
Investigation of the film thicknesses of four luting glass ionomer cements over a range of powder/liquid ratios indicated that the four cements had a similar potential film thickness of approximately 28 μm. Scanning electron-microscopic examination revealed that the glass ionomer cement powders contain a small number of relatively large particles and an abundance of very fine particles.  相似文献   
57.
The current study was undertaken to evaluate both maxillary and mandibular shape/size changes in children with Class III malocclusions, treated with a functional appliance (removable mandibular retractor). Nonconventional cephalometric methods (Bookstein's shape coordinate analysis, centroid size analysis, and tensor analysis) were applied to a maxillary triangle (T-FMN-A) and to a mandibular triangle (Co-Go-Pg). A group of 30 children with treated Class III malocclusions were compared with a matched group of 30 children with untreated Class III malocclusions. Treatment with the functional appliance produced a significantly increased growth of the maxilla, featuring a more downward and forward displacement of the region of point A and a significantly more upward and forward direction of condylar growth, leading to a “shrinkage” of total mandibular length. The biologic significance of some conventional cephalometric measurements used for the assessment of both maxillary and mandibular position and structure was tested.(Am J Orthod Dentofac Orthop 1997;112:622-33.)  相似文献   
58.
59.
Objectives: This study investigated correlates of dental care use in a representative sample of adults aged 70 and older throughout New England. Methods : Data were collected in in-home interviews and dental examinations. Following Andersen's behavioral model of health services utilization, varied measures of sociodemographic characteristics, dental health attitudes and practices, perceived need for care, and need objectively determined by clinical examination were included as potential correlates. Results : Recency of last visit was associated with positive attitudes toward dental care, regular dental hygiene, and having a usual source of care. Among dentulous subjects, recency of last visit also was related to sex and living arrangements. Frequency of visits for dentulous subjects was associated with the same variables, as well as with age and social class or education, in addition to need for care. For edentulous subjects, only a usual sourse of care and higher social class were associated with more frequent visits. Conclusions : Perceived need and attitudes toward dental care are important influences on use of care. Older persons must be convinced of the importance of regular dental care.  相似文献   
60.
As in all of medicine, there are basic assumptions underlying the present system of dental education and delivery. These basic assumptions are facing challenges due in part to the marked reduction in the incidence of caries and the development of more effective therapies. This current period of time is described as an era of true change, rather than the mere modification of existing technology. Changes are going to occur in a number of areas. The move will be from government to private, from small to large, from generalist to specialist. Since change is inevitable, one can learn about and prepare for the stress of change, the changes happening now, and how to adapt to change. Although many changes are beyond the individual's control, their occurrence may be beneficial.  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