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   22615篇
  免费   1940篇
  国内免费   135篇
耳鼻咽喉   230篇
儿科学   786篇
妇产科学   520篇
基础医学   2868篇
口腔科学   399篇
临床医学   2701篇
内科学   4456篇
皮肤病学   298篇
神经病学   1800篇
特种医学   977篇
外国民族医学   1篇
外科学   2867篇
综合类   558篇
一般理论   11篇
预防医学   2330篇
眼科学   861篇
药学   1572篇
中国医学   19篇
肿瘤学   1436篇
  2022年   142篇
  2021年   386篇
  2020年   219篇
  2019年   388篇
  2018年   448篇
  2017年   337篇
  2016年   358篇
  2015年   443篇
  2014年   589篇
  2013年   829篇
  2012年   1197篇
  2011年   1226篇
  2010年   694篇
  2009年   686篇
  2008年   1135篇
  2007年   1241篇
  2006年   1149篇
  2005年   1080篇
  2004年   1079篇
  2003年   1010篇
  2002年   977篇
  2001年   559篇
  2000年   579篇
  1999年   519篇
  1998年   279篇
  1997年   266篇
  1996年   217篇
  1995年   235篇
  1994年   219篇
  1993年   232篇
  1992年   407篇
  1991年   423篇
  1990年   402篇
  1989年   404篇
  1988年   351篇
  1987年   332篇
  1986年   339篇
  1985年   323篇
  1984年   249篇
  1983年   196篇
  1982年   161篇
  1981年   138篇
  1980年   145篇
  1979年   183篇
  1978年   145篇
  1977年   147篇
  1976年   117篇
  1974年   134篇
  1973年   137篇
  1971年   118篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Familial expansile osteolysis is a rare and possibly unique form of hereditary bone dysplasia with dental manifestations that has affected 42 members of a Northern Ireland family for five generations. Twenty-seven family members, aged 3 to 60 years, were examined clinically and radiographically, and it was found that cervical and/or apical root resorption is an early manifestation of the dysplasia. Of the 20 family members with skeletal manifestations of familial expansile osteolysis, 16 showed root resorption. Root resorption may therefore be a good prognosticator for later bone involvement.  相似文献   
12.
Supernumerary teeth   总被引:2,自引:0,他引:2  
L Mitchell 《Dental update》1989,16(2):65-6, 68-9
  相似文献   
13.
This report evaluates the impact of two dentin bonding techniques on microleakage of Class V restorations bonded with three new dentin bonding systems. Forty-eight extracted human premolar and molar teeth were randomly assigned to four groups for bonding with EBS Bonding System (ESPE, Seefeld, Germany); Syntac Single-Component (Ivoclar-Vivadent, Schaan, Liechtenstein); Scotchbond 1 (3M Dental Products, St. Paul, Minnesota); and a control, Prime and Bond 2.1 (Dentsply, DeTrey, Konstanz, Germany). Cavities were cut in both the buccal and lingual surfaces. The coronal half of each preparation was in enamel, and the gingival half was in cementum or dentin. The cavities were restored with composite after the application of dentin bonding agents, using two different drying techniques for each material. The teeth were stored in distilled water for 6 days at 37 degrees C and then thermocycled. The restorations were examined microscopically for leakage, using Procion brilliant red as a marker. All groups showed microleakage at both the enamel and dentin margins. At the gingival margin, there was no significant difference between any of the experimental materials and the control for either wet bonding (Kruskal-Wallis: p = .8920) or dry bonding (Kruskal-Wallis: p .9973); or between the two techniques for each material (Mann-Whitney U in all cases p > .05). Scanning electron microscopic examination confirmed that the zones of microleakage, as indicated by dye penetration, were principally resincohesive failures within the collagen-rich hybrid layer. Three water-based bonding agents were unable to prevent microleakage at either the enamel or dentin margins of Class V cavities regardless of which bonding technique was employed. All systems behaved equally.  相似文献   
14.
PURPOSE: An undetermined number of patients with temporomandibular joint (TMJ) symptoms have been treated with intra-articular disc implants composed of Teflon ethylene/propylene or Teflon polytetrafluoroethylene and aluminum oxide (Proplast-Teflon; Vitek, Houston, TX). These implants have shown the potential to fragment in situ resulting in nonbiodegradable particles that stimulate a giant cell reaction and lead to degeneration of local structures, pain, and limitation of mandibular opening. We examined the possible relationship between TMJ implants and persistent pain, responses to sensory stimuli, quality of life, and systemic immune dysfunction. PATIENTS AND METHODS: This case series (32 patients) were referred from university-based orofacial pain centers and private practices from across the United States. Laboratory and clinical assessments evaluated orofacial pain symptoms, neurologic function, clinical signs and symptoms of rheumatologic disease, physical function, systemic measures of immune function, and behavioral measures. RESULTS: We found that TMJ implant patients appeared to have altered sensitivity to sensory stimuli, a higher number of tender points with a diagnosis of fibromyalgia, increased self-report of chemical sensitivity, higher psychologic distress and significantly lower functional ability. Systemic illness or autoimmune disease was not evident in this series of TMJ implant patients. CONCLUSIONS: Significant problems were noted on clinical assessment of TMJ implant patients. This is a US government work. There are no restrictions on its use.  相似文献   
15.
African-American, Hispanic and Native-American/Alaskan Native dental students and professionals are often referred to as underrepresented minorities (URMs) because of their poor representation in the profession compared to their proportion in the U.S. population. Disparities in oral health services may, in part, be attributable to minority and economically disadvantaged patients' lack of confidence in the dental profession's ability to provide care in a culturally sensitive manner. Increasing diversity within the oral health workforce is one way to address this perception. However, an effective remedy will require all oral health professionals to devote additional attention to diversity and cultural competency issues.  相似文献   
16.
17.
This study compared the mean loads and modes of failure of teeth restored with all-ceramic crowns (ACCs) cemented with dual-cured (RelyX ARC; 3M ESPE) or light-cured (RelyX Veneer; 3M ESPE) luting cements. Clinically, there are advantages of light-cured cements over the recommended dual-cured cements, namely increased working time, improved handling, colour stability, and a homogenous mix. Forty, sound, extracted, human, premolar teeth underwent a standardized preparation for ACCs. IPS Empress (Ivoclar-Vivadent) crowns of standard dimensions were fabricated and 20 were cemented with each cement. The crowns were stored for 1 or 30 d in water and subjected to a compressive load to failure at 0.017 mm s−1. There were no significant differences in loads at failure, between each cement group, at each storage period, and there were no significant differences in loads at failure, for each cement, at 1 and 30 d of storage. There were also no significant differences in modes of failure between each cement group. Before recommending light-cured cement as an alternative to dual-cured cement for the cementation of all-ceramic crowns, further research is required to establish the depth of ceramic at which light-cured lutes fail to polymerize completely.  相似文献   
18.
19.
A survey in 1983 showed that 16% of general dental practitioners in the Lothian Region wore operating gloves when treating patients; 9% wore them continually and 7% only when performing dento-alveolar surgery. Twelve per cent replied that they would not consider wearing operating gloves and 72% stated that they might consider their use. A similar survey has now been completed 5 years later, involving practitioners in the Lothian and Borders regions. This shows that 163 (97%) of the 168 practitioners who replied now wear operating gloves; 51% restrict their use to the treatment of 'potentially infectious patients' and dento-alveolar surgery; 46% wear them continually. The main objections given to wearing gloves continually were loss of tactile sensation (67%) and cost (13%). The most difficult task to perform wearing gloves was root canal therapy (56%). The majority of practitioners (84%) believed that gloves reduced the dangers of cross-infection. The methods stated to be available for instrument sterilisation in 99.5% of practices were acceptable. This paper proposes that to eliminate cross-infection and protect the dental practitioner, operating gloves should be worn when treating all patients.  相似文献   
20.
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