全文获取类型
收费全文 | 64127篇 |
免费 | 4713篇 |
国内免费 | 358篇 |
专业分类
耳鼻咽喉 | 646篇 |
儿科学 | 1611篇 |
妇产科学 | 1546篇 |
基础医学 | 7925篇 |
口腔科学 | 1548篇 |
临床医学 | 6501篇 |
内科学 | 14522篇 |
皮肤病学 | 819篇 |
神经病学 | 5029篇 |
特种医学 | 1931篇 |
外国民族医学 | 2篇 |
外科学 | 9800篇 |
综合类 | 1172篇 |
现状与发展 | 1篇 |
一般理论 | 103篇 |
预防医学 | 5302篇 |
眼科学 | 1886篇 |
药学 | 4524篇 |
1篇 | |
中国医学 | 194篇 |
肿瘤学 | 4135篇 |
出版年
2023年 | 313篇 |
2022年 | 517篇 |
2021年 | 1225篇 |
2020年 | 783篇 |
2019年 | 1053篇 |
2018年 | 1272篇 |
2017年 | 898篇 |
2016年 | 1005篇 |
2015年 | 1177篇 |
2014年 | 1829篇 |
2013年 | 2853篇 |
2012年 | 3831篇 |
2011年 | 4146篇 |
2010年 | 2389篇 |
2009年 | 2217篇 |
2008年 | 4032篇 |
2007年 | 4219篇 |
2006年 | 4042篇 |
2005年 | 4137篇 |
2004年 | 3857篇 |
2003年 | 3467篇 |
2002年 | 3431篇 |
2001年 | 735篇 |
2000年 | 634篇 |
1999年 | 734篇 |
1998年 | 743篇 |
1997年 | 616篇 |
1996年 | 495篇 |
1995年 | 496篇 |
1994年 | 471篇 |
1993年 | 446篇 |
1992年 | 537篇 |
1991年 | 515篇 |
1990年 | 423篇 |
1989年 | 443篇 |
1988年 | 399篇 |
1987年 | 373篇 |
1986年 | 356篇 |
1985年 | 420篇 |
1984年 | 433篇 |
1983年 | 396篇 |
1982年 | 529篇 |
1981年 | 443篇 |
1980年 | 485篇 |
1979年 | 301篇 |
1978年 | 322篇 |
1977年 | 321篇 |
1976年 | 261篇 |
1975年 | 287篇 |
1974年 | 246篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Osteonecrosis of the jaws in patients with a history of receiving bisphosphonate therapy: strategies for prevention and early recognition 总被引:6,自引:0,他引:6
BACKGROUND: Bisphosphonates, inhibitors of osteoclasts, have been shown to alleviate many of the devastating consequences associated with metastatic bone disease. However, recent reports have shown that bisphosphonates may cause osteonecrosis of the jaws. Since the publication of these initial reports, the authors have treated several patients with osteonecrosis of the jaws who had a history of receiving bisphosphonate therapy. METHODS: The authors reviewed the medical records of patients who visited their clinic between September 2003 and December 2004 and who had osteonecrosis of the jaws and a history of having received bisphosphonate therapy but no irradiation to the head and neck. RESULTS: Eleven patients (four female and seven male) with a mean age of 69 years were included in this report. They had received bisphosphonate therapy for a mean duration of 34 months. Radiographic data showed loss of bone density at sites of osteonecrosis, and histologic examination demonstrated necrosis of bone without evidence of metastases. CONCLUSIONS AND CLINICAL IMPLICATIONS: Further research is required for better understanding of the role of bisphosphonates in the development of osteonecrosis of the jaws. Until more is known, the authors recommend that measures be taken to prevent osteonecrosis those at risk, including identifying patients with a history of having received bisphosphonate therapy before they undergo dental surgery. To help identify such patients, the authors propose the use of a screening questionnaire. When feasible, physicians should consult with their patients' general dentists or oral surgeons before patients begin bisphosphonate therapy. 相似文献
44.
Raymond P White Phoebus N Madianos Steven Offenbacher Ceib Phillips George H Blakey Richard H Haug Robert D Marciani 《Journal of oral and maxillofacial surgery》2002,60(11):1234-1240
PURPOSE: Our goal was to report the detection and levels of pathogenic bacteria in subgingival plaque samples taken from the distal of all second molars in 295 patients with asymptomatic third molars. PATIENTS AND METHODS: Data assessing oral health were collected from each of these healthy patients (ASA Classes I and II). Probing depth (PD), at 6 sites per tooth, including third molars, was obtained to determine periodontal status. Subgingival plaque samples were taken from the distal of all second molars before periodontal probing. The presence and levels of 11 bacterial species were determined using whole chromosomal DNA probes and checkerboard DNA-DNA hybridization. Detected bacterial species were grouped into clusters of periodontal pathogens designated as "red" or "orange" complex microorganisms as described by Socransky et al (J Clin Periodontal 25:134, 1998) who found an association of these specific microorganisms with periodontitis. RESULTS: As a group these relatively young patients were periodontally healthy. "Orange and red" complex microorganisms were detected at levels equal to or greater than 10(5) more often if patients had a PD equal to or greater than 5 mm with periodontal attachment loss at the distal of second molars or around third molars at their entry examination. In patients with no PD equal to or greater than 5 mm in the third molar region, "orange and red" complex microorganisms were detected at levels equal to or greater than 10(5) more frequently than would be anticipated in patients with little clinical evidence of periodontal disease. CONCLUSIONS: The clinical findings of increased periodontal PDs and periodontal attachment loss coupled with colonization of periodontal pathogens support the concept that clinical and microbial changes associated with the initiation of periodontitis may present first in the third molar region in young adults. 相似文献
45.
Haden NK Catalanotto FA Alexander CJ Bailit H Battrell A Broussard J Buchanan J Douglass CW Fox CE Glassman P Lugo RI George M Meyerowitz C Scott ER Yaple N Bresch J Gutman-Betts Z Luke GG Moss M Sinkford JC Weaver RG Valachovic RW;ADEA 《Journal of dental education》2003,67(5):563-583
Academic dental institutions are the fundamental underpinning of the nation's oral health. Education, research, and patient care are the cornerstones of academic dentistry that form the foundation upon which the dental profession rises to provide care to the public. The oral health status of Americans has improved dramatically over the past twenty-five to thirty years. In his 2000 report on oral health, the Surgeon General acknowledges the success of the dental profession in improving the oral health status of Americans over the past twenty-five years, but he also juxtaposes this success to profound and consequential disparities in the oral health of Americans. In 2002, the American Dental Education Association brought together an ADEA President's Commission of national experts to explore the roles and responsibilities of academic dental institutions in improving the oral health status of all Americans. They have issued this report and made a variety of policy recommendations, including a Statement of Position, to the 2003 ADEA House of Delegates. The commission's work will help guide ADEA in such areas as: identifying barriers to oral health care, providing guiding principles for academic dental institutions, anticipating workforce needs, and improving access through a diverse workforce and the types of oral health providers, including full utilization of allied dental professionals and collaborations with colleagues from medicine. 相似文献
46.
Charles B. Horton D.D.S. Helen M. Paulus D.M.D. George B. Pelleu Jr. Ph.D. Jerome J. Rudolph D.D.S. M.S.D. 《The Journal of prosthetic dentistry》1977,37(6):674-679
A study was conducted to determine the effectiveness of several commercial pastes in polishing the surfaces of composite resin material. Five samples of Concise composite resin contained within Plexiglas block holders were prepared using Mylar matrices. One block was disked only; three blocks were disked and polished, each with a different paste. The remaining block was the control. The surface roughness of all samples was measured with a stylus profile instrument. Five extracted teeth were prepared in the same manner with Concise composite resin and Mylar strip matrix. In each tooth, the surface was finished by disking only or by disking followed by polishing with one of three pastes. The fifth tooth was the control. The samples were examined by use of a scanning electron microscope. Quantitative evaluation of over-all computer data indicated that the smoothest surface was found immediately ater removal of the Mylar matrix and that pastes leave a rougher surface than is left with a disc. 相似文献
47.
48.
Albilia JB Lam DK Blanas N Clokie CM Sándor GK 《Journal (Canadian Dental Association)》2007,73(9):831-836
Scleroderma, or progressive systemic sclerosis (PSS), an autoimmune rheumatic condition affecting the connective tissues, has a profound impact on oral health. Common orofacial findings include xerostomia, gastroesophageal reflux disease and limited mouth opening. This review article describes scleroderma, or PSS, and its various manifestations. The features of CREST syndrome and morphea are reviewed. Concerns relevant to the prevention of dental disease and the safe delivery of dental care in this group of challenging patients are emphasized. 相似文献
49.
Raymond P White Steven Offenbacher George H Blakey Richard H Haug M Thomas Jacks Paige E Nance Ceib Phillips 《Journal of oral and maxillofacial surgery》2006,64(6):880-885
PURPOSE: To assess the association between risk markers of chronic oral inflammation and changes over time in periodontal probing depth (PD) in the third molar region, the distal of a second molar, or around a third molar. SUBJECTS AND METHODS: The data from these analyses are part of a study of subjects enrolled with 4 asymptomatic third molars with adjacent second molars in an institutional review board-approved longitudinal trial. Full-mouth periodontal probing was conducted at enrollment and follow-up. Enrollment levels of periodontal pathogens and gingival crevicular fluid inflammatory mediators were assayed as indicators of the degree of oral inflammation. Subjects were categorized as those who had at least a 2 mm change in periodontal PD between baseline and follow-up in the third molar region and those who did not. The relationship between aggregated subject baseline PD, levels of periodontal pathogens, and gingival crevicular fluid IL-1 beta, and the proportion of subjects with changes in PD >or=2 mm versus those with PD <2 mm were compared with Cochran-Mantel-Haenzsel statistics. Level of significance was set at 0.05. Risk assessment models for a change in PD >or=2 mm were developed using logistic regression analysis. RESULTS: Twenty-four percent of 254 subjects exhibited a change in PD from baseline to follow-up of >or=2 mm in the third molar region. Of these, 95% had a baseline PD of >or=4 mm. Both high (>or=10(5)) "orange" and "red" complex bacteria and PD of >or=4 mm detected at enrollment were significantly associated with a change in PD >or=2 mm. Odds of a change in PD >or=2 mm were increased if baseline pathogen levels were >or=10(5) or a PD of >or=4 mm was detected at enrollment. CONCLUSION: Our findings are consistent with chronic oral inflammation leading to a progression of periodontal disease in the third molar region. 相似文献
50.
Lichen planus is a dermatologic disease of unknown etiology characterized by keratotic plaques on the skin. Many patients also harbor white lesions of the oral mucosa. The literature contains numerous reports of lichen planus-like lesions evolving in conjunction with the administration of a variety of pharmacologic agents. It is difficult, if not impossible, to distinguish such lesions from one another. The present study evaluated the epithelial and basement membrane thickness, mast cells (intact cells and degranulated cells subepithelially) and the presence or absence of blood vessels in oral lichen planus and oral lichenoid lesions. The evaluation was done using the periodic acid-schiff (PAS) and toluidine blue staining techniques on 20 cases each of oral lichen planus and oral lichenoid lesions and 5 control specimens of normal buccal mucosa. The results showed an increased number of degranulated mast cells in areas of basement membrane degeneration, increased vascularity and increased PAS-positive basement membrane thickness in oral lichen planus as compared with oral lichenoid lesions. Reduced epithelial thickness was found in oral lichen planus. The present study emphasizes the importance of these parameters in differentiating oral lichen planus from oral lichenoid lesions using special staining techniques. 相似文献