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   2155篇
  免费   70篇
  国内免费   6篇
耳鼻咽喉   23篇
儿科学   18篇
妇产科学   7篇
基础医学   307篇
口腔科学   112篇
临床医学   185篇
内科学   445篇
皮肤病学   40篇
神经病学   387篇
特种医学   87篇
外科学   245篇
综合类   16篇
一般理论   1篇
预防医学   68篇
眼科学   19篇
药学   145篇
中国医学   2篇
肿瘤学   124篇
  2023年   9篇
  2021年   17篇
  2020年   19篇
  2019年   22篇
  2018年   47篇
  2017年   9篇
  2016年   32篇
  2015年   30篇
  2014年   60篇
  2013年   64篇
  2012年   137篇
  2011年   150篇
  2010年   89篇
  2009年   82篇
  2008年   133篇
  2007年   163篇
  2006年   165篇
  2005年   191篇
  2004年   148篇
  2003年   166篇
  2002年   141篇
  2001年   38篇
  2000年   27篇
  1999年   28篇
  1998年   25篇
  1997年   33篇
  1996年   25篇
  1995年   21篇
  1994年   16篇
  1993年   23篇
  1992年   12篇
  1991年   4篇
  1990年   12篇
  1989年   4篇
  1988年   7篇
  1987年   14篇
  1986年   7篇
  1985年   3篇
  1984年   3篇
  1983年   7篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1978年   2篇
  1977年   5篇
  1976年   4篇
  1975年   4篇
  1974年   5篇
  1970年   3篇
排序方式: 共有2231条查询结果,搜索用时 31 毫秒
1.
Zumel-Marne  Angela  Kundi  Michael  Castaño-Vinyals  Gemma  Alguacil  Juan  Petridou  Eleni Th  Georgakis  Marios K.  Morales-Suárez-Varela  Maria  Sadetzki  Siegal  Piro  Sara  Nagrani  Rajini  Filippini  Graziella  Hutter  Hans-Peter  Dikshit  Rajesh  Woehrer  Adelheid  Maule  Milena  Weinmann  Tobias  Krewski  Daniel  ′t Mannetje  Andrea  Momoli  Franco  Lacour  Brigitte  Mattioli  Stefano  Spinelli  John J.  Ritvo  Paul  Remen  Thomas  Kojimahara  Noriko  Eng  Amanda  Thurston  Angela  Lim  Hyungryul  Ha  Mina  Yamaguchi  Naohito  Mohipp  Charmaine  Bouka  Evdoxia  Eastman  Chelsea  Vermeulen  Roel  Kromhout  Hans  Cardis  Elisabeth 《Journal of neuro-oncology》2020,147(2):427-440
Journal of Neuro-Oncology - We used data from MOBI-Kids, a 14-country international collaborative case–control study of brain tumors (BTs), to study clinical characteristics of the tumors in...  相似文献   
2.
3.
4.
Since March 2020, the COVID-19 pandemic has led to the need to re-think the delivery of services to patients with chronic dysimmune neuropathies. Telephone/video consultations have become widespread but have compounded concerns about objective evaluation. Therapeutic decisions need, more than ever before, to be considered in the best interests of both patients, and society, while not denying function-preserving/restoring treatment. Immunoglobulin therapy and plasma exchange, for those treated outside of the home, expose patients to the hazards of hospital or outpatient infusion centers. Steroid therapy initiation and continuation pose increased infectious risk. Immunosuppressant therapy similarly becomes highly problematic, with the risks of treatment continuation enhanced by uncertainties regarding duration of the pandemic. The required processes necessitate considerable time and effort especially as resources and staff are re-deployed to face the pandemic, but are essential for protecting this group of patients and as an integral part of wider public health actions.  相似文献   
5.
6.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Hausärzte sind als Primärversorger für Patienten mit depressiven Störungen entscheidende Weichensteller...  相似文献   
7.

Purpose

Microvascular fibula flap surgery is a reliable and effective procedure for reconstructing the jaws after tumour surgery. This procedure allows the placement of dental implants after bone consolidation. This study was designed to evaluate the oral, functional, and aesthetic rehabilitation of tumour patients with immediate fibula transfer and dental implants and included assessment of diet, speech, and aesthetics.

Materials and methods

The study included 34 patients who underwent ablative tumour surgery and immediate jaw reconstruction using a fibula free flap with consecutive rehabilitation by dental implants. In total, 134 implants were inserted into the transferred fibula. The functional and aesthetic results were assessed using a questionnaire. Implant loss and oral excursion were compared with diet type, speech ability, functionality, and patient satisfaction.

Results

Of the 34 patients included in this study, 33 completed the questionnaire. Twenty-six patients (76%) could eat normally without the limitation of a hard or soft diet, 73% could speak intelligibly, and 31 rated the aesthetic result from good to excellent.

Conclusion

The fibula flap with the early application of endosseous implants allowed primary immediate reconstruction of the jaw, significantly leading to functional and aesthetic satisfaction in patients who underwent ablative tumour surgery.  相似文献   
8.
STATEMENT OF PROBLEM: The diagnostic value of radiographs for interproximal caries detection on nonrestored teeth is well investigated. However, little is known about the use of radiographs in the diagnosis of secondary caries localized at crown margins. PURPOSE: The aim of this study was to correlate clinical findings with regard to secondary caries with the findings of a radiographic evaluation. MATERIALS AND METHODS: One hundred randomly selected patients who underwent restorations with fixed prostheses and were exhibiting at least one secondary carious lesion were included in the study. A total of 820 restorations (test group, 730 interproximal surfaces of 365 single crowns and 910 interproximal surfaces of 455 fixed partial denture retainer crowns) and 1024 interproximal surfaces of 512 nonrestored teeth (control group) were investigated clinically, with the use of modified California Dental Association criteria, and radiographically for interproximal carious lesions. The extension of the lesions was rated to be initial (with no cavitation), early (with cavitation limited to orthodentin), or deep (with cavitation). The data were statistically analyzed for normal distribution, and the frequency of the findings was calculated in absolute numbers and as a percentage. Statistically significant differences were determined by use of the chi(2) test (P<.05). A linear regression model was applied for the correlation between the percentage of secondary caries and the duration of the crowns in situ. RESULTS: Secondary caries was diagnosed clinically in 11.2% of 1640 interproximal surfaces but only in 8.3% radiographically. In contrast, the frequency of interproximal carious lesions diagnosed clinically in nonrestored teeth increased with the use of radiographs from 3.3% to 4.1%. CONCLUSION: Within the limits of this study, the results confirm that radiographs improve the diagnostic sensitivity for interproximal caries in nonrestored teeth. However, for the diagnosis of secondary caries in crowned teeth, the clinical examination is more reliable than the radiographic evaluation.  相似文献   
9.
Over the last few decades, reconstructive surgery has shifted from a resection-oriented approach toward strategies focusing on repair and regeneration of tissues. As the main aim of maxillofacial reconstruction has been the restoration of bone form and function, surgeons used artificial tissue substitutes in the early decades of bone reconstruction. These artificial materials significantly improved the ability of surgeons to restore the form and, to some extent, the function of defective bones. Despite the fact that every artificial material has specific disadvantages, the use of biomaterials is a common treatment option in clinical practice even today. Due to the more detailed understanding that exists concerning transplantation of cells and tissues, autogenous grafts are the second mainstay in clinical practice. However, the main disadvantage of using autogenous grafts is donor site morbidity and donor shortage. Research is currently in progress into the use of cell-based approaches in reconstructive surgery, since cells are the driving elements for all repair and regeneration processes. Various cell populations have been reported on in the relevant literature. These cells can be classified according to differentiation capacity and the tissue from which they originated. In this review, unrestricted cells, multipotential progenitor cells, determined cells, and genetically modified cells are described systematically, and their advantages as well as limitations are discussed. (More than 50 references.)  相似文献   
10.
OBJECTIVE: The main objective was to compare the presence of interlayer gaps between 2 hybrid composites placed using a microlayer and a 2-layer technique. METHOD AND MATERIALS: Standardized Class 1 cavities were prepared in 40 extracted posterior teeth. Two resin composite materials were used. The control group, group A, consisted of samples of the materials extruded out of the manufacturers' syringes. Group B consisted of 10 teeth restored using 2 layers per restoration. Group C consisted of 30 teeth restored using 6 microlayers per restoration. A scanning electron microscope was used to detect voids in the samples. RESULTS: Round, well-defined voids were found in 85% to 100% of the samples within the bulks of the resin composite materials only. A statistically significant relationship between the type of composite and presence of bubbles (Fisher exact test, P = .04) was found among the 2-layer technique group. No statistically significant difference (Fisher exact test, P = .48) was found among the microlayer technique group. Irregular interlayer gaps were found in 5% to 15% of specimens within areas between bulks of composite, as detected by an electron microscope based on the different densities of the bulks of composite and the interlayer areas. No such statistically significant relationship was found (Fisher exact, P = .62) among the study groups. CONCLUSIONS: Voids are routinely found in bulks of composite materials. Higher incidences of interlayer gaps in the 2-layer samples suggest that the use of a microlayering technique may result in fewer gaps.  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