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   4295篇
  免费   224篇
  国内免费   47篇
耳鼻咽喉   84篇
儿科学   119篇
妇产科学   53篇
基础医学   491篇
口腔科学   471篇
临床医学   322篇
内科学   997篇
皮肤病学   201篇
神经病学   252篇
特种医学   254篇
外科学   520篇
综合类   43篇
一般理论   1篇
预防医学   371篇
眼科学   28篇
药学   222篇
中国医学   25篇
肿瘤学   112篇
  2023年   34篇
  2022年   52篇
  2021年   106篇
  2020年   88篇
  2019年   106篇
  2018年   123篇
  2017年   76篇
  2016年   110篇
  2015年   123篇
  2014年   165篇
  2013年   212篇
  2012年   231篇
  2011年   297篇
  2010年   217篇
  2009年   171篇
  2008年   206篇
  2007年   206篇
  2006年   163篇
  2005年   176篇
  2004年   137篇
  2003年   95篇
  2002年   87篇
  2001年   66篇
  2000年   76篇
  1999年   75篇
  1998年   94篇
  1997年   83篇
  1996年   83篇
  1995年   56篇
  1994年   69篇
  1993年   60篇
  1992年   30篇
  1991年   30篇
  1990年   42篇
  1989年   58篇
  1988年   52篇
  1987年   48篇
  1986年   42篇
  1985年   40篇
  1984年   33篇
  1983年   23篇
  1982年   31篇
  1981年   26篇
  1980年   16篇
  1979年   24篇
  1978年   16篇
  1977年   19篇
  1976年   18篇
  1973年   18篇
  1972年   21篇
排序方式: 共有4566条查询结果,搜索用时 15 毫秒
61.
To describe a new molar-incisor hypomineralization (MIH) severity scoring system (MIH-SSS) that focuses on the defects’ severity and to assess the sy  相似文献   
62.
Clinical Oral Investigations - The aim of this study was to investigate the effects of collagen cross-linking agents on nanomechanical and bonding properties of eroded dentin (ED), 24 h...  相似文献   
63.
64.
Summary We have presented an unusual case of benign lymphoid hyperplasia, which manifested as a cecal deformity in a 15-year-old boy. The clinical manifestation may have been related to partial occlusion of the appendiceal orifice. In future cases of benign lymphoid hyperplasia, colonoscopy may be diagnostic, and if it is used for continuing observation, may avert unnecessary surgical procedures in children and young adults.  相似文献   
65.
66.

Background

This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols.

Material and Methods

Forty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent.

Results

The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p<0.001). No significant differences were detected between implant designs for each drilling technique (p>0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p<0.03) only, but not for those placed in the 3.75 mm drilling sites (p>0.32).

Conclusions

Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed. Key words: Histomorphometry, biomechanical, in vivo, initial stability, insertion torque, osseointegration.  相似文献   
67.
68.
(1) Aim: This study aims to analyze the in vitro infiltration of a silicate root canal sealer into dentinal tubules after using different endodontic irrigating solutions. (2) Methods: Twenty-nine teeth with single roots were separated into three groups according to the final irrigation protocol: G1 n = 10) = 17% EDTA (ethylenediaminetetraacetic acid) + 3.0% sodium hypochlorite (NaOCl), G2 (n = 10) = 17% EDTA + 2.0% chlorhexidine and G3 (Control group, n = 9) = 17% EDTA + saline solution. Root canals were filled using cold lateral compaction technique with MTA Fillapex sealer and gutta-percha. The sealer was labeled with rhodamine B. The teeth were segmented at the middle and third apical sections, which were visualized using 10× confocal laser microscopy to determine the sealer penetration percentage. (3) Results: In the apical section, no statistically significant differences were found between the groups regarding sealer penetration. In the middle section, Group 1 obtained the highest percentage, and Group 2 the lowest (p = 0.004). Group 1 also presented statistically significant differences in the Control Group (p = 0.031) and had close sealer penetration values. Meanwhile, the Control Group (p = 0.023) and Group 2 (p = 0.029) revealed a significant decrease of sealer penetration between the apical and middle sections. (4) Conclusion: The obtained results support that final irrigation with NaOCl promoted similar sealer penetration in the apical and middle sections. On the other hand, a significant decrease in the sealer penetration of the middle section was observed for the chlorhexidine and saline groups. Compared to other irrigant solutions, NaOCl promotes more uniform sealer penetration, which can correlate with better sealing and, consequently, higher endodontic treatment success.  相似文献   
69.
70.
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