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   2351篇
  免费   150篇
  国内免费   11篇
耳鼻咽喉   11篇
儿科学   179篇
妇产科学   57篇
基础医学   349篇
口腔科学   107篇
临床医学   213篇
内科学   393篇
皮肤病学   122篇
神经病学   235篇
特种医学   63篇
外科学   230篇
综合类   13篇
一般理论   2篇
预防医学   191篇
眼科学   19篇
药学   183篇
中国医学   4篇
肿瘤学   141篇
  2023年   12篇
  2022年   13篇
  2021年   39篇
  2020年   38篇
  2019年   54篇
  2018年   67篇
  2017年   50篇
  2016年   67篇
  2015年   55篇
  2014年   99篇
  2013年   132篇
  2012年   167篇
  2011年   175篇
  2010年   96篇
  2009年   85篇
  2008年   165篇
  2007年   185篇
  2006年   165篇
  2005年   138篇
  2004年   152篇
  2003年   120篇
  2002年   136篇
  2001年   20篇
  2000年   15篇
  1999年   11篇
  1998年   16篇
  1997年   23篇
  1996年   14篇
  1995年   32篇
  1994年   19篇
  1993年   18篇
  1992年   18篇
  1991年   13篇
  1990年   8篇
  1989年   8篇
  1988年   4篇
  1987年   3篇
  1986年   8篇
  1984年   14篇
  1983年   10篇
  1982年   9篇
  1981年   4篇
  1980年   5篇
  1979年   3篇
  1978年   2篇
  1977年   6篇
  1975年   2篇
  1974年   4篇
  1973年   3篇
  1965年   2篇
排序方式: 共有2512条查询结果,搜索用时 15 毫秒
1.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities.  相似文献   
2.
3.
4.
5.
Three-dimensional cone beam computerized tomography in dentistry   总被引:1,自引:0,他引:1  
Palomo JM  Kau CH  Palomo LB  Hans MG 《Dentistry today》2006,25(11):130, 132-130, 135
  相似文献   
6.
7.
Purpose This in vitro study investigated the effect of lateral cyclic loading with different load positions and periods on abutment rotational displacement (RD) of external hexagon implant system. Materials and Methods Four groups of five implant assemblies each were used. Each assembly consisted of Brånemark System® Mk IV implant (Nobel Biocare AB, Göteborg, Sweden), CeraOne® abutment (Nobel Biocare AB), and a cement‐retained casting. A cyclic load of 50 N was applied centrally and perpendicular to the long axis of the implant for groups A and B for 0.25 and 0.50 × 106 cycles, respectively, while for groups C and D, the same load was applied at 4‐mm distance eccentrically for 0.25 and 0.50 × 106 cycles, respectively. The displacement was evaluated by hand drawing a longitudinal line across the implant‐abutment interface. Before and after loading, the lateral distance between two reference points on the abutment and implant was measured under high resolution (×200) and the difference formed the RD value. The data were analyzed with one‐way analysis of variance and compared with Tukey test (α=0.05). Results Group D had the highest mean of RD value (55.00 ± 1.871 μm), while group A had the lowest (2.800 ± 0.837 μm). Groups A and B had a high statistically significant difference in RD values, as compared to groups C or D (p < .001). Moreover, group C had statistically significant difference from group D (p=.011). Conversely, no statistical significance was obtained when group A was compared with group B. Conclusion Within the limits of this in vitro study, the RD of the external hexagon joint components occurred significantly under eccentric lateral loading when compared to centric loading. The displacement increased significantly with longer period of eccentric lateral loading.  相似文献   
8.
The aim of the present study was to discover any possible correlation between specific antibodies against Actinobacillus actinomycetemcomitans (A.a.) in serum and saliva. The test group consisted of 38 patients aged 31–68 yr (mean 49) with advanced periodontitis. Twenty-nine subjects aged 23–67 yr, without periodontal destruction, formed a control group with a reference level of specific salivary antibodies against A.a. A subgingival plaque sample for culturing A.a. , a specimen of stimulated whole saliva, and a sample of venous blood were taken from each subject of the test group. Specific IgG and IgA antibodies against A.a. were determined from serum and stimulated whole saliva by means of the ELISA test. Fifteen of the patients (39%) had cultivable A.a. Six of the 15 A.a. culture-positive patients and one of the 29 reference subjects exhibited very high antibody titers against A.a. in saliva. Specific IgG and IgA antibodies in saliva correlated highly significantly with the corresponding antibody values in serum among the patients in the test group. It was concluded that among patients with severe adult periodontitis, the less invasive saliva sample has a diagnostic value equal to that of the serum sample concerning specific antibodies against A.a.  相似文献   
9.
This study investigates narratives of Finnish children with specific language impairment (SLI) from linguistic and pragmatic perspectives, in order to get a comprehensive overview of these children’s narrative abilities. Nineteen children with SLI (mean age 6;1 years) and 19 typically developing age-matched children participated in the study. Their picture-elicited narrations were analysed for linguistic productivity and complexity, grammatical and referential accuracy, event content, the use of mental state expressions and narrative comprehension. Children with SLI showed difficulties in every aspect of narration in comparison to their peers. Only one measure of productivity, the number of communication units, did not reach statistical significance. Not only was linguistic structure fragile but also pragmatic aspects of storytelling (referencing, event content, mental state expressions and inferencing) were demanding for children with SLI. Results suggest that pragmatic aspects of narration should be taken into account more often when assessing narrative abilities of children with SLI.  相似文献   
10.

Purpose

The purpose of this study is to evaluate quantitative changes in diffusion tensor imaging (DTI) tractography and fractional anisotropy (FA) of the pons along with clinical correlation, in patients who receive re-irradiation for progressive diffuse intrinsic pontine glioma (DIPG).

Methods

A retrospective case review of children with progressive DIPG who received re-irradiation at our institution from 2007 to 2011 after approval from the Institutional Review Board was performed. Tractography analysis and FA were analyzed pre and post-re-irradiation, and correlation with clinical features and MR imaging was performed.

Results

DTI analysis showed reduced values of FA on tumor progression. Increase in the FA values was noted after re-irradiation in these patients. This correlated with clinical improvement. These changes were concordant with the 3D tractography analysis which showed better visualization of the corticospinal tracts as they course through brainstem and posterior transverse pontine fibers following re-irradiation.

Conclusion

Serial changes in the FA values using DTI could provide clinically more correlative information in patients with progressive DIPG, who receive re-irradiation. Though the use and results of this modality has been reported in the newly diagnosed DIPG before, evaluation of DTI in children who receive re-irradiation for progressive DIPG has not been reported earlier. Though limited by the small sample size and treatment variability, this study for the first time shows the preliminary experience, potential, and likely efficacy of complementing DTI analysis to routine neuroimaging also in patients re-irradiated for progressive DIPG to better assess treatment response.  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