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   242404篇
  免费   11949篇
  国内免费   398篇
耳鼻咽喉   3192篇
儿科学   7611篇
妇产科学   4979篇
基础医学   34876篇
口腔科学   5632篇
临床医学   19230篇
内科学   53222篇
皮肤病学   6435篇
神经病学   21659篇
特种医学   7548篇
外国民族医学   106篇
外科学   30401篇
综合类   1012篇
一般理论   65篇
预防医学   21592篇
眼科学   4904篇
药学   17017篇
中国医学   717篇
肿瘤学   14553篇
  2023年   1285篇
  2022年   880篇
  2021年   3534篇
  2020年   2099篇
  2019年   3959篇
  2018年   7612篇
  2017年   5032篇
  2016年   5071篇
  2015年   5614篇
  2014年   5889篇
  2013年   9458篇
  2012年   16456篇
  2011年   16374篇
  2010年   8160篇
  2009年   6064篇
  2008年   14072篇
  2007年   15061篇
  2006年   13882篇
  2005年   13743篇
  2004年   12920篇
  2003年   11788篇
  2002年   11209篇
  2001年   6440篇
  2000年   6573篇
  1999年   5816篇
  1998年   961篇
  1997年   783篇
  1996年   761篇
  1992年   3341篇
  1991年   2996篇
  1990年   2877篇
  1989年   2624篇
  1988年   2509篇
  1987年   2326篇
  1986年   2231篇
  1985年   2025篇
  1984年   1499篇
  1983年   1285篇
  1982年   727篇
  1979年   1338篇
  1978年   920篇
  1977年   870篇
  1975年   857篇
  1974年   1051篇
  1973年   1073篇
  1972年   1000篇
  1971年   983篇
  1970年   925篇
  1969年   958篇
  1968年   855篇
排序方式: 共有10000条查询结果,搜索用时 362 毫秒
101.

Background

Available models for predicting lymph node invasion (LNI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP) might not be applicable to men diagnosed via magnetic resonance imaging (MRI)-targeted biopsies.

Objective

To assess the accuracy of available tools to predict LNI and to develop a novel model for men diagnosed via MRI-targeted biopsies.

Design, setting, and participants

A total of 497 patients diagnosed via MRI-targeted biopsies and treated with RP and extended pelvic lymph node dissection (ePLND) at five institutions were retrospectively identified.

Outcome measurements and statistical analyses

Three available models predicting LNI were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analyses. A nomogram predicting LNI was developed and internally validated.

Results and limitations

Overall, 62 patients (12.5%) had LNI. The median number of nodes removed was 15. The AUC for the Briganti 2012, Briganti 2017, and MSKCC nomograms was 82%, 82%, and 81%, respectively, and their calibration characteristics were suboptimal. A model including PSA, clinical stage and maximum diameter of the index lesion on multiparametric MRI (mpMRI), grade group on targeted biopsy, and the presence of clinically significant PCa on concomitant systematic biopsy had an AUC of 86% and represented the basis for a coefficient-based nomogram. This tool exhibited a higher AUC and higher net benefit compared to available models developed using standard biopsies. Using a cutoff of 7%, 244 ePLNDs (57%) would be spared and a lower number of LNIs would be missed compared to available nomograms (1.6% vs 4.6% vs 4.5% vs 4.2% for the new nomogram vs Briganti 2012 vs Briganti 2017 vs MSKCC).

Conclusions

Available models predicting LNI are characterized by suboptimal accuracy and clinical net benefit for patients diagnosed via MRI-targeted biopsies. A novel nomogram including mpMRI and MRI-targeted biopsy data should be used to identify candidates for ePLND in this setting.

Patient summary

We developed the first nomogram to predict lymph node invasion (LNI) in prostate cancer patients diagnosed via magnetic resonance imaging-targeted biopsy undergoing radical prostatectomy. Adoption of this model to identify candidates for extended pelvic lymph node dissection could avoid up to 60% of these procedures at the cost of missing only 1.6% patients with LNI.  相似文献   
102.
103.
104.
This study was aimed at determining the cause for the high incidence of tuberculosis (TB) reactivation occurring in males with a low body mass index (BMI). Current thinking about pulmonary TB describes infection in the lung apex resulting in cavitation after reactivation. A different hypothesis is put forward for TB infection, suggesting that this occurs in subclinical apical cavities caused by increased pleural stress due to a low BMI body habitus. A finite element analysis (FEA) model of a lung was constructed including indentations for the first rib guided by paramedian sagittal CT reconstructions, and simulations were conducted with varying antero‐posterior (AP) diameters to mimic chests with a different thoracic index (ratio of AP to the transverse chest diameters). A Pubmed search was conducted about gender and thoracic index, and the effects of BMI on TB. FEA modeling revealed a tenfold increase in stress levels at the lung apex in low BMI chests, and a four‐fold increase with a low thoracic index, r2 = 0.9748 P < 0.001. Low thoracic index was related to BMI, P = 0.001. The mean thoracic index was statistically significantly lower in males, P = 0.001, and increased with age in both genders. This article is the first to suggest a possible mechanism linking pulmonary TB reactivation to low BMI due to the flattened thoracic wall shape of young male adults. The low thoracic index in young males may promote TB reactivation due to tissue destruction in the lung apex from high pleural stress levels. Clin. Anat. 28:614–620, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
105.
106.
107.
108.

The COVID-19 crisis represents a global health concern, including mental health. Regarding the necessity to assess anxiety related to COVID-19, a scale was developed (Ahorsu et al., 2020). The goal of the present study was to validate the Fear of COVID-19 Scale (FCV-19S) in French (official language in 29 countries), and investigate its relationship with indicators of affective disturbances. The sample comprised 316 participants (271 females) recruited online during the French lockdown. They were from several regions of France. The FCV-19S underwent a forward-backward translation procedure. Its psychometric properties were evaluated with the confirmatory factor analysis (CFA). The French FCV-19S demonstrated a stable unidimensional structure with robust psychometric properties (strong internal consistency, good convergent and divergent validity, and good test-retest validity). With its robust psychometric properties in assessing the unidimensional construct of the fear of COVID-19, this scale will help to provide a better understanding of the relationship between emotions and psychological or psychiatric disorders during the pandemics in French-speaking countries.

  相似文献   
109.
110.
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