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   1511859篇
  免费   111177篇
  国内免费   2359篇
耳鼻咽喉   21948篇
儿科学   52340篇
妇产科学   43329篇
基础医学   217510篇
口腔科学   39845篇
临床医学   130678篇
内科学   300724篇
皮肤病学   32982篇
神经病学   116840篇
特种医学   60173篇
外国民族医学   693篇
外科学   232967篇
综合类   33181篇
现状与发展   2篇
一般理论   515篇
预防医学   111893篇
眼科学   33854篇
药学   111451篇
  2篇
中国医学   3061篇
肿瘤学   81407篇
  2018年   15961篇
  2017年   12027篇
  2016年   13306篇
  2015年   15136篇
  2014年   20760篇
  2013年   31970篇
  2012年   43127篇
  2011年   45539篇
  2010年   27705篇
  2009年   26207篇
  2008年   43505篇
  2007年   46747篇
  2006年   46886篇
  2005年   45533篇
  2004年   44419篇
  2003年   42933篇
  2002年   41871篇
  2001年   73728篇
  2000年   76471篇
  1999年   64847篇
  1998年   17458篇
  1997年   15909篇
  1996年   16176篇
  1995年   15393篇
  1994年   14510篇
  1993年   13474篇
  1992年   50745篇
  1991年   49862篇
  1990年   48426篇
  1989年   46255篇
  1988年   42478篇
  1987年   41614篇
  1986年   38829篇
  1985年   37313篇
  1984年   27846篇
  1983年   23490篇
  1982年   13659篇
  1981年   12330篇
  1979年   24893篇
  1978年   17408篇
  1977年   14722篇
  1976年   13711篇
  1975年   14941篇
  1974年   17436篇
  1973年   16893篇
  1972年   15547篇
  1971年   14184篇
  1970年   13433篇
  1969年   12223篇
  1968年   11241篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
7.
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.

Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.

Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.

Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality.  相似文献   
8.
9.
10.
Abstract

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos.  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