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   1278652篇
  免费   98229篇
  国内免费   1989篇
耳鼻咽喉   18435篇
儿科学   44354篇
妇产科学   35009篇
基础医学   182194篇
口腔科学   33586篇
临床医学   111256篇
内科学   258307篇
皮肤病学   28020篇
神经病学   100442篇
特种医学   51204篇
外国民族医学   660篇
外科学   196457篇
综合类   27058篇
现状与发展   1篇
一般理论   377篇
预防医学   95719篇
眼科学   27919篇
药学   94774篇
  2篇
中国医学   2423篇
肿瘤学   70673篇
  2018年   13135篇
  2017年   9964篇
  2016年   10900篇
  2015年   12369篇
  2014年   17167篇
  2013年   26215篇
  2012年   36024篇
  2011年   38063篇
  2010年   22804篇
  2009年   21811篇
  2008年   36650篇
  2007年   39256篇
  2006年   39512篇
  2005年   38462篇
  2004年   37610篇
  2003年   36460篇
  2002年   35812篇
  2001年   63992篇
  2000年   66507篇
  1999年   56421篇
  1998年   15131篇
  1997年   13757篇
  1996年   14197篇
  1995年   13454篇
  1994年   12767篇
  1993年   11792篇
  1992年   44562篇
  1991年   43470篇
  1990年   42221篇
  1989年   40118篇
  1988年   36901篇
  1987年   36239篇
  1986年   33623篇
  1985年   32281篇
  1984年   24143篇
  1983年   20272篇
  1982年   11724篇
  1981年   10691篇
  1980年   9515篇
  1979年   21345篇
  1978年   14827篇
  1977年   12539篇
  1976年   11694篇
  1975年   12626篇
  1974年   14665篇
  1973年   14117篇
  1972年   12949篇
  1971年   11730篇
  1970年   11051篇
  1969年   10024篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.

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   
5.
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   
6.
7.
8.

Background and aims

Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.

Methods and results

In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.

Conclusion

SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE.  相似文献   
9.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.  相似文献   
10.
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