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   2338321篇
  免费   184334篇
  国内免费   7505篇
耳鼻咽喉   31987篇
儿科学   78442篇
妇产科学   64278篇
基础医学   326146篇
口腔科学   63886篇
临床医学   209023篇
内科学   471832篇
皮肤病学   53365篇
神经病学   188594篇
特种医学   94707篇
外国民族医学   883篇
外科学   362437篇
综合类   53112篇
现状与发展   3篇
一般理论   747篇
预防医学   183472篇
眼科学   51062篇
药学   168819篇
  7篇
中国医学   4190篇
肿瘤学   123168篇
  2018年   23678篇
  2017年   18249篇
  2016年   21200篇
  2015年   23814篇
  2014年   33205篇
  2013年   50328篇
  2012年   64933篇
  2011年   69469篇
  2010年   42574篇
  2009年   41080篇
  2008年   65604篇
  2007年   70259篇
  2006年   71335篇
  2005年   69133篇
  2004年   66722篇
  2003年   64962篇
  2002年   62697篇
  2001年   112431篇
  2000年   116347篇
  1999年   97948篇
  1998年   28443篇
  1997年   25590篇
  1996年   26521篇
  1995年   26122篇
  1994年   24524篇
  1993年   22885篇
  1992年   79851篇
  1991年   78047篇
  1990年   75470篇
  1989年   72105篇
  1988年   66566篇
  1987年   65332篇
  1986年   61351篇
  1985年   59029篇
  1984年   44860篇
  1983年   37791篇
  1982年   22914篇
  1981年   20698篇
  1980年   19102篇
  1979年   40397篇
  1978年   28821篇
  1977年   24477篇
  1976年   22549篇
  1975年   23938篇
  1974年   28138篇
  1973年   27009篇
  1972年   24893篇
  1971年   22896篇
  1970年   21230篇
  1969年   19574篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
4.
5.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.  相似文献   
6.
7.
8.

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   
9.
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   
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