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   241161篇
  免费   8027篇
  国内免费   4692篇
耳鼻咽喉   1733篇
儿科学   7378篇
妇产科学   3868篇
基础医学   23787篇
口腔科学   2729篇
临床医学   20380篇
内科学   40047篇
皮肤病学   1472篇
神经病学   19702篇
特种医学   11399篇
外国民族医学   22篇
外科学   35597篇
综合类   14737篇
现状与发展   10篇
一般理论   4篇
预防医学   23448篇
眼科学   4425篇
药学   16487篇
  44篇
中国医学   4993篇
肿瘤学   21618篇
  2024年   244篇
  2023年   968篇
  2022年   2505篇
  2021年   3194篇
  2020年   2422篇
  2019年   2235篇
  2018年   23954篇
  2017年   19352篇
  2016年   21411篇
  2015年   3914篇
  2014年   4285篇
  2013年   4211篇
  2012年   11500篇
  2011年   25839篇
  2010年   22076篇
  2009年   14099篇
  2008年   22611篇
  2007年   25149篇
  2006年   3902篇
  2005年   5124篇
  2004年   6512篇
  2003年   7970篇
  2002年   5728篇
  2001年   2961篇
  2000年   2243篇
  1999年   1552篇
  1998年   990篇
  1997年   944篇
  1996年   649篇
  1995年   600篇
  1994年   511篇
  1993年   323篇
  1992年   432篇
  1991年   437篇
  1990年   431篇
  1989年   348篇
  1988年   281篇
  1987年   238篇
  1986年   196篇
  1985年   196篇
  1984年   121篇
  1983年   111篇
  1982年   89篇
  1981年   72篇
  1980年   96篇
  1979年   67篇
  1978年   58篇
  1974年   62篇
  1938年   61篇
  1932年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Contraceptive use is an important strategy for the prevention of unwanted pregnancy and avoidance of induced abortion. Of all the contraception methods, emergency contraceptive (EC) offers the last chance to achieve this. However, few studies have documented the use of EC among young people in Ghana. This study explored knowledge and usage of EC as well as the factors associated with it among University of Cape Coast students. Data were obtained on the knowledge and usage of ECs among University of Cape Coast students in 2013. Logistic regression analysis was used to investigate the association between students’ socio-demographic characteristics and EC knowledge and use. More male students (72 %) than females (59 %) were sexually active. Fifty-seven percent of the respondents had ever heard of EC and 36 % had ever used EC. Although males were more likely to be sexually active, females were more likely to have knowledge of EC use compared to males. The study underscores the need to increase awareness regarding EC among University students in order to offer them the opportunity that EC provides if other forms of contraceptives are missed.  相似文献   
44.
45.
46.
Gastroesophageal reflux is the most common benign disorder of the esophagus and laparoscopic Nissen fundoplication has become the standard surgical treatment for its treatment. In our area, where the use of bougie calibration is debatable, postoperative dysphagia is encountered often after this surgery although it is usually not permanent. The aim of this study was to investigate the effect of using a soft silicone tube 39 F in diameter for esophageal calibration during laparoscopic Nissen fundoplication on the incidence of postoperative dysphagia. We divided cases scheduled to undergo laparoscopic Nissen fundoplication between January 2009 and November 2010 into two groups, each consisting 25 patients. Esophageal calibration with a 39 F silicone orogastric tube was used for the first group while there was no operative calibration in the second group. The surgical duration was recorded; the presence and severity of the postoperative dysphagia was calculated by using a dysphagia severity scoring system during the 1-year postoperative follow-up. The dysphagia severity scores were significantly lower in group 1 than group 2 on the postoperative second day and at the end of the first week and first month. We did not find a significant difference at the end of the 6-month and first year. There was also no significant difference regarding surgery duration. The use of a soft orogastric tube 39 F in diameter for esophagus calibration during laparoscopic Nissen fundoplication has significantly decreased the incidence of postoperative transient dysphagia without affecting the duration of surgery. Although dysphagia gradually resolves in the majority of patients, a safe and easy calibration method for its prevention is worth developing, and we believe that the use of our method in larger series could be beneficial.  相似文献   
47.
目的:统计分析中国县级及以上医疗机构青光眼亚专科建设、诊疗设备配备和服务提供情况,为进 一步推动我国青光眼防治工作提供理论依据。方法:调查研究。2015年对全国提供眼科服务的县级 及以上医疗机构通过网上填报的方式进行普查,采用描述性统计方法,对我国县级及以上医疗机构 青光眼亚专科建设、诊疗设备配备和服务提供情况进行系统整理和统计分析。结果:本次调查覆盖 全国6 341家县级及以上医疗机构,其中设立青光眼亚专科的医疗机构有672家(10.60%)。在青光眼 检查和治疗相关设备中,视力表配置率最高(99.30%),平均每家医疗机构配置3.28台;超声生物显 微镜配置率最低(11.50%),平均每家医疗机构配置0.13台。眼压测量、白内障手术和小梁切开术是 青光眼主要的诊疗服务类型。结论:我国县级及以上医疗机构青光眼亚专科建设亟待加强,诊疗设 备配备不全,诊疗服务能力需要全面提升。  相似文献   
48.
49.

Purpose

To evaluate the feasibility of a same-day yttrium-90 (90Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.

Materials and Methods

All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.

Results

All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned 90Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy–limiting toxicities. The mean total procedure time was 4.2 hours.

Conclusions

A same-day 90Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy.  相似文献   
50.
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