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   46563篇
  免费   3322篇
  国内免费   2275篇
耳鼻咽喉   1545篇
儿科学   525篇
妇产科学   194篇
基础医学   6166篇
口腔科学   1070篇
临床医学   4581篇
内科学   4076篇
皮肤病学   250篇
神经病学   9262篇
特种医学   1452篇
外国民族医学   3篇
外科学   8305篇
综合类   6335篇
预防医学   942篇
眼科学   2645篇
药学   2584篇
  22篇
中国医学   1272篇
肿瘤学   931篇
  2024年   81篇
  2023年   707篇
  2022年   1078篇
  2021年   1653篇
  2020年   1674篇
  2019年   1479篇
  2018年   1441篇
  2017年   1647篇
  2016年   1634篇
  2015年   1577篇
  2014年   2770篇
  2013年   2792篇
  2012年   2294篇
  2011年   2543篇
  2010年   2172篇
  2009年   2097篇
  2008年   2272篇
  2007年   2289篇
  2006年   2038篇
  2005年   1763篇
  2004年   1669篇
  2003年   1450篇
  2002年   1265篇
  2001年   1132篇
  2000年   942篇
  1999年   888篇
  1998年   846篇
  1997年   793篇
  1996年   661篇
  1995年   593篇
  1994年   515篇
  1993年   486篇
  1992年   527篇
  1991年   430篇
  1990年   425篇
  1989年   354篇
  1988年   309篇
  1987年   310篇
  1986年   304篇
  1985年   391篇
  1984年   344篇
  1983年   225篇
  1982年   264篇
  1981年   227篇
  1980年   205篇
  1979年   140篇
  1978年   97篇
  1977年   96篇
  1976年   72篇
  1975年   49篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.

Background and objective

Erector spinae plane block is a valid technique to provide simultaneously analgesia for combined thoracic and abdominal surgery.

Case report

A patient underwent open esophagectomy followed by reconstructive esophagogastroplasty but refused thoracic epidural analgesia; a multi‐modal analgesia with a multiple erector spinae plane block was then planned. Three erector spinae plane catheters (T5 and T10 on the right side and T9 on the left side) for continuous analgesia were placed before surgery. During the first 48 h pain was never reported in the thoracic area but the patient reported multiple times to feel a pain well localized in epigastrium, but never localized in any other abdominal quadrant.

Discussion

Erector spinae plane block is a valid technique to provide analgesia simultaneously for combined thoracic and abdominal surgery and could be a valid alternative strategy if the use of epidural analgesia is contraindicated.  相似文献   
32.
33.
34.
35.

Background

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the “gold standard” of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

Methods

Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM).

Results

Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3?wt% silicone oil and 0.1?wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3?wt% silicone oil with cotton fiber and 66.6?wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1?mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites.

Conclusions

The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.  相似文献   
36.

Background

The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine.

Methods

Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome.

Results

All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85–7.62) h in the control group, 7.37 (5.78–7.93) h in the perineural group and 7.37 (6.10–7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups.

Conclusion

Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve.

Clinical trial registration

DRKS, 00014604; EudraCT, 2018-001221-98.  相似文献   
37.
38.
39.
Effective management and control of peri- and postoperative pain in hip surgery is essential in order to minimize the use of opioids and their adverse effects. Effective regional analgesia for hip pain is made particularly challenging by the complex innervation of the hip joint. Standard regional techniques can be associated with complications, including incomplete anesthesia, hypotension, or lower limb weakness. We present the case of a 5-year-old girl with a history of infantile cerebral palsy who underwent bilateral varus derotation osteotomy and adductor tenotomy due to paralytic dislocation. She received bilateral PENG block and femoral cutaneous nerve block - a simple technique that covers all the nerves involved in the sensory innervation of the joint capsule without the need for multiple injections.  相似文献   
40.
We describe a case of undiagnosed heart block which was detected during the postpartum surgical repair of a vaginal tear, and the subsequent investigations that confirmed diagnosis of atrio-ventricular heart block.  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