全文获取类型
收费全文 | 175610篇 |
免费 | 980篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 1143篇 |
儿科学 | 6693篇 |
妇产科学 | 3055篇 |
基础医学 | 16464篇 |
口腔科学 | 1573篇 |
临床医学 | 12332篇 |
内科学 | 30856篇 |
皮肤病学 | 675篇 |
神经病学 | 16425篇 |
特种医学 | 8908篇 |
外科学 | 28986篇 |
综合类 | 2325篇 |
预防医学 | 18029篇 |
眼科学 | 2760篇 |
药学 | 9420篇 |
中国医学 | 625篇 |
肿瘤学 | 16330篇 |
出版年
2021年 | 57篇 |
2020年 | 52篇 |
2019年 | 55篇 |
2018年 | 21961篇 |
2017年 | 17398篇 |
2016年 | 19541篇 |
2015年 | 947篇 |
2014年 | 831篇 |
2013年 | 796篇 |
2012年 | 6970篇 |
2011年 | 21001篇 |
2010年 | 18839篇 |
2009年 | 11522篇 |
2008年 | 19503篇 |
2007年 | 21728篇 |
2006年 | 573篇 |
2005年 | 2168篇 |
2004年 | 3351篇 |
2003年 | 4306篇 |
2002年 | 2434篇 |
2001年 | 271篇 |
2000年 | 411篇 |
1999年 | 160篇 |
1998年 | 194篇 |
1997年 | 197篇 |
1996年 | 83篇 |
1995年 | 96篇 |
1994年 | 92篇 |
1993年 | 57篇 |
1992年 | 36篇 |
1991年 | 82篇 |
1990年 | 122篇 |
1989年 | 73篇 |
1988年 | 52篇 |
1987年 | 39篇 |
1986年 | 21篇 |
1985年 | 28篇 |
1983年 | 20篇 |
1982年 | 24篇 |
1980年 | 39篇 |
1974年 | 19篇 |
1970年 | 19篇 |
1969年 | 20篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
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
13.
14.
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
15.
16.
Burcin Ustbas Gul Deniz Kilic Yanilmaz Dilan Arslan Mehmet Bayramicli Ozge Akbulut 《Journal of plastic, reconstructive & aesthetic surgery》2019,72(3):477-483
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17.
18.
19.
20.