全文获取类型
收费全文 | 2389篇 |
免费 | 100篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 104篇 |
妇产科学 | 28篇 |
基础医学 | 444篇 |
口腔科学 | 82篇 |
临床医学 | 264篇 |
内科学 | 540篇 |
皮肤病学 | 116篇 |
神经病学 | 46篇 |
特种医学 | 270篇 |
外科学 | 226篇 |
综合类 | 70篇 |
一般理论 | 1篇 |
预防医学 | 88篇 |
眼科学 | 32篇 |
药学 | 156篇 |
中国医学 | 1篇 |
肿瘤学 | 46篇 |
出版年
2015年 | 24篇 |
2013年 | 74篇 |
2012年 | 22篇 |
2010年 | 43篇 |
2009年 | 31篇 |
2008年 | 22篇 |
2007年 | 42篇 |
2006年 | 44篇 |
2005年 | 23篇 |
2003年 | 23篇 |
2001年 | 29篇 |
2000年 | 23篇 |
1999年 | 35篇 |
1998年 | 88篇 |
1997年 | 100篇 |
1996年 | 107篇 |
1995年 | 71篇 |
1994年 | 76篇 |
1993年 | 77篇 |
1992年 | 44篇 |
1991年 | 41篇 |
1990年 | 45篇 |
1989年 | 68篇 |
1988年 | 59篇 |
1987年 | 50篇 |
1986年 | 54篇 |
1985年 | 38篇 |
1984年 | 58篇 |
1983年 | 29篇 |
1982年 | 34篇 |
1981年 | 38篇 |
1980年 | 50篇 |
1979年 | 23篇 |
1978年 | 30篇 |
1977年 | 35篇 |
1976年 | 39篇 |
1975年 | 37篇 |
1972年 | 24篇 |
1971年 | 21篇 |
1970年 | 23篇 |
1965年 | 50篇 |
1964年 | 50篇 |
1963年 | 48篇 |
1962年 | 43篇 |
1961年 | 40篇 |
1960年 | 67篇 |
1959年 | 48篇 |
1958年 | 46篇 |
1955年 | 24篇 |
1954年 | 41篇 |
排序方式: 共有2519条查询结果,搜索用时 15 毫秒
91.
NELSON RODRIGUES NETTO JR. SANDRO C. ESTEVES PAULO A. NEVES 《The Journal of urology》1998,159(6):2048-2053
Purpose
We determine how transurethral resection of the ejaculatory ducts performed for infertility affects seminal parameters and pregnancy outcomes in patients with partial ejaculatory duct obstruction due to a congenital or acquired etiological factor.Materials and Methods
Based on history and physical examination, hormonal profiles, semen analyses, transrectal ultrasonography and vasography findings partial ejaculatory duct obstruction was diagnosed in 14 men a mean of 30 years old who presented for infertility evaluation. Patients were grouped according to congenital or acquired cause of obstruction. Transurethral resection of the ejaculatory ducts was performed using the standard resectoscope loop technique. Clinical outcome was assessed by postoperative analyses of seminal parameters and pregnancy reports.Results
Transurethral resection of the ejaculatory ducts significantly improved semen quality (ejaculate volume and percentage of sperm motility) in all patients in the congenital group, while all but 1 (83%) had an improved sperm count. Pregnancy was achieved via sexual intercourse by 66% of the patients an average of 5.7 months postoperatively. Of the acquired etiological factor group 37.5% had improved semen quality after transurethral resection of ejaculatory duct and 12.5% achieved pregnancy via sexual intercourse. Postoperative complications occurred at a similar rate in each group (33%). However, complications in the congenital etiology group were minor, while 25% of the men in the acquired group had significant impairment of seminal parameters after transurethral resection of the ejaculatory ducts.Conclusions
Semen quality improvement and pregnancy outcome after transurethral resection of the ejaculatory ducts for partial ejaculatory duct obstruction differ significantly according to the main etiological cause of obstruction. An equivocal diagnosis of partial obstruction and technical problems during transurethral resection of the ejaculatory ducts may contribute to failure. However, in some cases the reason for failure remains unclear. 相似文献92.
评价无支架异种生物瓣膜主动脉瓣替换术后2年左室功能的变化。将80例同期施行主动脉瓣替换病人分为2组,50例(年龄69.3±9.3岁)应用TorontoSPVTM瓣;30例(年龄71.6±7.7岁)作为对照组接受支架人工瓣膜替换。术前、术后1、6、12及24个月间记录M型及Doppler超声心动图,采用计算机图像数字分析,定量测定左室功能的变化。随访期间,Toronto组主动脉瓣跨瓣压差为0.8±0.6kPa(6.0±4.5mmHg),明显低于对照组2.3±0.9kPa(17.3±6.8mmHg);术后1个月,左室心肌质量下降25%,左室+Vcf及-Vcf明显增加(2.0±0.8/1.4±0.3s-1,P<0.01;2.8±1.2/1.8±0.7s-1,P<0.01)。术后6个月,左室功能进一步改善,心室肥厚的消退更趋完全,该变化在其后的随访期间保持稳定。结论:与支架瓣膜相比,无支架异种生物瓣膜具有较大瓣口开放面积及低跨瓣压差,这促进了术后左室功能的恢复及病理性肥厚的逆转 相似文献
93.
94.
95.
96.
97.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
98.
AimsThe aim of the literature review was to identify new and emerging out of hospital emergency care roles and to describe their activity and impact.BackgroundDemographic changes, increased demands for health services, altered working practices, and health system economic pressures have led to the development of a disparate set of new health care roles.Data sourcesMEDLINE, EMBASE and CINAHL databases, and the two search engines Google and Google Scholar were searched for contemporary studies in the identified study area.Review methodsAll publications identified through the search were assessed for relevance. Those that discussed new roles were included (n = 34) and empirical studies (n = 14) analysed in detail.ResultsEmergency care and paramedic practitioner roles (ECP & PP) are having an impact on patient care, including an average 25% reduction in the conveyance rate to hospital, improved inter-professional working, immediacy of treatment and referral, and high patient satisfaction. Limited economic data suggests savings of between £31 (USD 55) and £37 (USD 65) per case when ECPs replace standard ambulance responders. Concerns have been expressed about patient safety, recruitment and training levels, regulatory and role implementation issues.ConclusionFurther work is required to fully understand the patient safety, clinical practice, professional role and financial implications of these new roles. 相似文献
99.
100.