全文获取类型
收费全文 | 622篇 |
免费 | 21篇 |
国内免费 | 26篇 |
专业分类
儿科学 | 56篇 |
妇产科学 | 10篇 |
基础医学 | 53篇 |
口腔科学 | 27篇 |
临床医学 | 67篇 |
内科学 | 113篇 |
皮肤病学 | 12篇 |
神经病学 | 9篇 |
特种医学 | 68篇 |
外科学 | 75篇 |
综合类 | 36篇 |
预防医学 | 37篇 |
眼科学 | 5篇 |
药学 | 81篇 |
中国医学 | 1篇 |
肿瘤学 | 19篇 |
出版年
2022年 | 4篇 |
2018年 | 6篇 |
2015年 | 7篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 6篇 |
2007年 | 16篇 |
2006年 | 17篇 |
2005年 | 12篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 13篇 |
1998年 | 33篇 |
1997年 | 30篇 |
1996年 | 20篇 |
1995年 | 21篇 |
1994年 | 20篇 |
1993年 | 23篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 16篇 |
1989年 | 19篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 17篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1976年 | 5篇 |
1974年 | 3篇 |
1965年 | 3篇 |
1959年 | 10篇 |
1958年 | 21篇 |
1957年 | 30篇 |
1956年 | 23篇 |
1955年 | 19篇 |
1954年 | 21篇 |
1949年 | 16篇 |
1948年 | 19篇 |
排序方式: 共有669条查询结果,搜索用时 15 毫秒
1.
2.
报道新化合物A-失碳-17β-羟基-17α-乙炔基-Δ3(5),9(10)-雌甾二烯-2-酮2的合成。文中探讨了用炔钾粗品对A-失碳-Δ3(5),9(10)-雌甾二烯-2,17-二酮1和A-失碳-6β,19-环氧-Δ3-雄甾-2,17-二酮3的选择性炔化,分别得标题化合物2(44%)及A-失碳-17β-羟基-17α-乙炔基-6β,19-环氧-Δ3雄甾-2-酮4(65%),4经还原性破开环氧、去羟甲基和去醋酰氧基合成了标题化合物2。四步总收率为34%。 相似文献
3.
Two modified helical basket extractors are described that have increased the success rate of removing ureteral calculi using fluoroscopy from 63% to 92%. Initially a rather stiff and expandable basket with a 20-cm filiform tip is used with coaxial catheters and sheath (stage 1). If this procedure is unsuccessful, a basket with two long cable ends is passed from the nephrostomy out through the urethra (stage 2). When used with coaxial bladder catheters, this technique allows dilatation of the vesicoureteric junction and retrograde catheterization and injection of fluids or gas to dislodge the stone prior to extraction. In a series of 38 patients, stones were removed in all but three (a success rate of 92%). In five cases small stones (less than 5 mm) were not retrieved but subsequent studies were normal. Ureteral stones were found in the abdominal ureter in 28 cases, in the pelvic ureter in seven cases, and in multiple sites in three cases. Stones were larger than 1 cm in 27.7% of cases. Postextraction mucosal edema with reduced ureteral patency was common but usually cleared in 2-3 days. Occasional complications were related to the nephrostomy. 相似文献
4.
5.
6.
An audit of adverse events in children sedated with chloral hydrate or propofol during imaging studies 总被引:2,自引:1,他引:1
CRAIG MEROLA MD CYNTHIA ALBARRACIN RN PHILIP LEBOWITZ MD ROBERT S. BIENKOWSKI PhD SAMUEL M. BARST MD 《Paediatric anaesthesia》1995,5(6):375-378
We examined records of sedations provided by the paediatric anaesthesiology staff for 455 children (ages 1 mo-17 yr) undergoing MRI or CT scans at our institution over a twelve-month period with regard to the monitoring of adverse events: excessive sedation, agitation, vomiting, hypoxaemia, and major airway compromise. One hundred-and-thirty-one patients (29%) received chloral hydrate; 324 patients (71%) received propofol. All patients were monitored with continuous noninvasive pulse oximetry and received supplemental oxygen via nasal cannulae. Of the patients who received chloral hydrate, 64 (49%) were over one year of age; of the patients who received propofol, 318 (98%) were one year of age or older. In the chloral hydrate group, 23 patients (19%) were deemed excessively sedated and four patients (3%) were agitated; no patients in the propofol group experienced any of the adverse outcomes reviewed. Furthermore, no patients in either group had significant airway compromise and none was admitted to the hospital as a result of the sedation. 相似文献
7.
Retrorenal colon: implications for percutaneous diskectomy 总被引:1,自引:0,他引:1
It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary. 相似文献
8.
9.
10.