全文获取类型
收费全文 | 164384篇 |
免费 | 31783篇 |
国内免费 | 2480篇 |
专业分类
耳鼻咽喉 | 5247篇 |
儿科学 | 5729篇 |
妇产科学 | 2729篇 |
基础医学 | 5425篇 |
口腔科学 | 1748篇 |
临床医学 | 27809篇 |
内科学 | 50526篇 |
皮肤病学 | 7606篇 |
神经病学 | 16500篇 |
特种医学 | 6635篇 |
外科学 | 41976篇 |
综合类 | 263篇 |
现状与发展 | 72篇 |
一般理论 | 4篇 |
预防医学 | 7691篇 |
眼科学 | 3442篇 |
药学 | 2061篇 |
中国医学 | 36篇 |
肿瘤学 | 13148篇 |
出版年
2024年 | 693篇 |
2023年 | 4886篇 |
2022年 | 1445篇 |
2021年 | 3492篇 |
2020年 | 6278篇 |
2019年 | 2487篇 |
2018年 | 7741篇 |
2017年 | 7641篇 |
2016年 | 8739篇 |
2015年 | 8828篇 |
2014年 | 15990篇 |
2013年 | 16243篇 |
2012年 | 6538篇 |
2011年 | 6547篇 |
2010年 | 10948篇 |
2009年 | 14755篇 |
2008年 | 6699篇 |
2007年 | 4932篇 |
2006年 | 7375篇 |
2005年 | 4594篇 |
2004年 | 3816篇 |
2003年 | 2772篇 |
2002年 | 2757篇 |
2001年 | 3874篇 |
2000年 | 3081篇 |
1999年 | 3322篇 |
1998年 | 3778篇 |
1997年 | 3556篇 |
1996年 | 3448篇 |
1995年 | 3296篇 |
1994年 | 2003篇 |
1993年 | 1624篇 |
1992年 | 1430篇 |
1991年 | 1447篇 |
1990年 | 1091篇 |
1989年 | 1228篇 |
1988年 | 1038篇 |
1987年 | 868篇 |
1986年 | 918篇 |
1985年 | 735篇 |
1984年 | 573篇 |
1983年 | 543篇 |
1982年 | 530篇 |
1981年 | 415篇 |
1980年 | 373篇 |
1979年 | 314篇 |
1978年 | 331篇 |
1977年 | 404篇 |
1975年 | 281篇 |
1972年 | 304篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
251.
252.
253.
254.
255.
Hiroshi Morita MD Douglas P. Zipes MD Shiho T. Morita MD Jiashin Wu PhD 《Heart rhythm》2007,4(1):66-74
BACKGROUND: The Brugada syndrome is characterized by ST-segment elevation on the ECG, especially in the right precordial leads sensitive to the right ventricular outflow tract (RVOT). OBJECTIVES: The purpose of this study was to evaluate the hypothesis that right ventricular electrophysiologic heterogeneity caused arrhythmogenicity in the Brugada syndrome. METHODS: Action potentials (APs) were mapped on the epicardium of 14 RVOT preparations and on the transmural surfaces of 15 pairs of RVOT and right ventricular anteroinferior (RVAI) preparations isolated from canine hearts. Brugada ECG and arrhythmias were induced with pilsicainide (2.5-12.5 micromol/L), pinacidil (1.25-12.5 micromol/L), and terfenadine (2.0 micromol/L). RESULTS: Low doses of drugs elevated the J-ST segment and induced APs with both short and long action potential durations (APDs) in contiguous RVOT epicardial regions. In addition, APs in the RVOT had a larger phase 1 notch and longer APD than in RVAI. The longest APDs were in the epicardium in RVOT but in the endocardium in RVAI regions. High doses of drugs eliminated the phase 2 dome of the AP and abbreviated APDs in the epicardium but not in endocardium and reduced the epicardial heterogeneity of APs but increased the transmural gradient of APD in 14 (93%) of the RVOT preparations. In contrast, abbreviations of epicardial APDs occurred in only 4 (27%) of the RVAI preparations. Ventricular tachycardia occurred more frequently in the RVOT (47%) than in paired RVAI preparations (7%). Blocking the transient outward current reduced the heterogeneity of APs and eliminated arrhythmogenicity in all preparations. CONCLUSION: Compared with the RVAI region, the RVOT has greater electrophysiologic heterogeneity that contributes to arrhythmogenicity in this model of Brugada syndrome. 相似文献
256.
257.
258.
259.
Four-Year Follow-up on Endovascular Radiofrequency Obliteration of Great Saphenous Reflux 总被引:4,自引:0,他引:4
Merchant Robert F. MD Pichot Olivier MD † Myers Kenneth A. MD ‡ 《Dermatologic surgery》2005,31(2):129-134
BACKGROUND: Endovascular radiofrequency obliteration has been used since 1998 as an alternative to conventional vein stripping surgery for elimination of saphenous vein insufficiency. OBJECTIVE: To demonstrate the long-term efficacy of this treatment modality. METHODS: Data were prospectively collected in a multicenter ongoing registry. Only great saphenous vein above-knee treatments were included in this study. Eight hundred ninety patients (1,078 limbs) were treated prior to November 2003 at 32 centers. Clinical and duplex ultrasound follow-up was performed at 1 week, 6 months, and 1, 2, 3, and 4 years. RESULTS: Among 1,078 limbs treated, 858 were available for follow-up within 1 week, 446 at 6 months, 384 at 1 year, 210 at 2 years, 114 at 3 years, and 98 at 4 years. The vein occlusion rates were 91.0%, 88.8%, 86.2%, 84.2%, and 88.8%, respectively; the reflux-free rates were 91.0%, 89.3%, 86.2%, 86.0%, and 85.7%, respectively; and the varicose vein recurrence rates were 7.2%, 13.5%, 17.1%, 14.0%, and 21.4%, respectively, at each follow-up time point at 6 months, and 1, 2, 3, and 4 years. Patient symptom improvement persisted over 4 years. CONCLUSIONS: Endovascular temperature-controlled radiofrequency obliteration of saphenous vein reflux exhibits an enduring treatment efficacy clinically, anatomically, and hemodynamically up to 4 years following treatment. 相似文献
260.