全文获取类型
收费全文 | 13781篇 |
免费 | 878篇 |
国内免费 | 418篇 |
专业分类
耳鼻咽喉 | 442篇 |
儿科学 | 523篇 |
妇产科学 | 54篇 |
基础医学 | 536篇 |
口腔科学 | 14篇 |
临床医学 | 1624篇 |
内科学 | 4350篇 |
皮肤病学 | 17篇 |
神经病学 | 989篇 |
特种医学 | 1103篇 |
外科学 | 2736篇 |
综合类 | 1705篇 |
现状与发展 | 2篇 |
预防医学 | 204篇 |
眼科学 | 102篇 |
药学 | 393篇 |
6篇 | |
中国医学 | 141篇 |
肿瘤学 | 136篇 |
出版年
2024年 | 26篇 |
2023年 | 249篇 |
2022年 | 361篇 |
2021年 | 632篇 |
2020年 | 625篇 |
2019年 | 572篇 |
2018年 | 618篇 |
2017年 | 406篇 |
2016年 | 458篇 |
2015年 | 503篇 |
2014年 | 958篇 |
2013年 | 923篇 |
2012年 | 670篇 |
2011年 | 791篇 |
2010年 | 660篇 |
2009年 | 607篇 |
2008年 | 604篇 |
2007年 | 631篇 |
2006年 | 580篇 |
2005年 | 506篇 |
2004年 | 413篇 |
2003年 | 365篇 |
2002年 | 303篇 |
2001年 | 260篇 |
2000年 | 246篇 |
1999年 | 218篇 |
1998年 | 212篇 |
1997年 | 182篇 |
1996年 | 162篇 |
1995年 | 162篇 |
1994年 | 143篇 |
1993年 | 137篇 |
1992年 | 125篇 |
1991年 | 97篇 |
1990年 | 82篇 |
1989年 | 78篇 |
1988年 | 70篇 |
1987年 | 55篇 |
1986年 | 46篇 |
1985年 | 53篇 |
1984年 | 53篇 |
1983年 | 19篇 |
1982年 | 56篇 |
1981年 | 41篇 |
1980年 | 34篇 |
1979年 | 26篇 |
1978年 | 18篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
11.
12.
13.
Nirmanmoh Bhatia Buddhadeb Dawn Tariq S. Siddiqui Marcus F. Stoddard 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(1):16-24
Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm2) was underestimated by the standard method (1.05 ± 0.47 cm2; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index. 相似文献
14.
Viviana Maestrini Lucia I. Birtolo Sara Cimino Paolo Severino Massimo Mancone Marco Francone Sanjay M. Banypersad Flavia Ventriglia Luigi Tritapepe Fabio Miraldi Francesco Fedele 《Echocardiography (Mount Kisco, N.Y.)》2019,36(5):992-995
A 20‐year‐old Congolese woman presented with presyncope, dyspnea, and anasarca. Past medical history was unremarkable. Echocardiography revealed a rare combination of giant right atrium (RA), a dilated and hypertrophied right ventricle, subvalvular pulmonary stenosis (subPS), severe tricuspid regurgitation (TR), pericardial effusion and what appeared to be a spontaneously closed ventricular septal defect (VSD). Cardiac Magnetic Resonance and Cardiac Computed Tomography confirmed the findings excluding the presence of intra‐cardiac and extra‐cardiac shunt and other associated congenital anomalies. The patient underwent subPS resection, right atrioplasty, and tricuspid annuloplasty. Multimodality approach facilitated the detection of the abnormalities and provided clarity when determining the optimal surgical strategy. 相似文献
15.
16.
17.
Masayuki Tori Masaaki Nakahara Hiroki Akamatsu Shigeyuki Ueshima Masashi Shimizu Kazuyasu Nakao 《Journal of hepato-biliary-pancreatic sciences》2006,13(5):472-476
Even for patients with multiple pancreaticoduodenal aneurysms, successful treatment with noninvasive operative procedures can be employed, if intraoperative devices are considered. A 73‐year‐old man, without any symptoms, was admitted to our hospital and had computed tomography (CT) scanning to examine his liver for hepatitis C virus (HCV). Selective superior mesenteric artery (SMA) angiography confirmed multiple aneurysms in the anterior inferior pancreaticoduodenal artery (AIPDA), one aneurysm in the posterior inferior mesenteric artery (PIPDA), and another in the occluded celiac trunk, all with severe calcification. All of the aneurysms were thought to communicate with each other. With the celiac artery occlusion, the right hepatic artery (RHA) was revealed to be supplied by collateral arteries from the aneurysms in the AIPDA, and the left hepatic artery was shown to be supplied by collaterals from the left gastric artery. Intraoperative Doppler echography, at the time of the clamping of both IPDAs, demonstrated a marked decrease of blood velocity in all aneurysms (before clamping, >50 cm/s; after, <10 cm/s), although loss of pulsation and a marked decrease of flow in the RHA were inevitable. Therefore, each of these two IPDAs were ligated on the proximal side to the aneurysm, thus preserving the blood flow of the pancreas head fed by the PIPDA; bypass grafting from the AIPDA to the RHA, using the great saphenous vein, was done at the same time. After the creation of an anastomosis, the hepatic venous oxygen saturation (ShvO2) increased from 38% (at the time of ligation of the IPDAs) to 57% under ventilation. The patient's postoperative clinical course was uneventful. We describe and discuss our successful noninvasive operative management of multiple pancreaticoduodenal aneurysms, done while monitoring the blood flow and ShvO2, with some consideration of the literature. 相似文献
18.
19.
目的:探讨椎管扩大成形术治疗腰椎管狭窄的效果。方法:椎板减压后复位,用棘突或髂骨植于一侧开槽处扩大椎管,并进行椎板及关节突关节植骨,对54例随访病人的手术前后临床表现及X线和CT进行比较。结果:随访6—39个月,临床优良率为81.1%。随访X线片显示椎板明显后移,CT测量与术前对比显示椎管内径扩大明显。结论:椎管扩大成形术操作简单,效果满意,术后并发症少,是治疗腰椎管狭窄的又一选择。 相似文献
20.
甲基强的松龙在胸椎管狭窄症围手术期的应用 总被引:3,自引:1,他引:2
目的探讨甲基强的松龙(MP)在胸椎管狭窄症围手术期应用的价值.方法对82例胸椎管狭窄症采用单纯后路胸椎板切除术患者进行回顾性研究.所有患者手术减压前30min给予MP 1000mg冲击.76例减压术后第1日起每日200mg递减,术后第5d停药.术后出现脊髓缺血再灌注(IR)损伤6例,其中3例MP用法同上;另3例术后出现脊髓IR损伤时即刻按NASCIS-Ⅱ方案治疗.结果本组76例术后呈现不同程度的恢复.另6例术后出现脊髓IR损伤,其中术后MP每日200mg递减治疗的3例患者神经功能恢复较慢,1例于术后6个月恢复至正常,2例术后1年随访时肌力恢复满意但肢体仍有麻痛感;采用NASCIS-Ⅱ方案治疗的3例患者中,2例于治疗后48h神经功能基本恢复正常,1例于术后1个月双下肢功能完全恢复正常.发生应激性溃疡1例.结论胸椎管狭窄症手术减压患者围手术期应用MP,具有预防和治疗脊髓继发性损伤的作用. 相似文献