全文获取类型
收费全文 | 7703篇 |
免费 | 494篇 |
国内免费 | 366篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 323篇 |
妇产科学 | 400篇 |
基础医学 | 968篇 |
口腔科学 | 46篇 |
临床医学 | 1217篇 |
内科学 | 1105篇 |
皮肤病学 | 29篇 |
神经病学 | 312篇 |
特种医学 | 726篇 |
外国民族医学 | 1篇 |
外科学 | 686篇 |
综合类 | 1325篇 |
预防医学 | 246篇 |
眼科学 | 91篇 |
药学 | 736篇 |
1篇 | |
中国医学 | 231篇 |
肿瘤学 | 112篇 |
出版年
2024年 | 12篇 |
2023年 | 76篇 |
2022年 | 116篇 |
2021年 | 199篇 |
2020年 | 207篇 |
2019年 | 155篇 |
2018年 | 212篇 |
2017年 | 231篇 |
2016年 | 218篇 |
2015年 | 227篇 |
2014年 | 495篇 |
2013年 | 539篇 |
2012年 | 417篇 |
2011年 | 518篇 |
2010年 | 452篇 |
2009年 | 418篇 |
2008年 | 409篇 |
2007年 | 423篇 |
2006年 | 368篇 |
2005年 | 338篇 |
2004年 | 272篇 |
2003年 | 250篇 |
2002年 | 193篇 |
2001年 | 179篇 |
2000年 | 175篇 |
1999年 | 122篇 |
1998年 | 141篇 |
1997年 | 122篇 |
1996年 | 110篇 |
1995年 | 107篇 |
1994年 | 95篇 |
1993年 | 78篇 |
1992年 | 79篇 |
1991年 | 65篇 |
1990年 | 61篇 |
1989年 | 40篇 |
1988年 | 45篇 |
1987年 | 32篇 |
1986年 | 38篇 |
1985年 | 53篇 |
1984年 | 53篇 |
1983年 | 34篇 |
1982年 | 35篇 |
1981年 | 29篇 |
1980年 | 23篇 |
1979年 | 25篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 11篇 |
1973年 | 8篇 |
排序方式: 共有8563条查询结果,搜索用时 218 毫秒
11.
MICHAL J. KANTOCH ROXANE McKAY MICHAEL J. TYRRELL 《Pacing and clinical electrophysiology : PACE》1993,16(9):1887-1891
An 11-year-old girl who underwent Mustard's operation for complete transposition of the great arteries in infancy, developed Mobitz type II second-degree AV block 81/2 years later. A transvenous, active fixation left ventricular lead was inserted and connected to a rate responsive pacemaker. Two years later the lead dislodged due to the child's growth. A new active fixation electrode was positioned in the left ventricle below the pulmonary valve, leaving an electrode loop in the ventricle. Such an approach may prevent lead dislodgement due to growth after intraatrial repair for transposition of the great arteries, but regular radiological or echocardiographic follow-up of lead position is recommended in these patients. 相似文献
12.
Shang-Jin Shi Hiromi Rakugi Koichi Higashimori Jitsuo Higaki Hiroshi Mikami Toshio Ogihara 《Clinical and experimental pharmacology & physiology》1994,21(10):767-773
1. We previously reported that angiotensin II release from the mesenteric arteries of Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) increased in a time-dependent manner as a result of the isolation of the arteries and perfusion. This phenomenon appeared to be due to the withdrawal of circulating angiotensin II (AII). 2. The purpose of the present study was to test the hypothesis that vascular AII generation may be negatively regulated by circulating AII in WKY and SHR, and to clarify the role of this vascular angiotensin II in the sustained hypertension of SHR following nephrectomy. 3. The mesenteric arteries from kidney-intact and nephrectomized WKY and SHR were perfused and the amount of AII released into the perfusate was measured. The effects of the angiotensin converting enzyme inhibitor, captopril, and the effects of supplementation of renal renin and circulating angiotensins to nephrectomized rats, by blood exchange between kidney-intact and nephrectomized rats, on AII release were examined to clarify the pathway of vascular AII generation after nephrectomy. 4. Nephrectomy caused augmentation of vascular AII release both in WKY and SHR in spite of the abolishment of circulating renin. Captopril reduced this enhanced release of AII, but blood exchange did not affect it. There was no significant difference in these responses between WKY and SHR. 5. These results suggest that WKY and SHR have in common a potent pathway for production of vascular AII in response to the withdrawal of circulating AII, although this pathway is not responsible for the sustained hypertension of SHR after nephrectomy. The precise pathophysiological role of this pathway remains to be elucidated. 相似文献
13.
目的 探讨应用彩色多普勒超声显像方法对正常人足部动脉的解剖结构进行无损伤检测的可行性。方法 应用彩色多普勒检测对正常 32人 6 4足的足背、跖背、跖底动脉行径、来源与口径进行探测。结果 6 4足中 1 6只检测到足背动脉弓 ,出现率为 2 5 % ,36足检测到第二跖背动脉 ,出现率为 5 6 2 % ,37足检测到第二跖底动脉 ,出现率为 5 7 8% ;1例足背动脉缺如 ,占 1 6 % ,其第一跖背动脉来源于腓动脉。 5 9足检测到第一跖背动脉 ,出现率为 92 2 % ,其中 ,顾玉东Ⅰ型 ,占 2 8 1 % ,Ⅱ型 ,占 4 6 9% (30例 ) ,6足为ⅢS 型 ,占 9 4 % ,正常人足部动脉彩超结果表明 ,5足为Ⅵ型 ,占 7 8%。结论 应用彩色多普勒超声显像的方法可以对足部动脉的解剖结构进行无损伤的检测 ;以足背动脉为共同血管蒂 ,第一、二跖背 (底 )为动脉蒂共干同时移植拇趾皮甲瓣和第二足趾 (或二、三足趾 ) ,扩大再造手的虎口 ,改进现有单足供趾再造手技术的方法是可行的 相似文献
14.
Early assessment of renal resistance index after kidney transplant can help predict long-term renal function. 总被引:6,自引:0,他引:6
Angelo Saracino Giovanni Santarsia Angela Latorraca Vito Gaudiano 《Nephrology, dialysis, transplantation》2006,21(10):2916-2920
BACKGROUND: Color Doppler ultrasonography of intrarenal arterial resistance index (RI), performed early after kidney transplant, has proven to reliably predict short-term allograft function. The aim of this study was to assess whether it could also predict long-term renal function. METHODS: We retrospectively analysed 76 kidney transplant patients who underwent RI assessment within 1 month after the transplant, subdivided into two groups according to RI values, lower (group A) or higher (group B) than its median value (0.635). RESULTS: Compared with group A subjects, the patients of group B were older at the time of transplant (42 +/- 9 vs 35 +/- 8 years; P = 0.001), the donor age was also older (41 +/- 16 vs 33 +/- 13 years; P = 0.02) and had a slightly higher proteinuria (0.54 +/- 0.5 vs 0.32 +/- 0.2 g/24 h; P = 0.02). Serum creatinine, ciclosporin or tacrolimus trough level, arterial blood pressure, number of human leukocyte antigen (HLA) mismatches, anti-hypertensive medications and incidence of delayed graft function were not significantly different between the two groups. By univariate analysis, RI turned out to directly correlate with the recipient age, donor age and daily proteinuria (P = 0.007, P = 0.0007 and P = 0.02, respectively). Multivariate analysis showed that only donor and recipient age maintained their independent predictive value on RI. Kaplan-Meier analysis, considering a serum creatinine increase >50% as the endpoint of the study, showed a statistically significant different graft survival in the two groups (log-rank test = 5.489; P = 0.01). The univariate relative risk of deterioration of graft function among patients with higher RI was 3.77. Proteinuria and recipient age increased the risk as well. CONCLUSIONS: Our data seem to suggest that early determination of RI can help predict long-term graft function in kidney transplant recipients. 相似文献
15.
16.
大脑中动脉动脉瘤的血管内治疗 总被引:3,自引:3,他引:0
目的探讨血管内治疗大脑中动脉动脉瘤的可行性、安全性和有效性。方法回顾性分析采用血管内治疗的24例大脑中动脉动脉瘤患者的临床资料,包括患者年龄、临床分级、动脉瘤出血量、部位、形态、瘤颈宽度、血管痉挛程度及术中应用技术等。结果100%栓塞17例,95%栓塞4例,90%栓塞3例。1例患者术中血管痉挛加重致不完全失语。随访无动脉瘤再破裂出血病例,1例患者出现迟发性血管痉挛。结论血管内治疗大脑中动脉动脉瘤是一种安全、有效的方法。 相似文献
17.
Takanobu Anai M.D. Isao Miyakawa M.D. Ph.D. Hiromi Ohki M.D. Teruyuki Ogawa M.D. Ph.D. 《Pediatrics international》1992,34(3):324-327
There have been only 2 previous reports of nonimmunologic hydrops fetalis (NIHF) caused by fetal Kasabach-Merritt syndrome, both of which were pathological studies. This is the first clinical case report of NIHF due to fetal Kasabach-Merritt syndrome that was prenatally diagnosed by sonography, computerized tomography, and percutaneous umbilical blood sampling. 相似文献
18.
Shahriar Yazdanfar Gary S. Ledley Anthony Alfieri Clifford Strauss Morris N. Kotler 《Catheterization and cardiovascular interventions》1993,28(1):72-75
Percutaneous transluminal coronary angioplasty (PTCA) of heavily calcified rigid coronary arteries has decreased success and increased complication rates. Three cases are presented describing a new technique for the dilatation of severely calcified coronary arteries that were not dilatable by conventional angioplasty methods. This technique involves the use of a balloon dilatation catheter system parallel to a guide wire. © 1993 Wiley-Liss, Inc. 相似文献
19.
本文通过分析50例脑动静脉畸形(AVM)的全脑数字减影血管造影(DSA)资料及手术探查结果,探讨AVM的深、浅及供血、引流血管数量与出血发生率的关系。经统计比较发现:深部较浅部AVM出血率高;供应动脉条数多于导出静脉条数者及仅有单条导出静脉出血率最高,并与其他组有显著性差异(P<0.05、P<0.01)。因此,我们认为:在临床工作中对这些AVM患者应给予足够的重视。 相似文献
20.
应用脐静脉灌注冲洗人胎儿肝脏,胰蛋白酶消化后经光镜及扫描电镜观察,证实可获得纯度为90%以上的肝实质细胞,培养上清液可测出胎甲蛋白活性,证明胎肝细胞具有生物学活性,为应用人肝细胞培养进行生理生化及药理方面的实验研究,提供一种新的获取人肝细胞的方法. 相似文献