全文获取类型
收费全文 | 15610篇 |
免费 | 619篇 |
国内免费 | 217篇 |
专业分类
耳鼻咽喉 | 307篇 |
儿科学 | 253篇 |
妇产科学 | 128篇 |
基础医学 | 741篇 |
口腔科学 | 26篇 |
临床医学 | 3333篇 |
内科学 | 7164篇 |
皮肤病学 | 8篇 |
神经病学 | 619篇 |
特种医学 | 298篇 |
外科学 | 737篇 |
综合类 | 1648篇 |
一般理论 | 1篇 |
预防医学 | 280篇 |
眼科学 | 19篇 |
药学 | 741篇 |
4篇 | |
中国医学 | 100篇 |
肿瘤学 | 39篇 |
出版年
2024年 | 14篇 |
2023年 | 236篇 |
2022年 | 424篇 |
2021年 | 530篇 |
2020年 | 528篇 |
2019年 | 463篇 |
2018年 | 490篇 |
2017年 | 358篇 |
2016年 | 333篇 |
2015年 | 372篇 |
2014年 | 1046篇 |
2013年 | 889篇 |
2012年 | 631篇 |
2011年 | 729篇 |
2010年 | 643篇 |
2009年 | 764篇 |
2008年 | 780篇 |
2007年 | 829篇 |
2006年 | 813篇 |
2005年 | 709篇 |
2004年 | 538篇 |
2003年 | 475篇 |
2002年 | 357篇 |
2001年 | 367篇 |
2000年 | 291篇 |
1999年 | 288篇 |
1998年 | 206篇 |
1997年 | 219篇 |
1996年 | 176篇 |
1995年 | 146篇 |
1994年 | 172篇 |
1993年 | 133篇 |
1992年 | 198篇 |
1991年 | 138篇 |
1990年 | 168篇 |
1989年 | 131篇 |
1988年 | 146篇 |
1987年 | 82篇 |
1986年 | 107篇 |
1985年 | 103篇 |
1984年 | 98篇 |
1983年 | 91篇 |
1982年 | 61篇 |
1981年 | 49篇 |
1980年 | 39篇 |
1979年 | 31篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
目的 研究彩色多普勒超声诊断房间隔缺损(ASD)的准确性。方法 回顾性分析经手术证实的64例ASD患者的超声检查结果并和手术结果对照。结果 64例患者中有1例三房心合并房间隔缺损畸形,1例合并右下肺静脉异位引流漏诊,术前超声正确诊断63例,定性诊断准确率达98.4%,有1例混合型定位不准确,定位准确率在98.4%,而且64例患者中超声检查结果显示在无合并其他畸形时房间缺损大小与右心系统扩大及肺动脉扩张呈正相关关系。结论 ASD是以右室容量超负荷为特征,彩色多普勒超声是诊断房间隔缺损的首选检查方法,并具有较高的准确性。 相似文献
52.
Atrial fibrillation (AF) is the most common cardiac arrhythmia among the elderly. Its incidence increases dramatically with increasing age and decreasing left ventrieular function, peaking in subjects with overt congestive heart failure, Because of the unsatisfactory efficacy and possible serious side effects of clinically available anti-AF drugs for AF patients with sick sinus syndrome, pacing techniques have recently been applied in the treatment of AF. The cardiac pacemaker Vitatron 相似文献
53.
Jie Lian Dirk Müssig Volker Lang 《Europace : European pacing, arrhythmias, and cardiac electrophysiology》2007,9(7):506-513
AIMS: To quantitatively compare the ventricular rate-smoothing (VRS) effects of different ventricular pacing (VP) protocols for atrial fibrillation (AF). METHODS AND RESULTS: Using a recently developed open-source model that can simulate the ventricular response in AF and VP, the performance of fixed-rate pacing and four previously published VRS algorithms were assessed by the mean RR (mRR), the root mean square of successive RR differences (RMSSD), the percentage of ventricular senses (VS%), and the percentage of short RR intervals (sRR%). All pacing protocols cause rate-dependent reduction of RMSSD, VS%, and sRR% with or without shortening of mRR compared to spontaneous AF. Fixed-rate pacing was more sensitive to the intrinsic rate than the VRS algorithms. The performance was generally comparable between different VRS algorithms, although higher mRR and VS% can be achieved at the expense of larger RMSSD and sRR%. CONCLUSION: The effect of VP on ventricular rhythm in AF depends on both intrinsic rate and the aggressiveness of the pacing protocol. Adequate rate control is necessary for effective operation of the VRS algorithm. Choosing VRS algorithm should balance between the beneficial effects of rate regularization and the negative effects of increasing heart rate and percentage of VP. 相似文献
54.
55.
Hailong Tao Jianzeng Dong Ronghui Yu Changsheng Ma 《Journal of interventional cardiac electrophysiology》2007,19(1):41-43
Straight back syndrome (SBS) is a thoracic deformity with absence of upper thoracic spine kyphosis and heart compression.
The anatomic abnormity of SBS may raise the difficulty of introcardial operation and increase the complicated risk of intervention
performance. Here we report a case of SBS with complicated transseptal puncture during intervention catheter ablation of atrial
fibrillation. 相似文献
56.
Sunil Kumar Saxena S. Gopalakrishnan 《Indian journal of otolaryngology and head and neck surgery》2003,55(4):281-282
Despite the common occurrence of pleomorphic adenoma of major salivary glands, intranasal pleomorphic adenoma are rare. We
present a ease of pleomorphic adenoma of the nasal septum along with a brief review of literature. The histological nature
of this lesion in comparison to other salivary gland tumours and the importance of an accurate diagnosis has been stressed. 相似文献
57.
鼻内镜下鼻中隔成形术临床应用观察 总被引:1,自引:0,他引:1
目的探讨鼻内镜下鼻中隔成形术的优点.方法鼻内镜下行鼻中隔成形术50例,其中高位和后段偏曲6例.结果50例均一次完成手术,偏曲的鼻中隔均获得彻底矫正.手术时间30~72 min,平均48 min,偏进的鼻中隔获得彻底矫正,随访6~9个月,平均7.1月,治愈45例(90%),好转5例(10%).无鼻中隔血肿、脓肿、穿孔、鼻腔粘连、鼻梁塌陷等并发症发生.结论鼻内镜下鼻中隔成形术,手术时间短,术中出血少,疼痛轻,术后并发症少,可同期行鼻窦手术,完全可以取代传统的鼻中隔黏膜下切除术. 相似文献
58.
P. MORSING A. STENBERG D. CASELLAS A. MIMRAN C. MÜLLER-SUUR C. THORUP L. HOLM A. E. G. PERSSON 《Acta physiologica (Oxford, England)》1992,146(3):393-398
Atrial natriuretic peptide (ANP), injected at physiological concentrations, is known to induce both natriuresis and diuresis. It has been suggested by some investigators that these changes result from an increasing glomerular filtration rate (GFR), but others have been unable to demonstrate an increased GFR. The tubuloglomerular feedback (TGF) mechanism is an important regulator of GFR, and the sensitivity of TGF is decreased during ANP administration. Furthermore, resetting of TGF is, in most instances, related to changes in renal interstitial hydrostatic and oncotic pressures. It is also known that ANP may increase capillary permeability which may change renal interstitial pressure. The present study was performed to examine renal interstitial pressures and the TGF mechanism during ANP infusion. In accordance with previous studies, TGF sensitivity was found to be decreased. The tubular flow rate which elicited half the maximal drop in stop-flow pressure (Psf) was increased from 18.5 to 25.7 nl min-1. In contrast, ANP infusion resulted in a decreased interstitial hydrostatic pressure and an increased interstitial oncotic pressure. From previous experiments, such changes in interstitial pressures would be expected to increase TGF sensitivity. The changes in interstitial pressure cannot, therefore, directly explain the resetting of the feedback mechanism. In conclusion, the present paper shows a decreased renal net interstial pressure after intravenous administration of ANP. 相似文献
59.
射频消融迷宫术治疗心房纤颤 总被引:3,自引:0,他引:3
作者采用射频消融迷宫术治疗心房纤颤20例,其中19例合并风湿性二尖瓣病的患者,同时行瓣膜替换术,1例合并房间隔缺损患者进行修复。射频消融的路线采用小板井嘉夫的手术径路。术后16例恢复窦性心律,占80%,未恢复窦性心律的4例,2例为房颤,1例为房扑,另1例为结性心律。射频消融迷宫术耗时短,仅增加钳闭主动脉时间平均20.5分钟,无术后出血的潜在危险。但术后7~10天之内,有18例出现过房颤、房扑、房速等室上性心律失常,可能由于射频消融不均匀,干扰心房的心电活动所致。 相似文献
60.
小剂量氨茶碱治疗缓慢室率性房颤的长期疗效观察 总被引:1,自引:0,他引:1
目的研究小剂量氨茶碱对老年缓慢心室率性心房纤颤的长期疗效。方法15例有症状的老年缓慢心室率性房颤病人口服氨茶碱(150mg/d)。治疗前及治疗后第7天、第1、3、6、9及12个月行心电图及动态心电图检查。结果以均数±标准差表示,采用秩和检验分析差异显著性。结果治疗后第7天静息心率、24小时平均心率、最慢心率及最快心率分别增加38%(P<0.01)、28%(P<0.01)、26%(P<0.05)及16%(P<0.01),24小时>2500ms的心脏停搏次数减少94%(P<0.01),室性早搏次数增加6%,但差异不显著。随访12个月(中位数),各项参数与治疗后第7天的结果相似,临床症状明显减轻或消失。结论小剂量氨茶碱治疗老年缓慢心室率性房颤有效。 相似文献