全文获取类型
收费全文 | 18877篇 |
免费 | 1213篇 |
国内免费 | 806篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 331篇 |
妇产科学 | 133篇 |
基础医学 | 1258篇 |
口腔科学 | 81篇 |
临床医学 | 2885篇 |
内科学 | 4243篇 |
皮肤病学 | 56篇 |
神经病学 | 448篇 |
特种医学 | 1431篇 |
外国民族医学 | 3篇 |
外科学 | 3594篇 |
综合类 | 2902篇 |
现状与发展 | 1篇 |
预防医学 | 412篇 |
眼科学 | 1047篇 |
药学 | 1120篇 |
9篇 | |
中国医学 | 388篇 |
肿瘤学 | 495篇 |
出版年
2024年 | 41篇 |
2023年 | 298篇 |
2022年 | 493篇 |
2021年 | 683篇 |
2020年 | 662篇 |
2019年 | 597篇 |
2018年 | 540篇 |
2017年 | 590篇 |
2016年 | 608篇 |
2015年 | 642篇 |
2014年 | 1157篇 |
2013年 | 1186篇 |
2012年 | 1092篇 |
2011年 | 1184篇 |
2010年 | 1030篇 |
2009年 | 1019篇 |
2008年 | 1063篇 |
2007年 | 1041篇 |
2006年 | 997篇 |
2005年 | 849篇 |
2004年 | 714篇 |
2003年 | 578篇 |
2002年 | 515篇 |
2001年 | 421篇 |
2000年 | 354篇 |
1999年 | 305篇 |
1998年 | 296篇 |
1997年 | 300篇 |
1996年 | 190篇 |
1995年 | 188篇 |
1994年 | 178篇 |
1993年 | 138篇 |
1992年 | 118篇 |
1991年 | 102篇 |
1990年 | 75篇 |
1989年 | 67篇 |
1988年 | 80篇 |
1987年 | 60篇 |
1986年 | 63篇 |
1985年 | 70篇 |
1984年 | 45篇 |
1983年 | 27篇 |
1982年 | 45篇 |
1981年 | 47篇 |
1980年 | 31篇 |
1979年 | 39篇 |
1978年 | 22篇 |
1977年 | 18篇 |
1976年 | 14篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
A Decrease in Pulmonary Vein Diameter After Radiofrequency Ablation Predicts the Development of Severe Stenosis 总被引:3,自引:0,他引:3
ALEXANDER BERKOWITSCH THOMAS NEUMANN OKAN EKINCI HARALD GREISS THORSTEN DILL KLAUS KURZIDIM MALTE KUNISS HANS J. SCHNEIDER HEINZ F. PITSCHNER 《Pacing and clinical electrophysiology : PACE》2005,28(S1):S83-S85
A decrease in ostial pulmonary vein (PV) diameter was observed in patients on the day after radiofrequency ablation of atrial fibrillation (AF). This study examined whether a relative reduction in PV diameter on day 1 (RRPVD1) after the procedure predicts the late development of severe PV stenosis (PVS). The study included 104 consecutive patients (mean age = 55 years, range 46–61, 34 women) with drug refractory AF. Pulmonary vein diameter was measured using MR angiography (MRA) on the day before and on day 1 after the ablation procedure. The MRA was repeated every 3 months after the procedure. Severe PVS was defined as a >70% diameter reduction from the initial ostial diameter. The cut-off of RRPVD1 was prespecified as 25% decrease in initial diameter. The data are presented as medians and interquartile range. A total of 357 PV were treated. The RRPVD1 was 0.0% (0.0–11.1%). Severe PVS was found in 18 PV during a follow-up of 12 months (range 6–13). The log-rank analysis confirmed a strong association between a RRPVD1 ≥25% and the development of PVS (hazard ratio: 7.1; 95% confidence interval 3.8–13.5, P < 0.0001). By multivariate Cox regression model, after adjustment of procedure variables, RRPVD1 was the strongest predictor of development of severe PVS. RRPVD1 ≥25% was a strong independent predictor of development of severe PVS. 相似文献
92.
93.
P Peters F A Flachskampf S Hauptmann H B Lo C J Schuster 《European heart journal》1992,13(11):1585-1588
Cardiac malignant mesenchymoma is an extremely rare malignancy with poor prognosis. We report a patient presenting with a history and clinical findings typical of mitral stenosis. Transthoracic echocardiography showed a mass on the thickened posterior mitral leaflet. Transoesophageal echocardiography revealed two tumoural masses: one on the atrial side of the posterior mitral leaflet causing mitral obstruction, the other arising in the region of the right lower pulmonary vein orifice and obstructing inflow through this vein. 相似文献
94.
肾病综合征合并肾静脉血栓形成:病因及抗栓治疗进展 总被引:1,自引:0,他引:1
肾病综合征患者具有明显的高凝倾向,肾静脉血栓形成是其常见且严重的并发症之一。文中阐述了肾病综合征患者高凝状态的病理生理学基础,对肾静脉血栓的抗栓治疗也做了详尽的综述。 相似文献
95.
目的 :探讨肝硬化门脉高压病人门静脉和肝动脉彩色多谱勒血流参数变化的意义。方法 :肝硬化伴食道静脉曲张的病人 6 6例 ,正常人对照组 5 8例。测量门静脉血流速度 (PVV)和肝动脉阻力参数 (HA- PI) ,计算肝血管指数。结果 :在肝硬化门脉高压病人比对照组 PVV明显降低 (12± 2 .2 ) cm/ s;(15 .8± 2 .6 ) cm/ s,P<0 .0 0 1)和 HA- PI明显增高(1.3± 0 .15 ;0 .94± 0 .16 ,P<0 .0 0 1) ,肝血管指数明显减低 [(8.6± 2 .1) cm/ s;(16 .7± 4 .2 ) cm / s,P<0 .0 0 1) ]。彩色多谱勒血流参数 PVV、HA- PI、肝血管指数对肝硬化门脉高压的诊断的敏感性和特异性分别为 89%、84 %、83%、81%、95%、91%。结论 :肝血管指数对肝硬化门脉高压的诊断的敏感性和特异性更高。 相似文献
96.
目的观察地塞米松(DEX)对内毒素(LPS)作用于人脐静脉内皮细胞(HUVEC)后表达组织因子(TF)、凝血酶调节蛋白(TM)和蛋白S(PS)的影响.方法24孔板培养的第1~5代HUVEC,在含不同浓度LPS和DEX的无血清培养基中培养一定时间后裂解细胞,应用酶联免疫吸附法(ELISA)测定裂解液中的TF、TM和PS含量.结果在LPS刺激下,HUVEC表达TF的量呈剂量依赖性升高,在LPS0.1μg/ml下TF的表达量为对照组的4倍(P<0.01),同时加入0.5 μg/ml和1.0 μg/ml DEX则可使TF的表达量由128.3±25.7 pg/105细胞分别降至94.9±19.4 pg/105细胞和98.8±7.8 pg/105细胞(P<0.05);LPS(0.01~10μg/ml)可抑制HUVEC表达TM,在LPS 10 μg/ml下,TM表达量降至对照组的60%(P<0.05).DEX可拮抗LPS抑制HUVEC表达TM的效应,0.1 μg/ml、0.5 μg/ml和1.0 μg/ml DEX可使LPS(10 μg/ml)作用下TM的表达量由0.282±0.014 ng/105细胞分别增至0.409±0.009、0.462±0.017和0.362±0.019 ng/105细胞(P<0.05);LPS(0~10 μg/ml)可抑制HUVEC表达PS,在LPS浓度1.0 μg/ml及10 μg/ml时,PS的表达量分别为对照组的43%和38%(P<0.01).DEX则拮抗LPS抑制HUVEC表达PS的效应,0.5 μg/ml DEX可使LPS刺激下PS的表达量由13.1±4.8%/2×105细胞增至48.5±10.2%/2×105细胞(P<0.01).结论LPS促进HUVEC表达TF,抑制HUVEC表达TM和PS.DEX能部分拮抗上述作用,提示DEX可能纠正内毒素血症时的高凝状态. 相似文献
97.
Day-only admissions for surgery are strongly encouraged, in an effort to keep costs down. Varicose vein surgery has been considered too major for day-only management despite the fact that there have been studies from overseas showing that it can be done with a morbidity comparable to inpatient surgery. The morbidity of day-only surgery for varicose veins (both long and short saphenous procedures) was assessed and compared with the results of inpatient surgery. Patients were also asked whether they were satisfied with the surgery being done this way. There were 165 consecutive patients available for study, 64 day-only and 101 inpatient. All patients attending Shellharbour Hospital, Shellharbour, had surgery done as day-only (as it was a morning list and allowed adequate time for recovery). Patients attending Bulli Hospital, Bulli, had surgery done as an inpatient (afternoon list). All surgery was performed by one surgeon. There was no difference (Chi-squared) in the age distribution (mean 48 years for day-only, 51 years for inpatient) or sex proportion in either group (Chi-squared test of proportions with continuity correction). Assessment of the results was done by review of the surgeon's notes, as well as telephone interviews for day-only subjects. The complication rate in both groups was similar. Wound problems represented the main complication with an incidence of 10.5% in each group. There was one deep venous thrombosis (DVT) in each group (diagnosed by duplex scan). Response to the telephone interview suggested that most patients were happy to have the surgery done as a day-only procedure. Sixty-nine per cent responded that they would have it done this way again and 76% were satisfied with the result of the surgery. This study confirms the results of overseas studies, in that varicose vein surgery can be performed as day-only procedures with a complication rate similar to inpatient procedures and with a high degree of patient satisfaction. It is suggested that this should be used as the method of choice for the majority of patients requiring varicose vein surgery. 相似文献
98.
伤肢小隐静脉修复腘动脉损伤解剖基础与临床应用 总被引:1,自引:0,他引:1
目的:为利用伤肢小隐静脉修复腘动脉损伤提供解剖学依据。方法:对25具标本50侧肢体的腘动脉和小隐静脉进行解剖研究并分别测量其管径。结果:腘动脉与小隐静脉解剖关系恒定,腘动脉管径起始段为(6.6±0.9)mm,中段为(5.9±1.0)mm,分叉前为(4.9±0.9)mm,小隐静脉管径汇入处为(3.1±0.1)mm,外踝平面和中段管径均为(2.9±0.1)mm,在小腿的上段小隐静脉与大隐静脉和深静脉间交通支出现率低。结论:腘动脉与小隐静脉解剖关系恒定,管径较相近,在伤肢小腿的上段切取一段小隐静脉对静脉回流无明显影响,临床应用21例22侧肢体,效果可靠满意。 相似文献
99.
N Roukounakis S Dimas I Kafetzis S Bethanis N Gatsulis H Kostas V Kyriakou S Michas 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(2):215-218
BACKGROUND AND OBJECTIVE: Adrenal tissue-sparing or partial adrenalectomy evolved initially for patients with bilateral synchronous adrenal surgical pathology to preserve vital adrenal volume. In the laparoscopic era, the exact criteria for performing such procedures laparoscopically have yet to be defined. Controversy exists regarding the importance of preserving the adrenal vein, main or accessory. The aim of this retrospective study was to present our short series of laparoscopic tissue-sparing adrenalectomies with vein preservation. Our main goal is not to support partial adrenalectomy as an alternative to total (this is already advocated by many surgeons) but to emphasize the vein-preserving technique. METHODS: Seven patients with peripherally located either aldosterone-producing adenomas (4 cases) or myelolipomas (4 cases) underwent laparoscopic lateral partial adrenalectomy. One patient harbored an aldosterone-producing adenoma and a myelolipoma as well. The main adrenal vein was identified and preserved in 6 patients and the accessory vein in one. RESULTS: No conversion to open adrenalectomy was necessary, and no perioperative morbidity or mortality occurred. Three adenoma patients are normotensive 44, 23, and 20 months postoperatively, while the fourth one's pressure is refractory. CONCLUSIONS: Surprisingly, total adrenalectomies preceded the partial ones, which is controversial compared with other procedures. Laparoscopic lateral partial adrenalectomy is a technically challenging tissue-sparing operation. Meticulous dissection allows preservation of the middle artery and main or accessory vein resulting in a functioning adrenal stump. 相似文献
100.