全文获取类型
收费全文 | 14535篇 |
免费 | 1003篇 |
国内免费 | 205篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 478篇 |
妇产科学 | 203篇 |
基础医学 | 463篇 |
口腔科学 | 34篇 |
临床医学 | 3358篇 |
内科学 | 4069篇 |
皮肤病学 | 47篇 |
神经病学 | 376篇 |
特种医学 | 505篇 |
外国民族医学 | 1篇 |
外科学 | 1705篇 |
综合类 | 1978篇 |
预防医学 | 821篇 |
眼科学 | 32篇 |
药学 | 1243篇 |
11篇 | |
中国医学 | 117篇 |
肿瘤学 | 242篇 |
出版年
2024年 | 21篇 |
2023年 | 235篇 |
2022年 | 337篇 |
2021年 | 524篇 |
2020年 | 545篇 |
2019年 | 479篇 |
2018年 | 445篇 |
2017年 | 504篇 |
2016年 | 531篇 |
2015年 | 542篇 |
2014年 | 1085篇 |
2013年 | 1068篇 |
2012年 | 973篇 |
2011年 | 997篇 |
2010年 | 805篇 |
2009年 | 719篇 |
2008年 | 625篇 |
2007年 | 633篇 |
2006年 | 590篇 |
2005年 | 522篇 |
2004年 | 474篇 |
2003年 | 367篇 |
2002年 | 309篇 |
2001年 | 281篇 |
2000年 | 225篇 |
1999年 | 231篇 |
1998年 | 222篇 |
1997年 | 172篇 |
1996年 | 143篇 |
1995年 | 130篇 |
1994年 | 154篇 |
1993年 | 122篇 |
1992年 | 95篇 |
1991年 | 82篇 |
1990年 | 53篇 |
1989年 | 61篇 |
1988年 | 61篇 |
1987年 | 43篇 |
1986年 | 38篇 |
1985年 | 54篇 |
1984年 | 44篇 |
1983年 | 28篇 |
1982年 | 31篇 |
1981年 | 30篇 |
1980年 | 24篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 8篇 |
1976年 | 13篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
目的 观察应用尼卡地平预防双腔支气管导管插管心血管反应的效果。 方法 肺、食道择期手术病人 40例 ,随机分为 2组 ,每组 2 0例。咪唑安定 0 .0 4mg/kg、异丙酚 1.5mg/kg、芬太尼 4μg/kg、维库溴铵 0 .12mg/kg静脉诱导后 ,甲组给予尼卡地平 4μg/kg ,乙组给予生理盐水 3ml作为对照。分别于诱导前、后 ,插管后即刻及 1、3、5min监测收缩压 (SBP)、舒张压 (DBP)、心率 (HR) ,并计算心率收缩压乘积 (RPP)。 结果 A组插管后血压无明显升高 ,心率较诱导前无明显增快 ,B组插管后血压明显升高。 结论 尼卡地平可抑制双腔支气管导管插管时的心血管副反应。 相似文献
102.
目的:分析房室结慢径路消融术中出现的一过性交界性心律(JR)的特征。方法:21例(男6例,女15例)进行房室结改良术的房室结折返性心动过速患者,术中详细记录释放射频的次数、能量、持续时间、以及出现一过性交界性心律的时间、频率及数目,比较释放射频有效时/无效时出现的一过性交界性心律之特征有无显著性差异。结果:共进行106次射频电流释放,其中21次有效(A组),85次无效(B组)。A组有19次出现JR 相似文献
103.
目的:总结老年人急性心肌梗塞(AMI)静脉溶栓治疗经验。方法:对82例老年人AMI的临床资料及其中75例的溶栓治疗资料进行分析。结果:老年人AMI时,无胸痛史达54.9%,入院心电图ST-T缺乏典型改变占45.3%。经静脉溶栓治疗,梗塞动脉开通率为62.9%,与70岁以下AMI组溶栓开通率比较(65%),无统计学差异。结论:老年人AMI发病时,临床表现及心电图改变常不典型,应引起重视。在本文条件下 相似文献
104.
Darouiche RO Hampel OZ Boone TB Raad II 《International journal of antimicrobial agents》1997,8(4):243-247
The main objective of this study was to examine the antimicrobial activity and durability of a novel indwelling bladder catheter impregnated with minocycline and rifampin. Thirty antimicrobial-impregnated bladder catheters were inserted transurethrally in spinal cord-injured patients and removed, in six groups of five catheters each, at 3, 7, 10, 14, 17 or 21 days. Removed catheters had detectable zones of inhibition against two different clinical isolates of each of the 10 tested uropathogens (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter diversus, Enterococcus faecalis, Enterococcus faecium, Staphylococcus saprophyticus and Candida albicans) for greater than 14 days after catheter insertion. The residual zones of inhibition and levels of antimicrobial agents in removed catheters were both inversely related to the duration of catheter placement. Minocycline and rifampin were undetectable in serum and urine. These results support the ongoing efforts for examining the clinical efficacy of these experimental bladder catheters. 相似文献
105.
Modulation of immunoglobulin production and cytokine mRNA expression in peripheral blood mononuclear cells by intravenous immunoglobulin 总被引:1,自引:0,他引:1
Mieko Toyoda Xiaoming Zhang Anna Petrosian Odette A. Galera Sue-Jane Wang Stanley C. Jordan 《Journal of clinical immunology》1994,14(3):178-189
Intravenous immunoglobulin (IVIG) has the potential to regulate Ig production, but the mechanism(s) responsible for this effect is unknown. In experiments reported here, we examined the ability of IVIG to regulate Ig production in human peripheral blood mononuclear cells (PBMCs) stimulated with pokeweed mitogen (PWM). IVIG (2–10 mg/ml) showed a potent (80–85%) inhibition of PWM-stimulated IgG, IgM, and IgA production. To determine more precisely how IVIG mediated the inhibition of Ig production, we studied Ig promoting cytokine gene expression after PWM stimulation with or without IVIG (2 and 10 mg/ml) using dot-blot techniques. RNA was isolated from PBMCs at predetermined time points and probed with cDNAs specific for human cytokines (IL-1-, IL-2, IL-2R, IL-4, IL-5, IL-6, -IFN, and TNF-). IL-6 mRNA accumulation was maximal at 4.5 hr post-PWM stimulation and was inhibited 64–75% when IVIG (10 mg/ml) was present. -IFN mRNA levels peaked at 72 hr poststimulation and were also 68–75% inhibited by IVIG. IL-2 mRNA levels peaked at 4.5 hr and were 23–46% inhibited by IVIG. The inhibitory effect of IVIG on production of these cytokines (IL-6 and -IFN) was also observed at the protein level in sonicated PBMCs after incubation with PWM and IVIG. The mRNA levels for other cytokines were not or only minimally inhibited by IVIG. Addition of IL-6, -IFN, or IL-2 partially restored Ig production in IVIG-treated PWM-stimulated cultures, suggesting that inhibition of other cytokines or another mechanism(s) independent of cytokine inhibition might also be involved, although inhibition of IL-6, -IFN, and IL-2 may be one of the critical factors in the suppression of Ig production by IVIG. 相似文献
106.
The purpose of this case report is to describe the events, intervention, and aetiology which led to acute airway obstruction in an adult patient after the placement of a Hickman catheter. Airway obstruction secondary to superior vena cava obstruction occurred after placement of a subclavian vein Hickman catheter. This was felt to occur, in part, to a narrowed superior vena cava as evident by subclavian venography. It resulted in emergency oral tracheal intubation to relieve airway obstruction. Shortly after removal of the Hickman catheter, the signs of superior vena cava obstruction syndrome resolved and the patient was extubated without incidence. It is concluded that, although rare, the serious complication of acute airway obstruction can occur after placement of a Hickman catheter. 相似文献
107.
Antonino Salvaggio 《European journal of epidemiology》1995,11(2):127-131
We present a model to estimate the infection curve of the human immunodeficiency virus in intravenous drug users in Lombardia. We based estimates on AIDS incidence data, according to a backcalculation model accounting for therapy and changes in the surveillance definition of AIDS. 相似文献
108.
《Seminars in Pediatric Surgery》2022,31(3):151181
Advancements in donor management, organ preservation and operative techniques, as well as immunosuppressive therapies, have provided children with intestinal failure and its complications a chance not only for enteral autonomy but also long-term survival through intestinal transplantation (ITx). First described in the 1960’s, experience has grown in managing these complex patients both pre- and post-transplant. The goals of this review are to provide a brief history of intestinal transplantation and intestinal rehabilitation in pediatric patients, followed by focused discussions of the indications for ITx, induction and maintenance immunosuppression therapies, common post-operative complications, and outcomes/quality of life post-transplant. 相似文献
109.
Hettrick DA Battocletti J Ackmann J Warltier DC 《Annals of biomedical engineering》1999,27(2):151-159
Traditional methods for estimating the slope and offset volume V
P
for determining real-time chamber volume by the conductance catheter technique are not suited to measurements made in the aorta due to the relatively low resistivity of the aortic wall. We developed three distinct three-dimensional finite element models of the conductance catheter and surrounding tissues in order to predict and V
P
and to examine the nature of the electric field near the aortic wall. A heterogeneous isotropic model of the catheter, aorta and surrounding tissues accurately predicted the values of and V
P
. A homogeneous anisotropic model was developed to examine the effects of anisotropy of blood and the layers of the aortic wall on measured values of resistance, and V
P
. This model demonstrated that anisotropy of blood and aortic wall tissue can increase the values of both and V
P
. Finally, a three-dimensional homogeneous isotropic rectangular model allowed examination of the effects of catheter position. This model showed small effects of catheter position on measured resistance (9.7% increase) and larger effects on (21.2% decrease) and V
P
(41.9% increase). We conclude the following: the FEA models may lead to accurate estimate values of and V
P
in vivo. The unique anisotropic conductive properties of the layers of the aortic wall contribute to the high observed values of and V
P
in the aorta. Finally, catheter position has a proportionately greater effect on and V
P
than on measured resistance. The results of this study should assist in the determination of aortic mechanical properties using conductance catheter measurements of vessel dimension. © 1999 Biomedical Engineering Society.
PAC99: 8719Nn, 8719Rr, 8719Uv, 0270Dh, 8717Aa 相似文献
110.
目的:探讨房室结折返性心动过速(AVNRT)射频消融术后的电生理改变及不同手术终点与复发率的关系。 方法:本组56 例AVNRT患者慢径消融前、后作各项电生理参数测定,并随访观察远期疗效。 结果:38 例慢径消失者(A组)无一例复发,残存慢径12 例(B组)有一例复发(8.33% ),残存慢径有1~2 个心房回波者6例(C组)有2例复发(33.3% )。53 例无复发者消融前后的房室束最大值(A-Hm ax )分别为(280±27)和(196±56)m s(P<0.01),快径不应期分别为(330±44)和(287±31)m s(P< 0.01)。而3 例复发者消融前、后的A-Hm ax分别为(287±31)和(262±38)m s(P> 0.05),快径不应期分别为(324±38)和(313±28)m s(P> 0.05)。 结论:AVNRT的复发与慢径残存和A-Hm ax 及快径不应期无明显改变有关。 相似文献