全文获取类型
收费全文 | 19775篇 |
免费 | 1578篇 |
国内免费 | 494篇 |
专业分类
耳鼻咽喉 | 309篇 |
儿科学 | 323篇 |
妇产科学 | 365篇 |
基础医学 | 844篇 |
口腔科学 | 243篇 |
临床医学 | 2770篇 |
内科学 | 1437篇 |
皮肤病学 | 82篇 |
神经病学 | 819篇 |
特种医学 | 357篇 |
外科学 | 4862篇 |
综合类 | 3631篇 |
预防医学 | 1526篇 |
眼科学 | 201篇 |
药学 | 2208篇 |
43篇 | |
中国医学 | 962篇 |
肿瘤学 | 865篇 |
出版年
2024年 | 70篇 |
2023年 | 384篇 |
2022年 | 755篇 |
2021年 | 905篇 |
2020年 | 1009篇 |
2019年 | 696篇 |
2018年 | 623篇 |
2017年 | 710篇 |
2016年 | 792篇 |
2015年 | 776篇 |
2014年 | 1678篇 |
2013年 | 1392篇 |
2012年 | 1518篇 |
2011年 | 1473篇 |
2010年 | 1185篇 |
2009年 | 1011篇 |
2008年 | 968篇 |
2007年 | 927篇 |
2006年 | 786篇 |
2005年 | 664篇 |
2004年 | 495篇 |
2003年 | 471篇 |
2002年 | 420篇 |
2001年 | 292篇 |
2000年 | 218篇 |
1999年 | 211篇 |
1998年 | 149篇 |
1997年 | 115篇 |
1996年 | 93篇 |
1995年 | 107篇 |
1994年 | 103篇 |
1993年 | 60篇 |
1992年 | 60篇 |
1991年 | 69篇 |
1990年 | 58篇 |
1989年 | 60篇 |
1988年 | 60篇 |
1987年 | 44篇 |
1986年 | 65篇 |
1985年 | 63篇 |
1984年 | 48篇 |
1983年 | 19篇 |
1982年 | 30篇 |
1981年 | 41篇 |
1980年 | 35篇 |
1979年 | 28篇 |
1978年 | 21篇 |
1977年 | 20篇 |
1976年 | 31篇 |
1975年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
71.
目的 研究胃癌根治术病人围手术期异体输血外周血单核细胞(PBMCs)白细胞分化抗原40配体(CD40L)表达的变化。方法 胃癌根治术病人30例,随机分为3组,每组10例。A组围术期不输血,B组围术期输入去白细胞的全血,C组围术期输入异体全血。另选10例健康人作为对照。分别在手术前、术后2、5、10 d采外周静脉血5 ml,用Ficoll分离液梯度离心法分离出PBMCs和血浆,将PBMCs置于自身血浆环境中,并在植物血凝素(PHA,20 mg/L)的刺激下进行培养,48 h后收获细胞,用流式细胞术检测CD40L表达。结果 健康人外周血未受PHA刺激时检测不到CD40L的表达,经PHA刺激后CD40L 细胞占CD4 T细胞的百分数为1.7%±0.4%,与三组胃癌病人术前比较差异无显著性(P>0.05)。与术前比较,B组术后2 d PBMCs CD40L表达升高(P<0.05),C组术后各时点升高(P<0.05);与A组比较,B组术后2 d升高(P<0.05),C组术后各时点升高(P<0.05);与B组比较,C组术后各时点升高(P<0.05)。结论 围手术期异体输血可造成免疫抑制,输异体血后CD40L表达增加,且输全血比输去白细胞的全血更明显。围手术期成分输血优于输注全血。 相似文献
72.
低体重先天性心脏病婴幼儿术后监护体会 总被引:1,自引:0,他引:1
目的 探讨低体重婴幼儿先天性心脏病的术后监护方法,以提高手术成功率。方法对142例15kg以下的先天性心脏病低体重婴幼儿(3岁以下)术后根据其生理特点,严密做好循环系统、呼吸系统、引流管、感染等监护措施,防止相关并发症的发生。结果 全组术后住院死亡6例,死亡率4.2%;术后并发症15例,发生率为10.6%,包括低心排出量综合征、呼吸衰竭、心律失常、肺部感染、出血等。结论 婴幼儿先天性心脏病术后根据其生理特点进行循环系统、呼吸系统、引流管、感染等监护,可有效降低术后并发症的发生,是提高手术成功率和治愈率的关键。 相似文献
73.
目的探讨闭合性脑外伤患者恢复后期的记忆障碍特点。方法用临床记忆量表对 2 0例闭合性脑外伤患者恢复后期及 2 0例正常人进行记忆测验。结果闭合性脑外伤患者恢复后期 5项分测验及记忆商均明显低于正常人对照组 ,MQ≤ 79的比例较正常人明显增高。结论闭合性脑外伤患者恢复后期有非常严重的记忆障碍 ,其回忆比再认受损更严重 相似文献
74.
Stimulation of mediocaudal midbrain in rats produces ipsiversive circling due to the stimulation of longitudinal axons. The refractory periods of these axons were measured by delivering trains of conditioning and testing pulses via a single electrode at various conditioning-testing (C-T) intervals. As C-T interval increased from 0.3 to 2.0 ms, the frequency required to produce a constant amount of circling halved. The current-distance relations of these axons were measured by placing two electrodes lateral to one another, and delivering conditioning pulses via one electrode and testing pulses via the second electrode. The required frequency decreased less at C-T intervals in the refractory period range using two electrodes rather than using a single electrode. This partial refractoriness suggests that only part of the axons were stimulated by both electrodes. The refractoriness increased as current increased or as interelectrode distance decreased. The overlap in the fields of stimulation at each current was calculated from the refractoriness observed in single and double electrode experiments. The results suggest that the axons mediating circling have a wide range of thresholds rather than a single threshold. The current required to activate an axon is roughly equal to K X r2, were K is a constant and r is the radial distance from electrode to axon. K must range from 400 to at least 3000 microA/mm2, to account for the circling data. For axons mediating medial forebrain bundle self-stimulation3, K must range from 1000 to at least 6400 microA/mm2. Estimation of the K distribution allows calculation of the effects of electrode size, placement and current on the recruitment of axons with different thresholds. 相似文献
75.
Summary Bronchus stump insufficiency following lung resection, with an average incidence of 4%, is a serious complication which carries a mortality of up to 90%. Operative transthoracic approaches have been largely unsatisfactory because of the high operative risk and rapidly spreading infection. In an experimental study on 18 pigs, endoscopic occlusion of infected bronchus stump fistulae was achieved with fibrin sealant (1 ml, 500 units/ml thrombin, 3500 units/ml aprotinin) applied via a flexible bronchoscope. During autopsy, all bronchus stump fistulae were found to have healed after the second postoperative week. Transitory local abscesses of the pleura could be prevented by high-dose systemic antibiotic therapy for 5 postoperative days but not by antibiotics added to the fibrin sealant. This endoscopic method has already been performed successfully in 3 clinical cases; additional sclerotherapy with (2–3 ml Ethoxysclerol applied around the fistula orifice was carried out before fibrin sealing to stimulate fibrosis. Endoscopic controls demonstrated fistula closure by granulation tissue after 2 weeks. This procedure could become the method of choice for infected postoperative fistulae of the bronchus stump and should be attempted in any case before operative approaches are considered. 相似文献
76.
R. Grundmann U. Szillat 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1989,374(2):84-91
Zusammenfassung Über ein Jahr wurden 1082 allgemeinchirurgische Planeingriffe prospektiv konsekutiv erfaßt und ihre Komplikationen mit einem Score bewertet. EinflußgröBen und die Komplikationsraten, die unter Umständen von der Kliniks-organisation abhängig sind, sollten analysiert werden. Es fand sich eine Beziehung zwischen Komplikationen und Wochentag, Operationsdauer sowie der Abweichung der tatsächlich benötigten von der geplanten Operationszeit. Mit höherer Auslastung der Operationssäle pro Arbeitstag stiegen die Komplikationsraten ebenfalls an.Keinen Einfluß auf die Komplikationsraten hatten Operationsbeginn und-monat sowie die monatliche Auslastung der Säle. Ob das Wetter einen Einfluß auf die Komplikationsraten nahm, konnte nicht entschieden werden: so fanden sich im Sommer- höhere Komplikationsraten als im Winterhalbjahr, jedoch war der Score von der Höhe der Außentemperatur und der Luftfeuchtigkeit unabhängig.
The influence of time of operation and hospital organization on postoperative complication rates
Summary During a 1-year period 1082 general surgical interventions were prospectively documented and their complication rates evaluated by a score system. Factors responsible for the complication rates and possibly depending on hospital organization should be analysed. The complication rates were influenced by the selection of the weekday, the length of operation time and the extent of discrepancy between planned and required operation time. Furthermore, the complication rates paralleled the extent of utilization of the operation theatre during a workday. The complication rates werenot affected by the beginning of operation and the operation month as well as the monthly utilization of the operation theatres. Whether the weather did influence the complication rates could not be decided: higher complication rates were found in the summer as compared to the winter period, but the complication score was independent of the level of the outside temperature and humidity.相似文献
77.
乙状结肠两种造口方式术后排便功能及并发症的观察和对比 总被引:3,自引:0,他引:3
目的对两种乙状结肠造口术后造口功能及并发症进行观察对比。方法回顾性分析我们自1996年~2006年行Miles手术腹壁永久性造口512例的临床资料。结果经腹膜外结肠造口288例,发生造口并发症23例,并发症发生率为7.99%;经腹膜内结肠造口224例,发生造口并发症76例,并发症发生率为33.93%。经腹膜外结肠造口者术后2年造口功能优良率为56.25%,经腹膜内结肠造口者为30.80%(P<0.01)。结论经腹膜外结肠造口功能恢复及术后并发症发生率均优于经腹膜内结肠造口。 相似文献
78.
1142例胃癌切除术围手术期死亡因素分析 总被引:11,自引:0,他引:11
目的研究影响胃癌围手术期死亡的主要因素,为指导选择合理的切除范围和手术方式提供依据。方法回顾1989年1月至2004年3月胃癌手术后1142例患者的临床资料,按照不同年代分为3组,第1组:1989年1月至1994年1月,405例;第2组:1994年2月至1999年1月,377例;第3组:1999年2月至2004年3月,360例。比较3组间的围手术期死亡率,采用Logistic多因素回归分析研究影响手术死亡率的危险因素。结果全组患者术后并发症发生率和死亡率分别为11.2%(128/1142)和3.6%(41/1142)。第1、2、3组的术后并发症发生率依次为13.1%、10.1%和10.3%;3组比较,P>0.05。3组手术死亡率依次为4.7%、3.4%和2.5%,3组比较,P>0.05。术后最常见的并发症是吻合口瘘(24.2%,31/128),影响手术死亡的主要因素为临床Ⅳ期、姑息性切除术、联合脏器切除及术前合并症的存在(P<0.05)。Logistic多元回归分析显示淋巴结的清除范围和手术方式不是影响手术死亡的主要因素(P>0.05)。结论胃癌晚期患者手术死亡率高,对胃癌Ⅳ期患者行姑息性切除手术时应避免施行不必要的淋巴结清除及联合脏器切除术。 相似文献
79.
Aims and Objectives The significance of beaten copper appearance (BCA) on skull radiographs in children following surgery for isolated sagittal
craniosynostosis has not been studied. This study was designed to look for any correlation between BCA and symptoms suggestive
of intracranial hypertension in this group of patients.
Materials and Methods Forty-eight consecutive children, who were operated for isolated sagittal synostosis from1987 to 2000 and had postoperative
skull radiographs, were included. Patients were divided into: (a) BCA group (n = 20), consisting of children who had beaten copper appearance on skull radiographs at last follow up, and (b) Non-BCA group
(n = 28), consisting of children who did not have this finding. Records were reviewed to look for symptoms suggestive of intracranial
hypertension, such as headache, head banging, and irritability.
Results Median age at surgery was 4.8 months for BCA group and 4 months for the non-BCA group. Follow up ranged from 4 to 156 months
with a mean of 36.2 months. Total of 28.6% (n = 6) of the children with follow up radiographs done at ≤18 months of age had BCA. The incidence of BCA increased to 83.3%
in children with skull radiographs performed after 48 months of age. In 18 (90%) children, the BCA was ‘diffuse’ with 5 (25%)
children having the maximum possible score of 8. In the BCA group, 45% (n = 9) had symptoms compared to 10.7% (n = 3) in the control group (p = 0.0068).
Conclusions This study suggests a significant number of children with BCA on radiographs develop symptoms suggestive of raised ICP following
surgical treatment in infancy and prolonged follow up may be warranted in this group of patients. 相似文献
80.
目的评价MRCP在诊断原位肝移植术后胆道并发症中的临床应用价值。方法分析63例肝移植术后怀疑有胆道并发症患者的MRCP图像,并与手术、胆道造影、临床随访证实结果进行对照。所有病例均在高场强1.5T磁共振上进行。MRCP采用两种不同的成像方法:厚层块T2加权成像和薄层块多层T2加权成像。结果MRCP诊断移植术后胆道并发症的敏感性为95.3%(41/43),阳性预测值97.6(41/42),假阴性率为4.54%(2/44),假阳性率为2.27%(1/44)。总诊断准确率为95.2%(60/63)。MRCP作为唯一的诊断方法能为96.8%(61/63)的患者提供特异性诊断结果,仅2例患者需要ERCP和PTHC检查3.2%(2/63)。直接胆道造影作为一项治疗手段应用于22.2%(14/63)的患者中。结论MRCP是评价肝移植术后胆道并发症的有效影像学方法。 相似文献