全文获取类型
收费全文 | 135953篇 |
免费 | 11822篇 |
国内免费 | 3546篇 |
专业分类
耳鼻咽喉 | 587篇 |
儿科学 | 4010篇 |
妇产科学 | 1377篇 |
基础医学 | 9215篇 |
口腔科学 | 1625篇 |
临床医学 | 18922篇 |
内科学 | 40606篇 |
皮肤病学 | 936篇 |
神经病学 | 3153篇 |
特种医学 | 3021篇 |
外国民族医学 | 2篇 |
外科学 | 13960篇 |
综合类 | 23599篇 |
现状与发展 | 16篇 |
一般理论 | 6篇 |
预防医学 | 6838篇 |
眼科学 | 503篇 |
药学 | 12221篇 |
130篇 | |
中国医学 | 8693篇 |
肿瘤学 | 1901篇 |
出版年
2024年 | 124篇 |
2023年 | 2348篇 |
2022年 | 2858篇 |
2021年 | 5273篇 |
2020年 | 5798篇 |
2019年 | 5196篇 |
2018年 | 4926篇 |
2017年 | 4938篇 |
2016年 | 5007篇 |
2015年 | 5185篇 |
2014年 | 9541篇 |
2013年 | 10393篇 |
2012年 | 7876篇 |
2011年 | 8781篇 |
2010年 | 6918篇 |
2009年 | 6631篇 |
2008年 | 6425篇 |
2007年 | 6585篇 |
2006年 | 5934篇 |
2005年 | 5399篇 |
2004年 | 4323篇 |
2003年 | 3711篇 |
2002年 | 3260篇 |
2001年 | 2929篇 |
2000年 | 2360篇 |
1999年 | 2118篇 |
1998年 | 1712篇 |
1997年 | 1650篇 |
1996年 | 1403篇 |
1995年 | 1423篇 |
1994年 | 1366篇 |
1993年 | 1024篇 |
1992年 | 959篇 |
1991年 | 877篇 |
1990年 | 702篇 |
1989年 | 679篇 |
1988年 | 594篇 |
1987年 | 517篇 |
1986年 | 469篇 |
1985年 | 567篇 |
1984年 | 462篇 |
1983年 | 294篇 |
1982年 | 333篇 |
1981年 | 322篇 |
1980年 | 237篇 |
1979年 | 197篇 |
1978年 | 178篇 |
1977年 | 141篇 |
1976年 | 133篇 |
1975年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Rolf Svedjeholm Gabriele Ferrari Farkas Vanky Örjan Friberg Jonas Holm 《Acta anaesthesiologica Scandinavica》2023,67(10):1373-1382
Background
Glutamate plays a key role for post-ischaemic recovery of myocardial metabolism. According to post hoc analyses of the two GLUTAMICS trials, patients without diabetes benefit from glutamate with less myocardial dysfunction after coronary artery bypass surgery (CABG). Copeptin reflects activation of the Arginine Vasopressin system and is a reliable marker of heart failure but available studies in cardiac surgery are limited. We investigated whether glutamate infusion is associated with reduced postoperative rises of plasma Copeptin (p-Copeptin) after CABG.Methods
A prespecified randomised double-blind substudy of GLUTAMICS II. Patients had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0 and underwent CABG ± valve procedure. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was commenced 10–20 min before the release of the aortic cross-clamp and then continued for another 150 min P-Copeptin was measured preoperatively and postoperatively on day one (POD1) and day three. The primary endpoint was an increase in p-Copeptin from the preoperative level to POD1. Postoperative stroke ≤24 h and mortality ≤30 days were safety outcomes.Results
We included 181 patients of whom 48% had diabetes. The incidence of postoperative mortality ≤30 days (0% vs. 2.1%; p = .50) and stroke ≤24 h (0% vs. 3.2%; p = .25) did not differ between the glutamate group and controls. P-Copeptin increased postoperatively with the highest values recorded on POD1 without significant inter-group differences. Among patients without diabetes, p-Copeptin did not differ preoperatively but postoperative rise from preoperative level to POD1 was significantly reduced in the glutamate group (73 ± 66 vs. 115 ± 102 pmol/L; p = .02). P-Copeptin was significantly lower in the Glutamate group on POD1 (p = .02) and POD 3 (p = .02).Conclusions
Glutamate did not reduce rises of p-Copeptin significantly after moderate to high-risk CABG. However, glutamate was associated with reduced rises of p-Copeptin among patients without diabetes. These results agree with previous observations suggesting that glutamate mitigates myocardial dysfunction after CABG in patients without diabetes. Given the exploratory nature of these findings, they need to be confirmed in future studies. 相似文献2.
目的 运用标准化患者法评估四川农村地区基层医生不稳定型心绞痛和2型糖尿病两种慢性病诊断准确性现状,探讨基层医生两种慢性病诊断准确性的主要影响因素,为提升基层医生两种慢性病诊断准确性提供科学依据。方法 采用多阶段随机整群抽样方法,抽取四川省自贡市5个区/县50个乡镇100个村为研究现场,以调查当日在岗的全科及内科医生作为研究对象。共进行两轮数据采集,第1轮采集样本乡镇卫生院和村卫生室医生的基本信息;第1轮调查完成1个月后,运用标准化患者法开展第2轮调查,收集农村基层医生对不稳定型心绞痛和2型糖尿病诊断结果信息。运用Logistic回归分析农村基层医生不稳定型心绞痛和2型糖尿病诊断准确性的影响因素。结果 共纳入172名农村基层医生,完成186次标准化患者访问,正确诊断率为48.39%。其中不稳定型心绞痛的正确诊断率为18.68%(17/91),2型糖尿病的正确诊断率为76.84%(73/95)。Logistic回归分析显示,具有执业医师资质的农村基层医生更有可能做出正确诊断(OR=4.857,95%CI=1.076~21.933,P=0.040)。农村基层医生在诊断过程中涉及的必要问诊和检查条目越多,做出正确诊断的概率越高(OR=1.627,95%CI=1.065~2.485,P=0.024)。与不稳定型心绞痛相比,农村基层医生对2型糖尿病做出正确诊断的可能性更高(OR=6.306,95%CI=3.611~11.013,P<0.001)。结论 四川农村基层医生不稳定型心绞痛和2型糖尿病诊断准确性整体较差,建议以基层医生慢性病诊断过程质量改善为突破口,提升基层医生执业水平,进而提高慢性病诊断准确性。 相似文献
3.
4.
5.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):94-103.e24
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established. 相似文献
6.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):622-629.e2
ObjectiveDeterioration of the native aortic valve function by a late progression of rheumatic disease is not infrequent in patients who underwent rheumatic mitral valve surgery; however, this phenomenon has not been clearly quantified.MethodsA total of 1155 consecutive patients (age 52.0 ± 12.9 years; 807 female) who underwent rheumatic mitral valve surgery without concomitant aortic valve surgery from 1997 to 2015 were enrolled. The primary end point was the composite of progression to severe aortic valve dysfunction or a requirement of subsequent aortic valve replacements during follow-up. To determine the risk factors of the primary outcome, we performed the generalized linear mixed model.ResultsThe baseline severities of aortic valve were none to trivial in 880 patients (76.2%), mild in 256 patients (22.2%), and moderate in 19 patients (1.6%). The latest 1062 echocardiographic assessments (91.9%; median, 81.2 postoperative months; interquartile range, 37.3-132.1 months) demonstrated 26 cases (0.33%/patient-year) meeting the primary end point during follow-up. Cumulative incidence of the primary end point at 10 years was 0.4% ± 0.3% and 7.4% ± 2.5% depending on the presence of mild or greater aortic valve dysfunction at baseline (P < .01). In multivariable analyses, aortic valve peak pressure gradient (odds ratio, 1.14; 95% confidence interval, 1.10-1.20), aortic regurgitation degree (mild over none: odds ratio, 3.26; 95% confidence interval, 1.15-9.23), and time (odds ratio, 1.30; 95% confidence interval 1.19-1.41) were significantly associated with the occurrence of the primary end point.ConclusionsProgression of severe aortic valve dysfunction and the need for aortic valve replacement are uncommon in patients undergoing rheumatic mitral valve surgery. However, such events were relatively common among those with mild or greater aortic valve dysfunction at the time of mitral valve surgery. 相似文献
7.
目的 探讨氯雷他定联合阿伐斯汀治疗慢性难治性荨麻疹的效果及安全性。方法 选择2019年1月至2020年6月本院接收的慢性难治性荨麻疹患者85例,采用随机数字表法将其分为对照组(42例)和观察组(43例)。对照组采用阿伐斯汀胶囊口服治疗,在对照组基础上,观察组采用氯雷他定片口服治疗,治疗4周后,比较两组临床疗效、实验室相关指标[白细胞(WBC)、5-羟色胺(5-HT)、血清免疫球蛋白(IgE)]、安全性。结果 观察组临床总有效率(95.35%)高于对照组(78.57%),差异有统计学意义(χ2=5.308,P=0.021);治疗4周后,观察组5-HT水平(127.65±8.61)μg/L高于对照组的(104.52±9.32)μg/L,IgE水平(57.41±7.53)IU/mL、WBC水平(9.20±1.95)g/L低于对照组的(72.26±8.40)IU/mL、(11.31±2.04)g/L,差异有统计学意义(t=11.889、8.587、4.875,P均=0.000);观察组不良反应发生率(11.63%)与对照组(7.14%)对比,差异无统计学意义(χ2=0.501,P=0.713)。结论 予以慢性难治性荨麻疹患者氯雷他定联合阿伐斯汀治疗效果确切,可改善患者实验室相关指标,且未明显增加不良反应,安全性较高。 相似文献
8.
《Enfermería clínica》2022,32(3):171-183
IntroductionAgeing is a period of physical and psychological changes. Inactivity is one of the biggest problems among the older adult population increasing the risk of sarcopenia and chronic diseases. Physical activity is an effective intervention to improve health outcomes. In recent years, there has been an increase in the use of technology, with health technology tools (ICT) appearing as an intervention to increase physical activity and improve associated health problems.ObjectiveIn this review, we evaluated the effectiveness of health technology to increase physical activity and to improve cardiovascular parameters in older adults.MethodologyStudies with a great variety of health technology tools to increase physical activity levels, and that evaluated the effect of that increase on cardiovascular parameters were included by searching the main databases.ResultsEleven studies reporting the use of a variety of ICT tools were included in this review. Despite these differences, the effectiveness of health technology tool interventions has been demonstrated in increasing physical activity and reducing cardiovascular parameters.DiscussionThe lack of adherence of older adults to health technology would be a disadvantage, but it has been shown that younger older adults are more familiar with health technology tools and the number using them is increasing.ConclusionHealth technology tools show effectiveness in increasing physical activity in older adults and improving cardiovascular parameters. 相似文献
9.
《Journal of vascular and interventional radiology : JVIR》2022,33(12):1531-1535
This study investigated the role of dual-energy computed tomography (CT) for lesion characterization in patients with peripheral arterial disease manifesting with chronic total occlusions (CTOs). Forty-one symptomatic patients with CTOs underwent dual-energy CT angiography before endovascular treatment. The lesions were subsequently analyzed in a dedicated workstation, and 2 indexes—dual-energy index (DEI) and effective Z (Zeff)—were calculated, ranging from 0.0027 to 0.321 and from 6.89 to 13.02, respectively. Statistical analysis showed a significant correlation between the DEI and Zeff values (P < .001). The interobserver intraclass correlation coefficient was 0.91 for the mean Zeff values and 0.86 for the mean DEI values. This technique could potentially provide useful information regarding the composition of a CTO. 相似文献