全文获取类型
收费全文 | 78108篇 |
免费 | 4050篇 |
国内免费 | 2223篇 |
专业分类
耳鼻咽喉 | 355篇 |
儿科学 | 1094篇 |
妇产科学 | 788篇 |
基础医学 | 4940篇 |
口腔科学 | 312篇 |
临床医学 | 10719篇 |
内科学 | 21010篇 |
皮肤病学 | 114篇 |
神经病学 | 4699篇 |
特种医学 | 6796篇 |
外国民族医学 | 2篇 |
外科学 | 10290篇 |
综合类 | 13077篇 |
现状与发展 | 3篇 |
预防医学 | 2253篇 |
眼科学 | 515篇 |
药学 | 4833篇 |
49篇 | |
中国医学 | 1908篇 |
肿瘤学 | 624篇 |
出版年
2024年 | 75篇 |
2023年 | 955篇 |
2022年 | 1655篇 |
2021年 | 2863篇 |
2020年 | 2619篇 |
2019年 | 2219篇 |
2018年 | 2224篇 |
2017年 | 2049篇 |
2016年 | 2142篇 |
2015年 | 2507篇 |
2014年 | 5338篇 |
2013年 | 5112篇 |
2012年 | 4523篇 |
2011年 | 4971篇 |
2010年 | 4210篇 |
2009年 | 4228篇 |
2008年 | 4406篇 |
2007年 | 4367篇 |
2006年 | 4068篇 |
2005年 | 3376篇 |
2004年 | 2779篇 |
2003年 | 2355篇 |
2002年 | 1954篇 |
2001年 | 1803篇 |
2000年 | 1405篇 |
1999年 | 1177篇 |
1998年 | 1139篇 |
1997年 | 1047篇 |
1996年 | 807篇 |
1995年 | 790篇 |
1994年 | 672篇 |
1993年 | 585篇 |
1992年 | 527篇 |
1991年 | 452篇 |
1990年 | 372篇 |
1989年 | 323篇 |
1988年 | 309篇 |
1987年 | 293篇 |
1986年 | 228篇 |
1985年 | 268篇 |
1984年 | 225篇 |
1983年 | 120篇 |
1982年 | 189篇 |
1981年 | 146篇 |
1980年 | 111篇 |
1979年 | 101篇 |
1978年 | 82篇 |
1977年 | 61篇 |
1976年 | 44篇 |
1975年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
J.A. Hannam S.J. Mitchell D. Cumin C. Frampton A.F. Merry M.R. Moore C.J. Kruger 《British journal of anaesthesia》2019,122(2):198-205
Background
Etomidate is frequently selected over propofol for induction of anaesthesia because of a putatively favourable haemodynamic profile, but data confirming this perception are limited.Methods
Patients undergoing cardiac surgery were randomised to induction of anaesthesia with propofol or etomidate. Phase I (n=75) was conducted as open-label, whereas Phase II (n=75) was double blind. Mean arterial blood pressure (MAP) and boluses of vasopressor administered after induction were recorded. The primary endpoint was the area under the curve below baseline MAP (MAP-time integral) during the 10 min after induction. Secondary endpoints were the use of vasopressors over the same period, and the effect of blinding on the aforementioned endpoints. Groups were compared using regression models with phase and anaesthetist as factors.Results
The mean difference between etomidate and propofol in the MAP-time integral below baseline was 2244 mm Hg s (95% confidence interval, 581–3906; P=0.009), representing a 34% greater reduction with propofol. Overall, vasopressors were used in 10/75 patients in the etomidate group vs 21/75 in the propofol group (P=0.38), and in 20/74 patients during the blinded phase vs 11/76 during the open-label phase (P=0.31). The interaction between randomisation and phase (open-labelled or blinded) was not significant for either primary (P=0.73) or secondary endpoints (P=0.90).Conclusions
Propofol caused a 34% greater reduction in MAP-time integral from baseline after induction of anaesthesia than etomidate, despite more frequent use of vasopressors with propofol, confirming the superior haemodynamic profile of etomidate in this context. The proportion of patients receiving vasopressors increased slightly, albeit not significantly, in both groups in the blinded phase.Clinical trial registration
Australian and New Zealand Clinical Trials Registry, ACTRN12614000717651. 相似文献52.
Ewelina Kazimierczyk Andrzej Eljaszewicz Paula Zembko Ewa Tarasiuk Malgorzata Rusak Agnieszka Kulczynska-Przybik Marta Lukaszewicz-Zajac Karol Kaminski Barbara Mroczko Maciej Szmitkowski Milena Dabrowska Bozena Sobkowicz Marcin Moniuszko Agnieszka Tycinska 《Pharmacological reports : PR》2019,71(1):73-81
Background
Acute myocardial infarction (AMI) causes irreversible myocardial damage and release of inflammatory mediators, including cytokines, chemokines and miRNAs. We aimed to investigate changes in the levels of cytokines (IL-6, TNF-α and IL-10), miRNAs profiles (miR-146 and miR-155) and distribution of different monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) in the acute and post-healing phases of AMI.Methods
In eighteen consecutive AMI patients (mean age 56.78?±?12.4 years, mean left ventricle ejection fraction – LVEF: 41.9?±?9.8%), treated invasively, monocyte subsets frequencies were evaluated (flow cytometry), cytokine concentrations were analyzed (ELISA) as well as plasma miRNAs were isolated twice – on admission and after 19.2?±?5.9 weeks of follow-up. Measurements were also performed among healthy volunteers.Results
AMI patients presented significantly decreased frequencies of classical cells in comparison to healthy controls (median 71.22% [IQR: 64.4–79.04] vs. 84.35% [IQR: 81.2–86.7], p?=?0.001) and higher percent of both intermediate and non-classical cells, yet without statistical significance (median 6.54% [IQR: 5.14–16.64] vs. 5.87% [IQR: 4.48–8.6], p?=?0.37 and median 5.99% [IQR: 3.39–11.5] vs. 5.26% [IQR: 3.62–6.2], p?=?0.42, respectively). In AMI patients both, analyzed plasma miRNA concentrations were higher than in healthy subjects (miR-146: median 5.48 [IQR: 2.4–11.27] vs. 1.84 [IQR: 0.87–2.53], p?=?0.003; miR-155: median 25.35 [IQR: 8.17–43.15] vs. 8.4 [IQR: 0.08–16.9], p?=?0.027, respectively), and returned back to the values found in the control group in follow-up. miR-155/miR-146 ratio correlated with the frequencies of classical monocytes (r=0.6, p?=?0.01) and miR-155 correlated positively with the concentration of inflammatory cytokines ? IL-6 and TNF-α.Conclusions
These results may suggest cooperation of both pro-inflammatory and anti-inflammatory signals in AMI in order to promote appropriate healing of the infarcted myocardium. 相似文献53.
《Patient education and counseling》2020,103(4):854-863
ObjectiveTo examine the effectiveness of a nurse-led multidisciplinary self-management program (NMSP) on self-management behaviors, self-efficacy, health-related quality of life (HRQoL) and unplanned health service utilization (HSU) among Chinese patients with coronary heart disease (CHD) in communities.MethodsA randomized controlled trial with repeated measurements was used. A convenience sample of 144 participants was recruited from a community health center in China. All participants were randomly assigned to an intervention group (n = 72) in the newly developed NMSP or a control group (n = 72) in routine care. Outcome measurement was performed at baseline, 3 months and 6 months using Coronary Artery Disease Self-Management Scale (CADSs), Self-efficacy for Chronic Disease 6-item Scale (SECD6), and Short Form-12 health survey questionnaire (SF-12).ResultsOver the six months, the two groups reported significant differences in disease medical and emotional management of CADSs, confidence in symptom and disease management of SECD6, physical and mental component summary of SF-12, as well as emergency and outpatient visits of unplanned HSU.ConclusionsThe NMSP improves self-management behaviors, self-efficacy, HRQoL and reduces unplanned HSU among CHD patients in communities.Practice implicationsThis study provides an effective approach to empower CHD patients with emphasizing on collaboration support of health professionals in communities. 相似文献
54.
《JACC: Cardiovascular Interventions》2022,15(12):1205-1215
BackgroundDistal radial access (DRA) has been proposed to improve procedure ergonomics and favor radial artery patency. Although promising data, nothing is known on evolving hand function after DRA.ObjectivesThis study sought to comprehensively evaluate hand function in patients undergoing DRA.MethodsReal-world patients undergoing DRA undertook a thorough multimodality assessment of hand function implementing multidomain questionnaires (Disabilities of the Arm, Shoulder and Hand and Levine-Katz), and motor (pinch grip test) and sensory (Semmes-Weinstein monofilaments test) examinations of both hands. All assessments were performed at preprocedural baseline and planned at 1-, 6-, and 12-month follow-up (FU). Adverse clinical and procedural events were documented too.ResultsData of 313 patients (220 men, age 66 ± 10 years) from 9 international centers were analyzed. The Disabilities of the Arm, Shoulder and Hand and the Levine-Katz scores slightly improved from baseline to FU (P = 0.008 and P = 0.029, respectively). Pinch strength mildly improved from baseline to FU (P < 0.001 for both the left and right hands). Similarly, touch pressure threshold appeared to faintly improve in both the left and right hands (P < 0.012 for all the sites). For both motor and sensory function tests, comparable findings were found for the DRA hand and the contralateral one, with no significant differences between them. Repeated assessment of all tests over all FU time points similarly showed lack of worsening hand function. Access-related adverse events included 19 harmless bleedings and 3 forearm radial artery and 3 distal radial artery occlusions. None affected hand function at FU.ConclusionsIn a systematic multidimensional assessment, DRA was not associated with hand function impairment. Moreover, DRA emerges as a safe alternative vascular access. 相似文献
55.
目的探讨胫前动脉踝上穿支皮瓣修复足踝部软组织缺损的临床疗效。方法回顾性研究2018年4月至2019年6月采用胫前动脉踝上穿支皮瓣修复足踝部软组织缺损19例的资料,其中男11例,女8例;年龄为21~75岁,平均39岁。根据前踝上穿支皮瓣解剖学基础,按照足踝部软组织缺损大小和形状,在小腿下端前外侧设计并切取皮瓣转位修复创面。切取胫前动脉踝上穿支皮瓣面积为6.0 cm×5.0 cm^14.0 cm×8.0 cm,均为带蒂皮瓣转位。根据皮瓣成活、感染控制、弹性色泽、外观形态、供区瘢痕、皮肤感觉、患者认可等情况,对患者足踝部软组织缺损的修复情况进行综合评价。结果本组19例皮瓣全部成活,软组织缺损、肌腱、骨质及钢板外露均得以修复。供区均I期愈合。术后门诊随访2~16个月,皮瓣血运良好,颜色接近周围正常皮肤,臃肿不明显,患者对外观表示满意;供区皮片愈合良好,无明显增生、挛缩及溃疡,踝关节功能良好。结论胫前动脉踝上穿支皮瓣是修复足踝部软组织缺损较为理想的方法之一,手术操作简便,穿支较恒定,血供可靠,具有一定的临床应用价值。 相似文献
56.
目的 通过血清代谢组学技术,考察通阳化浊方与四妙勇安汤在治疗冠心病家兔中的作用机制。方法 40只雄性白兔,随机分为空白组、模型组、通阳化浊方组与四妙勇安汤组4组,每组10只。空白组正常饮食,模型组给予高脂饲料喂养至第8周,于第4周结束后,用球囊法手术损伤实验兔的右侧颈总动脉;在模型组基础上,两个实验组分别在术后,灌胃给予通阳化浊方和四妙勇安汤,连续4周,每日1次。给药结束后,模型组与实验组每组抽取3只家兔,采集全血后,用LC-MS技术进行血清代谢组学检测,运用PCA与OPLS-DA分析法来寻找差异性表达的代谢物和代谢途径。结果 相较于模型组,通阳化浊方与四妙勇安汤组分别存在45和27个差异化合物,通阳化浊方组涉及18条代谢通路,根据Impact值 > 0.05筛选出5条主要代谢通路,包括精氨酸和脯氨酸代谢、组氨酸代谢、牛磺酸和牛磺酸代谢、精氨酸生物合成和α-亚麻酸代谢;四妙勇安汤组涉及11条代谢通路,筛选出2条主要代谢通路分别为牛磺酸和牛磺酸代谢、组氨酸代谢。结论 通阳化浊方与四妙勇安汤在治疗冠心病模型家兔的过程中存在差异性代谢产物,干预相应的代谢通路可能会对药物在模型中的作用产生影响。 相似文献
57.
58.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2022,32(12):2883-2889
Background and aimsCoronary artery disease (CAD) is the principal cause of death in individuals with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to use genetic epidemiology to study the association between de novo lipogenesis (DNL), one of the major pathways leading to NAFLD, and CAD risk.Methods and resultsDNL susceptibility genes were used as instruments and selected using three approaches: 1) genes that are associated with both high serum triglycerides and low sex hormone-binding globulin, both downstream consequences of DNL (unbiased approach), 2) genes that have a known role in DNL (biased approach), and 3) genes that have been associated with serum fatty acids, used as a proxy of DNL. Gene-CAD effect estimates were retrieved from the meta-analysis of CARDIoGRAM and the UK Biobank (~76014 cases and ~264785 controls). Effect estimates were clustered using a fixed-effects meta-analysis. Twenty-two DNL susceptibility genes were identified by the unbiased approach, nine genes by the biased approach and seven genes were associated with plasma fatty acids. Clustering of genes selected in the unbiased and biased approach showed a statistically significant association with CAD (OR:1.016, 95%CI:1.012; 1.020 and OR:1.013, 95%CI:1.007; 1.020, respectively), while clustering of fatty acid genes did not (OR:1.004, 95%CI:0.996–1.011). Subsequent exclusion of potential influential outliers did reveal a statistically significant association (OR:1.009, 95%CI:1.000; 1.018).ConclusionsDNL susceptibility genes are associated with an increased risk of CAD. These findings suggest that DNL may be involved in the pathogenesis of CAD and favor further development of strategies that target NAFLD through DNL. 相似文献
59.
目的 观察SWIM技术治疗后循环大血管闭塞所致急性缺血性卒中的有效性及安全性。
方法 回顾性分析2017年2月-2018年11月于大连市中心医院采用SWIM技术治疗的后循环大血管闭
塞所致急性缺血性卒中患者的临床资料,评价该技术的疗效和安全性,并分析影响患者预后的因素。
观察指标为术后即刻成功再通(mTICI≥2b)、90 d良好预后(mRS评分≤2分),以及术后24 h任何颅内
出血、90 d全因死亡。
结果 共纳入35例患者,平均年龄66.1±12.1岁,男性26例(74.3%),基线NIHSS评分22(15~34)分。
术后即刻成功再通率为94.3%(33/35),90 d良好预后率为45.7%(16/35),24 h颅内出血率为17.1%
(6/35),90 d全因死亡率为37.1%(13/35)。单因素分析显示,基线NIHSS评分较低(P =0.001)、基
线后循环ASPECTS评分较高(P =0.016)、发病至到院时间较短(P =0.039)、发病至再通时间较短
(P =0.047)、血管成功再通率较高(P =0.036)以及饮酒比例较低(P =0.042)与良好预后相关。
结论 使用SWIM技术治疗后循环急性缺血性卒中相对安全、有效。 相似文献
60.
中药(单体/复方)药效物质基础研究是中医药现代研究的关键问题之一。然而,目前运用的生化和分子生物学方法很难诠释其多靶点、整体性和动态性的整合调节作用。课题组提出的"证治代谢组学"假说理论指出,不同的证候存在"证相关代谢谱群"和"证相关生物标志物",这可能是中药药效物质基础所在,辨证论治后偏离的代谢网络功能呈现回归趋势。基于"证治代谢组学"假说开展中药(单体/复方)药效物质基础研究,这将为阐释中药(单体/复方)防病治病和养生保健的科学内涵及其对疾病个体的整合调节作用提供新的思路。本文以冠心病为研究载体、气阴虚血瘀证为切入点、活血保心丸为干预措施,就该研究思路的内涵与总体模式、提出的背景与依据、实践的方式与可行性、创新与特色及其研究意义等进行了简要介绍。 相似文献