全文获取类型
收费全文 | 13765篇 |
免费 | 659篇 |
国内免费 | 225篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 206篇 |
妇产科学 | 198篇 |
基础医学 | 2569篇 |
口腔科学 | 654篇 |
临床医学 | 1199篇 |
内科学 | 1631篇 |
皮肤病学 | 112篇 |
神经病学 | 1022篇 |
特种医学 | 182篇 |
外国民族医学 | 1篇 |
外科学 | 887篇 |
综合类 | 1375篇 |
现状与发展 | 2篇 |
一般理论 | 3篇 |
预防医学 | 1162篇 |
眼科学 | 153篇 |
药学 | 2281篇 |
16篇 | |
中国医学 | 421篇 |
肿瘤学 | 519篇 |
出版年
2023年 | 136篇 |
2022年 | 186篇 |
2021年 | 332篇 |
2020年 | 331篇 |
2019年 | 277篇 |
2018年 | 257篇 |
2017年 | 332篇 |
2016年 | 337篇 |
2015年 | 301篇 |
2014年 | 803篇 |
2013年 | 1129篇 |
2012年 | 1001篇 |
2011年 | 1229篇 |
2010年 | 916篇 |
2009年 | 1158篇 |
2008年 | 1125篇 |
2007年 | 654篇 |
2006年 | 603篇 |
2005年 | 587篇 |
2004年 | 483篇 |
2003年 | 428篇 |
2002年 | 285篇 |
2001年 | 185篇 |
2000年 | 161篇 |
1999年 | 159篇 |
1998年 | 201篇 |
1997年 | 194篇 |
1996年 | 109篇 |
1995年 | 116篇 |
1994年 | 104篇 |
1993年 | 74篇 |
1992年 | 45篇 |
1991年 | 53篇 |
1990年 | 50篇 |
1989年 | 28篇 |
1988年 | 34篇 |
1987年 | 16篇 |
1986年 | 17篇 |
1985年 | 29篇 |
1984年 | 30篇 |
1983年 | 27篇 |
1982年 | 23篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 9篇 |
1974年 | 7篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
This paper investigates if respondents' choice to not consider all characteristics of a multiattribute health service may represent preferences. Over the last decade, an increasing number of studies account for attribute non‐attendance (ANA) when using discrete choice experiments to elicit individuals' preferences. Most studies assume such behaviour is a heuristic and therefore uninformative. This assumption may result in misleading welfare estimates if ANA reflects preferences. This is the first paper to assess if ANA is a heuristic or genuine preference without relying on respondents' self‐stated motivation and the first study to explore this question within a health context. Based on findings from cognitive psychology, we expect that familiar respondents are less likely to use a decision heuristic to simplify choices than unfamiliar respondents. We employ a latent class model of discrete choice experiment data concerned with National Health Service managers' preferences for support services that assist with performance concerns. We present quantitative and qualitative evidence that in our study ANA mostly represents preferences. We also show that wrong assumptions about ANA result in inadequate welfare measures that can result in suboptimal policy advice. Future research should proceed with caution when assuming that ANA is a heuristic. 相似文献
62.
Sabrina Storgaard Sørensen Morten Berg Jensen Kjeld Møller Pedersen Lars Ehlers 《Value in health》2018,21(2):239-247
Objectives
To examine the heterogeneity in cost-effectiveness analyses of patient-tailored complex interventions.Methods
Latent class analysis (LCA) was performed on data from a randomized controlled trial evaluating a patient-tailored case management strategy for patients suffering from chronic obstructive pulmonary disease (COPD). LCA was conducted on detailed process variables representing service variation in the intervention group. Features of the identified latent classes were compared for consistency with baseline demographic, clinical, and economic characteristics for each class. Classes for the control group, corresponding to the identified latent classes for the intervention group, were identified using multinomial logistic regression. Cost-utility analyses were then conducted at the class level, and uncertainty surrounding the point estimates was assessed by probabilistic sensitivity analysis.Results
The LCA identified three distinct classes: the psychologically care class, the extensive COPD care class, and the limited COPD care class. Patient baseline characteristics were in line with the features identified in the LCA. Evaluation of cost-effectiveness revealed highly disparate results, and case management for only the extensive COPD care class appeared cost-effective with an incremental cost-effectiveness ratio of £26,986 per quality-adjusted life-year gained using the threshold value set by the National Institute of Health and Care Excellence.Conclusions
Findings indicate that researchers evaluating patient-tailored complex interventions need to address both supply-side variation and demand-side heterogeneity to link findings with outcome. The article specifically proposes the use of LCA because it is believed to have the potential to enable more appropriate targeting of complex care strategies. 相似文献63.
目的 探讨贝利婴幼儿发育量表-Ⅲ(BSID-Ⅲ)筛查版对早产儿神经发育结局的预测性,为早期筛查发育行为疾病提供有效工具。方法 2016年10月-2017年3月采用前瞻性队列研究设计,选取上海市某妇幼保健院早产儿116例,从出生一直随访至矫正6月龄,根据数据分布特点采用Pearson相关分析进行预测效度的评价。结果 BSID-Ⅲ筛查版产后42 d(矫正)测试结果与6月龄(矫正)神经行为结局无相关性(P均>0.05),而3月龄、6月龄认知和运动能力分别与神经行为发育结局具有一定相关性(P均<0.05)。结论 BSID-Ⅲ简化版对6月龄神经行为结局具有一定预测价值,但仍需进一步延长随访月龄,获得更可靠的结果。 相似文献
64.
The long history of health inequality in New Zealand: occupational class and lifespan in the late 1800s and early 1900s 下载免费PDF全文
Nick Wilson Christine Clement Matt Boyd Andrea Teng Alistair Woodward Tony Blakely 《Australian and New Zealand journal of public health》2018,42(2):175-179
Objective: As relatively little is known about how socioeconomic position might have affected health prior to the Second World War, we aimed to study lifespan by occupational class in two cohorts in New Zealand. Methods: The first study included men on the electoral rolls in Dunedin in the period 1893 to 1902. The second study used an established cohort of male military personnel who were recruited for the First World War. Linear regression was used to estimate lifespan by occupational class. Results: The first study of 259 men on the electoral rolls found no substantive lifespan differences between the high and low occupational class groups. But the second study of 2,406 military personnel found that men in the three highest occupational classes lived 3.5 years longer (95%CI: 0.3–6.8 years) than the three lowest classes (in the multivariable analysis adjusting for age in 1918 and rurality of occupation). Conclusions: We found no significant lifespan differences in one cohort, but a second cohort is the earliest demonstration to our knowledge of substantial differences in mortality by socioeconomic position in this country prior to the 1960s. Implications for public health: This study provides historical context to the long‐term efforts to address health inequalities in society. 相似文献
65.
目的探讨科学有效的合理使用抗菌药物的干预方法,为提高抗菌药物预防性使用的合理率提供参考依据。方法选取2011年1—12月及2016年1—12月出院的Ⅰ类切口手术患者为研究对象,2011年为干预前组,2016年为干预后组。制定干预方案,并监测和比较干预前后两组Ⅰ类切口手术患者抗菌药物预防性使用率及合理率。结果干预前后两组分别监测Ⅰ类切口手术患者1 027、3 820例。2012年1月起对围手术期抗菌药物预防性合理使用采取综合干预措施,干预后抗菌药物预防性使用率Ⅰ类切口手术患者由97.18%(998/1 027)下降至21.23%(811/3 820),"7类"手术患者由96.33%(210/218)下降至1.88%(25/1 330);抗菌药物品种选择合理率由21.14%上升至99.38%;用药时机合理率由76.05%上升至99.01%;疗程合理率由23.95%上升至99.06%;联合用药率由12.73%降低至0;术中追加药物合理率由11.72%上升至95.18%;干预前后两组比较,差异均有统计学意义(均P0.01)。Ⅰ类切口手术患者SSI发病率干预前为0.32%,干预后为0.61%,差异无统计学意义(χ2=0.75,P=0.54)。结论有效的干预使围手术期预防性抗菌药物的使用逐步规范,符合国家相关要求。 相似文献
66.
《Vaccine》2018,36(30):4507-4516
Porcine epidemic diarrhea virus (PEDV) is a member of the Alphacoronaviridae genus within the Coronaviridae family. It is the causative agent of porcine epidemic diarrhea, a disease that can have mortality rates as high as 100% in suckling piglets. PEDV causes severe economic loss, and has been in existence for decades. A panzootic starting in 2010 renewed interest in the development of a universal vaccine toward PEDV. This report details several design changes made to a Hepatitis B virus core antigen (HBcAg)-based recombinant vaccine strategy, and their effect in vivo. Initially, several multi-antigen vaccine candidates were able to elicit antibodies specific to three out of four B-cell epitopes inserted into the chimeric proteins. However, a lack of virus neutralization led to a redesign of the vaccines. The focus of the newly redesigned vaccines was to elicit a strong immune response to the YSNIGVCK amino acid motif from PEDV. Genetically modified new vaccine candidates were able to elicit a strong antibody (Ab) response to the YSNIGVCK epitope, which correlated with an increased ability to neutralize the CO strain of PEDV. Additionally, the location of the inserted PEDV epitopes within the vector protein was shown to affect the immune recognition toward the native HBcAg during vaccination. 相似文献
67.
目的观察松果菊苷(ECH)对人肝癌细胞Hep G2生长和缝隙连接细胞通讯(GJIC)的影响。方法 Alamar Blue法绘制Hep G2细胞生长曲线,并检测ECH的细胞毒作用;划痕标记染料示踪技术(SL/DT)法观察空白对照组、API阳性对照组、AGA阴性对照组和ECH组对GJIC的影响;异硫氰酸荧光素(FITC)间接免疫荧光法观察ECH对缝隙连接蛋白Cx43表达的影响。结果 Hep G2细胞在20 000个/m L的细胞密度Alamar Blue还原率与时间有线性关系。ECH(5、10、20、40和80μM)处理Hep G2细胞24 h,细胞存活率分别为(92.69±3.35)%、(88.33±2.12)%、(80.97±2.50)%、(76.95±1.40)%和(69.09±1.11)%(P0.01)。抑制率最高(80μM浓度下)为30.91%。IC50为467.8μM(368.3μg/m L)。SL/DT显示阳性对照芹黄素和ECH处理24 h后,荧光染料在划痕外4列细胞出现了明显荧光(++++),说明细胞出现染料传输的现象。间接免疫荧光法对Cx43表达进行计分,空白对照组细胞得分为(1.40±0.55)分,ECH组得分为(1.60±0.55)分。结果表明ECH组的Cx43表达增强不明显。结论 ECH对Hep G2细胞有细胞毒作用,同时可增强GJIC功能,但Cx43表达不明显,为ECH抗肿瘤机制提供依据。 相似文献
68.
目的:利用本体的方式实现中医哮喘领域的知识的共建共享及推理。方法:通过对中医文献中"哮喘"相关知识的提取,基于斯坦福大学的七步法构建了"哮喘"的疾病本体,实现了哮喘相关知识的领域建模,建立了部分概念与概念间的关系约束及公理。结果:中医哮喘领域本体构建完成能够实现知识的共享以及简单的推理。共有类120个,实例425个,对象属性18个,其中反向属性6个,数值属性2个,等价类公理1个,子类公理138个,基本实现了对哮喘领域知识的语义化表达。结论:本体的构建在知识的共建、共享及未来知识库的语义检索、数据挖掘中具有一定的参考与应用价值。 相似文献
69.
70.