全文获取类型
收费全文 | 31207篇 |
免费 | 2163篇 |
国内免费 | 993篇 |
专业分类
耳鼻咽喉 | 231篇 |
儿科学 | 1372篇 |
妇产科学 | 371篇 |
基础医学 | 3578篇 |
口腔科学 | 518篇 |
临床医学 | 2467篇 |
内科学 | 4983篇 |
皮肤病学 | 578篇 |
神经病学 | 1743篇 |
特种医学 | 1154篇 |
外国民族医学 | 9篇 |
外科学 | 4149篇 |
综合类 | 2949篇 |
现状与发展 | 4篇 |
一般理论 | 1篇 |
预防医学 | 2252篇 |
眼科学 | 1287篇 |
药学 | 3266篇 |
18篇 | |
中国医学 | 1008篇 |
肿瘤学 | 2425篇 |
出版年
2023年 | 225篇 |
2022年 | 516篇 |
2021年 | 902篇 |
2020年 | 680篇 |
2019年 | 632篇 |
2018年 | 694篇 |
2017年 | 617篇 |
2016年 | 632篇 |
2015年 | 817篇 |
2014年 | 1162篇 |
2013年 | 1316篇 |
2012年 | 1991篇 |
2011年 | 2051篇 |
2010年 | 1407篇 |
2009年 | 1145篇 |
2008年 | 1624篇 |
2007年 | 1565篇 |
2006年 | 1521篇 |
2005年 | 1453篇 |
2004年 | 1237篇 |
2003年 | 1269篇 |
2002年 | 1129篇 |
2001年 | 945篇 |
2000年 | 882篇 |
1999年 | 775篇 |
1998年 | 360篇 |
1997年 | 324篇 |
1996年 | 267篇 |
1995年 | 261篇 |
1994年 | 221篇 |
1993年 | 199篇 |
1992年 | 426篇 |
1991年 | 436篇 |
1990年 | 390篇 |
1989年 | 413篇 |
1988年 | 314篇 |
1987年 | 322篇 |
1986年 | 258篇 |
1985年 | 287篇 |
1984年 | 240篇 |
1983年 | 224篇 |
1982年 | 132篇 |
1981年 | 122篇 |
1979年 | 194篇 |
1978年 | 131篇 |
1975年 | 139篇 |
1974年 | 149篇 |
1973年 | 142篇 |
1972年 | 125篇 |
1971年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
To examine the knowledge level, behaviors, and psychological status of the Chinese population during the COVID-19 pandemic, and to explore the differences between urban and rural areas.We carried out a cross-sectional survey of the knowledge, behaviors related to COVID-19, and mental health in a probability sample of 3001 community residents in 30 provinces or districts across China from February 16–23, 2020. Convenience sampling and a snowball sampling were adopted. We used General Anxiety Disorder (GAD), the 9-item Patient Health Questionnaire (PHQ-9), and knowledge and behaviors questionnaire of community residents regarding COVID-19 designed by us to investigate the psychological status, disease-related knowledge, and the behavior of Chinese urban and rural residents during the pandemic.The average score of anxiety and depression among urban residents was 9.15 and 11.25, respectively, while the figures in rural areas were 8.69 and 10.57, respectively. There was a statistically significant difference in the levels of anxiety (P < .01) and depression (P < .01). Urban participants reported significantly higher levels of knowledge regarding COVID-19 in all aspects (transmission, prevention measures, symptoms of infection, treatment, and prognosis) (P < .01), compared to their rural counterparts. While a majority of respondents in urban areas obtained knowledge through WeChat, other apps, and the Internet (P < .01), residents in rural areas accessed information through interactions with the community (P < .01). Urban residents fared well in exchanging knowledge about COVID-19 and advising others to take preventive measures (P < .01), but fared poorly in advising people to visit a hospital if they displayed symptoms of the disease, compared to rural residents (P < .01). Regression analysis with behavior showed that being female (OR = 2.106, 95%CI = 1.259–3.522), aged 18 ≤ age < 65 (OR = 4.059, 95%CI = 2.166–7.607), being satisfied with the precautions taken by the community (OR = 2.594, 95%CI = 1.485–4.530), disinfecting public facilities in the community (OR = 2.342, 95%CI = 1.206–4.547), having knowledge of transmission modes (OR = 3.987, 95%CI: 2.039, 7.798), symptoms (OR = 2.045, 95%CI = 1.054–4.003), and outcomes (OR = 2.740, 95%CI = 1.513–4.962) of COVID-19, and not having anxiety symptoms (OR = 2.578, 95%CI = 1.127–5.901) were positively associated with affirmative behavior in urban areas. Being married (OR = 4.960, 95%CI = 2.608–9.434), being satisfied with the precautions taken by the community (OR = 2.484, 95%CI = 1.315–4.691), screening to ensure face mask wearing before entering the community (OR = 8.809, 95%CI = 2.649–19.294), and having knowledge about precautions (OR = 4.886, 95%CI = 2.604–9.167) and outcomes (OR = 2.657, 95%CI = 1.309–5.391) were positively associated with acceptable conduct in rural areas.The status of anxiety and depression among urban residents was more severe compared to those living in rural areas. There was a difference in being positively associated with constructive behaviors between rural and urban areas. 相似文献
6.
7.
8.
Roberto V.P. Ribeiro Mitesh V. Badiwala Danny Ramzy Laura C. Tumiati Vivek Rao 《The Journal of thoracic and cardiovascular surgery》2019,157(2):615-625.e1
Objective
Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation.Methods
Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured.Results
Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001).Conclusions
Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction. 相似文献9.
为研究校友资源在高校大学生创新创业教育发展中情况,采用个案调查方法对校友资源在大学生创新创业教育发展中情况进行调查,调查内容涉及影响大学生创新创业意识、动机、教育培养、校友资源运用等多个方面,调查结果运用SPASS软件进行统计分析,最后从高校校友资源角度对高校大学生创新创业发展提出意见建议,以期为高校校友资源在高校创新创业教育发展中提供借鉴和参考。 相似文献
10.
目的:探讨益胃汤加味对改善原发性干燥综合征(primary sj?rgren's syndrome,pSS)气阴两虚、瘀血阻络证患者疲劳症状及免疫学指标的治疗效果。方法:将116例原发性干燥综合征患者按照随机、对照、单盲法分为治疗组与对照组,每组58例。治疗组给予益胃汤加味方,每日1剂,2次/d;对照组给予硫酸羟氯喹200 mg/次,2次/d,两组均连续治疗24周。比较治疗前后两组患者中医证候疗效、中医疲劳症状积分、疲劳症状视觉模拟评分(visual analogue scale,VAS)以及类风湿因子(rheumatoid factor,RF)与血清免疫球蛋白G(immunoglobulin G,IgG)水平。结果:治疗后治疗组患者中医证候疗效优于对照组(Z=3. 712,P0. 05);治疗组中医疲劳积分与疲劳症状视觉模拟评分改善均优于对照组(P0. 05)。治疗6个月后,治疗组IgG水平较本组治疗前明显下降(P0. 05),与对照组组间比较差异无统计学意义。治疗后两组类风湿因子与本组治疗前比较均无明显下降。治疗组不良反应率1. 75%(1/57),对照组不良反应发生率为25. 49%(13/51)。结论:与硫酸羟氯喹相比,益胃汤加味方治疗pSS,可明显改善患者疲劳及总体症状,两者均可降低血清IgG,益胃汤加味方组疗效较硫酸羟氯喹更明显。两组药物对pSS患者RF水平均无明显影响。长期用药,益胃汤加味方治疗pSS较硫酸羟氯喹更为安全。 相似文献