全文获取类型
| 收费全文 | 3076156篇 |
| 免费 | 256933篇 |
| 国内免费 | 32255篇 |
专业分类
| 耳鼻咽喉 | 42572篇 |
| 儿科学 | 85779篇 |
| 妇产科学 | 72832篇 |
| 基础医学 | 395998篇 |
| 口腔科学 | 85081篇 |
| 临床医学 | 288712篇 |
| 内科学 | 557802篇 |
| 皮肤病学 | 58487篇 |
| 神经病学 | 229586篇 |
| 特种医学 | 122877篇 |
| 外国民族医学 | 940篇 |
| 外科学 | 442262篇 |
| 综合类 | 186416篇 |
| 现状与发展 | 107篇 |
| 一般理论 | 1028篇 |
| 预防医学 | 254632篇 |
| 眼科学 | 67667篇 |
| 药学 | 253578篇 |
| 733篇 | |
| 中国医学 | 53033篇 |
| 肿瘤学 | 165222篇 |
出版年
| 2021年 | 35603篇 |
| 2020年 | 26544篇 |
| 2019年 | 27134篇 |
| 2018年 | 35977篇 |
| 2017年 | 33095篇 |
| 2016年 | 31903篇 |
| 2015年 | 42826篇 |
| 2014年 | 58789篇 |
| 2013年 | 83511篇 |
| 2012年 | 115959篇 |
| 2011年 | 121763篇 |
| 2010年 | 85262篇 |
| 2009年 | 79284篇 |
| 2008年 | 110660篇 |
| 2007年 | 114862篇 |
| 2006年 | 111063篇 |
| 2005年 | 102070篇 |
| 2004年 | 91968篇 |
| 2003年 | 86571篇 |
| 2002年 | 82516篇 |
| 2001年 | 140385篇 |
| 2000年 | 142852篇 |
| 1999年 | 116729篇 |
| 1998年 | 32033篇 |
| 1997年 | 28929篇 |
| 1996年 | 28466篇 |
| 1995年 | 27296篇 |
| 1994年 | 25614篇 |
| 1993年 | 23720篇 |
| 1992年 | 91084篇 |
| 1991年 | 87295篇 |
| 1990年 | 84076篇 |
| 1989年 | 81422篇 |
| 1988年 | 75258篇 |
| 1987年 | 73920篇 |
| 1986年 | 69785篇 |
| 1985年 | 66320篇 |
| 1984年 | 49521篇 |
| 1983年 | 42034篇 |
| 1982年 | 24913篇 |
| 1979年 | 45577篇 |
| 1978年 | 31614篇 |
| 1977年 | 26775篇 |
| 1976年 | 24598篇 |
| 1975年 | 26065篇 |
| 1974年 | 32123篇 |
| 1973年 | 30358篇 |
| 1972年 | 28591篇 |
| 1971年 | 26474篇 |
| 1970年 | 24847篇 |
排序方式： 共有10000条查询结果，搜索用时 0 毫秒
61.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献62.
63.
近年来,蚊虫传播的黄热病在非洲和南美洲地区大面积“再流行”,仅南美洲的巴西在一年时间就发现数千例黄热病确诊病例,黄热病已经在非洲和南美洲地区造成巨大的公共卫生负担。此外,在黄热病非流行国家和地区发现大量输入性病例,使得黄热病有可能在非洲和南美洲以外的地区成为“新发传染病”而在世界更大范围流行。为此,世界卫生组织制定了“消除黄热病流行（EYE）”战略,预计利用10年时间在黄热病流行地区接种13.8亿剂量黄热疫苗,以降低黄热病对国际公共卫生健康的危害。 相似文献
64.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3
Objective
Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.Methods
Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.Results
In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.Conclusions
Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection. 相似文献65.
66.
目的探究肿瘤坏死因子-α(Tumornecrosis factor-α,TNF-α)-308基因对导管相关性脓毒症(Catheter related sepsis,CRS)患者病情的影响,旨在为临床治疗CRS提供科学依据。方法选取2017年7月-2018年10月于浙江大学医学院附属杭州市第一人民医院接受治疗的86例CRS患者为研究对象,按照是否并发多器官功能障碍综合征将患者分为试验组和对照组,对照组共48例,未并发多器官功能障碍综合征,试验组共38例,并发多器官功能障碍综合征,分析两组患者TNF-α-308基因多态性差异,使用多因素Logistic回归分析CRS患者并发多器官功能障碍综合征的危险因素。结果试验组GA基因型频率34.21%、AA基因型频率50.00%、高G等位基因频率18.42%均高于对照组,GG基因型频率52.63%、A等位基因频率28.95%均低于对照组,差异均具有统计学意义(P<0.05);多因素Logistic回归分析结果显示,低GG基因型频率、低G等位基因频率、高GA基因型频率、高AA基因型频率、高A等位基因频率是CRS患者并发多器官功能障碍综合征的危险因素(P<0.05)。结论TNF-α-308基因与CRS患者病情密切相关,GG基因型频率和G等位基因频率降低,GA基因型频率、AA基因型频率、A等位基因频率升高会加重患者的病情,增加多器官功能障碍综合征的发生风险,临床上应该加以重视。 相似文献
67.
68.
69.
70.
多生牙也称额外牙,发生率占恒牙列人群的1%~3%,发生于牙弓腭侧者约占85.2%、牙弓内占13.8%、唇颊侧区占1%[1],发生于上颌前牙区者约占98.24%[2]。本病例2颗多生牙萌出于患者右上颌第二、第三磨牙颊侧。现报告如下。1临床资料患者男,40岁。因"右上颌后牙食物嵌塞"于2013-09-25就诊于南昌大学附属口腔医院。检查:全身一般状况良好,口腔内牙齿咬合关系良 相似文献