全文获取类型
收费全文 | 63632篇 |
免费 | 4643篇 |
国内免费 | 1948篇 |
专业分类
耳鼻咽喉 | 192篇 |
儿科学 | 923篇 |
妇产科学 | 389篇 |
基础医学 | 5031篇 |
口腔科学 | 560篇 |
临床医学 | 9385篇 |
内科学 | 21891篇 |
皮肤病学 | 216篇 |
神经病学 | 2688篇 |
特种医学 | 3402篇 |
外国民族医学 | 3篇 |
外科学 | 4750篇 |
综合类 | 10399篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 1954篇 |
眼科学 | 530篇 |
药学 | 4677篇 |
42篇 | |
中国医学 | 2393篇 |
肿瘤学 | 791篇 |
出版年
2024年 | 46篇 |
2023年 | 878篇 |
2022年 | 1196篇 |
2021年 | 2393篇 |
2020年 | 2337篇 |
2019年 | 1968篇 |
2018年 | 2072篇 |
2017年 | 1741篇 |
2016年 | 1760篇 |
2015年 | 1985篇 |
2014年 | 3809篇 |
2013年 | 4115篇 |
2012年 | 3239篇 |
2011年 | 3593篇 |
2010年 | 2958篇 |
2009年 | 2830篇 |
2008年 | 3137篇 |
2007年 | 3337篇 |
2006年 | 2886篇 |
2005年 | 2619篇 |
2004年 | 2257篇 |
2003年 | 1939篇 |
2002年 | 1777篇 |
2001年 | 1681篇 |
2000年 | 1299篇 |
1999年 | 1115篇 |
1998年 | 1118篇 |
1997年 | 1089篇 |
1996年 | 893篇 |
1995年 | 1006篇 |
1994年 | 868篇 |
1993年 | 761篇 |
1992年 | 678篇 |
1991年 | 572篇 |
1990年 | 480篇 |
1989年 | 448篇 |
1988年 | 405篇 |
1987年 | 358篇 |
1986年 | 304篇 |
1985年 | 433篇 |
1984年 | 318篇 |
1983年 | 222篇 |
1982年 | 284篇 |
1981年 | 218篇 |
1980年 | 185篇 |
1979年 | 147篇 |
1978年 | 114篇 |
1977年 | 106篇 |
1976年 | 89篇 |
1975年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):449-459.e4
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making. 相似文献
42.
ObjectiveTo investigate the feasibility of transnasal heated humidified high flow nasal cannula oxygen therapy (HFNC) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with respiratory failure in elderly patients. MethodsA total of 176 elderly patients with AECOPD complicated with respiratory failure who were hospitalized at Peking University Shougang Hospital from December 2016 to January 2022 were enrolled, including 82 patients in an HFNC group and 94 patients in an NPPV group. After treatment, pulse oxygen saturation (SPO2), arterial partial pressure of carbon dioxide (PaCO2), oxygenation index (OI), respiratory rate (RR), heart rate (HR), mean arterial pressure (MAP), comfort score, discharge rate, rate of endotracheal intubation, rate of transfer to intensive care unit (ICU), and mortality were compared between the two groups. The independent sample t-test was used for comparison between the two groups. Statistical data are expressed in percentage or number of cases and the χ2 test was used for their comparisons. ResultsThe SPO2 values at 30 min, 1 h, and 6 h were significantly higher in the HFNC group than in the NPPV group (t=-2.049,-2.618, and -3.314, P=0.043, 0.010, and 0.001, respectively). SPO2 before discharge was significantly lower than that of the NPPV group (t=2.162, P=0.033), but OI at each time point and before discharge had no statistical significance (P>0.05). MAP at 6 h was significantly higher in the HFNC group than in the NPPV group (t=-2.209, P=0.029), but within the normal range. HRs at 2 h and 3 h in the HFNC group were significantly higher than those of the NPPV group (t=-2.199 and -2.336, P=0.030 and 0.021, respectively). There were no significant differences in RR, HR, or MAP between the two groups at other time points and before discharge (P>0.05). There was no significant difference in PaCO2 between the two groups (P>0.05). Comfort score in the HFNC group was significantly higher than that of the NPPV group (t=-46.807, P<0.001). There were no significant differences in discharge rate, ICU transfer rate, endotracheal intubation rate, and mortality between the two groups (P>0.05). ConclusionHFNC is as effective as NPPV in treating elderly patients with AECOPD complicated with type Ⅰ or mild type Ⅱ respiratory failure, and HFNC is more comfortable than NPPV. 相似文献
43.
《The Journal for Nurse Practitioners》2019,15(3):e65-e68
A 76-year-old female patient presented to the emergency department with substernal chest pain and dyspnea symptoms. She reported that the symptoms started 2 days earlier. These symptoms can arise from both cardiac and noncardiac conditions. It is difficult to ascribe chest pain and dyspnea symptoms to a single cause. Recognizing these symptoms is critical for inpatient cardiac and primary care nurse practitioners to choose the correct diagnosis and facilitate more effective treatment planning. 相似文献
44.
45.
46.
47.
Ashok Garg Deepak Agrawal Deepika Mishra Gyarsi Lal Sharma 《Echocardiography (Mount Kisco, N.Y.)》2019,36(7):1421-1422
Raghib syndrome is a rare developmental complex consisting of termination of the left superior vena cava in the left atrium, absence of the coronary sinus, and an atrial septal defect commonly located at the posterior‐inferior angle of the atrial septum. This complex was considered unique to Raghib syndrome; however, cases with a normal atrial septum have been reported where the orifice of the unroofed coronary sinus functions as the inter‐atrial communication. Our patient demonstrated an isolated persistent left superior vena cava draining into the left atrium through unroofed coronary sinus and presence of ostium primum atrial septal defect. 相似文献
48.
Hong Li Ting Ting Wu Pei Chang Liu Xue Song Liu Yan Mu Yang Song Guo Yuan Chen Li Ping Xiao Jiang Feng Huang 《The American journal of emergency medicine》2019,37(7):1301-1306
AimsThis retrospective study aims to analyze and explore the clinical characteristics, risk factors, and in-hospital outcomes - including return of spontaneous circulation (ROSC) and survival to discharge - of hospitalized patients admitted with acute coronary syndrome (ACS) suffering cardiac arrest.MethodsACS patients admitted to three tertiary hospitals in Fujian, China, were evaluated retrospectively from January 1, 2012 to December 30, 2016. Data were collected, based on the Utstein Style, for all cases of attempted resuscitation for IHCA. We analyzed patient characteristics, pre-event variables, event variables, and the main outcomes, including ROSC and survival to discharge, and identified the influencing factors on the outcomes.ResultsThe total number of ACS admissions across the three hospitals during this study period was 21,337. Among these admissions, 320 ACS patients experienced IHCA (incidence: 1.50%); 134 (41.9%) patients experienced ROSC; and 68 (21.2%) survived to discharge. The findings indicated that four factors were associated with ROSC, including age <70 years-old, shockable rhythm, duration of resuscitation (≤15 min and 16–30 min), and PCI. Five factors were associated with survival to discharge, including age <70 years-old, shockable rhythm, the duration of resuscitation (≤15 min and 16–30 min), Killip ≤ II, and CCI ≤ 2.ConclusionYounger age, shockable rhythm, and shorter duration of resuscitation were all factors demonstrated to be a predictor of ROSC and survival to hospital discharge. 相似文献
49.
50.
[目的] 应用数据挖掘技术分析安阿玥教授治疗肛瘘术后创面愈合缓慢的用药规律。[方法] 收集2014年7月—2018年6月安阿玥教授收治的肛瘘术后创面愈合缓慢的病例,以“主症、兼症、舌象、脉象、辨证、治法、方药”为项目构建MySQL数据库,利用Python语言搭建分析系统,统计分析获得安阿玥教授治疗肛瘘术后创面愈合缓慢的辨证用药规律。[结果] 共纳入肛瘘术后创面愈合缓慢病例306例,证候多属阴虚内热、气血不足、脾胃不和、热毒内盛、气虚血瘀证,所用方剂多以增液汤、四物汤、青蒿鳖甲汤、半夏泻心汤等加减化裁,用药次数较多的依次为当归、生地、玄参、生黄芪、马齿苋等。[结论] 肛瘘术后创面愈合缓慢以虚证居多,包括阴虚、血虚、气虚等。临床治疗时重视“和血”的辨证思维。数据挖掘技术结果客观反映了安阿玥教授治疗肛瘘术后创面愈合缓慢的临床思路和经验。 相似文献