全文获取类型
收费全文 | 28257篇 |
免费 | 1915篇 |
国内免费 | 491篇 |
专业分类
耳鼻咽喉 | 137篇 |
儿科学 | 846篇 |
妇产科学 | 474篇 |
基础医学 | 2298篇 |
口腔科学 | 364篇 |
临床医学 | 3301篇 |
内科学 | 6140篇 |
皮肤病学 | 309篇 |
神经病学 | 1157篇 |
特种医学 | 1084篇 |
外国民族医学 | 1篇 |
外科学 | 2848篇 |
综合类 | 3011篇 |
预防医学 | 2620篇 |
眼科学 | 543篇 |
药学 | 3610篇 |
8篇 | |
中国医学 | 812篇 |
肿瘤学 | 1100篇 |
出版年
2023年 | 833篇 |
2022年 | 1113篇 |
2021年 | 1786篇 |
2020年 | 1563篇 |
2019年 | 1753篇 |
2018年 | 1582篇 |
2017年 | 1069篇 |
2016年 | 836篇 |
2015年 | 838篇 |
2014年 | 1955篇 |
2013年 | 1879篇 |
2012年 | 1353篇 |
2011年 | 1496篇 |
2010年 | 1169篇 |
2009年 | 1069篇 |
2008年 | 1194篇 |
2007年 | 1147篇 |
2006年 | 829篇 |
2005年 | 772篇 |
2004年 | 641篇 |
2003年 | 595篇 |
2002年 | 480篇 |
2001年 | 376篇 |
2000年 | 313篇 |
1999年 | 286篇 |
1998年 | 242篇 |
1997年 | 226篇 |
1996年 | 219篇 |
1995年 | 232篇 |
1994年 | 209篇 |
1993年 | 204篇 |
1992年 | 199篇 |
1991年 | 168篇 |
1990年 | 182篇 |
1989年 | 162篇 |
1988年 | 155篇 |
1987年 | 108篇 |
1986年 | 100篇 |
1985年 | 255篇 |
1984年 | 194篇 |
1983年 | 157篇 |
1982年 | 155篇 |
1981年 | 132篇 |
1980年 | 93篇 |
1979年 | 77篇 |
1978年 | 56篇 |
1977年 | 52篇 |
1976年 | 35篇 |
1975年 | 35篇 |
1974年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
目的 探讨纠正低蛋白血症对减少抗结核药物性肝损伤(DILI)发生的作用。方法 2019 年3月~2021 年3 月汕头市中心医院感染病科收治的56例肺结核合并低蛋白血症患者被分为两组,每组28例。给予两组2HRZE/4HR抗结核治疗,另给予观察组输注人血白蛋白纠正低蛋白血症,对照组仅接受抗结核治疗,两组治疗时间均为6个月。使用全自动生化分析仪检测血清白蛋白(ALB)、天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、碱性磷酸酶(ALP)和总胆红素(TBIL)水平,采用化学发光法检测血清总胆汁酸(TBA)水平。在DILI发生时,给予护肝治疗。在治疗结束时,评定临床转归,进行痰培养和肺部CT检查。结果 观察组结核治愈有效率为92.9%,显著高于对照组的71.4%(P<0.05);观察组痰菌转阴率为91.3%,显著高于对照组的(66.7%,P<0.05),肺部病变吸收率为89.3%,显著高于对照组的64.3%(P<0.05);在治疗期间,观察组DILI发生率为25.0%,显著低于对照组的53.6%(P<0.05);在DILI发生时,7例观察组血清ALB水平为(35.2±4.9)g/L,显著高,15例对照组【(29.6±4.9)g/L g/L,P<0.05】,而血清TBIL水平为(33.6±5.2)μmol/L,显著低于对照组【(45.7±16.6)μmol/L,P<0.05】;在护肝治疗后,观察组血清AST、ALT、ALP、TBIL和TBA水平分别为(39.4±9.8)U/L、(35.1±10.8)U/L、(98.6±16.2)U/L、(17.4±4.6)μmol/L和(81.3±13.7)μmol/L,均显著低于对照组【分别为(64.8±9.9)U/L、(78.0±13.8)U/L、(133.7±22.9)U/L、(26.5±6.8)μmol/L和(96.9±16.4)μmol/L,P<0.05】。结论 补充人血白蛋白及时纠正低蛋白血症,对于肺结核合并低蛋白血症患者能够提高结核治愈率,降低药物性肝损害发生率,值得进一步研究。 相似文献
2.
3.
4.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):94-103.e24
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established. 相似文献
5.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):622-629.e2
ObjectiveDeterioration of the native aortic valve function by a late progression of rheumatic disease is not infrequent in patients who underwent rheumatic mitral valve surgery; however, this phenomenon has not been clearly quantified.MethodsA total of 1155 consecutive patients (age 52.0 ± 12.9 years; 807 female) who underwent rheumatic mitral valve surgery without concomitant aortic valve surgery from 1997 to 2015 were enrolled. The primary end point was the composite of progression to severe aortic valve dysfunction or a requirement of subsequent aortic valve replacements during follow-up. To determine the risk factors of the primary outcome, we performed the generalized linear mixed model.ResultsThe baseline severities of aortic valve were none to trivial in 880 patients (76.2%), mild in 256 patients (22.2%), and moderate in 19 patients (1.6%). The latest 1062 echocardiographic assessments (91.9%; median, 81.2 postoperative months; interquartile range, 37.3-132.1 months) demonstrated 26 cases (0.33%/patient-year) meeting the primary end point during follow-up. Cumulative incidence of the primary end point at 10 years was 0.4% ± 0.3% and 7.4% ± 2.5% depending on the presence of mild or greater aortic valve dysfunction at baseline (P < .01). In multivariable analyses, aortic valve peak pressure gradient (odds ratio, 1.14; 95% confidence interval, 1.10-1.20), aortic regurgitation degree (mild over none: odds ratio, 3.26; 95% confidence interval, 1.15-9.23), and time (odds ratio, 1.30; 95% confidence interval 1.19-1.41) were significantly associated with the occurrence of the primary end point.ConclusionsProgression of severe aortic valve dysfunction and the need for aortic valve replacement are uncommon in patients undergoing rheumatic mitral valve surgery. However, such events were relatively common among those with mild or greater aortic valve dysfunction at the time of mitral valve surgery. 相似文献
6.
7.
《Journal of Cardiovascular Computed Tomography》2022,16(4):319-326
BackgroundDiabetes mellitus is a major risk factor for coronary artery disease (CAD) and may provoke structural and functional changes in coronary vasculature. The coronary volume to left ventricular mass (V/M) ratio is a new anatomical parameter capable of revealing a potential physiological imbalance between coronary vasculature and myocardial mass. The aim of this study was to examine the V/M derived from coronary computed tomography angiography (CCTA) in patients with diabetes.MethodsPatients with clinically suspected CAD enrolled in the ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) registry and known diabetic status were included. Coronary artery volume and left ventricular myocardial mass were analyzed from CCTA and the V/M ratio was calculated and compared between patients with and without diabetes.ResultsOf the 3053 patients (age 66 ?± ?10 years; 66% male) with known diabetic status, diabetes was present in 21.9%. Coronary volume was lower in patients with diabetes compared to those without diabetes (2850 ?± ?940 ?mm3 vs. 3040 ?± ?970 ?mm3, p ?< ?0.0001), whereas the myocardial mass was comparable between the 2 groups (122 ?± ?33 ?g vs. 122 ?± ?32 ?g, p ?= ?0.70). The V/M ratio was significantly lower in patients with diabetes (23.9 ?± ?6.8 ?mm3/g vs. 25.7 ?± ?7.5 ?mm3/g, p ?< ?0.0001). Among subjects with obstructive CAD (n ?= ?2191, 24.0% diabetics) and non-obstructive CAD (16.7% diabetics), the V/M ratio was significantly lower in patients with diabetes compared to those without (23.4 ?± ?6.7 ?mm3/g vs. 25.0 ?± ?7.3 ?mm3/g, p ?< ?0.0001 and 25.6 ?± ?6.9 ?mm3/g vs. 27.3 ?± ?7.6 ?mm3/g, respectively, p ?= ?0.006).ConclusionThe V/M ratio was significantly lower in patients with diabetes compared to non-diabetics, even after correcting for obstructive coronary stenosis. The clinical value of the reduced V/M ratio in diabetic patients needs further investigation. 相似文献
8.
目的 探讨中性粒细胞-淋巴细胞计数比率 (NLR)、白蛋白-球蛋白比率(AGR)与食管鳞状细胞癌(ESCC)患者总
生存(OS)期的关系,评估两项指标联合对预测 ESCC 患者预后的应用价值。 方法 本研究回顾性分析了自 2015 年 01 月至
2019 年 12 月间于南通大学附属如皋医院首诊并接受手术治疗的 144 例 ESCC 患者的血常规、血生化检测结果与随访数据。
通过受试者操作特征(ROC)曲线确定 NLR、AGR 的最佳临界值,利用曲线下面积(AUC)评估各指标对 ESCC 患者 OS 期的预
测效能。 通过 Kaplan-Meier 曲线及 Cox 单、多变量回归分析评估两种预测指标的预后价值。 结果 根据期曲线,NLR 与 AGR
预测 ESCC 患者 OS 期的最佳截断值分别为 1. 45 和 1. 48, AUC 值分别为 0. 713 (95%CI = 0. 628 ~ 0. 797)和 0. 673 (95%CI =
0. 584~ 0. 761)。 Kaplan-Meier 曲线展示高 NLR( >1. 45)与低 NLR(≤1. 45)组患者的中位 OS 期分别为 51. 8 个月(95%CI =
36. 2~ 67. 3)和 20. 1 个月(95%CI = 14. 1~ 26. 2),差异有统计学意义(χ
2 = 20. 474, P<0. 001)。 术前低 AGR 值( <1. 48)与 ESCC 患者不良预后显著相关[中位 OS 期:22. 5 个月 (95%CI = 15. 1 ~ 29. 9)比 43. 3 个月 (95%CI = 25. 7 ~ 60. 8)],差异有统计
学意义 (χ
2 = 6. 749, P= 0. 009)。 单、多变量 Cox 分析证实淋巴结转移(HR = 3. 626, 95%CI = 2. 152 ~ 6. 110,P<0. 001)、NLR
(HR= 1. 960, 95%CI = 1. 198~ 3. 207,P= 0. 007)与 AGR (HR= 1. 791, 95%CI = 1. 099 ~ 2. 920,P = 0. 019)是 ESCC 患者的独立
预后因素。 此外,我们发现 NLR 联合 AGR 评分(0 分:NLR≤1. 45 且 AGR≥1. 48;1 分: NLR>1. 45 或 AGR<1. 48;2 分:NLR>
1. 45 且 AGR<1. 48 )能够进一步分层 ESCC 患者的预后,患者评分越高,预后越差。 0 分、1 分与 2 分患者的中位 OS 期分别为
56. 6 个月(95%CI = 40. 2~ 67. 3)、29. 9 个月(95%CI = 20. 1~ 39. 8)和 18. 2 个月(95%CI = 12. 1~ 24. 3),组间差异有统计学意义
(0 分比 1 分: χ
2 = 6. 795, P= 0. 009;0 分比 2 分: χ
2 = 19. 529, P<0. 001;1 分比 2 分: χ
2 = 7. 011, P = 0. 008)。 结论 NLR 与
AGR 是评估 ESCC 患者预后的敏感指标,两者联合可以更有效地识别预后不良患者,进而提供更为详尽的预后分层。 相似文献
9.
《Mayo Clinic proceedings. Mayo Clinic》2022,97(7):1237-1246
ObjectiveTo determine the long-term cardiovascular disease risk of astronauts with spaceflight exposure compared with a well-matched cohort.MethodsNational Aeronautics and Space Administration (NASA) astronauts are selected into their profession based upon education, unique skills, and health and are exposed to cardiovascular disease risk factors during spaceflight. The Cooper Center Longitudinal Study (CCLS) is a generally healthy cohort from a preventive medicine clinic in Dallas, Texas. Using a matched cohort design, astronauts who were selected beginning April 1, 1959, (and each subsequent selection class through 2009) and exposed to spaceflight were matched to CCLS participants who met astronaut selection criteria; 1514 CCLS participants matched to 303 astronauts in a 5-to-1 ratio on sex, date of birth, and age. The outcome of cardiovascular mortality through December 31, 2016, was determined by death certificate or National Death Index.ResultsThere were 11 deaths caused by cardiovascular disease (CVD) among astronauts and 46 among CCLS participants. There was no evidence of increased mortality risk in astronauts (hazard ratio [HR]=1.10; 95% confidence interval [CI], 0.50 to 2.45) with adjustment for baseline cardiovascular covariates. However, the secondary outcome of CVD events showed an increased adjusted risk in astronauts (HR=2.41; 95% CI, 1.26 to 4.63).ConclusionNo increased risk of CVD mortality was observed in astronauts with spaceflight exposure compared with a well-matched cohort, but there was evidence of increased total CVD events. Given that the duration of spaceflight will increase, particularly on missions to Mars, continued surveillance and mitigation of CVD risk is needed to ensure the safety of those who venture into space. 相似文献
10.