全文获取类型
收费全文 | 55648篇 |
免费 | 3849篇 |
国内免费 | 1097篇 |
专业分类
耳鼻咽喉 | 416篇 |
儿科学 | 1833篇 |
妇产科学 | 1455篇 |
基础医学 | 5509篇 |
口腔科学 | 833篇 |
临床医学 | 6517篇 |
内科学 | 8244篇 |
皮肤病学 | 291篇 |
神经病学 | 2038篇 |
特种医学 | 1826篇 |
外国民族医学 | 9篇 |
外科学 | 4309篇 |
综合类 | 8845篇 |
现状与发展 | 1篇 |
预防医学 | 8145篇 |
眼科学 | 317篇 |
药学 | 6006篇 |
106篇 | |
中国医学 | 1944篇 |
肿瘤学 | 1950篇 |
出版年
2024年 | 80篇 |
2023年 | 711篇 |
2022年 | 1265篇 |
2021年 | 2180篇 |
2020年 | 2043篇 |
2019年 | 1770篇 |
2018年 | 1791篇 |
2017年 | 1740篇 |
2016年 | 1876篇 |
2015年 | 1831篇 |
2014年 | 3779篇 |
2013年 | 3822篇 |
2012年 | 3518篇 |
2011年 | 3787篇 |
2010年 | 2856篇 |
2009年 | 2644篇 |
2008年 | 2584篇 |
2007年 | 2698篇 |
2006年 | 2221篇 |
2005年 | 2021篇 |
2004年 | 1712篇 |
2003年 | 1407篇 |
2002年 | 1195篇 |
2001年 | 1056篇 |
2000年 | 927篇 |
1999年 | 887篇 |
1998年 | 707篇 |
1997年 | 723篇 |
1996年 | 661篇 |
1995年 | 588篇 |
1994年 | 590篇 |
1993年 | 444篇 |
1992年 | 460篇 |
1991年 | 415篇 |
1990年 | 357篇 |
1989年 | 345篇 |
1988年 | 298篇 |
1987年 | 250篇 |
1986年 | 239篇 |
1985年 | 277篇 |
1984年 | 247篇 |
1983年 | 153篇 |
1982年 | 215篇 |
1981年 | 177篇 |
1980年 | 158篇 |
1979年 | 147篇 |
1978年 | 115篇 |
1977年 | 117篇 |
1976年 | 105篇 |
1975年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
21.
《Anales de pediatría (Barcelona, Spain : 2003)》2020,92(4):241.e1-241.e11
On 31 December 2019, the Wuhan Municipal Committee of Health and Healthcare (Hubei Province, China) reported that there were 27 cases of pneumonia of unknown origin with symptoms starting on the 8 December. There were 7 serious cases with common exposure in market with shellfish, fish, and live animals, in the city of Wuhan. On 7 January 2020, the Chinese authorities identified that the agent causing the outbreak was a new type of virus of the Coronaviridae family, temporarily called «new coronavirus», 2019-nCoV. On January 30th, 2020, the World Health Organisation (WHO) declared the outbreak an International Emergency. On 11 February 2020 the WHO assigned it the name of SARS-CoV2 and COVID-19 (SARS-CoV2 and COVID-19).The Ministry of Health summoned the Specialties Societies to prepare a clinical protocol for the management of COVID-19. The Spanish Paediatric Association appointed a Working Group of the Societies of Paediatric Infectious Diseases and Paediatric Intensive Care to prepare the present recommendations with the evidence available at the time of preparing them. 相似文献
22.
23.
24.
《Indian heart journal》2022,74(1):7-12
BackgroundThe relationship of atrial fibrillation (AF) with coronary artery disease (CAD) is well established, yet it is often missed. There is evidence of myocardial ischemia on stress imaging in AF patients in the absence of obstructive CAD. In this prospective cohort, we studied the angiographic profiles of non-valvular AF patients.MethodsThe study was a nonrandomized, prospective, single-center observational study of consecutive patients of persistent non-valvular AF. Patients symptomatic for AF despite optimal medical therapy for 3 months were recruited and all underwent coronary angiograms (CAG). Patients with prior history of CAD were excluded.ResultsA total of 70 patients were followed for a mean duration of 12 ± 1.4 months. The mean age of the study group was 66.07 (±11.49) years. Hypertension was the commonest comorbidity seen in 74% patients. Obstructive CAD was present in 32 (46%) patients, non-obstructive (<50% stenosis) CAD in 17 (24%) patients and normal coronaries in 21 (30%) patients. Overall 49 (70%) patients had evidence of CAD. Amongst patients without obstructive CAD, slow flow was seen in 16 (42%) patients. Lower baseline ejection fraction, lower haemoglobin & albumin levels and higher creatinine levels was associated with increased mortality. In patients without obstructive CAD, hospitalizations for fast ventricular rate were significantly increased in those having slow flow on CAG (p = 0.005).ConclusionsMajority (70%) of our patients had evidence of atherosclerotic CAD on CAG. A large proportion of patients without obstructive CAD had slow flow on CAG. 相似文献
25.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2022,32(10):2338-2347
Background and aimsResting heart rate variability (HRV) and maximal fat oxidation (MFO) during exercise are both considered as a noninvasive biomarkers for early detection of cardiovascular risk factors. Thus, this study aimed to analyze the relationship between resting HRV parameters and MFO during exercise, and the intensity of exercise that elicit MFO (Fatmax) in healthy sedentary adults.Methods and resultsA total of 103 healthy young adults (22.2 ± 2.3 years old, 67% female; from the ACTIBATE cohort) and 67 healthy middle-aged adults (53.1 ± 5.0 years old, 52% female; from the FIT-AGEING cohort) were included in this cross-sectional study. HRV was assessed using a Polar RS800CX heart rate monitor, while MFO and Fatmax were determined during a graded exercise treadmill test using indirect calorimetry. No significant associations were observed for healthy young adults (standardized β coefficients ranged from ?0.063 to 0.094, and all P ≥ 0.347) and for middle-aged adults (standardized β coefficients ranged from ?0.234 to 0.090, and all P ≥ 0.056). Nevertheless, only a weak association was observed between one HRV parameter in time-domain (the percentage of R-R intervals that shows a difference higher than 50 ms [pNN50]) and MFO in the cohort of middle-aged adults (β coefficient = ?0.279, and P = 0.033).ConclusionThe results of this study suggest that resting HRV parameters are not associated with MFO and Fatmax during exercise in two independent cohorts of healthy sedentary young and middle-aged adults, respectively. 相似文献
26.
Marginal rate-based analyses are widely used for the analysis of recurrent events in clinical trials. In many areas of application, the events are not instantaneous but rather signal the onset of a symptomatic episode representing a recurrent infection, respiratory exacerbation, or bout of acute depression. In rate-based analyses, it is unclear how to best handle the time during which individuals are experiencing symptoms and hence are not at risk. We derive the limiting value of the Nelson-Aalen estimator and estimators of the regression coefficients under a semiparametric rate-based model in terms of an underlying two-state process. We investigate the impact of the distribution of the episode durations, heterogeneity, and dependence on the asymptotic and finite sample properties of standard estimators. We also consider the impact of these features on power in trials designed to test intervention effects on rate functions. An application to a trial of individuals with herpes simplex virus is given for illustration. 相似文献
27.
28.
目的:探讨二补助育汤对胚胎着床障碍模型小鼠子宫内膜形态及血管生成素-1(Ang-1)mRNA、血管内皮生长因子(VEGF)mRNA的表达和定位的影响。方法:24只ICR雌性小鼠随机分为空白组、模型组、戊酸雌二醇组、二补助育汤组,每组6只,用米非司酮建立胚胎着床障碍动物模型,各组给予相应药物灌胃,妊娠第5天处死小鼠后,检测各组妊娠率、平均着床位点数、子宫内膜Ang-1和VEGF mRNA表达量及其蛋白定位。结果:模型组小鼠平均胚胎着床位点数、Ang-1 mRNA、VEGF mRNA表达量明显低于空白组(均P<0.05);与模型组比较,二补助育汤组平均胚胎着床位点数、Ang-1 mRNA、VEGF mRNA表达量显著提高(均P<0.05)。结论:二补助育汤可提高子宫内膜Ang-1和VEGF蛋白表达量,促进子宫内膜血管生成,从而提高子宫内膜容受性。 相似文献
29.
30.