全文获取类型
收费全文 | 1790923篇 |
免费 | 137356篇 |
国内免费 | 12350篇 |
专业分类
耳鼻咽喉 | 22657篇 |
儿科学 | 56514篇 |
妇产科学 | 47248篇 |
基础医学 | 252482篇 |
口腔科学 | 50533篇 |
临床医学 | 164801篇 |
内科学 | 345882篇 |
皮肤病学 | 39744篇 |
神经病学 | 136006篇 |
特种医学 | 67903篇 |
外国民族医学 | 319篇 |
外科学 | 267431篇 |
综合类 | 59030篇 |
现状与发展 | 44篇 |
一般理论 | 536篇 |
预防医学 | 130602篇 |
眼科学 | 43218篇 |
药学 | 134743篇 |
98篇 | |
中国医学 | 11322篇 |
肿瘤学 | 109516篇 |
出版年
2021年 | 16850篇 |
2020年 | 12672篇 |
2019年 | 17427篇 |
2018年 | 23985篇 |
2017年 | 18819篇 |
2016年 | 20043篇 |
2015年 | 24229篇 |
2014年 | 32670篇 |
2013年 | 43567篇 |
2012年 | 60917篇 |
2011年 | 64504篇 |
2010年 | 38514篇 |
2009年 | 35197篇 |
2008年 | 57293篇 |
2007年 | 60505篇 |
2006年 | 60834篇 |
2005年 | 58222篇 |
2004年 | 54357篇 |
2003年 | 51392篇 |
2002年 | 49101篇 |
2001年 | 94027篇 |
2000年 | 95883篇 |
1999年 | 79311篇 |
1998年 | 20652篇 |
1997年 | 18192篇 |
1996年 | 17908篇 |
1995年 | 18071篇 |
1994年 | 16468篇 |
1993年 | 14767篇 |
1992年 | 58181篇 |
1991年 | 55947篇 |
1990年 | 53525篇 |
1989年 | 51265篇 |
1988年 | 46560篇 |
1987年 | 45296篇 |
1986年 | 42520篇 |
1985年 | 40221篇 |
1984年 | 29419篇 |
1983年 | 24929篇 |
1982年 | 13892篇 |
1979年 | 25512篇 |
1978年 | 17528篇 |
1977年 | 14849篇 |
1976年 | 13829篇 |
1975年 | 14513篇 |
1974年 | 17602篇 |
1973年 | 16907篇 |
1972年 | 15664篇 |
1971年 | 14433篇 |
1970年 | 13415篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
José-Luis Andréu María Auxiliadora Martín Héctor Corominas José Javier Pérez-Venegas José Andrés Román-Ivorra Fernando Sánchez-Alonso Ángel Gil de Miguel 《Reumatología clinica》2021,17(4):212-214
IntroductionThe current paradigm of the management of rheumatoid arthritis (RA) recommends achieving a state of remission or low disease activity through the treat-to-target strategy. Our study assesses adherence to this strategy.MethodPatients with RA (ACR-EULAR 2010 criteria) were included. From each centre, 19 patients were randomly selected. Clinical histories (CH) were assessed by independent auditors, checking compliance with predefined quality criteria. The study was approved by ethics committees.ResultsWe included 856 patients (mean age 54 years; 71% women). The use of a combined index (CI) was recorded in 61% of cases. Visits were recorded every 4 weeks using a CI in 4% of CH while attempts were made to achieve remission. Monitoring of disease activity every 6–8 months after reaching the target was recorded in 73% of cases.ConclusionsThe implementation of the treat-to-target strategy is barely recorded in patients with RA in routine clinical practice. 相似文献
74.
Balázs Nemes Réka P. Szabó Dávid Péntek Ildikó Nagy Gergely Ivády Bettina Kárai Eszter Szánthó Zsuzsa Hevessy Sándor Sipka Gergő J. Szőllősi Sándor Baráth 《Transplantation proceedings》2021,53(5):1423-1432
IntroductionThe usage of extended-criteria donors (ECD) became a routinely accepted manner in the last decade. ECD is a potential risk factor for antibody-mediated rejection. Analysis of lymphocyte subsets might be a complementary diagnostic toolkit because there is limited knowledge about this term.MethodBetween May 12, 2016, and September 4, 2019, a total of 130 patients who had undergone kidney transplant were investigated. Patients were divided in ECD and standard criteria donor (SCD) groups. Blood samples were collected before the operation, then in the first week and after 30, 60, 180, and 365 days. Besides routine laboratory tests, multicolor flow cytometry was performed for lymphocyte subsets.ResultsECD grafts were transplanted to older recipients. The number of CD4+ cells increased in the SCDs from the first week to until the end of first month, and then decreased. The number of CD4+ cells decreased from the beginning of the study until the end of first year to 66% of its original value in ECDs. At the first month, the number of CD19+ cells was higher in SCD compared with ECD cases; the number then decreased in both groups. T-regulatory cells had a drop at the first week that lasted until the first month. A bigger increase in SCD and a moderate increase in ECD group were then observed. The kinetics of CD19+ and CD19+ naive cells are similar in the ECD and SCD groups. In the SCD group, cell count decreased in both CD19+ (13%) and CD19+ naive (12%) between third and sixth month. The count of CD19+ cells decreased by 9%, but the count of CD19+ naive cells increased by 11% between the sixth month and first year.DiscussionThe prolonged postoperative uremic state caused by the poorer initial function, together with an aging immune system, explains the weaker immune response in ECD patients, which may be the cause of the decreased number of memory and regulatory T cells. Older patients with an ECD graft need a tailored, personalized, and less aggressive immunosuppressive treatment. 相似文献
75.
76.
77.
J. Ripollés-Melchor C. Aldecoa E. Alday-Muñoz S. del Río A. Batalla E. del-Cojo-Peces R. Uña-Orejón J.L. Muñoz-Rodés J.V. Lorente Á.V. Espinosa C. Ferrando-Ortolà J.L. Jover A. Abad-Gurumeta J.M. Ramírez-Rodríguez A. Abad-Motos 《Revista espa?ola de anestesiología y reanimación》2021,68(7):373-383
BackgroundThe optimal regimen for intravenous administration of intraoperative fluids remains unclear. Our goal was to analyze intraoperative crystalloid volume administration practices and their association with postoperative outcomes.MethodsWe extracted clinical data from two multicenter observational studies including adult patients undergoing colorectal surgery and total hip (THA) and knee arthroplasty (TKA). We analyzed the distribution of intraoperative fluid administration. Regression was performed using a general linear model to determine factors predictive of fluid administration. Patient outcomes and intraoperative crystalloid utilization were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low intraoperative crystalloid with the likelihood of increased postoperative complications, mainly acute kidney injury (AKI) and hospital length of stay (LOS).Results7,580 patients were included. The average adjusted intraoperative crystalloid infusion rate across all surgeries was to 7.9 (SD 4) mL/kg/h. The regression model strongly favored the type of surgery over other patient predictors. We found that high fluid volume was associated with 40% greater odds ratio (OR 1.40; 95% confidence interval1.01-1.95, p = 0.044) of postoperative complications in patients undergoing THA, while we found no associations for the other types of surgeries, AKI and LOSConclusionsA wide variability was observed in intraoperative crystalloid volume administration; however, this did not affect postoperative outcomes. 相似文献
78.
A. Kallifatidis S.-A. Mouratoglou G. Giannakoulas S. Finitsis H. Karvounis G. Sianos 《Diagnostic and interventional imaging》2021,102(3):153-161
PurposeThe purpose of this study was to investigate right atrial and ventricular strain parameters on cardiac magnetic resonance (CMR) in patients with precapillary pulmonary hypertension (PPH) and whether they can aid in the assessment of PPH prognosis.Materials and methodsAdult patients with groups 1 and 4 PPH were invited to participate in the study. Age- and sex-matched healthy volunteers were also recruited as controls. At baseline, patients underwent clinical examination, N-terminal pro-B-type natriuretic peptide measurement and CMR with feature tracking post-processing (CMR-FT). Healthy controls underwent only CMR-FT. The study's primary endpoint was clinical failure, defined as death, hospitalization or demonstrable clinical deterioration during follow-up. Patients who were unable to perform 6-minute walking test due to musculoskeletal disorders were excluded from the study.ResultsThirty-six patients (8 men, 28 women; mean age, 50.6 ± 13.8 [SD] years [range: 18.6–78.5 years]) and 12 healthy control subjects (5 mean, 7 women; mean age, 40.6 ± 13.5 [SD] years [range: 23.1–64.4 years]) were recruited. Right ventricular global longitudinal strain (GLS) was significantly impaired in PPH patients (?20.2 ± 5.3 [SD] % [range: ?28.8 to ?9.1%] vs. ?28.4 ± 3.1% [?33.7 to ?22.7%] respectively, P < 0.001). The right atrial GLS was significantly impaired in PPH compared to healthy controls (?19.9 ± 4.5% [range: ?28.6 to ?3.6%] vs. ?26.5 ± 4.2% [range: ?32.8 to ?15.8%] respectively) (P < 0.001). Clinical failure occurred in 19 (19/36, 53%) of patients. Right ventricular GLS predicted clinical failure most reliably among CMR parameters (?22.6 ± 3.8 [SD] % [range: ?27.6 to ?12.7%] for patients without clinical failure vs. ?18 ± 5.6 [SD] % [range: ?28.8 to ?9.1%] for patients with clinical failure; hazard ratio [HR] = 1.85; P = 0.007; area under the AUC curve = 0.75). Lower absolute right atrial GLS was significantly associated with clinical failure (?22.7 ± 3.0 [SD] % [range: ?28.6 to ?17.7%] for patients without clinical failure vs. ?16.9 ± 5.8 [SD] % [range: ?24.2 to ?3.6%] for patients with clinical failure) (HR = 1.53; P = 0.035).ConclusionCMR feature tracking-derived myocardial strain parameters of both the right atrium and ventricle can assist clinicians in the prognosis of PPH. 相似文献
79.
人工智能(Artificial Intelligence,AI)的蓬勃兴起为现代社会带来了前所未有的机遇,中医药是中华民族传承千年的文化瑰宝。随着人工智能技术不断在中医药领域的科技创新中崭露头角,二者的融合不断加深,人工智能在中医药领域的发展前景、争议挑战也引发了诸多思考。本文将从人工智能在中医药领域的应用入手,对人工智能辅助中医诊断、智能决策与数据挖掘、健康管理及中草药现代化研究等方面,就近年来国内外研究进展进行总结与分析,以期为AI视域下实现中医药现代化、智能化赋能。 相似文献
80.