全文获取类型
收费全文 | 8553篇 |
免费 | 456篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 203篇 |
儿科学 | 205篇 |
妇产科学 | 114篇 |
基础医学 | 943篇 |
口腔科学 | 257篇 |
临床医学 | 690篇 |
内科学 | 2281篇 |
皮肤病学 | 89篇 |
神经病学 | 894篇 |
特种医学 | 374篇 |
外国民族医学 | 4篇 |
外科学 | 1330篇 |
综合类 | 21篇 |
预防医学 | 404篇 |
眼科学 | 86篇 |
药学 | 527篇 |
中国医学 | 15篇 |
肿瘤学 | 654篇 |
出版年
2023年 | 120篇 |
2022年 | 209篇 |
2021年 | 354篇 |
2020年 | 256篇 |
2019年 | 286篇 |
2018年 | 303篇 |
2017年 | 203篇 |
2016年 | 264篇 |
2015年 | 298篇 |
2014年 | 340篇 |
2013年 | 432篇 |
2012年 | 646篇 |
2011年 | 631篇 |
2010年 | 353篇 |
2009年 | 304篇 |
2008年 | 444篇 |
2007年 | 476篇 |
2006年 | 388篇 |
2005年 | 362篇 |
2004年 | 349篇 |
2003年 | 300篇 |
2002年 | 253篇 |
2001年 | 129篇 |
2000年 | 94篇 |
1999年 | 105篇 |
1998年 | 62篇 |
1997年 | 55篇 |
1996年 | 45篇 |
1995年 | 44篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 72篇 |
1991年 | 63篇 |
1990年 | 62篇 |
1989年 | 59篇 |
1988年 | 54篇 |
1987年 | 58篇 |
1986年 | 45篇 |
1985年 | 31篇 |
1984年 | 26篇 |
1983年 | 26篇 |
1982年 | 17篇 |
1981年 | 21篇 |
1979年 | 37篇 |
1978年 | 16篇 |
1975年 | 17篇 |
1974年 | 21篇 |
1973年 | 21篇 |
1971年 | 18篇 |
1968年 | 16篇 |
排序方式: 共有9091条查询结果,搜索用时 15 毫秒
81.
Luca Degli Esposti Valentina Perrone Diego Sangiorgi Margherita Andretta Fausto Bartolini Arturo Cavaliere Andrea Ciaccia Stefania Dell'orco Stefano Grego Sara Salzano Loredana Ubertazzo Adriano Vercellone Davide Gatti Angelo Fassio Ombretta Viapiana Maurizio Rossini Giovanni Adami 《Journal of bone and mineral research》2021,36(11):2177-2183
The determinants of the susceptibility to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection and severe coronavirus disease 2019 (COVID-19) manifestations are yet not fully understood. Amino-bisphosphonates (N-BPs) have anti-inflammatory properties and have been shown to reduce the incidence of lower respiratory infections, cardiovascular events, and cancer. We conducted a population-based retrospective observational cohort study with the primary objective of determining if oral N-BPs treatment can play a role in the susceptibility to development of severe COVID-19. Administrative International Classification of Diseases, Ninth Revision, Clinical ModificationI (ICD-9-CM) and anatomical-therapeutic chemical (ATC) code data, representative of Italian population (9% sample of the overall population), were analyzed. Oral N-BPs (mainly alendronate and risedronate) were included in the analysis, zoledronic acid was excluded because of the low number of patients at risk. Incidence of COVID-19 hospitalization was 12.32 (95% confidence interval [CI], 9.61–15.04) and 11.55 (95% CI, 8.91–14.20), of intensive care unit (ICU) utilization because of COVID-19 was 1.25 (95% CI, 0.38–2.11) and 1.42 (95% CI, 0.49–2.36), and of all-cause death was 4.06 (95% CI, 2.50–5.61) and 3.96 (95% CI, 2.41–5.51) for oral N-BPs users and nonusers, respectively. Sensitivity analyses that excluded patients with prevalent vertebral or hip fragility fractures and without concomitant glucocorticoid treatment yielded similar results. In conclusion, we found that the incidence of COVID-19 hospitalization, intensive care unit (ICU) utilization, and COVID-19 potentially related mortality were similar in N-BPs–treated and nontreated subjects. Similar results were found in N-BPs versus other anti-osteoporotic drugs. We provide real-life data on the safety of oral N-BPs in terms of severe COVID-19 risk on a population-based cohort. Our results do not support the hypothesis that oral N-BPs can prevent COVID-19 infection and/or severe COVID-19; however, they do not seem to increase the risk. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献
82.
83.
Antonio Loforte Mariafrancesca Fiorentino Giacomo Murana Gregorio Gliozzi Giulio Giovanni Cavalli Carlo Mariani Sofia Martin Suarez Davide Pacini 《Transplantation proceedings》2021,53(1):311-317
BackgroundThe occurrence of early graft failure (EGF) after heart transplantation (Htx) often requires a mechanical circulatory support (MCS) therapy. The aims of our study were to identify risk factors of mechanically supported severe EGF and evaluate their impact on both early and late outcomes.MethodsBetween January 2000 and December 2019, 499 consecutive adult patients underwent Htx at our institution. Severe EGF was defined as the need for extracorporeal life support (ECLS) within 24 hours after surgery. All available recipient and donor variables were retrospectively analyzed.ResultsOverall, EGF occurred in 58 (11.6%) patients. Post-Htx peripheral or central ECLS was necessary in 32 (6.4%) cases. Independent predictors of severe EGF were, in the recipient group, preoperative transpulmonary gradient (TPG) >12 mm Hg (odds ratio [OR] 4.1, P = .013), preoperative inotropic score >10 (OR 7.3, P = .0001), and pre-Htx ECLS support (OR 5.2, P = .015), while in the donors, a Eurotransplant donor score ≥17 (OR 8.5, P = .005). The absence of EGF was related with a better survival at 1 year and 5 years (94% and 85%, respectively) compared with EGF requiring ECLS population (36% and 28% at 1 year and 5 years, respectively; P < .001). A five-year conditional survival rate did not differ significantly (85% no EGF vs 83% EGF requiring ECLS).ConclusionBoth donor and recipient factors may influence EGF occurrence. Post-Htx ECLS may impact negatively early; however, patients weaned from ECLS eventually benefit from such a rescue treatment with outcomes comparable with Htx patients who did not suffer EGF. 相似文献
84.
Fausto Biancari Giovanni Mariscalco Magnus Dalén Nicla Settembre Henryk Welp Andrea Perrotti Karsten Wiebe Enrico Leo Antonio Loforte Sidney Chocron Davide Pacini Tatu Juvonen L. Mikael Broman Dario Di Perna Hakeem Yusuff Chris Harvey Nicolas Mongardon Juan P. Maureira Antonio Fiore 《Journal of cardiothoracic and vascular anesthesia》2021,35(7):1999-2006
85.
86.
87.
88.
Chiara Mazziotta Carmen Lanzillotti Marcello Govoni Simonetta Falzoni Maria Letizia Tramarin Elisa Mazzoni Mauro Tognon Fernanda Martini John Charles Rotondo 《Immunology》2023,168(4):671-683
Oncogenic Merkel cell polyomavirus (MCPyV) provokes a widespread and asymptomatic infection in humans. Herein, sera from healthy children and young adults (HC, n = 344) aged 0–20 years old were evaluated for anti-MCPyV immunoglobulin G (IgG) and IgM antibodies employing a recently developed immunoassay. Serum MCPyV IgG data from healthy subjects (HS, n = 510) and elderlies (ES, n = 226), aged 21–65/66–100 years old, from our previous studies, were included. The anti-MCPyV IgG and IgM rates in HC sera were 40.7% and 29.7%, respectively. A lower prevalence of anti-MCPyV IgGs was found in HC aged 0–5 years old (13%) compared to 6–10 (52.3%), 11–15 (60.5%) and 16–20 years old (61.6%) cohorts. Age-stratified HCs exhibited similar anti-MCPyV IgM rates (27.9%–32.9%). Serological profiles indicated that anti-MCPyV IgGs and IgMs had low optical densities (ODs) during the first years of life, while IgM ODs appeared to decrease throughout young adulthood. A lower anti-MCPyV IgGs rate was found in HC (40.7%) than HS (61.8%) and ES (63.7%). Upon the 5-years range age-stratification, a lower anti-MCPyV IgGs rate was found in the younger HC cohort aged 0–5 years old compared to the remaining older HC/HS/ES cohorts (52.3%–72%). The younger HC cohort exhibited the lowest anti-MCPyV IgG ODs than the older cohorts. Low anti-MCPyV IgMs rates and ODs were found in the 21–25 (17.5%) and 26–30 (7.7%) years old cohorts. Our data indicate that, upon an early-in-life seroconversion, the seropositivity for oncogenic MCPyV peaks in late childhood/young adulthood and remains at high prevalence and relatively stable throughout life. 相似文献
89.
Garcia S Bergeret D Martini F Andrac L Horschowski N Choux R Levaut M Charpin C 《International journal of oncology》1997,11(4):849-856
VLA, expression was immunohistochemically investigated in 145 breast carcinomas. Frozen tissue sections were probed with monoclonal anti-VLA, using automated (Ventana ES 320 system) and quantitative (SAMBA 2005 image processor) immunoperoxidase. A positive anti-VLA, immunoreaction was observed in 86 tumors (23.5%) within epithelial cells of carcinomas. The positive surface in tumors varied from 3% to 38% (mean = 13.8%, SD=11.5) and was independent of the tumor size, grade, type and aneuploidy, and of nodal status. VLA(2) was significantly correlated with VCAM (p<0.01), VLA(2) (p<0.01), E cadherin (p=0.025), and CD44 v (p<0.01), and an inverse relationship was observed with Ki67/MIB 1 (p=0.0024) and P-53 (p=0.034). In contrast VLA, expression proved to be independent of Bcl-2, c-erbB-2, cathepsin D, tenascin, CD31, ELAM, RE, RP, PS2 immunohistochemical expression. The results suggest that VLA, expression in tumors is related to the regulation of other adhesion molecules involved in the metastasis process, but the prognostic significance and clinical relevance of VLA, immunodetection in breast carcinomas remain to be demonstrated. 相似文献
90.