全文获取类型
收费全文 | 10887篇 |
免费 | 683篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 352篇 |
妇产科学 | 329篇 |
基础医学 | 1513篇 |
口腔科学 | 344篇 |
临床医学 | 1661篇 |
内科学 | 1830篇 |
皮肤病学 | 162篇 |
神经病学 | 967篇 |
特种医学 | 194篇 |
外科学 | 943篇 |
综合类 | 111篇 |
一般理论 | 10篇 |
预防医学 | 1594篇 |
眼科学 | 152篇 |
药学 | 683篇 |
1篇 | |
中国医学 | 20篇 |
肿瘤学 | 659篇 |
出版年
2024年 | 8篇 |
2023年 | 68篇 |
2022年 | 122篇 |
2021年 | 253篇 |
2020年 | 181篇 |
2019年 | 250篇 |
2018年 | 319篇 |
2017年 | 211篇 |
2016年 | 275篇 |
2015年 | 289篇 |
2014年 | 421篇 |
2013年 | 579篇 |
2012年 | 881篇 |
2011年 | 919篇 |
2010年 | 520篇 |
2009年 | 481篇 |
2008年 | 800篇 |
2007年 | 811篇 |
2006年 | 765篇 |
2005年 | 716篇 |
2004年 | 663篇 |
2003年 | 546篇 |
2002年 | 556篇 |
2001年 | 78篇 |
2000年 | 50篇 |
1999年 | 82篇 |
1998年 | 102篇 |
1997年 | 85篇 |
1996年 | 60篇 |
1995年 | 60篇 |
1994年 | 46篇 |
1993年 | 53篇 |
1992年 | 31篇 |
1991年 | 18篇 |
1990年 | 22篇 |
1989年 | 26篇 |
1988年 | 26篇 |
1987年 | 17篇 |
1986年 | 10篇 |
1985年 | 20篇 |
1984年 | 20篇 |
1983年 | 24篇 |
1982年 | 19篇 |
1981年 | 26篇 |
1980年 | 26篇 |
1979年 | 21篇 |
1978年 | 11篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1972年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
OBJECTIVE: To review the natriuretic hormone system and discuss its diagnostic, prognostic, and therapeutic potential in critically ill children. DATA SOURCE: A thorough literature search of MEDLINE was performed using search terms including heart defects, congenital; cardiopulmonary bypass, atrial natriuretic factor; natriuretic peptide, brain; carperitide; nesiritide. Preclinical and clinical investigations and review articles were identified that describe the current understanding of the natriuretic hormone system and its role in the regulation of vascular tone and fluid balance in healthy adults and children and in those with underlying cardiac, pulmonary, and renal disease. RESULTS: A predictable activation of the natriuretic hormone system occurs in children with congenital heart disease and congestive heart failure. Further study is needed to confirm preliminary reports that measurement of natriuretic hormone levels in critically ill children provides diagnostic and prognostic information, as has been demonstrated in adult cardiac populations. Natriuretic hormone infusions provide favorable hemodynamic changes and symptomatic relief when used in adults with decompensated congestive heart failure, and uncontrolled case series suggest that similar benefits may exist in children. The biological activity of the natriuretic hormone system may be decreased following pediatric cardiopulmonary bypass, and additional studies are needed to determine whether natriuretic hormone infusions provide clinical benefit in the postoperative period. Preliminary reports suggest that natriuretic hormone infusions cause physiologic improvements in adults with acute lung injury and asthma but not in those with acute renal failure. CONCLUSIONS: Although important perturbations of the natriuretic hormone system occur in critically ill infants and children, further investigation is needed before the measurement of natriuretic peptides and the use of natriuretic hormone infusions are incorporated into routine practice. 相似文献
92.
93.
Patrícia Pereira Denise Tysca Paulo Oliveira Lucimar Filot da Silva Brum Jaqueline Nascimento Picada Patrícia Ardenghi 《Pharmacological research》2005,52(3):199-203
Rosmarinic acid is a naturally occurring hydroxylated compound. It is present in many plants, for example, it occurs in Artemisia capillaris, Calendulla officinalis, Melissa officinalis, Salvia officinalis and in other several plant families. It also shows a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The aim of the present study was to investigate the effect of the i.p. administration of rosmarinic acid (1, 2, 4 or 8 mg kg(-1)) on elevated plus-maze, step-down inhibitory avoidance and open field task in rats. In addition, we evaluated its genotoxic effect on brain tissue using the comet assay. Rosmarinic acid (2 and 4 mg kg(-1)) increased the number of entries in the open arms, suggesting an anxiolytic-like activity when used in lower doses, without affecting the short-term memory (STM) and long-term memory (LTM) retention on inhibitory avoidance task. Eight milligrams per kilograms of this acid was enough to increase the locomotion and motivation of the animals, but not 1, 2 or 4 mg kg(-1), suggesting that in lower doses, this compound can produce anxiolytic-like effect without exerting locomotor alterations or DNA damage in brain tissue. 相似文献
94.
95.
96.
97.
Kevin X. Liu Eileen M. Duggan Alyaa Al‐Ibraheemi Raja Shaikh Denise M. Adams 《Pediatric blood & cancer》2019,66(1)
Epithelioid hemangioma (EH) is a rare benign vascular tumor that occurs in soft tissues and bone and presents between the third and sixth decades of life. Little is known about the clinical course and outcomes of pediatric EH. We report 11 patients diagnosed with EH at a median age of 14.4 years. One patient treated with interferon and one with sirolimus exhibited partial response for >2 years. Although a benign neoplasm, EH is difficult to manage without standard protocols and portends considerable morbidity. Our findings suggest medical management, particularly sirolimus, may benefit these patients; however, long‐term follow‐up is needed. 相似文献
98.
Tsung‐Chieh Fu Joseph J. Carter James P. Hughes Qinghua Feng Stephen E. Hawes Stephen M. Schwartz Long Fu Xi Taylor Lasof Joshua E. Stern Denise A. Galloway Laura A. Koutsky Rachel L. Winer 《International journal of cancer. Journal international du cancer》2016,139(10):2201-2212
To understand high‐risk (hr) human papillomavirus (HPV) epidemiology in mid‐adulthood, we assessed whether associations between incident detection of hrHPV DNA and recent sexual behavior differed according to whether or not there was serologic evidence of prior infection. From 2011 to 2012, we enrolled 409 women aged 30–50 years into a 6‐month longitudinal study. We collected health and sexual behavior histories, enrollment sera for HPV antibody testing, and monthly self‐collected vaginal swabs for HPV DNA genotyping. Generalized estimating equations logistic regression identified risk factors for type‐specific incident hrHPV DNA, stratified by type‐specific hrHPV serostatus at enrollment. Population attributable risks of hrHPV due to prior and recent exposure were estimated. When type‐specific hrHPV serology was negative, recent sexual risk behavior was positively associated with incident hrHPV DNA (odds ratio in women reporting ≥3 recent sexual risk behaviors [e.g., new or multiple partners] vs. no recent sexual activity = 9.8, 95% CI: 2.4–40.6). No associations with recent sexual behavior were observed with positive type‐specific hrHPV serology. Thirty percent of incident hrHPV DNA detection was attributable to prior infection (with positive serology) and 40% was attributable to recent sexual risk behavior (with negative serology). The proportion of incident hrHPV DNA detection attributable to recent sexual risk behavior decreased with increasing age. Among women with serologic evidence of prior infection, re‐detection of the same hrHPV type is likely due to reactivation or intermittent detection of persistent infection. Without serologic evidence of prior infection, new detection is likely due to new acquisition or to intermittent detection of persisting infection. 相似文献
99.
Femke C.R. Staal Denise J. van der Reijd Marjaneh Taghavi Doenja M.J. Lambregts Regina G.H. Beets-Tan Monique Maas 《Clinical colorectal cancer》2021,20(1):52-71
Prediction of outcome in patients with colorectal cancer (CRC) is challenging as a result of lack of a robust biomarker and heterogeneity between and within tumors. The aim of this review was to assess the current possibilities and limitations of radiomics (on computed tomography [CT], magnetic resonance imaging [MRI], and positron emission tomography [PET]) for the prediction of treatment outcome and long-term outcome in CRC. Medline/PubMed was searched up to August 2020 for studies that used radiomics for the prediction of response to treatment and survival in patients with CRC (based on pretreatment imaging). The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool and Radiomics Quality Score (RQS) were used for quality assessment. A total of 76 studies met the inclusion criteria and were included for further analysis. Radiomics analyses were performed on MRI in 41 studies, on CT in 30 studies, and on 18F-FDG-PET/CT in 10 studies. Heterogeneous results were reported regarding radiomics methods and included features. High-quality studies (n = 13), consisting mainly of MRI-based radiomics to predict response in rectal cancer, were able to predict response with good performance. Radiomics literature in CRC is highly heterogeneous, but it nonetheless holds promise for the prediction of outcome. The most evidence is available for MRI-based radiomics in rectal cancer. Future radiomics research in CRC should focus on independent validation of existing models rather than on developing new models. 相似文献
100.
Consumption of vegetables and fruits and risk of subtypes of head–neck cancer in the Netherlands Cohort Study 下载免费PDF全文
Denise H.E. Maasland Piet A. van den Brandt Bernd Kremer R. Alexandra Goldbohm Leo J. Schouten 《International journal of cancer. Journal international du cancer》2015,136(5):E396-E409
There is limited prospective data on the relationship between consumption of vegetables and fruits and the risk of head–neck cancer (HNC) subtypes [i.e., oral cavity cancer (OCC), oro‐/hypopharyngeal cancer (OHPC) and laryngeal cancer (LC)]. Therefore, we investigated these associations within the Netherlands Cohort Study, in which 120,852 participants completed a 150‐item food frequency questionnaire at baseline in 1986. After 20.3 years of follow‐up, 415 cases of HNC (131 OCC, 88 OHPC, three oral cavity/pharynx unspecified or overlapping and 193 LC) and 3,898 subcohort members were available for case–cohort analysis using Cox proportional hazards models. Total vegetable and fruit consumption was inversely associated with risk of HNC overall [multivariable‐adjusted rate ratios for highest vs. lowest quartile: 0.61, 95% confidence interval (CI) 0.44–0.85, p trend 0.002] and all HNC subtypes, with the strongest associations for OCC. Total vegetable intake and total fruit intake were also associated with a decreased risk of HNC overall and HNC subtypes. No significant interaction was found between vegetable and fruit intake and alcohol consumption or cigarette smoking. In conclusion, in this large‐scale cohort study, consumption of vegetables and fruits was associated with a decreased risk of HNC overall and all subtypes. Consumption of vegetables and fruits (or of specific groups of them) may protect against HNC and its subtypes. 相似文献