全文获取类型
收费全文 | 1219篇 |
免费 | 93篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 28篇 |
妇产科学 | 10篇 |
基础医学 | 194篇 |
口腔科学 | 27篇 |
临床医学 | 86篇 |
内科学 | 291篇 |
皮肤病学 | 46篇 |
神经病学 | 150篇 |
特种医学 | 20篇 |
外科学 | 157篇 |
综合类 | 7篇 |
预防医学 | 58篇 |
眼科学 | 5篇 |
药学 | 90篇 |
中国医学 | 1篇 |
肿瘤学 | 149篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 22篇 |
2021年 | 34篇 |
2020年 | 26篇 |
2019年 | 28篇 |
2018年 | 31篇 |
2017年 | 35篇 |
2016年 | 29篇 |
2015年 | 46篇 |
2014年 | 52篇 |
2013年 | 66篇 |
2012年 | 107篇 |
2011年 | 83篇 |
2010年 | 62篇 |
2009年 | 56篇 |
2008年 | 99篇 |
2007年 | 87篇 |
2006年 | 82篇 |
2005年 | 79篇 |
2004年 | 92篇 |
2003年 | 63篇 |
2002年 | 55篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有1321条查询结果,搜索用时 15 毫秒
1.
Massimo Bonacchi Edvin Prifti Massimo Maiani Gabriele Giunti Marzia Leacche 《European journal of cardio-thoracic surgery》2005,28(1):120-126
OBJECTIVE: The aim of this study was to evaluate the feasibility, safety and outcome of skeletonized bilateral internal mammary arteries (BIMA) in patients with unstable angina (UA) undergoing non-elective myocardial revascularization. METHODS: Between January 1997 and December 2003, 758 patients, mean age 62+/-12 years, underwent non-elective coronary artery bypass grafting (CABG) for unstable angina. Two hundred and five (27%) were operated emergently and 503 (73%) urgently. BIMA were employed in 320 (42%) patients (Group B) and isolated left IMA and/or saphenous vein grafts in the remaining 438 (58%) patients (Group M). RESULTS: In-hospital mortality (B = 5.9% and M = 5.3%), and perioperative myocardial infarction (B = 2.2%; M = 1.96%) were similar between the two groups (P = ns). Actuarial survival at 1, 3 and 7 years was 98.7, 97.5 and 96.2% in B and 99, 94.3 and 88.4% in M (P < 0.05 at 7 years follow-up). At 7 years follow-up, the event-free cardiac survival (92 vs. 87%, P = 0.021), angina-free survival (98.6 vs. 94%, P = 0.039), reoperation-free cardiac survival (98 vs. 95%, P = 0.04) and infarct-free cardiac survival (98.7 vs. 96%, P = 0.05) were better in Group B. Multivariate analysis identified age > 65 years (P = 0.02), LVEF < 35% (P = 0.01), > 1 ischemic irreversible area (P = 0.03) as independent predictors for late deaths, while the use of the LIMA (P=0.006) and both mammary arteries (P=0.001) decreased the risk of late deaths. CONCLUSIONS: The use of BIMA in non-elective CABG for UA is safe and effective. Mid-term outcome, however, are superior with improved freedom from cardiac death, from coronary reintervention and from myocardial infarction. 相似文献
2.
Palumbo C Ferretti M Marotti G 《The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology》2004,278(1):474-480
The present ultrastructural investigation into osteocyte dendrogenesis represents a continuation of a previous study (Ferretti et al., Anat. Embryol., 2002; 206:21-29), in which we pointed out that, during intramembranous ossification, the well-known dynamic bone formation (DBF), performed by migrating osteoblast laminae, is preceded by static bone formation (SBF), in which cords of stationary osteoblasts transform into osteocytes in the same site where they differentiated. The research was carried out on the perichondral center of ossification surrounding the mid shaft level of various long bones of chick embryos and newborn rabbits. Transmission electron microscope observations showed that the formation of osteocyte dendrites is quite different in the two types of osteogenesis, mainly depending on whether or not osteoblast movement occurs. In DBF, osteoblasts transform into small ovoidal/ellipsoidal osteocytes and their dendrites form in an asynchronous and asymmetrical manner in concomitance with, and depending on, the advancing mineralizing surface and the receding osteogenic laminae. In SBF, stationary osteoblasts give rise to big globous osteocytes, located inside confluent lacunae, with short and symmetrical dendrites that can radiate simultaneously all around their cell body because they are completely surrounded by unmineralized matrix. Contacts and gap junctions were observed between all osteocytes (both SBF- and DBF-derived) and between osteocytes and osteoblasts. Finally, a continuous osteocyte network extends throughout the bone, regardless of its static or dynamic origin. This network has the characteristic of a functional syncytium, potentially capable of modulating, by wiring transmission, the cells of the osteogenic lineage covering the bone surfaces. 相似文献
3.
Both Human Immunodeficiency Virus Cellular DNA Sequencing and Plasma RNA Sequencing Are Useful for Detection of Drug Resistance Mutations in Blood Samples from Antiretroviral-Drug-Naive Patients 下载免费PDF全文
4.
Clinical,immunological, and molecular analysis in a large cohort of patients with X-linked agammaglobulinemia: an Italian multicenter study 总被引:5,自引:0,他引:5
Plebani A Soresina A Rondelli R Amato GM Azzari C Cardinale F Cazzola G Consolini R De Mattia D Dell'Erba G Duse M Fiorini M Martino S Martire B Masi M Monafo V Moschese V Notarangelo LD Orlandi P Panei P Pession A Pietrogrande MC Pignata C Quinti I Ragno V Rossi P Sciotto A Stabile A;Italian Pediatric Group for XLA-AIEOP 《Clinical immunology (Orlando, Fla.)》2002,104(3):221-230
A questionnaire-based retrospective clinical and immunological survey was conducted in 73 males with a definite diagnosis of X-linked agammaglobulinemia based on BTK sequence analysis. Forty-four were sporadic and 29 familial cases. At December 2000, the patients' ages ranged from 2 to 33 years; mean age at diagnosis and mean duration of follow-up were 3.5 and 10 years respectively. After the mid-1980s all but 2 were on intravenous immunoglobulin (IVIG) substitution therapy, with residual IgG >500 mg/dl in 94% of the patients at the time of enrollment. Respiratory infections were the most frequent manifestation both prior to diagnosis and over follow-up. Chronic lung disease (CLD) was present in 24 patients, in 15 already at diagnosis and in 9 more by 2000. The cumulative risk to present at diagnosis with CLD increased from 0.17 to 0.40 and 0.78 when the diagnosis was made at the ages of 5, 10, and 15 years respectively. For the 9 patients who developed CLD during follow-up, the duration of follow-up, rather than age at diagnosis; previous administration of intramuscular immunoglobulin; and residual IgG levels had a significant effect on the development of CLD. Chronic sinusitis was present in 35 patients (48%), in 15 already at diagnosis and in 20 by 2000. Sistemic infections such as sepsis and meningitis/meningoencephalitis decreased over follow-up, probably due to optimal protection provided by high circulating IgG levels reached with IVIG. 相似文献
5.
Peyvandi F Tagliabue L Menegatti M Karimi M Komáromi I Katona E Muszbek L Mannucci PM 《Human mutation》2004,23(1):98
Factor XIII (FXIII) deficiency is a very rare severe autosomal bleeding disorder with a frequency of 1:2,000,000 in the general population and only a few patients have been genetically characterized so far. We report a phenotype-genotype characterization of 10 unrelated Iranian patients. Two FXIII (transglutaminase) activity assays showed no FXIII activity, except a conserved residual activity in patients receiving prophylactic substitution treatment. FXIII antigen concentrations measured by two immunoassays were comparable. Genotype characterization identified four novel mutations (2 missense and 2 small deletions) and two previously reported missense mutations in the FXIII A subunit gene (F13A). Molecular modeling was carried out to reveal the structural consequences of the missense mutations, that caused the replacement of an arginine residue involved in the formation of structurally important extensive hydrogen-bonded network. The replacements [c.320G>A (p.Arg77His) in the beta-sandwich, c.868C>T (p.Arg260Cys), c.869G>A (p.Arg260His) and c.1236G>T (p.Arg382Ser) in the core domain] resulted in the loss or impairment of such H-bonded network. Energy decomposition analysis demonstrated that this situation leads to the instability and perhaps to the incorrect folding of the A subunit, that would explain the development of severe FXIII deficiency. 相似文献
6.
7.
Chiara Zuccato Marzia Tartari Donato Goffredo Elena Cattaneo Dorotea Rigamonti 《Pharmacological research》2005,52(3):245-251
Treatment of neurodegenerative diseases represents a major challenge for the pharmaceutical industry. Key to developing novel and efficacious therapeutics is the discovery of new druggable targets. Toward this aim, the current drug discovery process is strongly relying on the improved understanding of disease mechanisms and on a synergistic approach with chemistry, molecular biology and robotics. In this scenario, we present the case of a newly discovered molecular mechanism that may be of interest for drug discovery programmes in Huntington's disease and other neurodegenerative diseases. 相似文献
8.
9.
Antonio Leone Marzia Marino Claudia Dell’Atti Viola Zecchi Nicola Magarelli Cesare Colosimo 《Rheumatology international》2016,36(10):1335-1346
The ankylosed spine is prone to fracture even after minor trauma due to its changed biomechanical properties. The two central features of ankylosing spondylitis (AS) that promote the pathological remodeling of the spine are inflammation and new bone formation. AS is also associated with osteoporosis that is attributed to an uncoupling of the bone formation and bone resorption processes. Therefore, bone resorption occurs and promotes weakening of the spine as well as increased risk of vertebral fractures which can be hugely different in terms of clinical relevance. Even in the presence of symptomatic clinical vertebral fractures, the diagnosis can be overruled by attributing the pain to disease activity. Furthermore, given the highly abnormal structure of the spine, vertebral fracture diagnosis can be difficult on the basis of radiography alone. CT can show the fractures in detail. Magnetic resonance imaging is considered the method of choice for the imaging of spinal cord injuries, and a reasonable option for exclusion of occult fractures undetected by CT. Since it is equally important for radiologists and clinicians to have a common knowledge base rather than a compartmentalized view, the aim of this review article was to provide the required clinical knowledge that radiologists need to know and the relevant radiological semiotics that clinicians require in diagnosing clinically significant injury to the ankylosed spine. 相似文献
10.
Progressive aging of the population and prolongation of life expectancy have led to the rising prevalence of heart failure (HF). Despite the improvements in medical therapy, the mortality rate of this condition has remained unacceptably high, becoming the primary cause of death in the elderly population. Almost half of patients with signs and symptoms of HF are found to have a nearly normal ejection fraction, which delineates a distinct clinical syndrome, known as HF with preserved ejection fraction (HF-PEF). While early research focused on the importance of diastolic dysfunction, more recent studies reported the pathophysiological complexity of the disease with multiple cardiovascular abnormalities contributing to its development and progression. HF-PEF is a challenging major health problem with yet no solution as there is no evidence-based treatment which improves clinical outcomes. This review summarizes the state of current knowledge on diagnosis, prognosis and treatment of HF-PEF, with particular insights on the pathological characteristics in the elderly population. 相似文献