全文获取类型
收费全文 | 1840篇 |
免费 | 258篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 83篇 |
妇产科学 | 32篇 |
基础医学 | 117篇 |
口腔科学 | 76篇 |
临床医学 | 276篇 |
内科学 | 445篇 |
皮肤病学 | 49篇 |
神经病学 | 87篇 |
特种医学 | 295篇 |
外科学 | 140篇 |
综合类 | 19篇 |
预防医学 | 340篇 |
眼科学 | 12篇 |
药学 | 46篇 |
肿瘤学 | 93篇 |
出版年
2023年 | 48篇 |
2022年 | 15篇 |
2021年 | 15篇 |
2020年 | 44篇 |
2019年 | 20篇 |
2018年 | 57篇 |
2017年 | 39篇 |
2016年 | 47篇 |
2015年 | 61篇 |
2014年 | 99篇 |
2013年 | 123篇 |
2012年 | 46篇 |
2011年 | 60篇 |
2010年 | 79篇 |
2009年 | 89篇 |
2008年 | 58篇 |
2007年 | 85篇 |
2006年 | 59篇 |
2005年 | 53篇 |
2004年 | 48篇 |
2003年 | 26篇 |
2002年 | 24篇 |
2001年 | 33篇 |
2000年 | 30篇 |
1999年 | 36篇 |
1998年 | 66篇 |
1997年 | 90篇 |
1996年 | 80篇 |
1995年 | 60篇 |
1994年 | 62篇 |
1993年 | 52篇 |
1992年 | 19篇 |
1991年 | 16篇 |
1990年 | 31篇 |
1989年 | 45篇 |
1988年 | 35篇 |
1987年 | 37篇 |
1986年 | 33篇 |
1985年 | 34篇 |
1984年 | 13篇 |
1983年 | 14篇 |
1982年 | 26篇 |
1981年 | 30篇 |
1980年 | 19篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 14篇 |
1976年 | 14篇 |
1975年 | 10篇 |
1969年 | 2篇 |
排序方式: 共有2119条查询结果,搜索用时 15 毫秒
991.
Neuromedin U (NMU) has been paired with the G-protein-coupled receptors (GPRs) NMU1 (formely designated as the orphan GPR66 or FM-3) and NMU2 (FM-4 or hTGR-1). Recently, a structurally related peptide, neuromedin S (NMS), which shares an amidated C-terminal heptapeptide motif, has been identified in both rat and human, and has been proposed as a second ligand for these receptors. Messenger RNA encoding NMU receptor subtypes shows differential expression: NMU1 is predominantly expressed in peripheral tissues, particularly the gastrointestinal tract, whereas NMU2 is abundant within the brain and spinal cord. NMU peptide parallels receptor distribution with highest expression in the gastrointestinal tract and specific structures within the brain, reflecting its major role in the regulation of energy balance. The NMU knockout mouse has an obese phenotype and, in agreement, the Arg165Trp amino acid variant of NMU-25 in humans, which is functionally inactive, co-segregated with childhood-onset obesity. Emerging physiological roles for NMU include vasoconstriction mediated predominantly via NMU1 with nociception and bone remodelling via NMU2. The NMU system has also been implicated in the pathogenesis of septic shock and cancers including bladder carcinoma and acute myeloid leukaemia. Intriguingly, NMS is more potent at NMU2 receptors in vivo where it has similar central actions in suppression of feeding and regulation of circadian rhythms to NMU. Taken together with its vascular actions, NMU may be a functional link between energy balance and the cardiovascular system and may provide a future target for therapies directed against the disorders that comprise metabolic syndrome. 相似文献
992.
993.
994.
Beaver TA Jansujwicz A Arbuckle BE D'Sa A Palac RT 《Echocardiography (Mount Kisco, N.Y.)》2003,20(4):337-343
OBJECTIVE: To explore the potential advantages of tissue harmonic imaging (THI) versus fundamental frequency imaging (FFI) when applied to tissue characterization. METHODS: A Philips Medical Systems Sonos 5500 echocardiograph equipped with a broadband transducer (S4) and an on-line quantitative analysis software package (Acoustic Densitometry) was used for imaging. The effect of mechanical index (MI), imaging depth, and anisotropy on relative backscatter amplitude was evaluated. RESULTS: This study demonstrated that imaging with tissue harmonics generated relatively greater backscatter values at clinically relevant imaging depths and instrument settings referenced to FFI. This effect was dependent on MI setting. A direct relationship between backscatter amplitude and MI was demonstrated. Additionally, tissue anisotropy had similar effects on integrated backscatter amplitude during both THI and FFI. However, relative backscatter values at each fiber orientation are greater during THI at similar instrument settings when referenced to FFI. CONCLUSION: Tissue harmonic imaging may offer advantages over FFI for myocardial tissue characterization. 相似文献
995.
The panzootic of H5N1 influenza in birds has raised concerns that the virus will mutate to spread more readily in people, leading to a human pandemic. Mathematical models have been used to interpret past pandemics and outbreaks, and to thus model possible future pandemic scenarios and interventions. We review historical influenza outbreak and transmission data, and discuss the way in which modellers have used such sources to inform model structure and assumptions. We suggest that urban attack rates in the 1918–1919 pandemic were constrained by prior immunity, that R0 for influenza is higher than often assumed, and that control of any future pandemic could be difficult in the absence of significant prior immunity. In future, modelling assumptions, parameter estimates and conclusions should be tested against as many relevant data sets as possible. To this end, we encourage researchers to access FluWeb, an on‐line influenza database of historical pandemics and outbreaks. 相似文献
996.
997.
Phase I trial of recombinant human macrophage colony-stimulating factor in patients with invasive fungal infections 总被引:8,自引:1,他引:8
Nemunaitis J; Meyers JD; Buckner CD; Shannon-Dorcy K; Mori M; Shulman H; Bianco JA; Higano CS; Groves E; Storb R 《Blood》1991,78(4):907-913
A phase I dose escalation trial of recombinant human macrophage colony- stimulating factor (rhM-CSF) in combination with conventional antifungal therapy was conducted in 24 marrow transplant recipients with invasive fungal infection. Daily doses ranged from 100 to 2,000 micrograms/m2/d. Toxicity, such as constitutional symptoms, directly ascribed to rhM-CSF was not observed; however, transient, dose-related thrombocytopenia was observed. Patients who received 2,000 micrograms/m2/d of rhM-CSF had a mean reduction in platelet count of 61,000/mm3 during the rhM-CSF infusion period, which was significant when compared with patients who received lower doses of rhM-CSF (P = .008). Fourteen of the 16 patients who received rhM-CSF after undergoing allogeneic bone marrow transplantation had no change in the severity of graft-versus-host disease (GVHD) while receiving rhM-CSF. One had an increase in the severity of GVHD and one had a decrease. There were no effects on neutrophil, monocyte, or lymphocyte counts. Six patients had resolution of their infections, 12 were not evaluable for response, and six did not respond. Ten patients survived 100 days after initiation of rhM-CSF and 14 died. Further trials with rhM-CSF to assess antifungal activity are indicated. 相似文献
998.
999.
1000.
Matthew K. McNabney MD AGSF Ariel R. Green MD MPH PhD Meg Burke MD Stephanie T. Le MD Dawn Butler JD MSW Audrey K. Chun MD David P. Elliott PharmD AGSF BCGP Ana Tuya Fulton MD MBA AGSF Kathryn Hyer PhD MPP Belinda Setters MD MS AGSF Joseph W. Shega MD 《Journal of the American Geriatrics Society》2022,70(7):1960-1972
As people age, they are more likely to have an increasing number of medical diagnoses and medications, as well as healthcare providers who care for those conditions. Health professionals caring for older adults understand that medical issues are not the sole factors in the phenomenon of this “care complexity.” Socioeconomic, cognitive, functional, and organizational factors play a significant role. Care complexity also affects family caregivers, providers, and healthcare systems and therefore society at large. The American Geriatrics Society (AGS) created a work group to review care to identify the most common components of existing healthcare models that address care complexity in older adults. This article, a product of that work group, defines care complexity in older adults, reviews healthcare models and those most common components within them and identifies potential gaps that require attention to reduce the burden of care complexity in older adults. 相似文献