全文获取类型
收费全文 | 3988篇 |
免费 | 167篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 77篇 |
妇产科学 | 65篇 |
基础医学 | 468篇 |
口腔科学 | 425篇 |
临床医学 | 259篇 |
内科学 | 1107篇 |
皮肤病学 | 64篇 |
神经病学 | 297篇 |
特种医学 | 97篇 |
外科学 | 533篇 |
综合类 | 22篇 |
预防医学 | 291篇 |
眼科学 | 43篇 |
药学 | 254篇 |
中国医学 | 22篇 |
肿瘤学 | 112篇 |
出版年
2023年 | 35篇 |
2022年 | 94篇 |
2021年 | 176篇 |
2020年 | 82篇 |
2019年 | 126篇 |
2018年 | 167篇 |
2017年 | 96篇 |
2016年 | 112篇 |
2015年 | 148篇 |
2014年 | 174篇 |
2013年 | 215篇 |
2012年 | 326篇 |
2011年 | 342篇 |
2010年 | 188篇 |
2009年 | 140篇 |
2008年 | 232篇 |
2007年 | 239篇 |
2006年 | 218篇 |
2005年 | 172篇 |
2004年 | 155篇 |
2003年 | 150篇 |
2002年 | 109篇 |
2001年 | 48篇 |
2000年 | 37篇 |
1999年 | 51篇 |
1998年 | 22篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1992年 | 11篇 |
1991年 | 22篇 |
1990年 | 16篇 |
1989年 | 22篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 7篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 16篇 |
1975年 | 20篇 |
1974年 | 6篇 |
1972年 | 9篇 |
1970年 | 6篇 |
排序方式: 共有4177条查询结果,搜索用时 15 毫秒
31.
The Use of Hyperbaric Oxygen for the Prevention and Management of Osteoradionecrosis of the Jaw: A Dana‐Farber/Brigham and Women's Cancer Center Multidisciplinary Guideline 下载免费PDF全文
32.
33.
Ftima Ramalhosa Maria Joo Amaral Marco Serdio Rui Caetano Oliveira Paulo Teixeira Maria Augusta Cipriano Jos Guilherme Tralho 《Journal of gastrointestinal oncology.》2022,13(4):1997
BackgroundGallbladder carcinoma (GBC) is an uncommon neoplasm with poor long-term survival. Worldwide the incidence rates vary according to geographic area. The multifactorial aetiology and the rarity of the disease limits the studies to improve outcomes in patients, since the treatment remains mostly surgical. The aim of this study was to identify clinicopathological prognostic factors for survival in patients with GBC submitted to surgery in our institution—a tertiary centre in Portugal. Also, to assess the expression of possible biomarkers (HER2, CD44 and ALDH1) in GBC, as well as the frequency of microsatellite instability (MSI) tumours.MethodsClinicopathological characteristics of 41 consecutive patients that underwent surgical resection for GBC (2008–2019) at our hospital were retrospectively reviewed. Clinicopathological factors were assessed and an immunohistochemical (IHC) analysis was done. Microsatellite stability (MSS) was considered if there was maintenance of nuclear expression of MLH1, MSH2, MSH6 and PMS2. Human epidermal growth factor receptor 2 (HER2) expression was evaluated according to the rules applied for gastric cancer and expression of CD44 and ALH1 was evaluated in order to detect cancer stem cells (CSC). Survival analysis was conducted using Kaplan-Meier and Cox regression was used to find prognostic factors.ResultsIncidence of GBC in our cohort of patients was 0.45%, most commonly affecting females. Median overall survival (OS) was 23 months with a 39.6% 5-year survival rate. Stage > II [hazard ratios (HR) =8.58; P=0.007], lymphovascular invasion (LVI) (HR =4.06; P=0.045) and hepatic resection (HR =0.288; P=0.034) independently influenced survival. HER2 positivity and high expression of CD44 or ADLH1 did not show significant influence in survival (P=0.649, P=0.868 and P=0.914, respectively), although HER2 and ALDH1 positive patients showed a tendency to a shorter OS, compared to negative patients. We found no relation between these biomarkers expression and disease stage. All analysed samples had MSS.ConclusionsGBC patients with a worse prognosis can be identified. The overexpression of HER2 could select patients for targeted therapy and prompt tissue sampling in unresectable patients. 相似文献
34.
Vinícius R. D. Pereira Marco A. M. Bezerra Mauro R. B. P. Gomez Guilherme M. Martins Adilson D. da Silva Kleber T. de Oliveira Rodrigo O. M. A. de Souza Giovanni W. Amarante 《RSC advances》2022,12(46):30120
A concise synthesis of molnupiravir in a one-pot two-step approach starting from uridine is described. Formally, herein, two sets of one-pot two-reaction steps introducing simplicity for purifications and using chemically available reagents are presented. In this context, molnupiravir was obtained in up to 68% overall yield and multigram-scale. In addition, HPLC analysis showed the molnupiravir purity above 99%.Fast, effective and chromatography column-free chemical synthesis of molnupiravir. 相似文献
35.
36.
Berlinck RG Hajdu E da Rocha RM de Oliveira JH Hernández IL Seleghim MH Granato AC de Almeida EV Nuñez CV Muricy G Peixinho S Pessoa C Moraes MO Cavalcanti BC Nascimento GG Thiemann O Silva M Souza AO Silva CL Minarini PR 《Journal of natural products》2004,67(3):510-522
Brazil is blessed with a great biodiversity, which constitutes one of the most important sources of biologically active compounds, even if it has been largely underexplored. As is the case of the Amazon and Atlantic rainforests, the Brazilian marine fauna remains practically unexplored in the search for new biologically active natural products. Considering that marine organisms have been shown to be one of the most promising sources of new bioactive compounds for the treatment of different human diseases, the 8000 km of the Brazilian coastline represents a great potential for finding new pharmacologically active secondary metabolites. This review presents the status of marine natural products chemistry in Brazil, including results reported by different research groups with emphasis on the isolation, structure elucidation, and evaluation of biological activities of natural products isolated from sponges, ascidians, octocorals, and Opistobranch mollusks. A brief overview of the first Brazilian program on the isolation of marine bacteria and fungi, directed toward the production of biologically active compounds, is also discussed. The current multidisciplinary collaborative program under development at the Universidade de S?o Paulo proposes to establish a new paradigm toward the management of the Brazilian marine biodiversity, integrating research on the species diversity, ecology, taxonomy, and biogeography of marine invertebrates and microorganisms. This program also includes a broad screening program of Brazilian marine bioresources, to search for active compounds that may be of interest for the development of new drug leads. 相似文献
37.
Domenica Giannandrea Natalia Platonova Michela Colombo Mara Mazzola Valentina Citro Raffaella Adami Filippo Maltoni Silvia Ancona Vincenza Dolo Ilaria Giusti Andrea Basile Anna Pistocchi Laura Cantone Valentina Bollati Lavinia Casati Elisabetta Calzavara Mauro Turrini Elena Lesma Raffaella Chiaramonte 《Haematologica》2022,107(9):2183
Multiple myeloma (MM) is an incurable hematologic neoplasm, whose poor prognosis is deeply affected by the propensity of tumor cells to localize in the bone marrow (BM) and induce the protumorigenic activity of normal BM cells, leading to events associated with tumor progression, including tumor angiogenesis, osteoclastogenesis, and the spread of osteolytic bone lesions. The interplay between MM cells and the BM niche does not only rely on direct cell-cell interaction, but a crucial role is also played by MM-derived extracellular vesicles (MM-EV). Here, we demonstrated that the oncogenic NOTCH receptors are part of MM-EV cargo and play a key role in EV protumorigenic ability. We used in vitro and in vivo models to investigate the role of EV-derived NOTCH2 in stimulating the protumorigenic behavior of endothelial cells and osteoclast progenitors. Importantly, MM-EV can transfer NOTCH2 between distant cells and increase NOTCH signaling in target cells. MM-EV stimulation increases endothelial cell angiogenic ability and osteoclast differentiation in a NOTCH2-dependent way. Indeed, interfering with NOTCH2 expression in MM cells may decrease the amount of NOTCH2 also in MM-EV and affect their angiogenic and osteoclastogenic potential. Finally, we demonstrated that the pharmacologic blockade of NOTCH activation by γ-secretase inhibitors may hamper the biological effect of EV derived by MM cell lines and by the BM of MM patients. These results provide the first evidence that targeting the NOTCH pathway may be a valid therapeutic strategy to hamper the protumorigenic role of EV in MM as well as other tumors. 相似文献
38.
39.
40.
Drio C. Sobral Filho Pedro L. do Rêgo Aquino Guilherme de Souza Silva Caroline B. Fabro 《Current Cardiology Reviews》2021,17(2):209
Left ventricular noncompaction (LVNC) is a congenital pathology that directly affects the lining walls of myocardial tissue, causing trabeculations with blood filling in the inner wall of the heart, concomitantly with the development of a mesocardial thinning. Although LVNC was described for the first time as long ago as 1984, our understanding of the disease with regard to its genetic pattern, diagnosis, clinical presentation and treatment is still scanty. LVNC can present as an isolated condition or associated with congenital heart disease, genetic syndromes or neuromuscular disease. This suggests that LVNC is not a distinct form of cardiomyopathy, but rather a morphological expression of different diseases. Recognition of the disease is of fundamental importance because its clinical manifestations are variable, ranging from the absence of any symptom to congestive heart failure, lethal arrhythmias and thromboembolic events. The study of this disease has emphasized its genetic aspects, as it may be of sporadic origin or hereditary, in which case it most commonly has an autosomal dominant inheritance or one linked to the X chromosome. Echocardiography is the gold standard for diagnosis, and magnetic resonance imaging may refine the identification of the disease, especially in those patients with non-conclusive echocardiography. This article sets out to review the main characteristics of LVNC and present updates, especially in the genetic pattern, diagnosis and treatment of the disease. 相似文献