全文获取类型
收费全文 | 594篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 8篇 |
妇产科学 | 19篇 |
基础医学 | 86篇 |
口腔科学 | 17篇 |
临床医学 | 50篇 |
内科学 | 86篇 |
皮肤病学 | 6篇 |
神经病学 | 27篇 |
特种医学 | 21篇 |
外科学 | 133篇 |
综合类 | 4篇 |
预防医学 | 41篇 |
眼科学 | 6篇 |
药学 | 42篇 |
肿瘤学 | 68篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 21篇 |
2014年 | 18篇 |
2013年 | 33篇 |
2012年 | 45篇 |
2011年 | 42篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 35篇 |
2007年 | 41篇 |
2006年 | 42篇 |
2005年 | 36篇 |
2004年 | 47篇 |
2003年 | 35篇 |
2002年 | 45篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1962年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有619条查询结果,搜索用时 15 毫秒
11.
Lisa Mosconi Juha O. Rinne Wai H. Tsui John Murray Yi Li Lidia Glodzik Pauline McHugh Schantel Williams Megan Cummings Elizabeth Pirraglia Stanley J. Goldsmith Shankar Vallabhajosula Noora Scheinin Tapio Viljanen Kjell Någren Mony J. de Leon 《Neurobiology of aging》2013
This study examines the relationship between fibrillar beta-amyloid (Aβ) deposition and reduced glucose metabolism, a proxy for neuronal dysfunction, in cognitively normal (NL) individuals with a parent affected by late-onset Alzheimer's disease (AD). Forty-seven 40–80-year-old NL received positron emission tomography (PET) with 11C-Pittsburgh compound B (PiB) and 18F-fluoro-2-deoxy-d-glucose (FDG). These included 19 NL with a maternal history (MH), 12 NL with a paternal history (PH), and 16 NL with negative family history of AD (NH). Automated regions of interest, statistical parametric mapping, voxel-wise intermodality correlations, and logistic regressions were used to examine cerebral-to-cerebellar PiB and FDG standardized uptake value ratios across groups. The MH group showed higher PiB retention and lower metabolism in AD regions compared with NH and PH, which were negatively correlated in posterior cingulate, frontal, and parieto-temporal regions (Pearson r ≤ −0.57, p ≤ 0.05). No correlations were observed in NH and PH. The combination of Aβ deposition and metabolism yielded accuracy ≥ 69% for MH vs. NH and ≥ 71% for MH vs. PH, with relative risk = 1.9–5.1 (p values < 0.005). NL individuals with AD-affected mothers show co-occurring Aβ increases and hypometabolism in AD-vulnerable regions, suggesting an increased risk for AD. 相似文献
12.
Bassem R. Haddad Lei Gu Tuomas Mirtti Ayush Dagvadorj Paraskevi Vogiatzi David T. Hoang Renu Bajaj Benjamin Leiby Elyse Ellsworth Shauna Blackmon Christian Ruiz Mark Curtis Paolo Fortina Adam Ertel Chengbao Liu Hallgeir Rui Tapio Visakorpi Lukas Bubendorf Marja T. Nevalainen 《The American journal of pathology》2013,182(6):2264-2275
13.
Liisa E. Paavola Anne M. Remes Marika J. Harila Tarja T. Varho Tapio T. Korhonen Kari Majamaa 《Journal of Neurodevelopmental Disorders》2015,7(1)
Background
Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.Methods
Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16–65 years, 13 years after a similar examination.Results
The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.Conclusions
Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development. 相似文献14.
15.
Avoranta ST Korkeila EA Syrjänen KJ Pyrhönen SO Sundström JT 《World journal of gastroenterology : WJG》2012,18(33):4549-4556
AIM: To investigate the prognostic value of CD44 variant 6 (CD44v6), a membranous adhesion molecule, in rectal cancer.METHODS: Altogether, 210 rectal cancer samples from 214 patients treated with short-course radiotherapy (RT, n = 90), long-course (chemo) RT (n = 53) or surgery alone (n = 71) were studied with immunohistochemistry for CD44v6. The extent and intensity of membranous and cytoplasmic CD44v6 staining, and the intratumoral membranous staining pattern, were analyzed.RESULTS: Membranous CD44v6 expression was seen in 84% and cytoplasmic expression in 81% of the cases. In 59% of the tumors with membranous CD44v6 expression, the staining pattern in the invasive front was determined as “front-positive” and in 41% as “front-negative”. The latter pattern was associated with narrower circumferential margin (P = 0.01), infiltrative growth pattern (P < 0.001), and shorter disease-free survival in univariate survival analysis (P = 0.022) when compared to the “front-positive” tumors.CONCLUSION: The lack of membranous CD44v6 in the rectal cancer invasive front could be used as a method to identify patients at increased risk for recurrent disease. 相似文献
16.
17.
Jari Tapio Ikonen Antti Ojala Juha-Pekka Salenius Jorma Mattila Heikki Riekkinen Tuija Wigren 《Scandinavian cardiovascular journal : SCJ》2013,47(4):228-233
Although DNA aneuploidy and high proliferative activity (S-phase fraction, SPF) of tumour cells, measured by flow cytometry, have proved to be indicators of poor prognosis in most solid tumours, there have been conflicting results in lung cancer studies. During a four-year period we studied the prognostic significance of DNA ploidy and SPF in 99 surgically treated lung cancer patients. Flow cytometric analysis was done from archival, formalin-fixed, paraffin-embedded tumour specimens. DNA index and SPF were determined, using MultiCycle software with sliced nuclear correction to compensate for debris. There were 61 DNA diploid and 38 DNA aneuploid tumours. The median SPF was 10.2%. Neither ploidy nor SPF was associated with previously known prognostic factors. Survival was poorer in patients with aneuploid tumours than in the other patients, but the difference was not statistically significant. DNA ploidy and SPF thus do not seem to be useful prognostic indicators in surgically treated lung cancer. 相似文献
18.
Heli Koukkunen Karri Penttilä Ari Kemppainen Ilkka Penttilä Matti Halinen Tapio Rantanen Kalevi Pyörälä 《Scandinavian cardiovascular journal : SCJ》2013,47(5):302-306
Objective - To investigate the time window for ruling out myocardial infarction (MI) with troponin T (TnT) and creatine kinase isoenzyme MB mass (CK-MBm) and the prognosis of patients with ruled-out MI diagnosis. Design - The study was based on 397 patients admitted with a suspected acute coronary syndrome but with relief of symptoms within 24 h. Results - MI diagnosis was confirmed with elevated TnT (> 0.10 µg/l) in 108 patients, in 91% within 12-24 h from the onset of symptoms, and in 99% within 12 h from admission. In 94 of these patients CK-MBm became elevated (> 5.0 µg/l), in 95% within 10-12 h from the onset of symptoms, and in 99% within 6 h from admission. Among patients with ruled-out MI diagnosis, the 1-year incidence of recurrent coronary events was 29% in those with positive history of coronary heart disease (CHD) but only 7% in those without prior CHD ( p < 0.001). Conclusion - Using TnT or CK-MBm, MI can be ruled out within 12 h from admission in the majority of patients. Among patients with ruled-out MI diagnosis, positive history of CHD is an important determinant of prognosis. 相似文献
19.
20.
Salla Lahdenpohja Thomas Keller Sarita Forsback Tapio Viljanen Esa Kokkomäki Riikka V. Kivelä Jörgen Bergman Olof Solin Anna K. Kirjavainen 《Journal of labelled compounds & radiopharmaceuticals》2020,63(9):408-418
Here, we describe the development of an in-house-built device for the fully automated multistep synthesis of the cannabinoid CB1 receptor imaging tracer (3R,5R)-5-(3-([18F]fluoromethoxy-d2)phenyl)-3-(((R)-1-phenylethyl)amino)-1-(4-(trifluoromethyl)phenyl)pyrrolidin-2-one ([18F]FMPEP-d2), following good manufacturing practices. The device is interfaced to a HPLC and a sterile filtration unit in a clean room hot cell. The synthesis involves the nucleophilic 18F-fluorination of an alkylating agent and its GC purification, the subsequent 18F-fluoroalkylation of a precursor molecule, the semipreparative HPLC purification of the 18F-fluoroalkylated product, and its formulation for injection. We have optimized the duration and temperature of the 18F-fluoroalkylation reaction and addressed the radiochemical stability of the formulated product. During the past 5 years (2013–2018), we have performed a total of 149 syntheses for clinical use with a 90% success rate. The activity yield of the formulated product has been 1.0 ± 0.4 GBq starting from 11 ± 2 GBq and the molar activity 600 ± 300 GBq/μmol at the end of synthesis. 相似文献