全文获取类型
收费全文 | 376篇 |
免费 | 21篇 |
专业分类
儿科学 | 10篇 |
基础医学 | 95篇 |
临床医学 | 22篇 |
内科学 | 153篇 |
皮肤病学 | 1篇 |
神经病学 | 24篇 |
特种医学 | 8篇 |
外科学 | 50篇 |
一般理论 | 1篇 |
预防医学 | 23篇 |
药学 | 3篇 |
肿瘤学 | 7篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 17篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1979年 | 5篇 |
1977年 | 6篇 |
1975年 | 2篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 4篇 |
1967年 | 2篇 |
1934年 | 3篇 |
排序方式: 共有397条查询结果,搜索用时 31 毫秒
1.
2.
Biskup C Kelbauskas L Zimmer T Benndorf K Bergmann A Becker W Ruppersberg JP Stockklausner C Klöcker N 《Journal of biomedical optics》2004,9(4):753-759
Resonance energy transfer (RET) has been extensively used to estimate the distance between two different fluorophores. This study demonstrates how protein-protein interactions can be visualized and quantified in living cells by time-correlated single-photon counting (TCSPC) imaging techniques that exploit the RET between appropriate fluorescent labels. We used this method to investigate the association of the potassium inward rectifier channel Kir2.1 and the neuronal PDZ protein PSD-95, which has been implicated in subcellular targeting and clustering of ion channels. Our data show that the two proteins not only colocalize within clusters but also interact with each other. Moreover, the data allow a spatially resolved quantification of this protein-protein interaction with respect to the relative number and the proximity between interacting molecules. Depending on the subcellular localization, a fraction of 20 to 60% of PSD-95 molecules interacted with Kir2.1 channels, approximating their fluorescent labels by less than 5 nm. 相似文献
3.
4.
HLA associations in insulin-dependent diabetes: search for heterogeneity in different groups of patients from a homogeneous population 总被引:3,自引:0,他引:3
A. Svejgaard B. K. Jakobsen P. Platz L. P. Ryder J. Nerup M. Christy K. Borch-Johnsen H.-H. Parving T. Deckert L. Mølsted-Pedersen C. Kühl K. Buschard A. Green 《Tissue antigens》1986,28(4):237-244
A total of 317 unrelated Danish patients with insulin-dependent diabetes mellitus (IDDM) have been HLA-DR typed and the antigen and phenotype frequencies compared with those in 1177 unrelated Danish controls. The strong positive associations with DR3 and 4 and the strong negative one with DR2 were confirmed, and the remaining antigens showed a hierarchy from weakly positive to strongly negative associations: DRw9, w8, 1, 5, w6, 7. The study population included various special groups of patients selected in order to study heterogeneity: very early (less than 5 years) and very late (greater than 40 years) onset IDDM, pregnancy-induced IDDM, IDDM nephropathy, and long-term (greater than 40 years) survivors without complications. When comparing these groups, the following minor differences were seen: the DR3,4 phenotype is significantly (p = .02) more frequent in IDDM with onset before age 20 (35%) than in other cases (24%), and in familial IDDM (48%) than in other cases (28%); the frequency of the DR4 antigen was significantly (p = .008) more frequent in long-term survivors (86%) than in other patients (69%), while it was significantly (p = .02) less frequent in IDDM nephropathy (63%) than in long-term survivors. However, apart from the age-at-onset heterogeneity, which was suspected a priori, these differences may be due to chance, and the main conclusion of this study is that the HLA-DR associations in IDDM are indeed extraordinarily homogeneous irrespective of the clinical characteristics at onset and course of the disease. 相似文献
5.
Onset of type 1 diabetes: a dynamical instability. 总被引:11,自引:0,他引:11
6.
Christian Johann Lerche M.D. Ketil Jørgen Haugan M.D. Ph.D. Jesper Irving Reimers M.D. DMSc. Nikolaj Ihlemann M.D. Ph.D. 《Echocardiography (Mount Kisco, N.Y.)》2013,30(7):E188-E191
A 17‐year‐old male with a history of newly implanted mechanical valve at the aortic position, presented with fever, rigors, and painful cutaneous abscesses on his lower extremities and was suspected for infective endocarditis. Transthoracic echocardiography (TTE) showed a vegetation‐like structure following the movement of the mechanical heart valve (MHV), which eventually proved to be a product of degassing microbubbles (MB). 相似文献
7.
Jawad H. Butt Nikolaj Ihlemann Ole De Backer Lars Søndergaard Eva Havers-Borgersen Gunnar H. Gislason Christian Torp-Pedersen Lars Køber Emil L. Fosbøl 《Journal of the American College of Cardiology》2019,73(13):1646-1655
Background
Patients undergoing surgical aortic valve replacement (SAVR) are considered at high risk of infective endocarditis (IE). However, data on the risk of IE following transcatheter aortic valve replacement (TAVR) are sparse and limited by the lack of long-term follow-up as well as a direct comparison with patients undergoing SAVR.Objectives
This study sought to investigate the long-term incidence of IE in patients undergoing TAVR and to compare the long-term risk of IE with patients undergoing isolated SAVR.Methods
In this nationwide observational cohort study, all patients undergoing TAVR and isolated SAVR from January 1, 2008, to December 31, 2016, with no history of IE and alive at discharge were identified using data from Danish nationwide registries.Results
A total of 2,632 patients undergoing TAVR and 3,777 patients undergoing isolated SAVR were identified. During a mean follow-up of 3.6 years, 115 patients (4.4%) with TAVR and 186 patients (4.9%) with SAVR were admitted with IE. The median time from procedure to IE hospitalization was 352 days (25th to 75th percentile: 133 to 778 days) in the TAVR group and 625 days (25th to 75th percentile: 209 to 1,385 days) in the SAVR group. The crude incidence rates of IE were 1.6 (95% confidence interval [CI]: 1.4 to 1.9) and 1.2 (95% CI: 1.0 to 1.4) events per 100 person-years in TAVR and SAVR patients, respectively. The cumulative 1-year risk of IE was 2.3% (95% CI: 1.8% to 2.9%) and 1.8% (95% CI: 1.4% to 2.3%) in TAVR and SAVR patients, respectively. Correspondingly, the cumulative 5-year risk of IE was 5.8% (95% CI: 4.7% to 7.0%) and 5.1% (95% CI: 4.4% to 6.0%), respectively. In multivariable Cox proportional hazard analysis, TAVR was not associated with a statistically significant different risk of IE compared with SAVR (hazard ratio: 1.12; 95% CI: 0.84 to 1.49).Conclusions
The 5-year incidence of IE following TAVR was 5.8% and not significantly different than the incidence following SAVR. 相似文献8.
Summary Due to a short observation period previous studies may have underestimated prevalence and recurrence risk of IDDM in relatives of IDDM patients. To obtain a more exact life-time risk estimate we identified 310 probands, representative of Danish IDDM patients, characterized by current age more than 50 years, age at onset 40 years or less and diabetes duration of more than 30 years. Family data were obtained from 291 probands. Mean observation times (age) (± SD) for siblings (n = 553) and offspring (n=359) were 59.4 ± 16.1 years and 33.8 ± 8.8 years, respectively. Of the probands 73 (25.1%) had at least one first-degree relative with IDDM. Seventeen percent had at least one affected sibling. An increase from 10.4% to 22.4% of having first-degree relatives with IDDM among probands with age at onset below 20 years was observed during the period from proband at age 21 years up to 1 September 1992. Among affected siblings 48% of the second cases were affected more than 10 years after the first affected sibling. Using the life-table method cumulative recurrence risks from time of birth were calculated for siblings up to age 30 years of 6.4% and up to age 60 years of 9.6%. For offspring the risk up to age 34 years was 6.3%. In addition, we present a life-table method evaluating the cumulative recurrence risk from time of onset in the proband, as this is the most relevant when giving genetic counselling. In conclusion, the long-term risks of IDDM in siblings and offspring are high compared to that shown in previous reports.Abbreviations IDDM
insulin-dependent diabetes mellitus
- SE
standard error 相似文献
9.
10.
Embolic protection devices for carotid artery stenting: better results than stenting without protection? 总被引:11,自引:0,他引:11
Ralf Zahn Bernd Mark Nikolaj Niedermaier Uwe Zeymer Peter Limbourg Thomas Ischinger Klaus Haerten Karl Eugen Hauptmann Enz-Rüdiger von Leitner Wolfgang Kasper Ulrich Tebbe Jochen Senges 《European heart journal》2004,25(17):1550-1558
AIMS: Carotid artery stenting (CAS) for carotid artery stenoses has become an alternative to carotid endarterectomy. However, CAS itself can cause cerebral ischaemic events. Embolic protection devices (PD) promise to reduce the incidence of these events. METHODS AND RESULTS: From July 1996 to March 2003, 1483 patients from 26 hospitals were included in the prospective CAS Registry of the ALKK study group. A PD was used in 668 of 1483 patients (45%). The use of a PD has grown rapidly over the years and reached 100% in 2003. Patients treated with a PD had prior carotid artery dilatation more often (3.5% versus 1%, p < 0.001), a prior myocardial infarction (34% versus 27.4%, p = 0.007) and a history of arterial hypertension (89.9% versus 78.6%, p = 0.007) compared to patients treated without a PD. A thrombus was more often visible in patients treated under distal protection (16.5% versus 8%, p < 0.001). The use of a PD led to a 10-min longer intervention (45 min versus 35 min median, p < 0.001). Patients treated with a PD had a lower rate of ipsilateral stroke (1.7% versus 4.1%, p = 0.007) and a lower rate of all non-fatal strokes and all deaths (2.1% versus 4.9%, p = 0.004) during the hospital stay. This was confirmed by multiple logistic regression analysis (adjusted OR = 0.45, 95% CI: 0.23-0.91, p = 0.026). A similar reduction could be found for symptomatic as well as asymptomatic carotid artery stenoses. CONCLUSION: Since 1996 there has been a steady increase in the use of PDs for CAS, with a 100% use in 2003. The use of a PD may lower the rate of ipsilateral strokes during CAS. 相似文献