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排序方式: 共有2889条查询结果,搜索用时 15 毫秒
71.
Patient‐specific pharmacokinetic parameter estimation on dynamic contrast‐enhanced MRI of prostate: Preliminary evaluation of a novel AIF‐free estimation method 下载免费PDF全文
72.
Bravin A Keyriläinen J Fernández M Fiedler S Nemoz C Karjalainen-Lindsberg ML Tenhunen M Virkkunen P Leidenius M von Smitten K Sipilä P Suortti P 《Physics in medicine and biology》2007,52(8):2197-2211
The aim of this study was to introduce high-resolution computed tomography (CT) of breast tumours using the diffraction-enhanced x-ray imaging (DEI) technique and to compare results with radiological and histo-pathological examinations. X-ray CT images of tumour-bearing breast tissue samples were acquired by monochromatic synchrotron radiation (SR). Due to the narrow beam and a large sample-to-detector distance scattering is rejected in the absorption contrast images (SR-CT). Large contrast enhancement is achieved by the use of the DEI-CT method, where the effects of refraction and scatter rejection are analysed by crystal optics. Clinical mammograms and CT images were recorded as reference material for a radiological examination. Three malignant and benign samples were studied in detail. Their radiographs were compared with optical images of stained histological sections. The DEI-CT images map accurately the morphology of the samples, including collagen strands and micro-calcifications of dimensions less than 0.1 mm. Histo-pathological examination and reading of the radiographs were done independently, and the conclusions were in general agreement. High-resolution DEI-CT images show strong contrast and permit visualization of details invisible in clinical radiographs. The radiation dose may be reduced by an order of magnitude without compromising image quality, which would make possible clinical in vivo DEI-CT with future compact SR sources. 相似文献
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Jani Rankinen Petri Haataja LeoPekka Lyytikinen Heini Huhtala Terho Lehtimki Mika Khnen Markku Eskola Andrs Ricardo PrezRiera Antti Jula Harri Rissanen Kjell Nikus Jussi Hernesniemi 《Annals of noninvasive electrocardiology》2021,26(1)
BackgroundPrevious population studies have presented conflicting results regarding the prognostic impact of intraventricular conduction delays (IVCD).MethodsWe studied long‐term prognostic impact and the association with comorbidities of eight IVCDs in a random sample of 6,299 Finnish subjects (2,857 men and 3,442 women, mean age 52.8, SD 14.9 years) aged 30 or over who participated in the health examination including 12‐lead ECG. For left bundle branch block (LBBB) and non‐specific IVCD (NSIVCD), two different definitions were used.ResultsDuring 16.5 years’ follow‐up, 1,309 of the 6,299 subjects (20.8%) died and of these 655 (10.4%) were cardiovascular (CV) deaths. After controlling for known clinical risk factors, the hazard ratio for CV death, compared with individuals without IVCD, was 1.55 for the Minnesota definition of LBBB (95% confidence interval 1.04–2.31, p = .032) and 1.27 (95% confidence interval 0.80–2.02, p = .308) for the Strauss’ definition of LBBB. Subjects with NSIVCD were associated with twofold to threefold increase in CV mortality depending on the definition. While right bundle branch block, left anterior fascicular block and incomplete bundle branch blocks were associated with seemingly higher mortality, this was no longer the case after adjustment for age and sex. The presence of R‐R’ pattern was not associated with any adverse outcome.ConclusionsIn a population study with long‐term follow‐up, NSIVCD and Minnesota definition of LBBB were independently associated with CV mortality. Other IVCDs had no significant impact on prognosis. The prognostic impact of LBBB and NSIVCD was affected by the definition of the conduction disorder. 相似文献
75.
Maria Francesca Sfondrini Simone Gallo Benedetta Turcato Mona A. Montasser Nehal Fouad Albelasy Pekka K. Vallittu Paola Gandini Andrea Scribante 《Materials》2021,14(6)
This study aims to assess the efficacy of a universal adhesive (Scotchbond Universal, 3M ESPE) (SB) in total-etch mode, compared to a traditional orthodontic primer (Transbond XT Primer, 3M ESPE) (XT Primer), to perform bonding of orthodontic fixed retainers along with the Transbond XT Light Cure Adhesive Paste (3M ESPE). For the in vitro study, a round section wire (Ortosmail Krugg) was bonded using XT Primer for 20 bovine incisors (Group 1) and SB for other 20 (Group 2). Samples were debonded in a universal testing machine applying a tangential force to specimens (crosshead speed of 1 millimeter per minute). Shear bond strength (SBS) and adhesive remnant index (ARI) scores were calculated. For the in vivo study, 100 patients needing upper and lower canine-to-canine fixed retainers after orthodontic treatment were randomly assigned to two groups of 50 participants each, i.e., group 1 (retainer bonding with XT Primer) and group 2 (retainer bonding with SB). Over two years, examinations were carried out monthly, and detachments were registered by considering the teeth and arches affected. In vitro, no statistically significant differences in SBS and ARI scores were demonstrated between the two groups, both showing a mean bond strength of about 12 MPa and major frequency of ARI “2” (>50% remnant adhesive on the enamel). Conversely, a significantly lower failure rate over 2 years was assessed clinically for group 2 in both arches. Independently of the adhesive and arch, incisors reported a significantly higher failure rate than canines. Scotchbond Universal used in total-etch mode could be a valid alternative to the traditional orthodontic Transbond XT Primer. 相似文献
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This article reviews the use of conventional disease-modifying antirheumatic drugs (DMARDs) in the treatment of early rheumatoid arthritis (RA). The Finnish early RA cohorts are used as examples of how early and active treatment strategies have improved over time with increasing variety of available DMARDs. Therapy goals of early RA include remission to prevent severe long-term outcomes of RA. Remission can be achieved in a third of patients with early RA using a combination of conventional DMARDs, including methotrexate, sulfasalazine, hydroxychloroquine, and prednisolone. Of patients with early RA, 20% to 30% do not improve enough with conventional treatments and should be identified at early phases to consider institution of biologic agents. 相似文献
78.
Pekka Jaako Shubhranshu Debnath Karin Olsson Ute Modlich Michael Rothe Axel Schambach Johan Flygare Stefan Karlsson 《Haematologica》2014,99(12):1792-1798
Diamond-Blackfan anemia is a congenital erythroid hypoplasia caused by functional haploinsufficiency of genes encoding ribosomal proteins. Mutations involving the ribosomal protein S19 gene are detected in 25% of patients. Enforced expression of ribosomal protein S19 improves the overall proliferative capacity, erythroid colony-forming potential and erythroid differentiation of hematopoietic progenitors from ribosomal protein S19-deficient patients in vitro and in vivo following xenotransplantation. However, studies using animal models are needed to assess the therapeutic efficacy and safety of the viral vectors. In the present study we have validated the therapeutic potential of gene therapy using mouse models of ribosomal protein S19-deficient Diamond-Blackfan anemia. Using lentiviral gene transfer we demonstrated that enforced expression of ribosomal protein S19 cures the anemia and lethal bone marrow failure in recipients transplanted with ribosomal protein S19-deficient cells. Furthermore, gene-corrected ribosomal protein S19-deficient cells showed an increased pan-hematopoietic contribution over time compared to untransduced cells without signs of vector-mediated toxicity. Our study provides a proof of principle for the development of clinical gene therapy to cure ribosomal protein 19-deficient Diamond-Blackfan anemia. 相似文献
79.
Lassila Lippo Säilynoja Eija Prinssi Roosa Vallittu Pekka Garoushi Sufyan 《Odontology / the Society of the Nippon Dental University》2019,107(3):342-352
Odontology - This study aimed to evaluate certain physical properties including surface wear of a new experimental short fiber-reinforced flowable resin composite (SFRC) in comparison with... 相似文献
80.
Heta Moustgaard Kaisla Joutsenniemi Pekka Martikainen 《Social psychiatry and psychiatric epidemiology》2014,49(1):15-25