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排序方式: 共有209条查询结果,搜索用时 15 毫秒
1.
Pagot E Fiedler S Cloetens P Bravin A Coan P Fezzaa K Baruchel J Härtwig J von Smitten K Leidenius M Karjalainen-Lindsberg ML Keyriläinen J 《Physics in medicine and biology》2005,50(4):709-724
Two x-ray phase contrast imaging techniques are compared in a quantitative way for future mammographic applications: diffraction enhanced imaging (DEI) and phase propagation imaging (PPI). DEI involves, downstream of the sample, an analyser crystal acting as an angular filter for x-rays refracted by the sample. PPI simply uses the propagation (Fresnel diffraction) of the monochromatic and partially coherent x-ray beam over large distances. The information given by the two techniques is assessed by theoretical simulations and compared at the level of the experimental results for different kinds of samples (phantoms and real tissues). The imaging parameters such as the energy, the angular position of the analyser crystal in the DEI case or the sample to detector distance in the PPI case were varied in order to optimize the image quality in terms of contrast, visibility and figure of merit. 相似文献
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Marjut Rintala Seija Grénman Mirja Puranen Stina Syrj?nen 《Journal of clinical virology》2006,35(1):89-94
BACKGROUND: The natural history of genital human papillomavirus infection is well known, but nearly nothing is known about the outcome of oral HPV-infection. OBJECTIVES AND STUDY DESIGN: To study natural history of oral HPV in spouses during the follow-up 331 women (mean 25.5+/-3.4 years) and 131 men (mean 28.8+/-5.0 years) were recruited from maternity unit. Scrapings from healthy oral mucosa of spouses at baseline, 2, 6, 12 and 24 months and genital samples were taken for HPV testing. HPV DNA was detected by nested PCR and confirmed by hybridization using a cocktail of 12 high-risk (HR) oligoprobes. RESULTS: The detection rate of HR HPVs varied from 15% to 27%. Baseline oral HPV status between the spouses was closely related (odds ratio 4.3; 95% confidence interval 1.6-12.0; P=0.006). Persistent oral infection in one spouse was a significant risk factor (odds ratio 10.0; 95% confidence interval 1.5-68.7; P=0.005) for oral HR HPV persistence in the other partner. Cumulative incidence of new HR HPV infections was identical in both spouses, while men seemed to clear their infection more rapidly. In univariate survival analysis, the partner's oral or genital HPV status, oral sex habits or age did not predict clearance or acquisition of oral HR HPV. CONCLUSION: Natural history of HPV infection in oral mucosa mimics that of genital HPV infection. Oral sex had no association to oral HPV infection, but a persistent oral HPV infection of the spouse increased the risk of persistent oral HPV infection 10-fold in the other spouse. 相似文献
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Galina Sanaksenaho Annika Mutanen Nimish Godbole Maria Hukkinen Laura Merras-Salmio Reetta Kivisaari Antti Kyrönlahti Marjut Pihlajoki Jouko Lohi Markku Heikinheimo Mikko P Pakarinen 《Journal of pediatric surgery》2021,56(5):966-974
BackgroundIntestinal adaptation has been extensively studied experimentally, but very limited data is available on human subjects. In this study we assessed intestinal adaption in humans with short bowel syndrome (SBS).MethodsWe comparatively evaluated mucosal hyperplasia, inflammation, barrier function and nutrient transport using histology, immunohistochemistry and qPCR for selected 52 key genes in duodenal biopsies obtained from children with SBS after weaning off parenteral nutrition (n = 33), and matched controls without intestinal pathology (n = 12). Small bowel dilatation was assessed from contrast small bowel series.ResultsDuodenal mucosa of SBS children showed increased histologic inflammation of lamina propria (p = 0.033) and mucosal mRNA expression of tumor necrosis factor (p = 0.027), transforming growth factor (TGF)-β2 (p = 0.006) and caveolin-1 (CAV1; p = 0.001). Villus height, crypt depth, enterocyte proliferation, apoptosis and expression of proliferation and nutrient transport genes remained unchanged. Pathologic small bowel dilatation reduced crypt depth (p = 0.045) and downregulated mRNA expression of interleukin (IL)-6 by three-fold (p = 0.008), while correlating negatively with IL6 (r = -0.609, p = 0.004). Loss of ileocecal valve (ICV) upregulated mRNA expression of toll-like receptor 4 (TLR4), TGF-β1, CAV1, several apoptosis regulating genes, and mRNA expression of zonulin (p < 0.05 for all).ConclusionsDespite successful adaptation to enteral autonomy, duodenal mucosa of SBS children displayed histologic and molecular signs of abnormal inflammation and regulation of epithelial permeability, whereas no structural or molecular signs of adaptive hyperplasia or enhanced nutrient transport were observed. Excessive dilatation of the remaining small bowel paralleled impaired duodenal crypt homeostasis, while absence of ICV modified regulation of mucosal inflammation, regeneration and permeability.Level of evidenceII 相似文献
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One hundred patients with newly diagnosed multiple myeloma (MM) were treated with high-dose chemotherapy followed by single or double autologous stem cell transplantation (ASCT). Up-front treatment with a double ASCT tended to prolong progression-free and overall survival. 相似文献
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Sipilä K Kähönen M Salomaa V Päivänsalo M Karanko H Varpula M Jula A Kaaja R Kesäniemi YA Reunanen A Moilanen L 《Acta diabetologica》2012,49(3):215-223
The association between diabetes and subclinical atherosclerosis is well established. The effect of non-diabetic glucose intolerance on early atherosclerosis is not as straightforward, and the data regarding sex-related differences in this matter are limited. Therefore, our aim was to investigate these associations in men and women separately. We studied 1,304 Finnish men and women over 45?years of age who participated in the Finnish Health 2000 Survey. Ultrasonically determined carotid artery intima-media thickness and elasticity were used as markers of early atherosclerosis. Glucose tolerance was categorized according to the American Diabetes Association criteria for diabetes mellitus. Age-adjusted means for carotid artery intima-media thickness and elasticity indices were significantly (P?<?0.05) associated with glucose tolerance status in both sexes. There was a trend of increasing early atherosclerosis with the worsening of glucose tolerance in men and women. These associations were weakened in both sexes after further adjustments for other cardiovascular risk factors. In women, but not in men, significant (P?<?0.05) associations between glucose tolerance status and carotid artery elasticity were seen even after these further adjustments. Diabetes and non-diabetic glucose intolerance are associated with increased early carotid atherosclerosis compared with normal glucose tolerance in both sexes. Our results suggest that women with glucose intolerance may be in greater risk than men. 相似文献
9.
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
10.
OBJECTIVE: The purpose of this study was to develop and test a data-mining system for the online determination of mean DS, M, and FS or DMFS values per subject at different ages from electronic patient records at two health centers to see if there are north-south differences in oral health in Finland. MATERIAL AND METHODS: The mean index values were determined at two health centers using the codes of dental charts and progress notes of electronic dental records during the digital era of more than 10 years in a total of 153,619 subjects of all ages. Extracted teeth, as well as sound, carious, and restored tooth surfaces, were recorded from the dental charts. Treatments were then additionally registered from progress notes of the records when performed. RESULTS: The cumulative DS and FS values were similar in subjects under the age of 20 years at both health centers. In adults, caries was more abundant in northern Finland, where there was a higher number of restored surfaces (>40) registered, compared to only 30 in southern Finland at the age of 40 years. A high increase in the number of extractions began at age 45 in the north compared to age 70 in the south. These changes were clearly reflected in the DMFS index. CONCLUSIONS: Online determination of health parameters is a feasible methodology. The results revealed that north-south regional differences in dental health still occur in adults in Finland, but not in subjects younger than 20 years of age. 相似文献