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31.
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
32.
33.
Mandelin J Li TF Hukkanen M Liljeström M Salo J Santavirta S Konttinen YT 《The Journal of rheumatology》2005,32(4):713-720
34.
Ibrahim Danad Valtteri Uusitalo Tanja Kero Antti Saraste Pieter G. Raijmakers Adriaan A. Lammertsma Martijn W. Heymans Sami A. Kajander Mikko Pietilä Stefan James Jens Sörensen Paul Knaapen Juhani Knuuti 《Journal of the American College of Cardiology》2014
Background
Recent studies have demonstrated improved diagnostic accuracy for detecting coronary artery disease (CAD) when myocardial blood flow (MBF) is quantified in absolute terms, but there are no uniformly accepted cutoff values for hemodynamically significant CAD.Objectives
The goal of this study was to determine cutoff values for absolute MBF and to evaluate the diagnostic accuracy of quantitative [15O]H2O positron emission tomography (PET).Methods
A total of 330 patients underwent both quantitative [15O]H2O PET imaging and invasive coronary angiography in conjunction with fractional flow reserve measurements. A stenosis >90% and/or fractional flow reserve ≤0.80 was considered obstructive; a stenosis <30% and/or fractional flow reserve >0.80 was nonobstructive.Results
Hemodynamically significant CAD was diagnosed in 116 (41%) of 281 patients who fulfilled study criteria for CAD. Resting perfusion was 1.00 ± 0.25 and 0.92 ± 0.23 ml/min/g in regions supplied by nonstenotic and significantly stenosed vessels, respectively (p < 0.001). During stress, perfusion increased to 3.26 ± 1.04 ml/min/g and 1.73 ± 0.67 ml/min/g, respectively (p < 0.001). The optimal cutoff values were 2.3 and 2.5 for hyperemic MBF and myocardial flow reserve, respectively. For MBF, these cutoff values showed a sensitivity, specificity, and accuracy for detecting significant CAD of 89%, 84%, and 86%, respectively, at a per-patient level and 87%, 85%, and 85% at a per-vessel level. The corresponding myocardial flow reserve values were 86%, 72%, and 78% (per patient) and 80%, 82%, and 81% (per vessel). Age and sex significantly affected diagnostic accuracy of quantitative PET.Conclusions
Quantitative MBF measurements with the use of [15O]H2O PET provided high diagnostic performance, but both sex and age should be taken into account. 相似文献35.
Mari Aikio Harri Elamaa David Vicente Valerio Izzi Inderjeet Kaur Lotta Seppinen Helen E. Speedy Dorota Kaminska Sanna Kuusisto Raija Sormunen Ritva Heljasvaara Emma L. Jones Mikko Muilu Matti Jauhiainen Jussi Pihlajam?ki Markku J. Savolainen Carol C. Shoulders Taina Pihlajaniemi 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(30):E3043-E3052
36.
Satu Lnnrot Valtteri Suorsa Johanna Paajanen Timo Hatanp Mikko Ritala Risto Koivula 《RSC advances》2019,9(39):22355
Mesoporous and large surface area zirconium oxide aggregate granules with good adsorption properties were synthesized using a simple precipitation method. Since utilization of these small and fragile particles is considered rather difficult in larger scale column operation, the product was formed into a fibrous form to improve its usability. The submicron fibers were obtained from an optimized electroblowing synthesis that resulted in elastic and uniform fibers with a tetragonal structure and high length-to-diameter ratio. In antimonate (Sb(v)) adsorption experiments, the higher calcination temperature (350 °C) of the fibers did not seem to decrease the Sb(v) adsorption capacity excessively since the high theoretical adsorption capacities were 113 mg g−1 and 58 mg g−1 for the aggregate and fibers, respectively. Both materials had fast kinetics, fibers being faster in the beginning of the reaction. Moreover, both materials offered efficient Sb(v) removal in the studied pH range from 1 to 11 by reaching over 99.9% adsorption in the optimal pH range. X-ray absorption near edge spectroscopy (XANES) revealed that Sb(v) stays as pentavalent antimony after being adsorbed by these materials and based on the isoelectric point shifts in the zeta potential measurement, adsorption occurs mainly by an inner-sphere complexation reaction. Finally, our study showed that pressure buildup in a flow-through column packed with zirconium oxide fibers was significantly lower than in a column packed with aggregates. Thus, zirconium oxide aggregates can be formed into submicron fibers with enhanced column operation properties without a too large compromise in the adsorption properties.Zirconium oxide was formed into submicron fibers to improve the Sb(v) separation performance compared to a conventional aggregate material. 相似文献
37.
Ola Ekström Kristoffer Ström Bilal Ahmad Mir Esa Laurila Ylva Wessman Mikko Lehtovirta Karl-Fredrik Eriksson Ola Hansson 《Clinical physiology and functional imaging》2023,43(4):271-277
Aim
Tenascin C (TNC) is a large extracellular matrix glycoprotein. It is involved in development and upregulated both during tissue repair and in several pathological conditions, including cardiovascular disease. Extracellular matrix proteins play a role in promoting exercise responses, leading to adaptation, regeneration, and repair. The main goal of this study was to investigate whether a short anaerobic effort leads to increased levels of TNC in serum.Methods
Thirty-nine healthy men performed a Wingate test followed by a muscle biopsy. Myoblasts were isolated from the muscle biopsies and differentiated to myotubes ex vivo. TNC RNA was quantified in the biopsies, myotubes and myoblasts using RNA sequencing. Blood samples were drawn before and 5 min after the Wingate test. Serum TNC levels were measured using enzyme-linked immunosorbent assay.Results
After the Wingate test, serum TNC increased on average by 23% [15–33], median [interquartile range]; PWilcoxon < 0.0001. This increase is correlated with peak power output and power drop, but not with VO2max. TNC RNA expression is higher in myoblasts and myotubes compared to skeletal muscle tissue.Conclusion
TNC is secreted systemically as a response to the Wingate anaerobic test in healthy males. The response was positively correlated with peak power and power drop, but not with VO2max which implicates a relation to mechanical strain and/or blood flow. With higher expression in undifferentiated myoblast cells than muscle tissue, it is likely that TNC plays a role in muscle tissue remodelling in humans. Our findings open for research on how TNC contributes to exercise adaptation. 相似文献38.
Nazario Rubio Maria-Angeles Arevalo Marie Cerciat Francisco Sanz-Rodriguez Mikko Unkila Luis Miguel Garcia-Segura 《Journal of neurovirology》2014,20(5):485-495
Theiler’s murine encephalomyelitis virus (TMEV) induces demyelination in susceptible strains of mice (SJL/J) through an immunopathological process that is mediated by CD4+ Th1 T cell. These T cells are chemoattracted to the central nervous system by chemokines. Hence, in this study, we focused on the production of the chemokine “interferon-gamma-inducible protein 10 kDa,” or IP-10/CXCL10, by cultured SJL/J mouse astrocytes infected with the BeAn strain of TMEV and its capacity to attract activated T cells. The analysis of the whole murine genome by DNA hybridization with cRNAs from mock- and TMEV-infected cultures revealed the upregulation of six sequences that potentially encode for CXCL10. This increased CXCL10 expression was validated by PCR and qPCR. The presence of this chemokine was further demonstrated by enzyme-linked immunoassay (ELISA). Significantly, astrocytes from BALB/c mice, a strain resistant to demyelination, did not produce CXCL10. The secreted CXCL10 was biologically active, inducing chemoattraction of activated lymphocytes. The inflammatory cytokines, IL-1α, IFN-γ, and TNF-α, were strong inducers of CXCL10 in astrocytes. Serum from TMEV-infected SJL/J but not BALB/c mice contains CXCL10, the levels of which peak at the onset of the clinical disease. Finally, this in vitro inflammation model was fully inhibited by 17β-estradiol and four selective estrogen receptor modulators, as demonstrated by ELISA and qPCR. 相似文献
39.
Mikko Seppänen Hannele Koillinen Satu Mustjoki Mölkänen Tomi Kathleen E. Sullivan 《Journal of clinical immunology》2014,34(1):114-118
Purpose
We report a 45-year old female adult patient with terminal deletion of chromosome 11q resulting in clinical phenotype of late-onset combined immunodeficiency.Methods
We describe the clinical phenotype and discuss the similarities between our patient and those with chromosome 22q11.2 deletion syndrome. Immunological evaluation included immunoglobulin levels, vaccine responses, number and function of T, NK and B cell subsets and comparative genomic hybridization test of blood and fibroblasts.Results
The patient suffered from recurrent pneumococcal pneumonia and genital and cutaneous condylomas. She had a history of learning difficulties, dysmorphic features, autoimmune thyroiditis, chronic thrombocytopenia and severe asthma. We found Paris-Trousseau type thrombocytopenia, B-, T- and NK-lymphopenia, T cell oligoclonality and IgG hypogammaglobulinemia with inability to respond to pneumococcal polysaccharide, tetanus and diphtheria vaccines. A terminal deletion of chromosome 11q compatible with partial Jacobsen syndrome was found.Conclusions
This confirms Jacobsen syndrome as a chromosome deletion syndrome able to cause combined immunodeficiency. 相似文献40.
Sachin Kochrekar Ajit Kalekar Shweta Mehta Pia Damlin Mikko Salomki Sari Granroth Niko Meltola Kavita Joshi Carita Kvarnstrm 《RSC advances》2021,11(32):19844
This study reports the electropolymerization of novel keto functionalized octaethyl metal porphyrins (Zn2+ and Ni2+) in the presence of 4,4′-bipyridine (4,4′-bpy) as a bridging nucleophile. The polymer films were characterized by electrochemical, spectroscopic (UV-Vis, XPS, FT-IR and Raman spectroscopy) and imaging (AFM and SEM) techniques. The absorption and electronic spectra confirm the presence of both porphyrin and 4,4′-bipyridine units in the film. The surface morphology reveals homogeneous film deposition with average roughness values of approx. 8 nm. The theoretical studies performed offered insights into the interplay of different metal centres (Zn2+ and Ni2+) and the keto functionality of the porphyrin unit in the formation of copolymer films. The electrochemical interaction of polymer films with CO2 suggests a reversible trap and release of CO2 with low energy barriers for both the polymers.Electropolymerization of keto functionalized porphyrins and 4,4′-bipyridine. 相似文献