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211.
Franz Pfeiffer Julia Herzen Marian Willner Michael Chabior Sigrid Auweter Maximilian Reiser Fabian Bamberg 《Zeitschrift für medizinische Physik》2013,23(3):176-185
In this review article we describe the development of grating-based X-ray phase-contrast imaging, with particular emphasis on potential biomedical applications of the technology. We review the basics of image formation in grating-based phase-contrast and dark-field radiography and present some exemplary multimodal radiography results obtained with laboratory X-ray sources. Furthermore, we discuss the theoretical concepts to extend grating-based multimodal radiography to quantitative transmission, phase-contrast, and dark-field scattering computed tomography. 相似文献
212.
Andrzej Nowicki Zbigniew Trawinski Barbara Gambin Wojciech Secomski Michał Szubielski Marzena Parol Robert Olszewski 《Ultrasound in medicine & biology》2018,44(6):1187-1197
A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Doppler probe was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD [%]) in two groups of patients after 5?min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean?±?standard deviation) was 15.26?±?4.90% (95% confidence interval [CI]: 13.32%–17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53?±?4.11% (95% CI: 2.42%–6.64%). Specifically, the ratio FMD/SR (mean?±?standard deviation), was equal to 5.36?×?10?4?±?4.64?×?10?4 (95% CI: 3.54?×?10?4 to 7.18?×?10?4) in group I and 1.38?×?10?4?±?0.89?×?10?4 (95% CI: 0.70?×?10?4 to 2.06?×?10?4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon–Mann–Whitney test for both FMD and FMD/SR (p?<0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease. 相似文献
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Tadeusz Włostowski Paweł Kozłowski Barbara Łaszkiewicz-Tiszczenko Ewa Oleńska Olgierd Aleksandrowicz 《Bulletin of environmental contamination and toxicology》2014,93(5):526-531
The objectives of this study were (1) to determine cadmium (Cd) accumulation in the midgut gland of a land snail Helix pomatia L. inhabiting residential areas of the 14 largest cities in Poland, and (2) to examine whether the accumulated Cd exerted any toxic effects. The average accumulation of Cd in the midgut gland of snails, weighing 16–18 g, ranged from 7.00 to 87.3 µg/g dry weight (0.06–0.77 µmol/g) and differed significantly among animals from the various urban areas. This difference in Cd accumulation was not related to city population, but was associated with the topsoil Cd (R2 = 0.868, p < 0.0001). The tissue Cd was not found to produce toxicity (histopathology, programmed cell death, lipofuscin formation or lipid peroxidation), probably due to the induction of sufficiently high quantities of metallothionein and glutathione, well-known protective molecules. 相似文献
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217.
Monika Drobna Bronisława Szarzyńska-Zawadzka Małgorzata Dawidowska 《Blood reviews》2018,32(6):457-472
T-cell acute lymphoblastic leukemia (T-ALL) is a rare, aggressive and heterogeneous malignancy originating from T-cell precursors. The mechanisms of T-ALL pathogenesis related to non-protein coding part of the genome are currently intensively studied. miRNAs are short, non-coding molecules acting as negative regulators of gene expression which shape phenotype of cells in a complex and context-specific manner. miRNAs may act as oncogenes or tumor suppressors; several miRNAs have been related to drug resistance and treatment response in various malignancies.Here we present the review of the state-of-the-art knowledge on the role of miRNAs in T-ALL pathogenesis, with detailed overview of the studies reporting on miRNAs with oncogenic and tumor suppressor potential. We discuss whether miRNAs might be considered candidate biomarkers of prognosis in T-ALL and leukemia subtype-specific markers. We also describe experimental approaches and a typical workflow applied in research on the involvement of miRNAs in oncogenesis. 相似文献
218.
Marcin Markowski Adam Kaliński Joanna Skwarska Jarosław Wawrzyniak Mirosława Bańbura Janusz Markowski Piotr Zieliński Jerzy Bańbura 《Bulletin of environmental contamination and toxicology》2013,91(3):302-305
The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than control nestlings. This result suggests that feathers can be used as reliable non-destructive bioindicators to assess the level of heavy metals originating from contaminated food, which is of great significance for comparative studies on ecological consequences of pollution. 相似文献
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