200 research outputs found
Probing a Complex of Cytochromecand Cardiolipin by Magnetic Circular Dichroism Spectroscopy: Implications for the Initial Events in Apoptosis
Oxidation of cardiolipin (CL) by its complex with cytochrome c (cyt c) plays a crucial role in triggering apoptosis. Through a combination of magnetic circular dichroism spectroscopy and potentiometric titrations, we show that both the ferric and ferrous forms of the heme group of a CL:cyt c complex exist as multiple conformers at a physiologically relevant pH of 7.4. For the ferric state, these conformers are His/Lys- and His/OH–-ligated. The ferrous state is predominantly high-spin and, most likely, His/–. Interconversion of the ferric and ferrous conformers is described by a single midpoint potential of -80 ± 9 mV vs SHE. These results suggest that CL oxidation in mitochondria could occur by the reaction of molecular oxygen with the ferrous CL:cyt c complex in addition to the well-described reaction of peroxides with the ferric form
Assessment of physical activity of students and adolescents
This is article presents an assessment of physical activity in schoolchildren of grades 5, 9 and 1st year students. The study showed that the level of physical activity decreases with age. For example, the frequency of walking every day decreased from 63.3% (5th and 9th grade) to 28.7% (students). Among the surveyed students, the share of those engaged in sports sections decreased from 90% (5th grade) and 77.8% (9th grade) to 25%. In comparison with school students, the frequency and duration of physical activity decreases. The results obtained indicate the need to expand the number of sports sections in higher educational institutions, the availability of sports facilities, as well as the rational distribution of free time from studyВ данной статье представлена оценка физической активности у школьников 5, 9 классов и студентов 1 курса. Исследование показало, что уровень физической активности с возрастом снижается. Например, частота прогулок каждый день уменьшилась с 63,3% (5 и 9 класс) до 28,7% (студенты). Среди опрошенных студентов снизилась доля занимающихся в спортивных секциях с 90% (5 класс) и 77,8% (9 класс) до 25%. У студентов по сравнению со школьниками уменьшается кратность и продолжительность занятий физическими нагрузками. Полученные результаты свидетельствуют о необходимости расширения числа спортивных секций в высших учебных заведениях, доступности спортивных объектов, а также рационального распределения свободного времени от учеб
Comparative assessment of posture among 1st and 3rd year students of the medical and preventive faculty of the Ural state medical university
The purpose of the study is to identify and compare the features and patterns of posture disorders in students of the 1st and 3rd courses of the medical and preventive faculty of USMU.Цель исследования - выявить и сравнить особенности и закономерности нарушений осанки у студентов 1 и 3 курсов медико-профилактического факультета УГМУ
Study of the psychophysiological state of students of the medical and preventive faculty of USMU on distance learning
The aim of the study – to assess the psychophysiological state of students of the Faculty of Medicine and Prevention who were on distance learning in connection with the pandemic.Цель исследования – оценить психофизиологическое состояние студентов медико-профилактического факультета, находившихся на дистанционной форме обучения в связи с пандемией
Absorption, Photoluminescence, and Polarized Raman Spectra of a Fourfold Alkoxy-Substituted Phthalocyanine Liquid Crystal
Relativistic Laser-Matter Interaction and Relativistic Laboratory Astrophysics
The paper is devoted to the prospects of using the laser radiation
interaction with plasmas in the laboratory relativistic astrophysics context.
We discuss the dimensionless parameters characterizing the processes in the
laser and astrophysical plasmas and emphasize a similarity between the laser
and astrophysical plasmas in the ultrarelativistic energy limit. In particular,
we address basic mechanisms of the charged particle acceleration, the
collisionless shock wave and magnetic reconnection and vortex dynamics
properties relevant to the problem of ultrarelativistic particle acceleration.Comment: 58 pages, 19 figure
Phosphatidylserine Targets Single-Walled Carbon Nanotubes to Professional Phagocytes In Vitro and In Vivo
Broad applications of single-walled carbon nanotubes (SWCNT) dictate the necessity to better understand their health effects. Poor recognition of non-functionalized SWCNT by phagocytes is prohibitive towards controlling their biological action. We report that SWCNT coating with a phospholipid “eat-me” signal, phosphatidylserine (PS), makes them recognizable in vitro by different phagocytic cells - murine RAW264.7 macrophages, primary monocyte-derived human macrophages, dendritic cells, and rat brain microglia. Macrophage uptake of PS-coated nanotubes was suppressed by the PS-binding protein, Annexin V, and endocytosis inhibitors, and changed the pattern of pro- and anti-inflammatory cytokine secretion. Loading of PS-coated SWCNT with pro-apoptotic cargo (cytochrome c) allowed for the targeted killing of RAW264.7 macrophages. In vivo aspiration of PS-coated SWCNT stimulated their uptake by lung alveolar macrophages in mice. Thus, PS-coating can be utilized for targeted delivery of SWCNT with specified cargoes into professional phagocytes, hence for therapeutic regulation of specific populations of immune-competent cells
Fragmentation and Multifragmentation of 10.6A GeV Gold Nuclei
We present the results of a study performed on the interactions of 10.6A GeV
gold nuclei in nuclear emulsions. In a minimum bias sample of 1311 interac-
tions, 5260 helium nuclei and 2622 heavy fragments were observed as Au projec-
tile fragments. The experimental data are analyzed with particular emphasis of
target separation interactions in emulsions and study of criticalexponents.
Multiplicity distributions of the fast-moving projectile fragments are inves-
tigated. Charged fragment moments, conditional moments as well as two and three
-body asymmetries of the fast moving projectile particles are determined in
terms of the total charge remaining bound in the multiply charged projectile
fragments. Some differences in the average yields of helium nuclei and heavier
fragments are observed, which may be attributed to a target effect. However,
two and three-body asymmetries and conditional moments indicate that the
breakup mechanism of the projectile seems to be independent of target mass. We
looked for evidence of critical point observable in finite nuclei by study the
resulting charged fragments distributions. We have obtained the values for the
critical exponents gamma, beta and tau and compare our results with those at
lower energy experiment (1.0A GeV data). The values suggest that a phase
transition like behavior, is observed.Comment: latex, revtex, 28 pages, 12 figures, 3tables, submitted to Europysics
Journal
Local particle densities and global multiplicities in central heavy ion interactions at 3.7, 14.6, 60 and 200A GeV
Relationship of endothelial dysfunction and kidney functional state in patients with systemic sclerosis
Objective. To study vasoregulatory function of vascular wall in pts with systemic sclerosis (SS) and chronic scleroderma-related renal disease (SRD) and determine relationship with main measures of kidney functional state. Material and methods. 25 pts with SS (24 female) with mean age 46,4±10,7 years and mean disease duration 7,5±4,7 years were included. 24 pts (96%) had diffuse form and 17 pts (68%) – generalized stage of SS. 22 pts (88%) had chronic course of the disease with typical damage of vessels, heart, lungs and skin. SRD was revealed in 17 pts (68%). Sonographic method of Celermejer D. et al. (1992) was used for assessment of vascular endothelial function. 15 healthy persons without SS were included in control group. Results. Most prominent changes of brachial artery reactivity with insufficient vasodilatation and paradoxical vasoconstriction to reactive hyperemia were revealed in most pts with moderate and severe SRD. Conclusion. These changes of endothelium dependent and endothelium independent parameters in pts with SRD pointed to irreversible probably scleroderma-related vascular wall damage
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