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28244. Varieties of idempotent slim groupoids

Creator:
Ježek, Jaroslav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
groupoid, variety, and nonfinitely based
Language:
English
Description:
Idempotent slim groupoids are groupoids satisfying $xx\=x$ and $x(yz)\=xz$. We prove that the variety of idempotent slim groupoids has uncountably many subvarieties. We find a four-element, inherently nonfinitely based idempotent slim groupoid; the variety generated by this groupoid has only finitely many subvarieties. We investigate free objects in some varieties of idempotent slim groupoids determined by permutational equations.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

28245. Various AKIP1 expression levels affect its subcellular localization but have no effect on NF-κB activation

Creator:
Keprová, A., Kořínková, L. , Křížová, I. , Hadravová, R., Kaufman, F., Pichová, I. , Ruml, T., and Rumlová, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
AKIP1, BCA3, protein aggregation, NF-kappa B, and transcription regulation
Language:
English
Description:
A-kinase interacting protein 1 (AKIP1) has been shown to interact with a broad range of proteins involved in various cellular processes, including apoptosis, tumorigenesis, and oxidative stress suggesting it might have multiple cellular functions. In this study, we used an epitope-tagged AKIP1 and by combination of immunochemical approaches, microscopic methods and reporter assays we studied its properties. Here, we show that various levels of AKIP1 overexpression in HEK-293 cells affected not only its subcellular localization but also resulted in aggregation. While highly expressed AKIP1 accumulated in electron-dense aggregates both in the nucleus and cytosol, low expression of AKIP1 resulted in its localization within the nucleus as a free, non-aggregated protein. Even though AKIP1 was shown to interact with p65 subunit of NF-κB and activate this transcription factor, we did not observe any effect on NF-κB activation regardless of various AKIP1 expression level.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

28246. Various aspects of sex and gender bias in biomedical research

Creator:
Plevkova, Jana, Brozmanova, Mariana, Harsanyiova, Jana, Sterusky, Miroslav, Honetschlager, Jan, and Buday, Tomas
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
sex bias, biomedical research, testosterone, and estrogen
Language:
English
Description:
The main role of research in medicine is to provide relevant knowledge which, after successful translation to clinical practice, improves the quality of healthcare. The sex bias which is still present in the majority of research disciplines prefers male subjects despite legislation changes in the US grant agencies and European research programme Horizon 2020. Male subjects (cells, animals) still dominate in preclinical research and it has detrimental consequences for women’s health and the quality of science. Opposite bias exists for data obtained mainly in animal models utilizing female subjects (e.g. research in multiple sclerosis, osteoporosis) with skewed outcomes for men affected by these diseases. Either way, scientists are producing results which compromise half of the population. Assumptions that females as cohorts are more variable and another assumption that the oestrous cycle should be tracked in case the females are enrolled in preclinical studies were proven wrong. Variability of male versus female cohorts are comparable and do not only stem from hormonal levels. The widespread prevalence of sex differences in human diseases ultimately requires detailed experiments performed on both sexes, unless the studies are specifically addressing reproduction or sex-related behaviors.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

28247. Various types of dry friction characteristics for vibration damping

Creator:
Půst, Ladislav, Pešek, Luděk, and Radolfová, Alena
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
dry friction, stick-slip motion, modified Coulomb law, equivalent linearization, equivalent stiffness, and equivalent damping coefficient
Language:
English
Description:
Paper deals with derivation of mathematical relationships of dry friction force versus relative velocity in friction contact of two bodies. It is focused on such main types of dry friction characteristics, which frequently occur in dynamic mechanical systems. New models of modified Coulomb friction law and spring - friction elements are determined. For easy application in computing programs used in technical practice and based on linear equations, the equivalent linear stiffness and damping expressions are formulated and analysed in detail. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

28248. Vascular effect of red wine polyphenols in chronic stress-exposed Wistar-kyoto rats

Creator:
Púzserová , A., Csizmadiová , Z. , Andriantsitohaina , R., and Bernátová, I.
Type:
article, model:article, and TEXT
Subject:
Crowding, Chronic social stress, Provinols TM, Blood pressure, and Nitric oxide
Language:
English
Description:
Present study investigated the effect of red wine polyphenolic compounds (ProvinolsTM) on blood pressure (BP), nitric oxide synthase (NOS) activity and vascular function in Wistar-Kyoto (WKY) rats exposed to chronic social stress produced by crowding. Adult male rats were divided into four groups: control (480 cm2/rat), ProvinolsTM-treated (20 mg/kg/day, 480 cm2/rat), crowded (200 cm2/rat) and crowded treated with Provinols TM (20 mg/kg/day, 200 cm2/rat) for 8 weeks. No differences in BP were observed among the groups at the end of experiment, however, reduced BP was observed in ProvinolsTM-treated rats after 3 weeks of treatment. NOS activity in the aorta was significantly elevated in crowded rats, while ProvinolsTM alone had no effect on nitric oxide (NO) production. Acetylcholine-induced relaxation of the femoral artery was significantly improved in stressed and ProvinolsTM-treated rats vs. control, without significant changes in their noradrenaline-induced vasoconstriction. Interestingly, ProvinolsTM blunted the elevation of NO production and vasorelaxation during crowding. Increased endothelium-dependent vasorelaxation and NO synthesis in crowded rats may represent the adaptation mechanisms, resulting in unaltered blood pressure in stress-exposed normotensive rats. This study further demonstrated that elevated release of NO during chronic stress may be prevented by ProvinolsTM. Thus, Provino TM might maintain equilibrium between endothelium-derived vasoconstrictor and vasodilator factors in stress.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

28249. Vascular metabolic dysfunction and lipotoxicity

Creator:
Mattern, H. M. and Hardin, C. D.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, cévní, apoptóza, physiology, smooth muscles, apoptosis, hladké svaly cév, palmitát, oleát, reaktivní formy kyslíku, vascular smooth muscle, palmitate, oleate, reactive oxygen species, 14, and 612
Language:
English
Description:
The purpose of this study was to determine the role of lipotoxicity in vascular smooth muscle (VSM). C1-BODIPY 500/510 C12 used to assess the ability of VSM A7r5 cells to transport long-chain fatty acids showed that lipid transport did not appear to limit metabolism. Thin layer chromatography revealed that storage of transported fatty acid occurred primarily as mono- and diglycerides and fatty acids but not as triglycerides. We used lipid-induced apoptosis as a measure of lipotoxicity and found that 1.5 mM palmitate (6.8:1) bound to albumin resulted in a 15-fold increase in the number of apoptotic cells compared to the control at 24 hours. This apoptosis did not seem to be due to an increase in reactive oxygen species (ROS) since VSM cells incubated in palmitate showed less ROS production than cells incubated in albumin only. Similar exposure to oleate did not significantly increase the number of apoptotic cells compared to the control. Oleate actually significantly attenuated the apoptosis induced by palmitate, suggesting that unsaturated fatty acids have a protective effect on cells undergoing palmitate-induced apoptosis. These results suggest that vascular smooth muscle is vulnerable to lipotoxicity and that this lipotoxicity may play a role in the development of atherosclerosis., H. M. Mattern, C. D. Hardin., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

28250. Vascular responses after long-term inhibition of nitric oxide synthesis in newborn dogs

Creator:
Török, J. and Gerová, M.
Type:
article, model:article, and TEXT
Subject:
newborn dogs, long-term inhibition, nitric oxide, endothelium-dependent relaxation, and neurogenic contraction
Language:
English
Description:
The effect of long-term inhibition of nitric oxide synthase on the relaxation and contraction ability of the thoracic aorta, carotid and pulmonary arteries was studied in the early postnatal period. Starting from the fifth day after birth, puppies were administered NG-nitro-L-arginine methyl ester (L-NAME, 50 mg/kg/day subcutaneously) for 6 weeks. After this period, mean blood pressure increased from the control value of 94±14 mm Hg to 168±5 mm Hg (P<0.01) and the heart/body weight ratio from 6.22±0.25 to 8.23±0.45 (PcO.Ol). In control arterial rings precontracted by phenylephrine (10“5 mol/1), acetylcholine caused dose-dependent relaxations; the maximal values were reached in the range of 10 "8 to 10"* mol/1. In arteries from L-NAME treated puppies, acetylcholine also induced dose-dependent relaxations, the maximum values in the thoracic aorta (81.0±2.9 %) and carotid artery (87.2±6.9 %) were significantly reduced, not, however, in the pulmonary artery (76.4±7.8 %). Dose-response curves to acetylcholine in all the examined arteries from L-NAME-treated animals were shifted to the right indicating a decrease in sensitivity to acetylcholine. Neurogenic contractions, induced by electrical stimulation of adrenergic nerves, were not significantly altered in the thoracic aorta and carotid artery. However, in the pulmonary artery the contractions were greater at high frequency of stimulation. The findings that (i) submaximal doses of L-NAME attenuate acetylcholine-induced relaxation only slightly, and (ii) that it does not appreciably influence adrenergic contractions justify the hypothesis that the endothelium of vessels in newborn dogs is very probably endowed with a high content of nitric oxide synthase.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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