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39632. Moderate alcohol consumption and triglyceridemia

Creator:
Kovář, J. and Zemánková, K.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, ethanol, lipoproteiny, lipoproteins, alcohol consumption, triglyceride, lipoprotein lipase, 14, and 612
Language:
English
Description:
The review aims to summarize current knowledge on the effects of moderate alcohol consumption ( 1 standard drink a day for women; 2 drinks a day for men) on triglyceride concentration in circulation. Current evidence suggests that the relationship between alcohol consumption and triglyceridemia is J -shaped. Triglyceridemia is lowest in subjects who drink 10 -20 g/alcohol a day. Such a J -shaped association is comparable with that described for the relationship between alcohol and cardiovascular risk. On the contrary, alcohol taken with a meal increases and prolongs postprandi al triglyceridemia. Such effects of alcohol consumption may be at least partially explained by the effects of ethanol on lipoprotein lipase (LPL) activity. Long -term moderate alcohol consumption increases LPL activity, which may explain its TG -lowering effect. On the other hand, LPL activity is acutely downregulated by ethanol, which explains increased postprandial triglyceridemia., J. Kovář, K. Zemánková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

39633. Moderate alcohol consumption and vitamin C status in the guinea-pig and the rat

Creator:
Zloch, Z. and Ginter, E.
Type:
article, model:article, and TEXT
Subject:
vitamin C biosynthesis and metabolism and ethanol consumption
Language:
English
Description:
The influence of regular moderate ethanol consumption on the status of vitamin C was followed in guinea-pigs and rats. In the guinea-pigs examined, 10-day consumption of ethanol (4.5 g per day and kg of body weight), administered in drinking water under a vitamin C-deficient diet, caused a greater decrease in the tissue concentrations and the body-pool of this vitamin than in the group without alcohol. In the rats, on the contrary, the daily consumption of ethanol (6 % vol) during 10 months resulted in an increase in the body stores of vitamin C, especially in the liver, adrenals, kidneys, and lungs. Moreover, the biosynthesis of ascorbate from D- glucuronolactone in vitro was more intensive (by 30 %) in the liver microsomes of alcoholized rats than in those of controls (without alcohol). These results indicate that the need of vitamin C during chronic consumption of moderate alcohol doses is enhanced. This is due to the participation of ascorbate in oxidoreducing processes connected with ethanol metabolism which leads to its irreversible destruction. In the rat, this loss is compensated by its enhanced biosynthesis, while in the guinea-pig it produces increased demands for its exogenous intake. If these are not satisfied, a partial vitamin C deficiency may occur, which potentiates the harmful effect of alcohol on the health status.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

39634. Moderate exercise based on artificial gravity preserves orthostatic tolerance and exercise capacity during short-term head-down bed rest

Creator:
Li, X.-T., Yang, C.-B., Zhu, Y.-S., Sun, J., Shi, F., Wang, Y.-C., Gao, Y., Zhao, J.-D., and Sun, X.-Q.
Format:
print, bez média, and svazek
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, short arm centrifuge, microgravity, maximal oxygen consumption, anaerobic threshold, cardiovascular function, heart rate variability, 14, and 612
Language:
English
Description:
Numerous countermeasures have been proposed to minimize microgravity-induced physical deconditioning, but their benefits are limited. The present study aimed to investigate whether personalized aerobic exercise based on artificial gravity (AG) mitigates multisystem physical deconditioning. Fourteen men were assigned to the control group (n=6) and the countermeasure group (CM, n=8). Subjects in the CM group were exposed to AG (2 Gz at foot level) for 30 min twice daily, during which time cycling exercise of 80-95 % anaerobic threshold (AT) intensity was undertaken. Orthostatic tolerance (OT), exercise tests, and blood assays were determined before and after 4 days head-down bed rest (HDBR). Cardiac systolic function was measured every day. After HDBR, OT decreased to 50.9 % and 77.5 % of pre-HDBR values in control and CM groups, respectively. Exercise endurance, maximal oxygen consumption, and AT decreased to 96.5 %, 91.5 % and 91.8 % of pre-HDBR values, respectively, in the control group. Nevertheless, there were slight changes in the CM group. HDBR increased heart rate, sympathetic activity, and the pre-ejection period, but decreased plasma volume, parasympathetic activity and left-ventricular ejection time in the control group, whereas these effects were eliminated in the CM group. Aldosterone had no change in the control group but increased significantly in the CM group. Our study shows that 80-95 % AT aerobic exercise based on 2 Gz of AG preserves OT and exercise endurance, and affects body fluid regulation during short-term HDBR. The underlying mechanisms might involve maintained cardiac systolic function, preserved plasma volume, and improved sympathetic responses to orthostatic stress., X.-T. Li, C.-B. Yang, Y.-S. Zhu, J. Sun, F. Shi, Y.-C. Wang, Y. Gao, J.-D. Zhao, X.-Q. Sun., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

39635. Moderate-intensity exercise training reduces vasorelaxation of mesenteric arteries: role of BKCa channels and nitric oxide

Creator:
Al-Dhuhli, Farid, Al-Siyabi, Sultan, Al-Maamari, Hamed, Al-Farsi, Said, and Albarwani, Sulayma
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
exercise training, mesenteric arteries, large conductance calcium-activated potassium channel, vascular smooth muscle cells, and nitric oxide
Language:
English
Description:
Exercise training (ET) is well established to induce vascular adaptations on the metabolically active muscles. These adaptations include increased function of vascular potassium channels and enhanced endothelium-dependent relaxations. However, the available data on the effect of ET on vasculatures that normally constrict during exercise, such as mesenteric arteries (MA), are scarce and not conclusive. Therefore, this study hypothesized that 10 weeks of moderate-intensity ET would result in adaptations towards more vasoconstriction or/and less vasodilatation of MA. Young Fischer 344 rats were randomly assigned to a sedentary group (SED; n=24) or exercise training group (EXE; n=28). The EXE rats underwent a progressive treadmill ET program for 10 weeks. Isometric tensions of small (SED; 252.9±29.5 µm, EXE; 248.6±34.4 µm) and large (SED; 397.7±85.3 µm, EXE; 414.0±86.95 µm) MA were recorded in response to cumulative phenylephrine concentrations (PE; 0-30 µM) in the presence and absence of the BKCa channel blocker, Iberiotoxin (100 nM). In another set of experiments, tensions in response to cumulative concentration-response curves of acetylcholine (ACh) or sodium nitroprusside (SNP) were obtained, and pEC50s were compared. Immunoblotting was performed to measure protein expression levels of the BKCa channel subunits and eNOS. ET did not alter the basal tension of small and large MA but significantly increased their responses to PE, and reduced the effect of BKCa channels in opposing the contractile responses to PE without changes in the protein expression level of BKCa subunits. ET also elicited a sizedependent functional adaptations that involved reduced endothelium-independent and endothelium-dependent relaxations. In large MA the sensitivity to SNP was decreased more than in small MA suggesting impaired nitric oxide (NO)-dependent mechanisms within the vascular smooth muscle cells of ET group. Whereas the shift in pEC50 of ACh-induced relaxation of small MA would suggest more effect on the production of NO within the endothelium, which is not changed in large MA of ET group. However, the eNOS protein expression level was not significantly changed between the ET and SED groups. In conclusion, our results indicate an increase in contraction and reduced relaxation of MA after 10 weeks of ET, an adaptation that may help shunt blood flow to metabolically active tissues during acute exercise.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

39636. Moderately elevated temperature eliminates resistance of rice plants with enhanced expression of glutathione reductase to intensive photooxidative stress

Creator:
Kouřil, R., Lazár, D., Lee, H., Jo, J., and Nauš, J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
active oxygen species, chlorophyll fluorescence, Oryza sativa, photochemical and non-photochemical fluorescence quenching, and transgenic plants
Language:
Multiple languages
Description:
We developed transgenic rice plants (Oryza sativa L. cv. Daeribbyeo) overproducing cytosolic glutathione reductase (GR) using a GR gene from Brassica campestris and studied their response to photo-oxidative stress in the presence of methyl viologen (MV, 10 and 50 μM concentrations) under room (25 °C) and moderately elevated (35 °C) temperature by analysis of chlorophyll (Chl) a fluorescence parameters (FV/FM, qN, and qP) and of Chl content. Elevated temperature enhanced and accelerated the photo-oxidative damage to photosynthetic apparatus expressed mainly by a fast decrease of qN. Higher temperature supported the protective reaction in transformed rice plants for lower MV concentration (10 μM) and eliminated the enhanced tolerance of photosystem 2 photochemistry to photooxidative stress for higher (50 μM) MV concentration. Different mechanisms and temperature dependence of oxidative and protective reactions explain the results. and R. Kouřil ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

39637. Modern vertical crustal movements of the Southern Baltic coast from tide gauge, satellite altimetry and GNSS observations

Creator:
Kowalczyk , Kamil, Pajak, Katarzyna, and Naumowicz, Bartosz
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vertical crustal movements, tide gauge, geocentric sea level changes, and satellite altimetry
Language:
English
Description:
In this study, the vertical crustal movements of the southern Baltic coast were determined based on two independent methods: tide gauge and GNSS observations. The mean sea level change trends were determined from five tide gauge observations and satellite altimetry data along the Polish coastal zone. The vertical crustal movements at nearby GNSS stations were also determined. We used the tide gauge water level data from the Permanent Service for Mean Sea Level (PSMSL) and from the Institute of Meteorology and Water Management National Research Institute, Poland (1951-2017 and 1993-2017) as well as sea level anomalies obtained from the Copernicus Marine and Environment Monitoring Service (CMEMS) (1993-2017). The time series for GNSS stations eveloped with the PPP technique obtained from Nevada Geodetic Laboratory (NGL) and last - squares approach were used for the analysis. The results provide a view of the absolute vertical crustal movements of the Polish coast. The absolute vertical crustal movements, calculated from tide gauge data and satellite altimetry for the time period between 1951-2017 ¬– from +2.20 mm/yr ±0.42 mm/yr to +2.68 mm/yr ±0.31 mm/yr. A comparison was made, and it showed that the absolute movements determined from two data sets were different. This may be a consequence of several factors: short and incomplete time series, other unidentified movements of a GNSS station, a tide gauge of own movements, human activity, geological and hydrological factors, the method of the time series elaboration and of the data used to work out the vertical crustal movements. It is thought that the results are very significant despite the existing differences in the absolute crustal movements, because the sea level is a unique index in studies of climate impact on all changes on the Earth and crustal movements are closely linked to it.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

39638. Moderné astronomické prístroje a metódy

Creator:
Koza, Július
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
astronomické přístroje, astronomical instruments, 6, and 520
Language:
Czech and English
Description:
Príspevok je pokusom stručne charakterizovat rozsiahly arzenál súčasných astronomických prístrojov a metód s krátkym presahom do blízkej budúcnosti. Podstatným znakom astronomického výskumu je multispektrálnosť s nasadením kozmických observatórií. Vel'ký pozemský optický teleskop už sám o sebe nestačí a k dosiahnutiu perfektného obrazu daného difrakčným limitom je nevyhnutná aktívna a adaptívna optika s následnou rekonštrukciou obrazu založenou na Fourierovej transformácii. Interpretačným nástrojom napomáhajúcim pochopiť a vysvetliť pozorovania sú počítačové numerické simulácie. Vybrané vzorky sú kompromisom poznačeným profesionálnym zameraním autora na fyziku Slnka v najlepšej snahe zachovať ich všeobecnejšiu platnosť., The review attempts to characterize briefly a vast arsenal of contemporary astronomical instruments and methods with an outlook to the near future. Essential features of astronomical research are multispectral observations involving both ground and space observatories. Big ground-based telescope in itself is no longer sufficient. Supporting active and adaptive optics with follow-up post-processing and image reconstruction based on Fourier transform are needed to achieve perfect diffraction-limited image. Numerical simulations are essential tools in interpretation and explanation of observations. Presented samples are influenced by the author's specialization in solar physics but he seeks to maintain their generic validity., Július Koza., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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