The contribution is a continuation of [2] which deals with analytic solution of torsion of a bar with simply connected profile, i.e. profile without holes. In this paper the case of multiply connected profile, i.e. profile with holes, is studied. The stress-strain analysis leads to the Airy stress function Φ. On boundary of each hole the function Φ has prescribed an unknown constant value completed with an integral condition. The mathematical model is also derived from the variational principle.
The second part of the paper contains solutions for the ring profile and for comparison also for incomplete ring profiles including the ‘broken‘ ring profile. The results are compared in tables and pictures. and Obsahuje seznam literatury
The contribution deals with strain-stress analysis of torsion of a non-circular bar. Mathematical model is exactly derived and solutions are introduced and visualised for cases of triangular, rectangular and some other profiles. and Obsahuje seznam literatury
The objective of our study was to assess the influence of mechanical ventilation on healthy body organs. Fifteen piglets (aged 6 weeks, 19-27 kg) were anesthetized, instrumented, and divided into three groups: Group A - spontaneously breathing, group B - mechanically ventilated with tidal volume 6 ml/kg, and group C - ventilated with tidal volume 10 ml/kg for 12 hours. The parameters of lung, heart, liver and kidney functions neurohumoral regulation and systemic inflammatory reaction were recorded initially (time-1) and after 12 hours (time-12) of mechanical ventilation. At the onset of experiment (time-1) the levels of soluble adhesive molecules were higher (CAM; P<0.01), glomerular filtration index and free water clearance were lower (P<0.05) in both ventilated groups than in group A. Right ventricle myocardial performance index was higher (RIMP; P<0.05) in group C when compared with group A. Levels of CAM (P<0.05) and creatinine clearance (P<0.01) were higher, free water clearance was lower (P<0.05) in group C when compared to group B. At time-12 the RIMP (P<0.05) and levels of CAM were increased (P<0.01), creatinine clearance was decreased (P<0.05) in both ventilated groups compared to the same parameter at time-1. Ventilation index was higher (P<0.05), and hypoxemic index was lower (P<0.01) in group C when compared to group B. In conclusion, this study showed that mechanical ventilation induced changes compatible with early inflammatory response in healthy animals. Higher tidal volumes had detrimental effect on ventilatory parameters, reduced myocardial performance and potentiated adverse reaction of other organs., J. Kobr ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Total carotenoids assessed spectrophotometrically in crude extracts may be considerably overestimated when high contents of phenolic compounds are co-extracted. In this case, the absorbance tails of phenolics extend well into the blue part of the spectrum, interfering with carotenoid estimation. Extracts of phenolic-rich organs, with a low ratio of photosynthetic to heterotrophic and/or supportive cells (for example, stems or twigs) are vulnerable to such pitfalls and may need chromatographic separation of carotenoids. and E. Levizou, Y. Petropoulou, Y. Manetas.
The present study investigated cardiac function in hearts of mice with total deficiency of the β1-, β2- and β3-adrenoceptors (TKO) in comparison to wildtype mice (WT). We investigated cardiac morphology and echocardiographic function, measured protein expression of Ca2+-regulatory proteins, SERCA 2a activity, myofibrillar function, and performed running wheel tests. Heart weight and heart-to-body weight ratio were significantly smaller in TKO as compared to WT. This was accompanied by a decrease in the size of the cardiomyocytes in TKO. Heart rate and ejection fraction were significantly diminished in TKO as compared to WT. Protein expressions of SERCA 2a, ryanodine receptor and Na+/Ca2+-exchanger were similar in TKO and WT mice, but phospholamban protein expression was increased. PKAdependent phosphorylation of phospholamban at serine 16 was absent and CaMKII-dependent phosphorylation at threonine 17 was decreased in TKO. All alterations were paralleled by a decrease in SERCA 2a-activity. A similar maximal calciumdependent tension but an increased myofibrillar calciumsensitivity was measured in TKO as compared to WT. We did not observe relevant functional impairments of TKO in running wheel tests. In the absence of β-agonistic stimulation, SERCA 2a activity is mainly regulated by alterations of phospholamban expression and phosphorylation. The decreased SERCA 2a activity following β-adrenoceptor deficiency may be partly compensated by an increased myofibrillar calcium-sensitivity., S. Lee ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy