This paper describes experimental work done on a prototype of in-pipe bristled minimachine, which locomotes in pipe with inner diameter under 40 mm. The principle of minimachine locomotion is based on difference friction force between bristle tip and pipe wall. The new bristle design and its mathematical and graphical model will be presented. and Obsahuje seznam literatury
High CO2 concentrations (HC) in air induce partial deactivation of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO, EC 4.1.1.39). Under saturating irradiance, increase in [CO2] to 1 200 cm3 m-3 reduces the concentration of operating carboxylation centres by 20–30 %. At a further increase in [CO2], the activity remained on the same level. Under limiting irradiance, the lowest activity was reached at 600 cm3 (CO2) m-3. The presence of oxygen diminished deactivation, but O2 failed to stimulate reactivation under high CO2. Conditions that favour oxygenation of ribulose-1,5- bisphosphate (RuBP) facilitated reactivation. Even HC did not act as an inhibitor. HC induces deactivation of RuBPCO by increasing the concentration of free reaction centres devoid of the substrate, which are more vulnerable to inhibition than the centres filled with substrates or products. and J. Viil ... [et al.].
This study aimed to evaluate the changes in the erythropoietin
level and hematological variables in wrestlers after intermittent
hypoxic exposure (IHE). Twelve wrestlers were assigned into two
groups: hypoxia (sports training combined with IHE, n=6) and
control (sports training, n=6). An IHE was performed for
10 days, with one day off after 6 days, once a day for about
an hour. The concentrations of hydrogen peroxide (H2O2),
nitric oxide (NO), vascular endothelial growth factor (VEGF)
and erythropoietin (EPO), as well as total creatine kinase
activity (CK) were measured. Also, the hematological markers
(Hb -hemoglobin, Ht - hematocrit, RBC - red blood cell, WBC -
white blood cell, Ret - reticulocytes) were analyzed. The 6-day
IHE caused an increase in the levels of H2O2, NO and VEGF.
Similarly, the EPO level and WBC count reached the highest value
after 6 days of IHE. The total Ret number increase constantly
during 10 days of IHE. The hypoxia group showed a higher CK
activity compared to the control. In conclusion, 10-day IHE in
combination with wrestling training elevates levels of H2O2, NO
and VEGF, and improves the oxygen transport capacity by the
release of EPO and Ret in circulation.