Principem transmisní radiografie je sledování změn ve vlastnostech svazku pronikavého záření, které prochází zkoumaným vzorkem. Tyto změněné vlastnosti jsou registrovány zobrazovacími detektory umístěnými zpravidla za zkoumaným vzorkem. Na základě zaznamenaných změn ve vlastnostech svazku je zpětně usuzováno na struturu či složení vzorku. Použití kvalitních zobrazovacích detektorů záření hraje v transmisní radiografii spolu s kvalitou svazku klíčovou roli. Vlastnosti současných polovodičových pixelových detektorů dnes již v mnoha ohledech předstihují tradiční zobrazovací prvky založené na analogové integraci náboje, např. CCD. Pixelové detektory umožňují s vysokou účinností, velkou snímací rychlostí a v podstatě neomezeným dynamickým rozsahem registrovat jednotlivé částice ionizujícího záření a rozlišit je podle energie., Jan Jakůbek, Jiří Dammer, Tomáš Holý, Michal Platkevič, Josef Uher, Zdeněk Vykydal., and Obsahuje bibliografii
Rozhovor se znamenitým astrofotografem a zakladatelem soutěže Česká astrofotografie měsíce Zdeňkem Bardonem o jeho zájmu o vesmír, výrobě prvního amatérského dalekohledu z babiččiných brýlí a zálibě v technice až po rekonstrukce světových teleskopů a špičkové astrofotografie, jež okouzlily nejen NASA. and Zdeněk Bardon, Jana Žďárská.
The author compares advantages and disadvantages of measures of positive discrimination and strategies of gender mainstreaming. At the beginning she describes the history of both measures and she focuses on their use for the purposes of gender equality. Whereas the author criticizes measures of positive discrimination on the basis of its stigmatizing and categorizing potential effect, she highlights the strategies of gender mainstreaming because of their neutral definitions and preventive character. In particular, she criticizes quotas that in her opinion add members of disadvantaged groups to the system without changing its systemic oppressive nature and thus stabilize institutional oppression. Nevertheless, she draws attention to a demerit of measures of gender mainstreaming as well. Namely she mentions the risk that gender mainstreaming would become measure for its own sake and that general use of these strategies would lead to ''gender oversaturation''.
In eukaryotic oxygenic photosynthetic organisms (both plants and algae), the maximum fluorescence is at peak P, with peak M lying much lower, or being even absent. Thus, the PSMT phase, where S is semisteady state, and T is terminal state, is replaced by a monotonous P→T fluorescence decay. In the present study, we found that dimethoate-treated wheat plant leaves showed SM transient, whereas in the case of control plants monotonous P→T fluorescence decay occured. We suggest that this was partly due to quenching of fluorescence due to [H+], responsible for P to S (T) decay in control plants (Briantais et al. 1979) being replaced by state transition (state 2 to state 1) in dimethoate-treated plants (Kaňa et al. 2012)., J. K. Pandey, R. Gopal., and Obsahuje bibliografii
In our study, the circadian blood pressure (BP) rhythm was studied in subjects with asymptomatic and normotensive pheochromocytoma. We have therefore performed 24-hour BP monitoring not only in 6 subjects with asymptomatic pheochromocytoma, but also in 33 patients with symptomatic pheochromocytoma and in 10 normotensive subjects, who served as a control group. Circadian BP rhythm was expressed by assessing a relative night-time BP decline. We found a similar BP rhythm, catecholamine excretion and tumor size in subjects with both forms of pheochromocytoma. Subjects with asymptomatic pheochromocytoma had a significantly lower night-time systolic BP decline (P=0.01) and diastolic BP decline (P=0.006) than normotensive controls. We conclude that the attenuated night-time BP decline in normotensive and asymptomatic subjects with pheochromocytoma might be a possible sign of partial desensitization of the cardiovascular system to catecholamines., T. Zelinka, J. Widimský, J. Weisserová., and Obsahuje bibliografii
The photosynthetic responses to elevated CO2 concentration (EC) at ambient and ambient +4°C temperature were aßsessed in the second leaf of rice (Oryza sativa L.) seedlings. The duration of different leaf developmental phases, as characterised by changes in photosynthetic pigment contents and photochemical potential, was protracted in the seedlings grown under EC. On the other hand, a temporal shift in the phases of development with an early onset of senescence was observed in the seedlings grown under EC at ambient +4°C temperature. The contents of carotenoids, ß-carotene, and xanthophyll cycle pigments revealed that EC downregulated the protective mechanism of photosynthetic apparatus against oxidative damages, whereas this mechanism assumed higher significance under EC at ambient +4°C temperature. We observed an enhancement in electron transport activity, photochemical potential, and net photosynthesis in spite of a loss in photostasis of photosynthesis under EC. On the other hand, the loss in photostasis of photosynthesis was exacerbated under EC at ambient +4°C temperature due to the decline in electron transport activity, photochemical potential, and net photosynthesis., S. Panigrahi, M. K. Pradhan, D. K. Panda, S. K. Panda, P. N. Joshi., and Seznam literatury