The article describes automation of 2-dimensional surface analysis in the aparature for laser spectroscopy (LIBS). Such analysis give us 2D map of presented chemical elements. The main part is dedicated to algorithm choosing suitable for evaluation of the image sharpness. Digital camera and ablation laser share the same focusing optics, so knowing the exact image sharpness it is possible to set sample object to focal plane. There are theoretically described and experimentaly tested different kinds of methods how to obtain a relative sharpness number: gradient based method and methods working in frequency domain. Digital noise phenomenon is also discussed. As an output a selection of suitable method has been made with respect to its speed, accuracy and durability against digital noise. and Článek popisuje řešení automatizace dvourozměrné povrchové analýzy v zařízení pro laserovou spektroskopii (LIBS), jejímž výsledkem je 2D mapa přítomnosti chemických prvků. Hlavní část je věnována výběru algoritmu pro opětovné nastavení mapovaného vzorku do ohniskové roviny objektivu, který zároveň slouží k fokusaci laserového svazku. Děje se tak pomocí analýzy ostrosti snímku vzorku. Teoreticky jsou rozebrány a experimentálně otestovány různé metody vyhodno cení ostrosti snímku, a to metoda gradientní a metody pracující s frekvenčním spektrem obrazu. Článek se zabývá také problematikou filtrace digitálního šumu. Výstupem je volba vhodného algoritmu s ohledem na rychlost, přesnost a odolnost vůči digitálnímu šumu.
Alkali stress is an important agricultural problem that affects plant metabolism, specifically root physiology. In this study, using two rice cultivars differing in alkali resistance, we investigated the physiological and molecular responses of rice plants to alkali stress. Compared to the alkali-sensitive cultivar (SC), the alkali-tolerant cultivar (TC) maintained higher photosynthesis and root system activity under alkali stress. Correspondingly, the Na+ content in its shoots was much lower, and the contents of mineral ions (e.g., K+, NO3-, and H2PO4-) in its roots was higher than those of the SC. These data showed that the metabolic regulation of roots might play a central role in rice alkali tolerance. Gene expression differences between the cultivars were much greater in roots than in shoots. In roots, 46.5% (20 of 43) of selected genes indicated over fivefold expression differences between cultivars under alkali stress. The TC had higher root system activity that might protect shoots from Na+ injury and maintain normal metabolic processes. During adaptation of TC to alkali stress, OsSOS1 (salt overly sensitive protein 1) may mediate Na+ exclusion from shoots or roots. Under alkali stress, SC could accumulate Na+ up to toxic concentrations due to relatively low expression of OsSOS1 in shoots. It possibly harmed chloroplasts and influenced photorespiration processes, thus reducing NH4+ production from photorespiration. Under alkali stress, TC was able to maintain normal nitrogen metabolism, which might be important for resisting alkali stress., H. Wang, X. Lin, S. Cao, Z. Wu., and Obsahuje bibliografii
In the present work neonatal male and female Wistar rats were treated intraperitoneally with monosodium glutamate (MSG 2 mg/kg b.w.) or saline (controls) daily for 4 day after birth. At the age of 30 and 80 days, the alkaline phosphatase activity (AP) in the brush border of individual enterocytes, the body fat content and Lee´s index of obesity were analyzed. Microdensitometrical quantification of AP was significantly increased on day 30 in males (P<0.01) and on day 80 in MSG-treated male and female rats (P<0.001) as compared to the controls. MSG administration also increased the body fat weight and the obesity index significantly (P<0.001) in 80-day-old animals, but was without any significant effect on their food intake. Our results showed that a) neonatal MSG-treatment may significantly change the intestinal function and b) the investigation of the intestinal enzyme activities may be important in further studies on MSG-induced and other forms of obesity., Š. Mozeš, Ľ. Lenhardt, A. Martinková., and Obsahuje bibliografii
The polymorphisms of the tumor suppressor gene p53 in exon 4 (p53 BstUI) and in intron 6 (p53 MspI) have been suggested to be associated with the genetically determined susceptibility in diverse types of human cancer. In our hospital-based case-control study, we examined the allele and genotype incidence of these polymorphisms as well as their haplotype combinations in 60 brain tumor patients (27 males and 33 females) and 183 controls without malignancies. The genotype characteristics were determined by the PCR-based RFLP method using DNA extracted from peripheral blood. In this study we show that the p53 BstUI and the p53 MspI polymorphisms are not associated with increased risk of brain tumors. Thus, we conclude that the p53 BstUI and the p53 MspI polymorphic sites within the tumor suppressor gene p53 do not represent genetic determinants of susceptibility to brain tumors., E. Biroš, I. Kalina, A. Kohút, E. Bogyiová, J. Šalagovič, I. Šulla., and Obsahuje bibliografii