Laser-induced breakdown spectroscopy (LIBS) is currently a progressively developing technique providing fast and flexible elemental analysis of various types of materials. For applications, which demand to determine of C, S or P, a detection of vacuum ultraviolet (VUV) radiation is required. Analysis of ferrous alloys is among them. Article describes the design of the VUV module for the interaction chamber of the LIBS setup in Laboratory of Laser Spectroscopy, Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology. Results of the LIBS analysis of carbon detection in low-alloyed steel samples is presented. and Spektroskopie laserem buzeného plazmatu (LIBS - z anglického Laser-Induced Breakdown Spectroscopy) je v současnosti dynamicky se rozvíjející metoda, poskytující rychlou a flexibilní prvkovou analýzu mnoha různých typů materiálů. Pro aplikace vyžadující stanovení prvků, jako jsou C, S, P, je nutno využít detekci záření v hluboké ultrafialové oblasti (VUV). Mezi tyto aplikace patří i analýza železných slitin. Článek popisuje konstrukci VUV modulu pro interakční komoru aparatury LIBS v Laboratoři laserové spektroskopie na Ústavu fyzikálního inženýrství (ÚFI) Fakulty strojního inženýrství (FSI) Vysokého učení technického v Brně (VUT). Prezentovány jsou výsledky LIBS analýzy využitím VUV modulu na příkladu analýzy uhlíku v nízkolegovaných ocelích.
We prove that every modular function on a multilattice $L$ with values in a topological Abelian group generates a uniformity on $L$ which makes the multilattice operations uniformly continuous with respect to the exponential uniformity on the power set of $L$.
Chlorophyll fluorescence measurements showed that plasticity to salinity in stems of Salicornia ramosissima is expressed at a modular level, so intraplant variation should be considered in further studies. and S. Redondo-Gómez ... [et al.].
Determination of modulated chlorophyll fluorescence coupled to measurements of the net photosynthetic rate (P^) leaf water potential has heen assessed as a screening method to score a set of twenty genotypes of barley {Hordeum vulgare L.) for drought tolerance. These methods can be ušed as rapid screening tests for water stress tolerance in barley, although applied alone they are appropriate indicators for a severe water stress. For genotypes growing under a mild water stress, it is necessary to use several screening tests simultaneously. Drought tolerant genotypes show smaller variations of photochemical quenching, P^, water use efficiency and leaf temperature than the drought sensitive ones.
Current research on the effect of increased UV-B radiation on crop production has been limited to exposing plants to improbable UV-B dose or growth condition. The objective of this study was to test the effects of short-term modulated increased UV-B radiation on maize (Zea mays L.) growth, grain yield, and quality under field conditions for three years. A modulated irradiance system was used to maintain UV-B radiation at 30% above the ambient level and was applied daily between the elongation and silking stages of maize. The result indicated that increased UV-B radiation adversely affected maize growth and yield, especially on plant height when UV-B was enhanced at the elongation stage and on yield when UV-B was enhanced near the silking stage. Yield reduction that induced by enhanced UV-B radiation was associated with reductions in number of kernels per row and kernel mass. Protein content of grains was increased with enhanced UV-B radiation, but oil and starch contents were not affected. This study confirmed the sensitivity of maize to increased UV-B radiation under the field condition, and contributed to understand the full negative and positive effects of increased UV-B radiation on crop production., L. N. Yin, S. W. Wang., and Obsahuje bibliografii
Feeding K+ or Na+ nitrate salts in vivo enhanced the activity of phosphoenolpyruvate carboxylase (PEPC) in the leaf extracts of Alternanthera pungens (C4 plant) and A. sessilis (C3 species). The increase was more pronounced in A. pungens than in A. sessilis. Chloride salts increased the PEPC activity only marginally. However, the sulfate salts were either not effective or inhibitory. Feeding nitrate modulated the regulatory properties of PEPC in A. pungens, resulting in increased KI (malate) and decreased KA (glucose-6-P). The sensitivity of PEPC to malate, which gives a measure of phosphorylation status of the enzyme, indicated that feeding leaves with NO3- enhanced the phosphorylation status of the enzyme. The reduction in PEPC activity due to cycloheximide treatment suggested that increased synthesis of PEPC protein kinase may be one of the reasons for the enhancement in PEPC activity, after the nitrate feeding. We suggest that nitrate salts could be used as a tool to modulate and analyze the properties of PEPC in C3 and C4 plants. and A. V. Rajagopalan, R. M. Agarwal, A. S. Raghavendra.
Taking into consideration the biological importance of interaction between antioxidant defense (AD) enzymes and sexual steroid hormones it was deemed important to compare our recent achievements in the field with the state of current knowledge. The main goal of the present review was to investigate the changes of AD enzyme activities: superoxide dismutases, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase in the brain of female and male rats depending on progesterone and estradiol. These ovarian steroids produce their effects by acting on numerous target tissues and organs, such as the reproductive organs, bone tissue and cartilage, peripheral blood vessels and the central nervous system (CNS). We have chosen it as a new parameter that might represent an important indicator of the changes within the CNS, bearing in mind the biological importance of the enzymes of the AD system. Our experimental results indicate that the AD enzyme activities in the brain tissue of female and male rats show a certain dependence on the concentration of progesterone and estradiol. The present review suggests that the modulation of the oxidative and antioxidative capacity by sexual steroid hormones is mediated through antioxidant metabolizing enzymes., S. B. Pajović, Z. S. Saičić., and Obsahuje bibliografii a bibliografické odkazy
Baroreflex sensitivity (BRS) is abnormal in the prediabetic state. This study was conducted to determine effects of chronic rosiglitazone (RSG), an insulin sensitizer, on BRS in prediabetic hyperglycemic (PDH) rats induced by nicotinamide and streptozotocin. The fasting and postprandial blood glucose levels were 5.6–6.9 and 7.8–11.0 mmol/l, respectively. Rats were treated with RSG or saline for 12 weeks. BRS response to phenylephrine (PE-BRS) or sodium nitroprusside (NP-BRS) was determined by linear regression method. Cardiac sympathetic and parasympathetic influences were determined by autonomic blockades. In the saline-treated PDH rats, PE-BRS was enhanced early at week 4 and became greater at week 12. Abnormalities in NP-BRS and cardiac autonomic influences were found only after week 12. Four weeks of RSG treatment normalized blood glucose levels but not PE-BRS. All altered cardiovascular variables were completely restored by 12 weeks of RSG treatment. The correlation between BRS and blood glucose levels in salinetreated PDH rats was significant at week 12, but no correlation was found in RSG-treated rats. In conclusion, hyperglycemia, even in the prediabetic state, may play a role in BRS abnormalities. RSG treatment early in the prediabetic state may normalize BRS via cardiac autonomic modulation, besides its antihyperglycemic action., L.-Z. Hong ... [et al.]., and Obsahuje seznam literatury
Previous data suggest that type 1 diabetes mellitus leads to the deterioration of myocardial intercellular communication mediated by connexin-43 (Cx43) channels. We therefore aimed to explore Cx43, PKC signaling and ultrastructure in non -treated and omega-3 fatty acid (omega-3) treated spontaneously diabetic Goto-Kakizaki (GK) rats considered as type 2 diabetes model. Four-week-old GK and non-diabetic Wistar-Clea rats were fed omega -3 (200 mg/kg/day) for 2 months and compared with untreated rats. Realtime PCR and immunoblotting were performed to determine Cx43, PKC- epsilon and PKC-delta expression. In situ Cx43 was examined by immunohistochemistry and subcellular alterations by electr on microscopy. Omega-3 intake reduced blood glucose, triglycerides, and cholesterol in diabetic rats and this was associated with improved integrity of cardiomyocytes and capillaries in the heart. Myocardial Cx43 mRNA and protein levels were higher in diab etic versus non- diabetic rats and were further enhanced by omega-3. The ratio of phosphorylated (functional) to non-phosphorylated Cx43 was lower in diabetic compared to non- diabetic rats but was increased by omega-3, in part due to up -regulation of PKC-epsilon. In addition, proapoptotic PKC-delta expression was decreased. In conclusion, spontaneously diabetic rats at an early stage of disease benefit from omega-3 intake due to its hypoglycemic effect, upregulation of myocardial Cx43, and preservation of cardiovascular ultrastructure. These findings indicates that supplementation of omega-3 may be beneficial also in the management of diabetes in humans., J. Radosinska, L. H. Kurahara, K. Hiraishi, C. Viczenczova, T. Egan Benova, B. Szeiffova Bacova, V: Dosenko, J. Navarova, B. Obsitnik, I. Imanaga, T. Soukup, N. Tribulova., and Obsahuje bibliografii
We studied the effects of GABA receptor agonists microinjections
in medullary raphé on the mechanically induced tracheobronchial
cough response in anesthetized, unparalyzed, spontaneously
breathing cats. The results suggest that GABA-ergic inhibition
significantly contributes to the regulation of cough reflex by
action of both GABAA and GABAB receptors. The data are
consistent with inhomogeneous occurrence of GABA-ergic
neurons in medullary raphé and their different involvement in the
cough reflex control. Cells within rostral nucleus raphé obscurus
with dominant role of GABAA receptors and neurons of rostral
nucleus raphé pallidus and caudal nucleus raphé magnus with
dominant role of GABAB receptors participate in regulation of
cough expiratory efforts. These cough control elements are
distinct from cough gating mechanism. GABA-ergic inhibition in
the raphé caudal to obex had insignificant effect on cough.
Contradictory findings for GABA, muscimol and baclofen
administration in medullary raphé suggest involvement of
coordinated activity of GABA on multiple receptors affecting
raphé neurons and/or the local neuronal circuits in the raphé
modulating cough motor drive.