National Repository of Grey Literature 59 records found  beginprevious30 - 39nextend  jump to record: Search took 0.01 seconds. 
Vliv potravy kontaminované manganem na vývoj fytofágů
Šťasta, Michal
Foreign substances (including heavy metals) enter to the food chain of the animal part of ecosystem can affect the development of organism, its mortality rate and consumed food quantity. It is depended not only on the ability to elimination of these substances influence by the organisms. The effect of the diet with differentiated levels of manganese has been studied in laboratory conditions on caterpillars Cabera pusaria (Lepidoptera; Geometridae). Laboratory breading took place in Climacell chamber with controlled temperature, humidity, and lighting conditions. Three different contents of manganese in the diet of caterpillars was achieved by dipping of birch leaves (Betula pendula) in solutions of MnCl2.4H2O. We determined the statistical significant differences between the treatments in experiment in the amount of consumed food, the time of pupation, mortality rate of caterpillars. And significant differences were detected in unconsumed food, droppings and pupae. The increased concentration of manganese in the diet had a negative influence on the development of C. pusaria larvae and it can cause 100% mortality of caterpillars.
Determination of manganese in food supplements by atomic absorption spectrometry
Melicharová, Zuzana ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
EN The main content of this thesis was the determination of manganese in the form of manganese ions in food supplements by the atomic absorption spectrometry. It was necessary to find the optimum conditions for this method, to conduct interference studies, to find a suitable way of transferring samples into solution and to determin manganese to achieve this goal. Following parameters were examined in optimalization study: beam height above burner edge, burner horizontal position, acetylene flow rate, torch angle, and spectral interval width. Copper, iron, sodium and calcium ions were investigated as interferents as they were present at the highest concentration in selected food supplements. The conversion of solid samples into solution was carried out in water and nitric acid at a room temperature as well as elevated temperature. These food supplements were selected for analysis: Calibrum 50 Plus, Caltrate Plus, Center A to Iron, DAS Gesunde Plus A-Z Multispectrum, GS Extra Strong Multivitamin, Spectrum 50+ and Supradyn Energy Complex. The manganese assay was performed on a GBC 933 AA spectrophotometer. Standard solutions were measured to determine the detection limit and the limit of determination of the instrument. The detection limit was 0.001 mg/l and the limit of determination was 0.004 mg/l...
Reakce fytofágů na potravu ovlivněnou manganem
Šťasta, Michal
ntropogenní činnosti mohou vést ke zvýšeným koncentracím manganu v životním prostředí. Mangan patří mezi mikroelementy a je nezbytný pro metabolismus rostlin, avšak jeho vyšší koncentrace v rostlině mohou působit jako stresový faktor. Proto bylo cílem práce vymezit míru schopnosti některých fytofágů výběrem eliminovat manganem kontaminovanou potravu v terénních podmínkách a dále také vymezit reakci dospělců rodu Phyllobius na kontaminovanou potravu v laboratorních podmínkách. Reakce fytofágů na diferencovanou úroveň manganu byla šetřena ve fóliovnících umístěných v lesní školce Řečkovice. K sazenicím byl do půdního substrátu přidáván monohydrát síranu manganatého (MnSO4.H2O), tím vznikly tři varianty s diferencovanou úrovní manganu a varianta kontrolní s přirozenou koncentrací manganu. Experiment potvrdil, že fytofágní druhy preferovaly sazenice s nižším obsahem manganu v asimilačním aparátu. Sazenice reagovaly na zvýšené koncentrace manganu zpomaleným růstem.
Taxonomic position, phylogenetic relationships and metal resistance of green algae dominating in phytoplankton of two acid lakes
Barcyte, Dovile ; Nedbalová, Linda (advisor) ; Hašler, Petr (referee)
The aim of this diploma thesis was to reveal the taxonomic position and phylogenetic relationships of the dominant planktonic algae in two acid metal-rich lakes (Hromnice Lake and Plešné Lake, Czech Republic) and to compare these isolates with other closely related strains with the focus on the tolerance to various toxic metals (Cr, Al, Cu, Mn, Zn, Hg). The phylogenetic analyses showed that both strains belong to species Coccomyxa simplex. It was the first evidence that specifically this species is capable to become the dominant phytoplankton alga in the extreme environment of acid lakes with increased supply of phosphorus. Based on 18S rDNA analysis, four independent phylogenetic lineages were revealed within the genus Coccomyxa with three of them containing isolates from acid freshwaters. Furthermore, new strains of the recently described species Coccomyxa polymorpha were found growing in various chemical solutions. The toxicity test revealed that Coccomyxa simplex strains isolated from Hromnice and Plešné lakes did not show any peculiar resistance to increased metal concentrations. A significantly strain-specific response was recorded in case of aluminum, however, it was not related to the concentration of this metal in the original habitat. The ability to thrive in extreme habitats is probably...
Application of Atomic Absorption Spectrometry for Determination of Selected Elements from Potential Ecological Burden Area
Juránková, Lada ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This work is focused on the determination of selected (chemical) elements (Fe, Mn, Zn, Cr, Na, K, Mg a Ca) in a potential ecological burden area using flame atomic absorption spectrometry as a detection technique. A potential ecological burden is represented by tires which are used as a construction material or as an environment surrounding for growing decorative and consumable plants. Analytes were determined in plant origin samples. Firstly, the samples were dried in a laboratory electric dryer. The weighted amount of a dried sample (approximately 0.2 g) was digested inside a microwave decomposition device with an addition of nitric acid and hydrogen peroxide. An optimization of experimental parameters was done for each of the elements before sample measuring. A burner height was optimized and 8 mm height was chosen as a optimum for most elements. Under the optimum condition basic characteristics were measured for each element separately. These characteristics included limits of detection that were: 0.05; 0.01; 0.08; 0.21; 0.02; 0.01; 0.01; 0.01 mg L-1 for the following elements: Fe, Mn, Zn, Cr, K, Ca, Mg and Na, respectively. The limits of quantification, sensitivity and repeatability were determined for each element as well. A significant attention was paid to the content of zinc in the studied...
Determination of selenium and manganese in cerebrospinal fluid by atomic absorption spectrometry
Jiráková, Lucie ; Kotaška, Karel (advisor) ; Klapková, Eva (referee)
The aim of this study was to confirm the use of electrothermal atomic absorption spectrometry for the determination of selenium and manganese in the cerebrospinal fluid and to investigate concentrations of selenium and manganese in selected group of patients. For selenium was determined the detection limit 2,9 μg/l, for manganese 0,26 μg/l. 73 patients were examined (31 women, 42 men) whose average age was 14,1 years. The patients were divided into two groups according to age (56 children, 17 adults) and into two subgroups according to diagnoses (oncological, neurological). The control group consists of 18 subjects (5 women, 13 men, average age 21,7 years) with non-oncological and non-neurological diagnoses. We found significantly increased selenium concentrations in cerebrospinal fluid in the control group, compared with the group with neurological diagnoses (median = 14,4 μg/l vs. 12,4 μg/l, p < 0.05). Elevated levels of manganese in cerebrospinal fluid was observed in a group of children with oncological diseases compared with control group (1,2 μg/l vs. 0,5 μg/l, p < 0.05). Determination of selenium and manganese in the cerebrospinal fluid may have diagnostic importance in selected groups of patients. Powered by TCPDF (www.tcpdf.org)
Cross-bridged cyclams as manganese(II) chelators
Míka, Luděk ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Title: Cross-bridged cyclams as manganese(II) chelators Autor: Bc. Luděk Míka Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: doc. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail address: modrej@natur.cuni.cz Abstract: The aim of this project was to synthesize a new kind of Mn(II) complexes with ligands derived from cross-bridged cyclam. These complexes may be potentially used as contrast agents in magnetic resonance imaging. Six macrobicyclic ligands with various pendant arm were synthesized, three complexes were sucesfully prepared. Electrochemical properties of prepared manganese(II) complexes with synthesized ligands were studied using cyclic voltammetry. Relaxivity of prepared complexes was determined by 1 H NMR spectroscopy. Keywords: cross-bridged cyclam, phosphonate, phosphinate, pendant arms, manganese
Design and synthesis of selective manganese(II) chelators
Míka, Luděk ; Kotek, Jan (advisor) ; Tauchman, Jiří (referee)
Title: Design and synthesis of selective manganese(II) chelators Autor: Luděk Míka Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: doc. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail address: modrej@natur.cuni.cz Abstract:Abstract:Abstract:Abstract: The aim of this project is to synthetize new kind of macrobicyclic ligands derived from cross-bridged cyclam for complexation of Mn2+ ions. These complexes may be potentially used as contrast agents in magnetic resonance imaging. Three macrobicyclic ligand with various pendant arms were synthesized. The ability to complex manganese(II) ions were studied by Mass Spectroscopy. Electrochemical properties of manganese(II) complexes with general chelating agents and one synthesized ligand were studied using cyclic voltammetry. Keywords:Keywords:Keywords:Keywords: cross-bridged cyclam, phosphonate, phosphinate, pendant arms, manganese
Vliv zinku a manganu na zdraví a užitkovost hospodářských zvířat
Půlpánová, Barbora
This thesis focuses on charateristics of zinc and manganese in relation to performan-ce of livestock. The general significance of all the minerals in livestock's nutrition is summarized in this thesis. In this thesis, there is description of micro and macro elements and its effect on metabolism of organisms. The effect of the essential values of manga-nese and zinc to different species of livestock and possible consequences on its health and performance due to deficiency or overdose of minerals in food is described. In this thesis the author also deals with differences between organic and inorganic forms of zinc and manganese, their fitness for each category and effect on economy of lives-tock and enviroment. Manganese and zinc are irreplaceable suplements in the fertility and immunity of an or-ganism. In reproduction they help with regular and quality estrus in females. In males they have positive effect on quality and vitality of semen in the ejaculate. In the immune system the zinc and mangan play an important role mainly in antioxidative pro-cesses. Both elements are part of superoxiddismutase which is one of the enzymes that helps eliminate free radicals from the body. Manganese also participates in intracellular matter, cartilage and bone development.
Improvement of Manganese Separation in Drinking Water Treatment
Bartoš, Ladislav ; Janda, Václav (referee) ; Hlaváč, Jaroslav (referee) ; Dolejš, Petr (advisor)
The submitted paper covers manganese comprehensively. The introduction provides an overview of its basic physical and chemical properties. Its compounds are discussed individually, including their preparation, production, and practical uses. Furthermore, a list of analytical methods in which manganese is involved in the form of its compounds as reagents is included. The same section includes an overview of analytical methods whereby manganese and its compounds are detected, primarily in water industry processes. Attention is paid to manganese as a non-negligible constituent of the various parts of the environment. The section on manganese’s biogenic properties is interesting from the viewpoint of its toxicity as well as its role as an important biogenic element, indispensable primarily for mammals. The subsequent chapters discuss the various methods which are suitable, under specific conditions, for separation in the treatment of surface and underground water aimed at producing drinking, process, or industrial water, where a minimal concentration of this metal is required. The impact of the physical/chemical conditions which influence the efficiency of separation in a manner ranging from non-negligible to principal, is discussed further on. Given the specifics of treatment of surface [and] underground water, the chapters provide more details on the processes suitable for specific types of matrix and specific conditions. Next chapters sum up many years of the author’s observations and experiences in the various parts of the water management system, from the raw water source to treatment to distribution, focusing on surface and underground water separately. Last chapter describes the construction of a water treatment plant model, its launch and calibration, and the tests focused on separating manganese by way of coagulation using aluminium and iron sulphate.

National Repository of Grey Literature : 59 records found   beginprevious30 - 39nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.