National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Enzymatic modifications of bioactive flavonoids
Rydlová, Lenka ; Tesařová, Eva (advisor) ; Wimmer, Zdeněk (referee)
Extract from milk thistle (Silybum marianum (L.) Gaertn., synonym Carduus marianus L., Asteraceae) silymarin contains among others primarily bioactive flavonolignans. They have hepatoprotective and antioxidative effects and also anticancer, chemoprotective, dermatoprotective and hypocholesterolemic activity. This thesis focuses on the preparation of metabolites of the second phase of biotransformation unexplored flavonolignans 2,3-dehydrosilybin (DHSB), silychristin (SCH), 2,3-dehydrosilychristin (DHSCH). Pure sulfated derivatives were prepared using aryl sulfotransferase from Desulfitobacterium hafniense and p-nitrophenyl sulfate (p- NPS) as a donor. Flavonolignans yield exclusively monosulfates at the position C- 20 (C-19 in the case of silychristin and 2,3-dehydrosilychristin), except for 2,3- dehydrosilybin that gives also the 7,20-disulfated derivatives. For all samples were made antioxidant tests - DPPH assay (the highest activity had 2,3-dehydrosilychristin sulfate: IC50= 7,87 µM), Folin-Ciocalteau reduction assay (the highest activity had 2,3-dehydrosilychristin: 1,58 ekvivalents of gallic acid), ABTS+ scavenging (the highest activity had silychristin: 1,50 ekvivalents of vitamin C), inhibition of microsomal lipid peroxidation (the highest activity had 2,3-dehydrosilybin: IC50 = 10,6 µM),...
Determination of selected elements in plant extracts by atomic absorption spectrometry
Rydlová, Lenka ; Hraníček, Jakub (advisor) ; Kratzer, Jan (referee)
The aim of this bachelor thesis was to determine selected elements (Na, Mg, K, Ca, Zn, Se) in plant extracts and juices by atomic absorption spectrometry using different types of atomization. Each method has been optimized for determination of the mentioned elements. For flame atomization it has been used optimization of height of the primary radiation from the hollow cathode lamp over the edge of the burner. The height was generally between 6.0 and 8.0 mm. Then there have been optimized flow of each component of the flame (acetylene, air, nitrous oxide) and it has been set location of the hollow cathode lamp and the flame. Under the optimized conditions basic characteristics describing the method of the determination of mentioned elements have been measured (LOD for sodium 2.13 µg L-1 , for magnesium 2.44 µg L-1 , for potassium 11.3 µg L-1 , for calcium 15.6 µg L-1 , for zinc 6.04 µg L-1 , for selenium 0.34 µg L-1 ). In the next part of the thesis the optimized methods have been used for measuring concentration of all elements in real samples. After the preparation of the samples including dilution, addition of various reagents etc., they have been atomized by flame in an atomic absorption spectrometer (Na, Mg, K, Ca, Zn) and determined, or converted to a volatile compound (Se) and determined by...
Function of verb paradigms of "hablara" a "hablase" in Present-Day Spanish
Rýdlová, Lenka ; Čermák, Petr (advisor) ; Krinková, Zuzana (referee)
This theses is dedicated to the use of the verbal paradigms hablara and hablase in contemporary Spanish. We demonstrate that due to historical reasons the usage of paradigm hablara is much wider than that of hablase, which can be used only in the subjunctive meaning. According to the valid linguistic norm, the paradigm hablara (and not hablase) can be used instead of the Past Perfect (although it is not recommended). The same is evidenced with the conditional tense of the modal verbs querer, deber and poder as well as with the main clause of the unreal conditional clauses in the present tense. This means that these two verb paradigms can be arbitralily substituted only when used in the subjunctive function. On the basis of our own frecuency analysis of twenty most used Spanish verbs in the language corpus CREA, we prove that the frecuency of the hablase on average 18% in Spain and 10% in Latin America. Our analysis of this corpus material does not confirm the statement of some linguists that the frecuency of -se form is generally slightly higher in negative sentences. However, our analysis of a parallel corpus InterCorp seems to indicate that it is higher (by 7%) after the conditional conjunction ‚si'.
History of the Spanish language norm and its codification
Rýdlová, Lenka ; Čermák, Petr (advisor) ; Zavadil, Bohumil (referee)
This dessertation shows basic characteristics of Spanish language norm and its development during more than five centuries. Spanish norm is also confronted with the Czech context. In the first chapter we pointed out the polycentric character of Spanish language norm, which is caused by a big amount of native speakers spread in three continets. This type of norm is common for languages that exceed borders of one country. Literary Spanish unites all Spanish native speakers, it is unders-tood by all of them, it is a language of literature, mass media and for-mal locution, and this language is studied in codification manuals. Li-terary Czech is also uniform all over the Czech Republic, but is not used at all in common conversation, in which unambigously dominates popular (vulgar) language. Popular Czech is nowadays spread more or less all over the country, therefore in the Czech kontext there are two national languages: literary Czech and popular Czech. On the contrary, Spanish popular language is very limited, which is also caused by the activity of mass media that spread literary language. We can see that in Spanish context the situation is completely contradictory: literary Spanish influences popular Spanish, not vice versa like in the Czech context. We proceeded with a short summary of Spanish grammatical...
A Randomized Heuristic for the Capacitated Postman Problem
Rýdlová, Lenka ; Pelikán, Jan (advisor) ; Fesenko, Anastasiya (referee)
Graph theory is a large mathematical discipline. Chinese postman problem falls under category of arc vehicle routing problems. Chinese postman problems are very extensive and difficult to calculate in practice. They belong to NP-hard problems. For this reason, heuristics are proposed to provide acceptably good solution in polynomial time. The focus of this thesis is to propose a randomized heuristic which does not follow deterministic rules but is ruled by random. Monte Carlo simulation is launched to find the best solution. Heuristic is formulated for undirected capacitated rural postman problem. It is programmed in VBA and validated on testing problems. At the end of the thesis is a case study about municipal garbage collection.
Comparison of professional optimization systems performance
Rýdlová, Lenka ; Jablonský, Josef (advisor) ; Charvát, Karel (referee)
The problems of linear programming are very extensive in practice and professional optimization systems are necessary to their solution. Most of the time, these problems concern mixed integer programming. These types of problems have to be solved other then simplex method, even if the other methods are based on it. Integer conditions cause high difficulty with solving and disproportionately prolong solution time. These problems can be found in an electronically library MIPLIB. The library is used to testing optimization systems, which are whole range. The best programs on the market are CPLEX, Gurobi, Xpress and LINGO, used at our university. The focus of this thesis is testing the performance of each program listed above. The comparison is done based on solution time and accuracy of the calculated optimal solution.

See also: similar author names
2 Rydlová, Lucie
1 Rýdlová, Lada
6 Rýdlová, Lenka
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