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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Efekt polynenasycených mastných kyselin n-3 ve výživě potkana na expresi vybraného genu

Zamazalová, Nikola January 2015 (has links)
The aim of my thesis on topic The effect of n-3 polyunsaturated fatty acids in the diet of rats on expression of selected genes was to investigate the effect of eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) on the expression of genes which encode GPR120, AdipoR1 and AdipoR2 receptors in relation to suppress low-grade chronic inflammation in organism to reduce the risk of atherosclerosis by dietary intervention in rats. Rats were fed by a mixture MYPO with 6 % safflower oil (diet S), 6 % fish oil (diet F) or 6 % of oil from algae Schizochytrium (diet A). Gene expression was measured by quantitative real-time PCR method and the results were evaluated by using the software qbase + (Biogazelle NV). Relative expression of GPR120 gene was in F diet 88 % (P > 0,05), in A diet 93 % (P > 0,05) in comparison with control group (100 %). Relative expression of ADIPOR1 gene was in F diets and A diet 82 % (P < 0,05) in comparison with the control group. For ADIPOR2 gene relative expression was 71 % (P < 0,05) in diet F and 68 % (P < 0,05) in diet A. The results were contrary to our hypothesis. However, they exactly match the results of other studies in the available literature. It would be appropriate to carry out further studies on this issue.
32

Možnosti elektrochemické analýzy s využitím soustavy více elektrod s nespecifickou odezvou / Possibilities of Electrochemical Analysis Using a System of Electrodes With Non-Specific Response

Ederer, Jakub January 2014 (has links)
The master thesis present the possibilities of processing of electrochemical data from a group of four electrodes with non-selective response (simple sensor array) for electrochemical analysis with potential application of the results achieved in the construction of the sensor field type "electronic tongue". This simple system was applied to the sample simulating the food product. Electrochemical data were processed through mathematical operations such as Gaussian approximation, deconvolution or using basic mathematical operations.
33

Použití nasycených vyšších mastných kyselin v technologii vína

Chvalinová, Klára January 2017 (has links)
Sulfur dioxide has been used in the wine industry for many centuries due to its antimicrobial and antioxidant effects. However, the problem is that SO2 is a major allergen and when consuming higher doses, health complications (such as headaches, stomach aches, asthmatic problems) may occur. It is therefore important to find a suitable substitute, or rather a supplement to this substance. One of the options is the use of saturated higher fatty acids (HFA). These substances naturally occur in nature and a small amount of them is formed by yeasts themselves during fermentation. Thanks to HFA the yeast cells´ lipid membranes are changed (their liquidity), resulting in cell degradation, slowing of metabolism and thus slowing down the fermentation until it is stopped. In this experiment, a mixture of HFA, octanoic, decanoic and dodecanoic acid, ratio 2:7:1, respectively, was used at doses of 5, 10, 20, 30, 40 and 60 mg/l, with two variants of the application SO2, 20 mg/l or 40 mg/l. The HFA residues, the corresponding ethyl esters and the influence on sensory properties of the wine were observed. The results of this experiment show (or HFA residues) that the more HFA is added, the more they are absorbed by the yeasts. At the same time there was a very slow esterification in time and thus a low influence on the aroma of wine. Sensory analysis showed the HFA dose of 20 mg/l as the limit from which we are able to recognize differences in HFA doses. There was also an influence of sludge particles. The longer the wine matures, the less sludge particles it contains, hence the HFA are bound on the yeast cells, and thereby their influence on wine sensory is reduced.
34

Syntéza antimikrobiálních látek na bázi derivátů salicylové kyseliny / Synthesis of antimicrobial compounds based on derivatives of salicylic acid

Tvrdý, Václav January 2016 (has links)
Schiff bases are widely used both in technical practice and in the field of medicine. For their antimicrobial activities are studied as potential antimacterial and abtifungal drugs. With increasing level of resistence to currently drugs is the development of new substances very intense. Salicylanilides are a group of substances with antimicrobial activity and are also intensively studied. Based on that we were synthesized novel Schiff bases resulting from salicylic acid, respectively salicylanilides. It was concretely prepared five compounds: 5- chloro-N-{4-[phenyl(phenylimino)methyl]phenyl}-2-hydroxybenzamide, 5-bromo-N-{4-[ phenyl(phenylimino)methyl]phenyl}-2-hydroxybenzamide, 5-chloro-N-{4-[phenyl(3- chlorfenylimino)methyl]phenyl}-2-hydroxybenzamide, 5-chloro-N-{4-[phenyl(4- chlorfenylimino)methyl]phenyl}-2-hydroxybenzamide, 5-bromo-N-{4-[phenyl(4- chlorfenylimino)methyl]phenyl}-2-hydroxybenzamide. The reaction proceeded at the boiling point of the solvent, with catalytic amount of p-toluensulfonic acid. Most of the compounds were characterized by IR, H1 NMR, C13 NMR and melting point. The prepared compounds showed E/Z isomers on double bond, it is demonstrated on NMR specters.
35

Porovnání přípravků k zajištění koloidní stability bílých vín před lahvováním

Polehňa, Jan January 2014 (has links)
The thesis on comparing products to ensure the colloidal stability of white wines before bottling in the theoretical part examined the definition of colloid division of disperse systems and their relation to wine. Further described is the main cataracts occurring in wines and methods to prevent them, focusing on the practice of the most commonly used products: Metatartaric acid, gum arabic and carboxymethylcellulose (CMC). In the practical part of these products in different variations, combinations and concentrations added to white wine, which was a non-stabilized against the tartar and proteins. This wine was in the wake of bottling and variants of the same stored for one year in two different storage temperatures. In the course of storage was observed formation of cataracts in individual bottles. After a year all variants were opened and evaluated was total sensory analysis with qualification and quantification of turbidity, sediment filtration and weighing, measuring conductivity and pH. The results were statistically processed and evaluated with recommendations for practice.
36

Vliv kyseliny askorbové na senzorické a analytické parametry bílých vín

Smrčka, Jakub January 2015 (has links)
This thesis was focused on the effect of ascorbic acid on sensory and analytical parameters of white wine during production technology. The theoretical part is devoted to a detailed description of the mechanisms of oxidation of ascorbic acid and ultimate degradation products of ascorbic acid. In the theoretical part are also given basic methods for the determination of ascorbic acid. Another part focuses on the synergy of ascorbic acid and one of the most important substances in the manufacture of wine, sul-fur dioxide. The practical part includes an attempt was founded in 2014. The study compared different doses of ascorbic acid and sulfur dioxide have been added to the mash two varieties, Riesling and Grüner Veltliner. Attempt monitors antioxidant properties of ascorbic acid and its influence on the analytical and sensory component of the resulting wines. Based on the results, we can conclude that ascorbic acid has antioxidant capabilities asking if it was properly supplemented with sulfur dioxide.
37

Hodnocení kvality jablek v závislosti na podmínkách jejich pěstování / Evaluation of selected qualitative parameters of apples produced under different growing methods

Dresslerová, Ivona January 2016 (has links)
The most spread system of agricultural production is conventional system, which reaches the best profits by its excessive inputs into production such as fertilization, chemical spraying, heavy engineering. However the importance of ecological (BIO) and integrated (I.P.) production has been increasing among the consumers recently. Mainly because of environmental sustainability and protection of their own health. The aim of this study is to compare qualitative characteristics of 10 different apple cultivars (Melodie, Šampion, Gloster, Idared, Angold, Topaz, Goldstar, Ontario, Florina, and Rubín) with reference to the type of production system. The dry matter content, amount, concentration of carbohydrates, ascorbic acid, sensory evaluation and overall profile of volatile compounds were analysed in apples coming from both ecological and integrated agriculture. The dry matter content of all apple cultivars was measured by using two different methods. At the same time drying in an infra-red scale and refract metrical measuring by a portable refractometer were carried out. Concentrations of different carbohydrates (sucrose, glucose and fructose) were analysed by HPLC method with RI detection. The content of ascorbic acid (AA) was determined by HPLC with UV/VIS detection. During the sensory evaluations a protocol for a trained sensory panel was created including profile, pair and pair preference test. With an aim of detection of volatile aromatic compounds´ profile there was a sorption prepared on SPME extraction with following analysis on GC-GC-MS. In the concentration of C vitamin was the cultivar found statistically significant (p = 0,0004) and not in the supposed type of production. The final concentration of ascorbic acid was 13-130 mg/kg in BIO apples and 10-103 mg/kg in apples from integrated production. Overall 7 BIO cultivars had higher content of AA in comparison to I.P. The highest concentration of AA was in cultivar Ontario. In total 7 BIO cultivars from 10 had bigger content of AA in addition to integrated samples. The most present carbohydrate in apples is fructose in which was found a statistically significant difference between values of BIO and I.P. (p = 0,0272). The highest figure of fructose and also of sum of sugars was Angold BIO (422,3 g/kg). The highest presence of dry matter was found in cultivar Florina BIO (18,62 %). Refract metrical matter was in the range from 11 to 17 Brix. There was a statistically significant importance proved between the figures of BIO and I.P between both dry matters. At the same time it was proved that there is present a dependence between them based on correlation coefficient (r = 0,9622). It was assumed that the overall sum would correlate with refract metrical dry matter, but this was not confirmed. There was also proved a statistical difference (p = 0,0002) between the BIO and I.P apple weights. In all cases of samples the weights of I.P apples was higher. In sensory analysis the cultivar Šampion BIO was evaluated the best from the overall intensity and pleasure of the taste. Topaz I.P was evaluated as the sample with the most pleasant taste and Florina I.P with the highest taste intensity. By the analysis of pair preference test results it was confirmed that there is a statistically significant difference on the selected level of probability 99%. But preference in any of production systems was not confirmed. During the analysis of overall profile of volatile aromatic substances it was found out that the same cultivar of different production has the same composition, but different relative concentration of the present substances. This problematics needs further and more detailed analysis, which would prove or disprove influence of the cultivar on all analysed aspects.
38

Faktory ovlivňující průběh odstraňování dusíkatého znečištění z odpadních vod specifického složení / Factors affecting the nitrogen compounds removal process in specific types of wastewater

Radechovský, Josef January 2016 (has links)
Abstract: This work summarizes the current knowledge about removing of nitrogen compounds from wastewater using non-traditional biological methods. They include for example process of nitritation/denitritation and a process of deammonification. Special innovative biological methods are economically advantageous because of savings of oxygen for the oxidation of N-ammon and organic substrate for the formation of N2. Achieving of accumulation of nitrites (achieving of shortcut nitrification) due to suppression of nitrite oxidising bacteria (NOB) is the basis of methods mentioned above. Stable shortcut nitrification is influenced by many factors and achieving of this process in a low-strength wastewater is still problematic, so some new procedures how to optimize it are investigated. This was also the main aim of research that was realized at the Department of Agroenvironmental Chemistry and Plant Nutrition of the Czech university of Life Sciences in Prague.
39

Vliv stresových faktorů na růst intaktních rostlin podnoží révy vinné in vitro

Dvořáková, Vladimíra January 2016 (has links)
This thesis deals with the effects of water scarcity and excess lime in the soil to grow rooted grapevine rootstocks. The theoretical part provides summary information on the structure and main functions of the root system with increased attention on the production of phytohormones. The following chapter discusses the physiology of stress in plants, focusing on stress signals and detailed description. Literary part of the closing chapter on the effects of stress on photosynthesis and respiration and the impact of excess lime in the soil to grow grapevine rootstocks. Experimental part follows the results of the bachelor thesis, when being monitored by simulation of stress in vitro only unrooted rootstocks Kober 125 AA when the measured responses of plants to plant growth (length and weight) and their physiological response (quantum yield of photosynthesis, the production of ethylene, ethane, CO2 content and photosynthetically active pigments). These results are in the thesis completed by the determination of the abscisic acid in the above - ground parts of plants. In this thesis, the experiment was performed with the stage of the plant - unrooted nodal segments rootstock Börner shoots and rooted rootstock Börner and Kober 125 AA.
40

Fyziologické a molekulární odezvy vodních organizmů na účinky chemických látek

CHUPANI, Latifeh January 2017 (has links)
The biochemical and physiological responses of organisms to xenobiotic chemicals have been investigated for many years as general indicators of organism health. These markers have been used in the development of the synthetic pharmaceuticals and screening of effects of environmental pollutant on biological systems, and in clarifying their modes of action. Recently, use of "OMICS" approaches has received great attentions in exploring the effects of chemical contaminants at the molecular level and is one of the rapidly developing areas in the field of toxicology. Use of molecular response within aquatic organisms has been reviewed and are considered as early changes occurring in response to chemical exposure. ZnO NPs are widely used and possess great potentials in food industry and agriculture. Their subsequent release into environment has raised concerns about their potential effects on aquatic organisms. Although, the dietary exposure perhaps is the main route to expose aquatic animals to nanomaterials, the majority of studies are focused on assessment of waterborne exposure. The molecular mechanisms inducing their toxicity on biological system even less investigated. The present study was conducted to explore weather ZnO NPs can be accumulated in internal organs of carp, as a model fish, as well as to assess fish responses to the presence of ZnO NPs in the feed at protein, biochemical, and histological levels. Our results showed nor apparent accumulation of ZnO NPs neither major changes in haematological parameters, lipid peroxidation level, and histology of internal tissues. Our observations showed that 500 mg ZnO NPs per kg of feed caused changes in pathways and the level of proteins associated with cell motility, immune system response, protein synthesis, cell metabolism, and cell survival in intestine as well as it affected the proteins related to immune system in serum. Treated fish underwent these physiological and molecular changes probably attempted to adjust to ZnO NPs as an external stressor. These changes can be considered as compensatory mechanisms to maintenance homeostasis which have an associated energetic cost. If energetic demands to cope with stress exceeds the capacity of limit, then organism's health will be negatively affected. In the second part of study, peracetic acid in tested therapeutic doses (1 and 3 mg L-1 in grass carp and 10 mg L-1 in signal crayfish) caused some histological alterations in gills as well as changes in the activities of antioxidant enzyme in treated animals. It seems that the observed changes were not large enough to induce mortality in treated animals. According our observation after recovery period, it seems that those changes are reversible if it is followed by a sufficient recovery period allowing animals to restore their disturbed homeostasis. However, species-specific differences should be considered while treating more sensitive species. Toward establishing a safe application guideline, more studies will be required to investigate the given issues.

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