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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.
1

Cucumis myriocarpus biotest solutions with antihelmintic and antibacterial solutions

Muedi, Hangwani Tshisevhe Hamilton January 2005 (has links)
Thesis(M.Sc.)--University of Limpopo, 2005. / Experiments were conducted to select suitable solvents for extracting nematicidal and bacterial chemical compounds from ground fruits of wild cucumber (Cucumis myriocarpus). Solvents and mixtures tested include 80% hexane: 20% dichloromethane, 80% n-hexane: 20% methanol, 20% n-hexane: 80% methanol, 100% dichloromethane, 80% n-hexane: ethanol, 100% methanol, 100% acetone, 100% toluene, 100% water, 100% ethyl acetate, 100% petroleum ether, 100% n-hexane, total ethanolic extract, 100% hexane fraction, hexane-ethyl acetate (1:1, v/v) fraction, 100% ethyl acetate fraction and 100% methanol fraction. Selection of the solution with the highest antihelmtic effect was done through the standard bioactivity tests. The nematode species used in the bioactivity tests were the root-knot nematode (Meloidogyne incognita) and the citrus nematode (Tylenchulus semipenetrans). In M. incognita study, the bioactivity effect ranged from 87% to 95%, whereas in T. semipenetrans the range was from 83% to 96%. The ethanolic extract and 100% hexane fraction were the best solvents for use in assessing antihelmintic properties of C. myriocarpus fruit. The solvents used in antihelmintic studies, as well as 100% dichloromethane, 100% water, 100% acetone, 100% toluene, 100% petroleum ether and 100% n-hexane were tested for antibacterial properties. The bacteria used were a mixture of Bacillus species, namely, B. litcheniformis, B. laterosporus and B. chitinosporus. Extracts from C. myriocarpus fruit exhibited antibacterial properties towards Bacillus species. In all tests, vii 100% dichloromethane and 100% n-hexane were the best solvents for use in assessing antibacterial properties of C. myriocarpus fruits. Minimum inhibitory concentration (MIC) of the solvents were determined using the biotest solutions extracted from 70.1 g C. myriocarpus. The 100% ethyl acetate and 100% petroleum ether had the lowest MIC of 3.13 mg/ml each, whereas in the 500 g material, hexane-ethyl acetate (1:1, v/v) and 100% ethyl acetate had the MIC of 0.78 mg/ml each. Results of the study confirmed the antihelmintic properties of C. myriocarpus fruits. Also, they demonstrated for the first time the antibacterial properties of C. myriocarpus fruits towards Bacillus species. / National Research Foundation.
2

Ekotoxikologické hodnocení biologicky aktivních látek / Ecotoxicological evaluation of biologically active substances

Čeganová, Renáta January 2014 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Bc. Renáta Čeganová Supervisor: RNDr. Jitka Vytlačilová, Ph.D. Title of diploma thesis: Ecotoxicological evaluation of biologically active substances For the observation of the ecotoxicological effects was selected griseofulvin that can be used as antifungal drug and local anesthetic dibucaine hydrochloride. Their analysis was performed by using a multigenerational test with a protozoan Tetrahymena thermophila, Rotoxkit F test with a rotifer Brachionus calyciflorus and algal test with Desmodesmus subspicatus. The mortality or inhibitory effects of the test substances on the growth of organisms was observed. The most sensitive of the test organisms for dibucaine hydrochloride was rotifer Brachionus calyciflorus and for griseofulvin it was alga Desmodesmus subspicatus. Keywords: ecotoxicity, biologically active substances, endpoint, biotests
3

Hodnocení alkaloidů pomocí in vivo testů s Artemia salina II. / Evaluation of alkaloids using in vivo tests with Artemia salina II.

Bystrońová, Beáta January 2015 (has links)
1 ABSTRACT Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Beáta Bystrońová Consultant: RNDr. Jitka Vytlačilová, Ph.D. Title of diploma thesis: The evaluation of alkaloids using in vivo tests with Artemia salina II. The most common cause of dementia in the elderly is probably Alzheimer's disease (AD). The prevalence of this disease increases considerably. Nowadays only acetylcholinesterase inhibitors are being used for the treatment of AD, they can relieve symptoms of AD, but can't stop progression of the disease. Consequently there is a need for therapeutic agents against AD, which act on various pathological levels. More intensive recent studies are being carried out on natural substances that could pharmacologically affect AD neurodegenerative processes. Our aim was to carry out the toxicological screening for each tested substance. For the purpose of this work we have used Artemia salina in the experiment which seems to be suitable organism for evaluating acute toxicity. The experiment was conducted in a miniature environment. Four substances which belong to isoquinoline alkaloids: stylopine, tetrahydropalmatine, canadine and scoulerine were tested. The greatest toxicity showed stylopine, slightly lower tetrahydropalmatine and...
4

Hodnocení alkaloidů pomocí in vivo testů s Artemia salina I. / Evaluation of alkaloids using in vivo tests with Artemia salina I.

Balíková, Barbora January 2014 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Barbora Balíková Consultant: RNDr. Jitka Vytlačilová, Ph.D. Title of diploma thesis: The evaluation of alkaloids using in vivo tests with Artemia salina I. Alzheimer's disease is the most common cause of dementia and it is one of the lifestyle diseases. There is so far available only limited symptomatic treatment and the occurrence of the lifestyle diseases (and thus Alzheimer's disease) is increasing in recent decades. Therefore it is necessary to find new compounds which will be effective in the treatment of this disease. Toxicological screening - which was our task - is the part of the research of each substance. For the evaluation of the acute toxicity appears as a suitable organism brine shrimp Artemia salina, which was used in the experiment for the purposes of this work. The experiment was conducted in a miniaturized environment. There were tested three substances belonged to the isoquinoline alkaloids: californidine, papaverine and morphine. As the most toxic was evaluated alkaloid californidine, alkaloid papaverine had less toxicity. Morphine appeared essentially as nontoxic with using the same methodology and similar concentrations as in the case of californidine...
5

Hodnocení přírodních látek pomocí in vivo testů s Artemia salina / Evaluation of natural substances using in vivo tests with Artemia salina

Ježková, Vendula January 2017 (has links)
1 Abstract Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Author: Vendula Ježková Supervisor: RNDr. Jitka Vytlačilová, Ph.D. Title of diploma thesis: Evaluation of natural substances using in vivo tests with Artemia salina Biological activity evaluation of substances is important because of toxic effect's assessment on chemical and physiological functions of organisms and their parts. For acute toxicity evaluation was used crustacean Artemia salina in this study. They were tested aqueouses extracts isolated from various plant drugs of Salviae folium, Apii semen, Coptidis rhizoma, Evodiae fructus, Zanthoxyli radix and Ziziphi fructus and two isolated alkaloids galanthamine and huperzine A. For each extract and alkaloid was calculated value of lethal concentration LC50. Results of this study showned, that the extract of Coptis chinensis, LC50 = 0,134 ± 0,004 mg/ml, had most toxic effects. Further the extract's toxicity decreased in the order Ziziphus jujuba, LC50 = 0,817 ± 0,165 mg/m > Zanthoxylum nitidum, LC50 = 1,154 ± 0,015 mg/ml > Salvia officinalis, LC50 = 2,074 ±0,462 mg/ml > Evodia rutaecarpa, LC50 = 2,166 ± 0,244 mg/ml > Apium graveolens, LC50 = 4,041 ± 0,108 mg/ml. Tested alkaloids don't demonstrated any toxicity activity in determinated...
6

Ekotoxicita vybraných pesticidů / Ecotoxicity of selected pesticides

Konečná, Veronika January 2013 (has links)
Presented diploma thesis is focused on the ecotoxicological evaluation of insecticide mixtures Perfekthion and Bulldock 25 EC and their effective substances, dimethoate and beta-cyfluthrin, respectively. Dimethoate is an organophosphate insecticide while beta-cyfluthrin belongs to pyrethroids. Both mixtures’ target organisms are sucking and biting pests on grain crops, potatoes, vegetables, oilseed rape and ornamental flowers. Their application over large areas and transport in large volumes generates a significant risk of entering the environment. Mixtures and substances were tested on water plant Lemna minor, algae Desmodesmus quadricauda and crustaceans Daphnia magna and Thamnocephalus platyurus. The LC50, EC50, and IC50 values were determined and ecotoxicity of substances and mixtures was evaluated and compared.
7

Hodnocení kalů a sedimentů pomocí testů ekotoxicity / Sewage sludge and sediments evaluation via ecotoxicity tests

Ondrová, Jana January 2013 (has links)
Sediments and sewage sludges are part of the environment. Sewage sludges are formed in wastewater treatment plants as solid residues after water purification, therefore they have antropogenic origine. Although the sediment are formed by natural processes, humans also contribute to their formation. Sediments and sewage sludges can be a reservoir of a number of contaminants, due to their properties. Utilisation of sediments and sewage sludges as material for recultivation or a natural fertilizer is currently supported. But after application to the land, contaminants can be released to the environment. The consideration of ecotoxicological effects of sediments and sewage sludges is very important. Sediments and sewage sludges were ecotoxicologicaly evaluated by bioassays with water leacheate and by whole sediment bioassays. Daphnia magna, Thamnocephalus platyurus, Sinapis alba and Lemna minor were used to perform tests with water leacheate. Heterocypris incongruens, Lactuca sativa and Eisenia fetida were used to perform whole sediment tests.
8

Investigação da toxicidade, tratabilidade e formação de subprodutos tóxicos em efluentes clorados de lagoas de estabilização com e sem pós-tratamento. / Investigation of toxicity, treatability and toxic disinfection by-products formation in chlorinated stabilization ponds effluents with and without post-treatment.

Léo, Luís Fernando Rossi 16 April 2008 (has links)
Entre as principais dificuldades que os sistemas de tratamento de esgotos domésticos compostos por lagoas de estabilização enfrentam para atender as exigências impostas pela Resolução CONAMA 357/2005 podem se destacar as concentrações elevadas de nitrogênio amoniacal, fósforo e coliformes fecais e totais. Estes últimos, quando os sistemas utilizam corpos receptores classe 2 ou 3 geram a necessidade de desinfecção. Dentre as diversas tecnologias disponíveis para a desinfecção dos esgotos, a cloração é bastante atrativa pelo custo reduzido, em relação às outras tecnologias, bem como pela elevada experiência que as companhias e municipalidades possuem neste tipo de sistema, advinda dos sistemas de tratamento de água. Dentre os sistemas de cloração, o uso de hipoclorito de sódio torna-se interessante pela segurança, simplicidade das instalações e de operação. A desvantagem do uso deste tipo de sistema se dá na possibilidade da formação de subprodutos tóxicos, dentro os quais pode-se destacar os trihalometanos (THMs) e os ácidos haloacéticos (AHAs), porém esta formação pode ser teoricamente reduzida pela presença de elevadas concentrações de nitrogênio amoniacal nos efluentes destes sistemas, por sua reação preferencial com o cloro, na formação de cloraminas. Outras possibilidades de redução na formação é reduzir a concentração de precursores, reduzir a dosagem de cloro e utilizar método de descloração dos efluentes após a desinfecção. Este trabalho, ambientado no desenvolvimento das pesquisas do Edital 4 do PROSAB/FINEP (Programa Nacional de Pesquisa em Saneamento Básico), desenvolveu testes de desinfecção em efluentes de lagoas anaeróbias e facultativas utilizando como desinfetante hipoclorito de sódio, em dosagens de 8,0 mgCl/L e 12,0 mgCl/L. Desenvolveu também testes de desinfecção com efluentes anaeróbios e facultativos pós-tratados por meio de coagulação/floculação/sedimentação e coagulação/floculação/flotação com ar dissolvido, com dosagens de 2,0 mgCl/L e 4,0 mgCl/L. Para todos os testes de desinfecção foram realizados também testes de descloração das amostras. Desta forma foi possível estudar, dentro de uma faixa limitada, as possibilidades de reduzir a formação de subprodutos tóxicos na desinfecção de efluentes de lagoas de estabilização com hipoclorito de sódio. Nas amostras foram determinados por meio de cromatografia gasosa as concentrações dos THMs e AHAs. Por meio das metodologias do Standard Methods 20th Edition foram realizadas as análises físico-químicas dos parâmetros pH, temperatura, DQO, DBO, Ntotal, N-NH3, NTK, cloro livre, cloraminas, coliformes e outros microrganismos indicadores. A formação de THMs se mostrou bastante pequena, em média abaixo dos 20,0 µg/L em todos os testes, aparentemente devido às elevadas concentrações de N-NH3, da ordem de 30,0 mg/L. O mesmo não ocorreu com os AHAs. Em muitos testes a concentração encontrada de AHAs totais superou o padrão de 80,0 µg/L preconizados pela USEPA para água potável, e aqui adotado como padrão comparativo. A descloração reduziu em média 52% a concentração de AHAs nos testes, colocando quase todas as amostras dentro do padrão de 80,0 µg/L. Os bioensaios mostraram que a presença de cloro livre nas amostras eleva a toxicidade aguda em Daphnia similis provocada pelos efluentes e que a cloração seguida de descloração produz efluentes com toxicidade inferior à toxicidade dos efluentes apenas clorados e toxicidade também inferior àquela dos efluentes sem cloração. / The main difficulties that the stabilization ponds for sewage treatment systems face to meet the requirements imposed by CONAMA Resolution 357/2005 can highlight the high concentrations of ammonia nitrogen, phosphorus and fecal and total coliform. When the systems use receivers water bodies Class 2 or 3 generate the need for disinfection. Among the different technologies available for the disinfection of sewage, the chlorination is very attractive at reduced cost compared to other technologies, as well as the high experience that companies and municipalities have in this type of system, because the water treatment systems. About the chlorination technologies, the use of sodium hypochlorite becomes interesting for security, simplicity of installation and operation. The disadvantage of using this type of system is given the possibility of formation of toxic by-products, within which you can highlight the trihalomethanes (THMs) and haloacetic acids (AHAs), but this formation can theoretically be reduced by the presence of high concentrations of ammoniacal nitrogen in effluents of these systems, for its preferential reaction with the chlorine in the formation of cloraminas. Other possibilities for reducing the training is to reduce the concentration of precursors (organic matter), reduce the dosage of chlorine and use dechlorination method after disinfection. This work, developed in PROSAB / FINEP (National Program for Research on Sanitation) research announcement number 4, developed tests for disinfection of anaerobic and facultative ponds effluents using sodium hypochlorite as a disinfectant, in concentrations of 8.0 mgCl/L and 12.0 mgCl/L. Were also developed tests for disinfection with anaerobic and facultative ponds effluents post-treated by coagulation / flocculation / sedimentation and coagulation / flocculation / flotation with dissolved air, with concentrations of 2.0 mgCl/L and 4.0 mgCl/L. For all of disinfection tests were also conducted dechlorination tests. This made it possible to study the possibilities of reducing the formation of toxic byproducts of the stabilization ponds effluents disinfection with sodium hypochlorite. The THMs and AHAS concentrations were determined by gas chromatography. Through the methods of Standard Methods 20th Edition analyses were carried out physical-chemical parameters of pH, temperature, COD, BOD, total nitrogen, ammoniacal nitrogen, total Kjeldhal nitrogen, free chlorine, chloramines, coliforms and other indicator microorganisms. The formation of THMs was very low, on average below the 20.0 µg/L in all tests, apparently due to high concentrations of NH3-N, the order of 30.0 mg/L. The same did not occur with AHAs. In many tests found concentrations of AHAs exceeded the standard of 80.0 µg/L recommended by the USEPA for drinking water. Dechlorination reduced 52% of AHAs concentrations, in average. Bioassays showed that the presence of free chlorine in the samples increase the acute toxicity in Daphnia similes. Chlorination followed by dechlorination produces effluents with less toxicity than the toxicity of chlorinated and effluent without chlorination.
9

Investigação da toxicidade, tratabilidade e formação de subprodutos tóxicos em efluentes clorados de lagoas de estabilização com e sem pós-tratamento. / Investigation of toxicity, treatability and toxic disinfection by-products formation in chlorinated stabilization ponds effluents with and without post-treatment.

Luís Fernando Rossi Léo 16 April 2008 (has links)
Entre as principais dificuldades que os sistemas de tratamento de esgotos domésticos compostos por lagoas de estabilização enfrentam para atender as exigências impostas pela Resolução CONAMA 357/2005 podem se destacar as concentrações elevadas de nitrogênio amoniacal, fósforo e coliformes fecais e totais. Estes últimos, quando os sistemas utilizam corpos receptores classe 2 ou 3 geram a necessidade de desinfecção. Dentre as diversas tecnologias disponíveis para a desinfecção dos esgotos, a cloração é bastante atrativa pelo custo reduzido, em relação às outras tecnologias, bem como pela elevada experiência que as companhias e municipalidades possuem neste tipo de sistema, advinda dos sistemas de tratamento de água. Dentre os sistemas de cloração, o uso de hipoclorito de sódio torna-se interessante pela segurança, simplicidade das instalações e de operação. A desvantagem do uso deste tipo de sistema se dá na possibilidade da formação de subprodutos tóxicos, dentro os quais pode-se destacar os trihalometanos (THMs) e os ácidos haloacéticos (AHAs), porém esta formação pode ser teoricamente reduzida pela presença de elevadas concentrações de nitrogênio amoniacal nos efluentes destes sistemas, por sua reação preferencial com o cloro, na formação de cloraminas. Outras possibilidades de redução na formação é reduzir a concentração de precursores, reduzir a dosagem de cloro e utilizar método de descloração dos efluentes após a desinfecção. Este trabalho, ambientado no desenvolvimento das pesquisas do Edital 4 do PROSAB/FINEP (Programa Nacional de Pesquisa em Saneamento Básico), desenvolveu testes de desinfecção em efluentes de lagoas anaeróbias e facultativas utilizando como desinfetante hipoclorito de sódio, em dosagens de 8,0 mgCl/L e 12,0 mgCl/L. Desenvolveu também testes de desinfecção com efluentes anaeróbios e facultativos pós-tratados por meio de coagulação/floculação/sedimentação e coagulação/floculação/flotação com ar dissolvido, com dosagens de 2,0 mgCl/L e 4,0 mgCl/L. Para todos os testes de desinfecção foram realizados também testes de descloração das amostras. Desta forma foi possível estudar, dentro de uma faixa limitada, as possibilidades de reduzir a formação de subprodutos tóxicos na desinfecção de efluentes de lagoas de estabilização com hipoclorito de sódio. Nas amostras foram determinados por meio de cromatografia gasosa as concentrações dos THMs e AHAs. Por meio das metodologias do Standard Methods 20th Edition foram realizadas as análises físico-químicas dos parâmetros pH, temperatura, DQO, DBO, Ntotal, N-NH3, NTK, cloro livre, cloraminas, coliformes e outros microrganismos indicadores. A formação de THMs se mostrou bastante pequena, em média abaixo dos 20,0 µg/L em todos os testes, aparentemente devido às elevadas concentrações de N-NH3, da ordem de 30,0 mg/L. O mesmo não ocorreu com os AHAs. Em muitos testes a concentração encontrada de AHAs totais superou o padrão de 80,0 µg/L preconizados pela USEPA para água potável, e aqui adotado como padrão comparativo. A descloração reduziu em média 52% a concentração de AHAs nos testes, colocando quase todas as amostras dentro do padrão de 80,0 µg/L. Os bioensaios mostraram que a presença de cloro livre nas amostras eleva a toxicidade aguda em Daphnia similis provocada pelos efluentes e que a cloração seguida de descloração produz efluentes com toxicidade inferior à toxicidade dos efluentes apenas clorados e toxicidade também inferior àquela dos efluentes sem cloração. / The main difficulties that the stabilization ponds for sewage treatment systems face to meet the requirements imposed by CONAMA Resolution 357/2005 can highlight the high concentrations of ammonia nitrogen, phosphorus and fecal and total coliform. When the systems use receivers water bodies Class 2 or 3 generate the need for disinfection. Among the different technologies available for the disinfection of sewage, the chlorination is very attractive at reduced cost compared to other technologies, as well as the high experience that companies and municipalities have in this type of system, because the water treatment systems. About the chlorination technologies, the use of sodium hypochlorite becomes interesting for security, simplicity of installation and operation. The disadvantage of using this type of system is given the possibility of formation of toxic by-products, within which you can highlight the trihalomethanes (THMs) and haloacetic acids (AHAs), but this formation can theoretically be reduced by the presence of high concentrations of ammoniacal nitrogen in effluents of these systems, for its preferential reaction with the chlorine in the formation of cloraminas. Other possibilities for reducing the training is to reduce the concentration of precursors (organic matter), reduce the dosage of chlorine and use dechlorination method after disinfection. This work, developed in PROSAB / FINEP (National Program for Research on Sanitation) research announcement number 4, developed tests for disinfection of anaerobic and facultative ponds effluents using sodium hypochlorite as a disinfectant, in concentrations of 8.0 mgCl/L and 12.0 mgCl/L. Were also developed tests for disinfection with anaerobic and facultative ponds effluents post-treated by coagulation / flocculation / sedimentation and coagulation / flocculation / flotation with dissolved air, with concentrations of 2.0 mgCl/L and 4.0 mgCl/L. For all of disinfection tests were also conducted dechlorination tests. This made it possible to study the possibilities of reducing the formation of toxic byproducts of the stabilization ponds effluents disinfection with sodium hypochlorite. The THMs and AHAS concentrations were determined by gas chromatography. Through the methods of Standard Methods 20th Edition analyses were carried out physical-chemical parameters of pH, temperature, COD, BOD, total nitrogen, ammoniacal nitrogen, total Kjeldhal nitrogen, free chlorine, chloramines, coliforms and other indicator microorganisms. The formation of THMs was very low, on average below the 20.0 µg/L in all tests, apparently due to high concentrations of NH3-N, the order of 30.0 mg/L. The same did not occur with AHAs. In many tests found concentrations of AHAs exceeded the standard of 80.0 µg/L recommended by the USEPA for drinking water. Dechlorination reduced 52% of AHAs concentrations, in average. Bioassays showed that the presence of free chlorine in the samples increase the acute toxicity in Daphnia similes. Chlorination followed by dechlorination produces effluents with less toxicity than the toxicity of chlorinated and effluent without chlorination.
10

Posouzení vlivů běžně používaných hasiv na vybrané složky životního prostředí / Impact assessment of ordinarily used firefighting agents on selected environmental compartments

Jabandžievová, Barbora January 2017 (has links)
This diploma thesis is focused on the evaluation of effects of the most frequently used extinguishing agents in the South Moravian region on selected aquatic and terrestrial organisms. Extinguishing substances which have been tested are foaming agents Sthamex and Moussol, rigid wetting agent TS ECO and TS Turbo and ABC FAVORIT fire - extinguishing powder. Their effects have been tested on aquatic organisms Daphnia magna and Scenedesmus subspicatus and terrestric organisms such as Folsomia candida, Lactuca sativa, and Eisenia fetida. Validation test on standard substances have been performed to verify the validity of the test results. From the obtained results values of IC50, LC50 and EC50 were calculated, through which the impact of individual extinguishing agents on the components of the environment was assessed.

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