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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

Copper and zinc uptake by celery plants grown on acidic soil amended with biosolids

Haghighi, Maryam, Pessarakli, Mohammad 11 September 2015 (has links)
For trace elements, such as copper (Cu) and zinc (Zn), the bioavailability of these elements, Cu and Zn, in biosolids is important because both are essential elements and both are potential contaminants when biosolids are land applied. A greenhouse study was conducted in factorial experiment based on a completely randomized design (CRD) with four replications on a soil treated with four rates of Cu (0, 50, 100, and 150 mg/kg) and four rates of Zn (0, 150, 300, and 450 mg/kg) on celery plants to investigate the distribution and mobility of these elements as well as growth and antioxidant changes of celery. The results of antioxidant changes were inconclusive due to irregular changes with Zn and Cu applications. However, generally the results show that Cu did not affect superoxide dismutase (SOD) or peroxidase (POD) activities in most of the treatments. On the other hand, Zn stimulated SOD and POD activities in most of the treatments. The photosynthesis rate decreased with the applications of Cu and Zn at the rates above 100 and 300 mg/kg and increased in low Cu concentration (50 mg/kg) compared to S (soil without biosolid).
2

Síntese, análise estrutural e avaliação da atividade catalítica mimética da superóxido dismutase e peroxidases de complexos derivados do piridoxal e cobre / Synthesis, structural analysis and mimetic activity of superoxide dismutase and peroxidases of complex derivatives from pyridoxal and copper

Pereira, Mateus Brum 31 March 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents the synthesis and characterization of copper complexes that mimic the activity of the superoxide dismutase enzyme, which operates in the elimination of reactive oxygen species or in the activation of hydrogen peroxide. In the synthesis, the ligands used were obtained from the condensation of pyridoxal hydrochloride with substituted anilines possessing different halogens. Subsequently, a method was employed which enabled the quantification of antioxidant/pro-oxidant activity in order to find a correlation between the influence of the coordination geometry and the halogen position on the catalytic activity. In this study, the following thirteen compounds were synthesized: [Cu(Pyridoxal-H-aniline)2]Cl2·2H2O (C1), [Cu(Pyridoxal-2-F-aniline)2] (C2), [Cu(Pyridoxal-2-Cl-aniline)2] (C3), [Cu(Pyridoxal-2- Br-aniline)2] (C4), [Cu(Pyridoxal-2-I-aniline)2] (C5), [Cu(Pyridoxal-3-F-aniline)2] (C6), [Cu(Pyridoxal-3-Cl-aniline)2] (C7), [Cu(Pyridoxal-3-Br-aniline)2] (C8), [Cu(Pyridoxal-3- l-aniline)2] (C9), [2Cu(Pyridoxal-4-F-aniline)2] (C10), [2(Cu(Pyridoxal-4-Cl-aniline)2)] (C11), [2(Cu(Pyridoxal-4-Br-aniline)2)] (C12), and [2(Cu(Pyridoxal-4-I-aniline)2)] (C13). The methodology used to quantify the mimetic activity of the superoxide dismutase antioxidant was the photoreduction of NBT, and in the case of quantification of the peroxidase, a phenol oxidation method, using 4- aminoantipyrineas the indicator, was analyzed. The results showed that the mimetic compounds exhibit high activity levels of the superoxide dismutase and peroxidase enzymes. / Este trabalho apresenta a síntese e caracterização de complexos de cobre que mimetizam a atividade catalítica da enzima superóxido dismutase ou no processo de ativação de peróxido de hidrogênio. Na síntese dos complexos, foram utilizados ligantes obtidos a partir da condensação do cloridrato de piridoxal com anilinas substituídas com diferentes halogênios. Mais tarde, foram aplicadas metodologias para a quantificação da atividade antioxidante / pró-oxidante buscando uma correlação entre a influência da geometria de coordenação, bem como a posição dos átomos de halogênio sobre a atividade catalítica. Neste estudo, foram sintetizados os treze compostos seguintes: [Cu(Piridoxal-H-anilina)2]Cl2·2H2O (C1), [Cu(Piridoxal-2-F-anilina)2](C2), [Cu(Piridoxal-2-Cl-anilina)2](C3), [Cu(Piridoxal-2-Branilina) 2](C4), [Cu(Piridoxal-2-I-anilina)2] (C5), [Cu(Piridoxal-3-F-anilina)2] (C6), [Cu(Piridoxal-3-Cl-anilina)2] (C7), [Cu(Piridoxal-3-Br-anilina)2](C8), [Cu(Piridoxal-3-lanilina) 2] (C9), [2Cu(Piridoxal-4-F-anilina)2](C10), [2(Cu(Piridoxal-4-Clanilina) 2)](C11), [2(Cu(Piridoxal-4-Br-anilina)2)](C12),[2(Cu(Piridoxal-4-Ianilina) 2)](C13). A metodologia utilizada para quantificar a atividade mimética antioxidante da enzima superóxido dismutase foi a da fotorredução de NBT, e, no caso da quantificação da peroxidase foi usado o método de oxidação de fenol, utilizando como indicador a 4-aminoantipirina. Os resultados indicam que os compostos miméticos exibem uma elevada atividade da enzima superóxido dismutase, bem como peroxidase.
3

Complexos metálicos derivados de ligantes tripodais: Síntese, análise estrutural, aplicação como miméticos da atividade catalítica da superóxido dismutase e avaliação de citotoxidade frente à Caenorhabditis elegans in vivo. / Derived metal complexes tripodal ligands: Synthesis, structural analysis, application as mimetics of superoxide dismutase catalytic activity and evaluation of cytotoxicity in regarding to Caernohabditis elegans in vivo.

Ebani, Patrícia Regina 29 February 2016 (has links)
The proposed dissertation presents the synthesis, characterization and mimetic application of complexes containing metals cations of the first transition series like CuII, NiII, MnII and FeIII. As starting materials have been used as only aminic precursor the tripodal ligand TREN tris(2-aminoethyl)amine followed by different compounds containing an aldehyde function, among then the biologic active shape of B6 vitamin, the pyridoxal, in hydrochloride. The ligands used in complexation rise by reaction of condensation among listed reagents, forming Schiff bases, which are much important in the coordination sphere of synthetized complexes. The metallic salts used on the synthesis have been used in hydrated perchlorate shape. The molecular formulas of synthetized complexes in this paper are C1[Cu(C21H24N4].(ClO4)2; C2[Cu(C24H27N7].(ClO4)2; C3[Cu(C21H26O3N4)(H2O)].(ClO4)2; C4[Cu4(C60H80N14O15(H2O)2].(ClO4).(H2O)2; C5[Cu(C15H22N2O2)].(ClO4); C6Ni(C22H30N6O4)].(H2O)7; C7[Mn(C30H38N7O6].(ClO4).(H2O) e C8[Fe(C30H36N7O6)].(H2O). Structural analysis of the eight synthetized complexes are recorded in solid state by xray diffraction on monocrystal. For superoxide dismutation tests (mimetic activity to SOD enzyme) was performed by measurements on the visible and ultraviolet region. Further, it has been conducted auxiliary analyses of characterization like cyclic voltammetry, infrared and UVVis spectroscopy, for all compounds. The cytotoxicity of the first three synthesized complexes were evaluated against the Caenorhabditis elegans in vivo. / A dissertação proposta apresenta a síntese, a caracterização e a aplicação mimética de complexos contendo cátions metálicos da primeira série de transição como CuII, NiII, MnII e FeIII. Como materiais de partida utilizou-se como único precursor amínico o ligante tripodal TREN tris(2-aminoetil)amina seguido de diferentes compostos contendo a função aldeído, entre eles a forma biologicamente ativa da vitamina B6, o piridoxal, em forma de cloridrato. Os ligantes utilizados na complexação formam-se pela reação de condensação entre os reagentes supracitados formando bases de Schiff, as quais são de importância fundamental na esfera de coordenação dos complexos sintetizados. Os sais metálicos utilizados na síntese foram usados na forma de percloratos hidratados. As fórmulas moleculares dos complexos sintetizados neste trabalho são: C1[Cu(S3C21H24N4].(ClO4)2; C2[Cu(C24H27N7].(ClO4)2; C3[Cu(C21H26O3N4)(H2O)].(ClO4)2; C4[Cu4(C60H80N14O15)(H2O)2].(ClO4).(H2O)2; C5[Cu(C15H22N2O2)].(ClO4); C6[Ni(C22H30N6O4)].(H2O)7; C7[Mn(C30H38N7O6].(ClO4).(H2O) e C8[Fe(C30H36N7O6)].(H2O). Análises estruturais dos 8 complexos sintetizados foram feitas no estado sólido por difração de raios X em monocristal. Para os testes de dismutação do superóxido (atividade mimética à enzima SOD) foram realizadas medidas de absorção na região de ultravioleta e visível. Além disso, foram feitas análises auxiliares de caracterização como voltametria cíclica, espectrometria na região do UV-Vis e infravermelho. A citotoxidade dos três primeiros complexos sintetizados foram avaliadas frente à Caenorhabditis elegans in vivo.
4

Spectroelectrochemical determination of the antioxidant properties of carpobrotus mellei and carpobrotus quadrifidus natural products

Maoela, Manki Sarah January 2009 (has links)
Philosophiae Doctor - PhD / South African Carpobrotus species have been found to contain hydrolysable tannins,various flavonoids e.g. rutin and hyperoside, phytosterols and aromatic acids which have a diverse range of pharmacological properties including antimicrobial and, antioxidant activities. The main aim of the thesis was to determine the natural products in C. mellei and C. quadrifidus using chromatographic techniques and electrochemical analysis. The antioxidant activity of both Carpobrotus species was determined by using a superoxide dismutase (SOD) biosensor. ESI-LC-MS was used to separate and determine flavonoids in C. mellei and C. quadrifidus. 8 flavonoid compounds: catechin, epicatechin, epicatechin-epicatechin, coumarylquinic acid, isorhamnetin, quercetin-hexose (hyperoside), rutin and myricetin-deoxyhexose were identified. Cyclic and square wave voltammetry were used to detect flavonoids from C. mellei and C. quadrifidus. Catechin was detected in the ethyl acetate extract of C. mellei and C. quadrifidus. The oxidation potential of the plant extracts were observed at +150.6 mV to +1072.6 mV. The oxidation mechanism proceeds in sequential steps, related to the catechol moiety, -OH groups in C ring and the resorcinol group. The oxidation process of the catechol moiety involves a two electron - two proton reversible reaction and forms o-quinone. This occurs first at low potential and is a reversible reaction. The hydroxyl group in the C ring and resorcinol group oxidise there after and undergo an irreversible reaction. UV-vis and FTIR spectroscopy were used to confirm the presence of catechin in the ethyl acetate extract of both plants.UV-visible spectroelectrochemistry confirmed the oxidation process of catechin at constant potential. Since C. mellei and C. quadrifidus were confirmed to contain flavonoids by ESI-LC-MS and electrochemical analysis, the antioxidant activity was further investigated using a SOD biosensor. The superoxide dismutase (SOD) enzyme was immobilised with 1% Nafion on a platinum electrode. Detection limit and sensitivity of the SOD biosensor were found to be 0.03918 μmol L-1 and 1.44 μA(μmol L-1)-1, respectively. The results showed that C. mellei and C. quadrifidus have antioxidant activity, with relative antioxidant capacity (RAC) of 24% and 42%, respectively. May 2009
5

Application of dietary b-1,3-glucan in enhancing resistance of Penaeus monodon against vibrio and viral infections

Chang, Cheng-Fang 17 July 2000 (has links)
Three series of studies were conducted to quantify the effectiveness of dietary incorporation of b-1,3-glucan (BG) from Schizophyllum commune in enhancing the immunity and resistance of grass prawn Penaeus monodon to vibriosis and white spot syndrome virus (WSSV) infections. In the first series of studies, three experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on shrimp growth and resistance to vibriosis. Weight gain, survival and feed efficiency of juvenile shrimp (0.5 ¡Ó 0.1 g) were not significantly different (P>0.05) after being fed the diets containing BG 0, 0.2, 2, 10 g/kg diet for 18 weeks. Subadult shrimp (20.4 ¡Ó 2.1 g) fed the diet containing of BG 2 g/kg diet for 10 days showed a significantly (P<0.001) enhanced resistance against vibriosis. Postlarvae fed with the BG diet (2 g/kg diet) were more resistant (P<0.001) against starvation and V. harveyi challenges than the postlarvae fed non-BG diet. Additive disease resistance was observed when polyphosphorylated L-ascorbic acid (PAA) was used together with BG. In challenge tests with V. damsela, shrimp fed with PAA (0.2 g/kg diet) + BG (2 g/kg diet) diet for 20 days had a survival rate up to 60%. In the second series of studies, two experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on wound healing and immunity in spawners. Dietary supplement of BG reduced the chance of infections, but did not help wound healing as did the supplement of PAA. And regardless of indoor or outdoor rearing, the survival rate of brooder (135 ¡Ó 25 g) fed the BG (2 g/kg diet) diet was higher (P<0.001) than that of the non-BG group. Fed the BG brooders showed enhanced haemocyte phagocytic activity, cell adhesion and superoxide anion production then the control group. Third series of studies evaluated the effectiveness against white spot syndrome virus (WSSV). Six days after being challenged with WSSV, 12.2 % of the BG-treated (2 g/kg diet for 15 days) postlarvae (PL15) and 20 % BG-treated (2 g/kg diet for 20 days) juveniles (5.5 ¡Ó 0.5 g) were still alive; while all non-BG-treated shrimp died. In order to quantify the effectiveness of BG to WSSV, juveniles (6.5 ¡Ó 0.4 g) were fed diets containing graded levels of BG. The results showed that shrimp fed the diet containing BG 10 g/kg for 20 days had the highest (P<0.001) survival rate (42 %) among all groups. Shrimp that received diets supplemented with BG at a dosage >2 g/kg recuperated 9 ~ 12 days after WSSV challenge; while the group fed diets with no or 1 g/kg BG suffered from rapid decrease in total haemocyte count, phagocytic activity, phenoloxidase, O2-, superoxide dismutase (SOD) production and subsequent high mortality. The results in this study showed that b-1,3-glucan is effective in enhancing the phagocytic activity, phenoloxidase, O2- and SOD productions and consequently the resistance of postlarval, juvenile, subadult and brooder P. monodon against vibriosis and viral infections. Since prolonged use of BG, even at optimal dietary levels, decreased the immunity of the shrimp, care therefore must be taken to maximize its effectiveness. A cycle of dietary BG supplement of 2 ~ 10 g/kg diet for 20 days with an intermission of 10 days may serve the purposes.

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