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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

Padidintų geležies sulfato ir glicinato kiekių įtaka viščiukų broilerių produktyvumui ir paukštienos kokybei / Increased quantities of ferrous sulfate and glycinate influence on broiler chickens productivity and poultry meat quality

Bružinskaitė, Edita 18 June 2014 (has links)
Darbo tikslas: ištirti padidintų geležies sulfato ir geležies glicinato kiekių įtaką viščiukų broilerių produktyvumui ir paukštienos kokybei. Darbo uždaviniai: 1. Ištirti padidintų geležies sulfato ir glicinato kiekių įtaką viščiukų broilerių augimo intensyvumui; 2. Ištirti padidintų geležies sulfato ir glicinato kiekių įtaką viščiukų broilerių lesalų sąnaudoms bei išsaugojimui; 3. Ištirti padidintų geležies sulfato ir glicinato kiekių įtaką viščiukų broilerių skerdenos morfologinei sudėčiai; 4. Ištirti padidintų geležies sulfato ir glicinato kiekių įtaką viščiukų broilerių krūtinėlės ir šlaunelių raumenų pH dinamikai, geležies ir malondialdehido (MDA) kiekių susikaupimui, bei mėsos juslinėms savybėms. Tyrimo metodika: Lesinimo bandymas buvo atliekamas 35 dienas su Ross 308 linijų derinio viščiukais broileriais. Viščiukai broileriai buvo suskirstyti į 3 grupes po 200 viščiukų kiekvienoje grupėje. Pirmoji grupė kontrolinė, likusios – tiriamosios. Kontrolinės grupės viščiukai broileriai buvo lesinami standartiniais kombinuotaisiais lesalais, į kuriuos buvo įterpta 70 mg geležies sulfato. Į I tiriamosios grupės standartinius kombinuotuosius lesalus – 144 mg geležies glicinato, o II tiriamosios grupės lesalus buvo įterpta 150 mg geležies sulfato. Tyrimo rezultatai ir išvados: Analizuojant 35 dienų amžiaus duomenis, abiejuose tiriamosiose grupėse viščiukų broilerių kūno masė padidėjo 1 proc., lyginant su kontroline grupe (p>0,05), o lesalų sąnaudos 1 kg priesvorio gauti... [toliau žr. visą tekstą] / The aim of work (research): investigate the increased quantities of ferrous sulfate and glycinate influence on broiler chickens productivity and poultry meat quality. The tasks of the work: 1. to investigate the increased quantities of ferrous sulfate and glycinate influence to the intensity of broiler chickens’ growth; 2. to investigate the increased quantities of ferrous sulfate and glycinate influence to the input and preservation of broiler chickens’ feed; 3. to investigate the increased quantities of ferrous sulfate and glycinate influence to the morphological composition of broiler chickens’ carcase; 4. to investigate the increased quantities of ferrous sulfate and glycinate influence to the breast and thigh muscle pH dynamics, iron and malondialdehyde (MDA) quantities accumulation and sensory properties of the broiler chickens’ meat. Research methodology: The feeding experiment took 35 days and was performed with the Ross 308 broiler chickens line combination. Broilers were divided into 3 groups of 200 broilers in each. The fowl of all 3 groups were fed with a standard composite feed. The first control group, the rest - the test. The control group of chickens were fed the standard composite feed, containing 70 mg of ferrous sulfate. In the I treatment group compound feeds was added- 144 mg ferrous glycinate, and group II feeds has been added to 150 mg of ferrous sulfate. Broiler chickens were fed ad libitum. Research results and conclusion: Analysis of 3... [to full text]
32

Prevenção da anemia ferropriva em crianças: foco na adesão ao uso do sulfato ferroso / Prevention of iron deficiency anemia in children: focus on adherence to the use of ferrous sulfate

Henrique, Nayara Cristina Pereira 05 June 2017 (has links)
O estudo teve por objetivos caracterizar as crianças na faixa etária entre seis meses e 11 meses e 29 dias em seguimento em unidades de saúde da família, de acordo com dados de nascimento, maternos, alimentação e socioeconômicos; descrever aspectos sobre a prevenção da anemia ferropriva, com destaque para o uso preventivo do sulfato ferroso na perspectiva do cuidador principal da criança; e identificar elementos facilitadores e dificultadores da prevenção da anemia ferropriva na infância. Estudo descritivo e exploratório, desenvolvido em duas fases, sendo a primeira etapa com coleta de dados secundários de 183 prontuários, caracterizando o perfil das crianças de seis meses a 11 meses e 29 dias de idade em seguimento na estratégia saúde da família. Na segunda etapa, foram realizadas 12 entrevistas com o cuidador principal da criança, para apreender suas noções acerca da prevenção da anemia ferropriva e o uso do sulfato ferroso em crianças. Os resultados apontam informações sobre aleitamento materno, introdução da alimentação complementar, conhecimento sobre alimentos e formas de prevenção da anemia ferropriva, identificadas como elementos facilitadores para a prevenção dessa enfermidade. Por outro lado, o pouco reconhecimento sobre a enfermidade e seus malefícios à saúde da criança, o baixo número de crianças com prescrição do sulfato ferroso e a interrupção do uso do sulfato ferroso foram considerados como elementos que dificultam a prevenção da anemia ferropriva. O estudo conclui que o incentivo e apoio ao aleitamento materno exclusivo, o monitoramento do desmame precoce, a introdução de alimentos saudáveis, as informações sobre a anemia ferropriva e o uso cotidiano do sulfato ferroso em crianças devem ser mais bem trabalhados com as famílias e equipes de saúde da família, tendo em vista a promoção de práticas alimentares saudáveis e das práticas educativas em saúde. A presente investigação traz contribuições para expandir a prevenção de agravos e promoção da saúde infantil, particularmente com vistas ao manejo e diminuição da prevalência da anemia ferropriva em crianças / The objective of the study was to characterize children in the age group between six months and 11 months and 29 days in follow-up in family health units, according to birth, maternal, feeding and socioeconomic data; To describe aspects about the prevention of iron deficiency anemia, especially the preventive use of ferrous sulfate from the perspective of the child\'s primary caregiver; And to identify elements that facilitate and impede the prevention of iron deficiency anemia in childhood. A descriptive and exploratory study was carried out in two phases, the first stage with secondary data collection of 183 charts, characterizing the profile of children from six months to 11 months and 29 days of age in a follow-up in the family health strategy. In the second stage, 12 interviews were carried out with the child\'s primary caregiver to learn their notions about the prevention of iron deficiency anemia and the use of ferrous sulfate in children. The results point to information about breastfeeding, introduction of complementary feeding, knowledge about food and ways of preventing iron deficiency anemia, identified as facilitating factors for the prevention of this disease. On the other hand, the lack of recognition of the disease and its harmful effects on the health of the child, the low number of children with iron sulfate prescription and the interruption of the use of ferrous sulfate were considered as elements that make it difficult to prevent iron deficiency anemia. The study concludes that encouraging and supporting exclusive breastfeeding, monitoring early weaning, introducing healthy foods, reporting on iron deficiency anemia, and daily use of ferrous sulfate in children should be better handled with families and family health teams; the promotion of healthy eating practices and educational practices in health. The present research brings contributions to expand the prevention of injuries and promotion of child health, particularly with a view to the management and reduction of the prevalence of iron deficiency anemia in children
33

Desenvolvimento e caracterização de géis polissacarídicos carregados com emulsões e enriquecidos com nutrientes para suplementação de alimentação de leitões / Development and characterization of emulsion-filled polysaccharide gels enriched with nutrients for feeding supplementation of piglets

Souki, Nayla Padua Del Bianco Gontijo 17 March 2017 (has links)
O presente trabalho de Mestrado teve como objetivo produzir géis carregados de emulsão contendo nutrientes incorporados, visando a complementação da alimentação de leitões neonatos. Para alcançar tal objetivo, foram produzidas emulsões utilizando-se diferentes lipídios e tensoativos para definição preliminar sobre quais destes ingredientes seriam mais eficientes na formação de emulsões estáveis. As emulsões produzidas foram avaliadas em relação à distribuição de tamanho de gota e aspecto visual dentro de 24 h após a produção. A partir de tais resultados, algumas amostras foram escolhidas e foi estudado o aumento da concentração de lipídios, bem como a razão óleo:tensoativo e intensidade de agitação. Para cada emulsão estudada, esta era incorporada ao gel polissacarídico, e então realizava-se um estudo da estabilidade térmica a 40 e 50 °C. Após a definição da melhor concentração de lipídios, ocorreu o estudo da incorporação de nutrientes em diversas concentrações na emulsão. Novamente, as emulsões foram avaliadas por meio da distribuição de tamanho de gota, bem como pelo aspecto visual. Foi avaliada a estabilidade da emulsão ao longo de 28 dias, que indicou um sistema estável para o período indicado. Os géis carregados foram analisados quanto à quantidade de energia e à atividade de água, apresentando um baixo valor energético e atividade de água alta. Foram também caracterizados por análises reológicas, que indicaram que a presença da emulsão fortaleceu a estrutura do gel, indicando adesão das gotas à matriz biopolimérica. O gel carregado de emulsão apresentou estabilidade microbiológica, não tendo havido crescimento de fungos filamentosos e não-filamentosos, bem como a manutenção do pH. No entanto, houve alteração da cor ao longo da estocagem. Assim, foi possível produzir um gel carregado de emulsão contendo nutrientes, possibilitando a formação de um sistema estável. / The aim this work was to produce emulsion filled gels with the incorporation of nutrients for the complementation of nutrition of neonates piglets. For this, the emulsions were produced from a variety of lipids and surfactants to define, preliminarily, which of these ingredients would be efficient to form stable emulsions. The emulsions produced were evaluated by droplet size distribution and visual appearance within 24 hours after production. From these results, some samples were selected and the increase of lipid concentration was studied as well as the ratio oil:surfactant and the stirring intensity. For each emulsion studied, this was incorporated into the polysaccharide gel and then the thermal stability study at 40 and 50 °C was made. After setting the optimal concentration of lipids and a stirring intensity, there was the study of nutrientse incorporation at different concentrations in the emulsion. Again, the emulsions were evaluated by droplet size distribution, as well as by visual appearance. The emulsion stability was evaluated over 28 days, which indicated a stable system for this time. The emulsion filled gels were characterized for the amount of energy and water activity and presented as results low amount of energy and high water activity. In the rheological characterization, the results showed that the presence of emulsion strengthened the gel structure, indicating adhesion of the droplets to the biopolymer matrix. The emulsion filled gel showed microbiological stability has not been growing of filamentous and non-filamentous fungi, as well as pH stability. However, there was a change in color over the storage. Thus, it was possible to produce an emulsion-filled gel with nutrients, on which occurred the formation of a stable system.
34

Estudo comparativo entre os aumentos das ferremias, determinados sem a administração prévia de ferro; após as administrações de sulfato ferroso, e complexo ferro-peptídeo. / A comparative study of the increase in blood iron concentrations obtained without previous iron administration and after the administration of ferrous sulfate or an iron-peptide complex.

Sakamoto, Luiz Maçao 28 April 2003 (has links)
A deficiência de ferro e a anemia por deficiência de ferro (anemia ferropriva) são, ainda hoje, um dos maiores problemas nutricionais e de saúde pública em todo o mundo, afeta cerca de 2 bilhões de pessoas, especialmente nos países em desenvolvimento. Em geral os programas de prevenção e tratamento da anemia apresentam baixa adesão devido entre outros fatores a efeitos colaterais relacionados ao sistema gastrointestinal, resultantes da administração oral de compostos contendo ferro especialmente o sulfato ferroso. Dessa maneira, torna-se necessário o desenvolvimento de novas estratégias, compostos ou sistemas de liberação, que apresentem alta biodisponibilidade do ferro e minimizem ou eliminem os efeitos colaterais. Nesse sentido, o complexo ferro-peptídeo (CFP), devido as suas características físico-químicas que contrastam com aquelas apresentadas pelo sulfato ferroso (SF), torna-se uma possível alternativa como fonte de ferro. É um complexo orgânico com baixa solubilidade em pH ácido e totalmente solúvel em pH neutro a alcalino. Baseado nessas características, nos aumentos das ferremias (teores de ferro sérico ligado a apotransferrina) que ocorrem, em seres humanos, durante o período diurno observados por Wiltink et al. (1973) e no estudo realizado em ratos, por Dutra-de-Oliveira et al. (1995) comprovando resultados similares entre o sulfato ferroso e os complexos ferro-glicina e EDTA férrico, as hipóteses do presente estudo quando o complexo ferro-peptídeo é administrado por via oral, em homens saudáveis, foram: 1) induz aumentos significativos das ferremias quando comparados com os aumentos das ferremias controle (C), determinados sem a administração de ferro; 2) induz aumentos significativos iguais ou superiores aos determinados após a administração de sulfato ferroso utilizado como referência. Portanto, com o objetivo de testar as hipóteses, foram comparadas estatisticamente as variações das ferremias controle e as induzidas pelas administrações, de complexo ferro-peptídeo e sulfato ferroso. Essas variações foram determinadas a partir das diferenças entre as ferremias obtidas nas amostras coletadas de 10 homens adultos saudáveis, nos tempos: 30, 60, 120, 240, 480 e 720 minutos (’) e as obtidas no tempo zero, contados a partir do início da coleta. Cada voluntário submeteu-se aos tratamentos: recebeu no tempo 0, em jejum de 480’, com intervalo de 7 dias, as seguintes quantidades de ferro: 0mg (C), 60mg (FP1) e 80mg (FP2) como CFP, 60mg como SF, permanecendo por mais 720’ em jejum e 60mg como CFP com dieta isenta de inibidores de absorção de ferro durante e após a administração (FPD). O teste de Dunn demonstrou aumentos significativos das ferremias entre SFxC [60’(p<0,01), 120’(p<0,01), 240’(p<0,01)], SFxFP1 [120’(p<0,01), 240’(p<0,05), 480’(p<0,05)] e SFxFPD [240’(p<0,01), 480’(p<0,05)]. Entre as áreas sob as curvas ocorreram aumentos significativos nos intervalos de tempo: 0’–240’ [SFxC (p<0,01), SFxFP1 (p<0,05)], 240’–720’ [SFxFP1 (p<0,05), SFxFPD (p<0,05)] e 0’–720’ [SFxC (p<0,05), SFxFP1 (p<0,05), SFxFPD (p<0,05)]. Conclusões: As hipóteses iniciais não foram confirmadas. Não foram significativos os aumentos das ferremias após as administrações do complexo ferro-peptídeo quando comparados com os aumentos das ferremias controle, nos respectivos tempos. Esses aumentos foram significativamente menores que os determinados após a administração de sulfato ferroso, com exceção aos decorrentes da administração de complexo ferro-peptídeo em quantidade equivalente a 80 mg de ferro. / Iron deficiency and iron-deficiency anemia continue to be major nutritional and public health problems all over the world, affecting about 2 billion people, especially in developing countries. In general, programs for the prevention and treatment of anemia present low adhesion due, among other factors, to the side effects related to the gastrointestinal system resulting from the oral administration of iron-containing compounds, especially ferrous sulfate. Thus, it is necessary to develop new strategies, compounds or release systems presenting high iron bioavailability and minimizing or eliminating side effects. In this respect, the iron-peptide complex (IPC), due to its physicochemical characteristics differing from those of ferrous sulfate (FS), represents a possible alternative as a source of iron. It is an organic complex of low solubility at acid pH and fully soluble at neutral or alkaline pH. Based on these characteristics, on the increased blood iron concentrations (levels of serum iron bound to apotransferrin) occurring in human beings during the diurnal period as observed by Wiltink et al. (1973), and on the similar results obtained with FS and the iron-glycine and ferric EDTA complexes by Dutra-de-Oliveira et al. (1995) in a study on rats, the hypotheses tested in the present study in which the iron-peptide complex was administered orally to healthy men were: 1) the complex induces significant increases in blood iron concentrations compared to control (C) subjects receiving no iron administration; 2) induces significant increases equal to or higher than those obtained after administration of SF used as reference. Thus, in order to test these hypotheses, we compared statistically the variations in control blood iron concentrations and the concentrations induced by the administration of the iron-peptide complex and SF. The variations were determined from the difference between the blood iron concentrations obtained in samples collected from 10 healthy adult men at 30, 60, 120, 240, 480 and 720 minutes (’) and those obtained at time zero, counted starting from the beginning of collection. Each volunteer was submitted to the following treatments: at time 0, after a 480’fast he received at 7 day intervals the following amounts of iron: 0 mg (C), 60 mg (FP1) and 80 mg (FP2) as IPC, and 60 mg as FS. He then fasted for an additional 720’ and received 60 mg as IPC together with a diet free of inhibitors of iron absorption during and after administration (FPD). The Dunn test demonstrated significant increases in blood iron concentrations for FSxC [60’(p<0.01), 120’(p<0.01), 240’(p<0.01)], FSxFP1 [120’(p<0.01), 240’(p<0.05), 480’(p<0.05)] and FSxFPD [240’(p<0.01), and 480’(p<0.05)]. Significant increases occurred in the areas under the curve for the following comparisons at the following intervals: 0’–240’ [FSxC (p<0.01), FSxFP1 (p<0.05)], 240’–720’ [FSxFP1 (p<0.05), FSxFPD (p<0.05)] e 0’–720’ [FSxC (p<0.05), FSxFP1 (p<0.05), and FSxFPD (p<0.05)]. Conclusions: The initial hypotheses were not confirmed since the increase in blood iron concentrations after the administration of the iron-peptide complex was not significant compared to the increase in control blood iron concentration at the respective time points. These increases were significantly lower than those obtained after SF administration, except for those obtained after the administration of the iron-peptide complex at a quantity equivalent to 80 mg iron.
35

Prevenção da anemia ferropriva em crianças: foco na adesão ao uso do sulfato ferroso / Prevention of iron deficiency anemia in children: focus on adherence to the use of ferrous sulfate

Nayara Cristina Pereira Henrique 05 June 2017 (has links)
O estudo teve por objetivos caracterizar as crianças na faixa etária entre seis meses e 11 meses e 29 dias em seguimento em unidades de saúde da família, de acordo com dados de nascimento, maternos, alimentação e socioeconômicos; descrever aspectos sobre a prevenção da anemia ferropriva, com destaque para o uso preventivo do sulfato ferroso na perspectiva do cuidador principal da criança; e identificar elementos facilitadores e dificultadores da prevenção da anemia ferropriva na infância. Estudo descritivo e exploratório, desenvolvido em duas fases, sendo a primeira etapa com coleta de dados secundários de 183 prontuários, caracterizando o perfil das crianças de seis meses a 11 meses e 29 dias de idade em seguimento na estratégia saúde da família. Na segunda etapa, foram realizadas 12 entrevistas com o cuidador principal da criança, para apreender suas noções acerca da prevenção da anemia ferropriva e o uso do sulfato ferroso em crianças. Os resultados apontam informações sobre aleitamento materno, introdução da alimentação complementar, conhecimento sobre alimentos e formas de prevenção da anemia ferropriva, identificadas como elementos facilitadores para a prevenção dessa enfermidade. Por outro lado, o pouco reconhecimento sobre a enfermidade e seus malefícios à saúde da criança, o baixo número de crianças com prescrição do sulfato ferroso e a interrupção do uso do sulfato ferroso foram considerados como elementos que dificultam a prevenção da anemia ferropriva. O estudo conclui que o incentivo e apoio ao aleitamento materno exclusivo, o monitoramento do desmame precoce, a introdução de alimentos saudáveis, as informações sobre a anemia ferropriva e o uso cotidiano do sulfato ferroso em crianças devem ser mais bem trabalhados com as famílias e equipes de saúde da família, tendo em vista a promoção de práticas alimentares saudáveis e das práticas educativas em saúde. A presente investigação traz contribuições para expandir a prevenção de agravos e promoção da saúde infantil, particularmente com vistas ao manejo e diminuição da prevalência da anemia ferropriva em crianças / The objective of the study was to characterize children in the age group between six months and 11 months and 29 days in follow-up in family health units, according to birth, maternal, feeding and socioeconomic data; To describe aspects about the prevention of iron deficiency anemia, especially the preventive use of ferrous sulfate from the perspective of the child\'s primary caregiver; And to identify elements that facilitate and impede the prevention of iron deficiency anemia in childhood. A descriptive and exploratory study was carried out in two phases, the first stage with secondary data collection of 183 charts, characterizing the profile of children from six months to 11 months and 29 days of age in a follow-up in the family health strategy. In the second stage, 12 interviews were carried out with the child\'s primary caregiver to learn their notions about the prevention of iron deficiency anemia and the use of ferrous sulfate in children. The results point to information about breastfeeding, introduction of complementary feeding, knowledge about food and ways of preventing iron deficiency anemia, identified as facilitating factors for the prevention of this disease. On the other hand, the lack of recognition of the disease and its harmful effects on the health of the child, the low number of children with iron sulfate prescription and the interruption of the use of ferrous sulfate were considered as elements that make it difficult to prevent iron deficiency anemia. The study concludes that encouraging and supporting exclusive breastfeeding, monitoring early weaning, introducing healthy foods, reporting on iron deficiency anemia, and daily use of ferrous sulfate in children should be better handled with families and family health teams; the promotion of healthy eating practices and educational practices in health. The present research brings contributions to expand the prevention of injuries and promotion of child health, particularly with a view to the management and reduction of the prevalence of iron deficiency anemia in children
36

Efeito do acetato de chumbo associado ou não ao sulfato ferroso em cérebro de ratos: análise das enzimas antioxidantes / Effect of lead acetate with or without iron sulfate in brain of rats: Analysis of antioxidant enzymes

Ferreira, Maria Cecilia de Freitas 14 September 2012 (has links)
O chumbo (Pb) é um metal pesado, tóxico e está presente em diversos sistemas biológicos. Quando absorvido pelo organismo na forma iônica (Pb2+) atua em vários órgãos e sistemas, podendo ocasionar alterações graves no sistema nervoso central. Em adição, tem sido relatado que o íon ferroso (Fe2+) pode apresentar, entre outros, um efeito protetor na neurotoxicidade causada pelo Pb2+. Portanto, o objetivo deste estudo foi avaliar os marcadores de estresse oxidativo no cérebro de ratos expostos com acetato de chumbo (Pb(C2H3O2)2) associado ou não ao sulfato ferroso (FeSO4). Assim, 36 ratos machos (Rattus norvergicus) recém desmamados, divididos em 6 grupos (G), de 6 animais cada, foram expostos durante 6 semanas. No grupo controle (G1) os animais ingeriram água deionizada; G2 e G3 receberam 0,26 mM e G4 e G5 1,05 mM de acetato de chumbo, somado a isso G3 e G5 foram suplementados com 20 mg de sulfato ferroso/Kg peso corporal a cada 2 dias; e para G6 utilizou-se água deionizada e sulfato ferroso. O cérebro dos animais foi coletado para a análise da atividade enzimática de catalase (CAT), superóxido dismutase (SOD), glutationa peroxidase (GPx), a concentração de glutationa reduzida (GSH), lipoperoxidação (TBARS), hidroperóxido de lipídio (HL) e das substâncias antioxidantes totais (SAT) (técnicas ABTS e DPPH). A atividade das enzimas GPx e SOD nos grupos experimentais diminuiu em relação ao controle, assim como ocorreu com a concentração de GSH (p<0,05). Quanto às análises de HL e CAT, a primeira apresentou tendência de aumento na concentração dos grupos experimentais sem exposição concomitante, já a segunda demonstrou discreta inclinação de aumento na atividade em relação ao controle (p>0,05). A dosagem de SAT-ABTS mostrou aumento nos grupos expostos com 1,05 mM de acetato de chumbo. Em relação à SAT-DPPH houve diminuição nos grupos experimentais (p<0,05). De acordo com os resultados, as enzimas SOD e GPX e a GSH são afetadas pelo acetato de chumbo e a exposição ao sulfato ferroso altera essa dinâmica. No entanto, estudos posteriores são necessários para verificar se o sulfato ferroso funcionaria como protetor ao efeito tóxico do acetato de chumbo. / Lead (Pb2+) is a toxic heavy metal, found in all stages of the inert environment and in several biological systems. When uptaken by the organism, acts on several organs and systems and may cause severe damage in Central Nervous System. In addition, it has been reported that iron (Fe2+) may present, a protective effect on neurotoxicity caused by Pb2+. Therefore, the aim of this study was to evaluate the markers of oxidative stress in the brain of rats exposed with lead acetate (Pb(C2H3O2)2) associated or not with ferrous sulfate (FeSO4). Thus, 36 rats weaning (Rattus norvegicus) were, divided into 6 groups (G) of six animals and were exposed for six weeks.In the control group (G1), the animals received deionized water; G2 and G3 received 0,26 mM, G4 and G5 1,05 mM of lead acetate; in addition to this G3 and G5 were supplemented with 20mg of ferrous sulfate/Kg body weight every 2 days; G6 received deionized water and ferrous sulfate were used. The animals\' brains were collected for analysis of the enzymatic activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), the concentration of reduced glutathione (GSH), lipid peroxidation (TBARS), lipid hydroperoxide (LH) and total antioxidant substances (TAS) (ABTS and DPPH technics). The activity of the enzymes SOD and GPx in the experimental groups decrease compared to control, as well as the concentration of GSH (p<0.05). Concerning to the analysis of HL and CAT, the first tended to increase the concentration in experimental groups without concomitant exposure with FeSO4, while the second showed a slight tendency for increase in activity compared to control (p>0.05). The dosage of TAS-ABTS showed an increase in the groups exposed with 1,05 mM of lead acetate. Regarding the SAT- DPPH there was a decrease in the experimental groups (p <0.05). According to the results, the enzymes SOD and GPx and GSH were affected by lead acetate and exposure with ferrous sulfate change this dynamic. However, further studies are needed to verify if ferrous sulfate acts as a protective against toxic effect of lead acetate.
37

Produção de coagulante férrico a partir da lixiviação de concentrado de pirita da mineração de carvão via cristalização/solubilização de sulfato ferroso : estudo comparativo entre rejeitos de duas jazidas

Villetti, Pedro Ivo Chitolina January 2017 (has links)
O beneficiamento de carvão mineral para a utilização em termoelétricas gera grandes quantida-des de rejeitos, os quais contêm diversos minerais, entre eles a pirita (sulfeto de ferro - FeS2). A pirita, na presença de água e oxigênio se oxida, gerando a drenagem ácida de minas (DAM), principal fonte de contaminação dos aquíferos e do solo nas regiões carboníferas. Atualmente, a DAM é tratada pelo método de neutralização/precipitação de metais. Essa é uma técnica con-siderada “fim-de-tubo” com diversas desvantagens, entre elas o alto custo. Entretanto, através de técnicas preventivas, baseadas nos princípios da produção mais limpa, é possível, concomi-tantemente, minimizar a geração de DAM e agregar valor à parte ou totalidade dos rejeitos de carvão. Assim, o objetivo deste trabalho foi estudar a produção do coagulante sulfato férrico a partir da lixiviação de um concentrado de pirita oriundo de rejeitos de carvão via cristaliza-ção/solubilização de sulfato ferroso, comparando o processo para duas jazidas distintas de car-vão mineral. Amostras de concentrados de pirita foram obtidas de rejeitos de carvão das jazidas do Estado de Santa Catarina, minerados na cidade de Forquilhinha, e do Estado do Paraná, na cidade de Figueira A parte experimental foi realizada a partir de um reator de leito empacotado em planta-piloto e envolveu as seguintes etapas: produção de um lixiviado férrico, conversão do lixiviado férrico em ferroso, precipitação do Fe2+ e do sulfato na forma de cristais de sulfato ferroso heptahidratado com auxílio de etanol. Estudou-se, de forma detalhada, a proporção li-xiviado:etanol para o melhor rendimento do processo. Os cristais de sulfato ferroso produzidos a partir do concentrado de pirita catarinense apresentaram características semelhantes a um pa-drão analítico (menos de 1% de impurezas). Os cristais produzidos a partir da pirita paranaense apresentaram um índice levemente superior ao padrão estabelecido comercialmente (1,08%), além de apresentar alguns metais bastante perigosos à saúde, como arsênio. Também se estudou a produção do coagulante férrico via dissolução dos cristais de sulfato ferroso e oxidação do ferro pela adição de soluções aquosas com agentes ácidos e oxidantes. A melhor condição ob-tida foi a seguinte: 5 g de sulfato ferroso, 7,5 mL de água destilada, 1,5 mL de peróxido de hidrogênio e 5 gotas de ácido sulfúrico. Essa proporção proporcionou um coagulante com quase 12% de ferro, sendo que 97% deste ferro na forma férrica. O coagulante produzido foi utilizado no tratamento de água do corpo hídrico Guaíba, empregando-se como referência os padrões brasileiros de potabilidade (Portaria nº 2914 do Ministério da Saúde). Mostrando-se eficiente no tratamento de água para fins de abastecimento público. / The coal processing for use in power plants, generates amounts of residues, which contain var-ious minerals, such as pyrite (iron sulfide-FeS2). Pyrite, in the presence of water and oxygen, oxidizes, generating acid mine drainage (AMD), the main source of contamination of aquifers and soil in the carboniferous region of Santa Catarina. Currently, the AMD is treated by the method of neutralization/precipitation of metals. This is a technique considered "end-of-pipe" with many disadvantages, like the excessive cost. However, through preventive techniques, based on the principles of cleaner production, it is possible, at the same time, minimize the generation of AMD and to add value to a part or totality of coal waste. Thus, the objective of this work was to study the production of ferric sulphate coagulant from the leaching of a pyrite concentrate from coal tailings via crystallization / solubilization of ferrous sulphate, comparing the process to two distinct mineral coal deposits. Samples of pyrite concentrates were obtained from coal tailings from the State of Santa Catarina mines, mined in the city of Forquilhinha, and from the State of Paraná, in the city of Figueira The experimental part was carried out in a bed reactor packed in a pilot plant and involved the following steps: production of a ferric leachate, conversion of ferric leachate into ferrous, precipitation of Fe2 + and sulphate as crystals of ferrous sulphate heptahydrate. It was also studied, in detail, the proportion leached:ethanol for the best yield of the process. The ferrous sulphate crystals produced from the Santa Catarina pyrite concentrate showed characteristics similar to an analytical standard (less than 1% of im-purities). The crystals produced from the Paraná pyrite concentrate presented an index slightly higher than the commercially established standard (1.08%), besides presenting some metals very dangerous to health, such as arsenic. The production of ferric coagulant was also studied by dissolving the ferrous sulphate crystals and iron oxidation by adding aqueous solutions with acidic and oxidizing agents. The best condition obtained was as follows: 5 g of ferrous sulphate, 7.5 ml of distilled water, 1.5 ml of hydrogen peroxide and, 5 drops of sulfuric acid. This pro-portion provided a coagulant with almost 12% iron, with 97% of this iron in the ferric form. The coagulant produced was used in the water treatment of lake Guaíba, using as reference the Brazilian standards of potability. The coagulant produced showed to be efficient in the water treatment for public supply purposes.
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Reduction of tetrachloroethylene and trichloroethylene by magnetite revisted

Culpepper, Johnathan D 01 August 2017 (has links)
For this study, we revisited whether the common iron Fe mineral, magnetite Fe3O4 (s), can reduce tetrachloroethylene (PCE) and trichloroethylene (TCE) as discrepancies exist in the literature regarding rates and extent of reduction. We measured PCE and TCE reduction in batch reactors as a function of magnetite stoichiometry (x = Fe2+/Fe3+ ratio), solids loading, pH, and Fe(II) concentration. Our results show that magnetite reacts only slowly with TCE (t1/2 = 7.6 years) and is not reactive with PCE over 150 days. The addition of aqueous Fe(II) to magnetite suspensions, however, results in slow, but measurable PCE and TCE reduction under some conditions. The solubility of ferrous hydroxide, Fe(OH)2(s), appears to play an important role in whether magnetite reduces PCE and TCE. In addition, we found that Fe(OH)2(s) reduces PCE and TCE at high Fe(II) concentrations as well. At certain conditions degradation of the PCE and TCE is enhanced by an unexplored synergistic response from magnetite and ferrous hydroxide iron phases. Our work suggests that measuring dissolved Fe(II) concentration and pH may be used as indicators to predict whether PCE and TCE will be abiotically degraded by groundwater aquifer solids containing magnetite.
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Uptake, Absorption, and Adsorption Kinetics of Ferrous and Ferric Iron in Iron-replete and Iron-deficient Rats

Ummadi, Madhavi 01 May 1994 (has links)
Various concentrations of ferrous and ferric iron solutions were held at room temperature for 60 min before they were assayed for ferrous iron, which may be unstable due to oxidation. The ferrous and ferric solutions (in pH 2 HCl) were maintained as such for 60 min without the use of chelators. There was no significant oxidation of ferrous iron. Also, four different levels of each ferrous and ferric iron were injected into proximal duodenal loops of rat intestine and uptake was determined at four different time intervals. Two iron-replete rats were assigned to each of the treatments. The in situ experiments showed that iron was taken up rapidly from pH 2.0 solutions of ferrous and ferric iron. Maximum amount of iron was taken up in the first 10 min. Uptake of ferrous iron was significantly greater (p < 0.05) than uptake of ferric iron, and there were significant differences in total uptake among the four iron levels used. Uptake, absorption, and adsorption kinetics of both ferrous and ferric iron were determined in situ for both iron-replete and iron-deficient rats. Deficiency caused greater uptake and absorption, confirming a biological adaptation of these processes. Both uptake and absorption were greater for ferrous than for ferric iron and were possibly taken up by different pathways or by a ferrous-ferric pathway with preference for ferrous. Uptake and absorption kinetics were biphasic for both ferrous and ferric iron. The first phase demonstrated saturation kinetics and was followed by a nonsaturable phase at higher concentrations of luminal iron. Iron deficiency altered the uptake and absorption kinetics of ferrous and ferric iron, but not always in a similar manner, suggesting that ferrous and ferric iron were each taken up by a separate pathway. Indications were that enhanced absorption during deficiency was largely due to adaptation of ferric uptake. Iron adsorption was directly proportional to luminal iron concentration, but it was greater for ferric than for ferrous, possibly due to charge interactions. Iron deficiency caused increased adsorption of both ferrous and ferric iron, supporting the notion that adsorption acts to maintain iron in a form available for uptake.
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The sequestration of phosphate by iron phases in the sediments from Lake Rotorua, New Zealand

Mangan, Carmel Mary January 2007 (has links)
A sequential extraction method was used to determine which dominant sedimentary mineral phase was involved in phosphorus retention in the sediments of Lake Rotorua and to verify the importance of iron phases in the role as a phosphorus sink. The observed influence of the experimental conditions upon the extent of phosphate adsorption to various iron phases shows a considerable quantity of phosphorus is present in the reducible phase and in the residual mineral phase. The phosphorus associated with iron(III) oxide phases was released into solution under reducing conditions when ferric iron oxide/oxyhydroxides, including amorphous and poorly crystalline Fe(III) phases, were solubilized. The residual primary and secondary mineral phases remained stable in the sediments until they were exposed to extremely acidic media analogous to strongly reducing conditions. Manganese is not involved in phosphorus retention to the same extent as iron. Aluminium phases present were released from surface complexes with relative ease and also from mineral structures under the prevailing conditions. The results show a strong agreement between aluminium and phosphorus suggesting it is associated with various aluminium phases to some extent. The sediments of Lake Rotorua are rich in organic-bound P which is released when organic material is oxidized under conditions analogous to anaerobic degradation. The degradation of refractory organic material represents a significant source of phosphorus for incorporation into diagenetic minerals forming in oxic and anoxic layers of the sediment. Heavy liquid separation of the sediments concentrated the small quantities of dense minerals into a separate fraction and the presence of iron sulfides could be verified. Three density fractions obtained by this method separated the diatoms (d less than 2.6 g cm-3), the silicates (d greater than 2.6 less than 3.7 g cm-3) and the heavy minerals (d greater than 3.7 g cm-3) present in the sediment sample. In the heavy mineral phase spherulitic framboidal pyrite and rhombohedrial siderite were observed by scanning electron microscopy (SEM). Energy dispersive x-ray fluorescence (XRF) analysis of the framboidal pyrite detected significant fluorescence's for sulphur and iron. The elemental analysis of siderite characterised it as an iron-rich, non-sulfidic particle with no phosphorus fluorescence. Particles were also observed that had a variable morphology to the framboidal pyrite minerals but similar ratio of Fe to S in the XRF spectrum. It is likely they are other stable forms of iron sulfides or pyrites in various stages of diagenetic dissolution. Digestion of the three density fractions shows the heavy mineral phase is significantly enriched in sulfur and in iron confirming the presence of sulfides. The sulfide-forming trace metals are concentrating in the heavy mineral phase but a progressive enrichment of trace metals down core is not found in the results. Many of the trace elements show maximum concentrations in the Tarawera tephra. There is a good agreement between iron and phosphorus in both treatments that implies iron phases are the predominant phosphorus fixers in the sediments of Lake Rotorua. However the identity of the phosphorus sink could not be confirmed by SEM or XRF analysis of the heavy minerals. The most likely explanations for the observed concentrations of iron and phosphorus and enrichment in the heavy mineral fraction are the persistence of the highly insoluble crystalline iron oxyhydroxides (goethite) in reducing sediments or the formation of the reduced iron mineral vivianite. Considering the density of vivianite it would have being taken into the heavy fraction by default which would account for the enrichment demonstrated by the solution analysis.

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