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Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

ROSA, Flavia Troncon; OLIVEIRA-PENAFORTE, Fernanda Rodrigues de; LEME, Izabel de Arruda; PADOVAN, Gilberto Joao; CENEVIVA, Reginald; MARCHINI, Julio Sergio
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.15%
Background: The duodenum and proximal jejunum are excluded after Roux-en-Y gastric bypass but these intestinal sites are where iron and zinc are most absorbed. Therefore, they are among the nutrients whose digestive and absorptive process can be impaired after surgery. The aim of the present study was to investigate the iron and zinc plasma response to a tolerance test before and after bariatric surgery. The study was performed at Sao Paulo University School of Medicine of Ribeirao Preto, Brazil. Methods: In a longitudinal paired study, 9 morbidly obese women (body mass index >= 40 kg/m(2)) underwent an iron and zinc tolerance test before and 3 months after surgery. The iron and zinc levels were determined at 0, 1, 2, 3, and 4 hours after a physiologic unique oral dose. The mineral concentrations in die plasma and 24-hour urine sample were assayed using an atomic absorption spectrophotometer. The anthropometric measurements and 3-day food record were also evaluated. A linear mixed model was used to compare the plasma concentration versus interval after the oral dose, before and after surgery. Results: The pre- and postoperative test results revealed a significantly lower plasma zinc response (P <.01) and a delayed response to iron intake after surgery. The total plasma iron concentration area...

Identificação e quantificação de metais pesados, parasitas e bactérias em esgoto bruto e tratado da Estação de Tratamento de Esgoto de Ribeirão Preto - SP; Identification and quantification of heavy metals, parasites and bacteria in urban wastewater before and after treatment in the Sewage Treatment Station of Ribeirão Preto, S.P

Tonani, Karina Aparecida de Abreu
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/01/2008 PT
Relevância na Pesquisa
36.31%
Nos países em desenvolvimento, onde podemos encontrar áreas urbanas densamente povoadas com precárias condições de saneamento básico, o esgoto sem tratamento é responsável por um grande número de doenças de veiculação hídrica. Além da carga microbiológica (bactérias, vírus, ovos/larvas de helmintos e protozoários), pode também conter diversos poluentes químicos que afetam a saúde humana, dentre eles os metais pesados. Este estudo teve como objetivo avaliar os níveis de metais pesados, bem como identificar e quantificar parasitas e coliformes totais e fecais em efluentes urbanos, antes e após o tratamento de esgoto pelo sistema lodos ativados da Estação de Tratamento de Esgoto de Ribeirão Preto (ETE-RP). A ETE-RP recebe e trata cerca de 57% do esgoto gerado no município de Ribeirão Preto, desde novembro de 2002. O presente estudo foi desenvolvido no Laboratório de Saúde Ambiental da Escola de Enfermagem de Ribeirão Preto/USP, com a colaboração do Laboratório de Pediatria Setor de Metais do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto/FMRP/USP. As amostras foram coletadas durante um ano (de outubro de 2006 a outubro de 2007). No esgoto bruto e tratado foram analisados os seguintes metais: Cd...

Metais pesados em tecidos de Chelonia mydas encalhadas no Litoral do Rio Grande do Sul, Brasil

Silva, Luciana Medeiros
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
POR
Relevância na Pesquisa
36.05%
As atividades humanas afetam a abundância populacional de tartarugas marinhas. A maior parte do impacto sobre essas populações é ocasionada pelo aumento da exploração comercial e industrial das regiões costeiras e oceanos de todo o mundo. As principais ameaças sofridas por estes quelônios estão associadas à alteração de hábitats, ingestão de resíduos sólidos, captura incidental em atividades pesqueiras e contaminação por poluentes químicos. Este trabalho avaliou as concentrações de Cd, Pb e Hg presentes no fígado, músculo peitoral e rim de espécimes de Chelonia mydas encalhadas no litoral norte e médio do RS, sul do Brasil, de outubro de 2009 a abril de 2010. Onze C. mydas foram analisadas, sendo que seis foram coletadas de monitoramentos mensais do Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul e as outras cinco vieram a óbito nas dependências do Centro de Reabilitação de Animais Marinhos, em Imbé, RS. Todos os animais foram inspecionados, necropsiados e os dados biométricos foram obtidos. O fígado, o músculo peitoral e um dos rins foram removidos e armazenados sob congelamento até o momento da análise. Esses tecidos foram desidratados em estufa a 60ºC, digeridos em solução de ácido nítrico e submetidos a um processo específico de digestão em sistema fechado por microondas. As concentrações de Cd e Pb foram determinadas através de espectrofotômetro de absorção atômica por forno de grafite e o Hg foi medido através de espectrofotômetro de vapor a frio. O fígado apresentou as maiores concentrações média de Pb e Hg (0...

Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

Rosa, Flavia Troncon; de Oliveira-Penaforte, Fernanda Rodrigues; Leme, Izabel de Arruda; Padovan, Gilberto Joao; Ceneviva, Reginald; Marchini, Julio Sergio
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 309-314
ENG
Relevância na Pesquisa
46.03%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 0552995-0; Background: The duodenum and proximal jejunum are excluded after Roux-en-Y gastric bypass but these intestinal sites are where iron and zinc are most absorbed. Therefore, they are among the nutrients whose digestive and absorptive process can be impaired after surgery. The aim of the present study was to investigate the iron and zinc plasma response to a tolerance test before and after bariatric surgery. The study was performed at São Paulo University School of Medicine of Ribeirao Preto, Brazil.Methods: In a longitudinal paired study, 9 morbidly obese women (body mass index >= 40 kg/m(2)) underwent an iron and zinc tolerance test before and 3 months after surgery. The iron and zinc levels were determined at 0, 1, 2, 3, and 4 hours after a physiologic unique oral dose. The mineral concentrations in die plasma and 24-hour urine sample were assayed using an atomic absorption spectrophotometer. The anthropometric measurements and 3-day food record were also evaluated. A linear mixed model was used to compare the plasma concentration versus interval after the oral dose, before and after surgery.Results: The pre- and postoperative test results revealed a significantly lower plasma zinc response (P <.01) and a delayed response to iron intake after surgery. The total plasma iron concentration area...

Quantitative analysis of potentially toxic metals in alginates for dental use

Braga, A. S.; Catirse, Alma B.C. Elizaur B.; Vaz, L. G.; Spadaro, A. C C
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 125-130
ENG
Relevância na Pesquisa
46.07%
Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so...

Análise comparativa de métodos para quantificação dos depósitos da pulverização em diferentes alvos

Rezende, Denise Tourino
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: vii, 67 f. : il. color., grafs., tabs.
POR
Relevância na Pesquisa
36.05%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Agronomia (Proteção de Plantas) - FCA; As avaliações dos depósitos da pulverização são utilizadas nas pesquisas como instrumento para desenvolver e melhorar as técnicas de aplicação dos produtos fitossanitários. Considerando essa premissa, o presente trabalho objetivou comparar métodos para quantificação dos depósitos com diferentes marcadores: o corante alimentício Azul Brilhante, os íons Cobre e Sódio, o corante fluorescente Rodamina B e o próprio produto fitossanitário, representado pelo fungicida tebuconazole à 250 g/L (Orius 250 CE), após pulverização em alvos naturais (Phaseolus vulgaris e Brachiaria plantaginea) e em alvos artificiais (papel filtro, papel mata-borrão e lâminas de vidro). As plantas e os alvos artificiais foram pulverizados em um sistema de pulverização com controle de velocidade e pressão de trabalho. Após a pulverização, as plantas foram cortadas junto à superfície do solo, colhidas e colocadas, individualmente, em sacos plásticos devidamente identificados e acondicionados em refrigerador (8±3°C) até o término das aplicações e posterior remoção do marcador. As soluções provindas das lavagens dos alvos foram mantidas em frascos âmbar e também acondicionadas em refrigerador até o momento das análises e obtenção das concentrações dos marcadores em l cm-² e l g-1 de matéria seca. Para quantificação dos respectivos marcadores supracitados foram utilizados os equipamentos: espectrofotômetro Shimadzu UV 1601 PC...

Determination of heavy metals and genotoxicity of water from an artesian well in the city of Vazante- MG, Brazil

Silva, Regildo Márcio Gonçalves da; Amaral, Eni Aparecida do; Oliveira, Vanessa Marques de; Silva, Luciana Pereira
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 6938-6943
ENG
Relevância na Pesquisa
56.07%
The city of Vazante-MG is of great socioeconomic and environmental interest because it is the most important zinc producer district of Brazil. The mineral processing and geochemical processes may determine high concentrations of heavy metals in water intended for human consumption. Thus, the present study aimed to quantify and evaluate the heavy metal genotoxicity of artesian water in the city by Atomic absorption spectrophotometer analysis and testing with the Allium cepa test, respectively. This study reveals a chemical contamination in well water in the city, caused by the presence of heavy metals. Therefore, it can be considered that the high levels of heavy metals found in water samples are correlated with the genotoxic events observed in root cells of A. cepa.

Determination of iron in soils by flow injection atomic absorption spectrometry

Ferreira, M. R. Alexandra; Rangel, António O. S. S.; Lima, José L. F. C.
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
Publicado em //1998 ENG
Relevância na Pesquisa
46.17%
A single-channel flow injection system was optimized for the determination of available iron (Fe) in soil extracts by atomic absorption spectrophotometry. This method of introducing the samples in the spectrophotometer worked particularly well in preventing blockage of the burner head which was observed in the conventional introduction of Fe for its determination by atomic absorption spectrophotometry. The appropriate selection of the manifold parameters, such as injection volume, tube length and flow rate, allowed introduction of any soil extract without requiring any pre-treatment. This system allowed determinations at a detection limit of 0.36 mg L-1 to 5 mg L-1, with an output of 300 determinations per hour. The results obtained for analysis of 15 soil extracts were in good agreement with those provided by the colorimetric method, with average relative deviations of 1.6%. Relative standard deviations of 4.8, 2.5, and 2.3% were obtained for contents of 1.03, 1.85, and 3.99 mg Fe L-1, respectively.

Application of blood cadmium analysis to industry using an atomic fluorescence method.

Fell, G S; Ottaway, J M; Hussein, F E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1977 EN
Relevância na Pesquisa
46.03%
A flame photometric method using atomic fluorescence (AFS) for cadmium (Cd) estimation is described and applied to the measurement of Cd in blood. The AFS system employs a modified, low cost atomic absorption spectrophotometer, with a high intensity Cd light source provided by an electrodeless discharge tube, excited in a thermostatted microwave cavity. The analytical sensitivity of the technique is sufficient to permit dilution (1 in 5) of blood, before aspiration into the air-hydrogen flame. The method is rapid (25 duplicates/hour), and gives acceptable precision (coefficient of variation within batch 2-5%, between batch 8-1%). The method was applied to a reference population and to three different groups of industrial workers. The reference population had a mean blood concentration of 35-1 nmol Cd/litre. Group 1 (general categories of worker) had 65-2 nmol Cd/1, Group 2 (demolition workers), 137-9 nmol Cd/1, and Group 3 (shipbreakers), 105-9 nmol Cd/1. There was a relationship between increases in blood Cd and in blood Pb which was statistically significant for Group 3.

Effect of bis (tributyl tin) oxide on permeability of the blood-brain barrier: a transient increase.

Hara, K; Yoshizuka, M; Doi, Y; Fujimoto, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1994 EN
Relevância na Pesquisa
36.07%
OBJECTIVES--To study the effect of bis (tributyl tin) oxide (TBTO) on permeability of the blood-brain barrier. METHODS--Electron microscopy and an x ray microanalyser with lanthanum chloride as a tracer were used, and blood tin concentrations were determined with an atomic absorption spectrophotometer. Adult male wistar rats received 0.05 ml/kg body weight of TBTO orally. RESULTS--A transient increase in paracellular permeability at the blood-brain barrier was found 2 h after the dose of TBTO. Electron dense lanthanum deposits penetrated tight junctions of the endothelia and permeated the subendothelial space. The x ray microprobe data showed an accumulation of TBTO at the tight junctions at 2 h. Leakage of tracer did not occur at 4 h, but oedematous changes in the surrounding glial cells were prominent between 4 and 8 h and had almost returned to normal by 24 h. By atomic absorption analysis, it was seen that blood tin concentrations rapidly increased at 1 h and rose to a maximum peak at 8 h, then gradually decreased to reach zero at 24 h. CONCLUSIONS--Accumulated TBTO at tight junctions could have caused the temporary replacement of calcium ion by tin, which induces a transient increase in paracellular permeability throughout the blood-brain barrier.

Study on arsenic level in public water supply of Delhi using hydride generator accessory coupled with atomic absorption spectrophotometer

Lalwani, Sanjeev; Dogra, T. D.; Bhardwaj, D. N.; Sharma, R. K.; Murty, O. P.
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /03/2006 EN
Relevância na Pesquisa
66.23%
Exposure to arsenic has been associated with several health hazards. Worldwide the main reason for chronic human intoxication with arsenic is intake of contaminated drinking water. Air acetylene type of atomic absorption spectrophotometer in combination with hydride generator accessory was used to analyze arsenic level in 25 water samples collected from 25 booster pumping stations and 313 water samples collected from tap water supply of 62 areas of Delhi. Results were analyzed using SPSS and Barlett’s Chi Square Test. Mean arsenic level detected in water samples collected from booster pumping stations was 0.00976 ppm (Range 0.000–0.017 ppm, Standard Deviation 0.006 and Standard error of Mean 0.00118). Maximum arsenic level (0.017 ppm) was found in water samples of booster pumping stations of Mehrauli, Punjabi Bagh and Ramjas Road. Mean arsenic level detected in samples collected from tap water supply was 0.013 ppm (Range 0–0.0430 ppm, Standard Deviation 0.00911 and Standard error of Mean 0.000515). In water samples of 42 areas arsenic level detected was exceeding WHO/EPA permissible limit of 0.01 ppm (10 ppb). The mean arsenic level detected in water samples of booster pumping station was within WHO/EPA permissible limit while mean arsenic level detected in tap water samples was marginally higher. Mixing of ground water and contamination through broken or leaking channel could be the possible reason of higher arsenic level in tap water. Continuous monitoring of quality of drinking water is required particularly in view of water contamination caused by industrial waste and uncontrolled ground water extraction.

Study on arsenic level in ground water of Delhi using hydride generator accessory coupled with atomic absorption spectrophotometer

Lalwani, Sanjeev; Dogra, T. D.; Bhardwaj, D. N.; Sharma, R. K.; Murty, O. P.; Vij, Aarti
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /07/2004 EN
Relevância na Pesquisa
66.23%
Surveillance of drinking water is essentially a health measure intended to protect the public from water borne diseases. Hydride generator accessory coupled with atomic absorption spectrophotometer was used to analyze arsenic level in 49 ground water samples collected from different areas of Delhi. Arsenic level in ground water samples was in the range of 0.0170 to 0.100 ppm (Mean-0.0431, Standard Deviation-0.0136, Std. error of Mean-0.00194) with minimum concentration at Raney Well No. 7 (0.0170 ppm) and maximum at Kotla Mubarak Pur (0.100 ppm). Arsenic containing sediments and percolation of chemicals into soil as the result of dumping of garbage rich in chemicals into open landfills could be the possible source of arsenic in ground water of Delhi. Extensive survey and continuous monitoring is required to be made to assess the magnitude of problem and earlier intervention.

Remoção de cromo (vi) e carbono orgânico total em biorreatores híbridos sequenciais

Brandão, Camilo Aurélio
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
45.98%
O presente trabalho avaliou o desempenho do sistema de biorreatores híbridos sequenciais, sem aeração e com aeração intermitente, na remoção de Cromo (VI), Cromo Total, Carbono Orgânico Total (COT) de um meio sintético (afluente) contendo Cr (VI). A Demanda Química de Oxigênio (DQO) e a concentração de biomassa também foram monitoradas. Como inóculo nos biorreatores, foram utilizadas culturas mistas de micro-organismos originária de lodo industrial, previamente adaptadas, e como fonte de Cr (VI), o dicromato de potássio (K2Cr2O7). Incialmente foi realizado um teste em branco, antes da adição de cromo ao sistema, com o propósito de se verificar a influência da presença do metal na remoção de COT. Foram realizados três ensaios cinéticos, nas concentrações iniciais de cromo hexavalente de 80, 120 e 150 mg/L. Após cada cinética, avaliou-se a remoção durante a regeneração dos biorreatores, com o mesmo efluente, porém sem cromo. A concentração de Cr (VI) foi determinada pelo método colorimétrico utilizando difenilcarbazida 3500-Cr D, conforme APHA (2005). A concentração de Cromo Total foi medida em Espectrofotômetro de absorção atômica AA-7000 Shimadzu. A caracterização em relação ao COT foi realizada pela técnica de combustão catalítica a alta temperatura...

Avalia??o neurocomportamental da exposi??o cr?nica ao Merc?rio inorg?nico na mem?ria social e mem?ria emocional de ratos wistar machos adultos

FERNANDES, Rafael Monteiro
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
36.07%
O merc?rio inorg?nico ? facilmente absorvido por ingest?o ou via cut?nea. Entretanto, uma quantidade relativamente pequena de Hg2+ atravessa a barreira hematoencef?lica ou as membranas biol?gicas, sendo em ratos adultos, o transporte axonal retr?grado a ?nica via para a absor??o de Hg2+ por neur?nios, apresentando um forte potencial neurot?xico. Desta forma, o presente estudo objetivou investigar os efeitos da exposi??o cr?nica ao cloreto de merc?rio em mem?ria social e emocional de ratos adultos. Para isso utilizou-se ratos Wistar, machos (n=40), com 5 meses de idade, distribu?dos em dois grupos, um dos quais foi exposto ao Cloreto de Merc?rio (HgCl2) via oral, por gavagem intra-g?strica (0,375mg/Kg), durante 45 dias. O outro grupo, denominado grupo controle (n=20) recebeu ?gua destilada por gavagem. Foram utilizados os seguintes testes comportamentais: teste do campo aberto, teste de reconhecimento social para avalia??o de mem?ria social; o Teste do Labirinto em T Elevado (LTE) foi usado para avaliar o aprendizado do estado de esquiva e as mem?rias de curta e longa-dura??o. Ap?s a finaliza??o dos testes, os animais foram sacrificados para a dosagem do merc?rio total no hipocampo e atrav?s de um Espectrofot?metro de Absor??o At?mica. Os resultados revelaram que os animais submetidos ? exposi??o ao cloreto de merc?rio n?o manifestaram d?ficits em atividade explorat?ria. Nos dados do Teste de Reconhecimento Social...

Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry

Nguyen, K.; Lewis, D.; Jolly, M.; Robinson, J.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2004 EN
Relevância na Pesquisa
76.17%
The steps of the standard method to determine soluble aluminium concentration are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49–61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium concentration of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.; K.L. Nguyen, D.M. Lewis, M. Jolly and J. Robinson

Hydroxyl and calcium ions diffusion from endodontic materials through roots of primary teeth - in vitro study

Nunes,Ana Cristina Gerent Petry; Rocha,Maria José de Carvalho
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2005 EN
Relevância na Pesquisa
56.07%
The purpose of this research was to evaluate the diffusion of calcium (Ca+2) and hydroxyl (OH-) ions from materials with a calcium hydroxide base - Ca(OH)2 through the intact roots of deciduous teeth. This diffusion of ions is important for periapical healing. Forty-six deciduous teeth were selected and instrumented to their working length with #40 files. The teeth were washed during cleaning and shaping with a 1% sodium hypochlorite (NaOCl) solution. The canals were dried with paper points. The teeth were divided into 4 groups based on the sealer type, with 10 specimens in each group. A fifth group of 6 teeth without sealer constituted the control group. The materials used as sealers were: Ca(OH)2 paste associated to propylene glycol (CaPE) thickened at the proportion of 2:1 w/v; UFSC (Federal University of Santa Catarina) paste - a mixture of 0.3g of zinc oxide with 0.3g of Ca(OH)2 with 0.2ml of olive oil 1:1 w/w; Vitapex® and Sealapex®. The coronal access was sealed with a glass ionomer after the root had been filled with each sealer. A one-third apical surface and foramen was hard-pressed with Araldite®. The teeth were stored individually in flasks containing saline solution at 37ºC and 100% humidity. The OH- and Ca+2 ions diffusion levels were determined using a pH meter and an atomic absorption spectrometer. Data were collected at 48 hours and at intervals of 7...

Determination of copper in different chloroplast preparations

Arellano, Juan B.; Barón Ayala, Matilde; Chueca, Ana; Lachica López, Manuel
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 145829 bytes; application/pdf
ENG
Relevância na Pesquisa
56.07%
The determination of total Cu is not often correlated with states of deficiency in plant material. This fact makes it necessary to look for biologically active Cu. Suspensions of thylakoid membranes and photosystem II particles, properly diluted with 13 mM nitric acid, were used for this purpose. The presence of a minute quantity of an antifoaming agent, such as 1-octanol, is essential when an aliquot of the slurry is injected into the graphite furnace of the atomic absorption spectrophotometer. Good agreement was obtained between our results and those obtained by a classical dry combustion method. Reproducibility was better than 5% when expressed as relative standard deviation.; Ministerio de Educación y Ciencia (Spain); Peer reviewed

Avaliação in vitro da difusão de íons Ca+2 e OH- de materiais endodônticos em dentes decíduos; Hydroxyl and calcium ions diffusion from endodontic materials through roots of primary teeth - in vitro study

Nunes, Ana Cristina Gerent Petry; Rocha, Maria José de Carvalho
Fonte: Universidade de São Paulo. Faculdade de Odontologia de Bauru Publicador: Universidade de São Paulo. Faculdade de Odontologia de Bauru
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/06/2005 ENG
Relevância na Pesquisa
56.07%
O objetivo desta pesquisa foi avaliar a difusão de íons Ca+2 e OH- de materiais endodônticos a base hidróxido de cálcio - Ca(OH)2, através da raiz intacta de dentes decíduos. 46 dentes decíduos foram selecionados e instrumentados em seu comprimento de trabalho até a lima # 40, e irrigados durante o preparo com solução de hipoclorito de sódio 1%, e secos com cones de papel absorvente. Os dentes foram separados em 4 grupos de 10 dentes cada conforme o material obturador, e um grupo controle com 6 dentes permaneceu vazio. Os materiais utilizados como obturadores foram: pasta de Ca(OH)2 associada ao propilenoglicol espessada (CaPE) na proporção de 0,4g de pó para 0,2ml de líquido; pasta UFSC, mistura de 0,3g de pó de óxido de zinco com 0,3g de pó de Ca(OH)2 associado a 0,2ml de óleo de oliva; Vitapex® e Sealapex®. Após a obturação, todos os dentes tiveram o forame e terço apical selado com Araldite® e o acesso coronal selado com ionômero de vidro, permanecendo em frascos individuais com a raiz submersa em solução fisiológica, em estufa a 37ºC em 100% de umidade. A análise da difusão de íons OH- e Ca+2 foi realizada por meio de um pHmetro calibrado e um espectrômetro de absorção atômica, respectivamente...

Taxa de chumbo em amostra de voluntários "não expostos" habitantes da Grande São Paulo - Brasil; The level of lead in blood samples from non-exposed volunteer residents of Great S. Paulo (Brazil)

Nogueira, Diogo Pupo; Colacioppo, Sérgio; Souza, José Maria Pacheco de; Pezza, Cleide Bernardes; Souza, Marlene Lopes Assis de; Gomes, Jorge da Rocha
Fonte: Universidade de São Paulo. Faculdade de Saúde Pública Publicador: Universidade de São Paulo. Faculdade de Saúde Pública
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/06/1979 POR
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45.98%
Através de um espectrofotômetro de absorção atômica foram pesquisados os níveis de chumbo no sangue de 315 voluntários de ambos os sexos (167 do sexo masculino e 148 do feminino) que não revelaram exposição ocupacional a esse metal. Foi encontrado um valor médio de 17,2 µg/100 ml para o sexo masculino e 14,2 µg/100 ml para o sexo feminino. Sugere-se a execução de novos estudos que envolvam populações definidas e amostragem probabilística.; The level of lead in the blood of 315 volunteers (167 male and 148 female) who had not been exposed professionally to the metal, was measured by the atomic absortion spectrophotometer method. The average value was 17.2 µg/100 ml in the males and 14.2 µg/100 ml in the females. It is suggested that new studies should be carried out, using a definite population and a probabilistic sampling.

OCCURRENCE OF LEAD AND CADMIUM IN SLAUGHTERED CHICKEN LIVER IN RIO DE JANEIRO (BRAZIL); OCORRÊNCIA DE CHUMBO E CÁDMIO EM FÍGADO DE AVES ABATIDAS NO RIO DE JANEIRO*

BASSO, LÍDIA MARIA; Universidade Federal de Fortaleza; LASZLO, HERTA; Universidade Federal de Fortaleza
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 25/08/2009 POR
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The main aim of this work was to evaluate the rate of heavy metals contamination in chicken marketed in Rio de Janeiro, by determining its lead and cadmiun contents. Simultaneous ly i t was checked if a less precise and cheapper atomic absorption spectrophotometer could be used in routine analysis of meat products and if dry ashing technique along with ashing aid in the sample destruction for the atomic absorption analysis of these two metals could be used, in order to avoid employing importated acids of high purity which are very expensive and difficult to get. The results showed that the chicken that was analysed by this method had no detectable traces of lead and cadmiun, there were no traces above the background noise of 0,4 ppm for Pb and 0,04 ppm for Cd. (The Brazilian law allows up to 8 and 1 ppm of Pb and Cd, respectively). We have concluded that the dry ashing technique with ashing aid is applicable in lead analysis of meat products however not so reliable for cadmiun analysis. A review of the literature about toxicological problems caused by these two metals was also made.; O presente trabalho teve por objetivo precípuo avaliar o grau de contaminação dos frangos comercializados no Grande Rio por metais pesados...