9 research outputs found

    Moringa oleifera Lam. seeds as a natural solid adsorbent for removal of AgI in aqueous solutions

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    This work describes the sorption potential of Moringa oleifera seeds for the decontamination of AgI in aqueous solutions. Infrared spectroscopy was used for elucidating possible functional groups responsible for uptaking AgI. Sorption studies using AgI standard solutions were carried out in batch experiments as functions of adsorbent mass, extraction time, particle size and pH. The AgI was quantified before and after the removal experiments using flame atomic absorption spectrometry. Furthermore, based on adsorption studies and adsorption isotherms applied to the Langmuir model, it was possible to verify that M. oleifera seeds present a high adsorption capacity. The optimum conditions were: 2.0 g of adsorbent with particle size of 75-500 µm, 100 mL of 25.0 mg L-1 AgI, extraction time of 20 min and pH at 6.5. The results show that Moringa oleifera seeds can be used for removing AgI in aqueous solutions

    Chelating agents to solubilize heavy metals from Oxisols contaminated by the addition of organic and inorganic residues Uso de quelantes na solubilização de metais pesados de Latossolos contaminados pela adição de resíduos orgânico e inorgânico

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    Phytoremediation is an attractive technique for soils contaminated with heavy metals, especially in conjunction with chelating agents to assist metal phytoextraction. Nevertheless, their studies in Brazil are rare. Thus, the objective of the present work was to evaluate the efficiency of the chelating agents EDDS and EDTA for the solubilization of heavy metals from two Oxisols contaminated by organic sources in Jaguariúna (LVJ) and inorganic sources in Paulínia (LVP), São Paulo State, Southeastern Brazil. First, the soil samples were fractionated and the DTPA method was used to quantify heavy metals available forms. The results indicated that the metals were highly available in the soil fractions and could be solubilized by the chelating agents. The soil was suspended for 24 h in a chelating agent solution (EDTA or EDDS) at rates of 0, 250, 500 and 750 mg kg-1 of soil. The concentration of solubilized heavy metals was determined in the resulting solution. The extent of metal solubilization varied according to soil type, the chelating agent added and the specific metal. The amount of iron solubilized, as compared to the total iron (LVJ) was 11% (EDTA) and 19% (EDDS). EDDS solubilized more Cu than EDTA in both soils but more Ni in LVJ, while EDTA solubilized more Zn in both soils but more Cd in LVP. Both EDTA and EDDS may be useful for phytoextraction from soils, although the iron content is an important factor regarding the phytoextraction of heavy metals with chelating agents in Oxisols.<br>A fitoextração tem sido uma opção atrativa para remediar solos contaminados com metais pesados, principalmente quando associada à aplicação de quelantes ao solo, embora no Brasil seus estudos sejam muito incipientes. Portanto, o objetivo deste trabalho foi avaliar a eficiência dos quelantes EDTA e EDDS na solubilização de metais pesados em Latossolos contaminados por Cu, Zn, Cd e Ni, cujas fontes de contaminação foram: orgânica em Jaguariúna (LVJ) e inorgânica em Paulínia (LVP). Antes da solubilização dos metais com os quelantes as amostras de solo foram submetidas ao fracionamento seqüencial e à extração dos metais pesados pelo método do DTPA. Ainda, as amostras dos dois solos foram agitadas com as soluções dos quelantes, por 24 h, usando as seguintes doses: 0, 250, 500 e 750 mg kg-1 de solo, realizando-se a determinação dos metais pesados no sobrenadante. Tanto a extração com DTPA como o fracionamento seqüencial indicaram que os metais estavam nas frações disponíveis que poderiam ser solubilizados pelos quelantes. As quantidades solubilizadas de Cu, Fe, Zn e Ni variaram em função do tipo de solo, dos quelantes e das doses aplicadas. A solubilização do Fe em relação ao seu teor total no LVJ foi de 11% (EDTA) e 19% (EDDS). O EDDS solubilizou mais Cu em ambos os solos e Ni no LVJ, enquanto o EDTA apresentou maior solubilização do Zn também em ambos os solos e do Cd no LVP. Portanto, a utilização de tais complexantes pode ser promissora na fitoextração de metais em solos, mas a avaliação da concentração de Fe no solo torna-se importante quando se utiliza a técnica de fitoextração assistida por quelantes para remediar Latossolos contaminados com metais

    Fatores de risco associados à mortalidade de recém-nascidos de muito baixo peso na cidade de Botucatu, São Paulo, no período 1995-2000 Risk factors for mortality in very low birth-weight infants in the city of Botucaty, State of São Paulo, during the period 1995-2000

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    OBJETIVOS: avaliar as práticas assistenciais, a ocorrência de doenças, a mortalidade durante a hospitalização e os fatores associados em recém-nascidos prematuros de muito baixo peso (PT-MBP). MÉTODOS: estudo transversal comparando dois períodos: 1995-1997 e 1998-2000 e envolvendo todos os PT-MBP nascidos vivos (n= 451), em um centro perinatal, em Botucatu, São Paulo, Brasil. Os fatores de risco pré-natal e pós-natal foram submetidos a análise multivariada. RESULTADOS: a mortalidade diminuiu de 36,2% para 29,5%. A sobrevida melhorou e foi superior a 50% a partir de 28 semanas e de 750 g de peso. O uso de corticosteróide antenatal aumentou de 25% para 42%, o surfactante exógeno de 14% para 28%, com redução na incidência e gravidade da síndrome do desconforto respiratório. A regressão logística mostrou que a síndrome do desconforto respiratório grave, Odds ratio=18, e a sepse precoce, Odds ratio=2,8, foram importantes fatores de risco para morte em 1995-1997. No período de 1998-2000, a sepse precoce e tardia, Odds ratio=10,5 e 12, respectivamente, aumentaram o risco de morte. CONCLUSÕES: a melhora na assistência perinatal diminuiu a mortalidade do PT-MBP. O aumento na exposição antenatal ao corticosteróide diminuiu a gravidade da síndrome do desconforto respiratório. Em 1998-2000, a sepse foi o único fator de risco para morte.<br>OBJECTIVES: to evaluate perinatal care, the incidence of diseases, and mortality during hospitalization and associated risk factors in very low birth-weight infants (VLBW). METHODS: a cross sectional survey comparing two periods: 1995-1997 and 1998-2000, including all live-born VLBW preterm infants (n= 451), delivered at a level III perinatal center in the city of Botucatu, State of São Paulo, Brazil. The antenatal and postnatal risk factors were analyzed using multivariable techniques. RESULTS: mortality decreased from 36.2% to 29.5%. The survival of infants 750 g, and 28 weeks' gestation improved and was higher than 50%. The use of antenatal corticosteroid increased from 25% to 42%, surfactant therapy from 14% to 28%, and the incidence and severity of respiratory distress syndrome decreased. Regression analysis showed that severe respiratory distress syndrome (Odds ratio= 18) and early-onset sepsis (Odds ratio=2.8) were important risk factors for death in 1995-1997. During 1998-2000 early- and late-onset sepsis (Odds ratio=10.5 and 12 respectively) increased the risk of death. CONCLUSIONS: the improvement in perinatal care has reduced the mortality of VLBW infants. The increase in antenatal corticosteroid exposure has reduced the severity of respiratory distress syndrome. In 1998-2000, sepsis was the only risk factor associated with death

    CCR2 plays a protective role in Rocio virus–induced encephalitis by promoting macrophage infiltration into the brain

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    Rocio virus (ROCV) is a highly neuropathogenic mosquito-transmitted flavivirus responsible for an unprecedented outbreak of human encephalitis during 1975-1976 in Sao Paulo State, Brazil. Previous studies have shown an increased number of inflammatory macrophages into the central nervous system (CNS) of ROCV-infected mice, implying a role for macrophages in the pathogenesis of ROCV. Here, we showed that ROCV infection results in increased expression of C-C chemokine ligand 2 (CCL2) in the blood and in infiltration of macrophages into the brain. Moreover, we showed using C-C chemokine receptor 2 (CCR2) knockout mice that CCR2 expression was essential for macrophage infiltration in the brains during ROCV infection and that the lack of CCR2 resulted in increased disease severity and mortality. Thus, our findings show the protective role of CCR2-mediated infiltration of macrophages in the brain during ROCV infection
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