Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Water Res ; 79: 79-87, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25973580

RESUMO

Electrocoagulation (EC) treatment of 100 mg/L synthetic wastewater (SWW) containing humic acids was optimized (achieving 90% CODMn and 80% DOC removal efficiencies), after which real peat bog drainage waters (PBDWs) from three northern Finnish peat bogs were also treated. High pollutant removal efficiencies were achieved: Ptot, TS, and color could be removed completely, while Ntot, CODMn, and DOC/TOC removal efficiencies were in the range of 33-41%, 75-90%, and 62-75%, respectively. Al and Fe performed similarly as the anode material. Large scale experiments (1 m(3)) using cold (T = 10-11 °C) PBDWs were also conducted successfully, with optimal treatment times of 60-120 min (applying current densities of 60-75 A/m(2)). Residual values of Al and Fe (complete removal) were lower than their initial values in the EC-treated PBDWs. Electricity consumption and operational costs in optimum conditions were found to be low and similar for all the waters studied: 0.94 kWh/m(3) and 0.15 €/m(3) for SWW and 0.35-0.70 kWh/m(3) and 0.06-0.12 €/m(3) for the PBDWs (large-scale). Thus, e.g. solar cells could be considered as a power source for this EC application. In conclusion, EC treatment of PBDW containing humic substances was shown to be feasible.


Assuntos
Substâncias Húmicas , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Cor , Eletrólise , Finlândia , Resíduos Industriais , Solo , Águas Residuárias/química
2.
Environ Res ; 132: 197-205, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24813577

RESUMO

Juveniles of Solea senegalensis were fed with commercial pellets under controlled conditions at two environmental Mediterranean temperatures (15 and 20°C) for two months. After this period, the accumulation of essential and non-essential metals and metallothionein (MT) levels was measured in liver and kidney by inductively coupled plasma mass spectrometry (ICP-MS) and pulse polarography, respectively. The bioaccumulation factor (BAF) for selected metals in both tissues was calculated in relation to levels present in the feed. Tissue partitioning (liver/kidney) and molar ratios, considering the metal protective mechanisms: MT and Selenium (Se), were included for evaluating the detoxification capacity of each tissue. Ag, Cd, Cu and Mn were preferentially accumulated in the liver whereas Co, Fe, Hg, Se and Zn were found in larger concentrations in the kidney, and higher temperature enhanced the accumulation of some of them, but not all. MT content in liver, but not in kidney, was also influenced by temperature changes and by length of exposure. The BAF revealed that Cu was taken up mainly by the liver whereas Se was efficiently taken up by both tissues. The high molar ratios of MT and most metals denoted the kidney's remarkable spare capacity for metal detoxification through MT binding. Moreover, the potential protective role of Se was also more evident in kidney as a higher Se:Cd and Se:Ag molar ratios were reached in this organ. In contrast to other fish, the storage of Cd in kidney was particularly low.


Assuntos
Aclimatação , Linguados/metabolismo , Rim/metabolismo , Fígado/metabolismo , Metalotioneína/metabolismo , Metais/metabolismo , Animais , Análise de Alimentos , Temperatura
3.
J Environ Manage ; 128: 413-20, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23792818

RESUMO

An evaluation was made of the performance of a commercial industrial-scale ultrafiltration (UF)-based process for treatment of highly concentrated oily wastewaters. Wastewater samples were gathered from two plants treating industrial wastewaters in 2008, and in 2011 (only from one of the plants), from three points of a UF-based treatment train. The wastewater samples were analyzed by measuring the BOD7, COD, TOC and total surface charge (TSC). The inorganic content and zeta potentials of the samples were analyzed and GC-FID/MS analyses were performed. The removal performances of BOD7, COD, TOC and TSC in 2008 and 2011 for both plants were very high. Initial concentrations of contaminants in 2011 were lower than in 2008, therefore the COD and TSC reductions were also lower in 2011 than three years before. Regardless of the high performance of UF-based processes in both plants, at times the residual concentrations were considerable. This could be explained by the high initial concentrations and also by the presence of the dissolved compounds that were characterized. Linear correlation was observed between COD and TOC, and between COD and TSC. The correlation between COD and TSC could be utilized for process control purposes.


Assuntos
Ultrafiltração , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Carbono/análise , Finlândia , Concentração de Íons de Hidrogênio , Resíduos Industriais , Óleos , Águas Residuárias/análise
4.
Br J Pharmacol ; 170(1): 177-87, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23489295

RESUMO

BACKGROUND AND PURPOSE: Conflicting data have been published on whether histamine is inhibitory to the rewarding effects of abused drugs. The purpose of this study was to clarify the role of neuronal histamine and, in particular, H3 receptors in alcohol dependence-related behaviours, which represent the addictive effects of alcohol. EXPERIMENTAL APPROACH: Alcohol-induced conditioned place preference (alcohol-CPP) was used to measure alcohol reward. Alcohol-induced locomotor stimulation, alcohol consumption and kinetics were also assessed. mRNA levels were quantified using radioactive in situ hybridization. KEY RESULTS: Low doses of H3 receptor antagonists, JNJ-10181457 and JNJ-39220675, inhibited alcohol reward in wild-type (WT) mice. However, these H3 receptor antagonists did not inhibit alcohol reward in histidine decarboxylase knock-out (HDC KO) mice and a lack of histamine did not alter alcohol consumption. Thus H3 receptor antagonists inhibited alcohol reward in a histamine-dependent manner. Furthermore, WT and HDC KO mice were similarly stimulated by alcohol. The expression levels of dopamine D1 and D2 receptors, STEP61 and DARPP-32 mRNA in striatal subregions were unaltered in HDC KO mice. No differences were seen in alcohol kinetics in HDC KO compared to WT control animals. In addition, JNJ-39220675 had no effect on alcohol kinetics in WT mice. CONCLUSIONS AND IMPLICATIONS: These data suggest that histamine is required for the H3 receptor-mediated inhibition of alcohol-CPP and support the hypothesis that the brain histaminergic system has an inhibitory role in alcohol reward. Increasing neuronal histamine release via H3 receptor blockade could therefore be a novel way of treating alcohol dependence.


Assuntos
Etanol/administração & dosagem , Histamina/metabolismo , Histidina Descarboxilase/genética , Receptores Histamínicos H3/metabolismo , Consumo de Bebidas Alcoólicas/metabolismo , Animais , Azepinas/administração & dosagem , Azepinas/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Etanol/farmacocinética , Etanol/farmacologia , Antagonistas dos Receptores Histamínicos H3/administração & dosagem , Antagonistas dos Receptores Histamínicos H3/farmacologia , Liberação de Histamina/fisiologia , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos DBA , Camundongos Knockout , Morfolinas/administração & dosagem , Morfolinas/farmacologia , Atividade Motora/efeitos dos fármacos , Neurônios/metabolismo , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Piridinas/administração & dosagem , Piridinas/farmacologia , RNA Mensageiro/metabolismo , Receptores Histamínicos H3/efeitos dos fármacos , Recompensa
5.
Chemosphere ; 80(5): 570-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20451238

RESUMO

Gilthead sea bream Sparus aurata is the most commercialized Mediterranean aquacultured fish species. Ivermectin has recently (experimentally) started to be used to control ectoparasitic infestations in Mediterranean cultured marine fish. The potential hepatotoxicity of ivermectin was investigated in gilthead sea bream juveniles (35g) following oral administration at the recommended dose of 0.2 mgkg(-1) fish for 10d. Difference Gel Electrophoresis Technology (DIGE) was used to study the effect of this treatment in gilthead sea bream liver protein profile under routine culture conditions. The 2D-DIGE protein maps obtained were analyzed using the DeCyder 6.5 software. The results obtained showed significant changes in the expression of 36 proteins respect to the control group. Among these proteins, six increased in abundance, and 30 decreased. Spot showing differential expression respect to the control were analyzed by mass spectrometry and database search, which resulted in three positive identifications corresponding to hepatic proteins involved in lipid metabolism (apoA-I), oxidative stress responses and energy generation (beta-globin, ATP synthase subunit beta). These proteins have not been previously associated to invermectin effect.


Assuntos
Antiparasitários/toxicidade , Proteínas de Peixes/metabolismo , Ivermectina/toxicidade , Fígado/efeitos dos fármacos , Proteoma/metabolismo , Dourada/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Fígado/metabolismo
6.
Sci Total Environ ; 398(1-3): 48-52, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18420254

RESUMO

The sublethal zinc toxicity to Artemia parthenogenetica as regards the possibility of colonization of zinc polluted salterns by means of cysts has been assessed by a cyst hatching assay and a life table approach. Emergence and hatching at different times as well as the whole hatching profile were taken as end-points for evaluating success of development. Demographic and reproductive parameters calculated according to the Lotka equation were used as an indicator of the chronic toxicity of the population. No adverse effects of waterborne zinc were found on hatching and emergence of cysts of A. parthenogenetica at any of the concentrations tested (0.01 mg/l, 0.1 mg/l, 0.5 mg/l, 1 mg/l, 5 mg/l). Chronic zinc exposure at 0.08 mg/l had detrimental effects on A. parthenogenetica fecundity, as detected by a decrease in the percentage of fertile females, which in turn produces a decrease in r. Chronic toxicity of zinc may be a limiting step for A. parthenogenetica colonization and the establishing of permanent populations in zinc-polluted brine ponds.


Assuntos
Artemia/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , Artemia/fisiologia , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Crescimento Demográfico , Reprodução/efeitos dos fármacos
7.
J Hazard Mater ; 153(1-2): 525-31, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17919813

RESUMO

The purpose of this research was to investigate the effectiveness of short-chain cationic polyelectrolytes of different molecular weights and charge densities in reducing turbidity and selectively removing toxic wood extractives from chemical birch pulp filtrate. The effects of chemical type, dosage and temperature were of interest. An effective performance was achieved with a copolymer of acrylamide and methacrylate of medium molecular weight and medium charge density at 72 degrees C and pH 5-6. The dosage range optimum for reducing the turbidity was 102-142 mg/L. Up to 92% of the wood extractives was selectively removed.


Assuntos
Poliaminas/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Madeira/química , Betula , Floculação , Concentração de Íons de Hidrogênio , Resíduos Industriais , Papel , Polieletrólitos , Temperatura
8.
Water Sci Technol ; 56(11): 123-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18057650

RESUMO

Multimodal zeta potential distribution in chemical birch pulp process water was studied by filtrating the water into fractions and subsequently measuring zeta potential, charge quantity, turbidity and organic substances. Filtrations were made using 12 microm, 1.6 microm, 1.2 microm, 0.45 microm and 0.1 microm membranes. The number of populations with different zeta potentials diminished with filtration. With the unfiltrated water, 12 microm and 1.6 microm filtrates, three or four different zeta potentials were observed. When the filtration was performed with a 1.2 microm membrane or smaller, only two populations of different zeta potentials were detected. The charge quantity steadily approached zero from unfiltrated water towards a 1.6 microm fraction filtrate. After that, it remained constant. Turbidity constantly decreased when using smaller membranes. The amount of wood extractives decreased to half with 0.1 microm filtration. No significant difference in the amount of carbohydrates and lignin between the filtrated fractions and the unfiltrated water was detected. A comparison dealing with particle size analysis between two different apparatuses was also made.


Assuntos
Betula , Resíduos Industriais , Poluentes da Água/análise , Coloides , Filtração , Nefelometria e Turbidimetria , Tamanho da Partícula , Eliminação de Resíduos Líquidos
9.
Environ Int ; 33(4): 532-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17157913

RESUMO

Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel (Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones. No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in muscle and in all instances these levels were lower than the limits established by the Spanish legislation for fish destined for human consumption.


Assuntos
Aquicultura , Enguias , Metalotioneína/análise , Metais/análise , Animais , Guias como Assunto
10.
Arch Environ Contam Toxicol ; 50(1): 111-20, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16237493

RESUMO

The toxicokinetics of cadmium was determined for five populations belonging to four species of Artemia (A. salina, A. parthenogenetica, A. franciscana, and A. persimilis) using a bicompartmental model. The effects of sublethal cadmium concentration on the kinetic parameters in A. parthenogenetica were determined. The BCF values are inversely related to the concentration, as is the uptake rate (ku), whilst the elimination rate (ke) constant seems to be directly related to the exposure concentration. Values corresponding to the rate of metal influx (I) remain relatively constant (0.2477 to 0.4455 microg/g.h) in the concentration range from 0.1 to 1 mg Cd/L, and are higher (1.098 microg/g.h) at an exposure to 10 mg Cd/L. The cadmium accumulation pattern seems well conserved in the genus and is characterized by a fast elimination of the metal with Ke ranging from 0.0050 to 0.0231 h(-1). A. persimilis displays a different model to that corresponding to the other studied species exposed to the same cadmium concentration, presenting a low uptake rate constant (1.0564 mL/g. h) and a low BCF (211.3 mL/g).


Assuntos
Artemia/metabolismo , Cádmio/farmacocinética , Cádmio/toxicidade , Poluentes da Água/farmacocinética , Poluentes da Água/toxicidade , Animais , Artemia/classificação , Artemia/efeitos dos fármacos , Artemia/crescimento & desenvolvimento , Modelos Biológicos
11.
Water Sci Technol ; 50(3): 141-4, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15461408

RESUMO

The decomposition of EDTA and DTPA was studied in simulated chlorine dioxide bleaching conditions. Under the investigated conditions EDTA and DTPA decomposed readily. Accordingly, feeding the chelating agents to the first chlorine dioxide stages (D0) should be reconsidered, when successful metal removal is desired. On the other hand, chlorine dioxide water may be utilized to degrade the chelating agents.


Assuntos
Quelantes/química , Compostos Clorados/química , Desinfetantes de Equipamento Odontológico/química , Ácido Edético/química , Resíduos Industriais , Óxidos/química , Ácido Pentético/química , Eliminação de Resíduos Líquidos/métodos , Papel
12.
Br J Anaesth ; 92(1): 137-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14665566

RESUMO

BACKGROUND: The effect of cardiopulmonary bypass (CPB) on the level of anaesthetic depth has not been studied previously in a randomized way. METHODS: We assessed the effect of CPB on the propofol needed to maintain a fixed bispectral index score, and on the recovery from anaesthesia in 22 patients undergoing coronary artery bypass graft surgery with CPB (on-pump) compared with 18 patients operated on without CPB (off-pump). Anaesthesia was induced and maintained with propofol and alfentanil. Throughout the procedure, the infusion rate of propofol was adjusted to keep the BIS value at 40 +/- 5. RESULTS: With the off-pump technique, the duration of surgery and anaesthetic administration were significantly greater. The need for propofol in proportion to time was exactly the same in both groups. During anaesthesia and the first 3 h thereafter, the BIS recordings were similar in both groups. No differences were detected in the time to awakening or tracheal extubation. CONCLUSIONS: CPB does not affect propofol requirements or immediate postoperative recovery compared with the off-pump technique.


Assuntos
Alfentanil/farmacologia , Anestésicos Combinados/farmacologia , Anestésicos Intravenosos/farmacologia , Ponte Cardiopulmonar , Propofol/farmacologia , Idoso , Idoso de 80 Anos ou mais , Período de Recuperação da Anestesia , Anestésicos Intravenosos/administração & dosagem , Ponte de Artéria Coronária/métodos , Esquema de Medicação , Eletroencefalografia/efeitos dos fármacos , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/métodos , Propofol/administração & dosagem
13.
Scand Cardiovasc J ; 37(4): 211-5, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12944209

RESUMO

OBJECTIVE: To study the inflammatory reaction and myocardial metabolism in off-pump and on-pump coronary artery bypass patients. DESIGN: Fifty coronary artery bypass patients were randomized to off-pump or on-pump operations. Myocardial biopsies were taken to determine myocardial metabolism and inflammation (glutathione (GSH), superoxide dismutase (SOD) and myeloperoxidase (MP)) and plasma samples for indicators of oxidative stress (conjugated dienes (s-BDC), oxidative products of proteins (s-ox-Prot) and low-density lipoprotein (LDL)-total peroxyl radical trapping antioxidant potential (s-TRAP)). RESULTS: s-ox-Prot 10 min was 2.11 +/- 0.75 vs 2.69 +/- 0.60 (p = 0.014), s-TRAP 5 min was 861 +/- 180 vs 969 +/- 192 (p = 0.032) and s-TRAP 10 min 857 +/- 176 vs 985 +/- 166 (p = 0.011), GSH 10 min 0.55 +/- 0.19 vs 0.72 +/- 1.16 (p = 0.007) (off-pump vs on-pump). The monobasic (MB) fraction of the creatinine kinase 24 h after the operation was significantly lower in the off-pump group, 20.5 +/- 24.2 vs 61.8 +/- 84.6 (p = 0.023). CONCLUSION: GSH levels from the biopsies were increased in the perfusion group early in the reperfusion time showing that myocardial tissue was well protected and recovered more rapidly after cross-clamping than after the occlusion of the coronary arteries. However, release of creatinine kinase was lower in the off-pump group showing that cardiopulmonary bypass has more deleterious effects later after the operation.


Assuntos
Ponte de Artéria Coronária , Miocárdio/metabolismo , Idoso , Biomarcadores/sangue , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/cirurgia , Circulação Coronária/fisiologia , Creatina Quinase/metabolismo , Creatina Quinase Forma MB , Eletrocardiografia , Feminino , Glutationa/metabolismo , Humanos , Isoenzimas/metabolismo , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica , Peroxidase/metabolismo , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/metabolismo , Complicações Pós-Operatórias/fisiopatologia , Reoperação , Superóxido Dismutase/metabolismo , Resultado do Tratamento
14.
Chemosphere ; 45(6-7): 881-5, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11695609

RESUMO

The adsorption of Ethylenediaminetetraacetic acid (EDTA) and its metal complexes, Cu, Fe(III), Hg, Mn and Ni, onto lake sediment was studied. The results reveal that EDTA and metal-EDTA complexes, even though being hydrophilic compounds, are indeed adsorbed within one months' contact time to some extent (6.3-24.8%). Less than 10% of Ni-EDTA, Cu-EDTA and EDTA salt was adsorbed, while the mass amount of Mn EDTA, Hg-EDTA and Fe(III)-EDTA found in sediment exceeded 15% after the contact period. Thus, adsorption of metal-EDTA chelates might be a relevant process in their removal from the aquatic environment. The metal-EDTA chelates in aqueous and solid phases were determined by gas chromatography-nitrogen phosphorus detection (GC-NPD) system. The complexes were extracted by phosphate solution prior to analysis. The ability of EDTA to desorb adsorbed heavy metals from sediments is also discussed.


Assuntos
Quelantes/química , Ácido Edético/química , Sedimentos Geológicos/química , Metais Pesados/química , Poluentes da Água/análise , Adsorção , Monitoramento Ambiental
15.
Eur J Cardiothorac Surg ; 20(6): 1183-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11717025

RESUMO

OBJECTIVES: Several risk indices have been developed for the prediction of postoperative mortality and morbidity in coronary artery bypass operations, in which the risk scores are currently recorded as routine praxis. The aim of the present study was to determine whether the risk scores can be used to predict the hospital (LOS) and postoperative (POS) lengths of stay and total costs among coronary artery bypass graft (CABG) patients. METHODS: All first-time CABG patients (n=2104) treated at Helsinki University Central Hospital during 1997-1998 were preoperatively scored using the Cleveland Clinic preoperative model. A multivariate analysis was used to evaluate the effects of the risk scores on the LOS and POS and total costs. RESULTS: The mean preoperative risk score for the patients was 1.69. The increase in preoperative risk score was associated with an increase in the LOS (0.8 days by point), and POS (with 0.55 days by point). An age over 74 years increased the LOS by an extra day. The mean total cost for the CABG procedure was 8750 euros (SD 4430 euros). The costs increased as the risk score increased. Compared with the zero risk score, a score value of 2 was associated with a 1300 euros increase in total cost and a score value of over 6 was associated with an over 7000 euros cost increase. On average, the costs increased by 6980 euros (80%) for one major complication and by 935 euros (10%) in the elderly (>74 years of age). CONCLUSIONS: The results show that increasing risk scores were associated with longer postoperative hospital lengths of stay (POS and LOS) and with increased total costs. An age over 74 years appears to be an independent risk factor in increased POS, LOS and total cost. These results may help to estimate the impact of the preoperative risk profile on the resource requirement in CABG surgery.


Assuntos
Ponte de Artéria Coronária/economia , Custos Hospitalares , Tempo de Internação/economia , Fatores Etários , Idoso , Feminino , Finlândia , Humanos , Masculino , Análise Multivariada , Cuidados Pós-Operatórios
16.
Fresenius J Anal Chem ; 370(8): 1105-8, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11583096

RESUMO

A rapid X-ray fluorescence addition method has been developed for quantification of the technically most important metals in wood pulp matrix (Mn, Fe, and Cu). Pretreatment consisted of just two steps: first, acid was added to the sample to achieve homogeneous distribution of the metals; the pulp was then pressed lightly on to Mylar film. Total analysis time was less than 10 min. The concentration range investigated was up to 15 mg kg(-1) for Mn and up to 5 mg kg(-1) for Fe and Cu. Metal concentrations in Scandinavian pulps are not expected to exceed these amounts. The quantification limit was 2 mg kg(-1) for all three metals. The reproducibilities and repeatabilities were concentration-dependent and varied between 3 and 19% and between 1 and 17%, respectively. The squares of the linear correlation coefficients between measured intensity and added metal concentration were 0.994, 0.950, and 0.932 for Mn, Fe, and Cu, respectively.

18.
Environ Sci Technol ; 35(7): 1379-84, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11348070

RESUMO

The chemical decompositions of beta-alaninediacetic acid (ADA) and diethylenetriaminepentaacetic acid (DTPA) were studied in a pilot-plant flow-through system simulating alkaline (pH 10-11) hydrogen peroxide bleaching environments. The amount of hydrogen peroxide decomposition was evaluated, and the distribution calculation was performed. Under the conditions investigated, ADA was more degradable than DTPA (average residual 71% vs 94%). The decomposition of hydrogen peroxide was not dependent on the chelate; the residual percent of hydrogen peroxide was 40 in both cases.


Assuntos
Ácido Acético/química , Quelantes/química , Peróxido de Hidrogênio/química , Ácido Pentético/química , beta-Alanina/química , Indústrias , Papel , Eliminação de Resíduos
19.
Sci Total Environ ; 267(1-3): 23-31, 2001 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-11286213

RESUMO

The speciations of EDTA and DTPA in process, waste and river waters are modelled and simulated, specifically to the mode of occurrence in the pulp and paper mill effluents and subsequently in receiving waters. Due to relatively short residence times in bleaching process and waste water treatment and slow exchange kinetics, it is expected that the thermodynamic equilibrium is not necessarily reached. Therefore, the initial speciation plays a key role. As such, the simulations have been extended to the process waters of the pulp and paper industry taking into account estimated average conditions. The results reveal that the main species are; Mn and Ca complexes of EDTA and DTPA in pulp mill process waters; Fe(III) and Mn complexes of EDTA and DTPA in waste waters; Fe(III) and Zn complexes of EDTA and DTPA in receiving waters. It is also shown how the increasing concentration of complexing agents effects the speciation. Alkaline earth metal chelation plays a significant role in the speciation of EDTA and DTPA when there is a noticeable molar excess of complexing agents compared with transition metals.


Assuntos
Quelantes/análise , Ácido Edético/análise , Monitoramento Ambiental/métodos , Ácido Pentético/análise , Poluentes Químicos da Água/análise , Quelantes/química , Indústria Química , Simulação por Computador , Ácido Edético/química , Ligantes , Metais Alcalinoterrosos/química , Papel , Ácido Pentético/química , Água/química
20.
Scand Cardiovasc J ; 34(4): 415-20, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10983677

RESUMO

Nitecapone is an antioxidant molecule which has been shown to protect the heart against ischemia-reperfusion injury. We investigated whether a similar effect could be detected on lung graft preservation in a porcine model of single lung transplantation. Donors received either nitecapone or placebo in a modified Euro-Collins pulmonary flush solution. After cold storage for 19 h the left lung was transplanted. Patients in the nitecapone group received a nitecapone infusion during the graft reperfusion. A right-side heart bypass was used to measure flow distribution and pulmonary vascular resistance (PVR) in the recipient's transplanted and native lungs, respectively. Pulmonary vein blood samples were analyzed for blood gases, free radical trapping capacity and diene conjugates. PVR was high in the transplanted lung, which received only 20% of the blood flow. Oxygen tension in the transplanted lung was low (2.3-26.7 kPa). Nitecapone treatment increased the plasma free radical trapping capacity threefold. In spite of this increase in antioxidative capacity nitecapone could not protect the lung against ischemia-reperfusion injury when pulmonary hemodynamics, gas exchange or plasma diene conjugates were used as measures of lung graft function.


Assuntos
Antioxidantes/farmacologia , Catecóis/farmacologia , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Pulmão , Pentanonas/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Modelos Animais de Doenças , Hemodinâmica/efeitos dos fármacos , Infusões Intravenosas , Troca Gasosa Pulmonar/efeitos dos fármacos , Valores de Referência , Sensibilidade e Especificidade , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...