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1.
Rehabilitación (Madr., Ed. impr.) ; 57(1): 100732-100732, Ene-Mar. 2023. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-214200

RESUMO

Introducción: La actividad física es esencial en la población con artrosis, sin embargo, el confinamiento durante la pandemia por COVID obligó al cambio en los estilos de vida. Se llevó a cabo un estudio observacional y descriptivo con el objetivo de evaluar el ejercicio físico realizado en personas con patología osteoarticular degenerativa (POD) durante la pandemia por COVID-19. Material y métodos: Se realizó una encuesta telefónica a personas mayores de 60 años con POD atendidos previamente en el Hospital Central de la Cruz Roja, valorando el ejercicio físico durante el confinamiento por pandemia COVID-19. Se analizaron las variables (tiempo de ejercicio físico, causas si el ejercicio fue reducido, y la intensidad de dolor) y se compararon con la situación previa al confinamiento domiciliario. Resultados: Se incluyeron un total de 33 pacientes (ocho hombres, 25 mujeres), con una edad media de 75,6 años. La poliartrosis fue el diagnóstico más frecuente. El 51,5% realizaban la misma cantidad de ejercicio físico, el 21,21% realizaban más y 24,2% menos que antes. Solo el 6,1% realizaba más de una hora al día de actividad. El 36,4% tenían más dolor que previamente. Conclusiones: Aunque existe una alta adherencia a los ejercicios aprendidos en el servicio de rehabilitación, el confinamiento por COVID-19 ha tenido un efecto negativo en el nivel de ejercicio realizado por los pacientes con POD. Es recomendable incentivar el ejercicio físico durante períodos de confinamiento.(AU)


Introduction: Physical activity is essential in the osteoarthritis population, however, confinement during the COVID pandemic forced lifestyle changes. An observational and descriptive study was conducted to assess physical exercise in people with degenerative osteoarticular disease (DOD) during the COVID-19 pandemic. Material and methods: A telephone survey was conducted among people over 60 years of age with DOD previously treated at the Hospital Central de la Cruz Roja, assessing physical exercise during the COVID-19 pandemic confinement. The variables (time of physical exercise, causes if exercise was reduced, and pain intensity) were analysed and compared with the situation prior to home confinement. Results: A total of 33 patients (8 men, 25 women) were included, with a mean age of 75.6 years. Polyarthrosis was the most frequent diagnosis. 51.5% performed the same amount of physical exercise, 21.21% performed more and 24.2% less than before. Only 6.1% performed more than 1 h a day of activity. 36.4% had more pain than previously. Conclusions: Although there is a high adherence to the exercises learned in the rehabilitation service, COVID-19 confinement has had a negative effect on the level of exercise performed by POD patients. It is advisable to encourage physical exercise during periods of lockdown.(AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Confinamento Controlado , Exercício Físico , Artropatias , Pandemias , Infecções por Coronavirus , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Medição da Dor , Reabilitação , Espanha , Inquéritos e Questionários , Epidemiologia Descritiva , Estudos Transversais
2.
Rehabilitacion (Madr) ; 57(1): 100732, 2023.
Artigo em Espanhol | MEDLINE | ID: mdl-35545482

RESUMO

INTRODUCTION: Physical activity is essential in the osteoarthritis population, however, confinement during the COVID pandemic forced lifestyle changes. An observational and descriptive study was conducted to assess physical exercise in people with degenerative osteoarticular disease (DOD) during the COVID-19 pandemic. MATERIAL AND METHODS: A telephone survey was conducted among people over 60 years of age with DOD previously treated at the Hospital Central de la Cruz Roja, assessing physical exercise during the COVID-19 pandemic confinement. The variables (time of physical exercise, causes if exercise was reduced, and pain intensity) were analysed and compared with the situation prior to home confinement. RESULTS: A total of 33 patients (8 men, 25 women) were included, with a mean age of 75.6 years. Polyarthrosis was the most frequent diagnosis. 51.5% performed the same amount of physical exercise, 21.21% performed more and 24.2% less than before. Only 6.1% performed more than 1 h a day of activity. 36.4% had more pain than previously. CONCLUSIONS: Although there is a high adherence to the exercises learned in the rehabilitation service, COVID-19 confinement has had a negative effect on the level of exercise performed by POD patients. It is advisable to encourage physical exercise during periods of lockdown.


Assuntos
COVID-19 , Osteoartrite , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Controle de Doenças Transmissíveis , Exercício Físico , Pandemias , SARS-CoV-2
3.
J Environ Manage ; 255: 109927, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32063308

RESUMO

This study was aimed at the degradation of sulfonamides (SNs) via oxidation with Fe(VI). The reaction kinetics, identification of degradation byproducts and their toxicity were investigated. The pH solution and Fe(VI) loading had significant effects on the degradation of the sulfonamides. The maximum degradation rate occurred at pH 3.0 with a 6:1 ratio Fe(VI): sulfonamide, obtaining 100% degradation of 15 mg L-1 SN within 5 min. Although Fe(VI) also showed an appreciable reactivity towards SNs (kapp = 9.85-19.63 × 102 M-1 s-1) at pH 7. The influence of solution pH on the values of kapp can be explained considering the specific reaction between Fe(VI) and SNs. Degradation rates are also influenced by the presence of inorganic ions in different water matrixes. For this reason, ions present in groundwater enhanced the SNs degradation through a synergistic effect among carbonates, sulfates and Fe(VI). Degradation byproducts identified, through UPLC analysis, allowed us to proposed three degradation pathways depending on pH. At acid pH there is a cleavage of C-S and S-N bonds. At neutral pH nitroso and nitro-derivates are formed. At basic pH hydroxylation is the main reaction. The cytotoxicity assay of HEK-293 and J774 cell lines exposed to Fe(VI) indicated that transformation byproducts had a lower toxicity than SNs as baseline products. Accordingly, this research suggests that Fe(VI) can act as a chemical oxidant to remove SNs antibiotics and it can be used to treat antibiotic pollution in wastewater.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Ferro , Cinética , Oxirredução , Sulfonamidas
4.
RSC Adv ; 10(18): 10646-10660, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35492913

RESUMO

A controlled synthesis of methotrexate (MTX) silver nanoparticles (AgNPs-MTX) using borohydride and citrate as reduction and reduction/capping agents, respectively, was performed in order to obtain AgNPs-MTX conjugates with a narrow size distribution. Their characterization showed polydispersed spherical shape nanoparticles with a mean size around 13 nm and distribution range between 7-21 nm. The presence of MTX was confirmed by FTIR and EDX analysis. Spectroscopic determinations suggest the chemisorption of MTX through a carboxylic group (-COOH) onto AgNPs via the exchange with a citrate molecule. Drug loading capacities calculated for AgNPs synthesized using different amounts of MTX were 28, 31 and 40%. In vitro drug release tests depicted similar release profiles for all conjugated amounts releasing between 77 to 85% of the initial MTX loaded into the AgNPs. With respect to free MTX, the addition of the nanocarrier delayed its release and also changed its pharmacokinetics. Free MTX is released after 3 hours following a first order kinetic model, whereas in the presence of AgNPs, a fast initial release is observed during the first 5 hours, followed by a plateau after 24 hours. In this case, AgNPs-MTX fitted a Higuchi model, where its solubilization is controlled by a diffusion process. Results obtained from flow cytometry of different cell lines treated with AgNPs-MTX demonstrated the combined anticancer effect of both reagents, decreasing the percentage of living cells in a colon cancer cell line (HTC-116) down to 40% after 48 hours of exposure. This effect was weaker but still significant for a lung cancer cell line (A-549). Finally, a zebrafish assay with AgNPs-MTX did not show any significant cytotoxic effect, confirming thereby the reduction of systemic drug toxicity achieved by coupling MTX to AgNPs. This observed toxicity reduction in the zebrafish model implies also a probable improvement of the usage of AgNPs-MTX in chemotherapy against human cancers.

5.
J Environ Manage ; 257: 109973, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31868639

RESUMO

The objective of this study was to analyse the effectiveness of advanced oxidation processes (AOPs) with Solar and UV radiation (UV/H2O2, UV/K2S2O8) for the degradation of hydrochlorothiazide (HCTZ), a widely used diuretic drug, in aqueous solution focusing on the influence of four experimental parameters: initial concentration of HCTZ, solution pH, nature of the water matrix, and initial concentration of radicals. The obtained results showed that using both kinds of direct photolysis (UV and Solar), the percentage of degraded HCTZ was low, but there was a decrease in the degradation rate favored by the increase of the initial concentration of this pollutant. In addition, the degradation rates were higher at acid pHs. With regard to the nature of water, the degradation rate varied in the order: ultrapure > superficial > tap water. This is due to the presence of organic and inorganic matter (bicarbonates, nitrates, and chlorides) in surface and tap water, that react with the radicals generated, which reduces the availability of radical species, generating competitive kinetics. The presence of radical-promoter species increased the degradation rate of the pollutant, reaching a degradation of 100% of HCTZ after 20 min of treatment. The results obtained point out that the degradation rate was higher in the presence of HO radicals. This behavior was attributed to the higher oxidation power of HO versus radicals. The determination of the degradation by-products led to structures very similar to the parent compound. For example, the corresponding hydroxylated dechlorinated derivative of HCTZ was found in all the systems used. The cytotoxicity test showed that these byproducts have a lower toxicity than the original product. Finally, the economic viability study confirmed that the UV/K2S2O8 system has the lowest cost.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Diuréticos , Hidroclorotiazida , Peróxido de Hidrogênio , Cinética , Oxirredução , Fotólise , Raios Ultravioleta
6.
J Environ Manage ; 253: 109731, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31665690

RESUMO

This study proposes the use of new materials based on core-shell structure magnetic microparticles with Ag0 (Ag(0)-MPs) on their surface to remove bromides and chlorides from waters intended for human consumption. Hydrogen peroxide was used as oxidizing agent, Ag(0)-MPs is thereby oxidized to Ag (I)-MPs, which, when in contact with Cl- and Br- ions, form the corresponding silver halide (AgCl and AgBr) on the surface of Ag-MPs. The concentration of Cl- and Br- ions was followed by using ion selective electrodes (ISEs). Silver microparticles were characterized by high-resolution scanning electron microscopy and X-ray photoelectron spectroscopy, while the presence of AgCl and AgBr on Ag-MPs was determined by microanalysis. We analyzed the influence of operational variables, including: hydrogen peroxide concentration in Ag-MP system, medium pH, influence of Cl- ions on Br- ion removal, and influence of tannic acid as surrogate of organic matter in the medium. Regarding the influence of pH, Br-and Cl- removal was constant within the pH range studied (3.5-7), being more effective for Br- than for Cl- ions. Accordingly, this research states that the system Ag-MPs/H2O2 can remove up to 67.01% of Br- ions and 56.92% of Cl- ions from water (pH = 7, [Ag-MPs]0 = 100 mg L-1, [H2O2]0 = 0.2 mM); it is reusable, regenerated by radiation and can be easily removed by applying a magnetically assisted chemical separation process.


Assuntos
Iodetos , Prata , Brometos , Cloretos , Peróxido de Hidrogênio
7.
Sci Total Environ ; 650(Pt 1): 1207-1215, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30308808

RESUMO

In this study, a nickel organic xerogel (X-Ni) was used as semiconductor photocatalyst for the degradation of the herbicide diuron (DRN) in aqueous solution. The main objective of this work was to analyze and compare the effectiveness of solar irradiation to remove DRN from water both by direct photolysis and photocatalytic degradation. We examined the influence of the initial concentration of the herbicide, the solution pH, the presence of different ions in the medium, the chemical composition of the water, and the presence of a photocatalyst, after 240 min of irradiation. Direct photolysis achieved a low percentage of DRN degradation but was favored: i) by a reduction in the initial concentration of the herbicide (from 35.6% to 79.0% for 0.150 × 10-3 mol/L and 0.021 × 10-3 mol/L of DRN, respectively) and ii) at solution pHs at which diuron is positively charged (78.6% for pH 2 and 50.4% for pH 7), as suggested by DFT calculations carried out for DRN and its protonated form (DRN-H+). The corresponding mono-demethylated DRN derivative, 1-(3,4-dichlorophenyl)-3-methylurea (DCPU), was identified as a DRN degradation byproduct. In addition, the presence of certain anions in the medium significantly affected the overall degradation process by direct photolysis, due to the additional generation of HO radicals. We highlight that the presence of X-Ni considerably improved the photodegradation process under solar irradiation. The photocatalytic degradation rate constant was directly proportional to the xerogel concentration, because an increase in catalyst dose produced an increase in surface active sites for the photodegradation of DRN, enhancing the overall efficiency of the process. Thus, when 4167 mg/g of X-Ni was added, the DRN removal rate was 3-fold higher and both percentage of degradation and mineralization increased 88.5% with respect to the results obtained by direct photolysis.

8.
J Environ Manage ; 225: 224-231, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30092549

RESUMO

The objective of this study was to analyze the effectiveness of UVC, UVC/H2O2 and UVC/K2S2O8 on the degradation of SAs. Rate constant values increased in the order SMZ < SDZ < SML and showed the higher photodegradation of sulfonamides with a penta-heterocycle. Quantum yields were 1.72 × 10-5 mol E-1, 3.02 × 10-5 mol E-1, and 6.32 × 10-5 mol E-1 for SMZ, SDZ and SML, respectively, at 60 min of treatment. R254 values show that the dose habitually utilized for water disinfection is inadequate to remove this type of antibiotic. The initial sulfonamide concentration has a major impact on the degradation rate. The degradation rates were higher at pH 12 for SMZ and SML. SMZ and SML photodegradation kλ values are higher in tap versus distilled water. The presence of radical promoters generates a greater increase in the degradation rate, UVC/K2S2O8 cost less energy, a mechanism was proposed, and the degradation by-products are less toxic than the original product.


Assuntos
Peróxido de Hidrogênio , Sulfonamidas/química , Poluentes Químicos da Água , Cinética , Oxirredução , Fotólise , Raios Ultravioleta , Purificação da Água
9.
J Environ Manage ; 213: 549-554, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29472036

RESUMO

The objective of this study was to determine the influence of different operational variables on fluoride (F-) removal from waters using lanthanum (La)-doped silica xerogels and the mechanisms involved in this process. Accordingly, four xerogels were synthesized, one acting as blank (X-B), two doped with LaCl3 and dried at different temperatures (X-LaCl and X-LaCl-M), and a fourth doped with La2O3 (X-LaO). The results show that fluorides are only removed when La-doped xerogels are utilized. In addition, X-LaCl yielded the highest adsorption capacity, removing 28.44% of the initial fluoride concentration at a solution pH of 7. Chemical characterization of materials confirmed that fluoride removal from waters is due to the precipitation of LaF3 on the surface of La-doped xerogels. The presence of dissolved organic matter on the aqueous solution also reduce the removal capacity of La xerogels. Finally, analysis of the influence of solution pH revealed that the adsorption capacity of all xerogels was highest at a solution pH of 7.


Assuntos
Fluoretos/isolamento & purificação , Lantânio , Purificação da Água , Adsorção , Fluoretos/química , Concentração de Íons de Hidrogênio , Dióxido de Silício , Poluentes Químicos da Água
10.
Sci Total Environ ; 607-608: 649-657, 2017 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-28709099

RESUMO

The objective of this study was to remove halides from waters by silver nanoparticles (AgNPs) and hydrogen peroxide (H2O2). The experimental parameters were optimized and the mechanism involved was also determined. The AgNP/H2O2 process proved efficacious for bromide and chloride removal from water through the selective precipitation of AgCl and AgBr on the AgNP surface. The optimal AgNP and H2O2 concentrations to be added to the solution were determined for the halide concentrations under study. The removal of Cl- and Br- anions was more effective at basic pH, reaching values of up to 100% for both ions. The formation of OH, O2-, radicals was detected during the oxidation of Ag(0) into Ag(I), determining the reaction mechanism as a function of solution pH. Moreover, the results obtained show that: i) the efficacy of the oxidation of Ag(0) into Ag(I) is higher at pH11, ii) AgNPs can be generated by the O2- radical formation, and iii) the presence of NaCl and dissolved organic matter (tannic acid [TAN]) on the solution matrix reduces the efficacy of bromide removal from the medium due to: i) precipitation of AgCl on the AgNP surface, and ii) the radical scavenger capacity of TAN. AgNPs exhausted can be regenerated by using UV or solar light, and toxicity test results show that AgNPs inhibit luminescence of Vibrio fischeri bacteria.

11.
J Environ Manage ; 169: 116-25, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26731310

RESUMO

This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion.


Assuntos
Café , Diatrizoato/química , Dimetridazol/química , Metronidazol/química , Prunus dulcis/química , Purificação da Água/métodos , Adsorção , Carvão Vegetal/química , Diatrizoato/análise , Difusão , Cinética , Metronidazol/análise
12.
J Colloid Interface Sci ; 401: 116-24, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23623410

RESUMO

The objective of this study was to analyze the equilibrium and adsorption kinetics of nitroimidazoles on activated carbon cloth (ACC), determining the main interactions responsible for the adsorption process and the diffusion mechanism of these compounds on this material. The influence of the different operational variables, such as ionic strength, pH, temperature, and type of water (ultrapure, surface, and waste), was also studied. The results obtained show that the ACC has a high capacity to adsorb nitroimidazoles in aqueous solution. Electrostatic interactions play an important role at pH<3, which favors the repulsive forces between dimetridazole or metronidazole and the ACC surface. The formation of hydrogen bonds and dispersive interactions play the predominant role at higher pH values. Modifications of the ACC with NH3, K2S2O8, and O3 demonstrated that its surface chemistry plays a predominant role in nitroimidazole adsorption on this material. The adsorption capacity of ACC is considerably high in surface waters and reduced in urban wastewater, due to the levels of alkalinity and dissolved organic matter present in the different types of water. Finally, the results of applying kinetic models revealed that the global adsorption rate of dimetridazole and metronidazole is controlled by intraparticle diffusion.


Assuntos
Carbono/química , Nitroimidazóis/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Soluções , Propriedades de Superfície , Temperatura , Água/química
13.
J Hazard Mater ; 217-218: 76-84, 2012 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-22472426

RESUMO

The objective of this study was to optimize the preparation of treatment plant wastewater sludge adsorbents for application in water treatment. The optimal adsorption capacity was obtained with adsorbents prepared by pyrolysis at 700°C for 3h. We studied the effect of binder type on the adsorbents, finding that their textural properties were not substantially affected by the addition of phenolic resins but their surface area was reduced by the presence of clayey soil. Analysis of the composition of surface groups in these materials revealed: (i) a high concentration of basic surface groups in non-activated pyrolyzed sludge, (ii) an increase in the concentration of basic surface groups after chemical activation, (iii) no modification in the concentration of carboxyl or basic groups with the addition of binding agent before the activation, and (iv) total disappearance of carbonyl groups from sample surfaces with the addition of humic acid or clayey soil as binder. All these adsorbents had a low C content. The capacity of these sludge-derived materials to adsorb methylene blue, 2,4-dichlorophenol, tetracycline, and (Cd(II)) was studied. Their adsorption capacity was considerably increased by the chemical activation but reduced by the pre-activation addition of a binding agent (humic acid, phenolic resin, and clayey soil).


Assuntos
Esgotos , Poluentes da Água/química , Adsorção
14.
An. vet. Murcia ; 27: 119-128, ene.-dic. 2011. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-106595

RESUMO

La enfermedad cardiovascular es hoy en día la primera causa de mortalidad en las sociedades desarrolladas. Dada la complejidad del desarrollo de la lesión aterosclerótica en el ser humano resulta interesante investigar en modelos animales en los que dicho proceso sea semejante a la enfermedad humana. El pollo, al igual que otras aves, es capaz de desarrollar arteriosclerosis aórtica y coronaria de forma natural o espontánea, e inducida por una dieta enriquecida en colesterol. Teniendo en cuenta que la mayoría de los trabajos publicados describen las lesiones en segmentos aórticos y la variedad de métodos de inducción de la arteriosclerosis, el objetivo de esta investigación es caracterizar de manera adecuada en el modelo aviar utilizado, las lesiones arterioscleróticas de troncos supra-aórticos en un grupo experimental con respecto a un grupo control. Se emplearon 20 pollos de la raza White Leghorn divididos en dos grupos (control y aterogénico) que recibían una dieta normal o hiperlipémica respectivamente durante un periodo de 6 meses. Se sacrificaron entonces los animales para llevar a cabo el estudio bioquímico del plasma (perfil lipídico), evaluación histológica de los troncos supra-aórticos y valoración semicuantitativa de las lesiones según la clasificación de Stary. Se observaron diferencias estadísticamente significativas entre ambos grupos para los diferentes parámetros bioquímicos estudiados y para la cuantificación del grado de lesión de Stary. En el grupo aterogénico se observó un endotelio conservado, con íntimas muy aumentadas de tamaño (10 veces el tamaño del grupo control) y muy desorganizadas. En conclusión, estos hallazgos confirman el uso del pollo como biomodelo experimental para el estudio de la arteriosclerosis en troncos supra-aórticos, y podrían ser empleados como referencia para futuros estudios intervencionistas(AU)


Cardiovascular diseases are considered first cause of human mortality in developed countries. Animal models allow adequate research of atherosclerosis, given the similarities with the human lesions. Chickens may develop spontaneous and also induced atherosclerosis by use of a cholesterol-enriched diet. Most published findings describe aortic lesions in a variety of induction methods. Therefore, the aim of this research is to characterize the used avian model, describing supra-aortic trunk lesions in atherosclerotic chickens and to compare it with control animals. Twenty White Leghorn chickens were used (10 controls fed with a normal diet and 10 atherogenic animals fed with a hyperlipidemic diet, for 6 months). After sacrifice, lipid biochemical parameters were analysed, as well as histologic evaluation of supra-aortic vessels and quantification of lesions following the Stary classification. Statistically significant differences for each parameter were observed between the control and experimental groups. Increased intima layer width with disorganization was observed in atherogenic animals. These findings confirm the use of the chicken as an adequate experimental animal for atherosclerosis, and could be used as a reference for future interventional studies(AU)


Assuntos
Animais , Embrião de Galinha , Galinhas , Modelos Animais , Arteriosclerose/complicações , Arteriosclerose/diagnóstico , Arteriosclerose/terapia , Arteriosclerose/veterinária , Experimentação Animal
15.
J Hazard Mater ; 187(1-3): 1-23, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21306824

RESUMO

The main objective of this study was to list and compare the advantages and disadvantages of different methodologies to modify the surface of activated carbons (ACs) for their application as adsorbents to remove organic and inorganic pollutants from aqueous phase. These methodologies have been categorized into four broad groups: oxidation, sulfuration, ammonification, and coordinated ligand anchorage. Numerous investigations into the removal of metals from water have modified carbon surfaces to increase their content of acidic surface functional groups by using H(2)O(2), O(3) and HNO(3). Because these treatments can reduce the AC surface area, researchers are seeking alternative methods to modify and/or create surface functional groups without the undesirable effect of pore blockage. The nitrogenation or sulfuration of the AC surface can increase its basicity favoring the adsorption of organic compounds. The introduction of nitrogen or sulfur complexes on the carbon surface increases the surface polarity and, therefore, the specific interaction with polar pollutants. Different coordinated ligands have also been used to modify ACs, showing that coordinated ligand anchorage on the AC surface modifies its textural and chemical properties, but research to date has largely focused on the use of these modified materials to remove heavy metals from water by complexes formation.


Assuntos
Carbono/química , Poluentes da Água/isolamento & purificação , Abastecimento de Água
16.
Water Res ; 45(1): 393-403, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20850862

RESUMO

The objective of this study was to analyze the efficacy of ultraviolet (UV) radiation in the direct photodegradation of nitroimidazoles. For this purpose, i) a kinetic study was performed, determining the quantum yield of the process; and ii) the influence of the different operational variables was analyzed (initial concentration of antibiotic, pH, presence of natural organic matter compounds, and chemical composition of water), and the time course of total organic carbon (TOC) concentration and toxicity during nitroimidazole photodegradation was studied. The very low quantum yields obtained for the four nitroimidazoles are responsible for the low efficacy of the quantum process during direct photon absorption in nitroimidazole phototransformation. The R(254) values obtained show that the dose habitually used for water disinfection is not sufficient to remove this type of pharmaceutical; therefore, higher doses of UV irradiation or longer exposure times are required for their removal. The time course of TOC and toxicity during direct photodegradation (in both ultrapure and real water) shows that oxidation by-products are not oxidized to CO(2) to the desired extent, generating oxidation by-products that are more toxic than the initial product. The concentration of nitroimidazoles has a major effect on their photodegradation rate. The study of the influence of pH on the values of parameters ɛ (molar absorption coefficient) and k'(E) (photodegradation rate constant) showed no general trend in the behavior of nitroimidazoles as a function of the solution pH. The components of natural organic matter, gallic acid (GAL), tannic acid (TAN) and humic acid (HUM), may act as promoters and/or inhibitors of OH· radicals via photoproduction of H(2)O(2). The effect of GAL on the metronidazole (MNZ) degradation rate markedly differed from that of TAN or HUM, with a higher rate at low GAL concentrations. Differences in MNZ degradation rate among waters with different chemical composition are not very marked, although the rate is slightly lower in wastewaters, mainly due to the UV radiation filter effect of this type of water.


Assuntos
Antibacterianos/química , Antibacterianos/efeitos da radiação , Nitroimidazóis/química , Nitroimidazóis/efeitos da radiação , Fotólise , Raios Ultravioleta , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos
17.
Ars pharm ; 51(supl.2): 407-411, mayo 2010. tab
Artigo em Espanhol | IBECS | ID: ibc-88661

RESUMO

El perfil propio de cada centro tanto desde el punto de vista académico, como profesional, vienemarcado por la claridad de las competencias genéricas y especificas que han de alcanzar sus titulados.La dificultad de la gestión transversal del mapa de competencias de una titulación reside, entre otras,en la necesidad de que cada competencia se ha de servir desde una o más asignaturas y cada asignaturaha de servir a una o más competencias. El objetivo del presente trabajo consiste en sintetizar elproceso de definición e implementación de las competencias de la titulación del Grado en Farmacia,teniendo en cuenta que éstas se han de adecuar, permanentemente, a las demandas sociales, a losrequisitos de calidad de la formación universitaria y a la mejora continua de sus procesos en el marcodel Espacio Europeo de Educación Superior (EEES) y de la legislación vigente. Se especifican lascapacidades, habilidades, valores y actitudes personales, a nivel de organización y técnicas a corto,medio y largo plazo, que facultan a los titulados para llevar a cabo las funciones propias de susestudios y que los capacita para el pleno desarrollo de su ejercicio profesional(AU)


Assuntos
Humanos , Masculino , Feminino , Educação Baseada em Competências/organização & administração , Educação em Farmácia/métodos , Educação em Farmácia/ética , Educação Baseada em Competências/métodos , Educação Baseada em Competências/normas , Educação Baseada em Competências/tendências , Educação em Farmácia/organização & administração , Educação em Farmácia/tendências
18.
J Colloid Interface Sci ; 345(2): 481-90, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20193953

RESUMO

The adsorption kinetics of four nitroimidazoles, Dimetridazole (DMZ), Metronidazole (MNZ), Ronidazole (RNZ) and Tinidazole (TNZ), were studied on three activated carbons: two commercial carbons from Sorbo-Norit (S) and Merck (M) and a third prepared by chemical activation of petroleum coke (C). Experimental data of the corresponding adsorption kinetics were analyzed by applying pseudo-first and pseudo-second-order models and a general diffusion model. Application of pseudo-first and pseudo-second-order kinetic models verified the following: (i) The kinetic model used that better predicts the adsorption rates depends of both the adsorbent and adsorbate studied. (ii) Nitroimidazole adsorption rate decreases in the order MNZ>DMZ>RNZ>TNZ; therefore, in the case of MNZ, molecular size does not appear to be a determining factor in the process. (iii) Nitroimidazole adsorption rate on carbons increases in the order C

Assuntos
Antibacterianos/química , Carvão Vegetal/química , Modelos Químicos , Nitroimidazóis/química , Adsorção , Interações Hidrofóbicas e Hidrofílicas , Cinética
19.
J Hazard Mater ; 174(1-3): 880-6, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19815338

RESUMO

The main objective of the present study was to analyze the efficacy of technologies based on ozone and activated carbon in dynamic regime to remove organic micropollutants from waters, using the antibiotic tinidazole (TNZ) as a model compound. Results obtained in static regime show that the presence of activated carbon (GAC) during tinidazole ozonation: (i) increases its removal rate, (ii) reduces oxidation by-product toxicity, and (iii) reduces the concentration of dissolved organic matter. Study of the ozone/activated carbon system in dynamic regime showed that ozonation of tinidazole before the adsorption process considerably improves column performance, increasing the volume of water treated. It was observed that the efficacy of the treatment considerably increased with a shorter contact time between TNZ and O(3) streams before entering the column allowing a much higher volume of TNZ solution to be treated compared with the use of activated carbon alone, and reducing by 75% the amount of activated carbon required per unit of treated water volume. TNZ removal by the O(3)/GAC system is lower in natural waters and especially in wastewaters, than in ultrapure water. The toxicity results obtained during TNZ treatment with O(3)/GAC system showed that toxicity was directly proportional to the concentration of TNZ in the effluent, verifying that oxidation of the organic matter in the natural waters did not increase the toxicity of the system.


Assuntos
Carbono/química , Ozônio/química , Tinidazol/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Cromatografia Líquida de Alta Pressão
20.
Water Res ; 43(16): 4028-36, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19541339

RESUMO

The main objectives of this study were: (1) to investigate the decomposition and mineralization of nitroimidazoles (Metronidazole [MNZ], Dimetridazole [DMZ], and Tinidazole [TNZ]) in waste and drinking water using gamma irradiation; (2) to study the decomposition kinetics of these nitroimidazoles; and (3) to evaluate the efficacy of nitroimidazole removal using radical promoters and scavengers. The results obtained showed that nitroimidazole concentrations decreased with increasing absorbed dose. No differences in irradiation kinetic constant were detected for any nitroimidazole studied (0.0014-0.0017 Gy(-1)). The decomposition yield was higher under acidic conditions than in neutral and alkaline media. Results obtained showed that, at appropriate concentrations, H(2)O(2) accelerates MNZ degradation by generating additional HO(); however, when the dosage of H(2)O(2) exceeds the optimal concentration, the efficacy of MNZ degradation is reduced. The presence of t-BuOH (HO() radical scavenger) and thiourea (HO(), H() and e(aq)(-) scavenger) reduced the MNZ irradiation rate, indicating that degradation of this pollutant can take place via two pathways: oxidation by HO() radicals and reduction by e(aq)(-) and H(). MNZ removal rate was slightly lower in subterranean and surface waters than in ultrapure water and was markedly lower in wastewater. Regardless of the water chemical composition, MNZ gamma irradiation can achieve i) a decrease in the concentration of dissolved organic carbon, and ii) a reduction in the toxicity of the system with higher gamma absorbed dose.


Assuntos
Anti-Infecciosos/efeitos da radiação , Raios gama , Nitroimidazóis/efeitos da radiação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/efeitos da radiação , Anti-Infecciosos/análise , Dimetridazol/análise , Dimetridazol/efeitos da radiação , Peróxido de Hidrogênio/análise , Concentração de Íons de Hidrogênio , Cinética , Metronidazol/análise , Metronidazol/efeitos da radiação , Nitroimidazóis/análise , Tioureia/análise , Tinidazol/análise , Tinidazol/efeitos da radiação , Água/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , terc-Butil Álcool/análise
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