Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 346
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Environ Res ; 247: 118281, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38266891

RESUMEN

This study reports on the application of activated carbons from macadamia nut shells as adsorbents for the removal of 2,4-dichlorophenoxyacetic acid, a commonly used pesticide, from water. Different activating agents (FeCl3, ZnCl2, KOH and H3PO4) were used to obtain adsorbents within a wide range of porous texture and surface properties. The characterization of the resulting activated carbons was performed by N2 adsorption-desorption, elemental analysis, TG and pHPZC. The adsorption experiments were conducted in batch at 25, 45 and 65 °C. The adsorption kinetics on activated carbons obtained with FeCl3 H3PO4 or KOH was well described by the pseudo-second order model, whereas for the resulting from ZnCl2 activation the experimental data fit better the pseudo-first order model. The equilibrium studies were performed with the KOH- and ZnCl2-activated carbons, the two showing higher surface area values. In both cases, high adsorption capacities were obtained (c.a. 600 mg g-1) and the experimental data were better described by the Langmuir and Toth models. The thermodynamic study allows concluding the spontaneous and endothermic character of the adsorption process, as well as an increase of randomness at the solid/liquid interface. Breakthrough curves were also obtained and fitted to the logistic model.


Asunto(s)
Cloruros , Compuestos Férricos , Herbicidas , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Macadamia , Fenoxiacetatos , Ácido 2,4-Diclorofenoxiacético , Cinética , Contaminantes Químicos del Agua/análisis
2.
J Investig Allergol Clin Immunol ; 33(2): 119-125, 2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-34896979

RESUMEN

BACKGROUND AND OBJECTIVE: Previous studies suggest that asthma mortality rates in Spain have been decreasing in recent years. However, this trend is not homogeneous across age groups. Objective: To analyze asthma mortality rates over a 40-year period, focusing on changes associated with the development of new therapeutic approaches. METHODS: Death records and mid-year population data were collected from the National Statistics Institute. Using the direct method, agestandardized mortality rates were calculated for the overall population and for each sex and age group. Significant changes in mortality trends were identified using joinpoint regression analysis. The independent effects of age, period, and cohort and potential years of life lost due to asthma were also analyzed. RESULTS: Age-standardized asthma mortality rates decreased in Spain from 7.38 to 2.03 deaths per 100 000 from the first to the last quinquennium of the study (1980-1984 to 2015-2019) for the whole population. This decrease was more intense among men, where a decrease from 10.37/100 000 to 0.91/100 000 was observed compared with 5.53 to 2.77/100 000 in women. Mortality decreased in all age groups. During the last 3 years, the decrease stabilized in patients aged >64 years but increased in those aged 35-64. Mortality has been decreasing rapidly since the 1990s in patients aged <35 years. CONCLUSION: Asthma mortality rates began to decline in 1980. The decrease was observed among younger cohorts starting in the 1990s, thus confirming earlier trends. Improved diagnosis and development of new therapies for asthma may have played a role in the changes observed. Close monitoring of asthma mortality rates is necessary to confirm these trends.


Asunto(s)
Asma , Masculino , Humanos , Femenino , España/epidemiología , Análisis de Regresión
3.
J Environ Manage ; 320: 115769, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-35944316

RESUMEN

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.


Asunto(s)
Ozono , Contaminantes Químicos del Agua , Purificación del Agua , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Antibacterianos , Medios de Contraste , Hospitales , Humanos , Eliminación de Residuos Líquidos/métodos , Aguas Residuales , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
4.
Biotechnol Bioeng ; 118(3): 1152-1165, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33236769

RESUMEN

Biofouling represents an important limitation in photobioreactor cultures. The biofouling propensity of different materials (polystyrene, borosilicate glass, polymethyl methacrylate, and polyethylene terephthalate glycol-modified) and coatings (two spray-applied and nanoparticle-based superhydrophobic coatings and a hydrogel-based fouling release coating) was evaluated by means of a short-term protein test, using bovine serum albumin (BSA) as a model protein, and by the long-term culture of the marine microalga Nannochloropsis gaditana under practical conditions. The results from both methods were similar, confirming that the BSA test predicts microalgal biofouling on surfaces exposed to microalgae cultures whose cells secrete macromolecules, such as proteins, with a high capacity for forming a conditioning film before cell adhesion. The hydrogel-based coating showed significantly reduced BSA and N. gaditana adhesion, whereas the other surfaces failed to control biofouling. Microalgal biofouling was associated with an increased concentration of sticky extracellular proteins at low N/P ratios (below 15).


Asunto(s)
Proteínas Algáceas , Incrustaciones Biológicas , Materiales Biocompatibles Revestidos/química , Hidrogeles/química , Microalgas/crecimiento & desarrollo , Estramenopilos/crecimiento & desarrollo , Proteínas Algáceas/química , Proteínas Algáceas/metabolismo , Albúmina Sérica Bovina/química , Propiedades de Superficie
5.
Biofouling ; 37(8): 844-861, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34538160

RESUMEN

Adhesion of microalgal cells to photobioreactor walls reduces productivity resulting in significant economic losses. The physico-chemical surface properties and the fluid dynamics present in the photobioreactor during cultivation are relevant. However, to date, no multiphysical model has been able to predict biofouling formation in these systems. In this work, to model the microalgal adhesion, a Computational Fluid Dynamic simulation was performed using a Eulerian-Lagrangian particle-tracking model. The adhesion criterion was based on the balance of forces and moments included in the XDLVO model. A cell suspension of the marine microalga Nannochloropsis gaditana was fed into a commercial flow cell composed of poly-methyl-methacrylate coupons for validation. Overall, the simulated adhesion criterion qualitatively predicted the initial distribution of adhered cells on the coupons. In conclusion, the combined Computational Fluid Dynamics-Discrete Phase Model (CFD-DPM) approach can be used to overcome the challenge of predicting microalgal cell adhesion in photobioreactors.


Asunto(s)
Incrustaciones Biológicas , Microalgas , Hidrodinámica , Fotobiorreactores , Propiedades de Superficie
6.
J Eur Acad Dermatol Venereol ; 35(4): 884-891, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33030772

RESUMEN

BACKGROUND: Recent studies suggest that cutaneous melanoma mortality rates in Spain are stabilizing and even decreasing in younger cohorts. OBJECTIVES: To analyse mortality rates of melanoma from the last 40 years, focusing on changes related with the development of new therapeutic approaches. METHODS: Death records and mid-year population data were collected from the National Statistics Institute. By using the direct method, age-standardized mortality rates were calculated for overall population and for each sex and age group. Significant changes in mortality trends were identified by Joinpoint regressions. The independent effects of age, period and cohort (APC) and potential years of life lost (PYLL) due to melanoma were also analysed. RESULTS: Age-standardized melanoma mortality rates rose in Spain from 0.78 to 2.13 deaths per 100 000 from the first to the last quinquennium of the study (1979-1983 to 2014-2018) for the overall population. After a marked increase until 1995, mortality rates levelled off. Following this stabilization, from 2015 to 2018 there was a decrease in mortality rates for the overall population (average annual per cent change (AAPC): -4.3, not significant), more accused in males over 64 years old (yo). A period effect was observed from the beginning of 21st century, with mortality rates dropping to date. CONCLUSIONS: There is a decrease in melanoma mortality rates from 2015 in all age groups that confirms previous trends in mortality in younger cohorts. Improvement in diagnosis and development of new therapies for advanced melanoma may have a crucial role in this event. Close monitoring of melanoma mortality rates is necessary to confirm these trends.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Estudios de Cohortes , Humanos , Inmunoterapia , Masculino , Melanoma/terapia , Persona de Mediana Edad , Neoplasias Cutáneas/terapia , España/epidemiología
7.
Mol Phylogenet Evol ; 150: 106859, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32497831

RESUMEN

Parapanteles Ashmead (Braconidae: Microgastrinae) is a medium-sized genus of microgastrine wasps that was erected over a century ago and lacks a unique synapomorphic character, and its monophyly has not been tested by any means. Parapanteles usually are parasitoids of large, unconcealed caterpillars (macrolepidoptera) and have been reared from an unusually large diversity of hosts for a relatively small microgastrine genus. We used Cytochrome Oxidase I sequences ("DNA barcodes") available for Parapanteles and other microgastrines to sample the generic diversity of described and undescribed species currently placed in Parapanteles, and then sequenced four additional genes for this subsample (wingless, elongation factor 1-alpha, ribosomal subunit 28s, and NADH dehydrogenase subunit 1). We constructed individual gene trees and concatenated Bayesian and maximum-likelihood phylogenies for this 5-gene subsample. In these phylogenies, most Parapanteles species formed a monophyletic clade within another genus, Dolichogenidea, while the remaining Parapanteles species were recovered polyphyletically within several other genera. The latter likely represent misidentified members of other morphologically similar genera. Species in the monophyletic clade containing most Parapanteles parasitized caterpillars from only five families - Erebidae (Arctiinae), Geometridae, Saturniidae, Notodontidae, and Crambidae. We do not make any formal taxonomic decisions here because we were not able to include representatives of type species for Parapanteles or other relevant genera, and because we feel such decisions should be reserved until a comprehensive morphological analysis of the boundaries of these genera is accomplished.


Asunto(s)
Himenópteros/clasificación , Animales , Teorema de Bayes , Complejo IV de Transporte de Electrones/clasificación , Complejo IV de Transporte de Electrones/genética , Himenópteros/genética , Proteínas de Insectos/clasificación , Proteínas de Insectos/genética , NADH Deshidrogenasa/clasificación , NADH Deshidrogenasa/genética , Filogenia , ARN Ribosómico 28S/clasificación , ARN Ribosómico 28S/genética
8.
Ecotoxicol Environ Saf ; 187: 109836, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31675504

RESUMEN

Toxicity of 13 ionic liquids (ILs) corresponding to different families were studied by inhibition respiration assays (15 min) using activated sludge. Toxicity increased as increasing the number of carbons in the alkyl-chain of imidazolium-based ILs, with EC50 values from 4.19 to 0.17 for 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]) and 1-octyl-3-methylimidazolium chloride ([Omim][Cl]), respectively. An increase in toxicity was observed for aromatic-based ILs (pyridinium- and imidazolium-based ILs) due to the hydrophobic character of the head groups in comparison with linear structures as phosphonium and ammonium cations. Among to the anions studied fixing [Emim]+ as cation, [HSO4]- and [NTf2]- presented low EC50 values (0.34 mM and 1.69 mM, respectively) while [Cl]- and [EtSO4]- were considered harmless anions due to the hydrophilic character of chloride and the organic nature of [EtSO4]-. ILs toxicity/inhibition was determined by adding a biodegradable compound and measuring the sludge response after being in contact with the ILs for at least 15 h. The exposure of sewage sludge to ILs for more than 15 min used in short inhibition assays caused more toxic effect on microorganisms, even for [Choline][NTf2], previously defined as practically harmless (EC50 = 2.79 mM). Biodegradability assays confirmed the biodegradable nature of choline cation, related with TOC conversion of 40%, only due to cation consumption. No oxygen consumption or even lysis of microbial cells was observed for Tetrabutylammonium bis(trifluoromethylsulfonyl)imide and for 1-Ethyl-3-methylimidazolium hydrogensulphate due to the presence of anions previously defined as hazardous ([NTf2]- and [HSO4]-), maintaining their recalcitrant character to sewage systems.


Asunto(s)
Imidazoles/toxicidad , Líquidos Iónicos/toxicidad , Aguas del Alcantarillado/microbiología , Aniones , Biodegradación Ambiental , Cationes , Interacciones Hidrofóbicas e Hidrofílicas , Imidazoles/química , Líquidos Iónicos/química , Estructura Molecular
9.
J Environ Manage ; 274: 111199, 2020 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-32805473

RESUMEN

Aqueous phase reforming (APR) coupled to catalytic wet air oxidation (CWAO) has been investigated as an approach to remove phenolic compounds from wastewater, converting them into valuable gases. Partial oxidation of phenol was achieved in the first CWAO stage trying to minimize mineralization so to allow a high yield to valuable gases in the second APR stage. APR runs were carried out with different mixtures of compounds corresponding to phenol oxidation pathway (phenol, quinones, long and short chain acids) and representing different degrees of oxidation in CWAO stage. A range of TOC and COD removal (74-90%) was observed in APR stage for the single compounds, with higher removal for long chain acids. Likewise, long chain acids provided with the highest conversion to gases. APR of mixtures rich in acids gave the highest yield to CH4 (11.0 mmol CH4/g TOCinitial). H2 production was low in all cases, due to competing direct conversion of long and short chain acids into CH4. TOC and COD removal from wastewater was similar in APR-CWAO and APR, however the conversion to gases and the yield to CH4 were markedly higher for APR-CWAO, thus overcoming the difficulties previously observed in the direct APR of phenol.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Catálisis , Oxidación-Reducción , Fenoles , Eliminación de Residuos Líquidos
10.
Molecules ; 25(7)2020 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-32252408

RESUMEN

To encourage the reutilization of treated wastewaters as an adaptation strategy to climate change it is necessary to demonstrate their quality. If this is ensured, reclaimed waters could be a valuable resource that produces very little environmental impact and risks to human health. However, wastewaters are one of the main sources of emerging pollutants that are discharged in the environment. For this, it is essential to assess the presence of these pollutants, especially pharmaceutical compounds, in treated wastewaters. Moreover, the different treatment processes must be evaluated in order to know if conventional and natural treatment technologies are efficient in the removal of these types of compounds. This is an important consideration if the treated wastewaters are used in agricultural activities. Owing to the complexity of wastewater matrixes and the low concentrations of pharmaceutical residues in these types of samples, it is necessary to use sensitive analytical methodologies. In this study, the presence of 11 pharmaceutical compounds were assessed in three different wastewater treatment plants (WWTPs) in Gran Canaria (Spain). Two of these WWTPs use conventional purification technologies and they are located in densely populated areas, while the other studied WWTP is based in constructed wetlands which purify the wastewaters of a rural area. The sampling was performed monthly for two years. A solid phase extraction (SPE) coupled to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was applied for the analysis of the samples, and the 11 pharmaceuticals were detected in all the studied WWTPs. The concentrations were variable and ranged from ng·L-1 in some compounds like diclofenac or carbamazepine to µg·L-1 in common pharmaceutical compounds such as caffeine, naproxen or ibuprofen. In addition, removal efficiencies in both conventional and natural purification systems were evaluated. Similar removal efficiencies were obtained using different purifying treatments, especially for some pharmaceutical families as stimulants or anti-inflammatories. Other compounds like carbamazepine showed a recalcitrant behavior. Secondary treatments presented similar removal efficiencies in both conventional and natural wastewater treatment plants, but conventional treatments showed slightly higher elimination ratios. Regarding tertiary system, the treatment with highest removal efficiencies was reverse osmosis in comparison with microfiltration and electrodialysis reversal.


Asunto(s)
Preparaciones Farmacéuticas/análisis , Aguas Residuales/química , Purificación del Agua/métodos , Cromatografía Líquida de Alta Presión , Cambio Climático , Monitoreo del Ambiente , Extracción en Fase Sólida , España , Espectrometría de Masas en Tándem , Calidad del Agua
14.
Ecotoxicol Environ Saf ; 162: 29-34, 2018 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-29960119

RESUMEN

The ecotoxicity and inhibition of 12 imidazolium ionic liquids (ILs) with alkyl chain from C4 to C10 and chloride (Cl-), tetrafluoroborate (BF4-) and bis(trifluoromethanesulfonyl)imide (NTf2-) anions have been studied by means of respiration inhibition assays using activated sludge collected from a wastewater treatment plant. This test represents an alternative easy, economic and quick way to evaluate the true impact of ILs on activated sludge-based wastewater treatment. For comparison purposes, the EC50 values were also determined by the Microtox test (Vibrio fischeri). It was observed that this widely used microbial test overestimates the effect of the ILs on biological wastewater treatment facilities, especially in the case of ILs with lower ecotoxicity. The results of the biological tests showed that the alkyl chain length plays a crucial role in the ecotoxicity of ILs. A significant increase of the toxicity with the length of the n-alkyl chain was found. Regarding to the impact of the anion, the ecotoxicity measured by respiration inhibition assays follows the order NTf2- > Cl- > BF4-, being the anion effect higher as decreasing the length of cation alkyl chain. According to the hazard substances ranking for aquatic organisms (Passino and Smith, 1987), imidazolium ILs with C4 alkyl chain can be classified as "practically harmless" compounds whereas those with alkyl chains C8 or C10 correspond to "highly toxic" species.


Asunto(s)
Imidazoles/toxicidad , Líquidos Iónicos/toxicidad , Aliivibrio fischeri/efectos de los fármacos , Aniones , Cationes , Imidazoles/química , Líquidos Iónicos/química , Oxígeno/análisis , Aguas del Alcantarillado , Aguas Residuales
18.
J Helminthol ; 89(5): 593-600, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25007240

RESUMEN

The aim of this study was to assess the effect of infection with the nematode whipworm Trichuris muris on the course of chemically induced acute ulcerative colitis in CBA/J mice, a strain proven to be highly resistant to infection with T. muris. Each mouse was infected with 50 embryonated eggs of T. muris by oral gavage. Acute colitis was triggered by administering 4% dextran sulphate sodium (DSS) in the drinking water for nine consecutive days at different times after infection. Concurrent infection and DSS administration exacerbate the severity of the colitis while favouring the permanence of parasites in the intestine. The induction of ulcerative colitis from days 54 to 62 post-infection (p.i.), when all worms had been expelled, ameliorated the course of the inflammatory disease. When ulcerative colitis was triggered earlier on, from days 27 to 35 p.i., the beneficial effects on inflammatory events were clearly shown with signs of mucosal epithelization and regeneration as early as day 1 after DSS administration. Previous infections by T. muris therefore accelerate recovery from subsequently induced inflammatory bowel disease and such an effect assists the nematode to persist in the intestinal niche.


Asunto(s)
Colitis Ulcerosa/patología , Tricuriasis/patología , Trichuris/fisiología , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/parasitología , Modelos Animales de Enfermedad , Femenino , Humanos , Intestinos/parasitología , Ratones , Ratones Endogámicos CBA , Tricuriasis/parasitología
19.
Neurologia ; 30(8): 488-95, 2015 Oct.
Artículo en Inglés, Español | MEDLINE | ID: mdl-24950858

RESUMEN

INTRODUCTION: Cerebrovascular disease is the third-leading cause of death and the second-leading cause of disability and dementia. OBJECTIVE: Determine stroke incidence and risk factors in a population of adults aged 65 and over in Cuba (Havana and Matanzas). MATERIAL AND METHODS: This prospective longitudinal study, completed between April 2008 and Abril 2011, re-evaluated 2916 elderly adults with an average follow-up time of 4 years. Cases included 2316 living subjects and 600 verbal autopsies. Study variables were age, sex, educational level, self-reported health, and description of chronic diseases and substance abuse. Laboratory tests included genotyping APOE. Stroke was diagnosed based on the World Health Organization definition. We calculated the global incidence rate for stroke, broken down by sex, age group, and risk factors for incident stroke. RESULTS: Stroke incidence was 786.2 in 100000 persons/year (95% CI: 672.3-906.4). History of alcohol consumption (HR: 3.5; 95% CI: 3.3-3.7), dementia (HR: 3.0; 95% CI, 1.6-5.5) and male sex (HR: 1.8; 95% CI, 1.2-2.8) were shown to be risk factors for incident stroke. CONCLUSIONS: Stroke incidence was similar to rates reported in developed countries and lower than that in low- to middle-income countries. Given that diabetes mellitus, heart disease, arterial hypertension, smoking, APOE4, etc. are associated with higher mortality rates, they will require separate analysis in a study of stroke risk factors.


Asunto(s)
Accidente Cerebrovascular/epidemiología , Anciano , Anciano de 80 o más Años , Cuba/epidemiología , Femenino , Humanos , Incidencia , Entrevistas como Asunto , Masculino , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Factores Sexuales
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA