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1.
Appl Radiat Isot ; 204: 111109, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38029636

RESUMEN

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides. The exercise input files and calculation results with practical recommendations are made available for new users on a dedicated webpage.

2.
Appl Radiat Isot ; 155: 108921, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31629294

RESUMEN

An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.

3.
Appl Radiat Isot ; 154: 108850, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31476556

RESUMEN

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

4.
Photodiagnosis Photodyn Ther ; 26: 203-209, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30910734

RESUMEN

BACKGROUND: We compared the effectiveness of a single irradiation vs repetitive irradiation of light, for in vitro photodynamic inactivation (PDI) of Candida albicans and Trichophyton mentagrophytes, by using methylene blue (MB) and rose bengal (RB) as photosensitizers (PS). METHODS: MB from 5 to 60 µM and RB from 0.5 to 10 µM, with energy densities from 10 to 60 J/cm2, were tested in C. albicans. We further optimize the PDI by reducing the light energy density and PS concentration for the single irradiation experiments by using repetitive doses (two and three times). MB was tested in C. albicans and T. mentagrophytes, and RB was tested in C. albicans. RESULTS: MB-PDI and RB-PDI in C. albicans significantly reduced the number of colony-forming units per milliliter (CFU/mL) when compared to the control groups. Using a single irradiation, over 99% growth inhibition of C. albicans was obtained with MB at 20 µM-60 J/cm2, and with RB at 1 µM-30 J/cm2 and 5 µM-10 J/cm2. With repetitive doses, similar results were obtained by reducing several times the light energy density and the PS concentration for C. albicans and T. mentagrophytes. CONCLUSIONS: The results showed that RB was more effective than MB for C. albicans inactivation. In addition, it is possible to significantly reduce the amount of PS and light energy density requirements by using repetitive irradiations in both genera tested. It makes the technique less invasive and could reduce the side effects in people extremely sensitive to the PS or the light.


Asunto(s)
Candida albicans/efectos de los fármacos , Azul de Metileno/farmacología , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Rosa Bengala/farmacología , Trichophyton/efectos de los fármacos , Técnicas In Vitro
5.
Opt Express ; 26(6): 6653-6662, 2018 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-29609352

RESUMEN

The generation and manipulation of microbubbles by means of temperature gradients induced by low power laser radiation is presented. A laser beam (λ = 1064 nm) is divided into two equal parts and coupled to two multimode optical fibers. The opposite ends of each fiber are aligned and separated a distance D within an ethanol solution. Previously, silver nanoparticles were photo deposited on the optical fibers ends. Light absorption at the nanoparticles produces a thermal gradient capable of generating a microbubble at the optical fibers end in non-absorbent liquids. The theoretical and experimental studies carried out showed that by switching the thermal gradients, it is possible to generate forces in opposite directions, causing the migration of microbubbles from one fiber optic tip to another. Marangoni force induced by surface tension gradients in the bubble wall is the driving force behind the manipulation of microbubbles. We estimated a maximum Marangoni force of 400nN for a microbubble with a radius of 110 µm.

6.
Appl Radiat Isot ; 109: 482-486, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26651169

RESUMEN

The aim of this study was to check for equivalence of computer codes that are capable of performing calculations of true coincidence summing (TCS) correction factors. All calculations were performed for a set of well-defined detector parameters, sample parameters and decay scheme data. The studied geometry was a point source of (133)Ba positioned directly on the detector window of a low-energy (n-type) detector. Good agreement was established between the TCS correction factors computed by the different codes.

7.
J Environ Manage ; 168: 36-45, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26696604

RESUMEN

Globally, efforts are underway to reduce anthropogenic greenhouse gas emissions and to adapt to climate change impacts at the local level. However, there is a poor understanding of the relationship between city strategies on climate change mitigation and adaptation and the relevant policies at national and European level. This paper describes a comparative study and evaluation of cross-national policy. It reports the findings of studying the climate change strategies or plans from 200 European cities from Austria, Belgium, Estonia, Finland, France, Germany, Ireland, Italy, Netherlands, Spain and the United Kingdom. The study highlights the shared responsibility of global, European, national, regional and city policies. An interpretation and illustration of the influences from international and national networks and policy makers in stimulating the development of local strategies and actions is proposed. It was found that there is no archetypical way of planning for climate change, and multiple interests and motivations are inevitable. Our research warrants the need for a multi-scale approach to climate policy in the future, mainly ensuring sufficient capacity and resource to enable local authorities to plan and respond to their specific climate change agenda for maximising the management potentials for translating environmental challenges into opportunities.


Asunto(s)
Ciudades , Cambio Climático , Formulación de Políticas , Europa (Continente) , Humanos , Urbanización
8.
Biomed Opt Express ; 6(10): 4079-87, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26504655

RESUMEN

In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters.

9.
Rehabilitación (Madr., Ed. impr.) ; 48(4): 226-231, oct.-dic. 2014.
Artículo en Español | IBECS | ID: ibc-129589

RESUMEN

Introducción. El objetivo de este estudio es valorar las características del dolor, la capacidad funcional y el tratamiento farmacológico de pacientes con gonartrosis que acuden a consultas de medicina familiar, así como los factores asociados con los mismos. Material y métodos. Se diseñó un estudio transversal. Por muestreo consecutivo fueron seleccionados pacientes mayores de 50 años que acudieron a consulta por dolor de rodilla y que cumplían criterios diagnósticos de gonartrosis (Sociedad Española de Reumatología), desde febrero a noviembre de 2011. A través de un protocolo específicamente diseñado se registraron variables sociodemográficas, clínicas, cuestionarios WOMAC y Lequesne, escala analógica visual de dolor, realización de radiografía de rodillas, y uso de fármacos. Resultados. Se incluyeron 86 pacientes, 70,9% mujeres, con rango de edad de 52-93 años (media: 73,7). El 96,5% tenía otras enfermedades crónicas. Tomaban analgésicos regularmente 83, con 87,9% (IC 95%:80,3-95,6) en el primer escalón analgésico de la Organización Mundial de la Salud (OMS). Los pacientes en los escalones 2 y 3 puntuaban significativamente más alto en la escala analógica visual que aquellos en el estadio 1 o que no tomaban analgésicos (media: 7,9 vs 5,9; p = 0,01). Con relación al cuestionario WOMAC existían diferencias significativas solo para 2 ítems: todos los que tomaban opioides tenían dificultad para levantarse de la cama (p = 0,001), y el 90% para levantarse del retrete (p = 0,005). El índice de Lequesne mostró un valor medio de 13,1 (DE: 4,1; rango: 3-21). Conclusiones. La gran mayoría de los pacientes con artrosis de rodilla que consultan en Atención Primaria tienen dolor fundamentalmente con el movimiento, lo que limita severamente su capacidad funcional. Los analgésicos se utilizan poco, por lo que queda un amplio margen terapéutico en estos pacientes (AU)


Introduction. Our objective was to assess the characteristics of pain, functional capacity, and pharmacological treatment in patients with knee osteoarthritis attending primary care centers and the factors associated with these characteristics. Material and methods. A cross-sectional study was performed in which patients over 50 years old consulting for knee pain and meeting diagnostic criteria for knee osteoarthritis (Spanish Rheumatology Society) were selected by consecutive sampling from February to November 2011. The following variables were recorded using a specifically designed protocol: sociodemographic and clinical variables, the WOMAC and Lequesne questionnaires, visual analog pain scale, radiographs of the knees, and drug use. Results. We included 86 patients, of whom 70.9% were women. Age ranged from 52 to 93 years (mean: 73.7) and 96.5% had other chronic diseases. Eighty three patients took analgesics regularly and 87.9% (95% CI: 80.3-95.6%) were in the first step of the World Health Organization (WHO) analgesic ladder. Patients in steps 2 and 3 scored significantly higher on the visual analog scale than those in stage 1 or not taking analgesics (mean: 7.9 vs 5.9, p = .01). The WOMAC scale showed significant differences in only two items: all those taking opioids had difficulty getting out of the bed (p = .001), and 90% had difficulty in rising from the toilet (p = .005). The Lequesne index showed a mean value of 13.1 (SD: 4.1; range 3-21). Conclusions. Most patients with knee osteoarthritis attending primary care essentially have pain on movement, severely limiting their functional capacity. Analgesics are used to a limited extent, leaving a wide therapeutic margin in these patients (AU)


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/diagnóstico , Osteoartritis de la Rodilla/rehabilitación , Manejo del Dolor/métodos , Manejo del Dolor , Dolor/tratamiento farmacológico , Dolor/rehabilitación , Dimensión del Dolor , Dimensión del Dolor/métodos , Evaluación de la Discapacidad , Estudios Transversales , Encuestas y Cuestionarios
10.
J Investig Allergol Clin Immunol ; 24(3): 154-61, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25011352

RESUMEN

BACKGROUND AND OBJECTIVE: The orodispersible house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (ALK, Denmark) is being developed for the treatment of HDM respiratory allergic disease. The objective of the 2 phase I trials was to investigate tolerability and the acceptable dose range of HDM SLIT-tablet treatment in adults and children with HDM respiratory allergic disease. PATIENTS AND METHODS: The trials were randomized, multiple-dose, dose-escalation, double-blind, placebo-controlled phase I trials including patients with HDM-induced asthma, with or without rhinoconjunctivitis. Both trials were registered in EudraCT (Trial 1: 2005-002151-41; Trial 2: 2007-000402-67). Trial 1 included 71 adults (18-63 years) and trial 2 included 72 children (5-14 years). Both trials included 6 dose groups that were randomized 3:1 to active treatment or placebo once daily for 28 days. Adverse events (AEs) were coded in MedDRA (version 8.1 or later). Immunological variables included specific IgE and IgE-blocking factor. RESULTS: No serious AEs were reported. In trial 1 (maximum dose, 32 development units [DU]), 1 patient in the 16 DU group discontinued due to AEs. The entire 32 DU group was discontinued as 1 patient had a severe adverse reaction. In trial 2 (maximum dose, 12 DU), no patients discontinued prematurely. The most frequently reported AEs were mild application-site related events. The total number of events was dose-related within each trial. HDM SLIT-tablet treatment induced changes in immunological parameters in a dose-dependent manner. CONCLUSIONS: These trials demonstrate that doses up to 12 DU of HDM SLIT-tablet were tolerated in the selected populations, and thus are suitable for further clinical investigations in adults and children with HDM respiratory allergic disease.


Asunto(s)
Hipersensibilidad/terapia , Pyroglyphidae/inmunología , Inmunoterapia Sublingual/efectos adversos , Adolescente , Adulto , Animales , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Examen Físico , Comprimidos
11.
J. investig. allergol. clin. immunol ; 24(3): 154-161, mayo.-jun. 2014. tab, ilus
Artículo en Inglés | IBECS | ID: ibc-127228

RESUMEN

Background and Objective: The orodispersible house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (ALK, Denmark) is being developed for the treatment of HDM respiratory allergic disease. The objective of the 2 phase I trials was to investigate tolerability and the acceptable dose range of HDM SLIT-tablet treatment in adults and children with HDM respiratory allergic disease. Patients and Methods: The trials were randomized, multiple-dose, dose-escalation, double-blind, placebo-controlled phase I trials including patients with HDM-induced asthma, with or without rhinoconjunctivitis. Both trials were registered in EudraCT (Trial 1: 2005-002151-41; Trial 2: 2007-000402-67). Trial 1 included 71 adults (18-63 years) and trial 2 included 72 children (5-14 years). Both trials included 6 dose groups that were randomized 3:1 to active treatment or placebo once daily for 28 days. Adverse events (AEs) were coded in MedDRA (version 8.1 or later). Immunological variables included specific IgE and IgE-blocking factor. Results: No serious AEs were reported. In trial 1 (maximum dose, 32 development units [DU]), 1 patient in the 16 DU group discontinued due to AEs. The entire 32 DU group was discontinued as 1 patient had a severe adverse reaction. In trial 2 (maximum dose, 12 DU), no patients discontinued prematurely. The most frequently reported AEs were mild application-site related events. The total number of events was dose-related within each trial. HDM SLIT-tablet treatment induced changes in immunological parameters in a dose-dependent manner. Conclusions: These trials demonstrate that doses up to 12 DU of HDM SLIT-tablet were tolerated in the selected populations, and thus are suitable for further clinical investigations in adults and children with HDM respiratory allergic disease (AU)


Introducción y Objetivo: La tableta orodispersable para inmunoterapia sublingual del ácaro del polvo de casa (SLIT-tablet) se ha desarrollado para el tratamiento de la alergia respiratoria frente al ácaro. El objetivo de la fase I de estos 2 ensayos clínicos fue investigar la tolerancia y el rango de aceptación de la dosis de tratamiento en adultos y niños con alergia respiratoria al ácaro del polvo de casa. Los ensayos randomizados, con dosis múltiple escalonada, doble ciego controlados con placebo incluyeron a pacientes con asma inducida por el ácaro del polvo de casa, con o sin rinoconjuntivitis. Se registraron en EudraCT (Ensayo 1: 2005-002151-41; Ensayo 2: 2007-000402-67). Pacientes y Métodos: El ensayo 1 incluyó a 71 pacientes adultos (18-63 años) y el ensayo 2 incluyó a 72 niños (5-14 años). Ambos ensayos clínicos incluían 6 grupos de dosis que fueron randomizados 3:1 para tratamiento activo o placebo, una vez al día durante 28 días. Las reacciones adversas (RAs) fueron codificadas en MedDRA (versión 8.1 or later). Las variables inmunológicas incluían IgE específica y factor bloqueante de la IgE. No se registraron RAs importantes. En el ensayo 1 (con la dosis máxima y 32 unidades de desarrollo [UD])un paciente del grupo 16-UD tuvo que dejar el tratamiento por RAs. El grupo 32-UD completo abandonó el tratamiento debido a que un paciente manifestó RAs graves. Resultados: En el ensayo 2 (dosis máxima ,12 UD) ningún paciente abandonó el tratamiento de forma prematura. Las RAs más frecuentemente registradas fueron de tipo local relacionadas con el lugar de aplicación del tratamiento. El número total de reacciones estaba relacionado con la dosis administrada en cada ensayo. Por otra parte, este tratamiento indujo cambios en los parámetros inmunológicos de forma dosis-dependiente. Conclusiones: Estos ensayos demuestran que el aumento de dosis por encima de 12 UD se tolera bien en las poblaciones estudiadas en estos ensayos, dato a tener en cuenta para futuras investigaciones en adultos y niños con alergia respiratoria por polvo de casa (AU)


Asunto(s)
Humanos , Masculino , Femenino , Niño , Adulto , Pyroglyphidae , Pyroglyphidae/inmunología , Inmunoterapia/tendencias , Ensayos Clínicos Fase I como Asunto/métodos , Ensayos Clínicos Fase I como Asunto , Hipersensibilidad/epidemiología , Hipersensibilidad/prevención & control
12.
Appl Radiat Isot ; 87: 336-41, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24332343

RESUMEN

The aim of the study was to check for equivalence of computer codes that can perform calculations of true coincidence summing correction factors. All calculations were performed for a set of well-defined detector and sample parameters, without any reference to empirical data. For a p-type detector model the application of different codes resulted in satisfactory agreement in the calculated correction factors. For high-efficiency geometries in combination with an n-type detector and a radionuclide emitting abundant X-rays the results were scattered.

13.
Toxicol In Vitro ; 27(1): 441-50, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22906570

RESUMEN

Skin irritation evaluation is an important endpoint for the safety assessment of cosmetic ingredients required by various regulatory authorities for notification and/or import of test substances. The present study was undertaken to investigate possible protocol adaptations of the currently validated in vitro skin irritation test methods based on reconstructed human epidermis (RhE) for the testing of plant extracts and natural botanicals. Due to their specific physico-chemical properties, such as lipophilicity, sticky/buttery-like texture, waxy/creamy foam characteristics, normal washing procedures can lead to an incomplete removal of these materials and/or to mechanical damage to the tissues, resulting in an impaired prediction of the true skin irritation potential of the materials. For this reason different refined washing procedures were evaluated for their ability to ensure appropriate removal of greasy and sticky substances while not altering the normal responses of the validated RhE test method. Amongst the different procedures evaluated, the use of a SDS 0.1% PBS solution to remove the sticky and greasy test material prior to the normal washing procedures was found to be the most suitable adaptation to ensure efficient removal of greasy and sticky in-house controls without affecting the results of the negative control. The predictive capacity of the refined SDS 0.1% washing procedure, was investigated by using twelve oily and viscous compounds having known skin irritation effects supported by raw and/or peer reviewed in vivo data. The normal washing procedure resulted in 8 out of 10 correctly predicted compounds as compared to 9 out of 10 with the refined washing procedures, showing an increase in the predictive ability of the assay. The refined washing procedure allowed to correctly identify all in vivo skin irritant materials showing the same sensitivity as the normal washing procedures, and further increased the specificity of the assay from 5 to 6 correct predictions out of 7 non irritants as compared to the normal washing procedures. In addition, when exposed to non-irritant oily and viscous materials, tissues rinsed with 0.1% SDS generally showed increased viabilities accompanied by decreased variabilities as compared to the normal washing procedures. Similar results were obtained when testing typical in-house natural botanical ingredients. In conclusion, the use of a refined washing procedure making use of SDS 0.1% in PBS was found a suitable procedure to ensure efficient removal of greasy and sticky materials, leading to an increased predictive capacity and decreased variability of the tissue responses while maintaining its sensitivity and not affecting untreated tissues morphology and viability.


Asunto(s)
Alternativas a las Pruebas en Animales/métodos , Irritantes/toxicidad , Extractos Vegetales/toxicidad , Pruebas de Irritación de la Piel/métodos , Detergentes/química , Dimetilsulfóxido/química , Epidermis/efectos de los fármacos , Humanos , Técnicas In Vitro , Irritantes/química , Aceite Mineral/química , Extractos Vegetales/química , Cloruro de Sodio/química , Solventes/química , Viscosidad
14.
Environ Monit Assess ; 185(6): 5019-29, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23054286

RESUMEN

This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities ((40)K, (137)Cs, (210)Pb, (226)Ra, (228)Ac, (234)Th and (212)Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess (210)Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles.


Asunto(s)
Estuarios , Inundaciones , Sedimentos Geológicos/química , Metales/análisis , Radioisótopos/análisis , Contaminantes del Agua/análisis , Monitoreo del Ambiente , Marruecos
15.
Neuroscience ; 210: 47-57, 2012 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-22426237

RESUMEN

The epidermis can be considered as a sensory organ. Sensory neurons of the peripheral nervous system send many primary afferent fibers to the skin, creating a dynamic communication with epidermal cells. However, little is known about the functional interactions between the sensory fibers and the keratinocytes. It is therefore difficult to reproduce these interactions in vitro. We have developed an in vitro model based on the coculture of primary human keratinocytes and the dorsal root ganglion cell line F-11. F-11 cells have been classically used to mimic authentic peptidergic nociceptive neurons. We first investigated the morphological and functional characteristics of F-11 cells cultured in basal keratinocyte medium and then analyzed the influence of keratinocytes on these properties. We found that F-11 cells survived and differentiated well in this medium. Therefore, the addition of neurotrophins did not enhance their survival or differentiation. These neurons expressed sensory neuron markers and were able to release neuropeptides after capsaicin activation. We noted that neuropeptides release were obtained even at a low calcium concentration and that axonal outgrowth was not influenced by external calcium (Ca(2+)) levels. These properties were reproduced when F-11 cells were cocultured with keratinocytes, but they had no significant influence on axonal development or neuropeptide release. In this study, we describe for the first time the culture of F-11 neurons with another cell type. This coculture model in which keratinocytes and neurons are maintained in low Ca(2+) concentrations may be a useful in vitro alternative for studying and characterizing the close communication between keratinocytes and sensory neurons.


Asunto(s)
Técnicas de Cocultivo/métodos , Queratinocitos/citología , Queratinocitos/metabolismo , Neuronas/citología , Neuronas/metabolismo , Animales , Diferenciación Celular , Línea Celular , Supervivencia Celular , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Humanos , Inmunohistoquímica , Ratones , Neuropéptidos/biosíntesis
16.
Appl Radiat Isot ; 70(9): 2112-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22445105

RESUMEN

The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of (152)Eu and (134)Cs, and different source-to-detector distances. They are presented and discussed.


Asunto(s)
Algoritmos , Artefactos , Radioisótopos/análisis , Radioisótopos/normas , Radiometría/métodos , Radiometría/normas , Espectrometría gamma/métodos , Semivida , Internacionalidad , Dosis de Radiación , Radioisótopos/química , Estándares de Referencia , Valores de Referencia
17.
J Hazard Mater ; 205-206: 198-207, 2012 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-22230754

RESUMEN

This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and 206Pb/207Pb/208Pb, 238U/234U and 232Th/230Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA® extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.


Asunto(s)
Plomo/análisis , Torio/análisis , Uranio/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Radiactivos del Agua/análisis , Fraccionamiento Químico , Monitoreo del Ambiente/instrumentación , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Isótopos/análisis , Espectrometría de Masas/métodos , Metales/análisis
18.
Mutat Res ; 743(1-2): 36-41, 2012 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-22266475

RESUMEN

Currently, the cosmetics industry relies on the results of in vitro genotoxicity tests to assess the safety of chemicals. Although the cytokinesis-block micronucleus (CBMN) test for the detection of cells that have divided once is routinely used and currently accepted by regulatory agencies, it has some limitations. Reconstituted human epidermis (RHE) is widely used in safety assessments because its physiological properties resemble those of the skin, and because it allows testing of substances such as hydrophobic compounds. Thus, the micronucleus test is being adapted for application in RHE-reconstructed tissues. Here we investigated whether two different reconstructed epidermis models (EPI/001 from Straticell, and RHE/S/17 from Skinethic) are suitable for application of the micronucleus test. We found that acetone does not modify micronucleus frequency, cell viability, and model structure, compared with non-treated RHE. Treatment of the EPI/001 model with mitomycin C and vinblastine resulted in a dose-dependent increase of micronucleus frequency as well as a decrease of tissue viability and of binucleated cell rate, while no changes of the epidermal structure were observed. The number of binucleated cells obtained with the RHE/S/17 model was too small to permit micronucleus testing. These results indicate that the proliferative rate of the tissue used is a critical parameter in performing the micronucleus test on a 3D model.


Asunto(s)
Compuestos de Bencidrilo , Clorhidrinas , Epidermis , Pruebas de Micronúcleos/métodos , Ingeniería de Tejidos , Acetona/farmacología , Citocalasina B/toxicidad , Epidermis/efectos de los fármacos , Humanos , Mitomicina/toxicidad , Ingeniería de Tejidos/métodos , Vinblastina/toxicidad
19.
Rev. chil. radiol ; 18(4): 157-162, 2012. ilus, tab
Artículo en Español | LILACS | ID: lil-665604

RESUMEN

Objective. To validate the utility of 4D Blood Flow and Navier-Stokes equations to create relative pressure (RP) maps in the aorta and pulmonary artery (PA) in healthy volunteers and patients with repaired tetralogy of Fallot (TOF). Methods. A 4D flow sequence of whole heart and its major vessels was acquired in 10 healthy volunteers and 6 patients with repaired TOF. The root of the ascending aorta was used as the reference point to calculate RP along five different points of this area. In addition, relative pressure of both right and left PA was measured as correlated to absolute pressure. Results. Patients with repaired TOF showed greater pulmonary artery (PA) relative pressure differences between maximum and minimum values when compared to volunteers (p <0.05). Additionally, aortic relative pressures had an excellent correlation with published data, whether using 4D flow or by catheterization. Conclusions. 4D Flow MRI may represent a new non-invasive and non operator-dependent diagnostic tool in CV disease management.


Objetivo. Utilizar 4D Flow y las ecuaciones de Navier-Stokes para obtener mapas de presiones relativas (PR) en la Aorta y Arteria Pulmonar (AP) de voluntarios y pacientes con Tetralogía de Fallot reparada (TOFr). Métodos. En 10 voluntarios y 6 pacientes con TOFr se adquirió la secuencia 4D flow del corazón y sus principales vasos. La raíz de la Aorta Ascendente se utilizó como referencia para calcular las PR a esta zona en cinco puntos distintos. Además, se midió la PR de la AP derecha e izquierda respecto a la AP. Resultados. Los pacientes con TOFr tuvieron diferencias de PR entre los valores máximos y mínimos más grandes que los voluntarios en la AP (p<0,05). Adicionalmente, las PR de la aorta tuvieron una excelente correlación con datos publicados utilizando 4D flow y mediante cateterización. Conclusiones. 4D Flow podría constituir una nueva herramienta diagnóstica, no invasiva, ni operador dependiente, en el manejo de patologías CV.


Asunto(s)
Persona de Mediana Edad , Aorta Torácica/fisiopatología , Arteria Pulmonar/fisiopatología , Imagen por Resonancia Magnética , Tetralogía de Fallot/fisiopatología , Velocidad del Flujo Sanguíneo , Presión
20.
Mar Pollut Bull ; 62(7): 1521-9, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21529854

RESUMEN

After the termination of phosphogypsum discharges to the Huelva estuary (SW Spain), a unique opportunity was presented to study the response of a contaminated environmental compartment after the cessation of its main source of pollution. The evolution over time of uranium concentrations in the estuary is presented to supply new insights into the decontamination of a scenario affected by Naturally Occurring Radioactive Material (NORM) discharges. The cleaning of uranium isotopes from the area has not taken place as rapidly as expected due to leaching from phosphogypsum stacks. An in-depth study using various techniques of analysis, including (234)U/(238)U and (230)Th/(232)Th ratios and the decreasing rates of the uranium concentration, enabled a second source of uranium contamination to be discovered. Increased uranium levels due to acid mine drainage from pyrite mines located in the Iberian Pyrite Belt (SW Spain) prevent complete uranium decontamination and, therefore, result in levels nearly twice those of natural background levels.


Asunto(s)
Hierro/análisis , Minería , Sulfuros/análisis , Uranio/análisis , Contaminantes Radiactivos del Agua/análisis , Sulfato de Calcio/análisis , Agua Dulce/química , Sedimentos Geológicos/química , Fósforo/análisis , Monitoreo de Radiación , Agua de Mar/química
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