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1.
Sci Total Environ ; 637-638: 1137-1149, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-29801207

RESUMEN

The Rim Fire was one of the largest wildfires in California history, burning over 250,000 acres during August and September 2013 affecting air quality locally and regionally in the western U.S. Routine surface monitors, remotely sensed data, and aircraft based measurements were used to assess how well the Community Multiscale Air Quality (CMAQ) photochemical grid model applied at 4 and 12 km resolution represented regional plume transport and chemical evolution during this extreme wildland fire episode. Impacts were generally similar at both grid resolutions although notable differences were seen in some secondary pollutants (e.g., formaldehyde and peroxyacyl nitrate) near the Rim fire. The modeling system does well at capturing near-fire to regional scale smoke plume transport compared to remotely sensed aerosol optical depth (AOD) and aircraft transect measurements. Plume rise for the Rim fire was well characterized as the modeled plume top was consistent with remotely sensed data and the altitude of aircraft measurements, which were typically made at the top edge of the plume. Aircraft-based lidar suggests O3 downwind in the Rim fire plume was vertically stratified and tended to be higher at the plume top, while CMAQ estimated a more uniformly mixed column of O3. Predicted wildfire ozone (O3) was overestimated both at the plume top and at nearby rural and urban surface monitors. Photolysis rates were well characterized by the model compared with aircraft measurements meaning aerosol attenuation was reasonably estimated and unlikely contributing to O3 overestimates at the top of the plume. Organic carbon was underestimated close to the Rim fire compared to aircraft data, but was consistent with nearby surface measurements. Periods of elevated surface PM2.5 at rural monitors near the Rim fire were not usually coincident with elevated O3.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Modelos Químicos , Incendios Forestales , Contaminación del Aire/estadística & datos numéricos , Aeronaves , California , Modelos Teóricos , Ozono , Imágenes Satelitales
2.
Appl Radiat Isot ; 116: 69-76, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27501137

RESUMEN

A code called EXVol has been developed to obtain the absolute peak efficiency for an extended or voluminous γ-ray source. The method is based on the concept of effective solid angles. Several efficiency curves that have been determined semi-empirically for voluminous sources are compared with the experimental values based on certified reference volume sources. To study the geometric and matrix effects, standard γ-ray sources of several media, volumes and shapes were measured using HPGe detectors with three different efficiencies. For the n-type detector of 32% relative efficiency, the relative deviations are less than ±10%; this performance is similar to that of existing programs for similar purposes. The EXVol code is able to calculate the detection efficiency within approximately five minutes or less. Systematic errors based on EXVol input parameters, which are mainly due to the inherent uncertainty in the detector's characteristic dimensions provided by the vendor, are studied to obtain more accurate specifications of the detectors.

3.
Skin Res Technol ; 20(1): 87-91, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23815476

RESUMEN

PURPOSE: People with dry skin (xerosis) are common in community pharmacies, but there is no consistent guidance for community pharmacists to evaluate and alleviate dry skin. Through evaluating any difference of the clinical scoring systems of EEMCO guidance between a dermatologist and pharmacists and the efficacy of moisturizers for the treatment of dry skin recommended by community pharmacists, we aim to validate a dry skin guidance through the help of community pharmacists. These results provide insight into how community pharmacists can help patients with dry skin. METHODS: The clinical scoring systems of EEMCO guidance used in this study comprised analog scales, the overall dry skin score (ODS), and the specific symptom sum score (SRRC) system. All pictures of the dry skin scored by pharmacists were visually evaluated by a dermatologist. The efficacy of the moisturizers was determined by the difference of the scales on day 0 and on day 28. RESULTS: In this study, 387 patients with dry skin from 157 community pharmacies were evaluated by pharmacists. Visual scale with divisions, ODS and SRRC that were evaluated by pharmacists on day 0 and day 28 were moderately reliable by a dermatologist. All parameters of dry skin were significantly improved by the moisturizers which were recommended by community pharmacists on day 28. CONCLUSION: Visual scale, ODS and SRRC can be generally measured to evaluate dry skin in community pharmacies with moderate degree of reliability. This finding has possible applications for investigating the assessment of the community pharmacists on clinical scoring system of dry skin and moisturizers.


Asunto(s)
Dermatología/normas , Farmacias/normas , Examen Físico/normas , Guías de Práctica Clínica como Asunto , Crema para la Piel/farmacología , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/tratamiento farmacológico , Adulto , Relación Dosis-Respuesta a Droga , Europa (Continente) , Femenino , Humanos , Corea (Geográfico) , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Enfermedades de la Piel/clasificación , Resultado del Tratamiento , Escala Visual Analógica
4.
Appl Radiat Isot ; 68(4-5): 566-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19819152

RESUMEN

Thermal analysis was performed for a titanium drive-in target of a D-D neutron generator. Computational fluid dynamics code CFX-5 was used in this study. To define the heat flux term for the thermal analysis, beam current profile was measured. Temperature of the target was calculated at some of the operating conditions. The cooling performance of the target was evaluated by means of the comparison of the calculated maximum target temperature and the critical temperature of titanium.


Asunto(s)
Modelos Químicos , Titanio/química , Titanio/efectos de la radiación , Simulación por Computador , Neutrones , Dosis de Radiación , Dispersión de Radiación , Temperatura
5.
Appl Radiat Isot ; 67(6): 1094-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19237287

RESUMEN

Characteristics of the dead time of a Geiger-Müller (GM) counter was studied by using a decaying source method and tests were performed for two-parameter dead time models including the general models. Activated (56)Mn was used as the decaying source and the counting rates were observed in one minute steps for 20 half-lives using a GM probe and a multichannel scaler. Measured data were compared with predictions of a generalized dead time model, a dead time model of nonextending-extending (NE-E) types, and a model of extending-nonextending (E-NE) types in series. The NE-E series model described the measured counting rates better than the other models. The model rates were consistent with the data within 10% up to a true rate of approximately 10 kcps, however, its application in the region of higher counting rates was limited. Possible causes of this limitation are discussed. For practical purposes, a phenomenological model is suggested to describe measured counting rates above approximately 10 kcps.


Asunto(s)
Radiometría/normas , Falla de Equipo
6.
Int J Radiat Biol ; 82(4): 285-91, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16690596

RESUMEN

PURPOSE: There are only a few reports on harmful effects of 20 kHz sine waves; however, it is essential to comprehensively evaluate the potentially harmful effect of triangular signals at the same frequency. Therefore, in this study, effects of long-term exposure to 20 kHz magnetic fields was examined. MATERIALS AND METHODS: Eighty Sprague Dawley rats were divided into two groups (half male and female in each sham and exposed groups), and they were exposed to 20 kHz triangular magnetic fields at 6.25 microT rms for 8 h/day for 12 or 18 months. Urinalysis [pH, glucose, protein, ketone bodies, red blood cells (RBC), nitrogen, bilirubin, urobilinogen, and specific gravity], hematological analysis (RBC, hemoglobin, hematocrit, thrombocyte count, and leucocyte count), blood biochemistry (total protein, blood urea nitrogen, creatinine, glucose, total bilirubin, total cholesterol, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase), and histopathological analysis of organs (thymus, stomach, intestine, liver, kidney, testis, ovary, spleen, brain, heart, and lung) were performed. RESULTS: No significant differences were seen between 20 kHz magnetic-fields exposed rats and sham-exposed rats in body and organ weights, hematological analysis, blood biochemistry, urinalysis data, and histopathological examination, except for the numbers of neutrophiles and lymphocytes in female rats. The number of neutrophiles was significantly increased in female rats on the 12th month after exposure, and the number of lymphocytes in female rats was significantly decreased on the 18th month. CONCLUSION: Long-term exposure of rats to 20 kHz triangular magnetic fields did not induce any significantly harmful effects, except changes in neutrophiles at 12 months and lymphocytes at 18 months of exposure in female rats. These hematological changes need to be investigated again at a higher intensity of 20 kHz magnetic fields.


Asunto(s)
Células Sanguíneas/efectos de la radiación , Proteínas Sanguíneas/análisis , Peso Corporal/efectos de la radiación , Campos Electromagnéticos/efectos adversos , Tamaño de los Órganos/efectos de la radiación , Irradiación Corporal Total/efectos adversos , Animales , Células Sanguíneas/patología , Carga Corporal (Radioterapia) , Femenino , Masculino , Especificidad de Órganos , Dosis de Radiación , Ratas , Ratas Sprague-Dawley , Medición de Riesgo , Factores de Riesgo , Vísceras/patología , Vísceras/efectos de la radiación
7.
Appl Radiat Isot ; 58(2): 227-33, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12573322

RESUMEN

The sum-peak method was applied to calibrate four 60Co sources in the range of 25-350kBq. An HPGe-based gamma-ray spectroscopy system was used, and the effects of the angular correlation and pulse pile-up were corrected, and are discussed. The correction for the angular correlation was obtained from a theoretical calculation, while the pulse pile-up effect was corrected using a new extrapolation technique based on the pile-up measurements by varying the shaping time of the amplifier. The determined radioactivities were within 2% deviation from the values reported by the supplier and the associated uncertainties were less than 2%. The observed consistency was obtained under the experimental condition of keeping the total counting rate

8.
Lipids ; 36(4): 427-9, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11383697

RESUMEN

A new diacylgalactolipid was isolated from the marine cyanobacterium Oscillatoria sp., and the structure was elucidated as (2S)-3-O-beta-D-galactopyranosyl-1-O-(9Z,12Z-oc-tadecadienoyl)-2-O-(4Z-hexadecenoyl)glycerol by enzymatic partial hydrolysis using lipase and physicochemical evidence, which included determining the double bond position in the hexadecenoic acid moiety.


Asunto(s)
Cianobacterias/química , Galactolípidos , Glucolípidos/química , Fenómenos Químicos , Química Física , Ácidos Grasos/análisis , Cromatografía de Gases y Espectrometría de Masas , Glucolípidos/aislamiento & purificación , Hidrólisis , Lipasa/metabolismo , Espectroscopía de Resonancia Magnética , Espectrometría de Masa Bombardeada por Átomos Veloces
9.
Nat Prod Lett ; 15(5): 299-306, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11841113

RESUMEN

Two new galactopyranosyldiacylglycerols have been isolated from the marine bacillariophycean microalga Nitzschia sp. and their structures were determined as (2S)-3-O-beta-D-galactopyranosyl-1,2-di-O-(9Z-hexadecenoyl)glycerol (1) and (2S)-3-O-beta-D-galactopyranosyl-1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-O-(9Z-hexadecenoyl)glycerol (2) by physicochemical evidence.


Asunto(s)
Glucolípidos/aislamiento & purificación , Glucolípidos/metabolismo , Fitoplancton/química , Cromatografía Líquida de Alta Presión , Ácidos Docosahexaenoicos/química , Ácidos Docosahexaenoicos/metabolismo , Ecosistema , Ácidos Eicosanoicos/química , Ácidos Eicosanoicos/metabolismo , Galactolípidos , Galactosa/química , Cromatografía de Gases y Espectrometría de Masas , Glucolípidos/química , Hidrólisis , Corea (Geográfico) , Lipasa/metabolismo , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Espectrofotometría Infrarroja , Estereoisomerismo , Ácido alfa-Linolénico/química , Ácido alfa-Linolénico/metabolismo
10.
Arch Pharm Res ; 23(5): 438-40, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11059818

RESUMEN

The total synthesis of a demethoxy-egonol isolated from Styrax obassia, 5-(3-hydroxypropyl)-2-(3',4'-methylenedioxyphenyl)benzofuran (9), is described. The key steps involve the construction of a 2-arylbenzofuran skeleton 7 from methyl 3-(4-hydroxyphenyl)propionate with 2-chloro-2-methylthio-(3',4'-methylenedioxy)acetophenone (6) in the presence of ZnCl2 and successive desulfurization of the resulting product 7.


Asunto(s)
Benzofuranos/síntesis química , Plantas Medicinales
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