RESUMEN
Increasing trends in biomass burning emissions significantly impact air quality in North America. Enhanced mixing ratios of ozone (O3) in urban areas during smoke-impacted periods occur through transport of O3 produced within the smoke or through mixing of pyrogenic volatile organic compounds (PVOCs) with urban nitrogen oxides (NOx = NO + NO2) to enhance local O3 production. Here, we analyze a set of detailed chemical measurements, including carbon monoxide (CO), NOx, and speciated volatile organic compounds (VOCs), to evaluate the effects of smoke transported from relatively local and long-range fires on O3 measured at a site in Boulder, Colorado, during summer 2020. Relative to the smoke-free period, CO, background O3, OH reactivity, and total VOCs increased during both the local and long-range smoke periods, but NOx mixing ratios remained approximately constant. These observations are consistent with transport of PVOCs (comprised primarily of oxygenates) but not NOx with the smoke and with the influence of O3 produced within the smoke upwind of the urban area. Box-model calculations show that local O3 production during all three periods was in the NOx-sensitive regime. Consequently, this locally produced O3 was similar in all three periods and was relatively insensitive to the increase in PVOCs. However, calculated NOx sensitivities show that PVOCs substantially increase O3 production in the transition and NOx-saturated (VOC-sensitive) regimes. These results suggest that (1) O3 produced during smoke transport is the main driver for O3 increases in NOx-sensitive urban areas and (2) smoke may cause an additional increase in local O3 production in NOx-saturated (VOC-sensitive) urban areas. Additional detailed VOC and NOx measurements in smoke impacted urban areas are necessary to broadly quantify the effects of wildfire smoke on urban O3 and develop effective mitigation strategies.
RESUMEN
The Tropospheric Ozone Lidar Network (TOLNet) is a unique network of lidar systems that measure high-resolution atmospheric profiles of ozone. The accurate characterization of these lidars is necessary to determine the uniformity of cross-instrument calibration. From July to August 2014, three lidars, the TROPospheric OZone (TROPOZ) lidar, the Tunable Optical Profiler for Aerosol and oZone (TOPAZ) lidar, and the Langley Mobile Ozone Lidar (LMOL), of TOLNet participated in the "Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality" (DISCOVER-AQ)mission and the "Front Range Air Pollution and Photochemistry Éxperiment" (FRAPPÉ)to measure ozone variations from the boundary layer to the top of the troposphere. This study presents the analysis of the intercomparison between the TROPOZ, TOPAZ, and LMOL lidars, along with comparisons between the lidars and other in situ ozone instruments including ozonesondes and a P-3B airborne chemiluminescence sensor. In terms of the range-resolving capability, the TOLNet lidars measured vertical ozone structures with an accuracy generally better than ±15% within the troposphere. Larger differences occur at some individual altitudes in both the near-field and far-field range of the lidar systems, largely as expected. In terms of column average, the TOLNet lidars measured ozone with an accuracy better than ±5% for both the intercomparison between the lidars and between the lidars and other instruments. These results indicate very good measurement accuracy for these three TOLNet lidars, making them suitable for use in air quality, satellite validation, and ozone modeling efforts.
RESUMEN
The Ozone Profiling Atmospheric Lidar is a scanning four-wavelength ultraviolet differential absorption lidar that measures tropospheric ozone and aerosols. Derived profiles from the lidar data include ozone concentration, aerosol extinction, and calibrated aerosol backscatter. Aerosol calibrations assume a clear air region aloft. Other products include cloud base heights, aerosol layer heights, and scans of particulate plumes from aircraft. The aerosol data range from 280 m to 12 km with 5 m range resolution, while the ozone data ranges from 280 m to about 1.2 km with 100 m resolution. In horizontally homogeneous atmospheres, data from multiple-elevation angles is combined to reduce the minimum altitude of the aerosol and ozone profiles to about 20 m. The lidar design, the characterization of the photomultiplier tubes, ozone and aerosol analysis techniques, and sample data are described. Also discussed is a double-gating technique to shorten the gated turn-on time of the photomultiplier tubes, and thereby reduce the detection of background light and the outgoing laser pulse.
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Operatoria Dental/clasificación , Operatoria Dental/métodos , Operatoria Dental/organización & administración , Restauración Dental Permanente/clasificación , Restauración Dental Permanente/métodos , Restauración Dental Provisional/clasificación , Restauración Dental Provisional/métodos , Gutapercha/clasificación , Gutapercha/normas , Óxido de Zinc/farmacocinética , Cemento Dental , Amalgama Dental/clasificaciónAsunto(s)
Masculino , Femenino , Humanos , Adulto , Amalgama Dental/clasificación , Cemento Dental , Operatoria Dental/clasificación , Operatoria Dental/métodos , Operatoria Dental/organización & administración , Gutapercha/clasificación , Gutapercha/normas , Restauración Dental Permanente/clasificación , Restauración Dental Permanente/métodos , Restauración Dental Provisional/clasificación , Restauración Dental Provisional/métodos , Óxido de Zinc/farmacocinéticaRESUMEN
Se valoró, por medio de método doble ciego, el efecto analgésico de la administración en dosis única de pirprofén, diflunisal y zomepirac en el posoperatorio de cirugía general de 90 pacientes distribuidos en tres grupos. Las valoraciones se realizaron mediante una escala visual análoga al momento de tomar el medicamento, a los 15 y 30 minutos, y a la una, dos, tres y cuatro horas después. El efecto analgésico inmediato de pirprofén fue satisfactorio y estadísticamente superior a diflunisal y zomepirac (p=<0.01). Al final del estudio los tres medicamentos tuvieron resultados semejantes entre sí. En cuanto a la tolerancia, fue satisfactoria para los tres medicamentos
Asunto(s)
Humanos , Diflunisal/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Fenilpropionatos/uso terapéutico , Tolmetina/uso terapéutico , Ensayos Clínicos como Asunto , Método Doble CiegoRESUMEN
Treinta pacientes con heridas anfractuosas con pérdida de sustancia y no susceptibles de ser suturadas, fueron tratados tópicamente con un ungüento a base de fibrinolisina y desoxirribonucleasa. Se observó que el tejido de granulación en las heridas apareció en un promedio de cuatro días; el tiempo en que el tejido de granulación cubrió la herida fue, en promedio, de 13 días, con mínimo de ocho días. El exudado desapareció en 6.5 días como promedio. No hubo efectos secundarios. Se concluye que el medicamento acelera y favorece, en forma muy considerable, el proceso de cicatrización en este tipo de heridas, y que se trata de un compuesto eficaz como desbridante enzimático, no tóxico