48 research outputs found

    Differential Optical Absorption Spectroscopy (DOAS) Measurements of Ozone in the 280--290 nm Wavelength Region

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    The differential absorption structure of the ozone spectrum between 250 and 330 nm has been investigated in order to determine the optimal wavelength region to be utilized for active differential optical absorption spectroscopy (DOAS) measurements. Considering aspects of atmospheric attenuation and interference from other species as well as the magnitude of the differential absorption cross section, an interval around 283 nm was found to be a good candidate for this application. This result was also verified during 12 months of continuous ozone monitoring in an urban environment

    A rapid and sensitive method for measuring cell adhesion

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    We have adapted the CyQuant® assay to provide a simple, rapid, sensitive and highly reproducible method for measuring cell adhesion. The modified CyQuant® assay eliminates the requirement for labour intensive fluorescent labelling protocols prior to experimentation and has the sensitivity to measure small numbers (>1000) of adherent cells

    Measurement of Aromatic-hydrocarbons With the DOAS Technique

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    Long-path DOAS (differential optical absorption spectroscopy) in the ultraviolet spectral region has been shown to be applicable for low-concentration measurements of light aromatic hydrocarbons. However, because of spectral interferences among different aromatics as well as with oxygen, ozone, and sulfur dioxide, the application of the DOAS technique for this group of components is not without problems. This project includes a study of the differential absorption characteristics, between 250 and 280 nm, of twelve light aromatic hydrocarbons representing major constituents in technical solvents used in the automobile industry. Spectral overlapping between the different species, including oxygen, ozone, and sulfur dioxide, has been investigated and related to the chemical structure of the different aromatics. Interference effects in the DOAS application due to spectral overlapping have been investigated both in quantitative and in qualitative terms, with data from a field campaign at a major automobile manufacturing plant

    Cost-effectiveness of tacrolimus ointment vs. standard treatment in patients with moderate and severe atopic dermatitis: a health-economic model simulation based on a patient survey and clinical trial data.

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    Background Atopic dermatitis (AD) affects health and quality of life (QoL) and also has great impact on both healthcare costs and costs to society. Objectives The aim of the study was to analyse the cost-effectiveness of treatment with tacrolimus ointment vs. standard treatment in patients with moderate to severe AD. Methods A Markov simulation model was constructed capturing several key features of AD and its treatment: disease severity, treatment alternatives, and QoL. The model was populated with data from three sources: (i) efficacy data from a randomized controlled trial including patients with moderate to severe AD treated with either tacrolimus ointment or standard treatment (corticosteroids), (ii) resource utilization and QoL data from a patient survey including 161 Swedish patients with AD, and (iii) official price lists. Costs were calculated according to disease severity for the two treatment alternatives using the perspective of the Swedish healthcare sector. Two analyses were performed, one based on the quantity of medication used in the trial and one based on the survey data. The relationship between effectiveness of tacrolimus ointment and the amount of medication used was tested in sensitivity analyses. Results In the model simulations patients with severe AD treated with tacrolimus ointment experienced on average 4.6 more AD-free weeks per year than patients given standard treatment. The corresponding figure for patients with moderate AD was 6.5 more AD-free weeks per year. The cost-effectiveness ratios [cost per Quality Adjusted Life Year (QALY) gained] for treatment with tacrolimus ointment vs. standard treatment were 2334 pound for moderate AD and 3875 pound for severe AD when treatment patterns from the survey were assumed, and 8269 pound for moderate AD and 12 pound 304 for severe AD when treatment patterns from the clinical trial were assumed. The results of sensitivity analyses were all well within limits to be considered cost-effective. Conclusions Estimates of the incremental cost-effectiveness ratio are far below the currently discussed threshold in Sweden, corresponding to approximately 48 pound 700 per QALY gained, and equivalent thresholds in other countries. Treatment with tacrolimus ointment in patients with moderate and severe AD can therefore be considered cost-effective

    Mercury Emissions Into the Atmosphere From A Chlor-alkali Complex Measured With the Lidar Technique

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    Data are reported on atmospheric mercury flux measured by a lidar system at a chlor-alkali plant located in central Italy. Two mercury sources were identified over the electrolytic cell rooms. A flux value of 36 g h-1 was determined during the daytime while at night the value increase to 56 g h-1. The mercury emitted into the atmosphere was found to be 4 g per 1000 kg of chlorine produced. Atmospheric mercury concentrations were supplemented with some determinations made with the point monitor technique

    Mercury degassing rate from mineralized areas in the Mediterranean basin

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    Knowledge of the natural emissions of mercury in the Mediterranean basin, which has large cinnabar anomalies, has particular weight as these deposits could be an important source of atmospheric mercury. Data on the degassing rate of mercury from soils sampled both in mineralized areas (Mt. Amiata, Italy and Almaden, Spain) and rural areas are reported. Measurements were carried out 'in situ' using a transparent flux chamber and collecting the gaseous mercury on gold collectors. The highest values were observed in Almaden over the roasted cinnabar banks (up to 100 mu g/m(2)h) from past and present mining activity. In Italian rural areas the values of the volatilization rate of mercury are on the order of few ng/m(2)h. The degassing rate was observed to be strongly dependent on the ambient temperature and not only seasonal but also daily variations were measured in all the studied areas
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