25 research outputs found

    Characterizing generated charged inverse micelles with transient current measurements

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    We investigate the generation of charged inverse micelles in nonpolar surfactant solutions relevant for applications such as electronic ink displays and liquid toners. When a voltage is applied across a thin layer of a nonpolar surfactant solution between planar electrodes, the generation of charged inverse micelles leads to a generation current. From current measurements it appears that such charged inverse micelles generated in the presence of an electric field behave differently compared to those present in equilibrium in the absence of a field. To examine the origin of this difference, transient current measurements in which the applied voltage is suddenly increased are used to measure the mobility and the amount of generated charged inverse micelles. The mobility and the corresponding hydrodynamic size are found to be similar to those of charged inverse micelles present in equilibrium, which indicates that other properties determine their different behavior. The amplitude and shape of the transient currents measured as a function of the surfactant concentration confirm that the charged inverse micelles are generated by bulk disproportionation. A theoretical model based on bulk disproportionation with simulations and analytical approximations is developed to analyze the experimental transient currents

    Cost-effectiveness of six strategies for Helicobacter pylori diagnosis and management in uninvestigated dyspepsia assuming a high resource intensity practice pattern

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    <p>Abstract</p> <p>Background</p> <p>Initial assessment of dyspepsia often includes noninvasive testing for <it>Helicobacter pylori </it>infection. Commercially available tests vary widely in cost and accuracy. Although there is extensive literature on the cost-effectiveness of <it>H. pylori </it>treatment, there is little information comparing the cost-effectiveness of various currently used, noninvasive testing strategies.</p> <p>Methods</p> <p>A Markov simulation was used to calculate cost per symptom-free year and cost per correct diagnosis. Uncertainty in outcomes was estimated using probabilistic sensitivity analysis.</p> <p>Results</p> <p>Under the baseline assumptions, cost per symptom-free year was 122forempiricprotonpumpinhibitor(PPI)trial,andcostsforthenoninvasiveteststrategiesrangedfrom122 for empiric proton pump inhibitor (PPI) trial, and costs for the noninvasive test strategies ranged from 123 (stool antigen) to $129 (IgG/IgA combined serology). Confidence intervals had significant overlap.</p> <p>Conclusions</p> <p>Under our assumptions for how testing for <it>H. pylori </it>infection is employed in United States medical practice, the available noninvasive tests all have similar cost-effectiveness between one another as well as with empiric PPI trial.</p

    Epidemiology and cost-analysis of emergency department patients treated following traffic accidents in Iran: A retrospective cross-sectional study

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    Introduction: Epidemiological analysis of traffic accidents can provide information for future plans to lower the cost and burden of road traffic accidents (RTAs). This study was aimed to determine the epidemiological characteristics of patients with RTAs. Methods: We conducted a retrospective cross-sectional study of RTA patients presenting in 2016 to the Emergency Department at Shahid Bahonar Medical Education Center in Kerman, Iran. A checklist including variables such as age, sex, month, in which the patient referred, final outcome, overall cost and the site of injury used to collect data. The diagnostic criteria were in accordance to ICD 10. Results: Of the total of 3277 patients who were studied, 2713 (82.78) were men and 564 (16.66) were women. Most of the accidents occurred at the age group of 16-30 years and the average cost of treatment in the hospital was 2152.45 USD. The most affected area was the lower limb. The majority of accidents occurred in spring and summer. The mortality rate was (2.74). Discussion: Injuries and deaths due to RTAs are a major public health problem, especially in young age groups. Therefore, more preventive programs targeting young adults should be considered to reduce the burden of RTAs. Conclusion: Epidemiology and cost analysis of results showed that men caused more accidents and costs burden for both health system and society. Considering they have a more share of activity, economy and workforce, it will cause more damage and adverse consequences for economy and social life of the society. © 2020 International Journal of Critical Illness and Injury Science | Published by Wolters Kluwer - Medknow 177

    A Fourier transform infrared spectroscopy‐based method for tracking diffusion in organogels

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    Organogels possess characteristics that make them promising materials for enhancing our understanding of nanostructure‐diffusion relationships in gels and for use in diffusion‐centered applications including drug delivery and nanoreactor media. Unlike hydrogels, however, there are no well‐recognized techniques for measuring the fundamental diffusion parameter of diffusivity, D , in organogels. The present work establishes a technique for measuring D based upon Fourier‐transform infrared spectroscopy. Physically crosslinked gels composed of poly[styrene‐b ‐(ethylene‐butylene)‐b ‐styrene] and aliphatic mineral oil are used to showcase the new technique\u27s capability. Diffusivity of unimers—oleic acid—and reverse micelles—sodium dioctyl sulfosuccinate (AOT)—within as‐prepared and preswollen gels is quantified and resultant values are commensurate with studies of unimer and micelle diffusion in hydrogels. The case of AOT diffusion is further validated through small‐angle X‐ray scattering analysis, which is in close agreement (\u3c20% difference)
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