30 research outputs found
Characterizing generated charged inverse micelles with transient current measurements
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
<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 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
Investigation of Various Types of Inverse Micelles in Nonpolar Liquids Using Transient Current Measurements
Immunoblotting for the serodiagnosis of Helicobacter pylori  infection in Brazilian patients with and without gastric carcinoma
Cryotherapy of cutaneous leishmaniasis caused by leishmania major in BALB/C mice: A comparative experimental study
Background & objectives: Leishmania parasites are sensitive to very low temperature. Cryotherapy is considered as an alternative to the existing pentavalent antimonials, for local treatment of cutaneous leishmaniasis (CL). Normally, liquid nitrogen (N2) at a temperature of -196 °C, is used in cryotherapy of CL, but itâs efficacy is not consistent. Recently, few studies have also reported the use of carbon dioxide (CO2) slush at -78.5 °C in CL cryotherapy. This study was aimed to evaluate the effectiveness of N2 vs CO2 cryotherapy for CL treatment in mice.
Methods: In total, 21 BALB/c mice were infected with Leishmania major strain [MRHO/IR/74/ER]. Samples were divided into three groups based on the intervention providedâSolid CO2 cryotherapy, liquid N2 cryotherapy and control group; with seven mice randomly assigned to each group. Control group received no intervention, and in the other two groups cryotherapy was used every two weeks for maximum of three months. Follow up examinations were scheduled at the time of cryotherapy, during which the size of each lesion was measured. For three mice in each study group, the spleen parasite DNA load was quantified using real-time PCR.
Results: After treatment, the liquid N2 cryotherapy showed significant reduction in size of the lesions (p = 0.029) as compared to the solid CO2 cryotherapy and control group. Also, Leishmania DNA load in spleen was significantly lower in the mice receiving liquid N2 cryotherapy (p <0.001).
Interpretation & conclusion: Liquid N2 cryotherapy is superior to CO2 cryotherapy, and it can be an effective method for controlling L. major infection. Further investigations are essential to find optimal number of treatment sessions and time intervals
Epidemiology and cost-analysis of emergency department patients treated following traffic accidents in Iran: A retrospective cross-sectional study
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. Ă© 2020 International Journal of Critical Illness and Injury Science | Published by Wolters Kluwer - Medknow 177
A Fourier transform infrared spectroscopyâbased method for tracking diffusion in organogels
Organogels possess characteristics that make them promising materials for enhancing our understanding of nanostructureâdiffusion relationships in gels and for use in diffusionâcentered applications including drug delivery and nanoreactor media. Unlike hydrogels, however, there are no wellârecognized techniques for measuring the fundamental diffusion parameter of diffusivity, D , in organogels. The present work establishes a technique for measuring D based upon Fourierâtransform infrared spectroscopy. Physically crosslinked gels composed of poly[styreneâb â(ethyleneâbutylene)âb âstyrene] and aliphatic mineral oil are used to showcase the new technique\u27s capability. Diffusivity of unimersâoleic acidâand reverse micellesâsodium dioctyl sulfosuccinate (AOT)âwithin asâprepared 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 smallâangle Xâray scattering analysis, which is in close agreement (\u3c20% difference)
Helicobacter pylori infection and typhoid fever in Jakarta, Indonesia
We evaluated the association between typhoid fever and Helicobacter pylori infection, as the latter microorganism may influence gastric acid secretion and consequently increase susceptibility to Salmonella typhi infection. Anti-H. pylori IgG and IgA antibody titres (ELISA) and gastrin concentration (RIA) were determined in the plasma of 87 blood culture-confirmed typhoid fever cases (collected after clinical recovery) and 232 random healthy controls without a history of typhoid fever, in the Jatinegara district, Jakarta. Patients with typhoid fever more often than controls were seropositive for H. pylori IgG (67% vs. 50%, P<0·008), when antibody titres were dichotomized around median titres observed in controls. H. pylori IgA seropositivity was not associated with typhoid fever. Plasma gastrin concentrations indicative of hypochlorhydria (i.e. gastrin â©Ÿ25 or â©Ÿ100 ng/l) were not significantly elevated in typhoid fever cases compared to controls (P=0·54 and P=0·27 respectively). In a multivariate analysis, typhoid fever was independently associated with young age (<33 years, median age of the controls) [odds ratio (OR) 7·93, 95% confidence interval (CI) 3·90â16·10], and H. pylori IgG seropositivity (OR 1·93, 95% CI 1·10â3·40). Typhoid fever was independently associated with H. pylori IgG seropositivity, but not with elevated gastrin concentration. Therefore, the association suggests a common risk of environmental exposure to both bacteria, e.g. poor hygiene, rather than a causal relationship via reduced gastric acid production