Project description:Carriage of Enterobacteriaceae producing extended spectrum beta-lactamases in kindergarten children in the Lao People’s Democratic Republic
Project description:BACKGROUND:Dermatological services in Laos, South East Asia are limited to the capital and patch testing is currently not available, so no data exists regarding the common cutaneous allergens in this population. OBJECTIVES:The aim of this study was to document positive patch tests in medical students without evidence of contact dermatitis in Laos. PATIENTS/MATERIALS/METHODS:One hundred and fifty medical students were patch tested using TRUE Test® panels 1 to 3 (35 allergens). Readings were taken at Days 2 and 4. RESULTS:Thirty-eight students (25.3%) had a positive reaction to at least one allergen, accounting for 52 reactions in total. The proportion of the students with positive patch test reading was significantly higher in the female [33/96 (34%)] than in the male [5/54 (9%)], p<0.001. The most common allergens were: nickel (10%), gold (6.6%), thiomersal (6.6%), cobalt dichloride (2%) and p-tert-Butylphenol formaldehyde resin (2%). Balsam of Peru (0.66%), black rubber mix (0.66%), Cl+Me-Isothiazolinone (0.66%), fragrance mix 1 (0.66%), quinolone mix (0.66%), methyldibromo glutaronitrile (0.66%), mercapto mix (0.66%), epoxy resin (0.66%), paraben mix (0.66%), thiuram (0.66%) and wool alcohols (0.66%) accounted for all of the other positive reactions. CONCLUSION:This study represents the first documented patch test results in Lao medical students and in the adult Lao population. The results of this study will inform any future research into contact allergy in Laos and give an insight into the background level of contact sensitivity in this population.
Project description:We study the electronic, magnetic, and optical properties of (LaO1-xFx)MnAs (x = 0, 0.0625, 0.125, 0.25) systems, calculated using the generalized gradient approximation (GGA) corrected by Hubbard energy (U) = 1 eV. For x = 0, this system shows equal bandgap (Eg) values for spin-up and spin-down of 0.826 eV, with antiferromagnetic (AFM) properties and local magnetic moment in the Mn site of 3.86 μB per Mn. By doping F with x = 0.0625, the spin-up and spin-down Eg values decrease to 0.778 and 0.798 eV, respectively. This system, along with antiferromagnetic properties, also has a local magnetic moment in the Mn site of 3.83 μB per Mn. Increasing doping F to x = 0.125 induces increases of Eg to 0.827 and 0.839 eV for spin-up and spin-down. However, the AFM remains, where μMn slightly decreases to 3.81 μB per Mn. Furthermore, the excess electron from the F ion induces the Fermi level to move toward the conduction band and changes the bandgap type from indirect bandgap (Γ → M) to direct bandgap (Γ → Γ). Increasing x to 25% induces the decrease of spin-up and spin-down Eg to 0.488 and 0.465 eV, respectively. This system shows that the AFM changes to ferrimagnetism (FIM) for x = 25%, with a total magnetic moment of 0.78 μB per cell, which is mostly contributed by Mn 3d and As 4p local magnetic moments. The change from AFM to FIM behavior results from competition between superexchange AFM ordering and Stoner's exchange ferromagnetic ordering. Pristine (LaO)MnAs exhibits high excitonic binding energy (∼146.5 meV) due to a flat band structure. Our study shows that doping F in the (LaO)MnAs system significantly modifies the electronic, magnetic, and optical properties for novel advanced device applications.