A range of nonheme oxo-iron(IV) model systems with tetra- or pentadentate ligands is shown to produce methane from methionine and other thioethers. This model reaction for the natural aerobic production of methane is shown to proceed via two sulfoxidation steps involving the oxo-iron(IV) complexes, with a bifurcation in the second step that either produces the sulfone or leads to demethylation with similar probabilities. In the presence of O , the resulting methyl radicals produce methanol and formate or, in an O -depleted environment, lead to formation of methane.
View Article and Find Full Text PDFThe skin on the lower legs of 25 female subjects was evaluated first in the winter, and then again in the summer of the same subjects. Barrier function was determined by measuring transepidermal water loss (TEWL), and skin hydration and dryness were evaluated by electrical measurements (Corneometer ® CM825) and visual grading. Stratum corneum (SC) was sampled using 10 sequential D-Squame sampling discs and analyzed for 2-pyrrolidone-5-carboxylic acid (PCA), keratin-1,10,11, interleukin 1α (IL-1α), interleukin 1 receptor antagonist (IL-1ra), selected ceramides, cholesterol, cholesterol sulfate, and selected free fatty acids.
View Article and Find Full Text PDFMethane in the environment is produced by both biotic and abiotic processes. Biomethanation involves the formation of methane by microbes that live in oxygen-free environments. Abiotic methane formation proceeds under conditions at elevated temperature and/or pressure.
View Article and Find Full Text PDFObjectives: Although the mechanisms of sweating due to thermoregulation vs. stress are distinct, the antiperspirant industry focuses primarily on perspiration due to heat as their method of efficacy testing. To better understand the overall protection afforded by a 'Clinical Strength' over-the-counter antiperspirant product, we compare results from a standard hot-room study with results from two studies using the Trier Social Stress Test (TSST).
View Article and Find Full Text PDFBackground: Individuals with axillary hyperhidrosis have much higher than average sweat rates and are often prescribed anhydrous aluminum chloride (AlCl(3)) solutions. Topical application of these solutions can be irritating to the skin, resulting in poor compliance and lower than desired efficacy.
Objective: Demonstrate the efficacy of an over the counter "clinical strength" soft-solid antiperspirant using a night time application regimen and compare to a prescription aluminum chloride (6.