Cutaneous hyperpigmentation is a common disorder due to excess melanin production by the enzyme tyrosinase. The gold standard for treatment is hydroquinone (HQ), which reduces pigmentation through its toxicity to melanocytes rather than via tyrosinase inhibition. We screened an internal library for oligopeptides that inhibited both mushroom and human tyrosinase but showed no cytotoxicity to hum...

Poly(vinylferrocenium) perchlorate-poly(3,3’-diaminobenzidine) (PVFClO4 -PDAB) composite film was synthesized electrochemically for the first time on Pt disc electrode in a dichloromethane solution containing poly(vinylferrocene) (PVF) polymer, 3,3’-diaminobenzidine (DAB) monomer and tetrabutylammonium perchlorate as supporting electrolyte. This modified electrode was characterized using cyclic...

BACKGROUND Age-related macular degeneration (AMD) is the leading cause of legal blindness in the elderly population. Debris (termed drusen) below the retinal pigment epithelium (RPE) have been recognized as a risk factor for dry AMD and its progression to wet AMD, which is characterized by choroidal neovascularization (CNV). The underlying mechanism of how drusen might elicit CNV remains undefi...

The role of the endothelium in hypoxic constriction of the intact pulmonary vascular bed has not been clearly elucidated. To test for a possible role for endothelium-derived relaxing factor(s) (EDRF) in the hypoxic pressor response, isolated, whole blood-perfused rat lungs from male Sprague-Dawley rats treated with meclofenamate were prepared. Three protocols were performed, including: (a) norm...

The photosensitised degradation of 4-chlorophenol (4-CP) by iron meso-tetrakis(2,6-dichloro-3-sulfophenyl)porphyrin (FeTDCPPS) has been studied in aerated aqueous solution, and is shown to lead to formation of p-benzoquinone (BQ) and p-hydroquinone (HQ) as main photoproducts. In deaerated solution no p-benzoquinone was formed. The photolysis products were identified by high performance liquid c...

Benzene, a tobacco constituent, is a leukemogen in humans and a carcinogen in rodents. Several benzene metabolites generate superoxide anion (O(2)(.-)) and induce nitric oxide synthase in the bone marrow of mice. We hypothesized that the reaction of nitric oxide (*NO) with O(2)(.-) leads to the formation of peroxynitrite as an intermediate during benzene metabolism. This hypothesis was supporte...

Electrical sensitivity of a boron nitride nanotube (BNNT) was examined toward hydroquinone (C6H4(OH)2) molecule by using density functional theory (DFT) calculations at the B3LYP/6-31G(d) level, and it was found that the adsorption energy (Ead) of hydroquinone on the pristine nanotube is  a bout -7.77kcal/mol. But when nanotubes have been doped with Si and Al atomes, the adsorption energy of hy...

HQ-learning is a hierarchical extension of Q()-learning designed to solve certain types of partially observable Markov decision problems (POMDPs). HQ automatically decomposes POMDPs into sequences of simpler subtasks that can be solved by memoryless policies learn-able by reactive subagents. HQ can solve partially observable mazes with more states than those used in most previous POMDP work.

Melasma is a common acquired hyperpigmentation disorder disproportionately affecting women of color. Though its cause remains unknown, several predisposing risk factors have been identified. Our investigation sought to better define racial and ethnic differences in factors, treatment patterns, incidence melasma the US through large case-control analysis. We queried TriNetX database representing...