Inter/intramolecular hydrogen bonding of a series of hydroxystearic acids (HSAs) are investigated. Self-assembly of molecular gels obtained from these fatty acids with isomeric hydroxyl groups is influenced by the position of the secondary hydroxyl group. 2-Hydroxystearic acid (2HSA) does not form a molecular dimer, as indicated by FT-IR, and growth along the secondary axis is inhibited because...

Laser induced fluorescence was used for measurement of concentration of hydroxyl (OH) radicals in the plasma pencil, which is a radiofrequency plasma jet operated in argon at atmospheric pressure. The problematic of the rotational energy transfer, spectral overlap of the laser line and hydroxyl absorption line and saturation effects were treated. The method was calibrated by Rayleigh scattering...

tory conditions of the gingival and underlying bone and connective tissue. Platelet-activating factor (PAF), a potent inflammatory phospholipid mediator that has been previously detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid and in saliva, is implicated in periodontal disease. Our results from previous studies showed that the biologically active phospholi...

Zonisamide (ZNS), a commonly used anticonvulsant, scavenged hydroxyl radicals at a clinically relevant concentration. Reactants of ZNS with hydrogen peroxide and with hydrogen peroxide plus UV irradiation, yielding hydroxyl radicals, were analyzed by the LC/MS technique. Many small fragments were found in the both reactions, suggesting that ZNS was decomposed not only by hydroxyl radicals but a...

[1] Tropospheric hydroxyl (OH) is the cleaning agent of the atmosphere, because most oxidation processes are initiated by OH. If the OH chemical system were unstable, runaway growth of oxidants (autocatalytic conditions) or of reduced gases (catastrophic conditions) might occur, especially because the atmospheric composition is changing rapidly. We present simulations with a global chemistry-tr...

Various properties of crystalline papain have been under investigation in this laboratory for several years in attempts to understand the specificity, mode of action, and other aspects of the behavior of this enzyme (1). Inasmuch as papain must be in its native state to retain its enzymic activity, a knowledge of the role of the amino acid side chains in maintaining conformation is essential. T...

A new method for the determination of hydroxyl radicals is proposed. The method is based on the use of a hybrid molecule consisting of a fluorescent chromophore, anthracene, and a nitroxide radical. In the hybrid molecule, the nitroxide quenches the fluorescence of anthracene strongly. The reaction of hydroxyl radicals with dimethyl sulfoxide generates quantitatively methyl radicals, which then...

We have developed a new disinfection system for oral hygiene, proving that hydroxyl radicals generated by the photolysis of 1 M hydrogen peroxide could effectively kill oral pathogenic microorganisms. Prior to any clinical testing, the safety of the system especially in terms of the risk of carcinogenicity is examined by reviewing the literature. Previous studies have investigated indirectly th...

Our study explores the antioxidant and cytoprotective effects of baicalein and further discusses the possible mechanisms. A methyl thiazolyl tetrazolium (MTT) assay revealed that baicalein could considerably enhance the viability of hydroxyl radical-treated bone marrow-mesenchymal stem cells (bmMSCs) at 37-370 µM. The highest viability rate was 120.4%. In subsequent studies, baicalein was obser...