The germicidal potency of quatemary ammonium compounds is known to depend mainly on the chemical structure of the cation, the nature of the anion having little if any effect (Glassman, 1948). The relation of structure of the cation to bactericidal activity has been studied extensively insofar as chain length of the hydrophobic or hydrocarbon group is concerned. In compounds with only one long c...

This review summarizes our recent findings on the role of mineral salts in prebiotic RNA synthesis, which is catalyzed by montmorillonite clay minerals. The clay minerals not only catalyze the synthesis of RNA but also facilitate homochiral selection. Preliminary data of these findings have been presented at the "Horizontal Gene Transfer and the Last Universal Common Ancestor (LUCA)" conference...

Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibr...

OBJECTIVE The main objective of this study was to investigate thermosensitive Pluronic F-127 (PF-127) hydrogel for the modified release of a potent alcohol and opioid antagonist, naltrexone (NTX) hydrochloride, in a subcutaneous injectable dosage form. METHODS The NTX hydrogels were prepared by the cold method, and the in vitro release profiles of various formulations were evaluated at 37°C u...

The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aero...

To predict bile salt-membrane interactions physiologically, we used an immobilized artificial membrane HPLC column that contains dimyristoyl-phosphatidylcholine molecules covalently linked to silica microspheres. Using a 90% aqueous (10% acetonitrile) mobile phase, 22 species of bile salts and 4 species of fusidates were eluted. Glycine conjugates displayed higher affinity for the column at pH ...

Tri-block copolymers (poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), represented as EOxPOyEOx), pluronics (F127 = EO106PO70EO106, P65 = EO20PO30EO20, P85 = EO27PO39EO27, P103 = EO17PO55EO17, and P123 = EO20PO70EO20) and cationic surfactants (cethyltrimethylammonium bromide (CTAB)), two surfactant systems, form complex micelles that self-assemble into mesostructured particles w...

Highly efficient and selective chemical reactions are desired. For small molecule chemistry, the reaction rate can be varied by changing the concentration, temperature, and solvent used. In contrast for large biomolecules, the reaction rate is difficult to modify by adjusting these variables because stringent biocompatible reaction conditions are required. Here we show that adding salts can cha...

This article describes a method for patterning certain solids—insoluble salts and reduced metals—in sheets of paper. Chemical reactions that produce these solids as precipitates occur when a stamp of patterned paper inked with an aqueous solution of reagent comes into contact with a paper substrate containing a second reagent. The pattern is determined by a hydrophobic barrier on the stamp that...

In 3D domain swapping, a domain of a protein breaks its noncovalent bonds with the protein core and its place is taken by the identical domain of another molecule, creating a strongly bound dimer or higher order oligomer. For some proteins, including diphtheria toxin, 3D domain swapping may affect protein function. To explore the molecular basis of 3D domain swapping in a well-characterized pro...