Sitafloxacin (STFX) hydrate, an antimicrobial agent, is photo-labile in aqueous solutions. The photodegradation rates (k) in neutral solutions were higher than those observed in acidic and alkaline solutions and maximum at the maximum absorption wavelength of STFX. The structures of photodegradation products were elucidated as 7-[7-amino-5-azaspiro[2.4]heptan-5-yl]-6-fluoro-1,4-dihydro-4-oxo-3-...

The chloride ion, Cl(-), is an essential cofactor for oxygen evolution of photosystem II (PSII) and is closely associated with the Mn(4)Ca cluster. Its detailed location and function have not been identified, however. We substituted Cl(-) with a bromide ion (Br(-)) or an iodide ion (I(-)) in PSII and analyzed the crystal structures of PSII with Br(-) and I(-) substitutions. Substitution of Cl(-...

The redetermined, low temperature (150 K), structure of tetra-n-butyl-ammonium bromide, (C(4)H(9))(4)N(+)·Br(-), has been found to be merohedrally twinned via twin law -1 0 0, 0 - 1 0, 1 0 1. The structure was previously determined, with low precision, no inclusion of H atoms and only the bromide ion refined with anisotropic displacement parameters, by Wang et al. (1995 ▶). Mol. Cryst. Liq. Cry...

The characteristics of dissolved organic matter (DOM) and bromide ion concentration have a significant influence on the formation of disinfection by-products (DBPs). In order to identify the main DBP precursors, DOM was divided into five fractions based on molecular weight (MW), trihalomethane formation potential and haloacetic acid formation potential were determined for fractions, and the cha...

Nerve growth factor (NGF) receptor binding in membrane fractions of rabbit superior cervical ganglia has been measured after treatment with a variety of enzymes, protein-modifying reagents, and ions. Receptor binding is degraded by low concentrations of trypsin but is much less sensitive to alpha-chymotrypsin. Low concentrations of phospholipase A from Vipera russelli decrease NGF receptor bind...

Two analytical methods, which prove the utility of a potentiometric flow injection technique for determining various redox species, based on the use of some redox potential buffers, are reviewed. The first is a potentiometric flow injection method in which a redox couple such as Fe(III)-Fe(II), Fe(CN)(6) (3-)-Fe(CN)(CN)(6) (4-), and bromide-bromine and a redox electrode or a combined platinum-b...

an ultrasound-assisted surfactant-enhanced emulsification microextra- ction (uaseme) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of thiopental in serum and urine samples. a simple microextraction method based on emulsification of organic extraction solvent in aqueous sample using an ionic surfactant and withou...

poly(styrene-co-butyl acrylate)/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. the living nature of polymerization is confrmed by occurrence of narrow molecula...

The density (d), speed of sound (u) and electrolytic conductivity (Λ) for systems containing acetaminophen, ionic liquid {1-octyl-3-methyl imidazolium bromide, [OMIm] Br} and water have been measured at T = 293.15-308.15 K. The measured data have been applied to calculate, standard partial molar volume ( ), Hepler’s constant , apparent molar isentropic compressibility...

On the basis of lithium electrolyte mechanism, modified glassy polymers were developed by adding salts to poly(methyl methacrylate) (PMMA). This review summarizes how rheological and mechanical properties PMMA changed introducing various salts: perchlorate (LiClO4), trifluoroacetate (LiCOOCF3), trifluoromethanesulfonate (LiCF3SO3), nonafluorobutanesulfonate (LiC4F9SO3), bromide (LiBr). It was f...