Methylobacterium species are representative of methylotrophic bacteria. Their genomes usually encode two types of methanol dehydrogenases (MDHs): MxaF and XoxF. The former is a Ca2+-dependent enzyme, and the latter was recently determined to be a lanthanide-dependent enzyme that is necessary for the expression of mxaF. This finding revealed the unexpected and important roles of lanthanides in b...

2,6-di(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (n-Pr-BTP), first developed in our laboratory, is a very promising extractant for the effective separation of actinides(III) from lanthanides(III). It is able to extract actinides(III) with usable distribution coefficient from 1-2 molar nitric acid selectively over lanthanides(III). The Am(III)/Eu(III) separation factor is approx. 135. The perform...

Definitions and characteristics The rare earth elements (REE) (sometimes referred to as the rare earth metals) are a group of 17 chemically similar metallic elements, including the 15 lanthanides, scandium and yttrium. The lanthanides are elements spanning atomic numbers 57 (lanthanum, La) to 71 (lutetium, Lu) (Table 1). The lanthanides all occur in nature, although promethium, the rarest, only...

Lanthanides possess similar chemical properties rendering their separation from one another a challenge of fundamental chemical and global importance given their incorporation into many advanced technologies. New separation strategies combining green chemistry with low cost and high efficiency remain highly desirable. We demonstrate that the subtle bonding differences among trivalent lanthanide...

Actinides, the last known group of the Periodic Table are the subject of a special interest, both practical and scientific. Though their use is mainly based on their unique nuclear properties, the electronic structure is of no little interest because it is of paramount importance in determining the physical and chemical properties of the actinides and their compounds. Despite the common tendenc...

An HPLC method is presented for the separation and determination of lanthanides (Lns), thorium (Th), uranium (U) and plutonium (Pu) from irradiated (Th, Pu)O2. Individual separation of Lns, Th, U and Pu is a challenging task because of 1) lanthanides having similar physical and chemical properties, 2) presence of complex matrix like irradiated fuel and 3) the co-existence of multiple oxidation ...

The interactions of calcium and lathanides with the sarcoplasmic reticulum ATPase, and their respective ability to activate the enzyme, were studied by direct measurements of binding with radioactive tracers, functional effects on the ATPase partial reactions, changes in the quantum yield of tryptophanyl residues and a covalently bound fluorescein label (fluorescein 5-isothiocyanate, FITC), and...

Lanthanum was previously reported to potentiate the GABA-induced chloride currents reversibly by acting at a distinct site on the GABAA receptor-channel complex (Ma and Narahashi, 1993). We now report that all other lanthanides tested enhanced the GABA responses with greater efficiencies and produced inward currents by themselves. The rank order of efficacies of lanthanides to potentiate the GA...

in recent years, using sol-gel procedure for the purpose of laboratory and industrial synthesis of nano-structures, and especially silica nano-particles, has been significantly increased. in this research, silica particles were synthesized by sol-gel procedure and their physical and chemical properties were studied by means of scanning electron microscopy (sem), transmission electron microscopy...