The production of L-tryptophan through chemical synthesis, direct fermentation, bioconversion and enzymatic conversion has been reported. However, the role of transport system for aromatic amino acids in L-tryptophan producing strains has not been fully explored. In this study, the fact was revealed that L-tryptophan production and cell growth were affected by the modification of transport syst...

Studies on the relative reactivities of esters of oncogenic and nononcogenic members of the purine N-oxide series indicate that, despite similarities in rates of reaction with the solvent, electrophilic cations from oncogenic derivatives are 10- to 100-fold more reactive toward added nucleophiles in vitro than are cations from nononcogenic compounds. The studies provide strong confirmation of a...

A significant part of the thin layers of counter-ions adjacent to the exterior and interior surfaces of a cell membrane form quasi-two-dimensional (2D) layers of mobile charge. Collective charge density oscillations, known as plasmon modes, in these 2D charged systems of counter-ions are predicted in the present paper. This is based on a calculation of the self-consistent response of this syste...

We present a short overview over recent MD simulations of systems of fully flexible polyelectrolyte chains with explicitly treated counter ions using the full Coulomb potential. The main emphasis is given on the conformational properties of the polymers, with a short discussion on counter ion condensation.

Although ion specificity in aqueous solutions is well known, its manifestation in unconventional strong electrostatic interactions remains implicit. Herein, the ionic effects in dense packing of highly charged polyelectrolytes are investigated in supramolecular nanotube prototypes. Distinctive behaviors of the orthorhombic arrays composed of supramolecular nanotubes in various aqueous solutions...

In this study, we synthesized the new kinds of semiconducting polymeric gels having negative (n-type) and positive (p-type) counter ions as charge carriers. The polyacrylamide gel was doped with pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid, trisodium salt), having SO(3)(-) ions as side groups and Na(+) as counter ions, so-called p-type semiconducting gel. The doping process was performed du...

In the title complex, [Ru(C(10)H(8)N(2))(2)(C(5)H(6)N(2))(2)](PF(6))(2)·CH(3)CN, the Ru(II) atom is bonded to two α-diimine ligands, viz. 2,2'-bipyridine, in a cis configuration and to two 4-amino-pyridine (4Apy) ligands in the expected distorted octa-hedral configuration. The compound is isostructural with [Ru(C(10)H(8)N(2))(2)(C(5)H(6)N(2))(2)](ClO(4))(2)·CH(3)CN [Duan et al. (1999 ▶). J. Coo...