EFFECT OF TRANSMEMBRANE POTENTIAL ON CHARGE PHOTOSEPARATION IN LIPOSOMES

Abstract— An unexpected transmembrane potential effect on the recombination rate of the pheophytin or bacteriopheophytin anion-radicals (dissolved in membrane) and ascorbic ion-radicals (dissolved in aqueous interior) has been established in liposomes. The influence of transmembrane potential on the recombination rate of Ru³⁺ (dissolved in inner volume) and (C₁₈H₃₇)V⁺ or (C₁₄H₂₉)V⁺ (dissolved in membrane) was observed. The potential was created by a potassium concentration gradient between inner and outer volumes of liposomes in the presence of valinomycin. The effect of the potential was considered on the bases of: (1) it was determined by the diffusional drift of the hydrophobic radicals in a radial direction in the membrane, according to the direction of the electric field; (2) the electric field changed the rate constant of the electron transfer, owing to the effects on the free energy and electronic coupling. Our results show the first explanation to be preferable.     

X-Ray Structure and Proton NMR Study of a Hexacoordinated Lithium Complex

The structure of the lithium complex with1,3,5-tris[oxymethylene(N,N-dicyclohexyl)carboxyamido]cyclohexanehas been determined by the X-ray method.The compound is triclinic, space group P¯1,a = 15.623(3), b = 19.279(4),c = 19.295(4)Å = 102.32(3), = 92.45(3), = 105.67(3)0, V = 5436(2)Å3, Z = 4. Itscomposition is represented by the formulaC48H82N3O6LiI 0.5H2O. The lithium cationis encapsulated in a polar pseudo-cavity of six oxygen atoms of the ligandmolecule and displays a distorted trigonal prism coordination. The conformationof the ligand in the solid state complex has been compared with the conformationof the complex in solution determined by 1H-NMR measurements.Supplementary data relevant to this publication have been deposited with the British Library, No. SUP 82224 (21 pages).     

A Global Optimization Algorithm for Multivariate Functions with Lipschitzian First Derivatives

In this paper we propose a new multi-dimensional methodto solve unconstrained global optimization problems with Lipschitzianfirst derivatives. The method is based on apartition scheme that subdivides the search domain into a set of hypercubesin the course of optimization. This partitioning is regulated by thedecision rule that provides evaluation of the "importance"of each generated hypercube and selection of some partition element to performthe next iteration. Sufficient conditions of global convergence for the newmethod are investigated. Results of numerical experiments are alsopresented.     

REPRESENTATIONS OF AFFINE SUPERALGEBRAS AND MOCK THETA FUNCTIONS

We show that the normalized supercharacters of principal admissible modules over the affine Lie superalgebra $ {{\widehat{{s\ell}}}_{2|1 }} $ (resp. $ {{\widehat{{ps\ell}}}_{2|2 }} $ ) can be modified, using Zwegers’ real analytic corrections, to form a modular (resp. S-) invariant family of functions. Applying the quantum Hamiltonian reduction, this leads to a new family of positive energy modules over the N?=?2 (resp.N?=?4) superconformal algebras with central charge 3(1???(2?m?+?2)/M), where m ∈ ?_≥0, M ∈ ?_≥2, gcd(2?m?+?2, M)?=?1 if m?>?0 (resp. 6 (m/M???1), where m ∈ ?_≥1, M ∈ ?_≥2, gcd(2?m, M)?=?1 if m?>?1), whose modified characters and supercharacters form a modular invariant family.     

Optimizing a model for multiproduct batch sizes with in-process inventories and multiple work centres

This paper deals with a model for multiproduct optimal batchsizes with in-process inventories and multiple work centresformulated by Bertrand (1985). Using well-known results fromLangrange duality, it is shown that the problem can be decomposedinto a series of one-variable optimization problems. Two algorithmsare suggested.     

The forgotten liquid crystals of Daniel Vorlander: A new look at mesogenic 4-pyridones

Three classes of 4-pyridone (1H-pyridin-4-one) terminated liquid crystals were synthesized and their mesogenic properties examined. These liquid crystal classes differ in the composition of the aromatic core group which vary among azobenzene, stilbene or tolane groups. The synthesis of the 4-pyridones was accomplished by aromatic nucleophilic substitution reaction of the appropriate activated aryl fluoride with 4-hydroxypyridine. These pyridone liquid crystals possess broad enantiotropic nematic and smectic A phases and may possess useful properties such as high birefringence and polarity including hydrogen bonding capability. The original report of a 4-pyridone containing liquid crystal due to Vorlander has been substantiated.     

NUCLEATION ENHANCEMENT OF DIAMOND FILMS BY ION BOMBARDING AND ELECTRON EMITTING EFFECTS

Applying a proper negative bias-voltage onto the substrate, on which diamond lilm is deposited by chemical vapor deposition technique, can greatly improve the nucleation density. While nucle-ation enhancing, both the ion bombardment and electron emission may play an important role sepa-rately. However, for the highest nucleation density, both of the two effects must act together.     

Electro-optical properties of 4,4-bis-[omega-(4-cyanobiphenyl-4yloxy)alkyloxy]biphenyls nematics

Electro-optical properties of nematics of the trimer series 4,4-bis-[omega-(4-cyanobiphenyl-4yloxy)alkyloxy]biphenyls have been investigated by the method of orientational elastic deformations in electric fields. The number n of CH2 groups in the oxyalkyl fragment was varied from n 2 to n 10. A strong odd-even effect was observed in the optical anisotropy Deltan and in the values of the threshold potential V0 for the trimer nematics. These effects are, respectively, caused by oscillations of the degree of inter- and intra-molecular orientational order when n is varied. The great difference in the dependences of Deltan and V0 on n is discussed and compared with data for dimers.     

Valence bond analysis of the bonding in transition metal compounds: the RuNO group in nitrosyl complexes

The ab initio and semi-empirical configuration interaction wave functions of ruthenium complexes [RuL₅(XY) ^q (L &; = NH₃, Cl^?, CN^?, XY &;= N₂, CO) are presented in the form of linear combinations of the valence bond (VB) structures, each structure being referred to some covalent or ionic model of the bonding in the M-XY group. The results of this VB analysis showed that [RuL₅(NO)] ^q complexes can be described as compounds of Ru(III) and neutral NO⁰ with a covalent π-bond in addition to the usual coordination bond.     

Three-body interaction-induced light scattering in krypton gas: a computer simulation of the spectral line shapes

The two-, three- and four-body effective collision induced scattering spectral line shapes are calculated for dense gaseous krypton using the pairwise additivity (PA) approximation and different polarizability models. These spectra and several interaction induced spectra calculated at various densities are compared with the experimental measurements of Barocchi et al. [1988, Europhys. Lett., 5, 607]. The potential effect on the spectrum is found to be weak. The results obtained with the Meinander et al. [1986, J. chem. Phys., 84, 3005] empirical polarizability model and molecular dynamics fit well the experimental two- and three-body spectral shapes. The irreducible contribution to the spectral shape is evaluated using the dipole induced dipole irreducible polarizability [buckingham, A. D., and Hands, I. D., 1991, Chem. Phys. Lett., 185, 544]. This contribution is found to be relatively weak for the anisotropic spectra in the frequency and density range studied, explaining the good agreement between the pairwise approximation calculations and the experimental data. The spectra radiated by the quasi-molecules Kr₂, Kr₃, and Kr₄ (the total spectrum within the PA approximation) are also simulated.