An investigation of the reliability of the Galerkin-Petrov method

The Galerkin-Petrov method is applied to the determination of the ground state energy of the beryllium atom. The basis set of the coordinate subspace consists of correlated wavefunctions of the combined configuration-interaction-Hylleraas type. The basis set of the projective subspace is of the configuration-interaction type. The usefulness of a previously proposed way of characterization of pairs of subspaces has been further confirmed. Experience in constructing close pairs of subspaces gathered in the case of two-electron systems is used for the larger system. Two methods for constructing pairs of subspaces are used in the calculations.     

Free-flow isoelectric focusing of proteins remaining in cell fragments following sonication of thyroid carcinoma cells

The method of preparing protein mixtures for electrophoretic analysis of membrane-associated cell proteins was improved. By sonication, about one-half of the proteins of thyroid cells were released into the supernatant, while the other half preferentially comprising membrane proteins still remained in cell fragments, which could be sedimented by centrifugation. After sonication, even those proteins which remained in cell fragments, could completely be dissolved by free-flow isoelectric focusing media. They migrated through the free-flow electrophoresis chamber without forming precipitates. Because of these improvements, it was possible to show that the two thyroid cancer cell lines ML-1 and ONCO-DG1 express cytokeratin 8 at similar rates, but cytokeratins 7 and 18 differently. In addition, the presence of inorganic pyrophosphatase, tubulin-beta-5, and tubulin-beta-1 chains in human thyroid cells was proved for the first time.     

Studies towards the total synthesis of di- and sesterterpenes with dicyclopenta[a,d]cyclooctane skeletons. Three-component approach to the A/B rings building block

Sesqui- and sesterterpenes of ophiobolin and fusicoccin families are important synthetic targets because of complexity of structure and potentially useful physiological activities, including anti-tumor activity. A synthesis of versatile building blocks for these terpenoids is described. Cyclopenta[8]annulene rings system with properly dislocated substituents was constructed using as key steps ring closing metathesis reaction and Wagner - Meerwein rearrangement. Ring closing metathesis reaction leading to cyclopenta[8]annulene was studied in detail.     

Semi-empirical calculations of dihydropyran conformations

Semi-empirical calculations of dihydropyran conformations have been performed using a Karplus-type equation with the sum of chemical shifts as a correction parameter. A graphical method has been proposed to evaluate the conformational state of the molecules.     

A complex impedance study of Pt∣NaCl and C∣NaCl interfaces

The a.c. impedance of Pt∣NaCl∣Pt and C∣NaCl∣C cells was measured in the frequency range from 10^?3 to 10³ Hz. Two contributions to the interface impedance could be distinguished, hindered charge transfer and an adsorption/desorption or slow reaction contribution, the latter being the rate determining step in the frequency range studied. An approximately symmetric nonlinear dependence of both the capacitance and the conductance on overvoltage was found at the lowest frequencies, indicating that the crystal/electrode interface is in a state which can be characterized as close to equilibrium. It should be ensured by two electrochemical reactions of approximately equal rates. The concept of a temporarily reversible electrode is introduced. It is a result of the ability of ions to discharge at the interface and to produce a finite reservoir of adsorbed or absorbed reaction products. An external voltage increases or reduces this reservoir, and therefore only a transient electric current may be carried by a backward reaction.     

Quantum key distribution based on arbitrarily weak distillable entangled states

States with private correlations but little or no distillable entanglement were recently reported. Here, we consider the secure distribution of such states, i.e., the situation when an adversary gives two parties such states and they have to verify privacy. We present a protocol which enables the parties to extract from such untrusted states an arbitrarily long and secure key, even though the amount of distillable entanglement of the untrusted states can be arbitrarily small.     

A simple and practical phase-separation approach to the recycling of a homogeneous metathesis catalyst

The air stable asarone-derived Ru carbene 16, a robust olefin metathesis catalyst, can be easily separated after reaction by deposition on silica gel and reused up to nine times. This procedure provides products of excellent purity with low Ru content.     

Multiple Solutions of Boundary-Value Problems for Fourth-Order Differential Equations with Deviating Arguments

This paper considers fourth-order differential equations with four-point boundary conditions and deviating arguments. We establish sufficient conditions under which such boundary-value problems have positive solutions. We discuss such problems in the cases when the deviating arguments are delayed or advanced. In order to obtain the existence of at least three positive solutions, we use a fixed-point theorem due to Avery and Peterson. To the authors’ knowledge, this is a first paper where the existence of positive solutions of boundary-value problems for fourth-order differential equations with deviating arguments is discussed.     

Correlation of F0F1-ATPase inhibition and antiproliferative activity of apoptolidin analogues

[structure: see text] Apoptolidin (1) exhibits potent and highly selective apoptosis inducing activity against sensitive cancer cell lines and is hypothesized to act by inhibition of mitochondrial F(0)F(1)-ATP synthase. A series of apoptolidin derivatives, including a new intermolecular Diels-Alder adduct, were analyzed for antiproliferative activity in E1A-transformed rat fibroblasts. Potent F(0)F(1)-ATPase inhibition was not a sufficient determinant of antiproliferative activity for several analogues, suggesting the existence of a secondary biological target or more complex mode of action for apoptolidin.