Synthesis,properties and photopolymerization of liquid crystalline dioxetanes

The synthesis and photopolymerization of various liquid crystalline dioxetanes is described. The effects of the spacer length, structure of the mesogenic group and oxetane group on the liquid crystalline properties, polymerization behaviour and optical properties (birefringence) of the oriented and crosslinked network formed in photo-polymerization are discussed. Thermally stable films with birefringence values up to 0.13 can be formed from these materials. The dioxetanes show significantly lower polymerization shrinkage than do structurally related diacrylates.     

Estimation of population spectrum for linear processes with random coefficients

A set of time series generated by stationary linear processes with an absolutely continuous spectral distribution is analysed. The time series can then be considered realizations of a linear process of random coefficients. Likewise, each spectral density function is a realization of a stochastic process whose function of means is called a population spectrum. We propose a kernel estimator for the population spectrum and give conditions for its consistency. We then illustrate the properties of this estimator in a simulation study and compare its performance with an alternative parametric estimator that can be found in the literature.      

Germs of holomorphic vector fields in C3 without a separatrix

Oblatum 28-XII-1988 & 26-III-1990 & 10-X-1990 & 13-VI-1991 & 30-IX-1991     

Wetting and electrical properties of the human hair surface: delipidation observed at the nanoscale

The electrostatic properties and the wetting behaviour of the human hair surface at the nanometric scale have been investigated by using atomic force microscopy (AFM). Surface potential imaging was used to determine the electrostatic properties while non-contact mode AFM was used to investigate the wetting properties of a test liquid, squalane. We have studied natural hair and hair in which different covalently (18-methyleicosanoic acid) and non-covalently bound fatty acids present at the cuticle surface were selectively extracted. This study shows how the removal of these acids causes various profound changes in hair wettability at the cuticle scale.     

Critical Analysis of Hypothesis Tests in Federal Information Processing Standard (140-2)

This work presents an analysis of the existing dependencies between the tests of the FIPS 140-2 battery. Two main analytical approaches are utilized, the first being a study of correlations through the Pearson’s correlation coefficient that detects linear dependencies, and the second one being a novel application of the mutual information measure that allows detecting possible non-linear relationships. In order to carry out this study, the FIPS 140-2 battery is reimplemented to allow the user to obtain p-values and statistics that are essential for more rigorous end-user analysis of random number generators (RNG).     

In vitro PHOTODYNAMIC ACTIVITY OF KRYPTOCYANINE

The photophysical properties of 1,1'-diethyl-4,4'-carbocyanine chloride (kryptocyanine) have been measured in methanol solution and for the dye bound to human serum albumin, incorporated in neutral micelles and after incubation with leukemia cells. In all cases, it is found that formation of the triplet state of the dye occurs with low efficiency and that illumination of the dye under aerobic conditions does not produce significant yields of O2(1 delta g). Instead, the only efficient photoprocess involves rapid internal conversion from the first excited singlet state to the ground state, probably via isomerization of the polymethine sequence. These findings are discussed with respect to the demonstrated ability of kryptocyanine to photodestroy leukemic cells.     

An efficient synthesis of 3-substituted 3H-pyrimidin-4-ones

[reaction: see text] A novel and practical synthesis of 3-substituted 3H-pyrimidin-4-ones is described. The key step involves the cyclization of enamide esters, derived from readily available beta-keto esters, with trimethylaluminum and various primary amines.