摘要:

DNA fragments can be immobilized by Langmuir - Blodgett films of 1-hexadecylamine. The inclusion in these LB films of 5′-GTAAAACGACGGCCAGT-3′ was proved by a radioactive technique. An X-ray diffraction study proved an overall lamellar ordering of the samples and suggested a structural organization in which layers of oligonucleotide molecules are sandwiched between two monolayers of 1-hexadecylamine. These monolayers are likely to turn their amino groups surfaces to the oligonucleotide molecules as to screen their anionic charges.

ISSN:1058-725X    

DOI:10.1080/10587259208038527

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Langmuir films of the lipids dipalmitoylphosphatidylcholine, docosanoic acid and octadecanol, in presence of two antibiotic ionophores, monensin sodium salt and lasalocid sodium salt have been studied. An important area increase as a consequence of antibiotic addition has been observed in the π-A isotherms of the phospholipid. The effect has been considered as a result of ionic cavity formation accompanied by rearrangements in the lipid hydrocarbon chains. A smaller area increase of monolayers from the single chain lipids has been observed only when monensin sodium salt was added. Monolayer studies of monensin sodium salt allowed molecular area estimations of the pure antibiotic in the film.

ISSN:1058-725X    

DOI:10.1080/10587259208038528

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Some electric properties of some fatty acids(arachidic, arachidonic, elaidic and lauric) and fatty acid-cholesterol mixtures were determined. The I = I(U) plots revealed a hysteresis behaviour, the hysteresis area being dependent on the choleaterol content. From the I = I(t) plots, the relaxation time τ and the space charge Qspwere determined and it was shown that in case of arachidic acid-cholesterol mixtures 1+1 molar, τ and Qspreached maxima. The results are explained by considering a hopping mechanism for conduction.

ISSN:1058-725X    

DOI:10.1080/10587259208038529

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The flexoelectric response of the oscillating membrane for different frequencies is studied. The influence of the adsorption of ions of different valencies on the membrane flexoeffect is considered. Different adsorption mechanisms corresponding to different binding of the electrolyte counterions to the lipid molecules are proposed.

ISSN:1058-725X    

DOI:10.1080/10587259208038530

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Surface pressure - mean molecular area isotherm is measured for a monolayer from dimyristoil-nitrobenzoxadiazol-phosphatidylethanolamine at the air-water interface. The observed very rich polymorphism is discussed.

ISSN:1058-725X    

DOI:10.1080/10587259208038531

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A simple method of dispersing nematics in poly (vinyl alcohol) and other polymers is presented. This method may be used for fundamental studies of different dispersed nematic materials.

ISSN:1058-725X    

DOI:10.1080/10587259208038532

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The electro-optic response in the C* phase of a side-chain polyacrylate and its monomer has been found to exhibit an anomalous dependence on temperature. The apparent tilt angle undergoes a sign reversal. The anomaly is attributed to a sign reversal of the spontaneous polarization, caused by molecular conformational changes in the monomer part.

ISSN:1058-725X    

DOI:10.1080/10587259208038533

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The temperature dependence of the HTP of 1, 4-bis-(S-1-(1-naphthyl)ethylamion)-9, 10-anthraquinone [S-5] or [R-5] and of 1, 8-bis-(S-1-(1-naphthyl)ethylamion)-9, 10-anthraquinone [S-6in ZLI 1695 (Merck) is expounded to be a consequence of a shift of an equilibrium between at least two conformers A ⇄ B with an equilibrium constant K < 1, derived from the temperature dependence of a CD couplet. Conditional on this equilibrium, the HTP(T) is a linear function of the amplitude of the couplet. The sign of the CD of the isotropic solution is determined by the conformer A whereas the sign of the HTP is given by B. The helix inversion for [S-5] in ZLI 1132 (Merck) appears to be a result of a slightly increasing concentration of the conformer B.

ISSN:1058-725X    

DOI:10.1080/10587259208038534

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A thermal and X-ray investigation is reported of a main-chain polyester consisting of two p-oxybenzoate diads alternatively spaced by a pentamethylene and an heptamethylene segment. Evidences are provided for the existence of an enantiotropic smectic C phase and a monotropic nematic phase. Cooling from the mesophase allows for the lock-in of the smectic C structure in the glassy state.

ISSN:1058-725X    

DOI:10.1080/10587259208038535

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

To look into the nature of intermolecular forces responsible for the induced smectic mesophase formation, model binary systems were studied comprising components of different chemical classes. Three distinct types of systems could be singled out, with translational order enhancement presumably due to (a) steric factors, (b) dipole-dipole in eractions, and (c) change-transfer complex formation.

ISSN:1058-725X    

DOI:10.1080/10587259208038536

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor