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Badania strukturalne cyklicznych β-aminoketonów z wykorzystaniem metod obliczeniowych i analizy NMR

Sidorowicz K., Łaźny R.

Chemik

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2015

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Vol. 69, nr 7

401--410

PL

Przestrzenna konfiguracja na atomie azotu w cyklicznych β-aminoketonach powoduje, że związki te mogą występować w dwóch stereoizomerycznych formach, w których podstawniki na tym atomie mogą przyjmować orientację aksjalną lub ekwatorialną w stosunku do pierścienia piperydonu. Stereochemia N-podstawionych bicyklicznych β-aminoketonów była badana za pomocą metod eksperymentalnych i teoretycznych, m.in.: spektroskopia NMR, spektroskopii mikrofalowa, rentgenografii strukturalnej i obliczeń DFT.

EN

Because of pyramidal configuration of the nitrogen atom, tropanes, granatanes, and their derivatives can exist in two stereoisomeric forms, in which N-substituents can be oriented axial or equatorial with respect to the piperidone ring. The N-invertomer stereochemistry of N-substituted bicyclic β-amino ketones has been investigated using experimental, and theoretical methods, such as NMR, microwave spectroscopy, crystallography, and DFT calculations.

2

The investigation of ∑(ri)² of liquid crystal molecule of homoloque CBn (5-9)

Adamski P.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 5

45-47

EN

The temperature dependence of the polarizability tensor components α || 1, α⊥ 1 and new quantity ∑(ri)² were investigated for homologue of CBn liquid crystals, For ache liquid crystal the new quantity ∑(ri)² was found for two temperature like the transition temperature to the solid state Tc and the transition temperature to the liquid TO. Both functions ∑(ri)²TC and ∑(ri)²TO are linear function of molecular weight but inclination of these functions are different. The cutting of these line gives us the values of molecular weight limited the range of existing of liquid crystals properties.

PL

Badano temperaturowe zależności składowych tensora polaryzowalności cząsteczki α| |1, α⊥ 1 oraz nową wielkość ∑(ri)² homologu ciekłych kryształów CBn. Dla każdego ciekłego kryształu znaleziono wartości ∑(ri)² (suma kwantów odległości elektron proton w atomach cząsteczki) dla dwóch temperatur przejścia ciekłego kryształu do stanu ciała stałego ∑(ri)²TC oraz do ∑(ri)²TO. Obie funkcje masy ciekłych kryształów są liniowe i mają różne współczynniki nachylenia. Przecięcie tych linii daje ograniczenie występowania ciekłych kryształów.

3

Allosteric systems on biological membrane analysis by time minimum optimal control principle

Hirayama H., Okita Y.

Systems Science

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2000

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Vol. 26, nr 4

121-145

EN

We calculated temporal changes in concentrations of species in biological allosteric system. The allosteric nature was described by co-operativity and concerted actions of identical subunits composing the system. The co-operativity was characterized by accelerated bindings of substrates to the subunits and their structural changes. The concerted mechanism provokes all or non-conformational change of an entire molecule from its inactive to active sate at one time. As the number of bound substrate increases, the concerted conformational transition of all the subunits strongly directs to active state. These two properties save the time to complete activation of the system and full substrate binding. The allosteric actions are frequently observed in the critical emergency conditions such as oxygen binding, immune defense reaction and ionic channel gating on excitable membrane of the bio-signal transmission. Hence, the temporal actions of allosteric systems can be interpreted as the shortest time controlled system. We thus, proposed the time minimum optimal control principle as an organizing strategy for activating and binding processes of the allosteric systems. We presented fifteen non-linear differential equations for describing the temporal changes in concentrations of the species composing a two activators-two substrates allosteric system. Another set of fifteen non-linear differential equations for co-state variables were obtained by partial differentiation of the Hamiltonian of the system based on the minimum optimal control theory. The computed temporal concentrations of species oscillated. A reduction of an allosteric parameter shifted these temporal changes synchronously. When the amounts of substrate and activator were set as time invariant, the oscillations disappeared and the concentration of the species approached a steady level. These computed results are qualitatively consistent with actual biophysical phenomena. The present mathematical description of transient changes in concentrations of species in biological allosteric system will be available for evaluating the effective and economical performance of the allosteric system acting under the critical emergency circumstances.