An extended model for chirality selection in single-walled carbon nanotubes.

The chirality selective production of single-walled carbon nanotubes (SWCNTs) continues to represent one of the most important technological challenges. In this study, an extended model which considers all steps of the SWCNT growth process, including adsorption, decomposition, diffusion, and incorporation, is applied, for the first time, to obtain chirality selection in the SWCNT populations. We show that the dependence of the population distribution on chirality, defined as a product of the nucleation probability and the growth rate, has a volcano-shape.

Non-poissonian Distribution of Point Mutations in DNA.

In general, for chemical reactions occurring in systems, where fluctuations are not negligibly small, it is necessary to introduce a master equation for distribution of probability of fluctuations. It has been established that the monomolecular reactions of a type as ↔ are described by the master equation, which leads to a Poisson distribution with the variance equal to the average value . However, the consideration of the Löwdin mechanism as autocatalytic non-linear chemical reactions such as + ↔ 2 and the corresponding master equation lead to a non-Poissonian probability distribution of fluctuations.

[Thermoadsorptive separation of DNA by size using a polymeric sorbent].

The article describes theoretical aspects of isolation and separation of DNA fragments by size using a polymeric sorbent. On this basis we presented a theoretical model of thermal desorption of DNA fragments of different length. Assuming that, under certain pH, interaction of DNA with the polymer sorbent is of an ion-dipole character and moving dipoles interact with the sorbent according to the Boltzmann distribution with the total charge of the DNA fragment in its pore, the expression for the interaction energy as a function of temperature is obtained.

[Tactics of measles epidemiologic surveillance during elimination period].

Aim: Evaluation of effectiveness of new tactics of measles epidemiologic control in measles elimination in Russian Federation.

Materials And Methods: Analysis of active search of measles patients among patients with fever and maculopapular rash is presented. Range of primary diagnosis and rate of detection of measles cases is studied.