Synaptic transmission as a cooperative phenomenon in confined systems

In this review paper, the theory of synaptic transmission (ST) was developed and discussed. We used the hypothesis of isomorphism between: (a) the cooperative behavior of mediators --- acetylcholine molecules (ACh) and cholinoreceptors in a synaptic cleft with binding into mediator-receptor (AChR) complexes, (b) the critical phenomena in confined binary liquid mixtures. The systems of two (or three) nonlinear differential equations were proposed to find the change of concentrations of ACh, AChR complexes, and ferment acetylcholinesterase. The main findings of our study: the linear size of the activation zone was evaluated; the process of postsynaptic membrane activation was described as a cooperative process; different approximations of ACh synchronous release were examined; stationary states and types of singular points were studied for the proposed models of ST; the nonlinear kinetic model with three order parameters demonstrated a strange-attractor behavior.Comment: 12 pages, 1 figur

Optimum pulse shapes for stimulated Raman adiabatic passage

Stimulated Raman adiabatic passage (STIRAP), driven with pulses of optimum shape and delay has the potential of reaching fidelities high enough to make it suitable for fault-tolerant quantum information processing. The optimum pulse shapes are obtained upon reduction of STIRAP to effective two-state systems. We use the Dykhne-Davis-Pechukas (DDP) method to minimize nonadiabatic transitions and to maximize the fidelity of STIRAP. This results in a particular relation between the pulse shapes of the two fields driving the Raman process. The DDP-optimized version of STIRAP maintains its robustness against variations in the pulse intensities and durations, the single-photon detuning and possible losses from the intermediate state.Comment: 8 pages, 6 figures. submitted to Phys. Rev.

Molecular genetic and clinical aspects of socially relevant viruses underlying congenital diseases

Congenital viral infectious diseases are characterized by polyetiologic pathology holding an important place in the structure of perinatal losses. Due to the wide distribution and lack of specific prophylaxis, the problem of herpesvirus infections is of greatest interest, namely of herpes infection caused by herpes simplex virus type 1 and 2, human herpes simplex virus type 6 and cytomegalovirus infection, as well as parvovirus infection B19. The opportunities to investigate a relation between manifestations of the infectious process and host molecular genetic characteristics have been expanded after developing full genome sequencing methods and creating genetic data international banks. It has been proven that herpes virus genetic variations can account for related neurovirulence, showing that diverse cytomegalovirus genotypes are associated with hepatosplenomegaly, hearing impairment and the symptoms of the central nervous system diseases. Nevertheless, the data on correlation between genotypes and clinical manifestations are still scarce and contradictory, whereas high level of variability becomes extremely evident while comparing genomic sequences of viral strains. The herpesvirus type 6 has been proven to integrate into germ cells with potential for subsequent vertical transmission of chromosomally integrated virus to the offspring and its further intergeneration inheritance. А direct relationship between B19V genospecies and disease manifestations including congenital infections has not yet been identified. Taking into account possible differences in the geographical distribution of such viruses on the territory of the Russian Federation, ethnic populational characteristics, and high frequency of related congenital infectious diseases with a wide range of clinical manifestations, it seems promising to expand scientific research on the genotyping of herpes simplex viruses, cytomegalovirus, herpes viruses type 6 and parvovirus B19V in Russia. The results of such studies will be demanded by practical healthcare in order to develop and use more effective etiotropic drugs and specific prophylaxis in the light of trends to develop personalized and preventive medicine