Biomedical subjects

V I Tarasov

Publications and source records attributed to V I Tarasov.

At least 19 recordsLinked to original sources

PubMed2006

Quantum mechanical polarizable force field (QMPFF3): refinement and validation of the dispersion interaction for aromatic carbon.

The authors have recently introduced a general, polarizable force field QMPFF fitted solely to high-level quantum mechanical data for simulations of biomolecular systems. Here the authors demonstrate using an advanced version QMPFF3 how the problem of insufficient accuracy of the MP2-based training set for the aromatic carbon atom type can be effectively solved by a simple model correction using state-of-the-art CCSD(T) data. The approach demonstrates excellent transferability, which is confirmed for three phases of matter by accurate calculations of the second virial coefficient for benzene vapor and various properties of liquid benzene and polyaromatic hydrocarbon crystals.

Journal Article↗

PubMed2006

Water properties from first principles: simulations by a general-purpose quantum mechanical polarizable force field.

We have recently introduced a quantum mechanical polarizable force field (QMPFF) fitted solely to high-level quantum mechanical data for simulations of biomolecular systems. Here, we present an improved form of the force field, QMPFF2, and apply it to simulations of liquid water. The results of the simulations show excellent agreement with a variety of experimental thermodynamic and structural data, as good or better than that provided by specialized water potentials. In particular, QMPFF2 is the only ab initio force field to accurately reproduce the anomalous temperature dependence of water density to our knowledge. The ability of the same force field to successfully simulate the properties of both organic molecules and water suggests it will be useful for simulations of proteins and protein-ligand interactions in the aqueous environment.

Diffusion↗

PubMed2005

A quantum mechanical polarizable force field for biomolecular interactions.

We introduce a quantum mechanical polarizable force field (QMPFF) fitted solely to QM data at the MP2/aTZ(-hp) level. Atomic charge density is modeled by point-charge nuclei and floating exponentially shaped electron clouds. The functional form of interaction energy parallels quantum mechanics by including electrostatic, exchange, induction, and dispersion terms. Separate fitting of each term to the counterpart calculated from high-quality QM data ensures high transferability of QMPFF parameters to different molecular environments, as well as accurate fit to a broad range of experimental data in both gas and liquid phases. QMPFF, which is much more efficient than ab initio QM, is optimized for the accurate simulation of biomolecular systems and the design of drugs.

Journal Article↗

PubMed2001

[Dystrophin gene expression in patients with Duchenne muscular dystrophy after myoblast transplantation].

Based on originally designed technique of myoblast cultivation and in accordance with the approved by the Russian Ministry of Health "one muscle treatment" protocol of myoblast transplantation to the Duchenne muscular dystrophy patients, the first in Russia clinical trial of this gene correction method was carried out. Immonologically related myoblast cultures (30 to 90 million cells per patient) were injected after all preliminary procedures into tibialis anterior muscles of four boys selected from a group of volunteer recipients (Duchenne muscular dystrophy patients) based on the analysis of a number of surface antigens in donor-recipient pairs. The condition of the patients remained satisfactory during the whole period of post-transplantation follow-up (from 6 months to 1.5 years). Six months after myoblast transplantation the presence of donor DNA or dystrophin synthesis was demonstrated in muscle biopsies of three out of four patients. This result confirms efficacy and safety of the procedure used.

Antigens, Surface↗

PubMed1995

Reduced integral solutions for gamma absorbed dose from Gaussian plume.

Exact two-dimensional and asymptotic one-dimensional integral solutions were obtained for the external dose rate value due to a Gaussian plume. The relative error of the asymptotic solution was found to be less than 5% for downwind distances of 1 to 300 mean free path lengths and for crosswind distances of 0 to 40 mean free path lengths. A good agreement was observed with the results of plume dose rate calculations published earlier.

Air Pollutants, Radioactive↗

PubMed1994

Statistical analysis of radioactive contamination levels in settlements of the Chernobyl middle zone.

A statistical analysis of the measurements of 137Cs activity density carried out in 1990-1991 in 30 settlements of the mesozone (and partially in the nearest zone) of the Chernobyl nuclear power plant is presented. It is shown that the mean activity density of radionuclides is close to 14 Bq cm-2 for the inspected settlements of Byelorussia which is significantly less than that for the inspected settlements of the nearest zone (48 Bq cm-2). The analysis shows that there is a near linear correlation between rms deviation of activity density and its mean value. It is also shown that the correlation radius of the data is comparable with the spatial step of the measurements and that the activity density distribution is reasonably described in terms of a normal distribution.

Accidents↗

PubMed1993

A factorization procedure for calculations of gamma exposure from radioactive clouds.

A procedure is proposed to factor the integrand in the expression for dose characteristics of gamma emission of radioactive clouds. This method permits a reduction of the multiplicity of the integration for conventional models with an arbitrary collocation of a source and a receptor. This can result in more economic numerical schemes for analyzing the consequences of radioactive releases into the atmosphere.

Air Pollutants, Radioactive↗

PubMed1991

Theoretical prediction on functional domains from the primary structure of enterotoxin B and correlation with experimental data.

Theoretical analysis of the primary amino acid structure of St. aureus enterotoxin B for predicting some structure-functional characteristics is presented. The method is based on correlation between the spectrum of numerical presentation of any amino acid sequence and its biological function. This is accomplished by assigning to each amino acid a numerical value. The mathematical processing of the data is carried out with a digital robust algorithm on the basis of running media and mean filtering. The above analysis indicates that SEB contains in the polypeptide chain at least some abnormal regions whose correlation with our experimental data is shown. Three of these have a stable conformation, while the other seven domains may be formed upon an additional energy action on the molecule, which indicates the reactive ability of SEB.

Algorithms↗

PubMed1986