Publications by authors named "Oleg Kozlov"

Currently available genetic tools effectively distinguish between different continental origins. However, North Eurasia, which constitutes one-third of the world's largest continent, remains severely underrepresented. The dataset used in this study represents 266 populations from 12 North Eurasian countries, including most of the ethnic diversity across Russia's vast territory.

View Article and Find Full Text PDF

The production of recombinant proteins in transgenic plants is becoming an increasingly serious alternative to classical biopharming methods as knowledge about this process grows. , an aquatic plant unique in its anatomy, is a promising expression system that can grow in submerged culture in bioreactors. In our study 8550 explants were subjected to -mediated transformation, and 41 independent hygromycin-resistant lines were obtained, with the transformation efficiency of 0.

View Article and Find Full Text PDF

The availability of colloidal quantum dots with highly efficient, fast and 'non-blinking' near-infrared emission would benefit numerous applications, from advanced optical communication and quantum networks to biomedical diagnostics. Here, we report high-quality near-infrared emitters that are based on well known CdSe/CdS heterostructures. By incorporating an HgS interlayer at the quantum dot core/shell interface, we convert normally visible emitters into highly efficient near-infrared fluorophores.

View Article and Find Full Text PDF

Background: Thaumatin II, a supersweet protein from the African plant katemfe (Thaumatococcus daniellii Benth.), shows promise as a zero-calorie sweetener for use in the food and pharmaceutical industries and for improving the taste of fruit.

Results: We report on the stability of thaumatin in salted and pickled tomatoes, as well as on the effect of thaumatin on the taste quality of processed tomatoes.

View Article and Find Full Text PDF

Various plant-derived promoters can be used to regulate ectopic gene expression in potato. In the present study, four promoters derived from the potato genome have been characterized by the expression of identical cassettes carrying the fusion with the reporter β-glucuronidase () gene. The strengths of , , , and promoters were compared with the conventional constitutive CaMV promoter in various organs (leaves, stems, roots, and tubers) of greenhouse-grown plants.

View Article and Find Full Text PDF

Colloidal semiconductor quantum dots (QDs) are attractive materials for realizing highly flexible, solution-processable optical gain media, but they are difficult to use in lasing because of complications associated with extremely short optical-gain lifetimes limited by nonradiative Auger recombination. By combining compositional grading of the QD's interior for hindering Auger decay with postsynthetic charging for suppressing parasitic ground-state absorption, we can reduce the lasing threshold to values below the single-exciton-per-dot limit. As a favorable departure from traditional multi-exciton-based lasing schemes, our approach should facilitate the development of solution-processable lasing devices and thereby help to extend the reach of lasing technologies into areas not accessible with traditional, epitaxially grown semiconductor materials.

View Article and Find Full Text PDF

To date, the expression of recombinant proteins in transgenic plants is becoming a powerful alternative to classical expression methods. Special efforts are directed to the development of contained cultivation systems based on cell culture or rhyzosecretion, which reliably prevents the heterologous DNA releasing into the environment. A promising object for the development of such systems is the tiny aquatic plant of , which can be used as a dipped culture in bioreactors.

View Article and Find Full Text PDF

The amino acid sequence of the extracellular domain of the virus-encoded M2 matrix protein (peptide M2e) is conserved among all subtypes of influenza A strains, enabling the development of a broad-range vaccine against them. We expressed M2e from avian influenza virus A/chicken/Kurgan/5/2005 (H5N1) in nuclear-transformed duckweed plants for further development of an avian influenza vaccine. The 30-amino acid N-terminal fragment of M2, including M2e (denoted M130), was selected for expression.

View Article and Find Full Text PDF

In recent years, monolayer organic field-effect devices such as transistors and sensors have demonstrated their high potential. In contrast, monolayer electroluminescent organic field-effect devices are still in their infancy. One of the key challenges here is to create an organic material that self-organizes in a monolayer and combines efficient charge transport with luminescence.

View Article and Find Full Text PDF

Small push-pull molecules attract much attention as prospective donor materials for organic solar cells (OSCs). By chemical engineering, it is possible to combine a number of attractive properties such as broad absorption, efficient charge separation, and vacuum and solution processabilities in a single molecule. Here we report the synthesis and early time photophysics of such a molecule, TPA-2T-DCV-Me, based on the triphenylamine (TPA) donor core and dicyanovinyl (DCV) acceptor end group connected by a thiophene bridge.

View Article and Find Full Text PDF

Morphology of organic photovoltaic bulk heterojunctions (BHJs) - a nanoscale texture of the donor and acceptor phases - is one of the key factors influencing efficiency of organic solar cells. Detailed knowledge of the morphology is hampered by the fact that it is notoriously difficult to investigate by microscopic methods. Here we all-optically track the exciton harvesting dynamics in the fullerene acceptor phase from which subdivision of the fullerene domain sizes into the mixed phase (2-15 nm) and large (>50 nm) domains is readily obtained via the Monte-Carlo simulations.

View Article and Find Full Text PDF

Thaumatin, a supersweet protein from the African plant katemfe (Thaumatococcus daniellii Benth.), is a promising zero-calorie sweetener for use in the food and pharmaceutical industries. Due to limited natural sources of thaumatin, its production using transgenic plants is an advantageous alternative.

View Article and Find Full Text PDF

Exciton diffusion in organic materials provides the operational basis for functioning of such devices as organic solar cells and light-emitting diodes. Here we track the exciton diffusion process in organic semiconductors in real time with a novel technique based on femtosecond photoinduced absorption spectroscopy. Using vacuum-deposited C_{70} layers as a model system, we demonstrate an extremely high diffusion coefficient of D≈3.

View Article and Find Full Text PDF