New Method for Covalent Fluorescent Biomolecule Labeling with Hemicyanine Dye

Fluorescent chromophore, alkylamino-(tetra-hydronaphthalenylidene)- benzothiazolium derivatives (HBTN dyes), are proposed as covalent labels for proteins via aliphatic amino groups. Spectral-luminescent properties of 3-methyl-2-{(E)-[7-(methylamino)-4,4a,5,6-tetra-hydronaphthalen-2(3H)-ylidene]methyl}-1,3-benzothiazol-3-ium chloride (HBTN, R=Me) and its predecessor, 2-[(E)-(7-methoxy-4,4a,5,6-tetrahydronaphthalen-2(3H)-ylidene)methyl]-3-methyl-1,3-benzothia-zol-3-ium chloride (ABTN), are studied for free dyes and in the presence of DNA and BSA. Considerable spectral-luminescent changes accompany the transformation of ABTN into HBTN that allows monitoring conjugation reaction. In presence of DNA and BSA the HBTN increases its emission in 15 and 4 times respectively and becomes strongly fluorescent. The conditions for labeling are developed and a model conjugate of HBTN dye with BSA is synthesized. It was shown that using of HBTN dye as a fluorescent label allows detection by eye of about 3 μg/band of BSA on polyacrylamide gel upon UV-irradiation.     

Generation of high-current relativistic electron beams with stable (for a microsecond) parameters using explosive emission cathodes

Cold explosive emission cathodes, in which a plasma serves as an emitting surface, are used to generate relativistic electron beams with a high current density in a magnetic field. The plasma parameters change within a microsecond, thereby significantly changing the geometry of the electron beam. This paper is a review of techniques for stabilizing the geometry of microsecond high-current relativistic electron beams. It is shown that only a transverse-blade explosive emission cathode in a magnetically insulated diode can generate such beams (500 keV, 3 kA) the current density profile and electron trajectory pitch factor of which remain constant for a microsecond.     

Influence of Nanoparticle Processing on the Thermoelectric Properties of (BixSb1−X)2Te3 Ternary Alloys

The synthesis of phase-pure ternary solutions of tetradymite-type materials (Bi_xSb_1−x)₂Te₃ (x=0.25; 0.50; 0.75) in an ionic liquid approach has been carried out. The nanoparticles are characterized by means of energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy. In addition, the role of different processing approaches on the thermoelectric properties - Seebeck coefficient as well as electrical and thermal conductivity - is demonstrated.     

Synthesis of α-CF3- and α-CCl3 substituted nitrogen heterocycles by aza Diels-Alder and cyclocondensation reactions

Convenient synthetic approaches for α-CF₃- and α-CCl₃ substituted pyridines, hydrogenated pyridines, azanorbornenes, 4H-1,2,4-thiadiazine- and 2H-1,2,6-thiadiazine-1,1-dioxides were developed on the basis of cycloaddition and cyclocondensation reactions of trihaloethaneimines and imidoyl chlorides.     

Distant collaboration in drug discovery: the LINK3D project

The work describes the development of novel software supporting synchronous distant collaboration between scientists involved in drug discovery and development projects. The program allows to visualize and share data as well as to interact in real time using standard intranets and Internet resources. Direct visualization of 2D and 3D molecular structures is supported and original tools for facilitating remote discussion have been integrated. The software is multiplatform (MS-Windows, SGI-IRIX, Linux), allowing for a seamless integration of heterogeneous working environments. The project aims to support collaboration both within and between academic and industrial institutions. Since confidentiality is very important in some scenarios, special attention has been paid to security aspects. The article presents the research carried out to gather the requirements of collaborative software in the field of drug discovery and development and describes the features of the first fully functional prototype obtained. Real-world testing activities carried out on this prototype in order to guarantee its adequacy in diverse environments are also described and discussed.In addition to the mentioned institutions the LINK3D Consortium is constituted by     

Elimination of emission quenching of plasma relativistic microwave generator

The mechanism of the development of the effect of microwave pulse shortening in a plasma relativistic microwave generator with a power of 10⁸ W is determined using numerical simulation. Methods for eliminating the causes of microwave generation quenching are proposed. It is shown that the emission time can be significantly increased.