[Monitoring of brightness temperature fluctuation of water in SHF range].

The purpose of the research consisted in detection of fluctuation of brightness temperature (TSHF) of water in the area of the temperature Т = 42°Ð¡ (that is critical for human) during its evaporation by SHF radiometry. Methods: Monitoring of the changes in brightness temperature of water in superhigh frequency (SHF) range (3.8-4.2 GHz) near the phase transition temperature of water Т = 42°Ð¡ during its evaporation in the cone dielectric cell. The brightness temperature measurements were carried out using radiometer. Results: Fluctuation with maximum of brightness temperature was detected in 3.8-4.2 GHz frequency range near at the temperature of water Т = 42°Ð¡. It was characteristic for these TSHF fluctuations that brightness temperature rise time in this range of frequencies in ~4°Ð¡ temperature range with 0.05-15°Ð¡/min gradient and a sharp decrease during 10 s connected with measuring vapor conditions. Then nonintensive fluctuation series was observed. At that, the environment temperature remained constant. Conclusion: The significant increasing in brightness temperature of water during its evaporation in SHF range near the temperature of Т ~42°Ð¡ were detected. It was shown that for water, ТSHF pull with the amplitude DТSHF ~4°C are observed. At the same time, thermodynamic temperature virtually does not change. The observed effects can be used in the development of the systems for diadnostics of pathologies in human and analytical system.

[AFM fishing of proteins under impulse electric field]. / ASM-fishing belka v impul'snom élektricheskom pole.

A combination of (atomic force microscopy)-based fishing (AFM-fishing) and mass spectrometry allows to capture protein molecules from solutions, concentrate and visualize them on an atomically flat surface of the AFM chip and identify by subsequent mass spectrometric analysis. In order to increase the AFM-fishing efficiency we have applied pulsed voltage with the rise time of the front of about 1 ns to the AFM chip. The AFM-chip was made using a conductive material, highly oriented pyrolytic graphite (HOPG). The increased efficiency of AFM-fishing has been demonstrated using detection of cytochrome b5 protein. Selection of the stimulating pulse with a rise time of 1 ns, corresponding to the GHz frequency range, by the effect of intrinsic emission from water observed in this frequency range during water injection into the cell.

Detection of microwave radiation of cytochrome CYP102 A1 solution during the enzyme reaction.

Microwave radiation at 3.4-4.2 GHz frequency of the cytochrome P450 CYP102 A1 (BM3) solution was registered during the lauric acid hydroxylation reaction. The microwave radiation generation was shown to occur following the addition of electron donor NADPH to a system containing an enzyme and a substrate. The radiation occurs for the enzyme solutions with enzyme concentrations of 10-8 and 10-9 Ðœ. The microwave radiation effect elicited by the aqueous enzyme solution was observed for the first time. The results obtained can be used to elaborate a new approach to enzyme systems research, including studying of the mechanism of interaction of a functioning enzyme system with microenvironment.

[Registration of the protein in the serum with a field-effect nanotransistor biosensor].

A method for detection of cancer-associated protein D-NFATc1 in serum using nanowire (NW) biosensor based on field-effect nanotransistor is developed. Field-effect nanotransistor was fabricated on the basis of «silicon-on-insulator¼ structures. For the biospecific detection of target protein, the NW surface was modified with aptamers against the target protein. Using the 3 um-NW enabled to obtain stable source-drain characteristics and to register D-NFATc1 in serum at concentration of 2.5 x 1014 M in the mode of drain-source current vs. gate voltage characteristics measurements. Data collection in the mode of drain-source current vs. gate voltage characteristics measurements was carried out with the use of high-speed data collection system running TURBO NBS software.

SHF radiation from albumin solution upon external excitation.

The purpose of the research consisted in the measurement of nonequilibrium radiation in superhigh frequency (SHF) range from aqueous solution of albumin upon its mechanical stimulation. Methods: the monitoring of change in the ratio between brightness temperatures TSHF and TIR values after the mechanical stimulation of aqueous solution of albumin in the measuring cell at 35-39°Ð¡. The measurements of brightness temperatures were carried out with use of radiothermometer. SHF frequency range corresponded to 3.4-4.2 GHz, SHF frequency range corresponded to 8-13 mm. Results: It was found that mechanical stimulation of aqueous solution of albumin at the temperature ~39°Ð¡, the change in the ratio between TSHF and TIR occurs. This corresponds to emergence of nonequilibrium SHF radiation from the solution near the phase transition with ~39°Ð¡ temperature. Conclusion: The effect of emergence of nonequilibrium SHF radiation from protein solution near its temperature 39°Ð¡ was found. This temperature corresponds to the temperature of human organism upon a number of pathological states connected with inflammatory processes. The discovered effect can be used in the development of novel non-invasive methods of disease diagnostics.

Monitoring of microwave emission of HRP system during the enzyme functioning.

Monitoring of microwave emission from aqueous solution of horseradish peroxidase (HRP) in the process of the enzyme functioning was carried out. For the monitoring, a system containing HRP, luminol and Н2О2 was employed. Microwave emission measurements were carried out in the 3.4-4.2 GHz frequency range using the active and passive modes (active-mode and passive-mode measurements). In the active mode, excitation of the solution in the pulsed electromagnetic field was accomplished. In the passive mode, no excitation was induced. It appears that the passive-mode measurements taken in the course of the peroxidase reaction in the enzyme system have shown a 0.5 °Ð¡ increase of the microwave signal. Upon the active-mode measurements, taken in the same reaction conditions, the forced excitation of the solution has also led to the increase (by 2 °Ð¡) of the level of the microwave signal - i.e. to its 4-fold enhancement compared to the signal obtained in passive-mode measurements.

[Atomic force microscopy monitoring of temperature dependence of cytochrome BM3 oligomeric state].

The change in temperature is one of the factors affecting the activity of enzymes. In this work thermal denaturation and aggregation of cytochrome P450 BM3 were studied by atomic force microscopy. To determine specific temperature transitions the fluorescence analysis was used. In the low melting temperature range, 10-33 degrees C, a decrease in the fluorescence intensity of aromatic residues was observed with an increase in the fluorescence intensity of flavin groups. Protein melting in this range indicated three narrow S-shaped cooperative transitions at temperatures 16, 22 and 29 degrees C. Atomic force microscopy analysis in this temperature range showed that the shape of BM3 molecules remained globular in the form of compact objects (heights h < 7 nm, lateral dimensions d < 50 nm), but protein oligomeric state changed. The first two transitions were accompanied by a decrease in the degree of oligomerization and the third one was accompanied by its increase.

[Microwave emission from water in bioanalytical systems].

Mechanical stimulation of aqueous protein solution was found to be accompanied by electromagnetic radiation in the superhigh frequency range. This radiation was observed at solution temperatures near the phase transitions of water. This effect may occur in various bioanalytical systems, associated with injection of aqueous solutions in these systems, and may have impact on the results of bioalytical measurements. The discovered effect of generation of nonequilibrium microwave emission of water medium (which is the main component of the organism) in the 38-39°C temperature range, i.e. in the range of elevated temperature of the organism (which accompanies pathological condition in humans upon inflammatory diseases, i.e., infactious etc.) may be used for development of new non-invasive methods of disease diagnostics.

[Bioavailability of oral drug formulations and methods for its improvement].

The recent studies in nanotechnology resulted in the development of novel formulations with improved bioavailability. This is especially important for oral administered drugs as the most convenient formulations. The current review deals with the processes occurring at the gastro-intestinal (GI) tract and their influence on the drug form. The increase of bioavailability of the drug may be achieved through designing novel formulations according to the specific drug properties. They include capsules that release pharmaceutical agents at various parts of the GI tract, floating systems that prolong the presence of the drug in the GI tract, dispersed forms with surface-active soluble polymers, micelles that carry poor-soluble drugs inside their non-polar core, agents that facilitate tight junction opening, such as caprate and chitosan, and lipid-based formulations. The own data show the stimulating influence of phospholipid nanoparticles on peroral absorption of drug indomethacin in rats and on passage of transport marker and drugs through Caco-2 cell monolayer in vitro. The review summarizes current understanding of factors that influence the bioavailability of the oral drug forms, currently used models for pharmacokinetic studies, and various approaches to developing novel pharmaceutical forms that increase the bioavailability of the drugs.

Study of dynamic adsorption behavior of large-size protein-bearing particles.

The subject of this paper is an investigation of the peculiarities of dynamic adsorption behavior of nanoparticles. For this purpose, virus-mimicking synthetic particles bearing different proteins at their outer surface were specially constructed using two approaches, e.g. the cross-linking of proteins and modification of polystyrene microsphere surface by proteins. Two chromatographic modes, namely ion-exchange and affinity liquid chromatography on ultra-short monolithic columns [Convective Interaction Media (CIM) DEAE and CIM QA disks] have been used as a tool for dynamic adsorption experiments. Such parameters as maximum adsorption capacity and its dependence on applied flow rate were established and compared with those obtained for individual proteins. Similarly to individual proteins, it was shown that the maximum of adsorption capacity was not changed at different flow rates. In addition, the permeability of porous space of used monolithic sorbents appeared to be sufficient for efficient separation of large particles and quite similar to the well-studied process applied for individual proteins.