Petr Nikitin - Academia.edu (original) (raw)
Papers by Petr Nikitin
Fiber Optic and Laser Sensors IX, 1991
ABSTRACT Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields... more ABSTRACT Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and electric current sensors design. Different compositions of semimagnetic semiconductors were grown to measure high frequency magnetic fields (up to several GHz). For moderate frequency sensors < 50 MHz the most perspective material was found to be Bi-substituted yttrium-iron garnets. Several ways to achieve high sensitivity and wide frequency band are discussed. Sensors on the basis of the investigated materials for various spheres of applications were constructed.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Solid State Phenomena, 2015
The time of visualization of proliferation centers of glial tumors in rats by the contrastenhance... more The time of visualization of proliferation centers of glial tumors in rats by the contrastenhanced magnetic resonance imaging (MRI) has been reduced up to 3 -4 days since inoculation by consecutive intravenous injections of dextran-ferrite (DF) nanoparticles and gadolinium-based contrast agent Magnevist®. The well controllable conditions for combined photodynamic magnetothermochemotherapy of the revealed tumors have been achieved by MRI and quantified mapping of the DF particles in the rat's organs and tumors realized by an electronic sensor with inductive coils using non-linear magnetization of the particles. As a result of the proposed therapy, the life span of the rats with glioma (GC6) and glioblastoma (GB 101/8) increased by up to 166% and 74%, respectively.
Probe measurements were performed on the electric field near a plasma generated in air by means o... more Probe measurements were performed on the electric field near a plasma generated in air by means of pulsed-CO2-laser-induced breakdown. Probe signal amplitude was studied as a function of radiation intensity in the range of 10 to the 7th to 10 to the 8th W/sq cm and of the distance between probe and plasma. The appearance of the electric field in the plasma is ascribed to charge separation at the optical detonation wave front. Results are compared with those in which plasma was generated by a high-power neodymium laser beam.
Proceedings of SPIE - The International Society for Optical Engineering
Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and elec... more Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and electric current sensors design. Different compositions of semimagnetic semiconductors were grown to measure high frequency magnetic fields (up to several GHz). For moderate frequency sensors < 50 MHz the most perspective material was found to be Bi-substituted yttrium-iron garnets. Several ways to achieve high sensitivity and wide frequency band are discussed. Sensors on the basis of the investigated materials for various spheres of applications were constructed.
Technical Physics Letters
Fiber Optic Sensor Technology and Applications 2001, 2002
ABSTRACT An optical method has been proposed and successfully tested for direct detection of bioc... more ABSTRACT An optical method has been proposed and successfully tested for direct detection of biochemical reactions on a surface, which is insensitive to variations of the radiation intensity and refractive index of a solution. The method is based on detection of the spectrum of the reflected or transmitted radiation modulated by the interference in a sensitive layer of large thickness (several tens and hundreds of microns), which can be a microscope cover glass with a deposited receptor layer. A change in the phase of the interference pattern in this spectrum is used as an information signal about a change in the thickness of the sensitive layer caused by a biochemical reaction. Single- and multichannel (up to 96 channels) devices have been designed to study reactions of binding and detachment of proteins in real time. The root-mean-square noise of the prototypes expressed in the layer thickness was 3 pm.
Soviet Journal of Quantum Electronics, 1983
ABSTRACT An experimental investigation was made of the factors influencing the threshold laser in... more ABSTRACT An experimental investigation was made of the factors influencing the threshold laser intensity I* for the formation of a plasma when series of radiation pulses of wavelength 308 nm and overall duration 30 nsec interacted with solid targets. Two mechanisms influencing I* were established: laser cleaning, which increased I*, and stimulated rearrangement of the illuminated surface zone by periodic laser action, which lowered I*. It was found that by recording certain optical characteristics of the region where the laser radiation interacted with the target one could provide a criterion for stabilizing I*.
Soviet Journal of Quantum Electronics, 1981
ABSTRACT A probe method was used to investigate the spatial and temporal distribution of the elec... more ABSTRACT A probe method was used to investigate the spatial and temporal distribution of the electric currents in the vicinity of an air-breakdown plasma produced by CO2 laser radiation of intensity 107–108 W/cm2. In the optical detonation regime a system of currents in the form of a fountain appeared before the plasma became detached from the target surface. Electron currents flowed out of the target in the region of the focal spot and returned to the target outside this spot. The total current to a target having dimensions substantially exceeding those of the illuminated spot was equal to zero at each moment of time. It was discovered that on passing to a predetonation mechanism of the plasma development the current signal in the region of the illuminated spot acquired an oscillatory form, its duration being correlated with that of intense plasma luminescence. A mechanism is proposed for the formation of such signals, resulting from the development of turbulent motion in the laser plasma. Electric current signals were also recorded on arrival of gas shock waves at the probe. The experimental data obtained were explained qualitatively in terms of charge separation in plasma inhomogeneities and at the shock front, where gradients of the electron density and temperature existed.
Sensors and Actuators A: Physical, 2001
Magnetotransport properties of Hg 1Àx Cr x Se and Hg 1Àx Eu x Te crystals grown by a modi®ed Brid... more Magnetotransport properties of Hg 1Àx Cr x Se and Hg 1Àx Eu x Te crystals grown by a modi®ed Bridgman method have been studied. Structural characterization of the Hg 1Àx Cr x Se crystals showed good homogeneity for compositions x < 0:05, while samples with higher chromium content included macroscopic needle-like inclusions. It has been found that the inner part of each inclusion is amorphous CrSe and the boundary regions are ternary HgCr 2 Se 4 . Depending on the magnetic ®eld direction different kinds of the temperature dependence of the magnetoresistance DR/R have been found. At room temperature the value of DR/R can reach 100% for the Hg 1Àx Eu x Te crystal. This makes the studied semimagnetic semiconductors an attractive magnetoresistive material for magnetic ®eld sensors. #
Acta naturae, 2014
A method for effective development of solid-phase immunoassays on a glass surface and for optimiz... more A method for effective development of solid-phase immunoassays on a glass surface and for optimization of related protocols by highly sensitive quantitative monitoring of each assay step has been proposed and experimentally implemented. The method is based on the spectral correlation interferometry (SCI) that allows real-time measuring of the thickness of a biomolecular layer bound to the recognition molecular receptors on the sensor chip surface. The method is realized with compact 3-channel SCI-biosensors that employ as the sensor chips standard cover glass slips without deposition of any additional films. Different schemes for antibody immobilization on a glass surface have been experimentally compared and optimized toward a higher sorption capacity of the sensor chips. Comparative characterization of the kinetics of each immunoassay stage has been implemented with the optimized protocols: i) covalent immobilization of antibody on an epoxylated surface and ii) biotinylated antibo...
ABSTRACT The CdTe/Cd1–x Mn x Te quantum well structures have been grown by pulsed laser depositio... more ABSTRACT The CdTe/Cd1–x Mn x Te quantum well structures have been grown by pulsed laser deposition. X-ray diffraction analysis demonstrates high structural quality of the deposited layers and nanostructures. In the magnetoabsorption spectra the large Zeeman splitting of exciton peak which is corresponded to the heavy-hole exciton transition in the CdTe quantum well layers is revealed. The Faraday rotation spectra of the superlattices is interpreted in framework of the exciton transition for the Cd1–x Mn x Te layers at a higher photon energy. Influence of different factors on behavior of the Zeeman splitting and the Faraday rotation in the studied nanostructures is discussed.
Quantum Electronics, 1998
ABSTRACT The method of laser deposition from a composite target was used to prepare Cd1-xMnxTe na... more ABSTRACT The method of laser deposition from a composite target was used to prepare Cd1-xMnxTe nanocrystals embedded in an SiO2 dielectric matrix. A study of the Faraday effect in nanocrystals of this semimagnetic semiconductor revealed enhancement of this effect, compared with bulk crystals. This was attributed to an increase in the oscillator strengths of exciton transitions and to the difference between these strengths in an external magnetic field. At helium temperatures the magnetic field dependence of the Faraday rotation in the nanocrystals was linear in fields up to 200 kOe and the temperature dependence of the rotation in the range 4.2–30 K had a singularity associated with a transition of the nanoparticles from the paramagnetic state to a spin glass. The temperature of this transition in the investigated nanocrystals was higher than the 'cooling' point of bulk semimagnetic semiconductors.
MRI‐Adaptive Magneto‐Thermo‐Chemotherapy for Improved Cancer Treatment. [AIP Conference Proceedin... more MRI‐Adaptive Magneto‐Thermo‐Chemotherapy for Improved Cancer Treatment. [AIP Conference Proceedings 1311, 447 (2010)]. Nikolai A. Brusentsov, Yuri A. Pirogov, Nikolai V. Anisimov, Vitaly A. Polianski, Mikhail R. Lichinicer ...
Quantitative detection of magnetic nanoparticles (MP) in vivo is very important for various biome... more Quantitative detection of magnetic nanoparticles (MP) in vivo is very important for various biomedical applications. Our original detection method based on non‐linear MP magnetization has been modified for non‐invasive in vivo mapping of the MP distribution among different organs ...
Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97), 1997
The new concept of a Si-based surface plasmon resonance (SPR) sensor has been developed and succe... more The new concept of a Si-based surface plasmon resonance (SPR) sensor has been developed and successfully applied to chemical sensing. The sensitivity to nitrogen dioxide has been estimated at the level of tens of ppb. The Si-based SPR scheme provides an additional surface-enhanced Raman scattering (SERS) channel for data acquisition with spectroscopic selectivity and amplified sensitivity. Using two different SPR
Sensors and Actuators A: Physical, 1998
A number of soft ferromagnetic compositions have been used to fabricate thin-film cores for magne... more A number of soft ferromagnetic compositions have been used to fabricate thin-film cores for magnetic sensor microsystems. Techniques based on magnetron sputtering and laser ablation deposition have been extensively explored. The properties of the films have been found to depend strongly on a particular deposition regime and the type of material and, weakly, on an a priori difference between the
Optical Sensors for Environmental and Chemical Process Monitoring, 1995
ABSTRACT An optical biosensor has been developed for detection of pesticides, based on surface pl... more ABSTRACT An optical biosensor has been developed for detection of pesticides, based on surface plasmon resonance (SPR) technique. Concentration of the pesticides was measured in liquid or gas. We specially originated organic film on a disposable element. A setup on the base of Kretschmann arrangement was improved by using a computer-controlled angular scanning system. The detection concentration limit of dinitrophenole (DNP) was 10-9 M. Some samples exhibited effect down to 10-11 M of DNP. The results obtained provide reason for further development of SPR sensor as applied to pesticides monitoring.
Second European Conference on Smart Structures and Materials, 1994
Fiber Optic and Laser Sensors IX, 1991
ABSTRACT Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields... more ABSTRACT Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and electric current sensors design. Different compositions of semimagnetic semiconductors were grown to measure high frequency magnetic fields (up to several GHz). For moderate frequency sensors < 50 MHz the most perspective material was found to be Bi-substituted yttrium-iron garnets. Several ways to achieve high sensitivity and wide frequency band are discussed. Sensors on the basis of the investigated materials for various spheres of applications were constructed.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Solid State Phenomena, 2015
The time of visualization of proliferation centers of glial tumors in rats by the contrastenhance... more The time of visualization of proliferation centers of glial tumors in rats by the contrastenhanced magnetic resonance imaging (MRI) has been reduced up to 3 -4 days since inoculation by consecutive intravenous injections of dextran-ferrite (DF) nanoparticles and gadolinium-based contrast agent Magnevist®. The well controllable conditions for combined photodynamic magnetothermochemotherapy of the revealed tumors have been achieved by MRI and quantified mapping of the DF particles in the rat's organs and tumors realized by an electronic sensor with inductive coils using non-linear magnetization of the particles. As a result of the proposed therapy, the life span of the rats with glioma (GC6) and glioblastoma (GB 101/8) increased by up to 166% and 74%, respectively.
Probe measurements were performed on the electric field near a plasma generated in air by means o... more Probe measurements were performed on the electric field near a plasma generated in air by means of pulsed-CO2-laser-induced breakdown. Probe signal amplitude was studied as a function of radiation intensity in the range of 10 to the 7th to 10 to the 8th W/sq cm and of the distance between probe and plasma. The appearance of the electric field in the plasma is ascribed to charge separation at the optical detonation wave front. Results are compared with those in which plasma was generated by a high-power neodymium laser beam.
Proceedings of SPIE - The International Society for Optical Engineering
Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and elec... more Magnetic materials with high Faraday effect were studied for fiber-optic magnetic fields and electric current sensors design. Different compositions of semimagnetic semiconductors were grown to measure high frequency magnetic fields (up to several GHz). For moderate frequency sensors < 50 MHz the most perspective material was found to be Bi-substituted yttrium-iron garnets. Several ways to achieve high sensitivity and wide frequency band are discussed. Sensors on the basis of the investigated materials for various spheres of applications were constructed.
Technical Physics Letters
Fiber Optic Sensor Technology and Applications 2001, 2002
ABSTRACT An optical method has been proposed and successfully tested for direct detection of bioc... more ABSTRACT An optical method has been proposed and successfully tested for direct detection of biochemical reactions on a surface, which is insensitive to variations of the radiation intensity and refractive index of a solution. The method is based on detection of the spectrum of the reflected or transmitted radiation modulated by the interference in a sensitive layer of large thickness (several tens and hundreds of microns), which can be a microscope cover glass with a deposited receptor layer. A change in the phase of the interference pattern in this spectrum is used as an information signal about a change in the thickness of the sensitive layer caused by a biochemical reaction. Single- and multichannel (up to 96 channels) devices have been designed to study reactions of binding and detachment of proteins in real time. The root-mean-square noise of the prototypes expressed in the layer thickness was 3 pm.
Soviet Journal of Quantum Electronics, 1983
ABSTRACT An experimental investigation was made of the factors influencing the threshold laser in... more ABSTRACT An experimental investigation was made of the factors influencing the threshold laser intensity I* for the formation of a plasma when series of radiation pulses of wavelength 308 nm and overall duration 30 nsec interacted with solid targets. Two mechanisms influencing I* were established: laser cleaning, which increased I*, and stimulated rearrangement of the illuminated surface zone by periodic laser action, which lowered I*. It was found that by recording certain optical characteristics of the region where the laser radiation interacted with the target one could provide a criterion for stabilizing I*.
Soviet Journal of Quantum Electronics, 1981
ABSTRACT A probe method was used to investigate the spatial and temporal distribution of the elec... more ABSTRACT A probe method was used to investigate the spatial and temporal distribution of the electric currents in the vicinity of an air-breakdown plasma produced by CO2 laser radiation of intensity 107–108 W/cm2. In the optical detonation regime a system of currents in the form of a fountain appeared before the plasma became detached from the target surface. Electron currents flowed out of the target in the region of the focal spot and returned to the target outside this spot. The total current to a target having dimensions substantially exceeding those of the illuminated spot was equal to zero at each moment of time. It was discovered that on passing to a predetonation mechanism of the plasma development the current signal in the region of the illuminated spot acquired an oscillatory form, its duration being correlated with that of intense plasma luminescence. A mechanism is proposed for the formation of such signals, resulting from the development of turbulent motion in the laser plasma. Electric current signals were also recorded on arrival of gas shock waves at the probe. The experimental data obtained were explained qualitatively in terms of charge separation in plasma inhomogeneities and at the shock front, where gradients of the electron density and temperature existed.
Sensors and Actuators A: Physical, 2001
Magnetotransport properties of Hg 1Àx Cr x Se and Hg 1Àx Eu x Te crystals grown by a modi®ed Brid... more Magnetotransport properties of Hg 1Àx Cr x Se and Hg 1Àx Eu x Te crystals grown by a modi®ed Bridgman method have been studied. Structural characterization of the Hg 1Àx Cr x Se crystals showed good homogeneity for compositions x < 0:05, while samples with higher chromium content included macroscopic needle-like inclusions. It has been found that the inner part of each inclusion is amorphous CrSe and the boundary regions are ternary HgCr 2 Se 4 . Depending on the magnetic ®eld direction different kinds of the temperature dependence of the magnetoresistance DR/R have been found. At room temperature the value of DR/R can reach 100% for the Hg 1Àx Eu x Te crystal. This makes the studied semimagnetic semiconductors an attractive magnetoresistive material for magnetic ®eld sensors. #
Acta naturae, 2014
A method for effective development of solid-phase immunoassays on a glass surface and for optimiz... more A method for effective development of solid-phase immunoassays on a glass surface and for optimization of related protocols by highly sensitive quantitative monitoring of each assay step has been proposed and experimentally implemented. The method is based on the spectral correlation interferometry (SCI) that allows real-time measuring of the thickness of a biomolecular layer bound to the recognition molecular receptors on the sensor chip surface. The method is realized with compact 3-channel SCI-biosensors that employ as the sensor chips standard cover glass slips without deposition of any additional films. Different schemes for antibody immobilization on a glass surface have been experimentally compared and optimized toward a higher sorption capacity of the sensor chips. Comparative characterization of the kinetics of each immunoassay stage has been implemented with the optimized protocols: i) covalent immobilization of antibody on an epoxylated surface and ii) biotinylated antibo...
ABSTRACT The CdTe/Cd1–x Mn x Te quantum well structures have been grown by pulsed laser depositio... more ABSTRACT The CdTe/Cd1–x Mn x Te quantum well structures have been grown by pulsed laser deposition. X-ray diffraction analysis demonstrates high structural quality of the deposited layers and nanostructures. In the magnetoabsorption spectra the large Zeeman splitting of exciton peak which is corresponded to the heavy-hole exciton transition in the CdTe quantum well layers is revealed. The Faraday rotation spectra of the superlattices is interpreted in framework of the exciton transition for the Cd1–x Mn x Te layers at a higher photon energy. Influence of different factors on behavior of the Zeeman splitting and the Faraday rotation in the studied nanostructures is discussed.
Quantum Electronics, 1998
ABSTRACT The method of laser deposition from a composite target was used to prepare Cd1-xMnxTe na... more ABSTRACT The method of laser deposition from a composite target was used to prepare Cd1-xMnxTe nanocrystals embedded in an SiO2 dielectric matrix. A study of the Faraday effect in nanocrystals of this semimagnetic semiconductor revealed enhancement of this effect, compared with bulk crystals. This was attributed to an increase in the oscillator strengths of exciton transitions and to the difference between these strengths in an external magnetic field. At helium temperatures the magnetic field dependence of the Faraday rotation in the nanocrystals was linear in fields up to 200 kOe and the temperature dependence of the rotation in the range 4.2–30 K had a singularity associated with a transition of the nanoparticles from the paramagnetic state to a spin glass. The temperature of this transition in the investigated nanocrystals was higher than the 'cooling' point of bulk semimagnetic semiconductors.
MRI‐Adaptive Magneto‐Thermo‐Chemotherapy for Improved Cancer Treatment. [AIP Conference Proceedin... more MRI‐Adaptive Magneto‐Thermo‐Chemotherapy for Improved Cancer Treatment. [AIP Conference Proceedings 1311, 447 (2010)]. Nikolai A. Brusentsov, Yuri A. Pirogov, Nikolai V. Anisimov, Vitaly A. Polianski, Mikhail R. Lichinicer ...
Quantitative detection of magnetic nanoparticles (MP) in vivo is very important for various biome... more Quantitative detection of magnetic nanoparticles (MP) in vivo is very important for various biomedical applications. Our original detection method based on non‐linear MP magnetization has been modified for non‐invasive in vivo mapping of the MP distribution among different organs ...
Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97), 1997
The new concept of a Si-based surface plasmon resonance (SPR) sensor has been developed and succe... more The new concept of a Si-based surface plasmon resonance (SPR) sensor has been developed and successfully applied to chemical sensing. The sensitivity to nitrogen dioxide has been estimated at the level of tens of ppb. The Si-based SPR scheme provides an additional surface-enhanced Raman scattering (SERS) channel for data acquisition with spectroscopic selectivity and amplified sensitivity. Using two different SPR
Sensors and Actuators A: Physical, 1998
A number of soft ferromagnetic compositions have been used to fabricate thin-film cores for magne... more A number of soft ferromagnetic compositions have been used to fabricate thin-film cores for magnetic sensor microsystems. Techniques based on magnetron sputtering and laser ablation deposition have been extensively explored. The properties of the films have been found to depend strongly on a particular deposition regime and the type of material and, weakly, on an a priori difference between the
Optical Sensors for Environmental and Chemical Process Monitoring, 1995
ABSTRACT An optical biosensor has been developed for detection of pesticides, based on surface pl... more ABSTRACT An optical biosensor has been developed for detection of pesticides, based on surface plasmon resonance (SPR) technique. Concentration of the pesticides was measured in liquid or gas. We specially originated organic film on a disposable element. A setup on the base of Kretschmann arrangement was improved by using a computer-controlled angular scanning system. The detection concentration limit of dinitrophenole (DNP) was 10-9 M. Some samples exhibited effect down to 10-11 M of DNP. The results obtained provide reason for further development of SPR sensor as applied to pesticides monitoring.
Second European Conference on Smart Structures and Materials, 1994