0000000000008635

AUTHOR

Ryszard Olchawa

0000-0002-4950-730x

showing 13 related works from this author

Impact of humic acids on EYL liposome membranes: ESR method

2015

Abstract In this paper, the effects of model (commercial) and natural (extracted from peat) humic substances on the membrane of liposomes formed with egg yolk lecithin (EYL) are presented. In our research, mass concentrations of fulvic and humic acids were used, which in relation to lecithin varied from 0% to 13%. To study membrane fluidity, electron spin resonance (EPR) was used with two spin probes, penetrating various regions of the lipid bilayer. The effects of model and natural humic substances (humic acids – HAs and fulvic acids – FAs) on the lipid membrane in different regions were researched: the lipid-water interphase, and in the middle of the lipid bilayer. It was shown that FA an…

esr methodNuclear and High Energy PhysicsLiposomeChromatographyhumic substanceseyl liposomesScienceQCondensed Matter Physicscomplex mixturesMembraneNuclear Energy and EngineeringSafety Risk Reliability and QualityWaste Management and DisposalInstrumentationNukleonika
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The impact of humic and fulvic acids on the dynamic properties of liposome membranes: the ESR method

2013

This paper presents the results of research on the influence of two fractions of humic substances (HS): fulvic acids (FA) and humic acids (HA), as a function of concentration, on the liposome membranes formed from egg yolk lecithin (EYL). The concentration of HS in relation to EYL changed from 0% to 10% by weight. The influence of HS on various areas of membranes: interphase water-lipid, in the lipid layer just below the polar part of the membrane and in the middle of the lipid bilayer, was investigated by different spin labels (TEMPO, DOXYL 5, DOXYL 16). The study showed that HA slightly decreased the fluidity of the analyzed membranes on the surface layer, while FA significantly liquidate…

LiposomeChromatographyfood.ingredientESR methodFree RadicalsMembrane FluidityChemistryhumic substancesRadicalLipid BilayersElectron Spin Resonance SpectroscopyPharmaceutical ScienceLecithinKineticsfoodMembraneYolkLiposomesBenzopyransSpin LabelsInterphaseEYL liposomesSurface layerLipid bilayerNuclear Magnetic Resonance BiomolecularJournal of Liposome Research
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The Possibilities of Using BCI Technology in Biomedical Engineering

2018

The paper presents capabilities of building devices dedicated for persons with heavy mobility dysfunction and indicates the role of interfaces connecting brain with computer (Brain Computer Interface, BCI). Impulses coming from closing eyes, clenching teeth, and tongue movement were proposed as optimal in controlling the applications that manage executable systems. A group of electrodes giving a strong electric signal characteristic for the activity were designated and on the basis of conducted research a proposition of a scientific project concerning building of supporting devices for persons with heavy mobility dysfunction was presented.

Computer scienceClenching teeth010401 analytical chemistryBrain Computer Interface020206 networking & telecommunications02 engineering and technologycomputer.file_format01 natural sciences0104 chemical sciencesElectric signalClosing eyesHuman–computer interaction0202 electrical engineering electronic engineering information engineeringEEGExecutableBiomedical engineeringcomputerTongue movementBrain–computer interface
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Brain Biophysics: Perception, Consciousness, Creativity. Brain Computer Interface (BCI)

2018

The paper presents connections between perception, awareness, and creativity from the biophysical point of view. Attention was drawn to human senses’ limitations and their influence on cognition. The role of interfaces connecting brain with computer and particular role of Brain Computer Interface (BCI) are indicated which the authors believe will be the next stage of human brain supporting technology evolution. It will enable the growth of perception, awareness, and creativity, and consequently lead to social development.

Cognitive sciencemedia_common.quotation_subject010401 analytical chemistryCognitionTechnological evolutionBrain biophysicsCreativityPositive feedback01 natural sciences0104 chemical sciences03 medical and health sciences0302 clinical medicinePerceptionConsciousnessPsychologyPerception biophysics030217 neurology & neurosurgeryBrain–computer interfacemedia_common
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Two-step impact of Amphotericin B (AmB) on lipid membranes: ESR experiment and computer simulations.

2013

In this study, the electron spin resonance (ESR) method was used to examine the effect of Amphotericin B (AmB) molecules on the fluidity of model membranes made of dipalmitoylphosphatidylcholine (DPPC). The changes occurring under increased AmB concentrations in the spectroscopic parameters of spin probes placed in liposomes were determined. Three probes were used, penetrating the membrane at different depths which allowed the changes in its fluidity to be found in the transverse section. A computer model of the surface layer of membrane, with AmB admixture, was developed and subjected to computer simulation. The effect of changing concentration of the admixture on the binding energy in the…

LiposomeAntifungal AgentsChemistryBinding energyAnalytical chemistryElectron Spin Resonance SpectroscopyPharmaceutical Sciencelaw.inventionchemistry.chemical_compoundMembranelawDipalmitoylphosphatidylcholineAmphotericin BMembrane fluidityComputer SimulationSpin LabelsSurface layerskin and connective tissue diseasesLipid bilayerElectron paramagnetic resonanceJournal of liposome research
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Membrane fluidity and the surface properties of the lipid bilayer: ESR experiment and computer simulation

2009

Penetration of the liposome membranes formed in the gel phase from DPPC (DPPC liposomes) and in the liquid-crystalline phase from egg yolk lecithin (EYL liposomes) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and 16 DOXYL (2-ethyl-2-(15-methoxy-oxopentadecyl)-4,4-dimethyl-3-oxazolidinyloxy) spin probes has been investigated. The penetration process was followed by 120 hours at 24(0)C, using the electron spin resonance (ESR) method. The investigation of the kinetics of the TEMPO probe building into the membranes of both types of liposomes revealed differences appearing 30 minutes after the start of the experiment. The number of TEMPO particles built into the EYL liposome membranes beg…

Liposomefood.ingredient12-DipalmitoylphosphatidylcholineMembrane FluiditySurface PropertiesChemistryBilayerLipid BilayersElectron Spin Resonance SpectroscopyAnalytical chemistryPharmaceutical SciencePenetration (firestop)Lecithinlaw.inventionCyclic N-OxidesMembranefoodlawMembrane fluidityComputer SimulationSpin LabelsLipid bilayerElectron paramagnetic resonanceMonte Carlo MethodJournal of Liposome Research
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The Brain, Mind and Electromagnetic Waves

2021

The functions of electromagnetic waves both as an information carrier and energy field in the impact on the human body have been discussed. Possible consequences of the effect of electromagnetic fields of different frequencies on the human brain and body have been addressed and commented on. The complex nature of electromagnetic phenomena revealed in interactions between humans and the environment, featuring the most relevant hazards, was demonstrated.

0301 basic medicineElectromagnetic fieldPhysicsElectromagnetic wavesElectromagnetic PhenomenaField (physics)BrainMindElectromagnetic radiation03 medical and health sciences030104 developmental biology0302 clinical medicineElectromagnetic smogQuantum electrodynamics030217 neurology & neurosurgeryEnergy (signal processing)
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The dynamics of the surface layer of lipid membranes doped by vanadium complex: computer modeling and EPR studies

2015

Abstract Penetration of the liposome membranes doped with vanadium complex formed in the liquid-crystalline phase from egg yolk lecithin (EYL) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) spin probes has been investigated. The penetration process was followed by 360 hours at 24°C, using the electron spin resonance (EPR) method. The spectroscopic parameter of the partition (F) of this probe indicated that a maximum rigidity of the membrane was at 3% concentration of the vanadium complex. Computer simulations showed that the increase in the rigidity of the membrane corresponds to the closure of gaps in the surface layer of the membrane, and indicates the essential role of the membrane …

Nuclear and High Energy PhysicsScienceDopingmembrane fluidityQAnalytical chemistryVanadiumchemistry.chemical_elementmonte carlo simulationCondensed Matter Physicslaw.inventionMembraneNuclear Energy and EngineeringchemistryChemical engineeringlawepr probeMembrane fluiditySurface layerlipid membraneSafety Risk Reliability and QualityElectron paramagnetic resonanceLipid bilayerWaste Management and DisposalInstrumentationNukleonika
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Virtual Reality Based Simulators for Neurosurgeons - What We Have and What We Hope to Have in the Nearest Future

2018

High levels of manual skills, good visual-motor coordination, excel‐lent imagination and spatial awareness are the main factors determining the success of neurosurgeons. Proficiency in neurosurgical skills used to be acquired through hands-on training in cadaver labs and in real operating theatres under master neurosurgeon supervision. Most recently, virtual reality (VR) and augmented reality (AR) computer simulations have also been considered as tools for education in the neurosurgical training. The authors review existing solutions and present their own concept of a simulator which could become the useful tool for planning, simulation and training of a specific neurosurgical procedure usi…

Spatial contextual awarenessOperating theatresComputer scienceContext (language use)Medical trainingVirtual realityImaging dataField (computer science)Virtual realityNeurosurgical Procedure03 medical and health sciences0302 clinical medicineHuman–computer interaction030220 oncology & carcinogenesisAugmented realityNeurosurgical simulator030217 neurology & neurosurgery
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Computer Simulations of the Electric Interactions between the Phospholipid Head-Groups and Ionic Admixtures in the Membrane Surface

2001

Some phospholipids (e.g. lecithin) form a system of electric dipoles on the membrane surface layer. In the case of lecithin the positive dipole charge is located on the choline and the negative one on the phosphoric molecule group. These dipoles are arranged almost parallel to the membrane surface. Taking the dipole membrane structure as a base for further investigations, a computer model of the electrostatic interaction between the dipole system and the ionic admixture was investigated. The model presumes hexagonal centered or a rectangular flat geometry of the 121 dipoles distribution. The dipoles may rotate freely around round the motionless symmetry axis perpendicular to the system surf…

Thermodynamic equilibriumChemistryLipid BilayersStatic ElectricityBinding energyAnalytical chemistryIonic bondingCharge (physics)Models TheoreticalModels BiologicalMolecular physicsGeneral Biochemistry Genetics and Molecular BiologyIonKineticsElectric dipole momentDipolePhosphatidylcholinesThermodynamicsMoleculeComputer SimulationPhospholipidsZeitschrift für Naturforschung C
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Dynamics of surface of lipid membranes: theoretical considerations and the ESR experiment.

2016

The effect of the surface layer of model membranes on their physical properties was discussed in this paper. The research involved a physical ESR experiment with the use of spin probes and computer simulation based on the Monte Carlo technique. Liposomes formed during the process of sonication of lecithin were scanned in an ESR spectrometer. The membrane surface layer model, represented by the system of electric dipoles arranged in rectangular or hexagonal matrices, was studied. The final states of computer simulations were presented as textures. It was found that in the gel phase some ordered domain structures are formed, while in the liquid–crystal phase we got complex textures comprising…

Models MolecularPhase transition12-DipalmitoylphosphatidylcholineSurface PropertiesMonte Carlo methodBiophysicsAnalytical chemistryMolecular Conformation02 engineering and technologyPhase Transition03 medical and health sciencesSonication0302 clinical medicinePhase (matter)Lipid membraneSurface layerMembrane fluidityLipid bilayerMonte Carlo simulationChemistryCell MembraneElectron Spin Resonance SpectroscopyTemperatureGeneral MedicineHydrogen-Ion ConcentrationESR probe021001 nanoscience & nanotechnologyElectric dipole momentDipoleKineticsMembraneChemical physics030220 oncology & carcinogenesisLiposomesOriginal Article0210 nano-technologyMonte Carlo MethodEuropean biophysics journal : EBJ
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The Influence of Natural and Model Forms of Humic Acids on the Dynamic Parameters of Model Membranes

2016

Abstract In this paper the influence of humic acid concentrations extracted from Histosols (HA-A) and their model forms (HA-B) separated from humic substances commercially produced by Carl Roth GmbH + Co.KG on the dynamic properties of liposome membranes was determined. Differences in the quality of the humic acids (HA-A and HA-B) were determined by the 1HNMR and FTIR methods. Liposomes from the sonication of egg yolk lecithin (EYL) in an aqueous solution and synthetic Dipalmitoylphosphatidylcholine (DPPC) were used. Fluidity of liposome membranes was determined by the EPR technique with spin probes (TEMPO, 16DOIXYL). The electrical parameters of membranes were found using a Keithley 6517 e…

chemistry.chemical_classificationEnvironmental Engineering010504 meteorology & atmospheric sciencesEcology (disciplines)010501 environmental sciences01 natural sciencesNatural (archaeology)MembranechemistryChemical engineeringEnvironmental ChemistryHumic acidSpin label0105 earth and related environmental sciencesEcological Chemistry and Engineering S
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Development of the BCI Device Controlling C++ Software, Based on Existing Open Source Projects

2021

The possibility of using the BCI open source code for building BCI controlled device, based on small AVR or ARM microcontrollers was considered. Some techniques to extract code snippets from other BCI projects were presented in the case of OpenViBE as the code donor. Problem with obtaining driver source codes for factory BCI devices has been pointed out.

Source codeOpenVibeInformationSystems_INFORMATIONINTERFACESANDPRESENTATION(e.g.HCI)Computer sciencebusiness.industrymedia_common.quotation_subjectBCI driversMicrocontrollerInformationSystems_MODELSANDPRINCIPLESSoftwareDevelopment (topology)BCI softwareEmbedded systemCode (cryptography)Factory (object-oriented programming)BCIbusinessBrain–computer interfacemedia_common
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