Karl H . Schoenbach - Academia.edu (original) (raw)
Papers by Karl H . Schoenbach
Biochemical and Biophysical Research Communications, 2007
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Biochemical and Biophysical Research Communications, 2007
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Bioelectrochemistry, 2015
The presence of increased temperature for gene electrotransfer has largely been considered negati... more The presence of increased temperature for gene electrotransfer has largely been considered negative. Many reports have published on the lack of heat from electrotransfer conditions to demonstrate that their effects are from the electrical pulses and not from a rise in temperature. Our hypothesis was to use low levels of maintained heat from an exogenous source to aid in gene electrotransfer. The goal was to increase gene expression and/or reduce electric field. In our study we evaluated high and low electric field conditions from 90V to 45V which had been preheated to 40°C, 43°C, or 45°C. Control groups of non-heated as well as DNA only were included for comparison in all experiments. Luciferase gene expression, viability, and percent cell distribution were measured. Our results indicated a 2-4 fold increase in gene expression that is temperature and field dependent. In addition levels of gene expression can be increased without significant decreases in cell death and in the case of high electric fields no additional cell death. Finally, in all conditions percent cell distribution was increased from the application of heat. From these results, we conclude that various methods may be employed depending on the end user's desired goals. Electric field can be reduced 20-30% while maintaining or slightly increasing gene expression and increasing viability or overall gene expression and percent cell distribution can be increased with low viability.
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31st Plasmadynamics and Lasers Conference, 2000
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2014 IEEE 41st International Conference on Plasma Sciences (ICOPS) held with 2014 IEEE International Conference on High-Power Particle Beams (BEAMS), 2014
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IEEE Transactions on Plasma Science, 2002
IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 ... Nanosecond Pulsed Electric... more IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 ... Nanosecond Pulsed Electric Field (nsPEF) Effects on ... Cells and Tissues: Apoptosis Induction and Tumor ... Stephen J. Beebe, Member, IEEE, PM Fox, LJ Rec, K. Somers, Robert H. Stark, ...
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Applied Physics Letters, 1999
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Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2004
Electrical models for biological cells predict that reducing the duration of applied electrical p... more Electrical models for biological cells predict that reducing the duration of applied electrical pulses to values below the charging time of the outer membrane causes a strong increase in the probability for electric field interactions with intracellular structures. For electric field amplitudes exceeding MV/m such pulses are expected to cause electroporation of cell organelles, with the required electric field amplitude scaling linearly with the inverse of pulse duration. Experimental studies where human cells were exposed to pulsed electric field of up to 300 kV/cm amplitude with duration as short as 10 ns, have confirmed this hypothesis. The observed effects include the breaching of intracellular granule membranes without permanent damage to the cell membrane, abrupt rises in intracellular free calcium levels, and enhanced expression of genes. At increased electric fields, the application of nanosecond pulses induces apoptosis in biological cells, an effect that has been shown to ...
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IEEE International Conference on Plasma Science, 1999
Summary form only given. High pressure nonthermal plasmas are gaining increasing importance becau... more Summary form only given. High pressure nonthermal plasmas are gaining increasing importance because of their wide range of applications, e.g. in air plasma ramparts, gas processing, surface treatment, thin film deposition, and chemical and biological decontamination. In order to compare various methods of plasma generation with respect to efficiency, development of instabilities, homogeneity, lifetime etc., a central test facility for
Bookmarks Related papers MentionsView impact
Bioelectrochemistry, 2015
We tested if picosecond electric pulses (psEP; 190kV/cm, 500ps at 50% height), which are much sho... more We tested if picosecond electric pulses (psEP; 190kV/cm, 500ps at 50% height), which are much shorter than channel activation time, can activate voltage-gated (VG) channels. Cytosolic Ca(2+) was monitored by Fura-2 ratiometric imaging in GH3 and NG108 cells (which express multiple types of VG calcium channels, VGCC), and in CHO cells (which express no VGCC). Trains of up to 100psEP at 1kHz elicited no response in CHO cells. However, even a single psEP significantly increased Ca(2+) in both GH3 (by 114±48nM) and NG108 cells (by 6±1.1nM). Trains of 100psEP amplified the response to 379±33nM and 719±315nM, respectively. Ca(2+) responses peaked within 2-15s and recovered for over 100s; they were 80-100% inhibited by verapamil and ω-conotoxin, but not by the substitution of Na(+) with N-methyl-D-glucamine. There was no response to psEP in Ca(2+)-free medium, but adding external Ca(2+) even 10s later evoked Ca(2+) response. We conclude that electrical stimuli as short as 500ps can cause long-lasting opening of VGCC by a mechanism which does not involve conventional electroporation, heating (which was under 0.06K per psEP), or membrane depolarization by opening of VG Na(+) channels.
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For real-time imaging of the transmembrane voltage of Jurkat cells, exposed to nanosecond pulsed ... more For real-time imaging of the transmembrane voltage of Jurkat cells, exposed to nanosecond pulsed electric fields, the cells were stained with a voltage sensitive membrane dye (VSD) and illuminated with a 4.8 ns long dye-laser pulse at various time during the electric field pulse. The stained cells were located in a 100 mum stainless steel electrode arrangement mounted at the stage of an inverted microscope. Due to the weak fluorescence response from the membrane an intensified CCD camera was used for image acquisition. The camera was operated in an open-shutter mode. ANNINE-6, a recently developed ultra-fast VSD, and Di-8-ANEPPS were used for transient membrane voltage monitoring. Best results could be achieved with the ANNINE-6 dye. First results indicate a clear response of the VSDs attached to the membrane in case of exposing the cells to a 60 ns long electric field pulse
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2008 IEEE 35th International Conference on Plasma Science, 2008
In order to investigate the conditions for the induction of all physiological responses, the chan... more In order to investigate the conditions for the induction of all physiological responses, the changes of the transmembrane potential is recorded during the application of a nanosecond pulsed electric field in real time, i.e., with a temporal resolution of 5 ns, short compared to the duration of the pulse. Results show that the intense fast-rising pulses lead to an immediate
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Annual Report Conference on Electrical Insulation and Dielectric Phenomena, 2002
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2010 IEEE International Power Modulator and High Voltage Conference, 2010
The prolate spheroidal reflector antenna focuses pulsed radiation in the near field with a small ... more The prolate spheroidal reflector antenna focuses pulsed radiation in the near field with a small beam-width, allowing for applications such as target detection. We have investigated the use of two identical antennas for signal transmitting and receiving to detect a moving target behind obstacles, such as human movement behind a wall. The coverage area was found to be 10 m
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PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference. Digest of Papers (Cat. No.01CH37251), 2001
Abstract Nanosecond pulse generators, which provide kilovolt pulses, are required for application... more Abstract Nanosecond pulse generators, which provide kilovolt pulses, are required for applications such as pulsed lasers, electro-optical devices, electron heating of plasmas, and bioelectrics. Switches used to generate such short pulses include high-pressure spark gaps, ...
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Conference Record of the 2000 Twenty-fourth International Power Modulator Symposium, 2000
Intracellular electromanipulation (ICEM), the manipulation of substructures of biological cells b... more Intracellular electromanipulation (ICEM), the manipulation of substructures of biological cells by means of externally applied electric fields requires electrical pulses of nanosecond to tens of nanosecond duration and amplitudes of tens of kilovolt. The load in these bioelectric experiments, a cuvette containing biological cells, immersed in a solution of high conductivity, is generally on the order of 10 Ω. Strip
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2009 IEEE Pulsed Power Conference, 2009
The initial response of a cell to an applied electric field is determined by its dielectric prope... more The initial response of a cell to an applied electric field is determined by its dielectric properties. Conversely, exposure to an electric field can alter these parameters. Hence, an understanding of dielectric membrane phenomena helps in explaining the underlying interaction mechanisms. Moreover, different electrical characteristics might also allow devising exposure conditions for pulsed electric field treatments that can preferentially target
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2009 IEEE Pulsed Power Conference, 2009
... After the scattered signal is col-lected, an inverse scattering method can be used to recon-s... more ... After the scattered signal is col-lected, an inverse scattering method can be used to recon-struct the dielectric profile of the tissue. II. RESOLUTION The resolution of the imaging system using microwave radiation is determined by the wavelength. ... [7] A. Serhat et al, ???Focal ...
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30th Plasmadynamic and Lasers Conference, 1999
The temperature of the neutral particles in weakly ionized air can be determined by measuring the... more The temperature of the neutral particles in weakly ionized air can be determined by measuring the rotational spectrum of the 0-0 band within the second positive system of nitrogen and comparing it with simulated spectra. This diagnostic technique has been applied to direct current ...
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Electrical breakdown and recovery processes in water have been studied using electrical and nanos... more Electrical breakdown and recovery processes in water have been studied using electrical and nanosecond optical diagnostics. The breakdown electric field in submillimeter gaps with 200 ns voltage pulses applied has been measured as 1 MV/cm, the rate of current rise during breakdown reaches 4.1011 A/s. The switch recovery time is determined by expansion and decay of a vapor bubble. The experimental results, together with the results of a model with a percolative approach, provide design criteria for compact, high power, high repetition rate, liquid-switch pulse generators.
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Biochemical and Biophysical Research Communications, 2007
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Biochemical and Biophysical Research Communications, 2007
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Bioelectrochemistry, 2015
The presence of increased temperature for gene electrotransfer has largely been considered negati... more The presence of increased temperature for gene electrotransfer has largely been considered negative. Many reports have published on the lack of heat from electrotransfer conditions to demonstrate that their effects are from the electrical pulses and not from a rise in temperature. Our hypothesis was to use low levels of maintained heat from an exogenous source to aid in gene electrotransfer. The goal was to increase gene expression and/or reduce electric field. In our study we evaluated high and low electric field conditions from 90V to 45V which had been preheated to 40°C, 43°C, or 45°C. Control groups of non-heated as well as DNA only were included for comparison in all experiments. Luciferase gene expression, viability, and percent cell distribution were measured. Our results indicated a 2-4 fold increase in gene expression that is temperature and field dependent. In addition levels of gene expression can be increased without significant decreases in cell death and in the case of high electric fields no additional cell death. Finally, in all conditions percent cell distribution was increased from the application of heat. From these results, we conclude that various methods may be employed depending on the end user's desired goals. Electric field can be reduced 20-30% while maintaining or slightly increasing gene expression and increasing viability or overall gene expression and percent cell distribution can be increased with low viability.
Bookmarks Related papers MentionsView impact
31st Plasmadynamics and Lasers Conference, 2000
Bookmarks Related papers MentionsView impact
2014 IEEE 41st International Conference on Plasma Sciences (ICOPS) held with 2014 IEEE International Conference on High-Power Particle Beams (BEAMS), 2014
Bookmarks Related papers MentionsView impact
IEEE Transactions on Plasma Science, 2002
IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 ... Nanosecond Pulsed Electric... more IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 ... Nanosecond Pulsed Electric Field (nsPEF) Effects on ... Cells and Tissues: Apoptosis Induction and Tumor ... Stephen J. Beebe, Member, IEEE, PM Fox, LJ Rec, K. Somers, Robert H. Stark, ...
Bookmarks Related papers MentionsView impact
Applied Physics Letters, 1999
Bookmarks Related papers MentionsView impact
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2004
Electrical models for biological cells predict that reducing the duration of applied electrical p... more Electrical models for biological cells predict that reducing the duration of applied electrical pulses to values below the charging time of the outer membrane causes a strong increase in the probability for electric field interactions with intracellular structures. For electric field amplitudes exceeding MV/m such pulses are expected to cause electroporation of cell organelles, with the required electric field amplitude scaling linearly with the inverse of pulse duration. Experimental studies where human cells were exposed to pulsed electric field of up to 300 kV/cm amplitude with duration as short as 10 ns, have confirmed this hypothesis. The observed effects include the breaching of intracellular granule membranes without permanent damage to the cell membrane, abrupt rises in intracellular free calcium levels, and enhanced expression of genes. At increased electric fields, the application of nanosecond pulses induces apoptosis in biological cells, an effect that has been shown to ...
Bookmarks Related papers MentionsView impact
IEEE International Conference on Plasma Science, 1999
Summary form only given. High pressure nonthermal plasmas are gaining increasing importance becau... more Summary form only given. High pressure nonthermal plasmas are gaining increasing importance because of their wide range of applications, e.g. in air plasma ramparts, gas processing, surface treatment, thin film deposition, and chemical and biological decontamination. In order to compare various methods of plasma generation with respect to efficiency, development of instabilities, homogeneity, lifetime etc., a central test facility for
Bookmarks Related papers MentionsView impact
Bioelectrochemistry, 2015
We tested if picosecond electric pulses (psEP; 190kV/cm, 500ps at 50% height), which are much sho... more We tested if picosecond electric pulses (psEP; 190kV/cm, 500ps at 50% height), which are much shorter than channel activation time, can activate voltage-gated (VG) channels. Cytosolic Ca(2+) was monitored by Fura-2 ratiometric imaging in GH3 and NG108 cells (which express multiple types of VG calcium channels, VGCC), and in CHO cells (which express no VGCC). Trains of up to 100psEP at 1kHz elicited no response in CHO cells. However, even a single psEP significantly increased Ca(2+) in both GH3 (by 114±48nM) and NG108 cells (by 6±1.1nM). Trains of 100psEP amplified the response to 379±33nM and 719±315nM, respectively. Ca(2+) responses peaked within 2-15s and recovered for over 100s; they were 80-100% inhibited by verapamil and ω-conotoxin, but not by the substitution of Na(+) with N-methyl-D-glucamine. There was no response to psEP in Ca(2+)-free medium, but adding external Ca(2+) even 10s later evoked Ca(2+) response. We conclude that electrical stimuli as short as 500ps can cause long-lasting opening of VGCC by a mechanism which does not involve conventional electroporation, heating (which was under 0.06K per psEP), or membrane depolarization by opening of VG Na(+) channels.
Bookmarks Related papers MentionsView impact
For real-time imaging of the transmembrane voltage of Jurkat cells, exposed to nanosecond pulsed ... more For real-time imaging of the transmembrane voltage of Jurkat cells, exposed to nanosecond pulsed electric fields, the cells were stained with a voltage sensitive membrane dye (VSD) and illuminated with a 4.8 ns long dye-laser pulse at various time during the electric field pulse. The stained cells were located in a 100 mum stainless steel electrode arrangement mounted at the stage of an inverted microscope. Due to the weak fluorescence response from the membrane an intensified CCD camera was used for image acquisition. The camera was operated in an open-shutter mode. ANNINE-6, a recently developed ultra-fast VSD, and Di-8-ANEPPS were used for transient membrane voltage monitoring. Best results could be achieved with the ANNINE-6 dye. First results indicate a clear response of the VSDs attached to the membrane in case of exposing the cells to a 60 ns long electric field pulse
Bookmarks Related papers MentionsView impact
2008 IEEE 35th International Conference on Plasma Science, 2008
In order to investigate the conditions for the induction of all physiological responses, the chan... more In order to investigate the conditions for the induction of all physiological responses, the changes of the transmembrane potential is recorded during the application of a nanosecond pulsed electric field in real time, i.e., with a temporal resolution of 5 ns, short compared to the duration of the pulse. Results show that the intense fast-rising pulses lead to an immediate
Bookmarks Related papers MentionsView impact
Annual Report Conference on Electrical Insulation and Dielectric Phenomena, 2002
Bookmarks Related papers MentionsView impact
2010 IEEE International Power Modulator and High Voltage Conference, 2010
The prolate spheroidal reflector antenna focuses pulsed radiation in the near field with a small ... more The prolate spheroidal reflector antenna focuses pulsed radiation in the near field with a small beam-width, allowing for applications such as target detection. We have investigated the use of two identical antennas for signal transmitting and receiving to detect a moving target behind obstacles, such as human movement behind a wall. The coverage area was found to be 10 m
Bookmarks Related papers MentionsView impact
PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference. Digest of Papers (Cat. No.01CH37251), 2001
Abstract Nanosecond pulse generators, which provide kilovolt pulses, are required for application... more Abstract Nanosecond pulse generators, which provide kilovolt pulses, are required for applications such as pulsed lasers, electro-optical devices, electron heating of plasmas, and bioelectrics. Switches used to generate such short pulses include high-pressure spark gaps, ...
Bookmarks Related papers MentionsView impact
Conference Record of the 2000 Twenty-fourth International Power Modulator Symposium, 2000
Intracellular electromanipulation (ICEM), the manipulation of substructures of biological cells b... more Intracellular electromanipulation (ICEM), the manipulation of substructures of biological cells by means of externally applied electric fields requires electrical pulses of nanosecond to tens of nanosecond duration and amplitudes of tens of kilovolt. The load in these bioelectric experiments, a cuvette containing biological cells, immersed in a solution of high conductivity, is generally on the order of 10 Ω. Strip
Bookmarks Related papers MentionsView impact
2009 IEEE Pulsed Power Conference, 2009
The initial response of a cell to an applied electric field is determined by its dielectric prope... more The initial response of a cell to an applied electric field is determined by its dielectric properties. Conversely, exposure to an electric field can alter these parameters. Hence, an understanding of dielectric membrane phenomena helps in explaining the underlying interaction mechanisms. Moreover, different electrical characteristics might also allow devising exposure conditions for pulsed electric field treatments that can preferentially target
Bookmarks Related papers MentionsView impact
2009 IEEE Pulsed Power Conference, 2009
... After the scattered signal is col-lected, an inverse scattering method can be used to recon-s... more ... After the scattered signal is col-lected, an inverse scattering method can be used to recon-struct the dielectric profile of the tissue. II. RESOLUTION The resolution of the imaging system using microwave radiation is determined by the wavelength. ... [7] A. Serhat et al, ???Focal ...
Bookmarks Related papers MentionsView impact
30th Plasmadynamic and Lasers Conference, 1999
The temperature of the neutral particles in weakly ionized air can be determined by measuring the... more The temperature of the neutral particles in weakly ionized air can be determined by measuring the rotational spectrum of the 0-0 band within the second positive system of nitrogen and comparing it with simulated spectra. This diagnostic technique has been applied to direct current ...
Bookmarks Related papers MentionsView impact
Electrical breakdown and recovery processes in water have been studied using electrical and nanos... more Electrical breakdown and recovery processes in water have been studied using electrical and nanosecond optical diagnostics. The breakdown electric field in submillimeter gaps with 200 ns voltage pulses applied has been measured as 1 MV/cm, the rate of current rise during breakdown reaches 4.1011 A/s. The switch recovery time is determined by expansion and decay of a vapor bubble. The experimental results, together with the results of a model with a percolative approach, provide design criteria for compact, high power, high repetition rate, liquid-switch pulse generators.
Bookmarks Related papers MentionsView impact