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You searched for subject:(Resistive pulse analysis). Showing records 1 – 3 of 3 total matches.

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University of Akron

1. Ni, Liwei. Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection.

Degree: PhD, Mechanical Engineering, 2020, University of Akron

Electrical properties of cells have been studied to understand the functions and mechanisms of various types of cells. The cell’s overall electricity results from the charged components present on the cell surface and the exchange of ions caused by cell electrical activities. It plays a crucial role in regulating various cell functions, and influences lots of important cellular events such as cell adhesion, cell migration, cell proliferation, cellular uptake, cell-cell communication, signal transduction, and protein trafficking.Certain types of cells can generate electrical signals through electrical activities, which are crucial to the functions of cardiac and nervous system. These signals can be evoked by certain electrical stimulations (ES). Recently, ES has shown the ability to regulate cell behaviours, and has been used in clinical treatments and helped the development of a variety of electro-bioreactor for tissue-engineering applications. A device with the ability to apply electrical stimulation precisely on cells and record the cell responses simultaneously is in great demand.To address the urgent demands, microfluidic devices that can quickly apply versatile electrical stimulation signals to cells in microfluidic channels and measure extracellular field potential simultaneously were developed in this thesis. Different structures were designed to measure the cell clusters and the single cells suspended in the fluidic environment. Cells can be collected for further analysis after the electric stimulation and field potential recording. Human cardiomyocytes and primary rat cortex neurons were tested with specific ES with the device. Results have shown that after applying specific ES on the excitable cell clusters and single cells, the cells evoked electrical responses. The devices have shown the ability to be able to noninvasively distinguish electrically excitable cells from electrically non-excitable cells. Application of variable ES signals on various excitable cells has shown that the application of ES clearly boosted cell electrical activities according to the stimulation frequency. Results demonstrated that the microfluidic devices could be used as tools to optimize ES conditions to facilitate the functional engineered cardiac tissue development and study the biological process of various types of cells.Another important cell electricity property is the cell surface charge. The charged components on the cell surface contributes to the cell surface charge. The cell surface charge has been recognized as an important indicator for cell properties. A microfluidic sensor based on resistive pulse sensing was developed in this thesis to assess surface charge sizes of single cells suspended in a continuous flow. The device consists of two consecutive resistive pulse sensors (RPSs) with identical dimensions. Opposite electric fields were applied on the two RPSs. A cell with a surface charge in the RPSs was accelerated or decelerated by the electric fields and thus exhibited different transit times passing through… Advisors/Committee Members: Zhe, Jiang (Advisor).

Subjects/Keywords: Biomedical Engineering; Mechanical Engineering; Microfluidic device, Cell analysis, Electrical stimulation, Extracellular field potential, Surface Charge, Resistive Pulse Sensing

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APA (6th Edition):

Ni, L. (2020). Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection. (Doctoral Dissertation). University of Akron. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=akron1586518282134534

Chicago Manual of Style (16th Edition):

Ni, Liwei. “Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection.” 2020. Doctoral Dissertation, University of Akron. Accessed October 22, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1586518282134534.

MLA Handbook (7th Edition):

Ni, Liwei. “Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection.” 2020. Web. 22 Oct 2020.

Vancouver:

Ni L. Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection. [Internet] [Doctoral dissertation]. University of Akron; 2020. [cited 2020 Oct 22]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1586518282134534.

Council of Science Editors:

Ni L. Microfluidic Device for Noninvasive Cell Electrical Stimulation, Extracellular Field Potential Analysis and Surface Charge Detection. [Doctoral Dissertation]. University of Akron; 2020. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1586518282134534


University of Arkansas

2. Rollings, Ryan Connor. The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis.

Degree: PhD, 2013, University of Arkansas

In this dissertation, the relationship between the geometry of ion-beam sculpted solid-state nanopores and their ability to analyze single DNA molecules using resistive pulse sensing is investigated. To accomplish this, the three dimensional shape of the nanopore is determined using energy filtered and tomographic transmission electron microscopy. It is shown that this information enables the prediction of the ionic current passing through a voltage biased nanopore and improves the prediction of the magnitude of current drop signals when the nanopore interacts with single DNA molecules. The dimensional stability of nanopores in solution is monitored using this information and is improved by modifying the pore's fabrication procedure. Furthermore, the correlation between noise sources present in the nanopore and the noble gas used to form the ion beam during fabrication is investigated. Finally, the polymerase chain reaction is used to verify that DNA translocates through ion-beam sculpted nanopores. Advisors/Committee Members: Jiali Li, Michael Lieber, David McNabb.

Subjects/Keywords: Pure sciences; Biological sciences; Applied sciences; DNA analysis; Ion beams; Nanopores; Noise sources; Resistive pulse sensing; Silicon nitride; Transmission electron microscopy; Biomedical; Biophysics; Biotechnology; Nanoscience and Nanotechnology; Optics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rollings, R. C. (2013). The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis. (Doctoral Dissertation). University of Arkansas. Retrieved from https://scholarworks.uark.edu/etd/727

Chicago Manual of Style (16th Edition):

Rollings, Ryan Connor. “The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis.” 2013. Doctoral Dissertation, University of Arkansas. Accessed October 22, 2020. https://scholarworks.uark.edu/etd/727.

MLA Handbook (7th Edition):

Rollings, Ryan Connor. “The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis.” 2013. Web. 22 Oct 2020.

Vancouver:

Rollings RC. The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis. [Internet] [Doctoral dissertation]. University of Arkansas; 2013. [cited 2020 Oct 22]. Available from: https://scholarworks.uark.edu/etd/727.

Council of Science Editors:

Rollings RC. The Geometry and Sensitivity of Ion-Beam Sculpted Nanopores for Single Molecule DNA Analysis. [Doctoral Dissertation]. University of Arkansas; 2013. Available from: https://scholarworks.uark.edu/etd/727

3. Lan, Wenjie. Particle transport and ion current rectification in conical-shaped nanopores.

Degree: PhD, Chemistry, 2011, University of Utah

This dissertation presents experimental and computational investigations of nanoparticle transport and ion current rectification in conical-shaped glass nanopore membranes (GNMs). Chapter 1 provides an overview of the Coulter counter or “resistive pulse” method, ion current rectification, and finite-element simulations used in solving mass transfer problems in conical-shaped nanopores. Chapter 2 describes a fundamental study of the electrophoretic translocation of charged polystyrene nanoparticles in conical-shaped pores contained within glass membranes using the Coulter counter principle, in which the time-dependent current is recorded as the nanoparticle is driven across the membrane. Particle translocation through the conical-shaped nanopore results in a direction-dependent and asymmetric triangularshaped resistive pulse. The simulation and xperimental results indicate that nanoparticle size can be differentiated based on pulse height. Chapter 3 presents experimental, theoretical, and finite-element simulation investigations of the pressure-driven translocation of nanoparticles across a conicalshaped GNM. Analytical theory and finite-element simulation for pressure-driven flow through a conical-shaped pore were developed to compute the volumetric flow rate, the position-dependent particle velocity, and the particle translocation frequency. The translocation frequencies computed from theory and simulation were found to be in agreement with experimental observations. Chapter 4 reports the pressure-dependent ion current rectification that occurs in conical-shaped glass nanopores in low ionic strength solutions. Because the pressureinduced flow rate is proportional to the third power of the nanopore orifice radius, the pressure-driven flow can eliminate rectification in nanopores with radii of ?200 nm but has a negligible influence on rectification in a nanopore with a radius of ?30 nm. The dependence of the i-V response on pressure is due to the dependence of cation and anion distributions on convective flow within the nanopore. Chapter 5 describes pressure-reversal methods to capture and release individual nanoparticles. One (or more) particle is driven through the orifice of a conical-shaped nanopore by pressure-induced flow. A reverse of flow, following the initial translocation, drives the particle back through the nanopore orifice in the opposite direction. The sequence of particle translocations in the capture step is preserved and can be read out in the release step. The observed instantaneous transfer rate and return probability are in good agreement with finite-element simulations of particle convection and diffusion in the confined geometry of the nanopore.

Subjects/Keywords: Capture and release; Coulter counter; Ion current rectification; Nanopores; Particle transport; Resistive pulse analysis

…The particle translocates through the pore at r generating a second resistive pulse and… …Wallace Coulter in 1953, is also called a resistive-pulse counter or electrical sensing zone… …pulse that can be measured in the current-time recordings. The resistive pulses generated by… …synthetic nanopore membranes as resistive-pulse sensors for molecular and macromolecule analytes… …colloid by a resistive-pulse method.16 In a previous report, our group introduced a technique of… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Lan, W. (2011). Particle transport and ion current rectification in conical-shaped nanopores. (Doctoral Dissertation). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/120/rec/1807

Chicago Manual of Style (16th Edition):

Lan, Wenjie. “Particle transport and ion current rectification in conical-shaped nanopores.” 2011. Doctoral Dissertation, University of Utah. Accessed October 22, 2020. http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/120/rec/1807.

MLA Handbook (7th Edition):

Lan, Wenjie. “Particle transport and ion current rectification in conical-shaped nanopores.” 2011. Web. 22 Oct 2020.

Vancouver:

Lan W. Particle transport and ion current rectification in conical-shaped nanopores. [Internet] [Doctoral dissertation]. University of Utah; 2011. [cited 2020 Oct 22]. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/120/rec/1807.

Council of Science Editors:

Lan W. Particle transport and ion current rectification in conical-shaped nanopores. [Doctoral Dissertation]. University of Utah; 2011. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/120/rec/1807

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