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- Action potential; Body surface potential mapping; Electrocardiography; Forward problem; Ionic currents; Transmembrane potential; Vector (1)
- Apoptosis; gold nanorods; mitochondria damage; necrosis; photothermolysis; primary activated macrophages; two-photon luminescence imaging (1)
- Basic life support (BLS); Cardiopulmonary resuscitation (CPR); Coronary perfusion pressure; External chest compression (ECC); Mathematical model (1)
- Blood flow (1)
- Blood pressure (1)
Articles 1 - 5 of 5
Full-Text Articles in Engineering
Methods For Calculating Coronary Perfusion Pressure During Cpr, Michael P. Otlewski, Leslie A. Geddes, Michael Pargett, Charles F. Babbs
Methods For Calculating Coronary Perfusion Pressure During Cpr, Michael P. Otlewski, Leslie A. Geddes, Michael Pargett, Charles F. Babbs
Weldon School of Biomedical Engineering Faculty Publications
Coronary perfusion pressure (CPP) is a major indicator of the effectiveness of cardiopulmonary resuscitation in human and animal research studies; however methods for calculating CPP differ among research groups. Here we compare the 6 published methods for calculating CPP using the same data set of aortic (Ao) and right atrial (RA) blood pressures. CPP was computed using each of the 6 calculation methods in an anesthetized pig model, instrumented with catheters with Cobe pressure transducers. Aortic and right atrial pressures were recorded continuously during electrically induced ventricular fibrillation and standard CPR. CPP calculated from the same raw data set by …
Gold Nanorod-Mediated Photothermolysis Induces Apoptosis Of Macrophages Via Damage Of Mitochondria, Ling Tong, Ji-Xin Cheng
Gold Nanorod-Mediated Photothermolysis Induces Apoptosis Of Macrophages Via Damage Of Mitochondria, Ling Tong, Ji-Xin Cheng
Other Nanotechnology Publications
Aims: Induction of apoptosis or necrosis in activated macrophages by gold nanorod-mediated photothermolysis is demonstrated and the mechanisms underlying the processes are investigated. Materials & methods: Gold nanorods were functionalized with cysteine-octaarginine peptides (R8-NRs). Uptake of R8-NRs by activated macrophages was monitored by two-photon luminescence imaging. The laser irradiation conditions were controlled to induce apoptosis or necrosis to R8-NR-internalized macrophages. Mitochondrial damage and reactive oxygen species overproduction during photothermolysis was investigated by confocal fluorescence microscopy and transmission-electron microscopy. Results: Activated macrophages efficiently uptake R8-NRs both in vitro and in live animals. Laser irradiation of internalized nanorods with controlled power density …
Neonatal Cpr: Room At The Top—A Mathematical Study Of Optimal Chest Compression Frequency Versus Body Size, Charles F. Babbs, Andrew Meyer, Vinay Nadkarni
Neonatal Cpr: Room At The Top—A Mathematical Study Of Optimal Chest Compression Frequency Versus Body Size, Charles F. Babbs, Andrew Meyer, Vinay Nadkarni
Weldon School of Biomedical Engineering Faculty Publications
Objective: To explore in detail the expected magnitude of systemic perfusion pressure during standard CPR as a function of compression frequency for different sized people from neonate to adult. Method: A 7-compartment mathematical model of the human cardiopulmonary system—upgraded to include inertance of blood columns in the aorta and vena cavae—was exercised with parameters scaled to reflect changes in body weight from 1 to 70 kg. Results: Maximal systemic perfusion pressure occurs at chest compression rates near 60, 120, 180, and 250 per minute for subjects weighing 70, 10, 3, and 1 kg, respectively. Such maxima are predicted by analytical …
Quantitative Prediction Of Body Surface Potentials From Myocardial Action Potentials Using A Summed Dipole Model, Charles F. Babbs
Quantitative Prediction Of Body Surface Potentials From Myocardial Action Potentials Using A Summed Dipole Model, Charles F. Babbs
Weldon School of Biomedical Engineering Faculty Publications
This paper demonstrates quantitatively, using streamlined mathematics, how the transmembrane ionic currents in individual cardiac muscle cells act to produce the body surface potentials of the electrocardiogram (ECG). From fundamental principles of electrostatics, anatomy, and physiology, one can characterize the strength of apparent dipoles along a wavefront of depolarization in a local volume of myocardium. Net transmembrane flow of ionic current in actively depolarizing or repolarizing tissue induces extracellular current flow, which sets up a field of electrical potential that resembles that of a dipole. The local dipole strength depends upon the tissue cross section, the tissue resistivity, the resting …
Gold Nanorods As Contrast Agents For Biological Imaging: Optical Properties, Surface Conjugation And Photothermal Effects, Ling Tong, Qingshan Wei, Alexander Wei, Ji-Xin Cheng
Gold Nanorods As Contrast Agents For Biological Imaging: Optical Properties, Surface Conjugation And Photothermal Effects, Ling Tong, Qingshan Wei, Alexander Wei, Ji-Xin Cheng
Other Nanotechnology Publications
Gold nanorods (NRs) have plasmon-resonant absorption and scattering in the near-infrared (NIR) region, making them attractive probes for in vitro and in vivo imaging. In the cellular environment, NRs can provide scattering contrast for darkfield microscopy, or emit a strong two-photon luminescence due to plasmon-enhanced two-photon absorption. NRs have also been employed in biomedical imaging modalities such as optical coherence tomography or photoacoustic tomography. Careful control over surface chemistry enhances the capacity of NRs as biological imaging agents by enabling cell-specific targeting, and by increasing their dispersion stability and circulation lifetimes. NRs can also efficiently convert optical energy into heat, …