A5042768449- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Advanced MRI Techniques and Applications
- Advanced X-ray Imaging Techniques
- Radiomics and Machine Learning in Medical Imaging
- Laser-Plasma Interactions and Diagnostics
- Physics of Superconductivity and Magnetism
- Radiation Dose and Imaging
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Radiotherapy Techniques
- Anesthesia and Pain Management
- Electron and X-Ray Spectroscopy Techniques
- Radiation Detection and Scintillator Technologies
- Surface Roughness and Optical Measurements
- MRI in cancer diagnosis
- Laser-induced spectroscopy and plasma
- Spine and Intervertebral Disc Pathology
- Advanced Condensed Matter Physics
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Cardiac Imaging and Diagnostics
- Magnetic properties of thin films
- AI in cancer detection
- Medical Image Segmentation Techniques
- Chalcogenide Semiconductor Thin Films
St George's Hospital
2009-2024
SUNY Upstate Medical University
2014-2023
St George's Hospital
2011-2023
Lublin University of Technology
2022
St George’s University Hospitals NHS Foundation Trust
2016-2021
University of Silesia in Katowice
2015
Bellingham Technical College
2015
IBM (United States)
2014
University of Łódź
1977-2011
Syracuse University
1998-2010
Oxygen K-edge absorption spectra of carefully characterized ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_{4+\mathrm{\ensuremath{\delta}}}$ samples were measured using a bulk-sensitive fluoresence-yield-detection method. They reveal two distinct pre-edge peaks which evolve systematically as function Sr concentration. The are quantitatively described by calculations based on the Hubbard model, including local Coulomb interactions and core-hole...
Polarization-dependent x-ray-absorption spectroscopy on the O 1s and Cu 2p edges using non-surface-sensitive fluorescence method has been performed single crystals of ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_{4+\mathrm{\ensuremath{\delta}}}$, ${\mathit{R}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ce}}_{\mathit{x}}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ (R=Nd Sm), insulating compound...
Hard x-ray spectra (10–100 keV) created in high contrast, 400 fs, laser pulse interaction with solid targets, have been studied for intensities the 1017–1019 W/cm2 range. The target atomic numbers (Z) extended from Z=13 to Z=73. measured conversion efficiency at Ag Kα emission line was 10−3% 5×1018 W/cm2. It has confirmed that hot electron temperature increased as (Iλ2)1/3 and fraction of energy electrons follows scaling law (Iλ2)3/4.
We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate problem as constrained convex optimization with total variation (TV) regularization. then characterize solution of and show that it satisfies system fixed-point equations defined in terms two proximity operators raised from functions define TV-norm constraint involved The characterization (of...
The angular dependences of grazing-incidence x-ray scattering and Ge K\ensuremath{\alpha} fluorescence yield were measured for ${\mathrm{Si}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ge}}_{\mathit{x}}$/Si its inverted Si/${\mathrm{Si}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ge}}_{\mathit{x}}$ heterostructures. results reveal useful information on microstructures in these layered materials show similar interfacial structures terms the rms roughness, correlation length height...
An iterative algorithm is presented for accelerated reconstruction of cone beam transmission CT data (CBCT). CBCT supplies an attenuation map SPECT compensation and anatomical correlation. Iterative algorithms are necessary to reduce truncation artifacts 3D artifacts. existing maximum-likelihood (TRML) accurate but the time too long. The new a modified EM algorithm, based on ordered subsets (OSEM). OSEM was evaluated in comparison TRML using thorax phantom Defrise phantom. A wide range image...
A maximum-likelihood (ML) expectation-maximization (EM) algorithm (called EM-IntraSPECT) is presented for simultaneously estimating single photon emission computed tomography (SPECT) and attenuation parameters from data alone. The uses the activity within patient as transmission sources, with which coefficients can he estimated. For this initial study, EM-IntraSPECT was tested on computer-simulated maps representing a simplified human thorax well SPECT obtained physical phantom. Two...
Changes in various superconducting properties as a function of silver substitution the bulk granular high-Tc system Y-Ba-Cu-O have been investigated. In low doping limit, Ag impurities behave an excellent oxygen stabilizer and critical current density is enhanced by order magnitude while Tc remains practically unchanged. When content increased to above 20%, starts drop effects clusters well impurity phases become more important. However, compound still superconductor with around 20 K full...
Measurements of x-ray fluorescence versus grazing incidence angle at fixed incoming photon energy can provide useful information on surface and interfacial microstructure. A matrix formulation suitable for analysis radiant flow inside a layered material, hence angular emission, is presented, vector scattering model employed to account the effect roughness. Good agreement between experimental results yield calculations has been obtained in semiconductor heterostructure superlattice system.
The lifetimes of the excited states belonging to chiral partner bands built on πh11/2⊗νh11/2−1 configuration in 126Cs have been measured using DSA technique. For first time large set experimental transition probabilities is qualitative agreement with all selection rules predicted for strong symmetry breaking limit. originate from two general features a nucleus, namely, existence well separated left- and right-handed systems three angular momentum vectors extra symmetries appearing addition...
A laser‐produced plasma (LPP) x‐ray source with possible application in mammography was created by focusing a laser beam on Mo target. Table‐Top‐Terawatt (TTT) operating at 1 J energy per pulse employed. dual technique used. Maximum transfer from light to hot electrons reached 150 ps delay between pulses and the conversion efficiency (hard yield/laser input) The LPP is characterized very small focal spot size (tens of μm), Gaussian brightness distribution, short duration (a few ps). spectral...
We demonstrate the feasibility of phase-contrast imaging with an ultrafast laser-based hard x-ray source. Hard x rays are generated during interaction a high-intensity femtosecond laser pulse (10TW,60fs,10Hz) focused onto solid target in very small spot (3μm diam). Such novel source has number advantages over other sources previously used for imaging: It is compact and much cheaper than synchrotron, it higher power better spectrum control microfocal tube, repetition rate x-pinch The Kα line...
The 2D projection phase-contrast imaging performance of the ultrafast laser-based x-ray (ULX) source has been investigated. potential such a novel assessed by reference object (Contrast Detail Evaluation phantom) in in-line holography geometry and applying simple 1D numerical model to data analysis. results indicate that ULX is promising technique for implementation micro-Computed Tomography (μ-CT). This because using high contrast laser pulse simultaneously provides very small size along...
Interaction of intense Ti:sapphire laser with solid targets has been studied experimentally by measuring hard x-ray and hot electron generation. Hard (8–100 keV) emission spectrum Kα conversion efficiency (ηK) from plasma have as a function intensity (1017–1019 W/cm2), pulse duration (70–400)fs, fluence. For I>1×1017 W/cm2, the Ag ηK increases to reach maximum value 2×10−5 at an I=4×1018 W/cm2. Hot temperature (KTh) scaling laws parameters. A stronger dependence KTh fluence than on or...
The symmetry and density of unoccupied states twin-free ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{4}$${\mathrm{O}}_{8}$ single crystals have been investigated by orientation-dependent x-ray absorption spectroscopy at the O 1s edge, using a bulk-sensitive fluoresence-yield-detection method. In conjunction with earlier results obtained electron-energy-loss spectroscopy, relative for different oxygen sites has derived. Comparison local-density...
X-ray fluorescence and total electron yield around the oxygen K edge of high-${\mathit{T}}_{\mathit{c}}$ Y-Ba-Cu-O Bi-Sr-Ca-Cu-O superconductor films were measured. The spectra in these materials obtained by using a new parallel-plate avalanche detector high-resolution soft-x-ray spectrometer. Comparison results with other data indicates that method is free from spurious features caused contaminants oxygen-depletion layers, as usually found electron-spectroscopy measurements, meaningful...
Abstract A detailed study is made of the localized vibrational stretching modes hydrogen in GaAs using high‐energy proton implantation and low‐temperature Fourier transform infrared spectroscopy. New mode frequencies are found confirmed with help deuterium implantation. comparison proton‐ deuteron‐implanted germanium shows a different shape bands to GaAs. The oscillator strengths effective charges determined for observed.
Nerve damage after regional anesthesia has been of great concern to anesthetists. Various modalities have suggested recognize and prevent its incidence. An understudied area is the measurement intraneural pressure during peripheral nerve blockade. Previous investigations produced contradicting results with only one study being conducted on human cadavers.The purpose this investigation was systematically record perineural injection pressures median, ulnar, radial nerves exclusively as a...
Genicular nerve radiofrequency (RF)denervation appears to be a promising treatment for knee pain in patients with degenerative osteoarthritis of the knee, when candidates are not suitable arthroplasty. This study aimed assess accuracy and reliability ultrasound-guided placement RF cannulas cadavers genicular treatment, by measuringthe needle-to-nerve proximity.