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Full-Text Articles in Physics

Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez Jun 2019

Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez

Alonso Gutierrez

No abstract provided.

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Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez Jun 2019

Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez

Jaafar Bennouna

No abstract provided.

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Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez Jun 2019

Development And Long-Term Stability Of A Comprehensive Daily Qa Program For A Modern Pencil Beam Scanning (Pbs) Proton Therapy Delivery System, Suresh Rana, Jaafar Bennouna, Alonso Gutierrez

Suresh Rana

No abstract provided.

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Developing Hyperpolarized Silicon Particles For In Vivo Mri Targeting Of Ovarian Cancer, Nicholas Whiting, Jingzhe Hu, Niki M. Zacharias, Ganesh L. R. Lokesh, David E. Volk, David G. Menter, Rajesha Rupaimoole, Rebecca Previs, Anil K. Sood, Pratip Bhattacharya Aug 2016

Developing Hyperpolarized Silicon Particles For In Vivo Mri Targeting Of Ovarian Cancer, Nicholas Whiting, Jingzhe Hu, Niki M. Zacharias, Ganesh L. R. Lokesh, David E. Volk, David G. Menter, Rajesha Rupaimoole, Rebecca Previs, Anil K. Sood, Pratip Bhattacharya

Nicholas Whiting

Silicon-based nanoparticles are ideally suited for use as biomedical imaging agents due to their biocompatibility, biodegradability, and simple surface chemistry that facilitates drug loading and targeting. A method of hyperpolarizing silicon particles using dynamic nuclear polarization, which increases magnetic resonance imaging signals by several orders-of-magnitude through enhanced nuclear spin alignment, has recently been developed to allow silicon particles to function as contrast agents for in vivo magnetic resonance imaging. The enhanced spin polarization of silicon lasts significantly longer than other hyperpolarized agents (tens of minutes, whereas <1  min for other species at room temperature), allowing a wide range of potential …

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Real-Time Mri-Guided Catheter Tracking Using Hyperpolarized Silicon Particles, Nicholas Whiting, Jingzhe Hu, Jay V. Shah, Maja C. Cassidy, Erik Cressman, Niki Zacharias Millward, David G. Menter, Charles M. Marcus, Pratip K. Bhattacharya Jan 2015

Real-Time Mri-Guided Catheter Tracking Using Hyperpolarized Silicon Particles, Nicholas Whiting, Jingzhe Hu, Jay V. Shah, Maja C. Cassidy, Erik Cressman, Niki Zacharias Millward, David G. Menter, Charles M. Marcus, Pratip K. Bhattacharya

Nicholas Whiting

Visualizing the movement of angiocatheters during endovascular interventions is typically accomplished using x-ray fluoroscopy. There are many potential advantages to developing magnetic resonance imaging-based approaches that will allow three-dimensional imaging of the tissue/vasculature interface while monitoring other physiologically-relevant criteria, without exposing the patient or clinician team to ionizing radiation. Here we introduce a proof-of-concept development of a magnetic resonance imaging-guided catheter tracking method that utilizes hyperpolarized silicon particles. The increased signal of the silicon particles is generated via low-temperature, solid-state dynamic nuclear polarization, and the particles retain their enhanced signal for ≥40 minutes—allowing imaging experiments over extended time durations. The …

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Hyperpolarization Methods For Mrs, Boyd M. Goodson, Nicholas Whiting, Aaron M. Coffey, Panayiotis Nikolaou, Fan Shi, Brogan M. Gust, Maxwell E. Gemeinhardt, Roman Shchepin, Jason G. Skinner, Jonathan R. Birchall, Michael J. Barlow, Eduard Y. Chekmenev Dec 2014

Hyperpolarization Methods For Mrs, Boyd M. Goodson, Nicholas Whiting, Aaron M. Coffey, Panayiotis Nikolaou, Fan Shi, Brogan M. Gust, Maxwell E. Gemeinhardt, Roman Shchepin, Jason G. Skinner, Jonathan R. Birchall, Michael J. Barlow, Eduard Y. Chekmenev

Nicholas Whiting

This article covers the fundamental principles and practice of NMR hyperpolarization techniques, which are proving useful for in vivo magnetic resonance spectroscopy (MRS) studies of metabolism in animal models, and clinical trials with hyper-enhanced sensitivity. Fundamentally, hyperpolarization methods enhance nuclear spin polarization by orders-of-magnitude, resulting in concomitant improvement in NMR detection sensitivity. The hyperpolarization methods described here – dynamic nuclear polarization (DNP), para-hydrogen induced polarization (PHIP), signal amplification by reversible exchange (SABRE), and spin-exchange optical pumping (SEOP) – are capable of achieving nuclear spin polarization approaching the theoretical maximum of unity on nuclear spin sites of molecular or atomic agents …

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Radiation Dose Distributions In Three Dimensions From Tomographic Optical Density Scanning Of Polymer Gels: Ii. Optical Properties Of The Bang Polymer Gel, Yevgeniya Zastavker, Marek Maryanski, John Gore Jun 2012

Radiation Dose Distributions In Three Dimensions From Tomographic Optical Density Scanning Of Polymer Gels: Ii. Optical Properties Of The Bang Polymer Gel, Yevgeniya Zastavker, Marek Maryanski, John Gore

Yevgeniya V. Zastavker

A newly developed method of radiation dosimetry makes use of the optical properties of polymer gels. The dose-response mechanism relies on the production of light-scattering polymer micro-particles in the gel at each site of radiation absorption. The scattering produces an attenuation of transmitted light intensity that is directly related to the dose and independent of dose rate. For the BANG polymer gel (bis, acrylamide, nitrogen, and gelatin) the shape of the dose-response curve depends on the fraction of the cross-linking monomer in the initial mixture and on the wavelength of light. At 500 nm the attenuation coefficient (μ) increases by …

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