37 results match your criteria AIP conference proceedings[Journal]

  • Page 1 of 1

Introducing Causality Violation for Improved DPOAE Component Unmixing.

AIP Conf Proc 2018 May;1965(1)

Caruso Department of Otolaryngology, Keck School of Medicine, University of Southern California, Los Angeles (CA), USA.

The DPOAE response consists of the linear superposition of two components, a nonlinear distortion component generated in the overlap region, and a reflection component generated by roughness in the DP resonant region. Due to approximate scaling symmetry, the DPOAE distortion component has approximately constant phase. As the reflection component may be considered as a SFOAE generated by the forward DP traveling wave, it has rapidly rotating phase, relative to that of its source, which is also equal to the phase of the DPOAE distortion component. Read More

View Article

Download full-text PDF

Source
http://aip.scitation.org/doi/abs/10.1063/1.5038497
Publisher Site
http://dx.doi.org/10.1063/1.5038497DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6078433PMC
May 2018
2 Reads

Probing Apical-Basal Differences in the Human Cochlea Using Distortion-Product Otoacoustic Emission Phase.

AIP Conf Proc 2018 May;1965(1)

Auditory Research Center, Caruso Department of Otolaryngology, Keck School of Medicine, University of Southern California, 1640 Marengo St, Los Angeles, CA 90033, USA.

Distortion-product otoacoustic emission (DPOAE) phase is shaped by interaction between the evoking stimulus waves. Near-invariant at high frequencies, DPOAE phase-vs-frequency functions measured at fixed ratios bend into sloping functions at low frequencies. The different phase behaviors observed suggest that the mechanics underlying the generation of OAEs differ in the halves of the cochlea. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5038495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6078425PMC

Temporal Suppression of Clicked-Evoked Otoacoustic Emissions and Basilar-Membrane Motion in Gerbils.

AIP Conf Proc 2018 31;1965(1). Epub 2018 May 31.

Caruso Department of Otolaryngology, University of Southern California, CA, USA.

Otoacoustic emissions evoked by a click (CEOAEs) can be reduced if the evoking sound is preceded or followed by another ("suppressor") click. Studying the temporal suppression of CEOAEs can provide insights into the dynamics of cochlear nonlinearity. However, temporal suppression has never been measured in basilar-membrane (BM) motion. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5038490DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6063374PMC

Passive Microlesion Detection and Mapping for Treatment of Hypertrophic Cardiomyopathy.

AIP Conf Proc 2017 1;1816(1). Epub 2017 Mar 1.

Department of Radiology, University of Michigan Medical Center, Ann Arbor, MI.

Intermittent high intensity ultrasound pulses with circulating contrast agent microbubbles can induce scattered microlesions of potential value for myocardial reduction therapy. This paper presents an setup imitating the treatment for monitoring development. A preclinical imaging system with a single element transducer, synchronization and receive-only imaging transducer array has been implemented on a research platform. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4976594DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5529597PMC
March 2017
1 Read

Advances and challenges in cryo ptychography at the Advanced Photon Source.

AIP Conf Proc 2016;1696

X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA; Department of Physics & Astronomy and Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA.

Ptychography has emerged as a nondestructive tool to quantitatively study extended samples at a high spatial resolution. In this manuscript, we report on recent developments from our team. We have combined cryo ptychography and fluorescence microscopy to provide simultaneous views of ultrastructure and elemental composition, we have developed multi-GPU parallel computation to speed up ptychographic reconstructions, and we have implemented fly-scan ptychography to allow for faster data acquisition. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4937524DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4898057PMC
January 2016

Increasing Computational Efficiency of Cochlear Models Using Boundary Layers.

AIP Conf Proc 2015 Dec;1703

Speech and Hearing Bioscience and Technology, Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA. Eaton-Peabody Laboratories, Harvard Medical School, Boston, Massachusetts, USA.

Our goal is to develop methods to improve the efficiency of computational models of the cochlea for applications that require the solution accurately only within a basal region of interest, specifically by decreasing the number of spatial sections needed for simulation of the problem with good accuracy. We design algebraic spatial and parametric transformations to computational models of the cochlea. These transformations are applied after the basal region of interest and allow for spatial preservation, driven by the natural characteristics of approximate spatial causality of cochlear models. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4939391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862608PMC
December 2015

Relating the Variability of Tone-Burst Otoacoustic Emission and Auditory Brainstem Response Latencies to the Underlying Cochlear Mechanics.

AIP Conf Proc 2015 Dec;1703

Eaton-Peabody Laboratories, Harvard Medical School, Boston, Massachusetts, USA.

Forward and reverse cochlear latency and its relation to the frequency tuning of the auditory filters can be assessed using tone bursts (TBs). Otoacoustic emissions (TBOAEs) estimate the cochlear roundtrip time, while auditory brainstem responses (ABRs) to the same stimuli aim at measuring the auditory filter buildup time. Latency ratios are generally close to two and controversy exists about the relationship of this ratio to cochlear mechanics. Read More

View Article

Download full-text PDF

Source
http://aip.scitation.org/doi/abs/10.1063/1.4939401
Publisher Site
http://dx.doi.org/10.1063/1.4939401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862599PMC
December 2015
2 Reads

Experimental Study of Acoustic Radiation Force of an Ultrasound Beam on Absorbing and Scattering Objects.

AIP Conf Proc 2015 Jun;1685

Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th St. Seattle WA 98105.

Acoustic radiation force is a nonlinear acoustic effect caused by the transfer of wave momentum to absorbing or scattering objects. This phenomenon is exploited in modern ultrasound metrology for measurement of the acoustic power radiated by a source and is used for both therapeutic and diagnostic sources in medical applications. To calculate radiation force an acoustic hologram can be used in conjunction with analytical expressions based on the angular spectrum of the measured field. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4934404DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852870PMC
June 2015
1 Read

Nonlinear Effects in Ultrasound Fields of Diagnostic-type Transducers Used for Kidney Stone Propulsion: Characterization in Water.

AIP Conf Proc 2015 Jun-Jul;1685. Epub 2015 Oct 28.

Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow, Russian Federation; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40 Street, Seattle, WA 98105, USA.

Newer imaging and therapeutic ultrasound technologies require higher pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4934397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831865PMC
October 2015
1 Read

Non-negative matrix analysis in x-ray spectromicroscopy: choosing regularizers.

AIP Conf Proc 2016 Jan;1696

X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, USA; Dept. Physics & Astronomy, Northwestern University, Evanston, Illinois, USA.

In x-ray spectromicroscopy, a set of images can be acquired across an absorption edge to reveal chemical speciation. We previously described the use of non-negative matrix approximation methods for improved classification and analysis of these types of data. We present here an approach to find appropriate values of regularization parameters for this optimization approach. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4937528DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4817849PMC
January 2016
1 Read

Hydrodynamic Radius Fluctuations in Model DNA-Grafted Nanoparticles.

AIP Conf Proc 2016 ;1736(1)

Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.

We utilize molecular dynamics simulations (MD) and the path-integration program ZENO to quantify hydrodynamic radius () fluctuations of spherical symmetric gold nanoparticles (NPs) decorated with single-stranded DNA chains (ssDNA). These results are relevant to understanding fluctuation-induced interactions among these NPs and macromolecules such as proteins. In particular, we explore the effect of varying the ssDNA-grafted NPs structural parameters, such as the chain length (), chain persistence length (), NP core size (), and the number of chains () attached to the nanoparticle core. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4949655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514619PMC
January 2016

Exploiting Dual Otoacoustic Emission Sources.

AIP Conf Proc 2015 ;1703

Department of Otolaryngology, Keck School of Medicine, University of Southern California Neuroscience Graduate Program, University of Southern California.

Two distinct processes generate otoacoustic emissions (OAEs). emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. Read More

View Article

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5042209PMC
http://dx.doi.org/10.1063/1.4939413DOI Listing
January 2015
2 Reads

Macromechanics of Hearing: The Unknown Known.

AIP Conf Proc 2014 Jun;1703

Eaton-Peabody Laboratories, Boston, Massachusetts, USA.

The following summarizes the key points addressed during a tutorial session on the Macromechanics of Hearing that took place at the 12 International Workshop on the Mechanics of Hearing held at Cape Sounio, Greece, in June 2014. The tutorial was intended to present an overview of basic ideas and to address topics of current interest relevant to the Workshop. The session was recorded, and the audio file and accompanying visual content of the presentation can be found in the Mechanics of Hearing Digital Library (www. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4939315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019571PMC

Overcoming Biological Barriers with Ultrasound.

AIP Conf Proc 2012 Jan;1481:381-387

Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.

Effect of ultrasound on the permeability of blood vessels and cell membranes to macromolecules and nanodroplets was investigated using mouse carotid arteries and tumor cells. Model macromolecular drug, FITC-dextran with molecular weight of 70,000 Da was used in experiments with carotid arteries. The effect of unfocused 1-MHz ultrasound and and perfluoro-15-crown-5-ether nanodroplets stabilized with the poly(ethylene oxide)-co-poly(D,L-lactide) block copolymer shells was studied. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4757365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4022599PMC
January 2012
1 Read

Tracing Distortion Product (DP) Waves in a Cochlear Model.

AIP Conf Proc 2011 Nov;1403(1):557-562

Hearing Research Center, Oregon Health and Science University.

In many cases a cochlear model suffices to explain (by simulation) the properties of waves in the cochlea. This is not so in the case of a distortion product (DP) set up by presenting two primary tones to the cochlea. A three-dimensional model predicts, apart from a DP wave traveling in the apical direction, a DP wave that travels from the region of overlap of the two tone patterns towards the stapes-setting the stapes in motion so as to produce an otoacoustic emission at the DP frequency. Read More

View Article

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181363PMC
November 2011
1 Read

Can a Static Nonlinearity Account for the Dynamics of Otoacoustic Emission Suppression?

AIP Conf Proc 2011 Nov;1403(1):257-263

Centre for Applied Hearing Research, Technical University of Denmark.

This study investigates whether time-dependent compression mechanisms in the cochlea are necessary to explain dynamic properties of otoacoustic emissions (OAEs). Dynamic properties of click-evoked OAEs (CEOAEs) have been observed in temporal suppression; the effect where the CEOAE magnitude is reduced when a click is presented less than 10 ms before the test click. A time-domain model of the cochlea that represented the basilar membrane (BM) as a cascade of coupled bandpass filters was used to investigate the cochlear origin of temporal suppression in CEOAEs. Read More

View Article

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181367PMC
November 2011

Parameter Estimation as a Problem in Statistical Thermodynamics.

AIP Conf Proc 2011 Mar;1305(1):357-364

Physics Department, University at Albany (SUNY), , http://earlelab.rit.albany.edu.

In this work, we explore the connections between parameter fitting and statistical thermodynamics using the maxent principle of Jaynes as a starting point. In particular, we show how signal averaging may be described by a suitable one particle partition function, modified for the case of a variable number of particles. These modifications lead to an entropy that is extensive in the number of measurements in the average. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3573638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170718PMC

A Multimodal Nanocomposite for Biomedical Imaging.

AIP Conf Proc 2011 Sep;1365:379

Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 USA ; Department of Radiology, Feinberg School of Medicine, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611 USA.

A multimodal nanocomposite was designed, synthesized with super-paramagnetic core (CoFeO), noble metal corona (Au), and semiconductor shell (TiO). The sizes of core, core-corona, and core-corona-shell particles were determined by TEM. This multimodal nanocrystal showed promise as a contrast agent for two of the most widely used biomedical imaging techniques: magnetic resonance imaging (MRI) and X-ray computed tomography (CT). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3625382DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4012782PMC
September 2011
12 Reads

Interrogation of EGFR Targeted Uptake of TiO Nanoconjugates by X-ray Fluorescence Microscopy.

AIP Conf Proc 2011 Sep;1365(423):423-426

Northwestern University, 303 E. Chicago Ave., Chicago IL, USA.

We are developing TiO nanoconjugates that can be used as therapeutic and diagnostic agents. Nanoscale TiO can be surface conjugated with various molecules and has the unique ability to induce the production of reactive oxygen species after radiation activation. One way to improve the potential clinical usefulness of TiO nanoparticles is to control their delivery to malignant cells by targeting them to cancer cell specific antigens. Read More

View Article

Download full-text PDF

Source
http://aip.scitation.org/doi/abs/10.1063/1.3625393
Publisher Site
http://dx.doi.org/10.1063/1.3625393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180943PMC
September 2011
1 Read

Towards Using Molecular States as Qubits.

AIP Conf Proc 2011 Sep;1384(1):251-253

Department of Chemistry, Indian Institute of Technology Kanpur Kanpur - 208016, INDIA.

Molecular systems are presented as possible qubit systems by exploring non-resonant molecular fragmentation of n-propyl benzene with femtosecond laser pulses as a model case. We show that such laser fragmentation process is dependent on the phase and polarization characteristics of the laser. The effect of the chirp and polarization of the femtosecond pulse when applied simultaneously is mutually independent of each other, which makes chirp and polarization as useful 'logic' implementing parameters for such molecular qubits. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3635869DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3695453PMC
September 2011
2 Reads

A Two-Magnet System to Push Therapeutic Nanoparticles.

AIP Conf Proc 2010 Dec;1311(1):77-88

Fischell Department of Bio-Engineering, Institute for Systems Research (ISR), 1226 Kim Building, University of Maryland, College Park, MD 20742.

Magnetic fields can be used to direct magnetically susceptible nanoparticles to disease locations: to infections, blood clots, or tumors. Any single magnet always attracts (pulls) ferro- or para-magnetic particles towards it. External magnets have been used to pull therapeutics into tumors near the skin in animals and human clinical trials. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3530064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3020086PMC
December 2010
1 Read

Control Of Screening Of A Charged Particle In Electrolytic Aqueous Paul Trap.

AIP Conf Proc 2011 ;1336:150-153

Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6372, USA.

Individual charged particles could be trapped and confined by the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3586077DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4022476PMC
January 2011

Otoacoustic Estimates of Cochlear Tuning: Testing Predictions in Macaque.

AIP Conf Proc 2011 ;1403:286-292

Laboratory of Auditory Neurophysiology, University of Leuven.

Otoacoustic estimates of cochlear frequency selectivity suggest substantially sharper tuning in humans. However, the logic and methodology underlying these estimates remain untested by direct measurements in primates. We report measurements of frequency tuning in macaque monkeys, Old-World primates phylogenetically closer to humans than the small laboratory animals often taken as models of human hearing (e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3658099DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3971997PMC
January 2011
31 Reads

Forward- and Reverse-Traveling Waves in DP Phenomenology: Does Inverted Direction of Wave Propagation Occur in Classical Models?

AIP Conf Proc 2011 ;1403

Department of Physics and Mathematics, University of Insubria.

Recent basilar-membrane (BM) vibration experiments show that the phase slope of the distortion product (DP) in the cochlear region in which a backward-traveling wave is expected is negative, which is typical of a forward-traveling wave, according to the predictions of quasi-linear approximate solutions of classical 1-D transmission-line cochlear models. This phase behavior has been interpreted as suggesting a strong deviation from the "classical" models of the otoacoustic emission (OAE) generation and transmission. In this paper, the DP phase inversion phenomenon is approached from a conservative point of view. Read More

View Article

Download full-text PDF

Source
http://aip.scitation.org/doi/abs/10.1063/1.3658153
Publisher Site
http://dx.doi.org/10.1063/1.3658153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873145PMC
January 2011
15 Reads

Deviations from Scaling Symmetry in the Apical Half of the Human Cochlea.

AIP Conf Proc 2011 7;1403:483-488. Epub 2011 Nov 7.

House Research Institute, Division of Communication & Auditory Neuroscience, 2100 W. 3rd St, Los Angeles, CA 90057, USA.

Invariant distortion product otoacoustic emission (DPOAE) phase elucidates scaling symmetry in the cochlea. Below some low-frequency boundary, DPOAE phase slope steepens. The origin of this break in phase invariance is not clear. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3658135DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3382980PMC
November 2011
3 Reads

Detecting Fleeting MRI Signals with Frequency-Modulated Pulses.

AIP Conf Proc 2011 29;1330:23-26. Epub 2011 Mar 29.

Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.

We describe a fundamentally different approach to MRI referred to as SWIFT (sweep imaging with Fourier transformation). SWIFT exploits time-shared RF excitation and signal acquisition, allowing capture of signal from spins with extremely short transverse relaxation time, T(2)*. The MR signal is acquired in gaps inserted into a broadband frequency-swept excitation pulse, which results in acquisition delays of only 1 - 2 microseconds. Read More

View Article

Download full-text PDF

Source
http://aip.scitation.org/doi/abs/10.1063/1.3562224
Publisher Site
http://dx.doi.org/10.1063/1.3562224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3363361PMC
March 2011
5 Reads

Hard X-ray Full Field Nano-imaging of Bone and Nanowires at SSRL.

AIP Conf Proc 2010 Jun;1234:79-82

Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laborator, 2575 Sand Hill Rd, Menlo Park CA 94025 USA.

A hard X-ray full field microscope from Xradia Inc. has been installed at SSRL on a 54-pole wiggler end station at beam line 6-2. It has been optimized to operate from 5-14 keV with resolution as high as 30 nm. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3463334DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2944249PMC
June 2010
1 Read

Introduction To Monte Carlo Simulation.

AIP Conf Proc 2010 Jan;1204:17-21

Department of Radiology, University of Washington Medical Center, 1959 Pacific NE - RR215, Box 357987, Seattle, Washington 98195, USA.

This paper reviews the history and principles of Monte Carlo simulation, emphasizing techniques commonly used in the simulation of medical imaging. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3295638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2924739PMC
January 2010
2 Reads

Monte Carlo Simulation Of Emission Tomography And Other Medical Imaging Techniques.

AIP Conf Proc 2010 Jan;1204:126-132

Department of Radiology, University of Washington Medical Center, Box 357987, 1959 Pacific NET - RR215, Seattle, Washington 98195, USA.

An introduction to Monte Carlo simulation of emission tomography. This paper reviews the history and principles of Monte Carlo simulation, then applies these principles to emission tomography using the public domain simulation package SimSET (a Simulation System for Emission Tomography) as an example. Finally, the paper discusses how the methods are modified for X-ray computed tomography and radiotherapy simulations. Read More

View Article

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2924737PMC
January 2010
3 Reads

Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

AIP Conf Proc 2010 Aug;1336:351-355

Center for Radiological Research, Columbia University 630 West 168th Street, 11th floor, New York, NY 10032.

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3586118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570827PMC
August 2010
1 Read

Magnetic Pressure as a Scalar Representation of Field Effects in Magnetic Suspensions.

AIP Conf Proc 2010 ;1311:111-117

Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, U.S.A.

Magnetic microsphere suspensions undergo complex motion when exposed to finite sources of the magnetic field, such as small permanent magnets. The computational complexity is compounded by a difficulty in choosing a suitable choice of visualization tools because this often requires using the magnetic force vector field in three dimensions. Here we present a potentially simpler approach by using the magnetic pressure. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3529999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224033PMC
January 2010
1 Read

Effective Dose from Stray Radiation for a Patient Receiving Proton Therapy for Liver Cancer.

AIP Conf Proc 2009 Mar;1099:445-449

The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Unit 94, Houston, TX 77030, USA.

Because of its advantageous depth-dose relationship, proton radiotherapy is an emerging treatment modality for patients with liver cancer. Although the proton dose distribution conforms to the target, healthy tissues throughout the body receive low doses of stray radiation, particularly neutrons that originate in the treatment unit or in the patient. The aim of this study was to calculate the effective dose from stray radiation and estimate the corresponding risk of second cancer fatality for a patient receiving proton beam therapy for liver cancer. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3120070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2943390PMC
March 2009
1 Read

Contemporary Proton Therapy Systems Adequately Protect Patients from Exposure to Stray Radiation.

AIP Conf Proc 2009 Mar;1099(1):450-455

Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Unit 94, Houston, TX 77030, USA.

Proton beam therapy has provided safe and effective treatments for a variety of adult cancers. In recent years, there has been increasing interest in utilizing proton therapy for pediatric cancers because it allows better sparing of healthy tissues. Minimizing exposures of normal tissues is especially important in children because they are highly susceptible to consequential late effects, including the development of a radiogenic second cancer, which may occur years or even decades after treatment of the first cancer. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.3120071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2939014PMC
March 2009
6 Reads

Using Helical CT to Predict Stone Fragility in Shock Wave Lithotripsy (SWL).

AIP Conf Proc 2007 5;900:326-339. Epub 2007 Apr 5.

Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.

Great variability exists in the response of urinary stones to SWL, and this is true even for stones composed of the same mineral. Efforts have been made to predict stone fragility to shock waves using computed tomography (CT) patient images, but most work to date has focused on the use of stone CT number (i.e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2723592DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5939597PMC

Flavin Charge Transfer Transitions Assist DNA Photolyase Electron Transfer.

AIP Conf Proc 2007 ;963:674-677

Department of Physics, University of Cyprus, PO Box 20537, Nicosia 1678, Cyprus.

This contribution describes molecular dynamics, semi-empirical and ab-initio studies of the primary photo-induced electron transfer reaction in DNA photolyase. DNA photolyases are FADH(-)-containing proteins that repair UV-damaged DNA by photo-induced electron transfer. A DNA photolyase recognizes and binds to cyclobutatne pyrimidine dimer lesions of DNA. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2836174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3514966PMC
January 2007

Automated image processing and analysis of cartilage MRI: enabling technology for data mining applied to osteoarthritis.

AIP Conf Proc 2007 ;953:262-276

Department of Biomedical Engineering, University of California, Los Angeles, 7523 Boelter Hall, Los Angeles, CA 90024 USA.

Osteoarthritis (OA) is a heterogeneous and multi-factorial disease characterized by the progressive loss of articular cartilage. Magnetic Resonance Imaging has been established as an accurate technique to assess cartilage damage through both cartilage morphology (volume and thickness) and cartilage water mobility (Spin-lattice relaxation, T2). The Osteoarthritis Initiative, OAI, is a large scale serial assessment of subjects at different stages of OA including those with pre-clinical symptoms. Read More

View Article

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140873PMC
January 2007
1 Read

Adiabatic Quantum Computation: Coherent Control Back Action.

AIP Conf Proc 2006 Nov;864:273-294

Department of Chemistry and the Center for Laser Technology Indian Institute of Technology, Kanpur - 208016, INDIA.

Though attractive from scalability aspects, optical approaches to quantum computing are highly prone to decoherence and rapid population loss due to nonradiative processes such as vibrational redistribution. We show that such effects can be reduced by adiabatic coherent control, in which quantum interference between multiple excitation pathways is used to cancel coupling to the unwanted, non-radiative channels. We focus on experimentally demonstrated adiabatic controlled population transfer experiments wherein the details on the coherence aspects are yet to be explored theoretically but are important for quantum computation. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2400899DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684796PMC
November 2006
1 Read
  • Page 1 of 1