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https://www.readbyqxmd.com/read/28543761/experimental-characterization-of-a-direct-conversion-amorphous-selenium-detector-with-thicker-conversion-layer-for-dual-energy-contrast-enhanced-breast-imaging
#1
David A Scadutom, Olivier Tousignant, Wei Zhao
PURPOSE: Dual-energy contrast-enhanced imaging is being investigated as a tool to identify and localize angiogenesis in the breast, a possible indicator of malignant tumors. This imaging technique requires that x-ray images are acquired at energies above the k-shell binding energy of an appropriate radiocontrast agent. Iodinated contrast agents are commonly used for vascular imaging, and require x-ray energies greater than 33 keV. Conventional direct conversion amorphous selenium (a-Se) flat panel imagers for digital mammography show suboptimal absorption efficiencies at these higher energies...
May 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28543739/sound-at-the-zoo-using-animal-monitoring-sound-measurement-and-noise-reduction-in-zoo-animal-management
#2
David A Orban, Joseph Soltis, Lori Perkins, Jill D Mellen
A clear need for evidence-based animal management in zoos and aquariums has been expressed by industry leaders. Here, we show how individual animal welfare monitoring can be combined with measurement of environmental conditions to inform science-based animal management decisions. Over the last several years, Disney's Animal Kingdom® has been undergoing significant construction and exhibit renovation, warranting institution-wide animal welfare monitoring. Animal care and science staff developed a model that tracked animal keepers' daily assessments of an animal's physical health, behavior, and responses to husbandry activity; these data were matched to different external stimuli and environmental conditions, including sound levels...
May 23, 2017: Zoo Biology
https://www.readbyqxmd.com/read/28540727/noiseless-performance-of-prussian-blue-based-bio-sensors-through-power-generation
#3
Maria A Komkova, Elena E Karyakina, Arkady A Karyakin
In contrast to 'self-powered' (bio)sensors aiming to generate maximum energy output, we propose the systems with the lowest potential difference between the working and the counter electrodes, which in galvanic mode would provide achievement of the best analytical performance characteristics. Prussian Blue based (bio)sensors known to operate at 0.00 V versus Ag|AgCl reference, in short-circuit regime generate the current proportional to analyte concentration. Sensitivity and dynamic range of Prussian Blue based (bio)sensors in power generation mode are, respectively, even slightly higher and wider compared to the same (bio)sensors operated in the conventional three-electrode regime powered by a potentiostat...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28538577/in-depth-review-of-symptoms-triggers-and-treatment-of-occipital-migraine-headaches-site-iv
#4
Mona Ascha, David E Kurlander, Abdus Sattar, James Gatherwright, Bahman Guyuron
BACKGROUND: This study reports the surgical technique and efficacy of deactivation of occipital-triggered migraine headaches. In addition, it reports the effect of surgical deactivation of occipital-triggered migraine headaches on migraine triggers and associated symptoms other than pain. METHODS: One hundred ninety-five patients undergoing surgery for occipital-triggered migraine headaches performed by a single surgeon, and followed for at least 1 year, were analyzed...
June 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28536713/calibration-transfer-of-near-infrared-spectroscopy-by-canonical-correlation-analysis-coupled-with-wavelet-transform
#5
Jun Bin, Xin Li, Wei Fan, Ji-Heng Zhou, Cheng-Wei Wang
Calibration model transfer has played a prominent role in the practical application of NIR spectral analysis. The change of instruments and sample physical states may lead to variation of the NIR spectrum, which results in the applicability of the model in judicatory practice being unsatisfactory. Therefore, a transfer for the calibration model considering both the variation of instruments and sample states is a necessity to ensure its availability. In this paper, a novel approach, namely canonical correlation analysis coupled with wavelet transform (WTCCA), was proposed for calibration transfer between two near infrared spectrometers (a portable and a laboratory instrument), and simultaneously, among three physical states (tobacco powder, tobacco filament and intact leaf) to determine the content of total sugars, reducing sugars, and nicotine in tobacco leaf samples, respectively...
May 24, 2017: Analyst
https://www.readbyqxmd.com/read/28534732/evaluation-of-adaptive-noise-management-technologies-for-school-age-children-with-hearing-loss
#6
Jace Wolfe, Mila Duke, Erin Schafer, Christine Jones, Lori Rakita
BACKGROUND: Children with hearing loss experience significant difficulty understanding speech in noisy and reverberant situations. Adaptive noise management technologies, such as fully adaptive directional microphones and digital noise reduction, have the potential to improve communication in noise for children with hearing aids. However, there are no published studies evaluating the potential benefits children receive from the use of adaptive noise management technologies in simulated real-world environments as well as in daily situations...
May 2017: Journal of the American Academy of Audiology
https://www.readbyqxmd.com/read/28533938/radionuclide-bone-scan-spect-ct-lowering-the-dose-of-ct-significantly-reduces-radiation-dose-without-impacting-ct-image-quality
#7
Sandeep Kumar Gupta, Scott Trethewey, Bree Brooker, Natalie Rutherford, Jenny Diffey, Suresh Viswanathan, John Attia
The CT component of SPECT-CT is required for attenuation correction and anatomical localization of the uptake on SPECT but there is no guideline about the optimal CT acquisition parameters. In our department, a standard CT acquisition protocol was changed in 2013 to give lower radiation dose to the patient. In this study, we retrospectively compared the effects on patient dose as well as the CT image quality with current versus older CT protocols. Ninety nine consecutive patients [n=51 Standard dose 'old' protocol (SDP); n=48 lower dose 'new' protocol (LDP)] with lumbar spine SPECT-CT for bone scan were examined...
2017: American Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/28528542/performance-of-a-high-pressure-liquid-chromatography-ion-mobility-mass-spectrometry-system-for-metabolic-profiling
#8
Xing Zhang, Kimberly Kew, Richard Reisdorph, Mark Sartain, Roger Powell, Michael L Armstrong, Kevin Quinn, Charmion Cruickshank-Quinn, Scott Walmsley, Samantha S Bokatzian, Ed Darland, Matthew Rain, Kenneth Imatani, Nichole Reisdorph
A commercial liquid chromatography/drift tube ion mobility-mass spectrometer (LC/IM-MS) was evaluated for its utility in global metabolomics analysis. Performance was assessed using twelve targeted metabolite standards where the limit of detection (LOD), linear dynamic range, resolving power, and collision cross section (Ω), is reported for each standard. Data was collected in three different instrument operation modes: flow injection analysis with IM-MS (FIA/IM-MS), LC/MS and LC/IM-MS. Metabolomics analyses of human plasma and HaCaT cells were used to compare the above three operation modes...
May 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28522170/optimization-of-the-alpha-image-reconstruction-an-iterative-ct-image-reconstruction-with-well-defined-image-quality-metrics
#9
Sergej Lebedev, Stefan Sawall, Michael Knaup, Marc Kachelrieß
PURPOSE: Optimization of the AIR-algorithm for improved convergence and performance. METHODS: The AIR method is an iterative algorithm for CT image reconstruction. As a result of its linearity with respect to the basis images, the AIR algorithm possesses well defined, regular image quality metrics, e.g. point spread function (PSF) or modulation transfer function (MTF), unlike other iterative reconstruction algorithms. The AIR algorithm computes weighting images α to blend between a set of basis images that preferably have mutually exclusive properties, e...
May 15, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28513211/image-quality-of-low-radiation-dose-left-atrial-ct-using-filtered-back-projection-and-an-iterative-reconstruction-algorithm-intra-individual-comparison-in-unselected-patients-undergoing-pulmonary-vein-isolation
#10
Ute Lina Fahlenkamp, Ivan Diaz Ramirez, Moritz Wagner, Carsten Schwenke, Alexander Huppertz, Bernd Hamm, Alexander Lembcke
Background Computed tomography (CT) of the left atrium (LA) is performed prior to pulmonary vein isolation (PVI) to improve success of circumferential ablation for atrial fibrillation. The ablation procedure itself exposes patients to substantial radiation doses, therefore radiation dose reduction in pre-ablational imaging is of concern. Purpose To assess and compare diagnostic performance of low-radiation dose preprocedural CT in patients scheduled for PVI using two types of reconstruction algorithms. Material and Methods Forty-six patients (61 ± 10 years) scheduled for PVI were enrolled in this study irrespective of body-mass-index or cardiac rhythm at examination...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28512363/-attenuation-of-earmuffs-used-simultaneously-with-respiratory-protective-devices
#11
Emil Kozłowski, Rafał Młyński
BACKGROUND: In the work environment, apart from the noise, employees may be exposed to other harmful factors. Therefore, they wear hearing protectors and other personal protective equipment. The aim of the study was to determine whether simultaneous use of earmuffs and respiratory protective devices affects the attenuation of earmuffs. MATERIAL AND METHODS: The study was conducted in laboratory conditions using the subjective REAT (Real Ear Attenuation at Threshold) and objective MIRE (Microphone in Real Ear) methods...
May 16, 2017: Medycyna Pracy
https://www.readbyqxmd.com/read/28510539/statistical-physics-approaches-to-subnetwork-dynamics-in-biochemical-systems
#12
Barbara Bravi, Peter Sollich
We apply a Gaussian variational approximation to model reduction in large biochemical networks of unary and binary reactions. We focus on a small subset of variables (subnetwork) of interest, e.g. because they are accessible experimentally, embedded in a larger network (bulk). The key goal is to write dynamical equations reduced to the subnetwork but still retaining the effects of the bulk. As a result, the subnetwork-reduced dynamics contains a memory term and an extrinsic noise term with non-trivial temporal correlations...
May 16, 2017: Physical Biology
https://www.readbyqxmd.com/read/28508438/the-effect-of-chronotherapy-on-delirium-in-critical-care%C3%A2-%C3%A2-a-systematic-review
#13
Roseanne Luther, Anne McLeod
BACKGROUND: Delirium is highly prevalent within critical care and is linked to adverse clinical outcomes, increased mortality and impaired quality of life. Development of delirium is thought to be caused by multiple risk factors, including disruption of the circadian rhythm. Chronotherapeutic interventions, such as light therapy, music and use of eye shades, have been suggested as an option to improve circadian rhythm within intensive care units. AIM: This review aims to answer the question: Can chronotherapy reduce the prevalence of delirium in adult patients in critical care? DESIGN: This study is a systematic review of quantitative studies...
May 15, 2017: Nursing in Critical Care
https://www.readbyqxmd.com/read/28506021/metal-artifact-reduction-in-spiral-fan-beam-ct-using-a-new-sinogram-segmentation-scheme
#14
Mehran Yazdi, Zohre Mansourian
Objective of this study is to present and test a new method for metal artifact reduction (MAR) by segmenting raw CT data (sinogram). The artifact suppression technique incorporates two steps namely, metal projection segmentation in the sinogram and replacement of segmented regions by new values using an interpolation method. The proposed segmentation algorithm uses the sinogram instead of reconstructed CT slices. First, one of the best and newest region-based geometric active contour models is used to detect projection data affected by metal objects (missing projections)...
May 6, 2017: Journal of X-ray Science and Technology
https://www.readbyqxmd.com/read/28505120/in-situ-raman-analysis-of-co%C3%A2-assisted-drying-of-fruit-slices
#15
Andreas Siegfried Braeuer, Julian Jonathan Schuster, Medhanie Tesfay Gebrekidan, Leo Bahr, Filippo Michelino, Alessandro Zambon, Sara Spilimbergo
This work explores the feasibility of applying in situ Raman spectroscopy for the online monitoring of the supercritical carbon dioxide (SC-CO₂) drying of fruits. Specifically, we investigate two types of fruits: mango and persimmon. The drying experiments were carried out inside an optical accessible vessel at 10 MPa and 313 K. The Raman spectra reveal: (i) the reduction of the water from the fruit slice and (ii) the change of the fruit matrix structure during the drying process. Two different Raman excitation wavelengths were compared: 532 nm and 785 nm...
May 15, 2017: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/28500985/low-dose-computed-tomography-pulmonary-angiography-protocol-for-imaging-pregnant-patients-can-dose-reduction-be-achieved-without-reducing-image-quality
#16
Darragh Halpenny, Brian Park, Jeffrey Alpert, Larry Latson, Nancy Kim, James Babb, Maria Shiau, Jane Ko
OBJECTIVE: To assess the effect of low dose computed tomography pulmonary angiography (CTPA) on radiation dose in pregnant patients. MATERIALS AND METHODS: An old CTPA protocol for pregnant patients was compared to a new protocol. Protocol changes included: decreased kVp; increased contrast injection rate; imaging after shallow inspiration. Patients undergoing CTPA before (phase 1 group) or after (phase 2 group) the protocol change, were assessed. RESULTS: Effective dose was lower in the phase 2 group (0...
April 7, 2017: Clinical Imaging
https://www.readbyqxmd.com/read/28497418/assessing-time-of-flight-signal-to-noise-ratio-gains-within-the-myocardium-and-subsequent-reductions-in-administered-activity-in-cardiac-pet-studies
#17
Ian S Armstrong, Christine M Tonge, Parthiban Arumugam
BACKGROUND: Time-of-flight (TOF) is known to increase signal-to-noise ratio (SNR) and facilitate reductions in administered activity. Established measures of SNR gain are derived from areas of uniform uptake, which is not applicable to the heterogeneous uptake in cardiac PET images using fluoro-deoxyglucose (FDG). This study aimed to develop a technique to quantify SNR gains within the myocardium due to TOF. METHODS: Reference TOF SNR gains were measured in 88 FDG oncology patients...
May 11, 2017: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/28488179/novel-contrast-injection-protocol-for-high-resolution-abdominal-ct-angiography-vascular-visualization-improvement-with-vasodilator
#18
Minori Hoshika, Kotaro Yasui, Takefumi Niguma, Toru Kojima, Norimi Nishiyama, Daisuke Suzuki, Izumi Togami
PURPOSE: To evaluate the usefulness of a novel contrast-injection protocol for high-resolution abdominal computed tomography angiography (CTA) using nitroglycerin (NTG). METHODS: Abdominal CTA was performed in 80 patients using two 64-detector-row CT scanners. Forty patients were examined after administration of sublingual NTG (NTG group), while 40 were examined without NTG administration (non-NTG group). Arterial phase images were acquired with maximum intensity projection and volume rendering...
May 9, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28487825/evaluation-of-whole-genome-amplified-dna-to-decrease-material-expenditure-and-increase-quality
#19
Marie Bækvad-Hansen, Jonas Bybjerg-Grauholm, Jesper B Poulsen, Christine S Hansen, David M Hougaard, Mads V Hollegaard
AIM: The overall aim of this study is to evaluate whole genome amplification of DNA extracted from dried blood spot samples. We wish to explore ways of optimizing the amplification process, while decreasing the amount of input material and inherently the cost. Our primary focus of optimization is on the amount of input material, the amplification reaction volume, the number of replicates and amplification time and temperature. Increasing the quality of the amplified DNA and the subsequent results of array genotyping is a secondary aim of this project...
June 2017: Molecular Genetics and Metabolism Reports
https://www.readbyqxmd.com/read/28487047/anodal-and-cathodal-electrical-stimulation-over-v5-improves-motion-perception-by-signal-enhancement-and-noise-reduction
#20
Luca Battaglini, Stefano Noventa, Clara Casco
BACKGROUND: The effect that transcranial direct current stimulation (tDCS) has on discrimination of coherent motion (CM) signals in a field of randomly moving dots (noise) can be accounted for by both noise reduction and signal enhancement. OBJECTIVE: To distinguish between noise reduction and signal enhancement, we monitored the discrimination of the correct CM direction as a function of the coherence level (using the psychophysical method of constant stimuli)...
April 28, 2017: Brain Stimulation
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