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Imaging efficiency measures

Jing Qian, Sy Han Chiou, Jacqueline E Maye, Folefac Atem, Keith A Johnson, Rebecca A Betensky
In several common study designs, regression modeling is complicated by the presence of censored covariates. Examples of such covariates include maternal age of onset of dementia that may be right censored in an Alzheimer's amyloid imaging study of healthy subjects, metabolite measurements that are subject to limit of detection censoring in a case-control study of cardiovascular disease, and progressive biomarkers whose baseline values are of interest, but are measured post-baseline in longitudinal neuropsychological studies of Alzheimer's disease...
June 22, 2018: Biometrics
Ryan Smith, Anna Sanova, Anna Alkozei, Richard D Lane, William D S Killgore
Previous studies have suggested that trait differences in emotional awareness (tEA) are clinically relevant, and associated with differences in neural structure/function. While multiple leading theories suggest that conscious awareness requires widespread information integration across the brain, no study has yet tested the hypothesis that higher tEA corresponds to more efficient brain-wide information exchange. Twenty-six healthy volunteers (13 female) underwent a resting state functional magnetic resonance imaging scan, and completed the Levels of Emotional Awareness Scale (LEAS; a measure of tEA) and the Wechsler Abbreviated Scale of Intelligence (WASI-II; a measure of general intelligence [IQ])...
June 21, 2018: Social Cognitive and Affective Neuroscience
Jaume Coll-Font, Setareh Ariafar, Dana H Brooks
Respiratory motion is known to cause beat-to-beat variation of the ECG. This observation suggests that it may be possible to use this variation to track position and orientation of the heart. Electrocardiographic Imaging (ECGI) would benefit from such a reconstruction since one contribution to errors in its solutions is respiratory motion of the heart. ECGI solutions generally rely on prior computation of a "forward" model that relates cardiac electrical activity to ECGs. However, the ill-posed nature of the inverse solution leads to large errors in ECGI even for small amounts of error in the forward model...
September 2017: Computing in Cardiology
Altaib Al Yassin, Mohammad Salehi Sadaghiani, Suyash Mohan, R Nick Bryan, Ilya Nasrallah
RATIONALE AND OBJECTIVES: Efficiency is central to current radiology practice. Knowledge of report generation timing is essential for workload optimization and departmental staffing decisions. Yet little research evaluates the distribution of activities performed by neuroradiologists in daily work. MATERIALS AND METHODS: This observational study tracked radiologists interpreting 358 brain magnetic resonance imaging (MRI) in an academic practice over 9 months. We measured the total duration from study opening to report signing and times for five activities performed during this period: image viewing, report transcription, obtaining clinical data, education, and other...
June 18, 2018: Academic Radiology
Jian Zhang, Joseph R Lakowicz
Background: Near-field fluorescence (NFF) effects were employed to develop a novel near-infrared (NIR) luminescent nanoparticle (LNP) with superior brightness. The LNP is used as imaging contrast agent for cellular and small animal imaging and furthermore suggested to use for detecting voltage-sensitive calcium in living cells and animals with high sensitivity. Results: NIR Indocyanine green (ICG) dye was conjugated with human serum albumin (HSA) followed by covalently binding to gold nanorod (AuNR)...
2018: Cell & Bioscience
Raúl Caulier-Cisterna, Sergio Muñoz-Romero, Margarita Sanromán-Junquera, Arcadi García-Alberola, José Luis Rojo-Álvarez
BACKGROUND: The inverse problem in electrophysiology consists of the accurate estimation of the intracardiac electrical sources from a reduced set of electrodes at short distances and from outside the heart. This estimation can provide an image with relevant knowledge on arrhythmia mechanisms for the clinical practice. Methods based on truncated singular value decomposition (TSVD) and regularized least squares require a matrix inversion, which limits their resolution due to the unavoidable low-pass filter effect of the Tikhonov regularization techniques...
June 20, 2018: Biomedical Engineering Online
Agnieszka Szarkowska, Olivia Gerber-Morón
People watch subtitled audiovisual materials more than ever before. With the proliferation of subtitled content, we are also witnessing an increase in subtitle speeds. However, there is an ongoing controversy about what optimum subtitle speeds should be. This study looks into whether viewers can keep up with increasingly fast subtitles and whether the way people cope with subtitled content depends on their familiarity with subtitling and on their knowledge of the language of the film soundtrack. We tested 74 English, Polish and Spanish viewers watching films subtitled at different speeds (12, 16 and 20 characters per second)...
2018: PloS One
Deborah Queiroz Freitas, Rocharles Cavalcante Fontenele, Eduarda Helena Leandro Nascimento, Taruska Ventorini Vasconcelos, Marcel Noujeim
AIM: To evaluate the influence of kilovoltage (kVp) and metal artefact reduction tool (MAR) on the magnitude of cone beam computed tomography (CBCT) artifacts. METHODS: A titanium and zirconia implants were inserted alternately in a posterior region of a mandible. CBCT exams were acquired with ProMax 3D (Planmeca Oy, Helsinki, Finland) and Picasso Trio machines (Vatech, Hwaseong, South Korea) using 70 kVp, 80 kVp and 90 kVp with and without MAR activation. The other exposure factors remained fixed at 5mA, FOV 80 × 50 mm and voxel 0...
June 19, 2018: Dento Maxillo Facial Radiology
Hanlin Liu, Oscar M Curet
Undulatory fin propulsion exhibits high degree of maneuver control -- an ideal for underwater vessels exploring complex environments. In this work, we developed and tested a self-contained, free-swimming robot with a single undulating fin running along the length of the robot, which controls both forward motion and directional maneuvers. We successfully replicated several maneuvers including forward swimming, reversed motion, diving, station-keeping and vertical swimming. For each maneuver, a series of experiments were performed as a function of fin frequency, wavelength and traveling wave direction to measure swimming velocities, orientation angles and mean power consumption...
June 18, 2018: Bioinspiration & Biomimetics
Greg Ongie, Mathews Jacob
Fourier domain structured low-rank matrix priors are emerging as powerful alternatives to traditional image recovery methods such as total variation (TV) and wavelet regularization. These priors specify that a convolutional structured matrix, i.e., Toeplitz, Hankel, or their multi-level generalizations, built from Fourier data of the image should be low-rank. The main challenge in applying these schemes to large-scale problems is the computational complexity and memory demand resulting from a lifting the image data to a large scale matrix...
December 2017: IEEE Transactions on Computational Imaging
Tony Antony, Vivek Amin, Shourya Hegde, Shreya Hegde, Deepa Shetty, Mohammadi Begum Khan
Aims and Objectives: Managing mild-to-moderate Class II malocclusion is one of the common and major challenges to orthodontists. Class II discrepancies with mandibular deficiency during active growth are usually treated using myofunctional appliances. Fixed functional appliances evolved due to the noncompliance with conventional myofunctional appliances. One of the latest Class II correctors is the PowerScope appliance. The purpose of this study was to determine the amount, time, and rate of molar correction and efficacy of PowerScope...
May 2018: Journal of International Society of Preventive & Community Dentistry
Henrik Helin, Teemu Tolonen, Onni Ylinen, Petteri Tolonen, Juha Näpänkangas, Jorma Isola
Background: Whole slide images (WSIs, digitized histopathology glass slides) are large data files whose long-term storage remains a significant cost for pathology departments. Currently used WSI formats are based on lossy image compression alogrithms, either using JPEG or its more efficient successor JPEG 2000. While the advantages of the JPEG 2000 algorithm (JP2) are commonly recognized, its compression parameters have not been fully optimized for pathology WSIs. Methods: We defined an optimized parametrization for JPEG 2000 image compression, designated JP2-WSI, to be used specifically with histopathological WSIs...
2018: Journal of Pathology Informatics
Du-Juan Huang, Zhi-Mei Huang, Hu-Yan Xiao, Zhen-Kun Wu, Li-Juan Tang, Jian-Hui Jiang
Efficient intracellular delivery of nucleic acids to achieve sensitive detection and gene regulation is essential for chemistry and biology. Here we developed a novel protein scaffolded DNA tetrad, a four-arm DNA nanostructure constructed using streptavidin (SA) protein and four biotinylated hairpin DNA probes for efficient nucleic acid delivery and ultrasensitive miRNA imaging through crosslinking hybridization chain reaction (cHCR). DNA tetrads were easy to prepare and allowed precise control of the structure of the probes...
June 7, 2018: Chemical Science
Vojtěch Svatoš, Imrich Gablech, B Robert Ilic, Jan Pekárek, Pavel Neužil
Carbon nanotubes (CNTs) have near unity infrared (IR) absorption efficiency, making them extremely attractive in IR imaging devices. Since CNT growth occurs at elevated temperatures, integration of CNTs with IR imaging devices is challenging and has not yet been achieved. Here we show a strategy for implementing CNTs as IR absorbers using differential heating of thermally-isolated microbolometer membranes in a C2 H2 environment. During the process, CNTs were catalytically grown on the surface of a locally-heated membrane while the substrate was maintained at an ambient temperature...
March 2018: Journal of Applied Physics
David M Fisher, Spencer A Wood, Eric M White, Dale J Blahna, Sarah Lange, Alex Weinberg, Michael Tomco, Emilia Lia
Outdoor recreation is one of many important benefits provided by public lands. Data on recreational use are critical for informing management of recreation resources, however, managers often lack actionable information on visitor use for large protected areas that lack controlled access points. The purpose of this study is to explore the potential for social media data (e.g., geotagged images shared on Flickr and trip reports shared on a hiking forum) to provide land managers with useful measures of recreational use to dispersed areas, and to provide lessons learned from comparing several more traditional counting methods...
June 13, 2018: Journal of Environmental Management
Yu-Zi Lin, Kuang-Yuh Huang, Yuan Luo
Half-circle illumination-based differential phase contrast (DPC) microscopy has been utilized to recover phase images through a pair of images along multiple axes. Recently, the half-circle based DPC using 12-axis measurements significantly provides a circularly symmetric phase transfer function to improve accuracy for more stable phase recovery. Instead of using half-circle-based DPC, we propose a new scheme of DPC under radially asymmetric illumination to achieve circularly symmetric phase transfer function and enhance the accuracy of phase recovery in a more stable and efficient fashion...
June 15, 2018: Optics Letters
Bing Lei, Shugang Liu
We report a new quantitative measurement method of polarization direction based on the polarization axis finder (PAF) and digital image processing. The PAF acts as an azimuthal analyzer to determine the polarization direction of linearly polarized light and form an "hourglass" intensity pattern, and a digital camera is employed to record the pattern, and then the lightwave's polarization direction is obtained accurately by analyzing the pattern with a specially designed digital image processing algorithm...
June 15, 2018: Optics Letters
Tao Guo, Peng Gao, Li Fang, Li Guo, Yuchen Fan, Changgen Liu
The present prospective clinical observational study aimed to evaluate the efficacy of Toric intraocular lenses (IOL) to achieve rotational stability and astigmatism correction in eyes with high myopia. A total of 27 consecutive cataract patients (39 eyes) with pre-existing corneal astigmatism (1.5-3.5 D) were divided into two groups according to their refractive status: One group of 18 eyes with high myopia -(12.5-6.0 D) and another group consisting of 21 eyes with emmetropia or low myopia (-3.0-0.0 D). All eyes underwent cataract phacoemulsification surgeries by the same surgeon, with the implantation of an AcrySof® Toric IOL at the pre-designed degree...
June 2018: Experimental and Therapeutic Medicine
Jaeyub Hyun, Yong Tae Kim, Il Doh, Bongyoung Ahn, Kyungmin Baik, Se-Hwa Kim
In this study, we report the first experimental realization of an ultrathin (0.14λ, λ = 1.482 mm means wavelength at 1 MHz in the water medium) subwavelength focusing acoustic lens that can surpass the Rayleigh diffraction limit (0.61λ/NA, NA means numerical aperture). It is termed a Super-Oscillatory Acoustic Lens (SOAL), and it operates in the megasonic range. The SOAL represents an interesting feature allowing the achievement of subwavelength focusing without the need to operate in close proximity to the object to be imaged...
June 14, 2018: Scientific Reports
L Xi, P De Falco, E Barbieri, A Karunaratne, L Bentley, C T Esapa, N J Terrill, S D M Brown, R D Cox, G R Davis, N M Pugno, R V Thakker, H S Gupta
Glucocorticoid-induced osteoporosis (GIOP) is a major secondary form of osteoporosis, with the fracture risk significantly elevated - at similar levels of bone mineral density - in patients taking glucocorticoids compared with non-users. The adverse bone structural changes at multiple hierarchical levels in GIOP, and their mechanistic consequences leading to reduced load-bearing capacity, are not clearly understood. Here we combine experimental X-ray nanoscale mechanical imaging with analytical modelling of the bone matrix mechanics to determine mechanisms causing bone material quality deterioration during development of GIOP...
June 11, 2018: Acta Biomaterialia
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