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optic flow

Eleonora Corbelli, Riccardo Sacconi, Alessandro Rabiolo, Stefano Mercuri, Adriano Carnevali, Lea Querques, Francesco Bandello, Giuseppe Querques
Purpose: To investigate the application of optical coherence tomography angiography (OCT-A) in evaluation of geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Methods: Patients with GA were prospectively enrolled and studied with blue fundus autofluorescence (FAF), en face structural OCT, and OCT-A. OCT-A images were acquired using a slab of whole choroid, whereas en face structural OCT images were obtained at the ellipsoid zone (EZ), at the choroidal (CH) level, and at the scleral (SC) level...
October 1, 2017: Investigative Ophthalmology & Visual Science
Sergio Caballero, David L Kent, Nilanjana Sengupta, Sergio Li Calzi, Lynn Shaw, Eleni Beli, Leni Moldovan, James M Dominguez, Ramana S Moorthy, Maria B Grant
Purpose: We investigated whether subthreshold retinal phototherapy (SRPT) was associated with recruitment of bone marrow (BM)-derived cells to the neurosensory retina (NSR) and RPE layer. Methods: GFP chimeric mice and wild-type (WT) mice were subjected to SRPT using a slit-lamp infrared laser. Duty cycles of 5%, 10%, 15%, and 20% (0.1 seconds, 250 mW, spot size 50 μm) with 30 applications were placed 50 to 100 μm from the optic disc. In adoptive transfer studies, GFP+ cells were given intravenously immediately after WT mice received SRPT...
October 1, 2017: Investigative Ophthalmology & Visual Science
Yoshihiro Imai, Takehiro Yamashita, On Topaz
RATIONALE: Thin-cap fibroatheroma (TCFA) and red thrombus are suggested as a high-risk of embolic complications during percutaneous coronary intervention (PCI). Intracoronary aspiration procedures occasionally result in either an insufficient thrombus removal or provide no significant effects on TCFA. PATIENT CONCERNS: A 76-year-old male underwent coronary angiography for chest pain. DIAGNOSES: Coronary angiography revealed a tight stenosis at the right coronary artery which resulted in treatment by PCI...
October 2017: Medicine (Baltimore)
Dermot J Kelly, Sinéad M Farrell
More than 26 million Americans suffer with cataracts, and with 3.6 million cataract extractions performed annually in the United States, it is the most common surgical procedure. The integrity of the delicate structures of the eye that mediate vision is dependent on the intraocular pressure (IOP). Yet, IOP acts to compress the vessels within the globe-akin to a Starling resistor-and is a key component that determines the ocular perfusion pressure, defined as the difference between arterial pressure and IOP...
October 17, 2017: Anesthesia and Analgesia
Judit Barroso, John McCallum, Dan Long
Kochia (Kochia scoparia L.), Russian thistle (Salsolatragus L.), and prickly lettuce (Lactuca serriola L.) are economically important weeds infesting dryland wheat (Triticum aestivum L.) production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest...
October 19, 2017: Sensors
Kamal G Shah, Paul Yager
Porous media made of nitrocellulose and glass fiber are common "paper" substrates for lateral flow assays, microfluidic paper analytical devices, and other point-of-care diagnostic assays. Such assays commonly use optical labels such as gold nanoparticles, latex beads, or fluorescent nanoparticles to visualize the presence of analytes. Fluorescent labels are commonly used in bioassays to enhance sensitivity, but autoluminescence of the paper substrate worsens signal-to-noise ratios of fluorescence-based assays...
October 19, 2017: Analytical Chemistry
Jing Samantha Pan, Ned Bingham, Chang Chen, Geoffrey P Bingham
Use of motion to break camouflage extends back to the Cambrian [In the Blink of an Eye: How Vision Sparked the Big Bang of Evolution (New York Basic Books, 2003)]. We investigated the ability to break camouflage and continue to see camouflaged targets after motion stops. This is crucial for the survival of hunting predators. With camouflage, visual targets and distracters cannot be distinguished using only static image structure (i.e., appearance). Motion generates another source of optical information, optic flow, which breaks camouflage and specifies target locations...
August 1, 2017: Applied Optics
S Maidul Haque, Rajnarayan De, S Tripathi, C Mukherjee, A K Yadav, Dibyendu Bhattacharyya, S N Jha, N K Sahoo
Gadolinium oxide is an excellent optical material that offers high transmission in a wide wavelength range of 200-1600 nm and exhibits a high bulk refractive index of ∼1.80 at 550 nm. In the present study, a set of Gd2O3 thin films has been deposited on fused silica substrates by RF sputtering of a Gd2O3 target under various O2 to Ar flow ratios. The samples have been characterized by grazing incidence x-ray diffraction (GIXRD) to study the long range structural behavior, by GIXR to study density and surface roughness of the films, by atomic force microscopy measurements to study morphological properties, by Rutherford backscattering measurements for compositional studies, and by transmission spectrophotometry and spectroscopic ellipsometry techniques to study their optical properties...
August 1, 2017: Applied Optics
Haolin Ding, Shihe Yi, Yangzhu Zhu, Lin He
Nanoparticle-based planar laser scattering was used to measure the density distribution of the supersonic (Ma=3.0) turbulent boundary layer and the optical path difference (OPD), which is quite crucial for aero-optics study. Results were obtained using ray tracing. The influences of different layers in the boundary layer, turbulence scales, and light incident angle on aero-optics were examined, and the underlying flow physics were analyzed. The inner layer plays a dominant role, followed by the outer layer...
September 20, 2017: Applied Optics
Guangming Guo, Hong Liu
A correction strategy for correcting the aero-optical wavefront aberration of the supersonic mixing layer is presented based on flow control that is implemented by periodic pulse forcing. The flow field of the controlled supersonic mixing layer is simulated by large eddy simulation, and the optical transmission trajectory of the incident beam is computed by the ray-tracing method. The key component of the correction strategy is a compensation signal employed to correct the aberrated wavefront, which is produced according to flow and control parameters...
June 1, 2017: Applied Optics
Rüdiger Beermann, Lorenz Quentin, Andreas Pösch, Eduard Reithmeier, Markus Kästner
To optically capture the topography of a hot measurement object with high precision, the light deflection by the inhomogeneous refractive index field-induced by the heat transfer from the measurement object to the ambient medium-has to be considered. We used the 2D background oriented schlieren method with illuminated wavelet background, an optical flow algorithm, and Ciddor's equation to quantify the refractive index field located directly above a red-glowing, hot measurement object. A heat transfer simulation has been implemented to verify the magnitude and the shape of the measured refractive index field...
May 10, 2017: Applied Optics
Jianhui Zhuang, Yang Han, Dachun Xu, Guofu Zhu, Shekhar Singh, Luoman Chen, Mengyun Zhu, Wei Chen, Yawei Xu, Xiankai Li
BACKGROUND: While specific patterns of circulating dendritic cells (DCs) and monocytes are associated with the incidence of coronary artery disease, the characterization of circulating DC and monocyte subsets in patients with different stages of atherosclerosis remains unclear. METHODS: Forty-eight patients with unstable angina pectoris (UAP) diagnosed by angiography were enrolled. Likewise, 31 patients with ST-segment elevation myocardial infarction (STEMI) were enrolled and confirmed with the presence of thrombosis by angiography...
October 18, 2017: BMC Cardiovascular Disorders
William K Page, Charles J Duffy
We presented optic flow and real movement heading stimuli while recording MSTd neuronal activity. Monkeys were alternately engaged in three tasks: visual detection of optic flow heading perturbations, vestibular detection of real movement heading perturbations, and auditory detection of brief tones. Push-button RTs were fastest for tones, and slower for visual and vestibular heading perturbations, suggesting that the tone detection task was easier. Neuronal heading selectivity was strongest during the tone detection task, and weaker during the visual and vestibular heading perturbation detection tasks...
October 18, 2017: Journal of Neurophysiology
Eric K W Poon, Vikas Thondapu, Eve Revalor, Andrew Ooi, Peter Barlis
No abstract text is available yet for this article.
October 17, 2017: European Heart Journal
Leila Gharibshahi, Elias Saion, Elham Gharibshahi, Abdul Halim Shaari, Khamirul Amin Matori
Very narrow and pure silver nanoparticles were synthesized by modified thermal treatment method via oxygen and nitrogen flow in succession. The structural and optical properties of the calcined silver nanoparticles at 600°C with diverse Poly(vinylpyrrolidone) concentrations varied from 2% to 4% were studied by means of different techniques. Fourier transform infrared spectroscopy was used to monitor the production of pure Ag nanoparticles at a given Poly(vinylpyrrolidone) concentration. The X-ray powder diffraction spectra are evidence for the transformation of the amorphous sample at 30°C to the cubic crystalline nanostructures at the calcination temperatures for all Poly(vinylpyrrolidone) concentrations...
2017: PloS One
Monica Allen, Oles Shtanko, Ion Cosma Fulga, Joel I-Jan Wang, Daniyar Nurgaliev, Kenji Watanabe, Takashi Taniguchi, Anton Akhmerov, Pablo Jarillo-Herrero, Leonid Levitov, Amir Yacoby
Electron surface states in solids are typically confined to the outermost atomic layers and, due to surface disorder, have negligible impact on electronic transport. Here we demonstrate a very different behavior for surface states in graphene. We probe the wavelike character of these states by Fabry-Perot (FP) interferometry and find that, in contrast to theoretical predictions, these states can propagate ballistically over micron-scale distances. This is achieved by embedding a graphene resonantor formed by gate-defined p-n junctions within a graphene SNS structure...
October 18, 2017: Nano Letters
Keisuke Hibino, Masatomo Yashima, Takayoshi Oshima, Kotaro Fujii, Kazuhiko Maeda
Tungsten-modified barium tantalum oxynitride is a new visible-light photocatalyst for water oxidation. In the present work, novel barium tantalum strontium tungsten oxynitride solid solutions, (BaTaO2N)1-x(SrWO2N)x, with a cubic Pm3[combining macron]m perovskite-type structure (x = 0.01 and 0.02) have been prepared by heating oxide precursors under an ammonia flow. These (BaTaO2N)1-x(SrWO2N)x catalysts exhibited photocatalytic water oxidation activity under visible light irradiation. The crystal structure, electron-density distribution, and optical properties of (BaTaO2N)1-x(SrWO2N)x (x = 0, 0...
October 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Giuseppe Lo Giudice, Alessandro Galan
We describe features of a circumscribed choroidal hemangioma (CCH) treated with photodynamic therapy (PDT) by means of optical coherence tomography angiography (OCT-A). A 40-year-old man had a complaint of decreasing visual acuity in his left eye for 10 days. A diagnosis of CCH was confirmed by fundus examination, fluorescein angiography, and indocyanine green angiography. An OCT-A study of choroidal lesion before and after PDT was carried out. Segmented en face OCT-A of CCH showed multiple irregular connected vascular channels with hyperflow and a capillary-like lesion...
October 2017: Indian Journal of Ophthalmology
Xiao Shu, Wenzhong Liu, Lian Duan, Hao F Zhang
Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping...
October 2017: Journal of Biomedical Optics
Lawrence R Griffing
In this chapter, approaches to the image analysis of the choreography of the plant endoplasmic reticulum (ER) labeled with fluorescent fusion proteins ("stars," if you wish) are presented. The approaches include the analyses of those parts of the ER that are attached through membrane contact sites to moving or nonmoving partners (other "stars"). Image analysis is also used to understand the nature of the tubular polygonal network, the hallmark of this organelle, and how the polygons change over time due to tubule sliding or motion...
2018: Methods in Molecular Biology
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