Contrast-enhanced wide-angle high-speed polarization modulator for active-retarder 3-D displays

2012 ◽  
Vol 20 (3) ◽  
pp. 169
Author(s):  
Jesper Osterman ◽  
Terry Scheffer
Keyword(s):  
High Speed ◽  
Wide Angle ◽  
Polarization Modulator ◽  
Contrast Enhanced

Abstract 5763: Dynamic Contrast-Enhanced MRI Detects Early Plaque Progression in a Rabbit Model of Atherosclerosis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
William S Kerwin ◽  
Jerry Ricks ◽  
Michael Rosenfeld
Keyword(s):  
Vessel Wall ◽  
High Speed ◽  
Rabbit Model ◽  
Atherosclerotic Lesion ◽  
Intraplaque Hemorrhage ◽  
Slice Thickness ◽  
Dce Mri ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Plaque Inflammation

Recent studies have used dynamic contrast-enhanced (DCE) MRI to quantify the rate of uptake of gadolinium contrast agents in atherosclerotic plaque. The transfer constant K trans , that quantifies the blood supply and permeability of the plaque, shows strong association with plaque inflammation. The purpose of this study was to explore the link between K trans and plaque inflammation in a model of early atherosclerotic lesion development. Twelve NZW rabbits were placed on a 0.2% cholesterol diet and underwent balloon injury of the descending aorta. After 12 weeks, all rabbits underwent a DCE-MRI exam, after which 6 were euthanized and perfusion fixed to harvest the atherosclerotic aortas. The remaining 6 were imaged again at 24 weeks and their aortas were harvested. The DCE-MRI procedure utilized a unique, high-speed, small field-of-view imaging technique with quadruple inversion recovery blood suppression (turbo spin echo, TR=800 ms, TE=9ms, 3mm slice thickness, 0.5mm in-plane resolution). This allowed us to observe enhancement of the vessel wall without contamination from enhancement of the adjacent lumen. The DCE-MRI results were analyzed to determine the average, relative K trans in the vessel wall and compared to histological assessments of the aortas. K trans was significantly higher at 6 months compared to 3 months within the same animals (p<0.005) and compared to those euthanized at 3 months (p<0.001). No difference was observed between the two groups at 3 months (p=0.4). Histologically, aorta cross sections at 6 months had lesions that were no thicker than those at 3 months (0.49 vs. 0.45mm, p=0.6), but complex lesion features including necrotic cores, intraplaque hemorrhage, neovessels, and deep clusters of macrophages were significantly more common at 6 months (82% vs. 18%, p<0.001). The transformation of the lesions from simple to complex morphologies from 12 weeks to 24 coincided with a significant rise in K trans . We attribute this rise to the development of neovessels in response to pro-inflammatory stimuli. We conclude that K trans can be used to probe lesion characteristics and complexity in early atherosclerosis, with applications in early diagnosis and treatment monitoring. This research has received full or partial funding support from the American Heart Association, AHA Pacific/Mountain Affiliate (Alaska, Arizona, Colorado, Hawaii, Idaho, Montana, Oregon, Washington & Wyoming).

scholarly journals Design of Wide Angle and Large Aperture Optical System with Inner Focus for Compact System Camera Applications

2019 ◽  
Vol 10 (1) ◽  
pp. 179 ◽  
Author(s):  
Hojong Choi ◽  
Jaemyung Ryu
Keyword(s):  
Optical System ◽  
High Speed ◽  
Resolving Power ◽  
Wide Angle ◽  
Phase Detection ◽  
Half Angle ◽  
Stepper Motors ◽  
Angle Of View ◽  
Floating Type ◽  
Focusing Lens

Conventionally, a bright, very wide-angle optical system is designed as a floating type optical system that moves two or more lens groups composed of multiple lens in order to focus accurately. These have been widely used as phase detection auto focus (AF) methods within conventional digital single-lens reflex (DSLR) cameras. However, a phase detection AF optical system cannot be used when recording motion pictures. In contrast, a compact system camera (CSC) performs AF by the contrast method, where a stepper motor is used as the driving source for moving the optical lens. Nonetheless, to ensure that the focusing lens is lighter, these stepper motors should not have high torque and AF must be possible by moving only one lens. Yet, when focusing is performed with only one lens, aberration change due to focusing lens movement is magnified. Therefore, a very wide-angle optical system comprised of a half-angle of view more than 40 degrees and F of 1/4 has not been developed. Here, a very wide-angle optical system was designed with high resolving power that enables high speed AF, even in contrast mode, by moving only one lens while minimizing aberration change.

Development of high-speed and wide-angle visible observation diagnostics on Experimental Advanced Superconducting Tokamak using catadioptric optics

2013 ◽  
Vol 84 (8) ◽  
pp. 085102 ◽  
Author(s):  
J. H. Yang ◽  
X. F. Yang ◽  
L. Q. Hu ◽  
Q. Zang ◽  
X. F. Han ◽  
...  
Keyword(s):  
High Speed ◽  
Wide Angle ◽  
Superconducting Tokamak

High-speed waveguide electro-optic polarization modulator

1982 ◽  
Vol 7 (10) ◽  
pp. 500 ◽  
Author(s):  
R. C. Alferness ◽  
L. L. Buhl
Keyword(s):  
High Speed ◽  
Polarization Modulator ◽  
Electro Optic

Mt. Dushak-Erekdag Observatory: A Chance to Close the Asian Gaps in WET Coverage

2003 ◽  
Vol 12 (2) ◽  
Author(s):  
T. N. Dorokhova ◽  
N. I. Dorokhov
Keyword(s):  
Soviet Union ◽  
Central Asia ◽  
Former Soviet Union ◽  
High Speed ◽  
Astronomical Observatory ◽  
Light Pollution ◽  
Wide Angle ◽  
International Programs ◽  
Low Light ◽  
Stable Economy

AbstractThe Mt. Dushak-Erekdag Observatory (Central Asia, Turkmenistan, 58° E longitude) is located just in the longitudes gap of asteroseismological networks. It is the southernmost observatory of the former Soviet Union, its latitude is +38°. The sky seeing at the site is one of the best in Central Asia: a low light pollution, high and stable sky transparency, over 200 usable nights per year. The altitude is above 2000 m.Odessa Astronomical Observatory has its 0.8 m telescope with a two-star high-speed photometer there, which frequently participates in international programs and multi-site campaigns. An accuracy of the photometry amounts to 1 mmag. Besides, a 1 m wide-angle telescope and a dual-tube telescope with 0.5m mirrors are installed at the observatory.The developed infrastructure at the site and the stable economy in Turkmenistan make the Mt. Dushak-Erekdag Observatory very interesting for the WET observations.

Filament identification in wide-angle high speed imaging of the mega amp spherical tokamak

2019 ◽  
Vol 90 (9) ◽  
pp. 093502
Author(s):  
T. Farley ◽  
N. R. Walkden ◽  
F. Militello ◽  
M. Sanna ◽  
J. Young ◽  
...  
Keyword(s):  
High Speed ◽  
Spherical Tokamak ◽  
Wide Angle ◽  
High Speed Imaging

High-speed imaging and tracking of very small single nanoparticles by contrast enhanced microscopy

Nanoscale ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 568-577 ◽  
Author(s):  
Ching-Ya Cheng ◽  
Yi-Hung Liao ◽  
Chia-Lung Hsieh
Keyword(s):  
High Speed ◽  
Direct Visualization ◽  
High Speed Imaging ◽  
Contrast Enhanced

Direct visualization of single 10 nm nanoparticles at 1000 frames per second is achieved by using coherent brightfield (COBRI) microscopy.

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