scholarly journals Self-Calibration Phenomenon for Near-Infrared Clinical Measurements: Theory, Simulation, and Experiments

ACS Omega ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 2837-2844 ◽  
Author(s):  
Idit Feder ◽  
Hamootal Duadi ◽  
Ruchira Chakraborty ◽  
Dror Fixler
Keyword(s):  
Near Infrared ◽  
Self Calibration ◽  
Clinical Measurements

scholarly journals 3D Calibration Test-Field for Digital Cameras Mounted on Unmanned Aerial Systems (UAS)

2018 ◽  
Vol 10 (12) ◽  
pp. 2017 ◽  
Author(s):  
Valeria-Ersilia Oniga ◽  
Norbert Pfeifer ◽  
Ana-Maria Loghin
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Digital Camera ◽  
Field Measurements ◽  
Unmanned Aerial Systems ◽  
Test Field ◽  
Digital Cameras ◽  
Self Calibration ◽  
Technological Developments ◽  
Aerial Systems

Due to the large number of technological developments in recent years, UAS systems are now used for monitoring purposes and in projects with high precision demand, such as 3D model-based creation of dams, reservoirs, historical monuments etc. These unmanned systems are usually equipped with an automatic pilot device and a digital camera (photo/video, multispectral, Near Infrared etc.), of which the lens has distortions; but this can be determined in a calibration process. Currently, a method of “self-calibration” is used for the calibration of the digital cameras mounted on UASs, but, by using the method of calibration based on a 3D calibration object, the accuracy is improved in comparison with other methods. Thus, this paper has the objective of establishing a 3D calibration field for the digital cameras mounted on UASs in terms of accuracy and robustness, being the largest reported publication to date. In order to test the proposed calibration field, a digital camera mounted on a low-cost UAS was calibrated at three different heights: 23 m, 28 m, and 35 m, using two configurations for image acquisition. Then, a comparison was made between the residuals obtained for a number of 100 Check Points (CPs) using self-calibration and test-field calibration, while the number of Ground Control Points (GCPs) variedand the heights were interchanged. Additionally, the parameters where tested on an oblique flight done 2 years before calibration, in manual mode at a medium altitude of 28 m height. For all tests done in the case of the double grid nadiral flight, the parameters calculated with the proposed 3D field improved the results by more than 50% when using the optimum and a large number of GCPs, and in all analyzed cases with 75% to 95% when using a minimum of 3 GCP. In this context, it is necessary to conduct accurate calibration in order to increase the accuracy of the UAS projects, and also to reduce field measurements.

Construction of a near-infrared responsive upconversion nanoplatform against hypoxic tumors via NO-enhanced photodynamic therapy

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7875-7887 ◽  
Author(s):  
Ying Lan ◽  
Xiaohui Zhu ◽  
Ming Tang ◽  
Yihan Wu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Near Infrared ◽  
Upconversion Nanoparticles

A near-infrared (NIR) activated theranostic nanoplatform based on upconversion nanoparticles (UCNPs) is developed in order to overcome the hypoxia-associated resistance in photodynamic therapy by photo-release of NO upon NIR illumination.

A nitroreductase-activatable near-infrared theranostic photosensitizer for photodynamic therapy under mild hypoxia

2020 ◽  
Vol 56 (43) ◽  
pp. 5819-5822
Author(s):  
Jing Zheng ◽  
Yongzhuo Liu ◽  
Fengling Song ◽  
Long Jiao ◽  
Yingnan Wu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Triplet State ◽  
Near Infrared ◽  
Mild Hypoxia

In this study, a near-infrared (NIR) theranostic photosensitizer was developed based on a heptamethine aminocyanine dye with a long-lived triplet state.

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

443: Can Self-Calibration Prevent Urethral Stricture Recurrence Following Direct Visual Internal Urethrotomy?

2005 ◽  
Vol 173 (4S) ◽  
pp. 121-121
Author(s):  
Hari Siva Gurunadha Rao Tunuguntla ◽  
P.V.L.N. Murthy ◽  
K. Sasidharan
Keyword(s):  
Urethral Stricture ◽  
Internal Urethrotomy ◽  
Self Calibration ◽  
Stricture Recurrence
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