scholarly journals 231: High-sensitivity, integrated near-infrared optical probe non-invasively measures human placental tissue oxygenation

2020 ◽  
Vol 222 (1) ◽  
pp. S161
Author(s):  
Nadav Schwartz ◽  
Lin Wang ◽  
Jeffrey Cochran ◽  
Tiffany Ko ◽  
Lian He ◽  
...  
Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 842
Author(s):  
Alejandro Vásquez ◽  
Francisco Pérez ◽  
Maximiliano Roa ◽  
Ignacio Sanhueza ◽  
Hugo Rojas ◽  
...  

In this paper, a novel optical technique for following the progress of the blister copper desulfurization process is presented. The technique is based on the changes observed in the continuous spectrum of the visible–near-infrared (VIS–NIR) radiation that the blister melt emits while the chemical reactions of the sulfur elimination process are taking place. Specifically, the proposed technique uses an optical probe composed of an optical fiber, a collimating lens, and a quartz tube, which is immersed in the melt. This optical probe provides a field of view of the blowing zone where the desulfurization reaction occurs. The experimental results show that the melt VIS–NIR total irradiance evolves inversely to the SO2 concentration reported by a gas analyzer based on differential optical absorption spectroscopy. Furthermore, the blister copper spectral emissivity as well as the total emissivity observed throughout the process show strong correlation with the sulfur content during desulfurization reaction.


2021 ◽  
Author(s):  
Yuyang Gu ◽  
Zhiyong Guo ◽  
Wei Yuan ◽  
Mengya Kong ◽  
Yulai Liu ◽  
...  

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He

An optical system for gaseous chloroform (CHCl3) detection based on wavelength modulation photoacoustic spectroscopy (WMPAS) is proposed for the first time by using a distributed feedback (DFB) laser with a center wavelength of 1683 nm where chloroform has strong and complex absorption peaks. The WMPAS sensor developed possesses the advantages of having a simple structure, high-sensitivity, and direct measurement. A resonant cavity made of stainless steel with a resonant frequency of 6390 Hz was utilized, and eight microphones were located at the middle of the resonator at uniform intervals to collect the sound signal. All of the devices were integrated into an instrument box for practical applications. The performance of the WMPAS sensor was experimentally demonstrated with the measurement of different concentrations of chloroform from 63 to 625 ppm. A linear coefficient R2 of 0.999 and a detection sensitivity of 0.28 ppm with a time period of 20 s were achieved at room temperature (around 20 °C) and atmosphere pressure. Long-time continuous monitoring for a fixed concentration of chloroform gas was carried out to demonstrate the excellent stability of the system. The performance of the system shows great practical value for the detection of chloroform gas in industrial applications.


2019 ◽  
Vol 16 (11) ◽  
pp. 115602
Author(s):  
D M Kustov ◽  
A S Sharova ◽  
V I Makarov ◽  
A V Borodkin ◽  
T A Saveleva ◽  
...  

2013 ◽  
Vol 17 (01n02) ◽  
pp. 99-103 ◽  
Author(s):  
Hui He ◽  
Jian-Yong Liu ◽  
Dennis K.P. Ng

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.


2016 ◽  
Vol 4 (48) ◽  
pp. 7845-7851 ◽  
Author(s):  
Junpeng Shi ◽  
Meng Sun ◽  
Xia Sun ◽  
Hongwu Zhang

Near-infrared persistent luminescence hollow mesoporous nanospheres have been synthesized via a template method. These nanospheres can be used as large capacity drug carriers and realize super long-term and high sensitivity tracking of drug delivery in deep tissue.


2016 ◽  
Vol 22 (2) ◽  
pp. 71-82 ◽  
Author(s):  
Marco Roverso ◽  
Maura Brioschi ◽  
Cristina Banfi ◽  
Silvia Visentin ◽  
Silvia Burlina ◽  
...  

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