Near-Infrared-Emitting Probes for Detection of Nanomolar Hydrazine in a Complete Aqueous Medium with Real-Time Application in Bioimaging and Vapor-Phase Hydrazine Detection

2020 ◽  
Vol 8 (11) ◽  
pp. 4457-4463 ◽  
Author(s):  
Natarajan Vijay ◽  
Sivan Velmathi
Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5209 ◽  
Author(s):  
Andrea Gonzalez-Rodriguez ◽  
Jose L. Ramon ◽  
Vicente Morell ◽  
Gabriel J. Garcia ◽  
Jorge Pomares ◽  
...  

The main goal of this study is to evaluate how to optimally select the best vibrotactile pattern to be used in a closed loop control of upper limb myoelectric prostheses as a feedback of the exerted force. To that end, we assessed both the selection of actuation patterns and the effects of the selection of frequency and amplitude parameters to discriminate between different feedback levels. A single vibrotactile actuator has been used to deliver the vibrations to subjects participating in the experiments. The results show no difference between pattern shapes in terms of feedback perception. Similarly, changes in amplitude level do not reflect significant improvement compared to changes in frequency. However, decreasing the number of feedback levels increases the accuracy of feedback perception and subject-specific variations are high for particular participants, showing that a fine-tuning of the parameters is necessary in a real-time application to upper limb prosthetics. In future works, the effects of training, location, and number of actuators will be assessed. This optimized selection will be tested in a real-time proportional myocontrol of a prosthetic hand.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.


2021 ◽  
Vol 714 (4) ◽  
pp. 042046
Author(s):  
Jiangping Nan ◽  
Yajuan Jia ◽  
Xuezhen Dai ◽  
Yinglu Liu ◽  
Xiaowen Ren ◽  
...  

2021 ◽  
Author(s):  
Shilpi Jaiswal ◽  
Subhankar Kundu ◽  
Sujoy Bandyopadhyay ◽  
Abhijit Patra

An organic–inorganic hybrid upconversion nanoprobe was developed for the real-time detection of aliphatic biogenic amines in an aqueous medium, adulterated milk, and rotten fish.


Talanta ◽  
2021 ◽  
Vol 228 ◽  
pp. 122184
Author(s):  
Qingfeng Xia ◽  
Shumin Feng ◽  
Jiaxin Hong ◽  
Guoqiang Feng

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