scholarly journals Residue-resolved monitoring of protein hyperpolarization at sub-second time resolution

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mattia Negroni ◽  
Dennis Kurzbach
Keyword(s):  
Real Time ◽  
Nuclear Polarization ◽  
Sampling Rate ◽  
Spin States ◽  
Nuclear Spins ◽  
Protein Residues ◽  
Physiological Conditions ◽  
Strong Signal ◽  
Far From Equilibrium ◽  
Nmr Signals

AbstractSignal-enhancement techniques for NMR spectroscopy are important to amplify the weak resonances provided by nuclear spins. Recently, ‘hyperpolarization’ techniques have been intensively investigated. These provide nuclear spin states far from equilibrium yielding strong signal boosts up to four orders of magnitude. Here we propose a method for real-time NMR of ‘hyperpolarized’ proteins at residue resolution. The approach is based on dissolution dynamic nuclear polarization (d-DNP), which enables the use of hyperpolarized buffers that selectively boost NMR signals of solvent-exposed protein residues. The resulting spectral sparseness and signal enhancements enable recording of residue-resolved spectra at a 2 Hz sampling rate. Thus, we monitor the hyperpolarization level of different protein residues simultaneously under near-physiological conditions. We aim to address two points: 1) NMR experiments are often performed under conditions that increase sensitivity but are physiologically irrelevant; 2) long signal accumulation impedes fast real-time monitoring. Both limitations are of fundamental relevance to ascertain pharmacological relevance and study protein kinetics.

scholarly journals Residue-resolved monitoring of protein hyperpolarization at sub-second time resolution

2021 ◽  
Author(s):  
Mattia Negroni ◽  
Dennis Kurzbach
Keyword(s):  
Real Time ◽  
Nuclear Polarization ◽  
Sampling Rate ◽  
Signal Averaging ◽  
Protein Residues ◽  
Physiological Conditions ◽  
Interaction Kinetics ◽  
Conventional Solution ◽  
Nmr Signals

Abstract We propose a method for real-time nuclear magnetic resonance (NMR) spectroscopy of hyperpolarized proteins at residue resolution. The approach is based on dissolution dynamic nuclear polarization (d-DNP), which enables the use of hyperpolarized buffers that selectively boost NMR signals of backbone amides that incur magnetization fast from their surroundings. Capitalizing on the resulting spectral sparseness and simultaneous signal enhancement, we obtained residue-resolved NMR spectra at a sampling rate of 2 Hz. We could thus track the evolution of hyperpolarization at different protein residues simultaneously with time. This was achieved under near-physiological conditions, i.e., in aqueous solution at physiological salt concentration and at 37° C. With this development, two often encountered limitations of conventional solution-state NMR can be addressed: 1) NMR experiments are typically performed under conditions that increase sensitivity but are physiologically not relevant (low pH, low temperature) and; 2) signal accumulation over long periods impedes the determination of fast (on the order of seconds) real-time monitoring. Both limitations are of equal fundamental relevance: interaction studies under non-native conditions are of limited pharmacological relevance, and the key to the function of proteins often resides in their interaction kinetics. The proposed technique possibly opens new routes towards residue and temporally resolved spectroscopy at the atomistic level by overcoming the need for signal averaging in residue-resolved protein biomolecular NMR.

scholarly journals An Improved Multipath Mitigation Method and Its Application in Real-Time Bridge Deformation Monitoring

2021 ◽  
Vol 13 (12) ◽  
pp. 2259
Author(s):  
Ruicheng Zhang ◽  
Chengfa Gao ◽  
Qing Zhao ◽  
Zihan Peng ◽  
Rui Shang
Keyword(s):  
Real Time ◽  
Sampling Rate ◽  
Threshold Value ◽  
Deformation Monitoring ◽  
Success Rates ◽  
Multipath Mitigation ◽  
Mode Decomposition ◽  
Observation Noise ◽  
Original Observation ◽  
Better Than

A multipath is a major error source in bridge deformation monitoring and the key to achieving millimeter-level monitoring. Although the traditional MHM (multipath hemispherical map) algorithm can be applied to multipath mitigation in real-time scenarios, accuracy needs to be further improved due to the influence of observation noise and the multipath differences between different satellites. Aiming at the insufficiency of MHM in dealing with the adverse impact of observation noise, we proposed the MHM_V model, based on Variational Mode Decomposition (VMD) and the MHM algorithm. Utilizing the VMD algorithm to extract the multipath from single-difference (SD) residuals, and according to the principle of the closest elevation and azimuth, the original observation of carrier phase in the few days following the implementation are corrected to mitigate the influence of the multipath. The MHM_V model proposed in this paper is verified and compared with the traditional MHM algorithm by using the observed data of the Forth Road Bridge with a seven day and 10 s sampling rate. The results show that the correlation coefficient of the multipath on two adjacent days was increased by about 10% after residual denoising with the VMD algorithm; the standard deviations of residual error in the L1/L2 frequencies were improved by 37.8% and 40.7%, respectively, which were better than the scores of 26.1% and 31.0% for the MHM algorithm. Taking a ratio equal to three as the threshold value, the fixed success rates of ambiguity were 88.0% without multipath mitigation and 99.4% after mitigating the multipath with MHM_V. The MHM_V algorithm can effectively improve the success rate, reliability, and convergence rate of ambiguity resolution in a bridge multipath environment and perform better than the MHM algorithm.

scholarly journals RTLIO: Real-Time LiDAR-Inertial Odometry and Mapping for UAVs

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3955
Author(s):  
Jung-Cheng Yang ◽  
Chun-Jung Lin ◽  
Bing-Yuan You ◽  
Yin-Long Yan ◽  
Teng-Hu Cheng
Keyword(s):  
Feedback Control ◽  
Real Time ◽  
High Frequency ◽  
Indoor Environment ◽  
Indoor Localization ◽  
Sampling Rate ◽  
Outdoor Environment ◽  
Position Accuracy ◽  
Graph Optimization ◽  
Pose Graph Optimization

Most UAVs rely on GPS for localization in an outdoor environment. However, in GPS-denied environment, other sources of localization are required for UAVs to conduct feedback control and navigation. LiDAR has been used for indoor localization, but the sampling rate is usually too low for feedback control of UAVs. To compensate this drawback, IMU sensors are usually fused to generate high-frequency odometry, with only few extra computation resources. To achieve this goal, a real-time LiDAR inertial odometer system (RTLIO) is developed in this work to generate high-precision and high-frequency odometry for the feedback control of UAVs in an indoor environment, and this is achieved by solving cost functions that consist of the LiDAR and IMU residuals. Compared to the traditional LIO approach, the initialization process of the developed RTLIO can be achieved, even when the device is stationary. To further reduce the accumulated pose errors, loop closure and pose-graph optimization are also developed in RTLIO. To demonstrate the efficacy of the developed RTLIO, experiments with long-range trajectory are conducted, and the results indicate that the RTLIO can outperform LIO with a smaller drift. Experiments with odometry benchmark dataset (i.e., KITTI) are also conducted to compare the performance with other methods, and the results show that the RTLIO can outperform ALOAM and LOAM in terms of exhibiting a smaller time delay and greater position accuracy.

scholarly journals Systematic Review on Human Skin-Compatible Wearable Photoplethysmography Sensors

2021 ◽  
Vol 11 (5) ◽  
pp. 2313
Author(s):  
Inho Lee ◽  
Nakkyun Park ◽  
Hanbee Lee ◽  
Chuljin Hwang ◽  
Joo Hee Kim ◽  
...  
Keyword(s):  
Systematic Review ◽  
Health Care ◽  
Real Time ◽  
Human Skin ◽  
State Of The Art ◽  
Electronic Devices ◽  
Semiconducting Materials ◽  
Physiological Conditions ◽  
Technological Developments ◽  
Monitoring Technologies

The rapid advances in human-friendly and wearable photoplethysmography (PPG) sensors have facilitated the continuous and real-time monitoring of physiological conditions, enabling self-health care without being restricted by location. In this paper, we focus on state-of-the-art skin-compatible PPG sensors and strategies to obtain accurate and stable sensing of biological signals adhered to human skin along with light-absorbing semiconducting materials that are classified as silicone, inorganic, and organic absorbers. The challenges of skin-compatible PPG-based monitoring technologies and their further improvements are also discussed. We expect that such technological developments will accelerate accurate diagnostic evaluation with the aid of the biomedical electronic devices.

Intelligent Displacement Measuring System for Rock Stratum

2011 ◽  
Vol 103 ◽  
pp. 583-586
Author(s):  
Feng Ling Li ◽  
Jian Hua Rong ◽  
Yu Ping Zhang
Keyword(s):  
Civil Engineer ◽  
Real Time ◽  
Sampling Rate ◽  
Measuring System ◽  
Displacement Sensor ◽  
Rock Stratum ◽  
Baud Rate ◽  
Real Time Clock ◽  
High Sampling Rate ◽  
Displacement System

Measuring rock stratum displacement in dam grouting process is very important. A new displacement system is designed, comprising a programmable microcontroller Atmega16, a new grating capacitive displacement sensor(GCDS), DS1302 real time clock chip and announciator etc. The system has high sampling rate of 9600 baud rate and can trap the displacement equal to 0.001 millimeter in one second. Equipped with mechanical conveyance system, the system can be applied to the civil engineer. The experiment results show the instrument can measure accurately the displacement value and alarm geologic disaster in time, which can conduct continuous and accurate monitoring and provide operation decisions for dam engineers.

scholarly journals A method for identifying emergency processes in energy conversion pulse systems

2015 ◽  
Vol 11 (2) ◽  
pp. 74-79
Author(s):  
Dmitry O Tey ◽  
Artem V Gusakov ◽  
Nizam D Keramov
Keyword(s):  
Fourier Transform ◽  
Energy Conversion ◽  
Real Time ◽  
Pulse Energy ◽  
Sampling Rate ◽  
The State ◽  
Main Process ◽  
State Identification ◽  
Conversion System ◽  
Energy Conversion System

The article discusses the problem of identification of the state of the pulse energy conversion system in real time. Investigated a method of reducing the size and the sampling rate of data describing the state of the system wavelet transform, for applying a Fourier transform. Proposed and experimentally tested the algorithm state identification pulse energy conversion system that allows you to determine in real time during the main process of energy conversion

An efficient solution for fast generation of multi-GNSS real-time products

2021 ◽  
Author(s):  
Hongjie Zheng ◽  
Hanyu Chang ◽  
Yongqiang Yuan ◽  
Qingyun Wang ◽  
Yuhao Li ◽  
...  
Keyword(s):  
Data Processing ◽  
Real Time ◽  
Processing Time ◽  
Efficient Solution ◽  
Gpu Computing ◽  
Sampling Rate ◽  
Precise Orbit Determination ◽  
Processing Unit ◽  
Processing Efficiency ◽  
Central Processing

<p>Global navigation satellite systems (GNSS) have been playing an indispensable role in providing positioning, navigation and timing (PNT) services to global users. Over the past few years, GNSS have been rapidly developed with abundant networks, modern constellations, and multi-frequency observations. To take full advantages of multi-constellation and multi-frequency GNSS, several new mathematic models have been developed such as multi-frequency ambiguity resolution (AR) and the uncombined data processing with raw observations. In addition, new GNSS products including the uncalibrated phase delay (UPD), the observable signal bias (OSB), and the integer recovery clock (IRC) have been generated and provided by analysis centers to support advanced GNSS applications.</p><p>       However, the increasing number of GNSS observations raises a great challenge to the fast generation of multi-constellation and multi-frequency products. In this study, we proposed an efficient solution to realize the fast updating of multi-GNSS real-time products by making full use of the advanced computing techniques. Firstly, instead of the traditional vector operations, the “level-3 operations” (matrix by matrix) of Basic Liner Algebra Subprograms (BLAS) is used as much as possible in the Least Square (LSQ) processing, which can improve the efficiency due to the central processing unit (CPU) optimization and faster memory data transmission. Furthermore, most steps of multi-GNSS data processing are transformed from serial mode to parallel mode to take advantage of the multi-core CPU architecture and graphics processing unit (GPU) computing resources. Moreover, we choose the OpenBLAS library for matrix computation as it has good performances in parallel environment.</p><p>       The proposed method is then validated on a 3.30 GHz AMD CPU with 6 cores. The result demonstrates that the proposed method can substantially improve the processing efficiency for multi-GNSS product generation. For the precise orbit determination (POD) solution with 150 ground stations and 128 satellites (GPS/BDS/Galileo/GLONASS/QZSS) in ionosphere-free (IF) mode, the processing time can be shortened from 50 to 10 minutes, which can guarantee the hourly updating of multi-GNSS ultra-rapid orbit products. The processing time of uncombined POD can also be reduced by about 80%. Meanwhile, the multi-GNSS real-time clock products can be easily generated in 5 seconds or even higher sampling rate. In addition, the processing efficiency of UPD and OSB products can also be increased by 4-6 times.</p>

Real-time spectral interleaved electro-optic dual-comb spectroscopy

2020 ◽  
Author(s):  
Bingxin Xu ◽  
Xinyu Fan ◽  
Shuai Wang ◽  
Zuyuan He
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Figure Of Merit ◽  
Frequency Comb ◽  
Sampling Rate ◽  
Optical Metrology ◽  
Broad Bandwidth ◽  
Frequency Combs ◽  
Electro Optic ◽  
Spectral Sampling

Abstract Optical frequency comb with evenly spaced lines over a broad bandwidth has revolutionized the fields of optical metrology and spectroscopy. Here, we propose an electro-optic dual-comb spectroscopy to real-time interleave the spectrum with high resolution, in which two electro-optic frequency combs are seed by swept light source. An interleaved spectrum with a high resolution is real-time recorded by the sweeping probe comb without gap time, which is multi-heterodyne detected by the sweeping local comb. The proposed scheme measures a spectrum spanning 304 GHz in 1.6 ms with a resolution of 1 MHz, and reaches a spectral sampling rate of 1.9*108 points/s under Nyquist-limitation. A reflectance spectrum is measured with a calculated figure-of-merit of 4.2*108, which shows great prospect for fast and high-resolution applications.

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