scholarly journals A precise and general FRET-based method for monitoring structural transitions in protein self-organization

2021 ◽  
Author(s):  
Qi Wan ◽  
Sara N. Mouton ◽  
Liesbeth M. Veenhoff ◽  
Arnold J. Boersma
Keyword(s):  
Continuous Monitoring ◽  
High Sensitivity ◽  
Structural Transitions ◽  
Spatiotemporal Resolution ◽  
Native Proteins ◽  
Donor And Acceptor ◽  
Ratiometric Imaging ◽  
Transient Intermediate ◽  
Insight Into ◽  
High Throughput Manner

AbstractProteins assemble into a tremendous variety of dynamic and functional structures. Sensitive measurements directly in cells with a high spatiotemporal resolution are needed to distinguish these different assemblies. Here, we demonstrate precise and continuous monitoring of cytoplasmic protein self-assemblies and their structural transitions. Intermolecular FRET with both the donor and acceptor protein at the same target protein provides high sensitivity while retaining the advantage of straightforward ratiometric imaging. We measure different assembly structures, transient intermediate states’ kinetics, and assembly formation resolved in space and time. Specifically, the method recapitulates that i) the mutant Huntingtin exon1 (mHttex1) protein first forms low-FRET and presumably less ordered assemblies in yeast and human cells, which develop into high-FRET aggregates, ii) the chaperone DNAJB6b prevents low-FRET mHttex1 assemblies, yet coassembles with mHttex1 aggregates, and iii) FUS’ condensates have mutation-dependent nanoscopic structures. FACS measurements allow assembly measurement in a high-throughput manner crucial for screening efforts, while fluorescence microscopy provides spatiotemporally-resolved measurements on the single-condensate level during a cell’s lifetime to assess the biological consequences. Implementation in other native or non-native proteins could provide insight into many studies involving protein condensation or aggregation.

scholarly journals High Sensitivity Continuous Monitoring of Chloroform Gas by Using Wavelength Modulation Photoacoustic Spectroscopy in the Near-Infrared Range

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Continuous Monitoring ◽  
Near Infrared ◽  
Resonant Cavity ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Infrared Range ◽  
Wavelength Modulation ◽  
Linear Coefficient

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.

Studies on the Toxicity of Aromatic Hydrocarbons on Chorella Vulgaris by 3D-QSAR Using CoMFA and CoMSIA Methods

2012 ◽  
Vol 610-613 ◽  
pp. 3574-3579
Author(s):  
Cui Hua Wang ◽  
Sheng Long Yang ◽  
Chao Lu ◽  
Hong Xia Yu ◽  
Lian Shen Wang ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Aromatic Hydrocarbons ◽  
Common Factor ◽  
3D Qsar ◽  
The Other ◽  
Contour Maps ◽  
Substituent Group ◽  
Donor And Acceptor ◽  
The Common ◽  
Insight Into

By using CoMFA and CoMSIA methods, the new quantitative structures of 25 aromatic hydrocarbons and the 96 hr-EC50 data with C. vulgaris have been investigated to obtain more detailed insight into the relationships between molecular structure and bioactivity. Compared to CoMFA (the average Q2LOO option =0.610), CoMSIA (the average Q2LOO =0.736) has the better results with robustness and stability. CoMSIA analysis using steric, electrostatic, hydrophobic, and H-bond donor and acceptor descriptors show H-bond donor is the common factor for influencing the toxicity, the steric and electrostatic descriptors are next and the hydrophobic descriptor was last. From the contour maps, the number of benzene ring is more crucial for the compound toxicity and the compounds with more benzene ring make toxicity increased. Under the same number of benzene ring, the kind of substituent group and the formed ability of H-bond are the other parameters to influencing the aromatic hydrocarbons toxicity.

scholarly journals Novel glucose-responsive of the transparent nanofiber hydrogel patches as a wearable biosensor via electrospinning

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gun Jin Kim ◽  
Kyu Oh Kim
Keyword(s):  
Continuous Monitoring ◽  
Interstitial Fluid ◽  
High Sensitivity ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
High Permeability ◽  
Reverse Iontophoresis ◽  
Glucose Levels ◽  
Non Invasive ◽  
High Enzyme

Abstract Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. However, the high crystallinity of NFs limits the achievement of transparency via electrospinning. Transparent poly(vinyl alcohol)/β-cyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. We designed the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogels, which exhibit flexibility, biocompatibility, excellent absorptivity (DI water: 21.9 ± 1.9, PBS: 41.91 ± 3.4), good mechanical properties (dried: 12.1 MPa, wetted: 5.33 MPa), and high enzyme activity of 76.3%. Owing to the unique features of PVA/β-CD/GOx containing AuNPs NF hydrogels, such as high permeability to bio-substrates and rapid electron transfer, our biosensors demonstrate excellent sensing performance with a wide linear range, high sensitivity(47.2 μA mM−1), low sensing limit (0.01 mM), and rapid response time (< 15 s). The results indicate that the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogel patch sensor can measure the glucose concentration in human serum and holds massive potential for future clinical applications.

scholarly journals Formation and field-driven dynamics of nematic spheroids

Soft Matter ◽  
2017 ◽  
Vol 13 (28) ◽  
pp. 4890-4902 ◽  
Author(s):  
Fred Fu ◽  
Nasser Mohieddin Abukhdeir
Keyword(s):  
External Field ◽  
Phase Formation ◽  
Structural Transitions ◽  
Complex Interplay ◽  
Switching Dynamics ◽  
Insight Into

Simulations of phase formation and external field-driven switching dynamics of micron-scale nematic spheroids provide insight into the complex interplay between nanoscale defect dynamics and macroscale structural transitions.

scholarly journals A critical insight into the development pipeline of microfluidic immunoassay devices for the sensitive quantitation of protein biomarkers at the point of care

The Analyst ◽  
2017 ◽  
Vol 142 (6) ◽  
pp. 858-882 ◽  
Author(s):  
Ana I. Barbosa ◽  
Nuno M. Reis
Keyword(s):  
Critical Review ◽  
Point Of Care ◽  
High Sensitivity ◽  
Protein Biomarkers ◽  
Sensitivity Measurement ◽  
Microfluidic Immunoassay ◽  
Development Pipeline ◽  
Critical Insight ◽  
Insight Into

A critical review on the development of microfluidic tests capable of the high-sensitivity measurement of protein biomarkers at the point-of-care.

Spectroscopic Determination of C2 Densities in AR/H 2/CH 4 and AR/H2/C60 Microwave Plasmas For Nanocrystalline Diamond Synthesis

1997 ◽  
Vol 502 ◽  
Author(s):  
A. N. Goyette ◽  
J. E. Lawler ◽  
L. W. Anderson ◽  
D. M. Gruen ◽  
T. G. Mccauley ◽  
...  
Keyword(s):  
Gas Phase ◽  
Diamond Films ◽  
High Sensitivity ◽  
Nanocrystalline Diamond ◽  
Chamber Pressure ◽  
Diamond Synthesis ◽  
Microwave Plasmas ◽  
State Concentration ◽  
Insight Into

ABSTRACTWe have measured the steady state concentration of gas phase C2 in Ar/H2/CH4 and Ar/H2/C60 microwave plasmas used for the deposition of nanocrystalline diamond films. High sensitivity white light absorption spectroscopy is used to monitor the C2 density using the d 3 Π ← a3Π (0,0) vibrational band of C2 as chamber pressure, microwave power, substrate temperature and feed gas mixtures are varied in both chemistries. Understanding how these parameters influence the C2 density in the plasma volume provides insight into discharge mechanisms relevant to the deposition of nanocrystalline diamond.

scholarly journals The observed thermal anomaly as an earthquake Precursor: A case study from the 1993 Latur earthquake prone area in Western India

2021 ◽  
Author(s):  
Vijay P Dimri ◽  
Simanchal Padhy ◽  
N C Mondal ◽  
G K Reddy ◽  
G G. Ramacharyulu ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Seismic Hazard Assessment ◽  
Thermal Anomaly ◽  
Atmospheric Temperature ◽  
Research Area ◽  
Earthquake Precursor ◽  
Western India ◽  
Monsoon Period ◽  
Prone Area ◽  
Insight Into

Abstract We report and discuss monitoring of short-term variations of widely used multi-geophysical parameters in Latur-Killari area in western India, the region that witnessed a major devastating earthquake in 1993. An abnormal rise in atmospheric temperature of more than 20°C at 11200 m height was observed in the air-flight just 100 km away from Latur during a monsoon period. We investigated the cause of such abnormal rise in temperature in relation to the seismicity of the area for the 1993 Latur earthquake along with the continuous monitoring of ground water level and soil Helium gas for a week under a precursory 'quick please' operation in the study area. There were no seismic signals associated with this precursor rise that led to the suspension of the operation after a week time. It is also observed that this thermal anomaly is not followed by any major earthquake over the area, which has larger implications in atmosphere research area, suggesting a detailed investigation of such anomaly that may provide a better insight into the precursory behavior of the observed thermal anomaly by overcoming the constraints of accurate retrieval of temperature due to inadequate penetration of Satellite based thermal sensor into thick clouds. Findings of this study certainly call for continuous monitoring of temperature over the earthquake prone areas to gain insight into the physics of short-lived variation in temperature over spatially limited extent, especially over the earthquake prone areas for improved seismic hazard assessment.

scholarly journals The Bacterial Pneumonia Characteristics based on Climate and Meteorological Parameters in Indonesia, the Tropical Country: A Preliminary Study

2021 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Bramantono Bramantono ◽  
Brian Eka Rachman ◽  
Erika Marfiani ◽  
Neneng Dewi Kurniati ◽  
Muhammad Vitanata Arifijanto ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antibiotic Sensitivity ◽  
High Sensitivity ◽  
Surveillance Period ◽  
Acinetobacter Baumanii ◽  
Tropical Country ◽  
Dry Seasons ◽  
Preliminary Study ◽  
Bacterial Patterns ◽  
Insight Into

Introduction: As a tropical country, Indonesia has the potential to influence the characteristics of infectious diseases. The purpose of this study was to see how the pattern of pneumonia on various weather components such as rainfall, humidity, and temperature.Methods: This study was carried by retrospective screening in the infectious ward in one of the tertiary referral hospitals.Results: A total of 876 cases of pneumonia from eight treatment rooms were included in the study. The highest pneumonia cases occurred in February with 239 (27.2%) cases followed in April and May with 169 (19.2%) and 159 (18.2%) cases respectively. After microbiological examination, bacterial growth was found in 191 cases. The highest number of bacteria was found in February with 62 (32%), followed by May with 33 (17.2%) and April with 31 (16.2%) samples. Most of the bacterial grown were gram-negative (94.3%), dominated by Klebsiella pneumoniae (35%), followed by Acinetobacter baumanii 17.2%  and Pseudomonas aeruginosa  12%. On the examination of antibiotic sensitivity, it was found that amikacin has a consistently high sensitivity (90%) for pneumonia caused by most bacterial causes (Acinetobacter baumanii, Klebsiella pneumoniae, and Escherichia coli).Conclusion: The study did not show any remarkable bacterial patterns based on weather components such as rainfall, humidity, and temperature during the rainy season. However, increasing the surveillance period will provide a better insight into the bacterial pattern and can compare it in the rainy and dry seasons.

What vibrations tell us about GTPases

2015 ◽  
Vol 396 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Carsten Kötting ◽  
Klaus Gerwert
Keyword(s):  
Small Gtpases ◽  
Small Gtpase ◽  
Attenuated Total Reflection ◽  
Transport Mechanisms ◽  
Spatiotemporal Resolution ◽  
Gtp Hydrolysis ◽  
Time Resolved ◽  
Gtpase Activating Proteins ◽  
Catalytic Mechanisms ◽  
Insight Into

Abstract In this review, we discuss how time-resolved Fourier transform infrared (FTIR) spectroscopy is used to understand how GTP hydrolysis is catalyzed by small GTPases and their cognate GTPase-activating proteins (GAPs). By interaction with small GTPases, GAPs regulate important signal transduction pathways and transport mechanisms in cells. The GTPase reaction terminates signaling and controls transport. Dysfunctions of GTP hydrolysis in these proteins are linked to serious diseases including cancer. Using FTIR, we resolved both the intrinsic and GAP-catalyzed GTPase reaction of the small GTPase Ras with high spatiotemporal resolution and atomic detail. This provided detailed insight into the order of events and how the active site is completed for catalysis. Comparisons of Ras with other small GTPases revealed conservation and variation in the catalytic mechanisms. The approach was extended to more nearly physiological conditions at a membrane. Interactions of membrane-anchored GTPases and their extraction from the membrane are studied using the attenuated total reflection (ATR) technique.

scholarly journals Scalable tactile sensor arrays on flexible substrates with high spatiotemporal resolution enabling slip and grip for closed-loop robotics

2020 ◽  
Vol 6 (46) ◽  
pp. eabd7795
Author(s):  
Hongseok Oh ◽  
Gyu-Chul Yi ◽  
Michael Yip ◽  
Shadi A. Dayeh
Keyword(s):  
Large Scale ◽  
Closed Loop ◽  
Sensor Arrays ◽  
High Sensitivity ◽  
Tactile Sensor ◽  
Flexible Substrates ◽  
Spatiotemporal Resolution ◽  
Reliable Performance ◽  
Device Applications ◽  
Flow Detection

We report large-scale and multiplexed tactile sensors with submillimeter-scale shear sensation and autonomous and real-time closed-loop grip adjustment. We leveraged dual-gate piezoelectric zinc oxide (ZnO) thin-film transistors (TFTs) fabricated on flexible substrates to record normal and shear forces with high sensitivity over a broad range of forces. An individual ZnO TFT can intrinsically sense, amplify, and multiplex force signals, allowing ease of scalability for multiplexing from hundreds of elements with 100-μm spatial and sub–10-ms temporal resolutions. Notably, exclusive feedback from the tactile sensor array enabled rapid adjustment of grip force to slip, enabling the direct autonomous robotic tactile perception with a single modality. For biomedical and implantable device applications, pulse sensing and underwater flow detection were demonstrated. This robust technology, with its reproducible and reliable performance, can be immediately translated for use in industrial and surgical robotics, neuroprosthetics, implantables, and beyond.

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