SAR Assessment Using Vector Probe Array System in the Context of RF Exposure Reduction Utilising Proximity Sensors and Time-Averaging Technologies

The increased resistance of bacteria against conventional pharmaceutical solutions, the antibiotics, has raised serious health concerns. This has stimulated interest in the development of bio-based therapeutics with limited resistance, namely, essential oils (EOs) or antimicrobial peptides (AMPs). This study envisaged the evaluation of the antimicrobial efficacy of selected biomolecules, namely LL37, pexiganan, tea tree oil (TTO), cinnamon leaf oil (CLO) and niaouli oil (NO), against four bacteria commonly associated to nosocomial infections: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa. The antibiotic vancomycin and silver nanoparticles (AgNPs) were used as control compounds for comparison purposes. The biomolecules were initially screened for their antibacterial efficacy using the agar-diffusion test, followed by the determination of minimal inhibitory concentrations (MICs), kill-time kinetics and the evaluation of the cell morphology upon 24 h exposure. All agents were effective against the selected bacteria. Interestingly, the AgNPs required a higher concentration (4000–1250 μg/mL) to induce the same effects as the AMPs (500–7.8 μg/mL) or EOs (365.2–19.7 μg/mL). Pexiganan and CLO were the most effective biomolecules, requiring lower concentrations to kill both Gram-positive and Gram-negative bacteria (62.5–7.8 μg/mL and 39.3–19.7 μg/mL, respectively), within a short period of time (averaging 2 h 15 min for all bacteria). Most biomolecules apparently disrupted the bacteria membrane stability due to the observed cell morphology deformation and by effecting on the intracellular space. AMPs were observed to induce morphological deformations and cellular content release, while EOs were seen to split and completely envelope bacteria. Data unraveled more of the potential of these new biomolecules as replacements for the conventional antibiotics and allowed us to take a step forward in the understanding of their mechanisms of action against infection-related bacteria.

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Evaluation of Cell Membrane Effects After 3D Multicellular Spheroids RF Exposure

2020 IEEE MTT-S International Microwave Biomedical Conference (IMBioC) ◽

10.1109/imbioc47321.2020.9385011 ◽

2020 ◽

Author(s):

Jelena Kolosnjaj-Tabi ◽

Geraldine Alberola ◽

Sylvain Auge ◽

Amar Tamra ◽

David Dubuc ◽

...

Keyword(s):

Cell Membrane ◽

Multicellular Spheroids ◽

Rf Exposure ◽

Membrane Effects

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Development of a thin high-frequency and high-precision magnetic probe array in Sino-United Spherical Tokamak

Review of Scientific Instruments ◽

10.1063/5.0043631 ◽

2021 ◽

Vol 92 (5) ◽

pp. 053518

Author(s):

Zhengbo Cheng ◽

Yi Tan ◽

Zhe Gao ◽

Shouzhi Wang ◽

Binbin Wang ◽

...

Keyword(s):

High Precision ◽

High Frequency ◽

Magnetic Probe ◽

Spherical Tokamak ◽

Probe Array

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Improving Air Pollutant Metal Oxide Sensor Quantification Practices through: An Exploration of Sensor Signal Normalization, Multi-Sensor and Universal Calibration Model Generation, and Physical Factors Such as Co-Location Duration and Sensor Age

Atmosphere ◽

10.3390/atmos12050645 ◽

2021 ◽

Vol 12 (5) ◽

pp. 645

Author(s):

Kristen Okorn ◽

Michael Hannigan

Keyword(s):

Metal Oxide ◽

Low Cost ◽

Air Pollutant ◽

Sensor System ◽

Physical Factors ◽

Time Averaging ◽

Calibration Model ◽

Sensor Signal ◽

Metal Oxide Sensors ◽

Signal Normalization

As low-cost sensors have become ubiquitous in air quality measurements, there is a need for more efficient calibration and quantification practices. Here, we deploy stationary low-cost monitors in Colorado and Southern California near oil and gas facilities, focusing our analysis on methane and ozone concentration measurement using metal oxide sensors. In comparing different sensor signal normalization techniques, we propose a z-scoring standardization approach to normalize all sensor signals, making our calibration results more easily transferable among sensor packages. We also attempt several different physical co-location schemes, and explore several calibration models in which only one sensor system needs to be co-located with a reference instrument, and can be used to calibrate the rest of the fleet of sensor systems. This approach greatly reduces the time and effort involved in field normalization without compromising goodness of fit of the calibration model to a significant extent. We also explore other factors affecting the performance of the sensor system quantification method, including the use of different reference instruments, duration of co-location, time averaging, transferability between different physical environments, and the age of metal oxide sensors. Our focus on methane and stationary monitors, in addition to the z-scoring standardization approach, has broad applications in low-cost sensor calibration and utility.

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On the use of 3J-coupling NMR data to derive structural information on proteins

Journal of Biomolecular NMR ◽

10.1007/s10858-020-00355-5 ◽

2021 ◽

Vol 75 (1) ◽

pp. 39-70

Author(s):

Lorna J. Smith ◽

Wilfred F. van Gunsteren ◽

Bartosz Stankiewicz ◽

Niels Hansen

Keyword(s):

Protein Structure ◽

Structural Information ◽

Protein Structure Determination ◽

High Sensitivity ◽

Time Averaging ◽

Conformational Ensemble ◽

Torsional Angle ◽

Conformational Variability ◽

Egg White Lysozyme ◽

Coupling Time

AbstractValues of 3J-couplings as obtained from NMR experiments on proteins cannot easily be used to determine protein structure due to the difficulty of accounting for the high sensitivity of intermediate 3J-coupling values (4–8 Hz) to the averaging period that must cover the conformational variability of the torsional angle related to the 3J-coupling, and due to the difficulty of handling the multiple-valued character of the inverse Karplus relation between torsional angle and 3J-coupling. Both problems can be solved by using 3J-coupling time-averaging local-elevation restraining MD simulation. Application to the protein hen egg white lysozyme using 213 backbone and side-chain 3J-coupling restraints shows that a conformational ensemble compatible with the experimental data can be obtained using this technique, and that accounting for averaging and the ability of the algorithm to escape from local minima for the torsional angle induced by the Karplus relation, are essential for a comprehensive use of 3J-coupling data in protein structure determination.

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Investigation of Impact Profile and Isolation Effect in Automated Impact Device Design and Control for Operational Modal Analysis

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4030526 ◽

2015 ◽

Vol 137 (9) ◽

Cited By ~ 5

Author(s):

Z. C. Ong ◽

C. C. Lee

Keyword(s):

Modal Analysis ◽

Isolation Effect ◽

Time Averaging ◽

Impact Device ◽

Lack Of Information ◽

Analysis Technique ◽

And Control ◽

Phase Angles ◽

Synchronous Time

A novel modal analysis technique called impact-synchronous modal analysis (ISMA) was introduced in previous research. With the utilization of impact-synchronous time averaging (ISTA), this modal analysis can be performed in presence of ambient forces whereas the conventional analysis method requires machines to be totally shut down. However, lack of information of phase angles with respect to impact in ISMA has caused it to be labor-intensive and time-consuming. An automated impact device (AID) is introduced in this study in the effort to replace the manually operated impact hammer and prepare it to be used in the current practice of ISMA on the purpose of enhancing its effectiveness and practicability. Impact profile and isolation effect are noted to be the contributing parameters in this study. This paper devoted on calibrating and controlling of the AID which gives the desired impact profiles as compared to the manual impact hammer. The AID is found effective in the determination of dynamic characteristics when the device is isolated from the boundary condition of the test structure.

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