Pulsed dipolar spectroscopy (PDS) is a powerful tool to explore conformational changes of membrane proteins (MPs). However, the MPs suffer from relatively weak dipolar signals due to their complex nature in membrane environments, which consequently reduces the interspin distance resolution obtainable by PDS. Here we report the use of nanodiscs (NDs) to improve the distance resolution. Two genetically engineered membrane scaffold protein mutants are introduced, each of which is shown to form double-labeled ND efficiently and with high homogeneity. The resultant interspin distance distribution is featured by a small distribution width, suggesting high resolution. When PDS is performed on a binary mixture of the double-labeled ND devoid of MPs and the un-labeled ND with incorporated double-labeled MPs, the overall amplitude of dipolar signals is increased, leading to a critical enhancement of the distance resolution. A theoretical foundation is provided to validate the analysis. With this approach, the determination of MP structures can be studied at high resolution in NDs.
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http://dx.doi.org/10.1039/c9ra00896a | DOI Listing |
Sensors (Basel)
January 2025
Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20878, USA.
Terrestrial laser scanners (TLS) are portable dimensional measurement instruments used to obtain 3D point clouds of objects in a scene. While TLSs do not require the use of cooperative targets, they are sometimes placed in a scene to fuse or compare data from different instruments or data from the same instrument but from different positions. A contrast target is an example of such a target; it consists of alternating black/white squares that can be printed using a laser printer.
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January 2025
Faculty of Science and Engineering, Saga University, Saga 840-8502, Japan.
Infrared array sensor-based fall detection and activity recognition systems have gained momentum as promising solutions for enhancing healthcare monitoring and safety in various environments. Unlike camera-based systems, which can be privacy-intrusive, IR array sensors offer a non-invasive, reliable approach for fall detection and activity recognition while preserving privacy. This work proposes a novel method to distinguish between normal motion and fall incidents by analyzing thermal patterns captured by infrared array sensors.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Chemistry and Institute of Nanotechnology and Advanced Materials, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Ctr1 is a membrane-spanning homotrimer that facilitates copper uptake in eukaryotic cells with high affinity. While structural details of the transmembrane domain of human Ctr1 have been elucidated using X-ray crystallography and cryo-EM, the transfer mechanisms of copper and the conformational changes that control the gating mechanism remain poorly understood. The role of the extracellular N-terminal domains is particularly unclear due to the absence of a high-resolution structure of the full-length hCtr1 protein and limited biochemical and biophysical characterization of the transporter in solution and in cell.
View Article and Find Full Text PDFIndian J Ophthalmol
February 2025
Orbit and Oculoplasty, Aravind Eye Hospital, Thavalakuppam, Pondicherry, India.
Purpose: The primary objective of this study was to investigate the possible role and assess the potential relationship of speculum use during phacoemulsification surgery in the occurrence of blepharoptosis.
Methods: Our study is a prospective observational design to analyze patients who underwent phacoemulsification surgery under topical anesthesia between October 2017 and May 2018 at a tertiary eye hospital in South India. All patients had their Margin Reflex Distance 1 (MRD1), levator palpebrae superioris (LPS) function, and lid crease distance (LCD) measured before and after surgery on day one, one month, three months, and six months to evaluate the extent of ptosis at each time point that was recorded clinically and photographic documentation for accurate evaluation.
Biosensors (Basel)
January 2025
Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
Hyperspectral imaging (HSI) technology, which offers both spatial and spectral information, holds significant potential for enhancing diagnostic performance during endoscopy and other medical procedures. However, quantitative evaluation of HSI cameras is challenging due to various influencing factors (e.g.
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