Validation of a Novel Fluorescent Lateral Flow Assay for Rapid Qualitative and Quantitative Assessment of Total Anti-SARS-CoV-2 S-RBD Binding Antibody Units (BAU) from Plasma or Fingerstick Whole-Blood of COVID-19 Vaccinees

Background: Limited commercial LFA assays are available to provide a reliable quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD). Aim: This study aimed to evaluate the performance of the fluorescence LFA FinecareTM 2019-nCoV S-RBD test along with its reader (Model No.: FS-113) against the following reference methods: (i) the FDA-approved GenScript surrogate virus-neutralizing assay (sVNT); and (ii) three highly performing automated immunoassays: BioMérieux VIDAS®3, Ortho VITROS®, and Mindray CL-900i®. Methods: Plasma from 488 vaccinees was tested by all aforementioned assays. Fingerstick whole-blood samples from 156 vaccinees were also tested by FinecareTM. Results and conclusions: FinecareTM showed 100% specificity, as none of the pre-pandemic samples tested positive. Equivalent FinecareTM results were observed among the samples taken from fingerstick or plasma (Pearson correlation r = 0.9, p < 0.0001), suggesting that fingerstick samples are sufficient to quantitate the S-RBD BAU/mL. A moderate correlation was observed between FinecareTM and sVNT (r = 0.5, p < 0.0001), indicating that FinecareTM can be used for rapid prediction of the neutralizing antibody (nAb) post-vaccination. FinecareTM BAU results showed strong correlation with VIDAS®3 (r = 0.6, p < 0.0001) and moderate correlation with VITROS® (r = 0.5, p < 0.0001) and CL-900i® (r = 0.4, p < 0.0001), suggesting that FinecareTM can be used as a surrogate for the advanced automated assays to measure S-RBD BAU/mL.This work was made possible by grant number UREP28-173-3-057 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors

Project Report at the ALPHA Collaboration – CERN Summer Student 2018

This report includes a summary of my overall work during my stay in the ALPHA experiment at CERN. I have been working and helping daily in ALPHA while running the experiment and assisting with building the new ALPHA-G experiment. Also, I had my side project which dealt with creating a PID controller for the beamline magnets

Mechanical and Corrosion Response of Friction Stir Extruded Magnesium Alloys

Magnesium (Mg) and its alloys are attractive candidates for lightweight applications owing to their high specific mechanical properties. These properties make magnesium comparable to many polymers in terms of weight while offering a higher strength. Also, Mg is a biocompatible metal that does not trigger toxicological tissue reactions since it exists naturally in the human body. Such capabilities of Mg make it an excellent candidate to be used in biomedical applications. However, Mg has low ductility at ambient temperature as a result of its hexagonal closed packed (HCP) crystal structure, which necessitates heat input to activate additional slip systems to promote stable flow and accommodate high strains. Therefore, Mg requires multi-stage high-temperature processing to achieve the desired form. In this context, this research utilizes Friction Stir Extrusion (FSE), a new solid-state process based on the principles of friction stir welding that uses frictional heat and severe plastic deformation to manufacture the metal into a rod in single-stage processing. WE43, an important Mg alloy, was selected as a model material in this study. WE43 is already being used in the transportation sector, such as in helicopter transmissions and aero-engines. Also, due to its proven biocompatibility, it has the potential to be utilized in biomedical devices. Yet, the precipitates nature in WE43 alloy creates a complex mechanical and corrosion response which makes it crucial to investigate and necessitates engineering its microstructure to achieve the desired behavior. The study aimed to understand the microstructural features that evolve due to the FSE and their corresponding effect on mechanical and corrosion behavior. FSE process produced a composite microstructure with refined grains in the outer region, while coarse grains were observed in the rod center. It is believed that this composite microstructure results due to the strain, strain rate, and temperature variations during the process. The composite microstructure significantly impacted the rod’s mechanical properties where the microhardness was higher towards the edge of the rod, while the core had lower hardness owing to larger grains. The mechanical properties were later studied by nano-, micro, and macro-scale mechanical tests. A relative comparison of the corrosion behavior showed that the corrosion rate of the rod increased as a result of the FSE process due to the variation in the grain size and the distribution of the precipitates in the different regions on the extruded rod. However, the corrosion resistance improved by removing the refined grains region from the rod and keeping only the rod’s core. This research provides a preliminary assessment of using FSE to produce Mg alloy rods for potential applications in biocompatible medical devices such as stents and dental implants