Publications by authors named "Oscar Urquidi"
Natural Killer (NK) cells are pivotal in immune responses to viral infections, malignancies, autoimmune diseases, and transplantation. Assessment of NK cell adhesion, migration, and cytotoxicity is fundamental for in vitro studies. We propose a novel live-cell tracking method that addresses these three major aspects of NK cell function using human NK cells and primary porcine aortic endothelial cells (PAECs) in two-dimensional (2D) static assays and an in-house cylindrical 3D microfluidic system.
View Article and Find Full Text PDFCorrelation functions are nowadays routinely computed using time-tagged photon information instead of a hardware autocorrelator. The algorithm developed by Laurence et al. [Opt.
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- Morphology plays a crucial role in determining function, but studying its formation at the molecular level is complex due to the random nature of nanoscale events.
- New in situ/in vivo optical spectroscopy tools are being developed to address these challenges, which are non-invasive and do not require labeling.
- This text discusses how these innovative optical spectroscopy techniques can effectively aid in understanding the initial stages of morphology development.
Dynamic light scattering (DLS) is a widely applied technique in multiple scientific and industrial fields for the size characterization of nanoscale objects in solution. While DLS is typically applied to characterize systems under static conditions, the emerging interest in using DLS on temporally evolving systems stimulates the latent need to improve the time resolution of measurements. Herein, we present a DLS microscopy setup (micro-DLS) that can accurately characterize the size of particles from autocorrelation functions built from sub-100 ms time windows, several orders of magnitude faster than previously reported.
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- The study focuses on the biomineralisation of barite in the freshwater alga Spirogyra, aiming to understand how its microcrystals form and their potential use in reconstructing paleoproductivity.
- Observations with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS) indicate that the size and number of barite crystals vary with barium concentration, and crystals exhibit a unique morphology influenced by organic molecules.
- In vivo experiments reveal that these microcrystals are formed in the cytoplasm, with barium and sulfate available as a result of cellular processes and serve roles in both actin polymerisation and amino acid biosynthesis.
Reply to Liao and Wynne: The size of crystal nucleus remains an open question.
Proc Natl Acad Sci U S A
August 2022
In situ optical spectroscopy of crystallization: One crystal nucleation at a time.
Proc Natl Acad Sci U S A
April 2022
While crystallization is a ubiquitous and an important process, the microscopic picture of crystal nucleation is yet to be established. Recent studies suggest that the nucleation process can be more complex than the view offered by the classical nucleation theory. Here, we implement single crystal nucleation spectroscopy (SCNS) by combining Raman microspectroscopy and optical trapping induced crystallization to spectroscopically investigate one crystal nucleation at a time.
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