There is widespread concern about the safety of COVID-19 vaccinations related to platelet hyperactivity. However, their long-term influence on platelet activity remains unknown. We address this issue by applying a high-speed bright-field microscope based on optical frequency-division multiplexing and microfluidics for massive image-based analysis. We performed image-based single-cell profiling and temporal monitoring of circulating platelet aggregates in the blood samples of healthy human participants before and after they received three vaccination doses over a nearly one-year period. The results demonstrate no significant or persistent change in platelet activity after vaccine doses.
High-speed broadband Raman spectroscopy (>1000 cm^−1 bandwidth) provides label-free molecular vibrational information with fine temporal resolution, making it valuable for biomedical applications such as vibrational imaging or detecting transient molecular dynamics. Current techniques for high-speed broadband Raman spectroscopy, such as Fourier-transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy, can probe the Raman “fingerprint” region (500-1800 cm^−1), but lack sensitivity in the low-frequency or THz region (<200 cm^−1, <6 THz), preventing measurement of rich intermolecular vibrational information. Here we demonstrate a technique combining FT-CARS spectroscopy-like optical filtering with Sagnac interferometry for simultaneous acquisition of THz and fingerprint Raman spectra at 24,000 spectra/sec.
KEYWORDS: Raman spectroscopy, Raman scattering, Spectroscopy, Chemical analysis, Signal to noise ratio, Intelligence systems, Biological research, Chemistry, Biology, Medicine
By virtue of its chemical specificity and label-free nature, Raman spectroscopy is a ubiquitous tool in analytical chemistry which has recently found increasing interest in biology and medicine, as technical improvements steadily enable applications. In particular, the low-frequency region of the Raman spectrum, which contains rich information about intermolecular interactions and higher-order structure, has promise for biological applications. However, detection of low-frequency modes remains a challenge with conventional techniques for Raman spectroscopy. Here, we propose and experimentally demonstrate Sagnac-enhanced impulsive stimulated Raman scattering (SE-ISRS), a method for time-domain Raman spectroscopy that provides highly sensitive low-frequency Raman spectra at all probe frequencies.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.