The use of fluorescent compounds as biological markers or probes is widely used in assays for probing various properties, including but not limited to pH, temperature, or the presence of various proteins. This has allowed fluorescence to enter the fields of microscopy, diagnostics, and spectroscopy. Among the many dyes used for such applications are those that exhibit phosphorescence. Unlike fluorescence, which has a lifetime of several nanoseconds, phosphorescence lifetimes can be several seconds, allowing for the use of techniques such as gated detection, which can eliminate distracting background noise or Raman scattering. Since phosphorescence uses the triplet state rather than the singlet state, it requires less energy, which correlates with longer wavelengths. The phosphorescence emission of some dyes can extend from 425nm (blue) to 675nm (red), which encompasses almost the entire visible spectrum. This is especially useful when considering that longer wavelengths may be used when utilizing direct triplet state excitation, which allows for excitation wavelengths well into the visible range. The ability to utilize longer excitation wavelengths has numerous possibilities, among which include being safe to use with live cells, which opens the door for using phosphorescence as a technique for biological imaging. Not only does phosphorescence allow imaging to occur at longer wavelengths, which mitigates damage to cells and minimizes exposure to harmful ultraviolet radiation, but it also allows for much more affordable equipment and procedures, possibly making diagnostic care more accessible.

Multipartite viruses are a unique class of viruses that divide their genome into multiple segments, each packaged into a separate viral particle. Unlike traditional viruses, which encapsulate their entire genome within a single particle, multipartite viruses require all genome segments to infect the same host cell for successful replication. This study investigates the infection dynamics of multipartite viruses through mathematical modeling, with a focus on bipartite and tripartite viruses. By comparing their behavior to single-particle viruses, we analyze the factors influencing viral persistence and spread. Our results indicate that the higher number of particles in a virus, the harder it is to maintain an infection. While multipartite infections exhibit shorter durations of infections compared to single-particle infections, their ability to persist suggests a potential benefit. These findings can help develop an understanding into the adaptive mechanisms of multipartite viruses and contribute to a broader understanding of viral evolution and host-virus interactions.

Surface plasmon–coupled emission (SPCE) is a powerful phenomenon that utilizes the near-field interaction between excited fluorophores and thin metallic films, together with a glass substrate, to significantly improve fluorescence detection sensitivity. By coupling the fluorophore’s oscillating dipole to surface plasmons, SPCE channels a substantial fraction of the emitted photons into a defined angle, generating a highly directional and polarized emission that can achieve up to 50% light collection efficiency. This intrinsically wavelength-resolved emission not only simplifies optical system design but also elevates the signal-to-noise ratio by reducing background interference. Compared to conventional isotropic free-space fluorescence, SPCE’s strong directional control and enhanced collection enable the detection of analytes at extremely low limits. Hence, this paper elucidates how SPCE’s unique advantages can be leveraged to achieve highly sensitive detection of critical biomarkers, paving the way for more rapid and efficient diagnostic applications.

Micro- and nanoscale metal oxides are used in a variety of applications. ZnO and Ga2O3 semiconductors are two metal oxides that have a wide bandgap and find themselves used in today’s electronics, gas sensors, and photodetectors. These two materials are also used in a wide range of temperatures, which means that the chemical bond lengths, vibrational states, defect states, and band-gaps all should be variable. In our experiments, we investigate the T-dependencies of positions, intensities, and widths of Raman peaks/bands for micro- and nanoscale ZnO and Ga2O3. In our studies, in addition to the temperature-dependent Raman spectroscopy we employ scanning electron microscopy (morphology of particles), energy dispersive X-ray spectroscopy (stochiometry) and temperature-dependent photoluminescence spectroscopy (electronic structure).

Human Immunodeficiency Virus (HIV) can exist as syncytia-forming or non-syncytia-forming strains, each utilizing different mechanisms of infection. Understanding the competition between these strains is crucial, as syncytia formation has been linked to increased disease progression and immune system decline. This study develops a mathematical model to analyze their competition, incorporating parameters such as fusion rate, syncytia lifespan, and viral production. Stability analysis and simulations will determine conditions under which one strain dominates or both coexist. By varying key parameters, we aim to understand how syncytia formation influences viral dynamics and infection persistence, providing insights into HIV pathogenesis and potential treatment strategies.