In vitro effect of some nucleoside reverse transcriptase inhibitors against HSV-1 replication.

OBJECTIVE: The current study was designed to investigate the effects of some nucleoside reverse transcriptase inhibitors (NRTIs) on HSV-1 infection. MATERIALS AND METHODS: Initially, the SwissTargetPrediction server was used to predict the interactions between HSV-1 thymidine kinase and acyclovir, stavudine, zidovudine, didanosine, and entecavir. The effect of each component on Vero cell viability was assessed by the MTT assay. After treatment, the cell supernatants were collected, and HSV-1 replication was analyzed by quantitative real-time PCR. RESULTS: The qPCR results revealed that viral titers were reduced 41, 40, 19, 44, and 31-fold in the presence of acyclovir, zidovudine, stavudine, didanosine, and entecavir, respectively. CONCLUSIONS: Our findings indicate that NRTIs significantly reduce HSV-1 replication in cell culture.

Mechanical tuning of whispering gallery modes over a 0.5 THz tuning range with MHz resolution in a silica microsphere at cryogenic temperatures.

We experimentally demonstrate the mechanical tuning of whispering gallery modes in a 40 µm diameter silica microsphere at 10K, over a tuning range of 450 GHz and with a resolution less than 10 MHz. This is achieved by mechanically stretching the stems of a double-stemmed silica microsphere with a commercially available piezo-driven nano-positioner. The large tuning range is made possible by the millimeter long slip-stick motion of the nano-positioner. The ultrafine tuning resolution, corresponding to sub-picometer changes in the sphere diameter, is enabled by the use of relatively long and thin fiber stems, which reduces the effective Poisson ratio of the combined sphere-stem system to approximately 0.0005. The mechanical tuning demonstrated here removes a major obstacle for the use of ultrahigh Q-factor silica microspheres in cavity QED studies of solid state systems and, in particular, cavity QED studies of nitrogen vacancy centers in diamond.

A composite microcavity of diamond nanopillar and deformed silica microsphere with enhanced evanescent decay length.

We report the experimental realization of a composite microcavity system, in which negatively-charged nitrogen vacancy (NV) centers in diamond nanopillars couple evanescently to whispering-gallery modes (WGMs) in a deformed, non-axisymmetric silica microsphere. We show that the deformed microsphere can feature an evanescent decay length four times larger than that of a regular silica microsphere. With the enhanced evanescent coupling, WGMs can in principle couple to NV centers that are 100 to 200 nm beneath the diamond pillar surface, providing a promising avenue for exploring evanescently-coupled cavity QED systems of NV centers in ultrahigh purity diamond.