27 research outputs found
Measurements of absorption coefficient and refractive index changes without the KramersâKronig relation in photorefractive quantum wells of GaAs
SARS-CoV-2 infects the human kidney and drives fibrosis in kidney organoids
Kidney failure is frequently observed during and after COVID-19, but it remains elusive whether this is a direct effect of the virus. Here, we report that SARS-CoV-2 directly infects kidney cells and is associated with increased tubule-interstitial kidney fibrosis in patient autopsy samples. To study direct effects of the virus on the kidney independent of systemic effects of COVID-19, we infected human-induced pluripotent stem-cell-derived kidney organoids with SARS-CoV-2. Single-cell RNA sequencing indicated injury and dedifferentiation of infected cells with activation of profibrotic signaling pathways. Importantly, SARS-CoV-2 infection also led to increased collagen 1 protein expression in organoids. A SARS-CoV-2 protease inhibitor was able to ameliorate the infection of kidney cells by SARS-CoV-2. Our results suggest that SARS-CoV-2 can directly infect kidney cells and induce cell injury with subsequent fibrosis. These data could explain both acute kidney injury in COVID-19 patients and the development of chronic kidney disease in long COVID
Spectral holeburning properties of RⲠcolor centers in LiF: dependence on doping and irradiation processes
The effects of doping and radiation-damage processes on the persistent spectral hole burning properties of RⲠcolor centers in LiF were studied using current tuned GaAlAs diode-laser derivative spectroscopy. Dopants used were Mg, Ni and Co and irradiation was done by x-rays and neutrons. The holes were alwys burned near the center of the zerophonon line. In most cases the experimentally determined hole lineshapes including side holes could be satisfactorily fit by a phenomenological lineshape model with three adjustable parameters. The amplitudes of the side holes relative to the main hole were found to increase with increasing radiation damage. Š 1986 Springer-Verlag.This work was supported in part by the Office of Naval Research.Peer Reviewe