A large amount of kerf loss silicon slurries has been produced in the photovoltaics industry by direct diamond-wire slicing. The high-purity silicon particles in the slurries are suitable for reutilization as anode materials for lithium-ion batteries. In this study silicon particles from the kerf loss of silicon ingot slicing, coupled with lignin or lignocellulose as carbon precursors, are employed to form carbon–silicon composite materials. A pyrolysis thermal treatment in the presence of argon was applied to carbonize the biomass on the silicon materials in order to increase the conductivity of silicon-based anodes. Due to the different carbonaceous precursors, the composites formed different structures. The lignin-silicon electrode with a carbon-coated structure delivered an initial charge capacity of up to 2286 mAh/g and retained 880 mAh/g after 51 cycles at 300 mA/g. On the other hand, the pyrolyzed lignocellulose formed an interconnected structure with silicon particles, providing extra space to accommodate Si volume variation. The composite electrode exhibited an outstanding cycle performance with a capacity retention of up to 83.4% after 51 cycles at 300 mA/g. It was found that the utilization of silicon slurries from industrial silicon kerf loss and of biomass resources as battery materials can be improved and applied in energy storage application.

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SARS-CoV-2 infects humans through the binding of viral S-protein (spike protein) to human ACE2 (angiotensin I converting enzyme 2). The structure of the ACE2-S-protein complex has been deciphered and we focused on the 27 ACE2 residues that bind to S-protein. From human sequence databases, we identified 9 ACE2 variants at ACE2-S-protein binding sites. We used both experimental assays and protein structure analysis to evaluate the effect of each variant on the binding affinity of ACE2 to S-protein. We found one variant causing complete binding disruption, two and three variants, respectively, strongly and mildly reducing the binding affinity, and two variants strongly enhancing the binding affinity. We then collected the ACE2 gene sequences from 57 non-human primates. Among the six apes and 20 Old World monkeys (OWMs) studied we found no new variants. In contrast, all 11 New World monkeys (NWMs) studied share four variants each causing a strong reduction in binding affinity, the Philippine tarsier also possesses three such variants, and 18 of the 19 prosimian species studied share one variant causing a strong reduction in binding affinity. Moreover, one OWM and three prosimian variants increased binding affinity by > 50%. Based on these findings we proposed that the common ancestor of primates was strongly resistant to and that of NWMs was completely resistant to SARS-CoV-2 and so is the Philippine tarsier, whereas apes and OWMs, like most humans, are susceptible. This study increases our understanding of the differences in susceptibility to SARS-CoV-2 infection among primates.

Hepatitis C virus (HCV) NS3 protein possesses protease and helicase activities and is considered an oncoprotein in virus-derived hepatocellular carcinoma. The NS3-associated oncogenesis has been studied but not fully understood. In this study, we have identified novel interactions of the NS3 protein with DNA repair factors, Werner syndrome protein (WRN) and Ku70, in both an HCV subgenomic replicon system and Huh7 cells expressing NS3. HCV NS3 protein inhibits WRN-mediated DNA repair and reduces the repair efficiency of nonhomologous end joining. It interferes with Ku70 recruitment to the double-strand break sites and alters the nuclear distribution of WRN-Ku repair complex. In addition, WRN is a substrate of the NS3/4A protease; the level of WRN protein is regulated by both the proteasome degradation pathway and HCV NS3/4A protease activity. The dual role of HCV NS3 and NS3/4A proteins in regulating the function and expression level of the WRN protein intensifies the effect of impairment on DNA repair. This may lead to an accumulation of DNA mutations and genome instability and, eventually, tumor development. IMPORTANCE HCV infection is a worldwide problem of public health and a major contributor to hepatocellular carcinoma. The single-stranded RNA virus with RNA-dependent RNA polymerase experiences a high error rate and develops strategies to escape the immune system and hepatocarcinogenesis. Studies have revealed the involvement of HCV proteins in the impairment of DNA repair. The present study aimed to further elucidate mechanisms by which the viral NS3 protein impairs the repair of DNA damage. Our results clearly indicate that HCV NS3/4A protease targets WRN for degradation, and, at the same time, diminishes the repair efficiency of nonhomologous end joining by interfering with the recruitment of Ku protein to the DNA double-strand break sites. The study describes a novel mechanism by which the NS3 protein influences DNA repair and provides new insight into the molecular mechanism of HCV pathogenesis.

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