West Nile virus noncoding subgenomic RNA contributes to viral evasion of the type I interferon-mediated antiviral response

We previously showed that a noncoding subgenomic flavivirus RNA (sfRNA) is required for viral pathogenicity, as a mutant West Nile virus (WNV) deficient in sfRNA production replicated poorly in wild-type mice. To investigate the possible immunomodulatory or immune evasive functions of sfRNA, we utilized mice and cells deficient in elements of the type I interferon (IFN) response. Replication of the sfRNA mutant WNV was rescued in mice and cells lacking interferon regulatory factor 3 (IRF-3) and IRF-7 and in mice lacking the type I alpha/beta interferon receptor (IFNAR), suggesting a contribution for sfRNA in overcoming the antiviral response mediated by type I IFN. This was confirmed by demonstrating rescue of mutant virus replication in the presence of IFNAR neutralizing antibodies, greater sensitivity of mutant virus replication to IFN-α pretreatment, partial rescue of its infectivity in cells deficient in RNase L, and direct effects of transfected sfRNA on rescuing replication of unrelated Semliki Forest virus in cells pretreated with IFN-α. The results define a novel function of sfRNA in flavivirus pathogenesis via its contribution to viral evasion of the type I interferon response.     

The effect of a protein on the radiolysis of DNA studied by gel filtration

Double stranded DNA from calf thymus was irradiated in the presence of bovine serum albumin with a ratio of 1:10 in weight under aerobic and anaerobic conditions. The irradiated biomolecules were separated by gel filtration on Sepharose Cl-2B with and without sodium dodecylsulphate. By scavenging OH-radicals the protein protects DNA, but in contrast to radiolysis of DNA in phosphate buffer, in the presence of serum albumin oxygen enhances the degradation of DNA. Radiolysis under N2 leads to crosslinking of serum albumin to DNA with higher yields at pH 5 than at pH 7. Oxygen largely prevents crosslinking.     

The effect of a protein on the radiolysis of DNA studied by HPLC and pulse radiolysis

Double-stranded DNA from calf thymus was irradiated in the presence of bovine serum albumin (BSA) with a ratio of 1:10 in weight, at pH7 and pH5, under aerobic and under anaerobic conditions. The irradiated biomolecules were separated by high-performance liquid-gel permeation chromatography. At pH 7, in the presence of the protein, degradation of DNA was enhanced by oxygen, while under anaerobic conditions formation of protein-DNA crosslinks was observed. At pH5, crosslinking of BSA to DNA occurred under anaerobic as well as under aerobic conditions, while fragmentation of DNA could not be detected with this method with doses up to 1600 Gy. Under nitrogen, the degradation of BSA was not altered by the addition of DNA, but in the presence of oxygen less BSA was lost for a given dose when DNA was present.     

Potentialities of fluorescent carbon nanomaterials as sensor for food analysis

Food safety and quality are among the most significant and prevalent research areas worldwide. The fabrication of appropriate technical procedures or devices for the recognition of hazardous features in foods is essential to safeguard food materials. In the recent era, developing high-performance sensors based on carbon nanomaterial for food safety investigation has made noteworthy progress. Hence this review briefly highlights the different detection approaches (colorimetric sensor, fluorescence sensor, surface-enhanced Raman scattering, surface plasmon resonance, chemiluminescence, and electroluminescence), functional carbon nanomaterials with various dimensions (quantum dots, graphene quantum dots) and detection mechanisms. Further, this review emphasizes the assimilation of carbon nanomaterials with optical sensors to identify multiple contaminants in food products. The insights of carbon-based nanomaterials optical sensors for pesticides and insecticides, toxic metals, antibiotics, microorganisms, and mycotoxins detection are described in detail. Finally, the opportunities and future perspectives of nanomaterials-based optical analytical approaches for detecting various food contaminants are discussed.