Host innate recognition triggers key immune responses for viral elimination. The sensing mechanism of hepatitis B virus (HBV), a DNA virus, and the subsequent downstream signaling events remain to be fully clarified. Here we found that type III but not type I interferons are predominantly induced in human primary hepatocytes in response to HBV infection, through retinoic acid-inducible gene-I (RIG-I)-mediated sensing of the 5'-ε region of HBV pregenomic RNA. In addition, RIG-I could also counteract the interaction of HBV polymerase (P protein) with the 5'-ε region in an RNA-binding dependent manner, which consistently suppressed viral replication. Liposome-mediated delivery and vector-based expression of this ε region-derived RNA in liver abolished the HBV replication in human hepatocyte-chimeric mice. These findings identify an innate-recognition mechanism by which RIG-I dually functions as an HBV sensor activating innate signaling and to counteract viral polymerase in human hepatocytes.
Molecular dynamics (MD) simulations were performed to investigate the adsorption behavior and dynamics of Arg-Gly-Asp (RGD) tripeptide onto the rutile TiO(2) (110) perfect and grooved surfaces in aqueous solution. The simulation results suggest that, driven by the electrostatic attractions between charged groups of the tripeptide and opposite-type charges of the surface atoms, RGD substitutes the adsorbed water molecules and binds to TiO(2) surface strongly through direct interactions of carboxyl oxygen (O(coo(-))) atoms with nearby titanium atoms in the interface, in agreement with some experimental observations and theoretical data. Once bonded to both perfect and grooved surfaces, RGD tripeptides show a reasonable propensity to remain there with the carboxyl groups providing anchors to the substrate surface, while the amide groups (NH(3)(+) and NH(2)) with larger separations from the attached portions, undergo relatively remarkable fluctuations during the whole simulation time. The trajectories for atom-surface distances, backbone dihedral angles and root-mean-squared deviations from the initial structure have revealed less mobility and more stable adsorption of RGD onto grooved surface than onto perfect surface, which is confirmed again by greater values of adsorption energy for available grooved surfaces.
A significant impediment to the deployment of anti-counterfeiting technologies is the reliance on specialized hardware. Here, anti-counterfeiting labels are developed that are both excited and detected using a smartphone. The persistent luminescence pattern and color changes on the timescale of hundreds of milliseconds to seconds. The labels can be authenticated by comparing still images from the red and green channels of video acquired at known times after flashlight excitation against expected reference patterns. The labels are based on a green-emitting SrAl2O4: Eu2+,Dy3+ (SAED), and red-emitting CaS:Eu2+ phosphors whose lifetimes are varied: (i) for SAED from 0.5 to 11.7 s by annealing the commercial material in air; and (ii) CaS:Eu2+ from 0.1 to 0.6 s by varying the dopant concentration. Examples of anti-counterfeiting labels exhibiting changing emission patterns and colors on a seven-segment display, barcode, and emoji are demonstrated. These results demonstrate that phosphors with visible absorption and tunable persistent luminescence lifetimes on the order of hundreds of milliseconds to seconds are attractive for anti-counterfeiting applications as they allow authentication to be performed using only a smartphone. Further development should allow richer color shifts and enhancement of security by embedding further covert anti-counterfeiting features.
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