Entangling of Peptide Nanofibers Reduces the Invasiveness of SARS-CoV-2

The viral spike (S) protein on the surface of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to angiotensin-converting enzyme 2 (ACE2) receptors on the host cells, facilitating its entry and infection. Here, functionalized nanofibers targeting the S protein with peptide sequences of IRQFFKK, WVHFYHK and NSGGSVH, which are screened from a high-throughput one-bead one-compound screening strategy, are designed and prepared. The flexible nanofibers support multiple binding sites and efficiently entangle SARS-CoV-2, forming a nanofibrous network that blocks the interaction between the S protein of SARS-CoV-2 and the ACE2 on host cells, and efficiently reduce the invasiveness of SARS-CoV-2. In summary, nanofibers entangling represents a smart nanomedicine for the prevention of SARS-CoV-2.

Molecular high-order harmonic spectra and its application to the generation of the isolated attosecond pulse

Molecular high-order harmonic generation (HHG) spectra from H₂⁺ and its application to the generation of the isolated attosecond pulses (IAPs) have been numerically investigated. Results show that (i) the 7th harmonic order is enhanced with the nuclei around the equilibrium internuclear, and as the internuclear distance increased, this enhanced harmonic produces a red-shift (even disappearance). Theoretical analyses show that the electronic transition between the ground and the 1st excited states is responsible for the red-shift enhanced harmonic. (ii) The harmonic spectra exhibit several maxima and minima, and a red-shift of these points is predicted as the internuclear distance increased. (iii) By properly choosing the internuclear distance, the harmonic yield is enhanced, and there is only the single quantum path contributing to the harmonic spectra. (iv) Further, by properly adding the half-cycle pulse as well as the spatial inhomogeneous effect, a 375 eV supercontinuum with a pulse enhancement of 3.9 dB and some attosecond X-ray pulses shorter than 60as can be produced.

Theoretical investigation of the asymmetric molecular harmonic emission and the attosecond pulse generation

The harmonic emission of the asymmetric charged molecule HeH(2+) ion is theoretically investigated by solving the one-dimensional-time-dependent Schrödinger equation. Results show that the laser-induced electron transfer process between the vibrational state and the ground electronic state is responsible for the resonant peak on the harmonic spectrum, and that the two ionization pathways are behind the two identified cutoff energies. In addition, by optimizing the asymmetric harmonic emission, the generations of the ultrashort attosecond pulses are also discussed.

Intensity enhancement in the molecular ionization and dissociation dynamics in the presence of noise

The ionization and the dissociation of the diatomic molecular ion H(2)(+) have been investigated within a scheme where a noise field is added to an intense infrared laser field. The results show that both the ionization and the dissociation probabilities are enhanced with the introduction of the additional noise (the Gaussian white noise or the color noise) field. Further, by tuning the noise intensity and the delay time between the laser and the noise, a stochastic resonancelike curve is observed for the ionization or the dissociation dynamics, showing the existence of an optimal noise intensity and delay time for the given laser field.

[Monocytes are more susceptible in vitro in rhesus macaques of Chinese origin to recombinant serotype 5 adenovirus with higher preexisting vector specific neutralizing antibody titer]

Human adenovirus serotype 5 (HAd5) infect dendritic cells with low efficiency which restricts the use of HAd5 as an antigen carrying vector in such cells. Aiming to find a novel strategy to detour the traditional method for more convenient clinical use, peripheral blood mononuclear cells isolated from Chinese rhesus macaques were chosen as the target cells for HAd5. In vitro infection protocol was optimized which indicated centrifugation at 1000g could ease the entry of adenovirus. By this protocol, CD14 positive monocytes were infected at high efficiencies (> 80%), and about 10% of natural killer cells were infected; while T and B lymphocytes were rarely infected. Interestingly and importantly, it was the first time to report that in our in vitro study monocytes were more susceptible to HAd5-EGFP in macaques with higher preexisting vector specific neutralizing antibody titers. This phenomenon indicates an expansion of application of adenovirus based vectors for vaccine development and clinical use, especially for the population with preexisting neutralizing antibodies.