SARS-CoV-2 Omicron-B.1.1.529 leads to widespread escape from neutralizing antibody responses

On 24th November 2021, the sequence of a new SARS-CoV-2 viral isolate Omicron-B.1.1.529 was announced, containing far more mutations in Spike (S) than previously reported variants. Neutralization titers of Omicron by sera from vaccinees and convalescent subjects infected with early pandemic Alpha, Beta, Gamma, or Delta are substantially reduced, or the sera failed to neutralize. Titers against Omicron are boosted by third vaccine doses and are high in both vaccinated individuals and those infected by Delta. Mutations in Omicron knock out or substantially reduce neutralization by most of the large panel of potent monoclonal antibodies and antibodies under commercial development. Omicron S has structural changes from earlier viruses and uses mutations that confer tight binding to ACE2 to unleash evolution driven by immune escape. This leads to a large number of mutations in the ACE2 binding site and rebalances receptor affinity to that of earlier pandemic viruses

ROVIBRATIONAL STATE MIXING IN THE ALDEHYDE C-H STRETCH FUNDAMENTAL REGION OF ACETALDEHYDE

ABSTRACT We have studied rovibrational state mixing in acetaldehyde using infrared laser induced fluorescence. Molecules are isolated and cooled in supersonic molecular beams, and irradiated in the C???H stretch fundamental region with an infrared optical parametric oscillator. Spectral resolution is provided with either a circular variable filter machine or a cryogenic Michelson interferometer. We have found evidence of several strong Fermi resonances between the aldehyde C???H stretch and a few overtones and combinations of lower frequency modes. In addition, there is substantial random state mixing in this region as evidenced by the average experimental dilution factor of 0.2. The dependence of the dilution factor on the average J excited by the laser shows that the extent of state mixing scales linearly with J. We have observed from dispersed fluorescence spectra that random rotational coupling occurs between different Kp states. Our previous statistical coupling model has been applied to the interpretation of the data, and its applicability is discussed. For the model calculation, the methyl torsion is specially treated as a very anharmonic mode in the eumeration of the zeroth order bath states. The average coupling width derived from the model calculation is 0.35 cm???1. The relative energy content apportioned among vibrational modes in the molecule following excitation is measured and is successfully explained with the model

Intrinsic synergistic-topological mechanism versus synergistic-topological matrix in microtubule self-organization

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