Farwa Mukhtar

and 7 more

The structural proteins, spike (S), nucleocapsid (N), membrane (M), and envelope (E), of severe acute respiratory syndrome (SARS-CoV-2) play a critical role from attachment to replication and virulency. Recently a bulk of genomes have been sequenced from different geographical regions with significant number of variations. Therefore, the current study was aimed to find variations in the structural proteins. This is the first comprehensive study in which we screened 2,95,000 complete genomes in global initiative on sharing all influenza data (GISAID), submitted from December 2019 to December 2020. We detected 4725 non-synonymous mutations in S, 627 in M, 259 in E, and 1631 mutations in N protein, among which the most frequently occurring mutations in S protein are D614G (n=2,66,513), A222V (n=59,697), L18F (n=28,015) and that of M protein are; T175M (n=1286), D3G (n=968), L17I (n=621), A2V (n=463), and A2S (n=460). The most commonly circulating variants in E includes, S68F (n=419), P71S (n=264), and L73F (n=218). Similarly, the N protein also harbored the most common variants which include; R203K (n=82,570), G204R (n=81,858), and A220V (n=39,729). The frequency of N501Y (n=4362) in S is determining a tight interaction of CoV-2 RBD with ACE2. These wide range of mutations in structural proteins may not only affect the therapeutic efforts but also the vaccines efficacy and diagnostics specificity. We suggest that geographically strain specific variations should be investigated for effective drugs, vaccine, and the antibodies combinations. Alternatively, immune boosting compounds might be very useful for successful eradication of CoV-2 infections.

Yongkai Wei

and 4 more

Ternary metal hydrides play an essential role in the search for conventional high-temperature superconductors because they can be synthesized under mild condition and recovered at ambient pressure. It has been widely accepted that the electronic structure, metallization pressure and superconducting behavior of binary hydrides can be adjusted effectively by doping, replacing or introducing a new element. In this work, yttrium hydrides were chosen as parent hydrides while scandium was considered as the doped element to perform systematical crystal structure searches on the Sc-Y-H system under pressure. A new ternary hydride ScYH6 was found according to PSO calculations, and it presents high symmetric character below 150 GPa with a Pm-3 structure (cP8), then a P4/mmm phase (tP8) becomes favorable from 150 GPa. Importantly, cP8-ScYH6 is dynamically stable under pressure as low as 0.01 GPa with a Tc of 32.110 K for Coulomb pseudopotential μ∗=0.13, indicating ternary hydrides are promising candidates in the search for superconductors which can be synthesized under mild conditions in hydrogen-rich materials. The analysis through “triangle straight-line method” (TSLM) compared with enthalpy difference calculations showed the most reasonable synthesis pathway of ScYH6 is in the whole studied pressure range. The Tc of ScYH6 takes a linear relationship with pressure up to 52.907 K under 200 GPa. The lattice dynamical calculations demonstrate the H atoms in both cP8 and tP8 structures make crucial contributions to the superconducting behavior of ScYH6. These findings can further reveal the influence of doping, replacing and introducing new element on superconducting behavior of binary hydrides.