Theory for nanoscale curvature induced enhanced inactivation kinetics of SARS-CoV-2.

We develop a novel theory for the nanomorphology dependent outer sphere heterogeneous electron transfer (ET) rate constant () based on an energy level alignment approach. is modelled through the activation free energy, which is a product of the water monolayer covered metal work function (WF) and the fractional electronic charge exchanged at the transition state (attained through the alignment of the metal Fermi and HOMO/LUMO energy levels of the electroactive species). The theory shows that is an exponentially increasing and decreasing function of the mean curvature in concave and convex nanomorphologies, respectively, for electroactive species or proteins involving their HOMO energy. For the specific spike protein of SARS-CoV-2, we have estimated the half lifetime (t1/2) and degree of inactivation as a function of the metal WF, nanostructure mean curvature, spike protein HOMO energy, and the environmental temperature (T). By varying the metal from Ag to Au, t1/2 is reduced from 7 h to 4 min, respectively. The reduction in the copper nanoparticle size from 50 to 5 nm increases the degree of inactivation from 60 to 99.6% (with a reduction factor of 10 in t1/2). Similarly, the increase in T from 10 °C to 65 °C causes a 100 times lowering of the t1/2 and t99.9% of SARS-CoV-2 on Cu metal. The theory predicts that involving the HOMO energy level of a protein follows the surface nanostructure shape dependent order as follows: spherical nanoparticle > cylindrical nanorod > cylindrical nanopore > spherical nanocavity, while the opposite trend is observed in the case of the LUMO energy level participation. Finally, the theory shows agreement with the reported experimental data of the degree of inactivation of SARS-CoV-2 on Ag and Cu nanoparticles.

Global Forestry Perspective: COVID-19 Impact and Assessment.

Corona virus disease 2019 (COVID-19) caused by corona virus SARS-CoV-2 is believed to be originated in Wuhan province of China, which has spread all over the world. It has severely impacted the social, cultural, educational, research and development programmes throughout the globe. Since the inception of various lifeforms on planet earth, forests' plays an important role in the evolutionary history of organisms and fitness persuades the existence of modern-day species in different ecosystems. The visible effect of pandemic leads to the lockdown with positive implications on the earth biosphere as a whole; while on other hand, lockdown seized and reduced the urbanization and developmental projects, especially the research and development progress in the field of forestry and allied sciences. This viewpoint addresses key questions and point-out with detailed exploration of the problem - as how COVID-19 pandemic impacts forestry research all over the world? We also suggest possible solutions, and define the role and association of disciplines, such as bioinformatics, remote sensing and statistical modules along with previously explored and collected field data as a sustainable measure to resolve the problems of forestry sector of this mighty challenge.