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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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World is witnessing one of the worst pandemics of this century caused by SARS-CoV-2 virus which has affected millions of individuals. Despite rapid efforts to develop vaccines and drugs for COVID-19, the disease is still not under control. Chloroquine (CQ) and Hydroxychloroquine (HCQ) are two very promising inhibitors which have shown positive effect in combating the disease in preliminary experimental studies, but their use was reduced due to severe side-effects. Here, we performed a theoretical investigation of the same by studying the binding of the molecules with SARS-COV-2 Spike protein, the complex formed by Spike and ACE2 human receptor and a human serine protease TMPRSS2 which aids in cleavage of the Spike protein to initiate the viral activation in the body. Both the molecules had shown very good docking energies in the range of -6kcal/mol. Subsequently, we did a high throughput screening for other potential quinoline candidates which could be used as inhibitors. From the large pool of ligand candidates, we shortlisted the top three ligands (binding energy -8kcal/mol). We tested the stability of the docked complexes by running Molecular Dynamics (MD) simulations where we observed the stability of the quinoline analogues with the Spike-ACE2 and TMPRSS2 nevertheless the quinolines were not stable with the Spike protein alone. Thus, although the inhibitors bond very well with the protein molecules their intrinsic binding affinity depends on the protein dynamics. Moreover, the quinolines were stable when bound to electronegative pockets of Spike-ACE2 or TMPRSS2 but not with Viral Spike protein. We also observed that a Fluoride based compound: 3-[3-(Trifluoromethyl)phenyl]quinoline helps the inhibitor to bind with both Spike-ACE2 and TMPRSS2 with equal probability. The molecular details presented in this study would be very useful for developing quinoline based drugs for COVID-19 treatment.
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The electrolyte additive 2-(pentafluorophenyl)-tetrafluoro-1,3,2-benzodioxaborole (PFPTFBB, 1) was found to have a reversible redox potential at 4.43 V vs. Li{sup +}/Li. This compound can function as an overcharge protection additive as well as anion receptor for lithium-ion batteries. It has drawn a great deal of interest from industry, but its use in relatively large quantities is limited by the production challenges of tetrafluorocatechol (TFC, 3), which is the key starting chemical for the synthesis of PFPTFBB. As part of a continuous effort in our research toward improving the safety of lithium-ion batteries, we have performed the synthesis of TFC and optimized its synthesis process. The X-ray single-crystal structures of TFC and the intermediate product 5,6,7,8-tetrafluoro-1,4-benzodioxane (4) during the process of PFPTFBB synthesis are reported for the first time. Also presented is the lithium ion cell performance of PFPTFBB as redox shuttle in various electrolyte systems.
Here, the energy density and cost of battery systems could be improved by moving to alternative battery chemistries such as Ca-ion. However, in order to switch chemistries many problems need to be solved including the identification of cathode materials with high energy density, and electrolytes that can plate and strip calcium metal. Herein, the feasibility and cycling performance of Ca 2+ intercalation into a desodiated layered Na 2 FePO 4 F host is described. This is the first demonstration of Ca 2+ intercalation into a polyanionic framework, which implies that other polyanionic framework materials may be active for Ca 2+ intercalation. Although substantial effort is still needed to identify a high energy density cathode material, this study and others demonstrate the feasibility of Ca 2+ intercalation into multiple materials making it more probable that such a cathode material can be found.
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The synthesis of a series of lanthanide trifluoroacetic acid (H-TFA) derivatives which contain only the TFA and its conjugate acid has been developed. From the reaction of Ln(N(SiMe 3 ) 2 ) 3 with an excess amount of H-TFA, the products were identified as: [Ln(μ-TFA) 3 (H-TFA) 2 ]n (Ln = Y, Ce, Sm, Eu, Gd, Tb, Dy), [Ln(μ-TFA) 3 (μ-H-TFA)] n ·solv (Ln·solv = Pr·2 H-TFA, H 3 O + , Ho·2py, Er·py, Yb·py, H-TFA), 3[H][(TFA)La(μ-TFA) 3 La(TFA)(μ-TFA) 2 (μ c -TFA) 2 ] n ½(H 2 O) ½(H 2 O, H-TFA) (La·½(H 2 O) ½(H 2 O, H-TFA)), [(k 2 -TFA)Nd(μ-TFA) 3 ] n ·H-py + (Nd·H-py + ), [(py) 2 Tm(μ-TFA) 3 ] n (Tm), or [Lu(μ-TFA) 4 Lu(μ-TFA) 3 ·H 3 O + ] n (Lu·H 3 O + ). Here, the majority of samples formed long chain polymers with 3 or 4 μ-TFA ligands. Tm was isolated with py coordinated to the metal, whereas Ho, Er, and Yb were isolated with py located within the lattice. Select samples from this set of compounds were used to generate nanomaterials under solvothermal (SOLVO) conditions using pyridine (py) or octylamine at 185 °C for 24 h. The SOLVO products were isolated as: (i) from py: La – fluocerite (LaF 3 , PDF 98-000-0214, R = 9.64%, 35(0) nm), Tb – terbium fluoride (TbF 3 , PDF 00-037-1487, R = 4.76%, 21(2) nm), Lu lutetium oxy fluoride (LuOF, PDF 00-052-0779, R = 8.24%, 8(2) nm); (ii) from octylamine: La – fluocerite/lanthanum oxide carbonate (LaF 3 , PDF 98-000-0214, R = 7.47%, 5(0) nm; La 2 O 2 (CO 3 ), PDF 01-070-5539, R = 12.32%, 12(0) nm), Tb – terbium oxy fluoride (TbOF, PDF 00-008-0230, R = 7.01%, 5(0) nm); Lu – lutetium oxide (Lu 2 O 3 , PDF 00-012-0728, R = 6.52%, 6(1) nm).
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Abstract not provided