Inactivation Activities of Ozonated Water,Slightly Acidic Electrolyzed Water and Ethanol against SARS-CoV-2

This study aimed to compare the SARS-CoV-2-inactivation activity and virucidal mechanisms of ozonated water (OW) with those of slightly acidic electrolyzed water (SAEW) and 70% ethanol (EtOH). SARS-CoV-2-inactivation activity was evaluated in a virus solution containing 1%, 20% or 40% fetal bovine serum (FBS) with OW, SAEW or EtOH at a virus-to-test solution ratio of 1:9, 1:19 or 1:99 for a reaction time of 20 s. EtOH showed the strongest virucidal activity, followed by SAEW and OW. Even though EtOH potently inactivated the virus despite the 40% FBS concentration, virus inactivation by OW and SAEW decreased in proportion to the increase in FBS concentration. Nevertheless, OW and SAEW showed potent virucidal activity with 40% FBS at a virus-to-test solution ratio of 1:99. Real-time PCR targeting the viral genome revealed that cycle threshold values in the OW and SAEW groups were significantly higher than those in the control group, suggesting that OW and SAEW disrupted the viral genome. Western blotting analysis targeting the recombinant viral spike protein S1 subunit showed a change in the specific band into a ladder upon treatment with OW and SAEW. OW and SAEW may cause conformational changes in the S1 subunit of the SARS-CoV-2 spike protein.     

Thermal properties of a molecule in a constrained state

The thermal properties of a dye molecule (guest) inside the cavity of a host amylose helix were studied by TGA, DSC, and Thermal Desorption MS. The results show that the degradation temperature of dye shifts to a higher temperature by approximately 20°C.     

The influence of humic acid on the pH-dependent sorption of americium(III) onto kaolinite

This work investigates the sorption of americium [Am(III)] onto kaolinite and the influence of humic acid (HA) as a function of pH (3–11). It has been studied by batch experiments (V/m = 250:1 mL/g, C _Am(III) = 1 × 10⁻⁵ mol/L, C _HA = 50 mg/L). Results showed that the Am(III) sorption onto the kaolinite in the absence of HA was typical, showing increases with pH and a distinct adsorption edge at pH 3–5. However in the presence of HA, Am sorption to kaolinite was significantly affected. HA was shown to enhance Am sorption in the acidic pH range (pH 3–4) due to the formation of additional binding sites for Am coming from HA adsorbed onto kaolinite surface, but reduce Am sorption in the intermediate and high pH above 6 due to the formation of aqueous Am-humate complexes. The results on the ternary interaction of kaolinite–Am–HA are compared with those on the binary system of kaolinite–HA and kaolinite–Am and adsorption mechanism with pH are discussed. Effect of different molecular weight of HA, with three HA fractions separated by ultrafiltration techniques, on the Am sorption to kaolinite were also studied. The results showed that the enhancement of the sorption of Am onto kaolinite at the acidic pH conditions (pH 3–4) was higher with HA fractions of higher molecular weight. Also, the Am sorption over a pH range from 6 to 10 decreased with decreasing molecular weight of HA.     

Total synthesis of 10-deoxymethynolide and narbonolide

A flexible and convenient approach was developed for the synthesis of 10-deoxymethynolide (1) and narbonolide (2), which are aglycones of the methymycin and the pikromycin families of macrolide antibiotics. These lactones are produced by pikromycin polyketide synthase from Streptomyces venezuelae. Polyketide lactones, 10-deoxymethynolide and narbonolide, which contain 12- and 14-membered rings, respectively, were synthesized efficiently. These target lactones were retrosynthetically divided into three parts and assembled by using an asymmetric aldol reaction, the Yamaguchi esterification, and ring-closing metathesis. The ring-closing metathesis reaction catalyzed by the second-generation Grubbs catalyst is particularly efficient in preparing these macrocyclic polyketide lactones.     

Synthesis and catalytic properties of barium hexaaluminates incorporated with chromium and lanthanum

Summary Barium hexaaluminates incorporated with chromium and lanthanum (Ba_1-xLa_xCrAl₁₁O_19-a) were synthesized from aqueous metal nitrates and sulfates through the precipitation, and then followed by crystallization at 1300^oC for 2 h. They had the ability to maintain heat resistance and high conversion of CH₄in methane combustion at elevated temperature.     

Vesicle formed by amphiphilc cucurbit[6]uril: versatile, noncovalent modification of the vesicle surface, and multivalent binding of sugar-decorated vesicles to lectin

We report a novel vesicle formed by an amphiphilic CB[6] derivative, the surface of which can be easily modified via host-guest interactions by taking advantage of molecular cavities, readily accessible at the vesicle surface, and their strong affinity toward polyamines. Amphiphilic CB[6] derivative 1 synthesized by reaction between (allyloxy)12CB[6] and 2-[2-(2-methoxyethoxy)ethoxy]ethanethiol affords a vesicle that has been characterized by TEM, light scattering, and fluorescent dye entrapment experiments. Treatment of vesicle 1 with FITC (fluorescein isothiocyanate)-spermine conjugate ligand 2, in which spermine serves as a binding motif to CB[6] and FITC as a fluorescent tag, produced a surface-modified vesicle, which can be easily visualized by a confocal microscope. This result provides us with a new noncovalent, modular approach to the modification of vesicle surfaces. By treating the vesicle derived from the amphiphilic CB[6] with a tag-attached polyamine, we can easily decorate the surface of the vesicle with the tag. Sugar-decorated vesicles were prepared by this noncovalent method, and their interactions with concanavalin A (ConA) were studied. The binding constant of the vesicle decorated with mannose-spermidine conjugate 3 to ConA was measured to be approximately 3 x 104 M-1, which is almost 3 orders of magnitude higher than that of free ligand 3 to ConA (K = approximately 50 M-1). On the other hand, the binding constant of the vesicle coated with galactose-spermidine conjugate 4 to ConA was too small to be measured. These results illustrate the specific and multivalent interactions between the mannose-decorated vesicle and ConA. The ability for facile surface modification suggests many practical applications, including its use in targeted drug delivery and immunization.     

Sensitive fluorescence assay of anthrax protective antigen with two new DNA aptamers and their binding properties

A homogeneous assay of the protective antigen in anthrax toxin is reported using two new PA-specific aptamers for selective and sensitive detection, based on reduction in the fluorescence emission according to the formation of the aptamer-PA ternary complex. PA at 1 nM was readily detected using OliGreen as a fluorophore in HEPES buffer. We also demonstrated that the PA detection could be performed in blood serum. The binding interaction between the aptamer and PA was strong enough to dehybridize double-stranded DNA paired completely with 12 bases at room temperature. Moreover, this fluorescence study revealed that the binding sites of the two aptamers were located differently on the PA protein. We believe our approach may lay the groundwork for the real-time detection of PA.     

Synthetic studies on soft coral norcembranolides: total synthesis of (+)-10-epigyrosanolide E

Total synthesis of (+)-10-epigyrosanolide E was accomplished employing SmI₂-mediated 5-exo cyclization of an aldehydo β-alkoxyvinyl sulfoxide and ring-closing metathesis reaction.     

Palladium-nickel alloys loaded on tungsten carbide as platinum-free anode electrocatalysts for polymer electrolyte membrane fuel cells

The strong interaction between PdNi alloys and WC makes PdNi/WC a novel Pt-free electrocatalyst for the anode hydrogen oxidation reaction of polymer electrolyte membrane fuel cells with activity and stability comparable to those of the conventional Pt/C catalysts.     

Fermi level engineering of single-walled carbon nanotubes by AuCl3 doping

We investigated the modulation of optical properties of single-walled carbon nanotubes (SWCNTs) by AuCl 3 doping. The van Hove singularity transitions (E 11 (S), E 22 (S), E 11 (M)) in absorption spectroscopy disappeared gradually with an increasing doping concentration and a new peak appeared at a high doping concentration. The work function was downshifted up to 0.42 eV by a strong charge transfer from the SWCNTs to AuCl 3 by a high level of p-doping. We propose that this large work function shift forces the Fermi level of the SWCNTs to be located deep in the valence band, i.e., highly degenerate, creating empty van Hove singularity states, and hence the work function shift invokes a new asymmetric transition in the absorption spectroscopy from a deeper level to newly generated empty states.