Discovery of orally bioavailable SARS-CoV-2 papain-like protease inhibitor as a potential treatment for COVID-19.

The RNA-dependent RNA polymerase (RdRp), 3C-like protease (3CL), and papain-like protease (PL) are pivotal components in the viral life cycle of SARS-CoV-2, presenting as promising therapeutic targets. Currently, all FDA-approved antiviral drugs against SARS-CoV-2 are RdRp or 3CL inhibitors. However, the mutations causing drug resistance have been observed in RdRp and 3CL from SARS-CoV-2, which makes it necessary to develop antivirals with novel mechanisms.

Selective Synthesis of Non-Aromatic Five-Membered Sulfur Heterocycles from Alkynes by using a Proton Acid/N-Chlorophthalimide System.

A multicomponent strategy to achieve two different regioselectivities from alkynes, isothiocyanates and H O with a proton acid/N-chlorophthalimide (NCPI) system is described to selectively obtain non-aromatic five-membered sulfur heterocycles (1,3-oxathiol-2-imines/thiazol-2(3H)-one derivatives) through multiple bond formations. The process features readily available starting materials, mild reaction conditions, broad substrate scope, good functional-group tolerance, high regio- and chemo- selectivities, gram-scale synthesis and late-stage modifications. Mechanistic studies support the proposal that the transformation process includes a combination of H O and isothiocyanate, free-radical formation, carbonation and intramolecular cyclization to give the products.

Access to 2-Aroylthienothiazoles via C-H/N-O Bond Functionalization of Oximes.

A novel strategy for the synthesis of 2-aroylthienothiazoles via C-H/N-O bond functionalization of ketoximes is developed. This reaction features excellent step- and atom-economy, as well as broad substrate scope. Various common ketoximes, even vinyl ketoximes, were efficiently converted to 2-aroylthienothiazoles.

Direct access to bis-S-heterocycles via copper-catalyzed three component tandem cyclization using S as a sulfur source.

A novel strategy for constructing sulfur containing bis-S-heterocyclic compounds from oxime esters/vinyl azide, phenylacetylene/aldehydes and elemental sulfur (S8) has been developed. These transformations show good functional group tolerance. Various bis-S-heterocyclic products were efficiently synthesized from easily prepared or widely commercially available starting materials.

Laser tuned large position-dependent tunneling detection dominated by interface states in silicon based oxide-semiconductor structure.

A laser tuned tunneling detection is observed in SiO(50nm)/p-Si/SiO structure. In comparison of dark condition, the tunneling current get amplified considerably over 250 times when irradiated with a low intensity laser (5mW) directly on the oxide layers. This huge amplified tunneling is unusual and rarely seen.

High voltage endurance and switchable resistance effect observed in nanoscale copper groove structure.

A switchable lateral resistance effect with high reverse voltage has been observed in nanoscale copper groove structure. With the stimulation of electric pulse and local illumination of laser, the lateral resistance of the structure can be modulated in a non-volatile manner. We attribute this phenomenon to the different width of depletion region and the Schottky barrier change caused by the nanoscale charge trapping effect.

High-gain erbium silicate waveguide amplifier and a low-threshold, high-efficiency laser.

Erbium-doped materials have played an important role in the fabrication of light sources used in silicon photonics. Recent studies demonstrated that erbium silicate nanowire had a high net gain attributable to its high erbium concentration and excellent material quality. We establish a more accurate and comprehensive theoretical model of erbium silicate nanowire, analyze the modeled nanowire's properties, and optimize a high-gain erbium silicate waveguide amplifier and low-threshold, high-efficiency laser by considering upconversion, energy transfer, and amplified spontaneous emission.

High sensitive position-dependent photodetection observed in Cu-covered Si nanopyramids.

Silicon nanopyramids with the excellent ability of light absorption have been mostly reported in solar cells. Here, we report an obviously enhanced lateral photovoltaic effect (LPE) in copper-nanoparticle-covered random Si nanopyramids (Cu@Si-pyramid). Remarkable photoelectric responses are achieved in broadband from 405 to 780 nm.

Controllable assembly of the benzothiazole framework using a C[triple bond, length as m-dash]C triple bond as a one-carbon synthon.

A concise and efficient protocol to assemble diverse benzothiazole derivatives in high yields was provided via copper catalyzed tandem cyclization with o-haloanilines, elemental sulfur and terminal alkynes as raw materials. In this protocol, C atoms on the C[triple bond, length as m-dash]C triple bond were controllably involved in the construction of the benzothiazole framework and multiple carbon-heteroatom bonds through divergent routes.

Selective Construction of 2-Substituted Benzothiazoles from o-Iodoaniline Derivatives S and N-Tosylhydrazones.

Selective construction of 2-substituted benzothiazoles from o-iodoaniline derivatives S and N-tosylhydrazone via a copper-promoted [3 + 1 + 1]-type cyclization reaction has been realized. In the protocol, the carbon atom on N-tosylhydrazone could be regulated to construct benzothiazole by changing the reaction system. Furthermore, the transformation has achieved the construction of multiple carbon-heteroatom bonds.

Localized Surface Plasmon Induced Position-Sensitive Photodetection in Silicon-Nanowire-Modified Ag/Si.

Surface plasmon-based approaches are widely applied to improve the efficiency of photoelectric devices such as photosensors and photocells. In order to promote the light absorption and electron-hole pair generation in devices, metallodielectric nanostructures are used to boost the growth of surface plasmons. Here, silicon nanowires (SiNWs) are used to modify a metal-semiconductor structure; thus, Ag/SiNWs/Si is manufactured.

Size-dependent magnetic tuning of lateral photovoltaic effect in nonmagnetic Si-based Schottky junctions.

In this article, we report a magnetic tuning lateral photovoltaic effect (LPE) in a nonmagnetic Si-based Schottky junctions. In the magnetic field intensity range of 0 to 1.6 T, the variation amplitude of LPE sensitivity is as high as 94.

Nonvolatile and tunable switching of lateral photo-voltage triggered by laser and electric pulse in metal dusted metal-oxide-semiconductor structures.

Owing to the innate stabilization of built-in potential in p-n junction or metal-oxide-semiconductor structure, the sensitivity and linearity of most lateral photovoltaic effect (LPE) devices is always fixed after fabrication. Here we report a nonvolatile and tunable switching effect of lateral photo-voltage (LPV) in Cu dusted ultrathin metal-oxide-semiconductor structure. With the stimulation of electric pulse and local illumination, the sensitivity and linearity of LPV can be adjusted up and down in a nonvolatile manner.

Localized surface plasmon resonances dominated giant lateral photovoltaic effect observed in ZnO/Ag/Si nanostructure.

We report substantially enlarged lateral photovoltaic effect (LPE) in the ZnO/Ag/Si nanostructures. The maximum LPE sensitivity (55.05 mv/mm) obtained in this structure is about seven times larger than that observed in the control sample (7.