Molecular-Level Control of the Intersheet Distance and Electronic Coupling between 2D Semiconducting and Metallic Nanosheets: Establishing Design Rules for High-Performance Hybrid Photocatalysts.

Hybridization with conductive nanospecies has attracted intense research interest as a general effective means to improve the photocatalytic functionalities of nanostructured materials. To establish universal design rules for high-performance hybrid photocatalysts, correlations between versatile roles of conductive species and interfacial interaction between hybridized species are systematically investigated through fine-control of intersheet distance between photocatalytically active TiO and metallic reduced graphene oxide (rGO)/RuO nanosheets. Molecular-level tailoring of intersheet distance and electronic coupling between 2D nanosheets can be successfully achieved by restacking of colloidal nanosheet mixture with variable-sized organic intercalants.

Selection and characterization of toxic spore-specific DNA aptamer using spore-SELEX.

As airborne spores of toxic species cause mild symptoms to invasive fungal infections, their indoor concentration should be controlled through real-time management. Aptamer-based biosensors could provide economical and simple solutions for point-of-care. In this study, we isolated aptamers binding to the spores of three representative toxic species (, , and ) for the first time, using cell-SELEX (systematic evolution of ligands through exponential enrichment).

On-Chip Chemiresistive Sensor Array for On-Road NO Monitoring with Quantification.

The adverse effects of air pollution on respiratory health make air quality monitoring with high spatial and temporal resolutions essential especially in cities. Despite considerable interest and efforts, the application of various types of sensors is considered immature owing to insufficient sensitivity and cross-interference under ambient conditions. Here, a fully integrated chemiresistive sensor array (CSA) with parts-per-trillion sensitivity is demonstrated with its application for on-road NO monitoring.

Effect of TiCT MXenes etched at elevated temperatures using concentrated acid on binder-free supercapacitors.

The effect of TiCT MXene etched at different temperatures (25 °C, 50 °C, and 80 °C) on the capacitance of supercapacitors without the use of conducting carbon-black or a binder was studied. The MXene etched using concentrated HCl acid (12 M)/LiF was used as an active electrode and Ni-foil as a current collector. It was observed that the elevated etching temperature facilitates the etching of the MAX phase and the exfoliation of MXene layers.

Novel Feature Selection and Voting Classifier Algorithms for COVID-19 Classification in CT Images.

Diagnosis is a critical preventive step in Coronavirus research which has similar manifestations with other types of pneumonia. CT scans and X-rays play an important role in that direction. However, processing chest CT images and using them to accurately diagnose COVID-19 is a computationally expensive task.

Polymorph exploration of bismuth stannate using first-principles phonon mode mapping.

Accurately modelling polymorphism in crystalline solids remains a key challenge in computational chemistry. In this work, we apply a theoretically-rigorous phonon mode-mapping approach to understand the polymorphism in the ternary metal oxide BiSnO. Starting from the high-temperature cubic pyrochlore aristotype, we systematically explore the structural potential-energy surface and recover the two known low-temperature phases alongside three new metastable phases, together with the transition pathways connecting them.

Improvement in the thermoelectric performance of highly reproducible n-type (Bi,Sb)Se alloys by Cl-doping.

(Bi,Sb)Se alloys are promising alternatives to commercial n-type Bi(Te,Se) ingots for low-mid temperature thermoelectric power generation due to their high thermoelectric conversion efficiency at elevated temperatures. Herein, we report the enhanced high-temperature thermoelectric performance of the polycrystalline Cl-doped Bi Sb Se ( = 0.8, 1.

Solution-processed graphene oxide electrode for supercapacitors fabricated using low temperature thermal reduction.

We present a low temperature and solution-based fabrication process for reduced graphene oxide (rGO) electrodes for electric double layer capacitors (EDLCs). Through the heat treatment at 180 °C between the spin coatings of graphene oxide (GO) solution, an electrode with loosely stacked GO sheets could be obtained, and the GO base coating was partially reduced. The thickness of the electrodes could be freely controlled as these electrodes were prepared without an additive as a spacer.

Universal Oriented van der Waals Epitaxy of 1D Cyanide Chains on Hexagonal 2D Crystals.

The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and CuAuCN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h-BN, WS, MoS, WSe, MoSe, and MoTe).

Structure-tunable supraparticle assemblies of hollow cupric oxide sheathed with nanographenes.

Self-assembled supraparticles (SPs), a secondary structure of clustered nanoparticles, have attracted considerable interest owing to their highly tunable structure, composition, and morphology from their primary nanoparticle constituents. In this study, hierarchically assembled hollow CuO SPs were prepared using a cationic polyelectrolyte poly(diallyl dimethylammonium chloride) (PDDA) during the formation of CuO nanoparticles. The concentration-dependent structural transformation of PDDA from linear chains to assembled droplets plays a crucial role in forming a hollow colloidal template, affording the self-assembly of CuO nanoparticles as a secondary surfactant.

Lower Mg and S contents in solar salt used in kimchi enhances the taste and anticancer effects on HT-29 colon carcinoma cells.

The anticancer effects of kimchi prepared with different kinds of solar salts were evaluated in an cellular system using HT-29 human colon carcinoma cells. Four kinds of kimchi samples were prepared, using different solar salts: conventionally manufactured solar salt (CS), filtered sea water solar salt (FS), dehydrated solar salt by centrifuging (DS), and washed-dehydrated solar salt (WDS). Prepared kimchi samples were presented as CSK, FSK, DSK, and WDSK, respectively.

evaluation of the anti-obesity effects of combinations of pigment derivatives.

The prevention and treatment of obesity using naturally derived compounds is desirable in terms of marketing and safety in the nutraceutical and functional food markets. One of the noticeable effects of pigment derivatives is the inhibition/deactivation of lipid metabolism. Our earlier studies reported that threonine (Thr), tryptophan (Trp), and 2-(-tolyl)-ethylamine (TEA) derivatives of pigment showed cholesterol-lowering, lipase-inhibitory, and adipogenic differentiation-inhibitory activities, respectively.

High-Resolution 3D Printing of Freeform, Transparent Displays in Ambient Air.

Direct 3D printing technologies to produce 3D optoelectronic architectures have been explored extensively over the last several years. Although commercially available 3D printing techniques are useful for many applications, their limits in printable materials, printing resolutions, or processing temperatures are significant challenges for structural optoelectronics in achieving fully 3D-printed devices on 3D mechanical frames. Herein, the production of active optoelectronic devices with various form factors using a hybrid 3D printing process in ambient air is reported.

Heterostructure Engineering of a Reverse Water Gas Shift Photocatalyst.

To achieve substantial reductions in CO emissions, catalysts for the photoreduction of CO into value-added chemicals and fuels will most likely be at the heart of key renewable-energy technologies. Despite tremendous efforts, developing highly active and selective CO reduction photocatalysts remains a great challenge. Herein, a metal oxide heterostructure engineering strategy that enables the gas-phase, photocatalytic, heterogeneous hydrogenation of CO to CO with high performance metrics (i.

Optimization of the electron transport in quantum dot light-emitting diodes by codoping ZnO with gallium (Ga) and magnesium (Mg).

In our study, to optimize the electron-hole balance through controlling the electron transport layer (ETL) in the QD-LEDs, four materials (ZnO, ZnGaO, ZnMgO, and ZnGaMgO NPs) were synthesized and applied to the QD-LEDs as ETLs. By doping ZnO NPs with Ga, the electrons easily inject due to the increased Fermi level of ZnO NPs, and as Mg is further doped, the valence band maximum (VBM) of ZnO NPs deepens and blocks the holes more efficiently. Also, at the interface of QD/ETLs, Mg reduces non-radiative recombination by reducing oxygen vacancy defects on the surface of ZnO NPs.

Effect of counter-ions on the properties and performance of non-conjugated polyelectrolyte interlayers in solar cell and transistor devices.

We have investigated a series of non-conjugated polyelectrolytes (NPEs) which are based on a polyethylenimine (PEI) backbone with various counterions, such as Br I and BIm , as interfacial layers at the electrodes of solar cells and transistor devices to improve the power conversion efficiency (PCE) and device performance. This new series of NPEs with different counterions are capable of forming electric dipoles at NPE/metal electrode interfaces; as a consequence tuning of the energy levels, and work function (WF) of the electrodes is possible. Using this approach, the PCE of organic solar cells could be improved from 1.

High-energy proton irradiation damage on two-dimensional hexagonal boron nitride.

The dielectric layer, which is an essential building block in electronic device circuitry, is subject to intrinsic or induced defects that limit its performance. Nano-layers of hexagonal boron nitride (h-BN) represent a promising dielectric layer in nano-electronics owing to its excellent electronic and thermal properties. In order to further analyze this technology, two-dimensional (2D) h-BN dielectric layers were exposed to high-energy proton irradiation at various proton energies and doses to intentionally introduce defective sites.

Surface functionalization of silica using catalytic hydroesterification modified polybutadienes.

A new method for covalent immobilization of catalytic hydroesterification modified polybutadiene on a silica surface is described. Compared to conventional immobilization procedures, the new protocol enables control of the functional group composition on the modified silica surface.

Preparation of glycoside polymer micelles with antioxidant polyphenolic cores using alkylated poly(arbutin)s.

This paper describes the synthesis of long-chain-alkylated poly(arbutin)s (poly(Arb)- , where = alkyl-chain length and = degree of substitution (DS)) and their aqueous micelle formation. DS was controlled by tailoring the alkyl reagent/main-chain phenol substituent feed ratio. The critical micelle concentrations (CMCs) of poly(Arb)- were determined as 1.

Intense-pulsed-UV-converted perhydropolysilazane gate dielectrics for organic field-effect transistors and logic gates.

We fabricated a high-quality perhydropolysilazane (PHPS)-derived SiO film by intense pulsed UV irradiation and applied it as a gate dielectric layer in high-performance organic field-effect transistors (OFETs) and complementary inverters. The conversion process of PHPS to SiO was optimized by varying the number of intense pulses and applied voltage. The chemical structure and gate dielectric properties of the PHPS-derived SiO films were systematically investigated Fourier transform infrared spectroscopy and leakage current measurements, respectively.

Structural heterogeneity in polymeric nitric oxide donor nanoblended coatings for controlled release behaviors.

Nitric oxide (NO) gas delivery has attracted extensive interest due to its endogenous therapeutic functions and potential biomedical applications for the treatment of various diseases. The important thing about NO delivery is the emission control due to the fast diffusion rate of gas molecules. To develop NO delivery platforms using macromolecules and to comprehend the chemical NO donor generation and release mechanisms, we studied branched polyethyleneimine/alginate (BPEI/ALG) nanoblended coatings fabricated by giving structural heterogeneity to the structure through a self-assembly process for the controlled release of gas molecules.

Label-free and real-time monitoring of human mesenchymal stem cell differentiation in 2D and 3D cell culture systems using impedance cell sensors.

Three dimensional (3D) stem cell culture has recently received considerable attention because it may enable the development of 3D tissue models. In particular, label-free and real-time monitoring of stem cell differentiation is of importance for tissue engineering applications; however, only a few non-invasive monitoring methods are available, especially for 3D cell culture. Here, we describe impedance cell sensors that allowed the monitoring of cellular behaviors in 2D and 3D cell cultures in real-time.

Polystyrene enhanced crystallization of perovskites towards high performance solar cells.

Perovskite solar cells have attracted significant attention due to their high efficiency and low cost. In the research on methylammonium lead-iodide (CHNHPbI), a lot of work has been devoted to optimize the film morphology and crystallinity resulting in an enhancement of the power conversion efficiency (PCE). A good surface coverage and uniform perovskite films are highly desirable along with a smooth and pinhole-free contact between the hole and electron extraction layers.

Host Cell Mimic Polymersomes for Rapid Detection of Highly Pathogenic Influenza Virus via a Viral Fusion and Cell Entry Mechanism.

Highly pathogenic avian influenza virus (HPAIV) infections have occurred continuously and crossed the species barrier to humans, leading to fatalities. A polymerase chain reaction based molecular test is currently the most sensitive diagnostic tool for HPAIV; however, the results must be analyzed in centralized diagnosis systems by a trained individual. This requirement leads to delays in quarantine and isolation.