Nanoformulation of Glycyrrhizic acid as a potent antiviral agent against Covid-19

In many previous studies, it has been found that liquorice plant (Glycyrrhiza glabra) extracts contain more than 300 natural compounds, most of which are triterpenoids and flavonoids, and had shown promising results in clinical studies for treating many microbial and viral infections. Triterpenoids like glycyrrhizic acid have shown anti-SARS-CoV activity in- vitro. Experimentally, certain glycyrrhizic acid derivatives have shown increased activity by many folds against SARS-associated viruses. These compounds can potentially inhibit the replication cycle of SARS-associated viruses by interfering with the viral gene expression or by inhibiting the spike protein expression, which in turn inhibits the adhesion and entry of the virus. Although the therapeutic has shown great antiviral activity in vitro, but in vivo its efficiency deteriorates till it reaches the liver for metabolism. In the current review, we analyze the unique replication strategy of SARS-CoV-2 and glycyrrhizic acid as a potential drug against SARS-CoV-2. We also discuss possible nano-formulations of glycyrrhizic acid for efficient drug delivery in humans, as a potent therapeutic strategy for COVID-19.

Evaluation of rare-earth sesquioxides nanoparticles as a bottom-up strategy toward the formation of functional structures

Background: The strategy to form functional structures based on powder technology relies on the concept of nanoparticles characteristics. Rare-earth sesquioxides (RE2O3; RE as Y, Tm, Eu) exhibit remarkable properties, and their fields of application cover energy, astronomy, environmental, medical, information technology, industry, and materials science. The purpose of this paper is to evaluate the RE2O3 nanoparticles characteristics as a bottom-up strategy to form functional materials for radiation dosimetry. Methods: The RE2O3 nanoparticles were characterized by the following techniques: XRD, SEM, PCS, FTIR, ICP, EPR, and zeta potential. Results: All RE2O3 samples exhibited cubic C-type structure in accordance with the sesquioxide diagram, chemical composition over 99.9%, monomodal mean particle size distribution, in which (d50) was inferior than 130nm. Among all samples, only yttrium oxide exhibited EPR signal, in which the most intense peak was recorded at 358mT and g 1.9701. Conclusion: The evaluation of nanoparticle characteristics is extremely important taking into account a bottom-up strategy to form functional materials. The RE2O3 nanoparticles exhibited promising characteristics for application in radiation dosimetry.

Carbon Nanotubes based composites for electromagnetic absorption- A review

: Radar is a delicate detection device and since its evolution different techniques for reducing electromagnetic reflections have been discovered. This paper provide concise review on fundamentals of absorption which reduces radar cross section from stealth target with which radar cross section has effects to survivability and mission capability. The reduction of radar cross section depend on dielectric and magnetic properties of material. The first section reviews the Radar Absorbing Material (RAM) in order to provide a background on fundamentals, various stealth techniques for absorption and its properties at microwave frequencies. The second section reviews the Multi-Walled Carbon Nanotubes and its different composites by encapsulation of other metals, polymers or epoxies into it and its microwave absorption properties were studies at microwave frequencies. Multi-Walled Carbon Nanotubes based composites for microwave absorption are reviewed on the basis of various factors; material composition, reflection loss performance, thickness, complex permittivity, complex permeability, dielectric tangent loss, magnetic tangent loss, bandwidth, and frequency band.

Synthesis and blue emission properties of Co-doped CdS semiconductor nanoparticles

Background: Cadmium sulfide (CdS) based semiconductors are of great interest for different high-end applications because it poses direct bandgap (2.42 eV). CdS are the primary constituent material in many applications, namely solar cells, electroluminescent, and quantum dot light-emitting diodes. Transition metal-doped CdS revealed considerable influence in the bandgap, photoluminescence properties, and peak energy upon increasing the metal content. Objective: In this work, we study the single-phase cubic structure of CdS. Photoluminescence spectra revealed a strong blue emission peak located at about 445 nm. Methods: We investigate the Co-doping CdS semiconductor nanoparticles prepared via the chemical co-precipitation method using thiophenol as a template, 300 °C/2h in vacuum optimum temperature, and annealing period to yield nanosized particles. Morphology and structural studies of the particles were using XRD and TEM, respectively. Results: XRD and TEM studies for the calcined samples revealed a cubic structure. The crystalline size was in the range of 10-17 nm. Thermo gravimetric analysis (TGA) was employed to stabilize the temperature of annealing for the samples. Photoluminescence spectra revealed a strong blue emission peak around 445 nm, indicating surface states within the band gap region, a characteristic feature of nanoparticles. The blue shift in the spectra and the band gap value of Co-doped CdS nanoparticles was estimated using UV-vis absorption spectra. Conclusion: XRD analysis indicated zinc blende structure, and the intensity decreased with increasing Co content. TEM images show that the particles are spherical with average sizes around 13 nm. Luminescence of the synthesized nanoparticles exhibited blue emission between 400 – 500 nm, with the peak located at about 445 nm. The emission intensity increased with the increase in Co concentration.

Pure PZT95/5 ceramics and its phase transition behavior under external fields

Background: Compositionally modified Pb(Zr0.95Ti0.05)O3 (PZT 95/5) ferroelectric materials are extensively investigated in past decades for many important applications. However, few pure PZT95/5 ceramics were reported. Objective: Herein, pure PZT95/5 ceramics were successfully prepared and their microstructure, phase transition behaviors under external fields were studied. Method: Pure PZT95/5 ceramics were prepared by conventional solid state reaction using a mixed oxide route. The microstructure and its properties under different external fields were measured. Results: The X-ray diffraction patterns indicate that the virgin pure PZT95/5 ceramics exhibit an orthorhombic antiferroelectric phase, also evidenced by the superlattice reflections in SAED pattern. While a rhombohedral ferroelectric symmetry crystal structure was observed in the pooled samples suggesting that an electric field induced antiferroelectric to ferroelectric phase transition occured. Pure PZT95/5 ceramics exhibited a quenched ferroelectric hysteresis loop with a remnant polarization of ~8μC/cm2 under 3.5kV/mm. Temperature dependence dielectric response indicated that orthorhombic antiferroelectric to cubic paraelectric phase transition occured at 225oC, corresponding to its Curie temperature. A shard depolarization behavior and dielectric anomalies were observed under ~240 MPa hydrostatic pressure. Conclusions: The depolarization mechanism of pure PZT95/5 ceramics under hydrostatic pressure is attributed to the hydrostatic pressure induced FE-AFE phase transition. These results will offer fundamental insights into PZT95/5 ceramics for pulsed power supply applications.

Benzotriazacycle Cored Perylene Diimide Non-fullerene Acceptors for High-performance Organic Solar Cells

Background: Perylene diimide (PDI) is among the most investigated non-fullerene electron acceptor for organic solar cells (OSCs). Constructing PDI derivatives into three-dimensional propeller-like molecular structures is not only one of the viable routes to suppress the over aggregation tendency of the PDI chromophores, but also raises possibilities to tune and optimize the optoelectronic property of the molecules. Objective: In this work, we reported the design, synthesis, and characterization of three electron-accepting materials, namely BOZ-PDI, BTZ-PDI, and BIZ-PDI, each with three PDI arms linked to benzotrioxazole, benzotrithiazole, and benzotriimidazole based center cores, respectively. Method: The introduction of electron-withdrawing center cores with heteroatoms does not significantly complicate the synthesis of the acceptor molecules but drastically influences the energy levels of the propeller-like PDI derivatives. Result: The highest power conversion efficiency was obtained with benzoxazole-based BOZ-PDI reaching 7.70% for its higher photon absorption and charge transport ability. Conclusion: This work explores the utilization of electron-withdrawing cores with heteroatoms in the propeller-like PDI derivatives, which provides a handy tool to construct high-performance non-fullerene acceptor materials.

2D and Layered Ti-based Materials for Supercapacitors and Rechargeable Batteries: Synthesis, Properties, and Applications

: Titanium-based two-dimensional (2D) and layered compounds with open and stable crystal structures have attracted increasing attention for energy storage and conversion purposes, e.g., rechargeable alkali-ion batteries and hybrid capacitors, due to their superior rate capability derived from the intercalation-type or pseudocapacitive kinetics. Various strategies, including structure design, conductivity enhancement, surface modification, and electrode engineering, have been implemented to effectively overcome the intrinsic drawbacks while simultaneously maintaining their advantages as promising and competitive electrode materials for advanced energy storage and conversion. Here, we provide a comprehensive overview of the recent progress on Ti-based compound materials for highrate and low-cost electrochemical energy storage applications (mainly on rechargeable batteries and supercapacitors). The energy storage mechanisms, structure-performance relations, and performanceoptimizing strategies in these typical energy storage devices are discussed. Moreover, major challenges and perspectives for future research and industrial application are also illustrated.