Anti-Trypanosomal Potential of The Red Sea Soft Coral Nephthea Mollis Supported by Metabolomic Profiling and Molecular Docking Studies

The total ethanol extract and its derived ethyl acetate fraction of the soft coral Nephthea mollis displayed remarkable in-vitro anti-trypanosomal potential against Trypanosoma brucei with IC50 value of 6.4 and 3.7 (µg/ml, 72 h respectively. Consequently, the total ethanol extract was subjected to LC-HR-ESI-MS metabolomic profiling to discover the constituents that possibly underlie their bioactivities. Therefore, thirty-three secondary metabolites were characterized, among them, sesquiterpenes and diterpenes were found to prevail. In silico modeling was carried out on the dereplicated compounds to provide an insight into their anti-trypanosomal mechanism of action with docking study on ornithine decarboxylase (ORD) which illustrated that five of the dereplicated compounds (‎2-deoxy-12-ethoxy-7-O-methyl lemnacarnol, Nephthenol, ‎4α-O-acetyl-selin-11-en, Eudesma-4,7(11)-diene-8β-ol, and Chabrolidione A) have the highest affinity to the ornithine decarboxylase enzyme. These results highlight the valuable chemical profile of Nephthea mollis as a lead source for anti-trypanosomal natural products.

Mineralogy, Fluid Inclusions, and Isotopic Study of the Kargah Cu-Pb Polymetallic Vein-Type Deposit, Kohistan Island Arc, Northern Pakistan: Implication for Ore Genesis

The Kargah Cu-Pb polymetallic deposit is a newly discovered ore deposit from the Gilgit-Baltistan region, located in the Kohistan Island Arc, northern Pakistan. However, this area is poorly researched on the ore genesis, and its origin and the evolution of its magmatic-hydrothermal system remain unclear. Three stages of mineralization were identified, including quartz-pyrite, quartz-sulfide, and carbonate representing early, middle, and late stages, respectively. The major ore minerals are pyrite, chalcopyrite, galena, and zincian tetrahedrite with minor native silver, and native gold mainly distributed in pyrite. Here, we present a systematic study on ore geology, hydrothermal alterations, trace element composition of pyrite, fluid inclusions, and isotopes (S and Pb) characteristics to gain insights into the nature of the ore-forming fluids, types of unknown deposits, and hydrothermal fluid evolution. The high Co/Ni ratio (1.3–16.4) and Co content (average 1201 ppm), the low Mo/Ni ratio (0.43–0.94) and Mo contents (average 108 ppm) of both Py-I and Py-II suggest a mafic source for the mineralization. The Au-Ni plots, Co-As-Ni correlation, and the δ34S values range from −2.8 to 6.4‰ (average of 3.4‰) indicating the affiliation of the mineralization with a mantle-derived magmatic-hydrothermal provenance. The Pb isotope data showing the narrow variations in 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values suggest a single lead source from crustal-derived materials. The microthermometry data suggest that the dominant mechanisms are fluid boiling and mixing for mineral precipitation at temperatures ranging between 155 and 555 °C, and represent an intrusion-related magmatic-hydrothermal environment for the Kargah Cu-Pb polymetallic deposit.

2D Perovskites for Biological Sensors

2D perovskite’s quantum confinement and superlattices enhance electron and hole recombination which maximizes the photoluminescence quantum efficiency for optical devices. However, only a few works have been reported for biological applications, especially, DNA associated. Contemporary gene-editing science through CRISPR technology is advantageous as all types of nucleic acid chains such as RNA, single-stranded DNA, and double-stranded DNA can be modified. There are numerous reports that base pairs of nucleic acids are nonpolar and 2D perovskites that are capped with aliphatic chains possibly can operate as an optical sensor for detecting a specific sequence of DNA. Here, we demonstrate organic-inorganic halide 2D perovskite’s – capped with eight carbon long aliphatic chains – optical and structural properties. Self-assembly of tin-based perovskites showed near-unity photoluminescence quantum yield but had poor stability in water or ambient condition due to hydrolysis whereas lead-based perovskites showed less PL but were stable in water at high concentration. 2D perovskites’ unique multiple emission peaks at different wavelengths, water stability, and intensity discrepancy when conjugated in nucleoside dispersed solution were studied. However, complex multiple directionalities of PL emission, water stability by concentration, minor PL intensity or wavelength discrepancy, and toxicity followed by the lead source for the perovskites are conflicting with robust and convenient detection technique for the DNA.

Upgrading of methylammonium lead halide perovskite layers by thermal imprint

The manufacturing of devices from methylammonium-based perovskites asks for reliable and scalable processing. As solvent engineering is not the option of choice to obtain homogeneous layers on large areas, our idea is to ‘upgrade’ a non-perfect pristine layer by recrystallization in a thermal imprint step (called ‘planar hot pressing’) and thus to reduce the demands on the layer formation itself. Recently, imprint has proven both its capability to improve the crystal size of perovskite layers and its usability for large area manufacturing. We start with methylammonium lead bromide layers obtained from a conventional solution-based process. Acetate is used as a competitive lead source; even under perfect conditions the resulting perovskite layer then will contain side-products due to layer formation besides the desired perovskite. Based on the physical properties of the materials involved we discuss the impact of the temperature on the status of the layer both during soft-bake and during thermal imprint. By using a special imprint technique called ‘hot loading’ we are able to visualize the upgrade of the layer with time, namely a growth of the grains and an accumulation of the side-products at the grain boundaries. By means of a subsequent vacuum exposition we reveal the presence of non-perovskite components with a simple inspection of the morphology of the layer; all experiments are supported by X-ray and electron diffraction measurements. Besides degradation, we discuss recrystallization and propose post-crystallization to explain the experimental results. This physical approach towards perovskite layers with large grains by post-processing is a key step towards large-area preparation of high-quality layers for device manufacturing.

Synthesis and Characterization of Nanoparticles and Thin Films of PbS by a High-performance Procedure Using CBD

In this research, nanoparticles and nanostructured thin films of lead sulfide are synthesized by using physicochemical methods at room conditions or suchlike conditions, at short reaction times; furthermore, is used simple laboratory equipment and a simplified experimental configuration. Both syntheses do not employ, ammonium or ammonia to elaborate PbS. The main used precursors for both processes are lead acetate, as the lead source, polyethyleneimine as the complexing agent, and thioacetamide, as the sulfur source. Acetylacetone has been employed as a dispersant agent to elaborate PbS nanoparticles. While the sodium hydroxide maintains a high pH, to elaborate PbS thin films. The characterizations reveal the existence of PbS nanoparticles whose size is smaller than 10nm and with a band gap of 3.35 eV. On the other hand, the resulting thin film is made up of PbS little crystallites of 22 nm in a homogeneous way and its band gap is 1.85 eV.

Virtual Screening of the Flavonoids Compounds with the SARS-CoV-2 3C-like Protease as the Lead Compounds for the COVID-19

: As per the1st of September 2020, the COVID-19 pandemic has reached an unprecedented level of more than 25 million cases with more than 850,000 deaths. Moreover, all the drug candidates are still undergoing testing in clinical trial. In this regard, a breakthrough in drug design is necessary. One strategy to devise lead compounds is leveraging natural products as a lead source. Several companies and research institutes are currently developing anti-SARS-CoV-2 leads from natural products. Flavanoids are well known as a class of antiviral compounds library. The objective of this research is to employ virtual screening methods for obtaining the best lead compounds from the library of flavonoid compounds. This research employed virtual screening methods that comprised of downloading the protein and lead compound structures, QSAR analysis prediction, iterations of molecular docking simulation, and ADME-TOX simulation for toxicity prediction. The QSAR analysis found that the tested compounds have broad-spectrum antiviral activity, and some of them exhibit specific binding to the 3C-like Protease of the Coronavirus. Moreover, juglanin was found as the compound with the most fit binding with the Protease enzyme of SARS-CoV-2. Although most of the tested compounds are deemed toxic by the ADME-Tox test, further research should be conducted to comprehend the most feasible strategy to deliver the drug to the infected lung cells. The juglanin compound is selected as the most fit candidate as the SARS-CoV-2 lead compound in the tested flavonoid samples. However, further research should be conducted to observe the lead delivery method to the cell.

Cesium Doping for Performance Improvement of Lead(II)-acetate-Based Perovskite Solar Cells

Lead(II)-acetate (Pb(Ac)2) is a promising lead source for the preparation of organolead trihalide perovskite materials, which avoids the use of inconvenient anti-solvent treatment. In this study, we investigated the effect of cesium doping on the performance of Pb(Ac)2-based perovskite solar cells (PSCs). We demonstrate that the quality of the CH3NH3PbI3 perovskite film was improved with increased crystallinity and reduced pinholes by doping the perovskite with 5 mol% cesium. As a result, the power conversion efficiency (PCE) of the PSCs was improved from 14.1% to 15.57% (on average), which was mainly induced by the significant enhancements in short-circuit current density and fill factor. A PCE of 18.02% was achieved for the champion device of cesium-doped Pb(Ac)2-based PSCs with negligible hysteresis and a stable output. Our results indicate that cesium doping is an effective approach for improving the performance of Pb(Ac)2-based PSCs.

Novel scalable aerosol-assisted CVD route for perovskite solar cells

A perovskite solar cell is produced using the scalable technique aerosol-assisted chemical vapour deposition for the first time. This is achieved by using a 2-step process with lead acetate as the lead source and methanol as the solvent.