Porous NiFe-Oxide Nanocubes as Bifunctional Electrocatalysts for Efficient Water-Splitting

Electrocatalytic water-splitting, a combination of oxygen and hydrogen evolution reactions (OER and HER), is highly attractive in clean energy technologies, especially for high-purity hydrogen production, whereas developing stable, earth-abundant, bifunctional catalysts has continued to pose major challenges. Herein, a mesoporous NiFe-oxide nanocube (NiFe-NC) system is developed from a NiFe Prussian blue analog metal–organic framework as an efficient bifunctional catalyst for overall water-splitting. The NiFe-NCs with ∼200 nm side length have a Ni/Fe molar ratio of 3:2 and is a composite of NiO and α/γ-Fe₂O₃. The NCs demonstrate overpotentials of 271 and 197 mV for OER and HER, respectively, in 1 M KOH at 10 mA cm^–2, which outperform those of 339 and 347 mV for the spherical NiFe-oxide nanoparticles having a similar composition. The electrolyzer constructed using NiFe-NCs requires an impressive cell voltage of 1.67 V to deliver a current density of 10 mA cm^–2. Along with a mesoporous structure with a broad pore size distribution, the NiFe-NCs demonstrate the qualities of a desired corrosion-resistant water-splitting catalyst with long-term stability. The exposure of active sites at the edges and vertices of the NCs was validated to play a crucial role in their overall catalytic performance

Electrochemical microfluidic chip composed of a cerium oxide-reduced graphene oxide nanocomposite screen printed carbon electrode (SPCE) for the determination of flunitrazepam

Due to its long-lasting tranquilizing effect on the human body, the abusive use of flunitrazepam (FNZ) in sexual assault and robbery is commonly encountered. In this study, the assembly of a hybrid nanocomposite comprising cerium oxide (CeO2) nanoparticles and reduced graphene oxide (rGO) nanosheets onto the surface of a screen printed carbon electrode (SPCE) is presented for the sensitive determination of flunitrazepam in various beverages. The properties of the CeO2-rGO nanocomposite were evaluated using various spectroscopic and microscopic techniques, while its electrochemical properties were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A distinct composite structure with improved current response and electron transfer properties was achieved through the judicious application of rGO nanosheets to facilitate the in situ formation and anchoring of CeO2 nanoparticles. Under optimal conditions, the CeO2-rGO modified SPCE demonstrated flunitrazepam detection to 124 nM with a sensitivity of 40 µA µM−1 cm−2 and exhibited a broad linear response in the concentration range from 0.1 to 300 µM. The quantification of flunitrazepam in spiked beverage samples using CeO2-rGO/SPCE demonstrated satisfactory recovery from 96 to108%. The functionalized sensor was further integrated into a microfluidic chip to prepare a portable flunitrazepam electrochemical platform, in which multiple samples can be processed and reliable analysis can be conducted at low sample volumes. The designed electrochemical microfluidic platform demonstrated desirable performance for flunitrazepam determination, offering a promising solution for on-site determination of illicit drugs in the field of forensic investigations.</p

CORAL: probing the structural requirements for α-amylase inhibition activity of 5-(3-arylallylidene)-2-(arylimino)thiazolidin-4-one derivatives based on QSAR with correlation intensity index, molecular docking, molecular dynamics, and ADMET studies

The present study aims to examine the structural requirements governing α-amylase inhibitory activity of 5-(3-arylallylidene)-2-(arylimino)thiazolidin-4-one derivatives and their precursors by employing a multifaceted approach combining in vitro and in silico studies. The in vitro assay findings revealed strong inhibitory effect of this class of compounds against α-amylase and compound 20 exhibited maximum percentage inhibition of 88.54 ± 0.69, 84.98 ± 0.40, 77.26 ± 0.75, 67.80 ± 0.54, and 62.93 ± 1.17 at 200, 100, 50, 25, and 12.5 µg mL−1, respectively. Multiple CORAL QSAR models were developed from the randomly distributed eight splits by employing two target functions (TF1, TF2 with WCII = 0.0 and = 0.3, respectively), and the quality of predictions by the produced models was validated with the help of various statistical parameters. The model M-4 (R2Val = 0.8799) and model M-11 (R2Val = 0.9064) were the leading models developed by using TF1 and TF2. We designed five new congeneric inhibitors (D-1 to D-5) by incorporating SMILES features positively correlating with the activity. Molecular docking experiments were carried out to confirm the binding of these new inhibitors with the biological receptor α-amylase (PDB ID: 7TAA). Furthermore, molecular dynamic simulations provided a thorough knowledge of the binding process by shedding insight into the dynamic behavior and stability of the ligand-receptor complex over time. The results of this study highlight the key structural characteristics needed for improved α-amylase inhibitory efficacy and provide a rational basis for the development of more effective inhibitors. Communicated by Ramaswamy H. Sarma</p

Design, synthesis and evaluation of aminothiazole derivatives as potential anti-Alzheimer’s candidates

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Facile synthesis, characterization, and antimicrobial studies of some disubstituted 1,2,3-triazoles with sulfonamide functionality

<p>An expedient synthesis of some 1,4-disubstituted 1,2,3-triazoles (<b>3a–3x</b>) having sulfonamide functionality from various terminal alkynes and aromatic azides through Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition has been reported. The structures of newly synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR, high-resolution mass spectra and screened for in vitro antimicrobial activity against <i>Staphylococcus aureus</i> (Gram-positive bacteria), <i>Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes</i> (Gram-negative bacteria), <i>Candida albicans</i>, and <i>Aspergillus niger</i> (fungi). Some of the synthesized compounds were found to exhibit good potency against above-tested microbial strains. Moreover, to study the binding interactions, docking simulation of broadly active compound <b>3x</b> was also performed against <i>E. coli</i> dihydropteroate synthase enzyme.</p

Interface Engineering-Driven Room-Temperature Ultralow Gas Sensors with Elucidating Sensing Performance of Heterostructure Transition Metal Dichalcogenide Thin Films

In this report, we investigate the room-temperature gas sensing performance of heterostructure transition metal dichalcogenide (MoSe2/MoS2, WS2/MoS2, and WSe2/MoS2) thin films grown over a silicon substrate using a pulse laser deposition technique. The sensing response of the aforementioned sensors to a low concentration range of NO2, NH3, H2, CO, and H2S gases in air has been assessed at room temperature. The obtained results reveal that the heterojunctions of metal dichalcogenide show a drastic change in gas sensing performance compared to the monolayer thin films at room temperature. Nevertheless, the WSe2/MoS2-based sensor was found to have an excellent selectivity toward NO2 gas with a particularly high sensitivity of 10 ppb. The sensing behavior is explained on the basis of a change in electrical resistance as well as carrier localization prospects. Favorably, by developing a heterojunction of diselenide and disulfide nanomaterials, one may find a simple way of improving the sensing capabilities of gas sensors at room temperature

Silicon Carbide Nanocauliflowers for Symmetric Supercapacitor Devices

The efficiency of silicon carbide (SiC) nanocauliflowers (NCs) as electrode material for supercapacitor application has been investigated in detail in the present work. The SiC NCs were deposited on Ag coated porous alumina (AAO) substrates via a DC magnetron cosputtering technique at room temperature. The Ag coated porous AAO substrate acts as an excellent current collector and also enhances the high specific capacitance of SiC NCs up to ∼300 F/g at 5 mV/s. The fabricated symmetric supercapacitor device delivered a high specific capacitance (188 F/g at 5 mV/s), good cycling ability (97.05% capacitance retention after 30,000 cycles), high energy density (31.43 Wh/kg), and also a high power density (∼18.8 kW/kg at 17.76 Wh/kg) in a voltage range of 1.8 V. These observed excellent electrochemical performances of the present SiC NCs based device suggest it has tremendous potential as supercapacitor electrodes in energy storage applications

Additional file 4: Figure S2. of The development of lower respiratory tract microbiome in mice

Represents the mean abundance measure along with the standard error for the individual phyla. (PDF 65 kb

Additional file 2: Figure S1. of The development of lower respiratory tract microbiome in mice

(a) Inverse SDI follows the same trend as the SDI. (b) The table represents the median and inter-quartile range (IQR). (PDF 29 kb

Additional file 7: Figure S5. of The development of lower respiratory tract microbiome in mice

Represents the line plot showing the mean percent abundance measure along with the standard error for the 10 genera. (PDF 180 kb