Absorption Studies Research Articles

Second harmonic generation and reverse saturable absorption in electrospun picric Acid-PMMA nanofibers

Picric acid (PA) – polymethyl methacrylate (PMMA) nanofibers were synthesised using electrospinning technique by optimising all the required parameters. The nonlinear optical behaviour of the synthesised nanofibers was investigated along with their preliminary characterisations like morphological, structural, thermal, mechanical, dielectric and linear optical studies. The nanofibers with average diameter around ∼800 nm, were found to crystallise in Pca21 space group under the orthorhombic crystal system. The incorporation of Picric acid nanocrystals inside the PMMA nanofibers enhanced their tensile strength. Second harmonic generation imaging of picric acid embedded PMMA nanofibers was done by nonlinear microscopy and the emission was confirmed by power dependence as well as Kurtz – Perry powder technique. Nonlinear absorption studies by Z – scan technique were conducted with a Q – switched Nd: YAG laser and the nanofibers exhibited reverse saturable absorption nature at all the input intensities (0.616 × 1012 W/m2, 1.23 × 1012 W/m2 and 2.46 × 1012 W/m2) and the value of the nonlinear absorption coefficient increased corresponding to an increase in input intensity (0.98 × 10−10 m/W, 1.39 × 10−10 m/W and 1.61 × 10−10 m/W) owing to a sequential two photon absorption. Using the transmittance data optical limiting properties of the nanofibers were also analysed and the limiting threshold values (1.92 × 1012 W/m2, 1.80 × 1012 W/m2 and 1.54 × 1012 W/m2) at respective intensities were extracted. The low optical limiting threshold obtained in the present case confirms that picric acid – PMMA nanofibers can be an assured contender as optical limiters in laser safety devices.

Experimental study and analysis of CO2 and SO2 absorption in various water-based nanofluids by response surface methodology

The absorption of acidic gases in the oil and gas industries is important due to their toxicity and corrosive effects. Recently, the application of nanofluids based on aqueous or organic solvents as absorbents has been examined by a variety of researchers. In this study, a single bubble column was exploited to study the effect of water-based nanofluids on the absorption processes of SO2 and CO2 using response surface methodology (RSM) based on Box-Behnken three-level experiment design. With this in mind, CO2 and SO2 are separately injected at the bottom of a bubble column filled with one of the nanofluids: Al2O3-water, SiO2-water, or ZnO-water for each experiment. Then, the rate of SO2 or CO2 absorption in the nanofluids has been elucidated. The effect of important parameters including the weight fraction of the nanoparticles (NPs) (0.01, 0.055, and 0.1 wt.%), gas–liquid contact time (150, 300, and 450 s), and the diameter of nozzle for gas injection (0.46, 0.57, and 0.68 mm) have been studied. Results revealed that the maximum molar flux of both gases was observed in the ZnO-water nanofluid, followed by the SiO2-water nanofluid. In addition, increasing the nanoparticle mass fraction and the bubble size causes the molar flux to rise. However, increasing the gas–liquid contact time causes the molar flux of the mentioned gases to decrease. Finally, a set of the accurate equations has been proposed to predict the molar flux of SO2 and CO2 in the various nanofluids assessed in this work.

Electrical, optical, and structural studies of lithium tungstate-based-phosphate glasses and glass-ceramics

Cathode and electrolyte materials are key components of Li-ion batteries, which influence the safety and electrochemical characteristics. This study focuses on the development and characterization of glassy and glass–ceramic showing either ionic or mixed ionic-electronic conductivity, that can be used as electrolytes or cathodes, respectively, in energy storage devices. Homogenous glasses within the (30 + x)Li2WO4–(70-x)(45.5Li2O–54.5P2O5) system are produced using the melt quenching technique. Structural characterization via XRD and IR spectroscopy revealed diverse structural units. UV–visible absorption studies evaluated optical properties, while impedance spectroscopy measured electrical conductivity. Li2WO4 addition increased density, molar volume, and microhardness. Enhanced electrical conductivity was observed, notably reaching 3.22 × 10−6 (Ω−1 cm−1) at room temperature and 3.13 × 10−5 (Ω−1 cm−1) at 423 K. The richer Li2WO4 materials exhibited ionic conductivity associated to lower activation energy around 0.20 eV. Conductivity’s frequency dependency analysis suggested a correlated barrier hopping mechanism.

Modification of selectively acid-etched halloysite by mucoadhesive chitosan derivatives: New bionanocomposites with improved functional properties

In this study, the modification of selectively acid-etched halloysite (eHal) by low molecular weight chitosan (LChi) and its methacrylated derivative (MeLChi) is investigated to form new bionanocomposites with improved functional properties. The formation of nanocomposites was confirmed by various instrumental techniques (ζ-potential measurements, SEM, FT-IR, DSC, XRD and 1H NMR). Both nanocomposites exhibited improved functional properties while preserving the tubular structure of halloysite. The cytotoxic activity of eHal and eHal-polycation nanocomposites against normal human lung fibroblasts (MRC5) was determined using MTT assay. The results showed good biocompatibility of the prepared nanocomposites, with a cell survival rate of more than 90 %. The mucoadhesive properties of eHal and the corresponding chitosan nanocomposites were investigated in vitro. Primarily, ζ-potential measurements revealed electrostatic interactions between the eHal-polycation nanocomposites and mucin. The absorption study showed that the eHal-MeLChi nanocomposites could adsorb a greater amount of mucin (≈82 %) than the eHal-LChi nanocomposites (≈72 %) and eHal (≈58 %) after 8 h of incubation. Furthermore, the compacts of the tested samples were prepared by direct compression, and the detachment force against the mucin compact was measured using a texture analyzer. A significantly higher detachment force of the eHal-MeLChi nanocomposite compact (1.59 ± 0.07 N) from the mucin compact was determined compared to the eHal-LChi (1.35 ± 0.08 N) and eHal (0.98 ± 0.08 N) samples, demonstrating their improved mucoadhesive potential. In summary, this study demonstrates that functionalization of eHal with MeLChi may be a useful approach for the preparation of nanocomposites as potential carriers for mucoadhesive dosage forms.

2-Amino-4-chlorophenol based Schiff base allied organosilatrane and its silica nanoparticles: Sensing of Cu(II) ion and urease inhibitory activity via spectroscopic and molecular docking study

In this manuscript, 2-amino-4-chlorophenol based Schiff base allied organosilatrane was synthesized using click silylation approach. Then, an astonishing movement was made by encapsulation of compound 5 over silica nanoparticles (Si-NPs) to synthesize hybrid silica nanoparticles acknowledged as AP-NPs and were characterized through various techniques. The colorimetric as well as UV–Vis absorption studies were carried out to recognize the sensing behavior of probes 5 and AP-NPs towards array of metal ions. The probes 5 and AP-NPs detected Cu2+ ion across wide range of other co-existent metal ions recommending highly selective nature. Further, the possible binding modes between ligand 5 and CuCl2 were inspected experimentally through FT-IR and also, approved theoretically by DFT. Moreover, the molecular docking studies were performed to rationalize the highly preferred modes of interaction of ligand 5 with active site of urease.

Achieving High Efficiency and Stability in Organic Photovoltaics with a Nanometer-Scale Twin p-i-n Structured Active Layer.

In pursuing high stability and power conversion efficiency for organic photovoltaics (OPVs), a sequential deposition (SD) approach to fabricate active layers with p-i-n structures (where p, i, and n represent the electron donor, mixed donor:acceptor, and electron acceptor regions, respectively, distinctively different from the bulk heterojunction (BHJ) structure) has emerged. Here, we present a novel approach that by incorporating two polymer donors, PBDBT-DTBT and PTQ-2F, and one small-molecule acceptor, BTP-3-EH-4Cl, into the active layer with sequential deposition, we formed a device with nanometer-scale twin p-i-n structured active layer. The twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device involved first depositing a PBDBT-DTBT:PTQ-2F blend under layer and then a BTP-3-EH-4Cl top layer and exhibited an improved power conversion efficiency (PCE) value of 18.6%, as compared to the 16.4% for the control BHJ PBDBT-DTBT:PTQ-2F:BTP-3-EH-4Cl device or 16.6% for the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl device. The PCE enhancement resulted mainly from the twin p-i-n active layer's multiple nanoscale charge carrier pathways that contributed to an improved fill factor and faster photocurrent generation based on transient absorption studies. The PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl film possessed a vertical twin p-i-n morphology that was revealed through secondary ion mass spectrometry and synchrotron grazing-incidence small-angle X-ray scattering analyses. The thermal stability (T80) at 85 °C of the twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device surpassed that of the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl devices (906 vs 196 h). This approach of providing a twin p-i-n structure in the active layer can lead to substantial enhancements in both the PCE and stability of organic photovoltaics, laying a solid foundation for future commercialization of the organic photovoltaics technology.

Interaction between antidepressant drug trazodone with double-stranded DNA: Multi-spectroscopic and computational analysis

Trazodone (TZD) is an antidepressant drug used to treat major depressive and sleeping disorders. Elevated doses of trazodone are associated with central nervous system depression, which manifests as nausea, drowsiness, confusion, vertigo, exhaustion, etc. To develop a clinically viable active pharmaceutical compound with minimal adverse effects, it is imperative to possess a comprehensive knowledge of the drug's action mechanism on DNA. Hence, we investigate the mode of interaction between trazodone and DNA utilizing various spectroscopic and computational techniques. Studies using UV–vis titration showed that the DNA and trazodone have an effective interaction. The magnitude of the Stern-Volmer constant (KSV) has been calculated to be 5.84 × 106 M−1 by the Lehrer equation from a steady-state fluorescence study. UV–vis absorption, DNA melting, dye displacement, and circular dichroism studies suggested that trazodone binds with DNA in minor grooves. Molecular docking and molecular dynamic simulation demonstrated that the TZD-DNA system was stable, and the mode of binding was minor groove. Furthermore, ionic strength investigation demonstrates that DNA and trazodone do not have a substantial electrostatic binding interaction.

Synthesis, computational and UV–Vis absorption studies of novel sulfathiazole azo sulfonamides acting as potent antitubercular agents

In this work, we have reported the synthesis of unprecedented sulfonamide azo dyes 4(a-j) by the diazo-coupling reaction of sulfathiazole with various coupling components. Different spectroscopic techniques, like FT-IR, NMR (1H and 13C), and HRMS, were used to precisely assess the structures of the target molecules. The UV–Vis absorption study was conducted using variety of organic solvents. Quantum chemical calculations, geometrical optimization, and molecular electrostatic potential regions of all sulfathiazole azo colorants were explored using (DFT)/B3LYP method. The efficacy of the synthesized dyes in combatting M. tuberculosis was examined using the MABA assay; the derivatives 4c and 4h demonstrated promising activity with MIC of 1.56 µg/mL. Further, in silico molecular docking study was performed to elucidate the interactions with enoyl-ACP reductase. Target compounds were screened for their antimicrobial activity using the broth microdilution method against two gram-positive, two gram-negative bacterial strains, and a fungal strain. The cytotoxic potential of the active compounds was assessed using the MTT assay against the Vero cell line.

1,2,3-Triazole appended Schiff base functionalized silanes: A colorimetric sensor of Al (III) and a potent inhibitor of butyrylcholinesterase in Alzheimer’s diseases via molecular docking

The current article reports the synthesis of 1,2,3-triazole appended Schiff base functionalized silanes. The organosilane 7a used for the colorimetric detection of Al (III). The absorption studies have been performed, resulting in a limit of detection values of 1.28 × 10-7 M for the ligand7a.In order to validate the practical applicability of the synthesized probe, the real sample analysis has been performed with aluminium foil in distilled water. Further,the ligand 7a reversibility from [ligand 7a + Al (III)] complex upon EDTA addition can be utilised to build a molecular logic gate, with Al (III) and EDTA considered as inputs and the absorbance intensity at 433 nm considered as the output.The potential binding site of 7a for the Al (III) has been analysed by characterizing the metal–ligand complex using 1H NMR spectroscopy. The cytotoxicity assay of compounds 7(a-c) was performed using SAF-1 (ECACC n°00122301), rendering thenon-toxicity of synthesized compounds. The binding energy of −10.16 Kcal mol−1demonstrated that the ligand 7a is a potent inhibitor for the butyrylcholinesterase enzyme and might be employed as an anti-Alzheimer agent in the future.

Enhanced microwave absorption and mechanical performance of polyvinylidene fluoride thin films embedded with novel activated carbon and manganese ferrite

AbstractThin composite films hold great promise for microwave devices for microwave absorption. This work mainly focuses on the investigation of the microwave absorption and mechanical studies of a composite thin film of activated carbon and manganese ferrite as conductive fillers within a polyvinylidene fluoride (PVDF) matrix. The production of activated carbon was successfully accomplished using a pyrolysis technique. Composite films consisting of polyvinylidene fluoride (PVDF) and activated carbon‐manganese ferrite were fabricated using a solution blending method. The composite films maintained a consistent concentration of activated carbon at 5 wt%. The characterization of the materials was conducted using scanning electron microscopy and X‐ray diffraction. The composite consists of 3 wt% of MnFe2O4 and 5 wt% Activated carbon/PVDF showed exceptional absorption properties and achieved a minimum reflection loss of around −38 dB at a frequency of 8–12 GHz at a thickness of 2 mm. Significantly, the composite film exhibited a greater tensile strength than the PVDF film. The results of our study highlighted the enhanced microwave absorption and economical manufacturing technique for producing composite films. These films exhibit promising microwave‐absorbing properties in stealth applications.Highlights A facile strategy to fabricate thin film PVDF composites was proposed. Novel activated carbon was synthesized to enhance the conductivity. Achieved reflection loss of around −38 dB at a frequency of 8–12 GHz. Synergistic effects of fillers enhanced dielectric and magnetic losses. Exhibited efficient mechanical performance and microwave absorption.

Investigation on the Drug Release Efficacy of the Ibuprofen-Loaded ZIF-8/Fe3O4 NPs Nanocarrier.

In this work, a one-pot multicomponent synthesis of the ibuprofen-loaded Fe3O4 nanoparticles-supported zeolitic imidazolate framework-8 (Ibu-ZIF-8/Fe3O4 NPs) nanohybrid was carried out. The ZIF-8/Fe3O4 NPs nanohybrid was used as a drug carrier for the in vitro release of ibuprofen in a PBS solution. The structure and morphology of the synthesized materials were investigated by powder X-ray diffraction (PXRD) analysis, transmission electron microscopy (TEM) analysis, UV-visible absorption studies, FTIR spectroscopy, and thermogravimetric analysis (TGA). The ibuprofen release kinetics was studied by UV-visible spectroscopy. The mechanism of drug delivery was thoroughly investigated and the Higuchi model was found as the best-fitted model for the ibuprofen release study. The 20 wt % Fe3O4 NPs-supported ZIF-8 nanohybrid exhibited more than 95% ibuprofen release efficiency in phosphate buffer saline of pH 7.4 within 2 h. The separation ability of the nanohybrid was very good, and it was easily separated by a simple commercial magnet. In order to investigate the cell viability, the cytotoxicity of ZIF-8, Fe3O4 NPs, and ZIF-8/20 wt % Fe3O4 NPs was investigated using MTT assays against Leishmania donovani promastigotes. The ZIF-8/20 wt % Fe3O4 NPs nanohybrid carrier exhibited a cell growth inhibition effect with a high correlation coefficient and low probability (p) values. The high release of drug molecules may be due to the more open site of the ZIF-8/Fe3O4 NPs nanohybrid. The drug release profile suggests that the nanohybrid can be potentially used as a drug carrier for targeted drug delivery systems.

Synergistic optimization of physical, thermal, structural, mechanical, optical and radiation shielding characteristics in borate glasses doped with Bi2O3

This paper presents the effect of Bi2O3 on physical, thermal, structural, mechanical, optical, and radiation shielding properties of borate-based glasses having a composition (60-x)B2O3–25Na2O–13BaO-2Gd2O3-xBi2O3; x = 0, 5, 10, 15, and 20 mol%. XRD analysis confirms the amorphous structure of the prepared glasses. As Bi2O3 content increases from 0 to 20 mol%, density of the glasses increases from 2.729 to 3.896 g/cm3, and molar volume rises from 30.947 to 42.017 cm3/mol. The glass transition temperature (Tg) of the samples decreased with Bi2O3 content. FTIR analysis reveals the presence of BO3, BO4, BiO3, and BiO6 structural units in the prepared glasses. Optical absorption studies indicate a decrease in band gap energy from 3.006 to 2.573 eV for indirect transitions implying non-bridging oxygen atom formation and this inference is supported by both physical and FTIR results. The elastic parameters, derived from Makishima-Mackenzie model decreased with increased Bi2O3 concentration suggesting a reduction in mechanical properties. The mass attenuation coefficient (μm), determined through experimental measurements and using Phy-X/PSD software, yielded closely aligned values. Other shielding parameters such as half-value layer (HVL), mean free path (MFP), and effective atomic number (Zeff) were also calculated. The glass containing 20 mol% Bi2O3 exhibited a significant gamma-ray shielding potential due to its high μm value, (0.1260 cm2/g at 0.511 MeV and 0.0960 cm2/g at 0.662 MeV) and Zeff together with low HVL and MFP. A Comparative analysis of the μm values for the present glasses and that of other glasses containing Bi2O3 is also presented.

Optical and EPR spectroscopy of manganese doped LiNaGe4O9 single crystals

The paper presents data on the study of optical absorption, photoluminescence and EPR of lithium-sodium tetragermanate crystals (LiNaGe4O9) doped with Mn ions. Optical spectra were measured in the range 11000–45000 cm−1 and temperatures 77–300 K. They are attributed to manganese in the +4 charge state. From the analysis of optical spectra, the crystal field strength Dq = 2175.2 cm−1 and Racah parameters A = 4065 cm−1, B = 813 cm−1, C = 3239 cm−1 were determined for the Mn4+ ions. The value of the Huang-Rhys factor SFHR = 17.56 indicates a strong electron-phonon interaction of the Mn4+ ion. The presence of Mn4+ ions was further confirmed by measurement of EPR spectra at microwave frequencies 8.9 and 320 GHz. EPR data show that Mn4+ ions occupy two structurally nonequivalent lattice sites with the formation of two Mn4+ centers: Mn1 and Mn2. From the angular dependences of the EPR spectra, the components of the g factor and the hyperfine interaction tensor A, the parameters of the axial D and rhombic E crystal field were determined for both centers. The axial constant D is large for both centers: 0.644 and 0.560 cm−1, respectively. Analysis of optical and EPR spectroscopic data testifies that Mn4+ ions replace the Ge4+ ions in oxygen octahedrons within the host. Structurally nonequivalent centers are attributed to manganese ions located in undistorted lattice sites (Mn1) and in sites perturbed by the LiNa antisite defect (Mn2).

Synthesis, characterization, and MAO inhibitory activities of three new drug-like N-acylhydrazone derivatives

In this study, three new N-acylhydrazone derivatives with the structural motif of N'-(substitutedbenzylidene)-3-(5-methyl-2-benzoxazolinon-3-yl)propanehydrazide (5a-c) are prepared and evaluated for their MAO inhibitory activities. The structures of the synthesized compounds are elucidated through spectral methods (IR, 1H-NMR, 13C-NMR), elemental analysis and single crystal X-ray crystallography. Detailed structural and Hirshfeld surface analyses of compounds (5a-c) have provided further insights into their molecular and crystal structures and also their intermolecular interactions. Complementing the spectral and structural analyses confirmed the E-configurations of the compounds in the solid state. The Hirshfeld surface analyses of the crystal structures have indicated that the most important contributions for the crystal packings are from H ... H, H … C/C … H and H … O/O … H (for 5a-c) and H … F/F … H (for 5b and c). In vitro tests are revealed their MAO inhibitory activities, surpassing reference compounds moclobemide and selegiline. Notably, synthesized N-acylhydrazone derivatives (5a-c) are exhibited superior MAO inhibitory activities, with a higher selectivity for MAOB over MAOA (SI >10). Molecular docking studies are provided insights into the binding modes of the compounds in the active site of the target enzyme. Theoretical ADME (Absorption, Distribution, Metabolism and Excretion), gastrointestinal absorption and blood-brain barrier permeation studies revealed that the compounds possess pharmacological attributes resembling those of typical drugs. This properties and MAO inhibitory activities of N-acyl hydrazone derivatives emphasize their potentials as promising candidates in the field of medicinal chemistry.

Novel antipyrine substituted 4-thiazolidinones: Synthesis, DNA binding and topoisomerase inhibition activities, and in-silico studies

In this study, we report the synthesis and characterization of novel 4-thiazolidinones containing antipyrine (3a-e) derived from the starting compounds of Schiff bases (2a-e). The Schiff bases were synthesized using aldehydes of natural origin, such as citronellal, cuminaldehyde, 2-thiazolecarboxaldehyde, 5-methylfurfural, and syringaldehyde. Their FTIR spectra revealed the enol- tautomeric solid-state structures of compounds 3b and 3d. The pUC18 plasmid DNA binding specificity and capacity of the compounds to catalytically generate topoisomerase I activity were also examined using agarose gel electrophoresis. The compounds induced changes in DNA mobility and showed a topoisomerase I inhibitory effect at all doses. 4-Thiazolidinones had a higher affinity in DNA and topoisomerase I than the Schiff bases. DNA binding and topoisomerase I activities were most effective at low concentration (6 μM) for the compounds of Schiff bases 2a, d, and 4-thiazolidinones 3a, d. Furthermore, this study presents computational methods for addressing the molecules’ drug-like properties. 2a, d, and 3a, d Compounds were used as representative of the most bioactive among the newly synthesized molecules in in-silico studies. The web tools of ADMETlab, SwissADME, OSIRIS, and the BOILED-Egg method were used to conduct in-silico biological studies involving ADME prediction, BBB penetration, gastrointestinal absorption, and toxicity studies. The ADME profile of the query compounds gets within the range of applicability and is at an appropriate level. In-silico studies revealed that compounds 2a, d, and 3a, d are neither hERG blockers nor AMES toxic. However, compounds 2a and 3a have hepatotoxicity.

Probing of CoO-induced nano-sized defects in Li2SO4–MgO–P2O5 glasses: Insights from positron annihilation lifetime spectroscopy

This study investigates the influence of CoO doping on concentration and characteristics of nano-sized cavities in Li₂SO₄-MgO-P₂O₅ glasses using positron annihilation lifetime spectroscopy (PALS). These defects are known to significantly impact the physical properties of glasses. Glasses with compositions of 20 Li₂SO₄-20MgO-(60-x) P₂O₅: x CoO (0 ≤ x ≤ 1.0 mol%), were prepared using melt-quench technique. PALS analysis revealed a strong dependence of positronium (e⁺- e⁻ pair) lifetime on CoO concentration. The analysis of the results further indicated that the fraction of free volume Δf/f0) and cavity radius (R) reached minimum values between 0.6 and 0.8 mol% CoO, but increased with further CoO doping. This suggests that cobalt ions prefer Oh sites, act as network modifiers, and create a larger concentration of free volume defects when CoO is increased beyond 0.8 mol%. Notably, the PALS-derived free volume defect concentration with CoO concentration is found to follow nearly same trend exhibited by the results of optical absorption and AC conductivity studies.

Metabolomic profiling of barley extracts obtained via different solvents and evaluation of their anti-inflammatory efficacy

Barley (Hordeum vulgare L.) stands out for its special nutritional value compared to other cereals, garnering significant attention in recent years. In this study, a comprehensive chemical and biological evaluation of different barley cultivars extracted with different solvents was performed. Ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-QTOF-MS/MS) was used in the phytochemical study. The molecular docking with absorption, distribution, metabolism, excretion, and toxicity (ADMET) study and multivariate analysis alongside the quantification of total phenolic contents (TPC) were performed. Furthermore, the anti-inflammatory action was in vitro assessed by measuring COX-1, COX-2, and 5-LOX inhibition. This study seeks to establish a suitable solvent for extracting anti-inflammatory properties from diverse barley cultivars. The methanol extract obtained from the G.131 cultivar, followed by the 80% methanol extract from the G.136 cultivar, exhibited the most favorable IC50 values in comparison to the reference drugs indomethacin and celecoxib. The phytochemical profile revealed more than 60 compounds that belonged to nitrogen-containing compounds, phenolic compounds, organic acids, flavonoids, and their glycosides, hordatines, and other classes. The TPC and COX-2 inhibition was positively correlated with isoscoparin, coumaroyle–OH–eagmatine, isoorientin, isovitexin 7-O-rhamnosylglucoside, isoscoparin 7-O-glucoside, and isoorientin-7-O-[6-feruloyl]-glucoside. These findings along with their pharmacodynamics study suggested a potential synergistic and significant contribution of these compounds with the anti-inflammatory activity.

Sulfone-infused covalent organic polymer derived from poly(2-aminothiophenol) and erythrosine B as an excellent tool for C–H activation

The generation of a low HOMO-LUMO energy gap makes organic polymer-based composites an important class of materials with outstanding catalytic efficiency. The present work describes the simple and direct synthesis of an excellent photocatalyst, PC (C26H16NO7S)n via doping of erythrosine-B dye on sulfone infused poly(2-amino thiophenol) assembly (PA, (C6H4NO2S)n). The O 1 s spectrum displays peaks at 531.8 eV and 533.3 eV, representing the O=C and O–C groups of the in-situ generated fluorescein loaded on PA surface. Through absorption study (Tauc’s plot), the optical band gap (Eg) for polymer PA (2.9 eV) and photocatalyst PC (2.1 eV) has been calculated. Further, due to the efficient absorbance in the range of 400–600 nm with a low optical band gap, the applicability of the catalyst, PC has been checked in photocatalytic C–H activation in thiophene, and the generation of C–C bond with p-nitro aryldiazonium salt.

Investigating the potential of monocyclic B9N9 and C18 rings for the electrochemical sensing, and adsorption of carbazole-based anti-cancer drug derivatives: DFT-based first-principle study.

For the first time, the use of monocyclic rings C18 and B9N9 as sensors for the sensing of carbazole-based anti-cancer drugs, such as tetrahydrocarbazole (THC), mukonal (MKN), murrayanine (MRY), and ellipticine (EPT), is described using DFT simulations and computational characterization. The geometries, electronic properties, stability studies, sensitivity, and adsorption capabilities of C18 and B9N9 counterparts towards the selected compounds confirm that the analytes interact through active cavities of the C18 and B9N9 rings of the complexes. Based on the interaction energies, the sensitivity of surfaces towards EPT, MKN, MRY, and THC analytes is observed. The interaction energy of EPT@B9N9, MKN@B9N9, MRY@B9N9, and THC@B9N9 complexes are observed - 20.40, - 19.49, - 20.07, and - 18.27kcal/mol respectively which is more exothermic than EPT@C18, MKN@C18, MRY@C18, and THC@C18 complexes are - 16.37, - 13.97, - 13.96, and - 11.39kcal/mol respectively. According to findings from the quantum theory of atoms in molecules (QTAIM) and the reduced density gradient (RDG), dispersion forces play a significant role in maintaining the stability of these complexes. The electronic properties including FMOs, density of states (DOS), natural bond orbitals (NBO), charge transfer, and absorption studies are carried out. In comparison of B9N9 and C18, the analyte recovery time for C18 is much shorter (9.91 × 10-11 for THC@C18) than that for B9N9 shorter recovery time value of 3.75 × 10-9 for EPT@B9N9. These results suggest that our reported sensors B9N9 and C18 make it faster to detect adsorbed molecules at room temperature. The sensor response is more prominent in B9N9 due to its fine energy gap and high adsorption energy. Consequently, it is possible to think of these monocyclic systems as a potential material for sensor applications.

A comparative study of heat absorption and chemical reaction on MHD flow with fractional derivatives

In this article, Caputo and Prabhakar fractional derivatives are used to analyze the influence of heat flux on fractionalized second grade flow. The fluid model is generalized by Fick’s and Fourier’s laws. Moreover, radiation and slip effects are also taken into account additionally. Fractional governing models are solved semi-analytically by using Caputo and Prabhakar fractional derivatives. The method of Laplace method is applied to solve the dimensional model for temperature, velocity, and concentration profiles. The results are contrasted visually. A variety of graphs are used to illustrate the impacts of several parameters, including the heat absorption Q, fractional parameter, magnetic parameter M, and chemical reaction R. It is evident from the figure that the velocity distribution is affected less by chemical and magnetic field, while the fluid velocity is affected more by diffusion-thermodynamics and mass Grashoff number. Furthermore, comparisons among classical and fractional fluid models are made to check the validity of the result. It is noted that the classical approach is less convenient as compared to the fractional approach.