Free Energy Values Research Articles

Synthesis, characterization, and adsorptive performance of titanium dioxide nanoparticles modified groundnut shell activated carbon on ibuprofen removal from pharmaceutical wastewater

In this study, Titanium dioxide Nanoparticles (TiO2 NPs) were biosynthesized using the extract of Cola nitida (Kola nut) pod as a reducing agent. The synthesized TiO2 NPs were impregnated on the surface of Groundnut Shell Activated Carbon (GNSAC) to produce TiO2-NPs-GNSAC, and its performance on the removal of ibuprofen from pharmaceutical wastewater was investigated. The two adsorbents (GNSAC and TiO2-NPs-GNSAC) were characterized using proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET), and Energy Dispersive X-ray (EDX). Physical properties such as moisture content, ash content, and volatile matter content were also determined. The combined effects of three independent variables (temperature, time, and adsorbent dosage) were evaluated in a batch study designed through Box Behnken Design (BBD) of the Response Surface Methodology (RSM) for experimental design, analysis, and process optimization. Regeneration examinations were conducted for three cycles. The proximate analysis showed that GNSAC and TiO2-NPs-GNSAC have 63.21 and 71.11 % of carbon, respectively, which could be attributed to the high organic content in Groundnut Shell (GNS). BET analysis proved that the adsorbents (GNSAC and TiO2-NPs-GNSAC) were mesoporous with mean pore sizes of 6.046 and 5.353 nm, respectively. At optimum conditions of 0.62 g/L, 30 °C and 30 min for adsorbent dosage, temperature, and time, respectively, 68.53 % of ibuprofen was removed using GNSAC, while 81.78 % of ibuprofen was removed at optimum adsorbent dosage, temperature, and time of 0.5 g/L, 30 °C, and 50 min, respectively, using TiO2-NPs-GNSAC. Langmuir isotherm best described the equilibrium data using GNSAC and TiO2-NPs-GNSAC, with maximum monolayer adsorption capacities of 40.82 mg/g and 55.56 mg/g, respectively. Pseudo second-order kinetic model was more suitable to predict the experimental data. The mean free energy (E) values of 0.345 and 0.746 KJ/mol obtained for ibuprofen adsorption onto GNSAC and TiO2-NPs-GNSAC indicate that the mechanism of adsorption of ibuprofen follows the physisorption process. Based on the thermodynamic investigation of the current process, it can be concluded that the adsorption of ibuprofen by the prepared activated carbon (GNSAC and TiO2-NPs-GNSAC) was a spontaneous and endothermic process. Additionally, the adsorbent was successfully regenerated three times, and it was able to perform the adsorption and desorption processes well. Hence, the results of this work suggest that the activated carbon prepared from groundnut shell is a suitable adsorbent for the adsorption of ibuprofen from pharmaceutical wastewater.

Electrochemical and computational insights into the utilization of 2, 2- dithio bisbenzothiazole as a sustainable corrosion inhibitor for mild steel in low pH medium

Industries today place a high premium on environmentally friendly supplies that may effectively inhibit metal dissolution at a reasonable cost. Hence, in this paper, we assessed the corrosion inhibition effectiveness of the Thiazole derivative namely, 2, 2-Dithio Bisbenzothiazole (DBBT) against mild steel (MS) corrosion in 1 M HCl. Several experimental approaches, including gravimetric analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and surface exploration using scanning electron/atomic force microscopy (SEM/AFM) and contact angle (CA), were utilized to conduct the measurements. In 1 M HCl corrosive medium at 298 K in the subsistence of 800 ppm of DBBT, this experiment indicated DBBT as an environment-friendly and sustainable corrosion inhibitor (CI) for MS, demonstrating an inhibition efficiency (IE %) of 97.71%. To deliver a deeper knowledge of the mechanism behind inhibitive behavior, the calculated thermodynamic and activation characteristics were applied. The calculated Gibbs free energy values indicated that the CI interacted physically and chemically with the MS surface, validating physio-chemical adsorption. The findings of the EIS research revealed that an upsurge in the doses of the CI is escorted by an upsurge in polarization resistance (Rp) from (88.05 → 504.04) Ωcm2, and a diminution in double layer capacitance (Cdl) from (97.46 → 46.33) μFcm−2 at (50 → 800) ppm respectively, affirming the inhibitive potential of DBBT. Additionally, the greatest displacement in Ecorr value being 76.13 mV < 85 mV, indicating that DBBT act as a mixed-form CI. To study the further impacts of DBBT on the inhibition capabilities of the compound under investigation, density functional theory (DFT) and molecular dynamics (MD) simulation were employed. Chemical and electrochemical approaches are in agreement with the computational analysis indicating DBBT is the most efficient CI.

Fabrication of bio-polymer-based hydrogel for methylene blue remediation: Kinetics, mechanisms, and environmental implications

ABSTRACT Due to the presence of highly persistent and non-biodegradable dyes that are capable of causing harm to people, plants, animals, and the environment, the treatment of dye-contaminated water tends to be highly challenging. In the current work, polyacrylic acid and bio-polymer-based hydrogels of hydroxyl ethyl cellulose (HEC) were prepared through the free radical polymerization method and were used as adsorbents for the adsorption of methylene blue (MB). To estimate the nature and mechanism of adsorption, kinetics, and isotherm models were adopted. Pseudo-second-order kinetic model was followed by the sorption of MB. Results demonstrated that with an increase in concentration of dye dosage, adsorption increases linearly. Freundlich isotherm model was followed for the sorption of MB onto polyacrylic acid and bio-polymer-based hydrogels. Thermodynamic study of the adsorption process reveals that the adsorption process was spontaneous and endothermic as inferred from Gibbs free energy and enthalpy values of 33.08 kJ/mol and 3.83 kJ/mol at 303K, respectively. Recycling performance was tested and inferred that bio-polymer-based hydrogel having 0.6 gm. Hydroxyethyl cellulose decreases its adsorption efficiency equivalent to 5% after consecutive five cycles. The bio-polymer-based hydrogels will be used as an effective adsorbent for removing cationic dyes from wastewater on an industrial scale.

Smooth Lagrangian Crack Band Model Based on Spress-Sprain Relation and Lagrange Multiplier Constraint of Displacement Gradient

Abstract A preceding 2023 study argued that the resistance of a heterogeneous material to the curvature of the displacement field is the most physically realistic localization limiter for softening damage. The curvature was characterized by the second gradient of the displacement vector field, which includes the material rotation gradient, and was named the “sprain” tensor, while the term “spress” is here proposed as the force variable work-conjugate to “sprain.” The partial derivatives of the associated sprain energy density yielded in the preceeding study, sets of curvature resisting self-equilibrated nodal sprain forces. However, the fact that the sprain forces had to be applied on the adjacent nodes of a finite element greatly complicated the programming and extended the simulation time in a commercial code such as abaqus by almost two orders of magnitude. In the present model, Smooth Lagrangian Crack Band Model (slCBM), these computational obstacles are here overcome by using finite elements with linear shape functions for both the displacement vector and for an approximate displacement gradient tensor. A crucial feature is that the nodal values of the approximate gradient tensor are shared by adjacent finite elements. The actual displacement gradient tensor calculated from the nodal displacement vectors is constrained to the approximate displacement gradient tensor by means of a Lagrange multiplier tensor, either one for each element or one for each node. The gradient tensor of the approximate gradient tensor then represents the approximate third-order displacement curvature tensor, or Hessian of the displacement field. Importantly, the Lagrange multiplier behaves as an externally applied generalized moment density that, similar to gravity, does not affect the total strain-plus-sprain energy density of material. The Helmholtz free energy of the finite element and its associated stiffness matrix are formulated and implemented in a user’s element of abaqus. The conditions of stationary values of the total free energy of the structure with respect to the nodal degrees-of-freedom yield the set of equilibrium equations of the structure for each loading step. One- and two-dimensional examples of crack growth in fracture specimens are given. It is demonstrated that the simulation results of the three-point bend test are independent of the orientation of a regular square mesh, capture the width variation of the crack band, the damage strain profile across the band, and converge as the finite element mesh is refined.

Unified analytical formulation regarding thermodynamic properties subject to gaseous metal hydroxides

Analytical formulations concerning the Gibbs free energy for simple substances and compounds show important applications in dealing with many issues, but acquiring such a formulation with few adjustable parameters remains a challenging goal. Here, we report a unified analytical formulation regarding the Gibbs free energy subject to gaseous metal hydroxides MOH for (M=Al, Be, Cs, K, Li, Mg, Na, Sr, and Ca). It depends only on experimental data of atomic masses and six molecular constants except for an adjustable dimensionless pure number, while the temperature-dependent Gibbs free energy polynomial correlation provided in the National Institute of Standards and Technology (NIST) Chemistry WebBook has eight adjustable coefficients, which take different values in different temperature ranges for each species. The mean relative errors between the predicted Gibbs free energy values subject to nine metal hydroxides and the NIST data are within the range of 0.012 % to 0.078 %, and the predicted results of entropy, enthalpy and isobaric heat capacity are also in good agreement with the NIST data. The proposed unified model possesses the characteristics of high prediction accuracy and strong flexibility.

Influence of antisite defects on two-dimensional polymeric material for improved hydrogen evolution reaction

Two-dimensional materials (2D) supported by single atom catalysis have emerged as effective catalysts for H2 production at large scale by Hydrogen Evolution Reaction (HER). While there is a research surge on utilizing inexpensive metals as catalysts to replace Platinum (Pt) and other related noble metals, their practical limitations such as oxidation issues remain a concern. In this work, we report electrochemical HER activity of a recently synthesized metal-free 2D Polyaramid (2DPA) using Density Functional Theory (DFT) calculations. Pristine 2DPA exhibits remarkable HER performance in terms of active sites availability for hydrogen adsorption and the lowest Gibb's free energy change (−0.06 eV) close to that of benchmark Pt/C catalyst (−0.09 eV). Furthermore, introduction of antisite defects by substituting carbon for nitrogen (CN) and nitrogen for carbon (NC) in pristine 2DPA depicts enhanced HER activity. CN and NC defects tune the electronic properties by reducing the band gap resulting improved conductivity. Low formation energies calculated for obtaining antisite defects confirm their feasibility of synthesis while ab initio molecular dynamics (AIMD) simulations ensure their thermal stability at room temperature. The change in Gibb's free energy (ΔGH) values for CN-defective and NC-defective 2DPA are computed to be −0.13 eV and −0.11 eV, respectively. Both CN-defective and NC-defective 2DPA favor H2 evolution via Heyrovsky reaction pathways due to their relatively lower activation energy, 0.64 eV and 0.51 eV, respectively. Our findings encourage design and development of a novel 2D metal-free electrocatalyst for enhanced HER.

Improvement of corrosion resistance for brass in 3.5% NaCl media by using 4- fluorophenyl-2, 5-dithiohydrazodicarbonamide

Corrosion poses a significant challenge for numerous industries. The use of corrosion inhibitors is essential within these industries. The efficacy of environmentally friendly corrosion inhibitors should remain high even when used at low concentrations. In the present study, the compound 4- fluorophenyl-2,5- dithiohydrazodicarbonamide (FTSC) was used as a corrosion inhibitor for brass in 3.5% NaCl solution. The inhibitor efficiency was determined by using a series of electrochemical techniques such as open circuit potential (OCP), potential dynamic polarisation (PDP), linear polarisation resistance (LPR), and electrochemical impedance spectroscopy (EIS). All experimental tests have been done in stagnant conditions. The findings of the experiments revealed that the compound FTSC looked to be of the cathodic type. Furthermore, the maximum inhibitor efficiency was reached at 98.28% at 1 × 10-3 and at an immersion time of 1 h. The current density was reduced from 16.5 to 0.284 A.cm-2. The adsorption of compound on the brass surface in 3.5% NaCl solution obeyed the Langmuir isotherm with a low negative value of the standard Gibbs free energy of adsorption (-33.8 kJ/mol ΔGads (chemisorption and physisorption). The results confirmed that the compound FTSC can be used as a corrosion inhibitor for brass in 3.5% NaCl.

Variation of CI-2 Conformers upon Addition of Methanol to Water: An IMS-MS-Based Thermodynamic Analysis.

Chymotrypsin inhibitor 2 (CI-2) is a well-studied, textbook example of a cooperative, two-state, native ↔ denatured folding transition. A recent hybrid ion mobility spectrometry (IMS)/mass spectrometry (MS) thermal denaturation study of CI-2 (the well-studied truncated 64-residue model) in water reported evidence that this two-state transition involves numerous (∼41) unique native and non-native (denatured) solution conformations. The characterization of so many, often low-abundance, states is possible because of the very high dynamic range of IMS-MS measurements of ionic species that are produced upon electrospraying CI-2 solutions from a variable temperature electrospray ionization source. A thermodynamic analysis of these states revealed large changes in enthalpy (ΔH) and entropy (ΔS) at different temperatures, and it was suggested that such variation might arise because of temperature-dependent conformational changes of the protein in response to changes in the conformational entropy and the dielectric permeability of water, which drops from a value of ε ∼ 79 at 24 °C to ∼ 60 at 82 °C. Herein, we examine how adding methanol to water influences the distributions of CI-2 conformers and their ensuing stabilities. The dielectric constant of a 60:40 water:methanol (MeOH) drops from ε ∼ 60 at 24 °C to ∼ 51 at 64 °C. Although the same set of conformers observed in water appears to be present in 60:40 water:MeOH, the abundance of each is substantially altered by the presence of methanol. Relative free energy values (ΔG) and thermodynamic values [ΔH and ΔS and heat capacities (ΔCp)] are derived from a Gibbs-Helmholtz analysis. A comparison of these data from water and water:MeOH systems allows rare insight into how variations in solvation and temperature affect many-state protein equilibria. While these studies confirm that variations in solvent dielectric constant with temperature affect the distributions of conformers that are observed, our findings suggest that other solvent differences may also affect abundances.

Leveraging attention-enhanced variational autoencoders: Novel approach for investigating latent space of aptamer sequences

Aptamers are increasingly recognized as potent alternatives to antibodies for diagnostic and therapeutic applications. The application of deep learning, particularly attention-based models, for aptamer (DNA/RNA) sequences is an innovative field. The ongoing advancements in aptamer sequencing technologies coupled with machine learning algorithms have resulted in novel developments. Further research is required to investigate the full potential of deep learning models and address the challenges associated with the generation of sequences, like the large search space of possible sequences. In this study, we propose a workflow that integrates an attention mechanism within a framework of a generative variational autoencoder, to generate novel sequences by expanding latent memory. They show 100 % novelty compared with the dataset, and approximately 88 % of them show negative values for the minimum free energy, which may indicate the likelihood of an RNA sequence folding into a functional structure. Because the field of aptamer discovery is affected by data scarcity, advanced strategies that facilitate the generation of diverse and superior sequences are necessitated. The utilization of our workflow can result in novel aptamers. Thus, investigations such as the present study can address the abovementioned challenge. Our research is anticipated to facilitate further discoveries and advancements in aptamer fields.

Measurement of the solubility and density of the saturated solution of 3-aminophenol in different pure solvents from 283.1 to 323.1 K: Correlative to pure predictive thermodynamic modeling and molecular dynamic simulation

The solubility of 3-aminophenol was measured in water, isopropanol, ethyl acetate, chloroform, and tert-butyl methyl ether (MTBE) from 283.1 to 323.1 K at atmospheric pressure. In addition, the density of pure solvents and the saturated 3-aminophenol solutions was measured. The experimental solubility data were correlated and predicted using four types of thermodynamic models, including correlative (Wilson, NRTL, and UNIQUAC), semi-predictive (NRTL-SAC, and UNIQAUC-SAC), predictive group contribution methods (UNIFAC, and UNIFAC-DMD), and pure predictive COSMO-SAC model. The NRTL-SAC and UNIQUAC-SAC as semi-predictive models were used to obtain 3-aminophenol conceptual segment numbers, and then, using the NRTL-SAC model, the solubility of 3-aminophenol was predicted in 58 FDA approved solvents in the pharmaceutical industry. The predictive models including UNIFAC and UNIFAC-DMD were also used to predict the 3-aminophenol solubility and compared with the experimental data. The results of the COSMO-SAC model have a large deviation from experimental data. In addition, the experimental solubility data were correlated using the PR equation of state with relative success. The segment-based models such as NRTL-SAC and UNIQUAC-SAC are suggested in the fast solvent screening procedure. Finally, the standard dissolution enthalpy (ΔdisH), the standard dissolution entropy (ΔdisS), and the standard dissolution Gibbs energy (ΔdisG) of 3-aminophenol in the selected solvents were calculated by the Van’t Hoff model and the Gibbs-Helmholtz equation. These values imply that the solubility of 3-aminophenol is an entropy-driven non-spontaneous endothermic process in all chosen single solvents. Using the molecular dynamic (MD) simulation the solvation free energy of 3-aminophenol was calculated. The order of the absolute value of free energy of solvation is as ethyl acetate > isopropanol > MTBE > water > chloroform which is consistent with the order of solubility data.

Identification of potential molecular targets and repurposed drugs for tuberculosis using network-based screening approach, molecular docking, and simulation

The spread of drug-resistant strains of tuberculosis has hampered efforts to control the disease worldwide. The Mycobacterium tuberculosis cell wall envelope is dynamic, with complex features that protect it from the host immunological response. As a result, the bacterial cell wall components represent a potential target for drug discovery. Protein-protein interaction networks (PPIN) are critical for understanding disease conditions and identifying precise therapeutic targets. We used a rational theoretical approach by constructing a PPIN with the proteins involved in cell wall biosynthesis. The PPIN was constructed through the STRING database and embB was identified as a key protein by using four topological measures, betweenness, closeness, degree, and eigenvector, in the CytoNCA tool in Cytoscape. The ‘Drug repurposing’ approach was employed to find suitable inhibitors against embB. We used the Schrödinger suites for molecular docking, molecular dynamics simulation, and binding free energy calculations to validate the binding of protein with the ligand. FDA-approved drugs from the ZINC database and DrugBank were screened against embB (PDB ID: 7BVF) using high-throughput virtual screening, standard precision, and extra precision docking. The drugs were screened based on the XP docking score of the standard drug ethambutol. Accordingly, from the top five hits, azilsartan and dihydroergotamine were selected based on the binding free energy values and were further subjected to Molecular Dynamics Simulation studies for 100 ns. Our study confirms that Azilsartan and Dihydroergotamine form stable complexes with embB and can be used as potential lead molecules based on further in vitro and in vivo experimental validation. Communicated by Ramaswamy H. Sarma

Separation potential of 1,5-pentanediol-based deep eutectic solvent: Infinite dilution activity coefficients and excess thermodynamic data

In the present study, the new data of the infinite dilution activity coefficient for 32 different solutes in {1-ethyl-1-methylpyrrolidinium bromide +1,5-pentanediol}, [[EMPYR] Br + 1,5-PDO] DES, were measured using the gas liquid chromatography (GLC) method with pre-saturation of the helium gas. The list of selected solutes included alkanes, alkenes, alkynes, cycloalkanes, cycloalkenes, aromatics, ketones, alcohols, and water. Because the solvents were volatile at the temperatures used for measurements, pre-saturation was deemed necessary. The measurements were taken at temperatures T = (313.15–343.15) K and atmospheric pressure. Values of partial molar properties, i.e., enthalpy, entropy, and Gibbs free energy, were computed at a reference temperature of Tref = 333.15 K. Moreover, the values of capacity and selectivity relating to [[EMPYR] Br + 1,5-PDO] DES for different sets of binary systems that are normally problematic in the separation through solvent extraction or distillation were also computed. These include cyclohexane/benzene; acetone/methanol; and hexane/benzene. The obtained data in the present work was then compared to the literature data, at similar temperatures. Thus, the thermodynamical data is important for pre-selecting solvents for industrial purposes.

Biofilm formation of C. albicans on occlusal device materials and antibiofilm effects of chitosan and eugenol

Microbial adhesion on occlusal devices may lead to oral diseases such as candidiasis. Whether chitosan and eugenol provide antibiofilm effects is unclear. The purpose of this in vitro study was to evaluate the biofilm formation of C. albicans strains on occlusal device materials and the antibiofilm effects of chitosan and eugenol against C. albicans on these surfaces. A total of 88 specimens (5×10×2mm) were produced from occlusal device materials with 4 production techniques: vacuum-formed thermoplastic (Group V), head-press (Group H), computer-aided design and computer-aided manufacture (CAD-CAM) (Group C), and 3-dimensionally (3D) printed (Group D) (n=22). After various finishing procedures, the surface properties of the specimens were evaluated by using surface free energy (SFE), surface roughness (SR) measurements, and elemental and topographic analysis. Biofilm formation of C. albicans strain and the antibiofilm effects of chitosan and eugenol against biofilm formation on these surfaces were also examined with a crystal violet assay. The distribution's normality was statistically analyzed with the Kolmogorov-Smirnov test. One-way and two-way analysis of variance with post hoc Tukey tests were used for statistical evaluations (α=.05). Surface roughness values in Groups D and H were significantly higher than in other groups (P<.05). While the highest surface free energy values (except γp) were in Group V, Group C had the highest γp. The lowest biofilm value appeared in Group H. Chitosan exhibited an antibiofilm effect in all groups except Group H, while eugenol was effective in all groups. The production method affected the susceptibility of occlusal device materials to the adhesion of C. albicans. Eugenol was an effective antibiofilm agent for device materials.

Unravelling benzazepines and aminopyrimidine as multi-target therapeutic repurposing drugs for EGFR V774M mutation in neuroglioma patients

Introduction: Neuroglioma, a classification encompassing tumors arising from glial cells, exhibits variable aggressiveness and depends on tumor grade and stage. Unraveling the EGFR gene alterations, including amplifications (unaltered), deletions, and missense mutations (altered), is emerging in glioma. However, the precise understanding of emerging EGFR mutations and their role in neuroglioma remains limited. This study aims to identify specific EGFR mutations prevalent in neuroglioma patients and investigate their potential as therapeutic targets using FDA- approved drugs for repurposing approach. Methods: Neuroglioma patient’s data were analyzed to identify the various mutations and survival rates. High throughput virtual screening (HTVS) of FDA-approved (1615) drugs using molecular docking and simulation was executed to determine the potential hits. Results: Neuroglioma patient samples (n=4251) analysis reveals 19% EGFR alterations with most missense mutations at V774M in exon 19. The Kaplan-Meier plots show that the overall survival rate was higher in the unaltered group than in the altered group. Docking studies resulted the best hits based on each target's higher docking score, minimum free energy (MMGBSA), minimum kd, ki, and IC50 values. MD simulations and their trajectories show that compounds ZINC000011679756 target unaltered EGFR and ZINC000003978005 targets altered EGFR, whereas ZINC000012503187 (Conivaptan, Benzazepine) and ZINC000068153186 (Dabrafenib, aminopyrimidine) target both the EGFRs. The shortlisted compounds demonstrate favorable residual interactions with their respective targets, forming highly stable complexes. Moreover, these shortlisted compounds have drug- like properties as assessed by ADMET profiling. Conclusion: Therefore, compounds (ZINC000012503187 and ZINC000068153186) can effectively target both the unaltered/altered EGFRs as multi-target therapeutic repurposing drugs towards neuroglioma.

Octahedral Pd3Cu7 Catalysts on Diverse Support Materials for Efficient Hydrogen Evolution: Theoretical Investigation and Mechanistic Perspective.

This work showcases a novel strategy for the synthesis of shape-dependent alloy nanostructures with the incorporation of solid substrates, leading to remarkable enhancements in the electrocatalytic performance. Herein, an aqueous medium approach has been used to synthesize an octahedral PdXCuY alloy of different Pd:Cu ratios to better comprehend their electrocatalytic potential. With the aim to outperform high activity and efficient stability, zirconium oxide (ZrO2), graphene oxide nanosheets (GONs), and hexagonal boron nitride nanosheets (hBNNs) solid substrates are occupied to decorate the optimized Pd3Cu7 catalyst with a minimum 5 wt % metal loading. When compared to the counterparts and different ratios, the Pd3Cu7@hBNNs catalyst exhibited an optimal activity for hydrogen evolution reaction (HER). The lower overpotential and Tafel values observed are 64 and 51 mV/dec for Pd3Cu7@hBNNs followed by Pd3Cu7@ZrO2, which showed a 171 mV overpotential and a 98 mV/dec Tafel value, respectively. Meanwhile, the Pd3Cu7@GONs were found to have a 202 mV overpotential and a 110 mV/dec Tafel value. The density functional theory, which achieves a lower free energy (ΔGH*) value for Pd3Cu7@hBNNs than the other catalysts for HER, further supports its excellent performance in achieving the Volmer-Heyrovsky mechanism path. Moreover, the superior HER activity and sturdier resilience after 8 h of stability may be due to the synergy between the metal atoms, monodisperse decoration, and the coordination effect of the support material.

High-throughput virtual screening approach and dynamic simulation of natural compounds as target inhibitors of BACE1 in Alzheimer's disease

Background Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) protein holds significance in the development of Alzheimer’s disease (AD). This protein is highly expressed in the central nervous system, playing a significant role in the conversion of amyloid precursor protein (APP) into amyloid-beta peptides. The primary objective of the current study was to perform in silico inhibition investigations on this protein, utilizing computational methodologies such as molecular docking and molecular dynamics, to identify novel inhibitors with potential against BACE1. Our focus was on targeting the active site of BACE1, aiming to discover optimal interactions between the ligands and key residues of the target protein. Methods The natural compounds inhibitors data was carefully reviewed from the literature review articles. Molecular docking was conducted using AutoDock Vina with an active site defined by CB-Dock2. We assessed drug-likeness and toxicity using Lipinski’s rule of fives via SwissADME and the ProTox-II web server. Interaction visualization was facilitated using Discovery Studio, while molecular dynamics simulations were performed for 100 nanoseconds with hinokiflavone and BACE1 using Schrodinger LLC Desmond software. Results The molecular docking results showed promising binding affinities and the best binding free energy values were selected, and after conducting Lipinski’s rule of five using SwissADME as well as predicting toxicity using ProTox-II, only one molecule, hinokiflavone was filtered and succeeded in all the analyses to be a potential candidate. Molecular docking results were supported by molecular dynamics simulation. These results demonstrate the stability of the compound in the target protein binding site. Conclusions Finally, these obtained outcomes represent a strong lead to developing promising new natural compound inhibitors against BACE1. For future works, it is essential to concentrate on further experimental validation to ensure the effectiveness of the proposed approach.

A kinetic study of indium, aluminum, arsenic, and strontium extraction from LCDs using biometabolites produced by Aspergillus niger

Waste liquid crystal displays (LCDs) contain significant quantities of both valuable and hazardous metal(loid)s, presenting potential environmental risks alongside valuable opportunities for resource recovery. Biohydrometallurgy holds great promise as a technology widely applicable for dissolving metals from both ores and secondary resources. While recognized for its eco-friendliness and cost-effectiveness, bioleaching faces a challenge in terms of slow kinetics, potentially affecting process efficiency and speed. This study, for the first time, presented a comparative kinetic analysis of metal's bioleaching from end-of-life LCDs by Aspergillus niger, utilizing various rate models. Kinetic evaluation revealed different rate-determining mechanisms for each metal extraction during different time periods, indicating an overall mixed control mechanism between chemical reactivity and diffusion. The reaction rate constants and relevant calculated activation energies showed that the degree of accessibility for element's bioleaching was as follows: As > Al > In > Sr. Thermodynamic variables like activation enthalpy and entropy values determined from the Arrhenius plots at varied temperatures and the results showed that the bioleaching reactions of Al, As, In, and Sr from waste LCDs were endergonic, reactant-favored, non-spontaneous with positive Gibbs free energy values. RSM was used to optimize the interactive effects of parameters that affect the element's extraction rates. The optimal bioleaching parameters were a temperature of 70 °C, and a leaching time of 29 h, which led to the highest extraction of 81.4 % Al, 69.1 % As, 60.0 % In, and 33.3 % Sr from LCD waste under solid/liquid ratio of 10 g/L and shaking speed of 160 rpm. The findings and insights presented in this paper have the potential to advance the field and provide practical guidance for environmentally friendly and economically viable recycling of LCDs.

Electrokinetic properties of healthy and β-thalassemia erythrocyte membranes under in vitro exposure to static magnetic field

Introduction: The current understanding of the biological impacts of a static magnetic field (SMF) is restricted to the direct interactions of the magnetic field with biological membranes. The electrokinetic (zeta) potential is an electrochemical property of erythrocyte surfaces which was negatively charged in physiological media after SMF exposure (0.1‒2.0 T).Methods: The novel data about electrokinetic parameters of the erythrocytes is determined by microelectrophoresis after SMF-exposure in norm and heterozygous β-thalassemia. The methods of light scattering, lipid peroxidation, fluorescence microscopy are used.Results: The electrokinetic potential of erythrocytes in norm is increased after SMF intensities due to enhanced negatively exposed charges on the outer surface of the membrane accompanied by an increase in light scattering where changes in cell morphology are observed. Conversely, a decrease in the zeta potential of β-thalassemia erythrocytes upon SMF-treatment was determined because of the reduction in the surface electrical charge of the membranes, where a significant decrease in light scattering at 1.5 T and 2.0 T was recorded. Exposure to SMF (0.5–2.0 T) was associated with an increase in the malondialdehyde content in erythrocytes. Biophysical studies regarding the influence of SMF on the electrostatic free energy of cells shows an increase in negative values in healthy erythrocytes, which corresponds to the implementation of a spontaneous process. This is also the process in β-thalassemia cells after SMF exposure with lower negative values of free electrostatic energy than erythrocytes in norm.Discussion: The effect of static magnetic field (SMF 0.1–2.0 T) on the electrokinetic and morphological characteristics of erythrocytes in norm and β-thalassemia is determined and correlated with the increase/reduction in surface charge and shrinkage/swelling of the cells, respectively. Lipid peroxidation of healthy and β-thalassemia erythrocytes caused an enhancement of lipid peroxidation because of the higher concentrations of TBARS products in cellular suspension. SMF (0.1‒2.0 T) altered the spontaneous chemical processes with negative values of electrostatic free energy of erythrocytes in norm and β-thalassemia accompanied by a lower FITC-Concanavalin A binding affinity to membrane receptors (SMF 2.0 T). The electrokinetic properties of human erythrocytes in norm and β-thalassemia upon SMF treatment and their interrelationship with the structural-functional state of the membrane were reported. The presented work would have future fundamental applications in biomedicine.

Molecular simulations of understanding the structure and separation thermodynamics of 5-Hydroxymethylfurfural from 1-Butyl-3-Methyl imidazolium tetrafluoroborate

The furfural-based compounds derived from biomass is proven to be reducing greenhouse gas emissions for sustainable chemical processes. 5-hydroxymethylfurfural (5-HMF) is a bio-renewable material that can serve as a significant platform chemical to produce biofuels, green polymers, solvents, etc. Ionic liquids (ILs) have shown promising reaction media to produce 5-HMF from glucose and fructose. However, there is a substantial challenge in separating the 5-HMF from the ILs. In this paper, we use an organic solvent tetrahydrofuran (THF) to understand the molecular level properties of 5-HMF from 1-butyl-3-methyl imidazolium tetra-fluoroborate [BMIM]+[BF4]− using all-atom molecular dynamics simulations. We have analyzed various intermolecular structures, and dynamic and separation thermodynamic properties. Our results show that with an increase in 5-HMF concentration, we observe a favorable intermolecular interaction between 5-HMF and THF compared to the interactions between 5-HMF and [BMIM]+. The 5-HMF presents the dominant intermolecular interactions with cations compared to the anions. The self-diffusion coefficient of 5-HMF shows a decrease in THF and an increase in [BMIM]+[BF4]− with the rise in 5-HMF concentration. The solvation free energy (ΔGsolv) values of 5-HMF in both IL and THF show less negative value with an increase in 5-HMF concentration. The transfer free energy (ΔGtransfer) of 5-HMF (from IL to THF) shows less positive values with an increase in 5-HMF concentration. Overall results presented in this work are promising for understanding the complex interactions between furfural-based compounds and ILs.

Comparative binding effects of celecoxib/ poly(lactic-co-glycolic acid) microparticles with enhancing anti-inflammatory and anti-cancer activities: Density functional theory, molecular Docking, and ADMET calculations

This study is to evaluate the enhancement of anti-inflammatory and anti-cancer activities of celecoxib (CXB) in a dichloromethane (DCM) environment by poly(lactic-co-glycolic acid) (PLGA), using density functional dispersion correction (DFT-D), time-dependent density functional theory (TDDFT), molecular docking (MD), and ADMET calculations. The CXB, via its sulfonamide (-NH2SO2) group contact with the PLGA in state B through hydrogen bonds, is stronger than in states A and C, according to our computed analyses based on binding energy and chemical reactivity parameters. According to the theoretical analysis of IR spectra, the interaction of CXB with PLGA causes shifts in both the pure PLGA and the CXB. In the presence of stronger negative Gibbs free solvation energy (Gsolv) values, the CXB interaction with PLGA results in the increment of dipole moment, higher solubility, and the energy gap (Eg) reduction. Further, MD calculations on states A, B, and C were able to inhibit tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), cyclooxygenase-2 (COX-2), and human epidermal growth factor receptor 2 (HER2). Based on the MD calculations, the obtained data illustrated a strong interaction with the target binding pocket (CXB via the sulfonamide group interacting with PLGA in the state B), leading to the improvement of the anti-inflammatory and anti-cancer activities in comparison with the pure CXB.