Behavior Of Complexes Research Articles

Measuring Irreversibility from Learned Representations of Biological Patterns

Thermodynamic irreversibility is a fundamental characteristic of living matter, crucial for maintaining the complex spatiotemporal structures and functions that define biological systems. However, accurately quantifying biologically relevant irreversibility remains challenging due to noise and nonlinear interactions among many degrees of freedom. Here, we employ deep learning techniques to identify tractable, low-dimensional representations of phase-field patterns in a canonical protein signaling process—the Rho-GTPase system—as well as in complex Ginzburg-Landau dynamics. We demonstrate that factorizing variational autoencoder neural networks can robustly extract informative pattern features despite noise. These neural-network-derived representations reveal signatures of mesoscopic broken detailed balance and time-reversal asymmetry in both Rho-GTPase and complex Ginzburg-Landau wave dynamics. By applying the compression-based Ziv-Merhav estimator to these representations, we successfully recover irreversibility trends across complex Ginzburg-Landau patterns, which vary widely in spatiotemporal frequency and noise level. Our irreversibility estimates also recapitulate cell-activity trends in Rho-GTPase patterns subjected to metabolic inhibition. Furthermore, our framework distinguishes between stable and chaotic dynamical phases in these nonlinear systems. By leveraging advances in deep learning, our approach provides robust, model-free measurements of nonequilibrium and nonlinear behavior in complex living processes. Published by the American Physical Society 2024

Preparation, characterization and heat release behavior of inclusion complexes formed between carvone or limonene and acyclic cucurbit[n]urils.

Carvone and limonene are naturally occurring monoterpenoids with unique aromas, making them valuable substances in synthetic fragrance production. However, their application is limited due to low stability and rapid volatilization. To address this challenge, host-guest complexes offer a promising solution. In this study, two acyclic cucurbit[n]urils were synthesized to form inclusion complexes with carvone and limonene, aiming to enhance their thermal stability and achieve excellent heat release properties. The binding behavior of the complexes was investigated using NMR, X-ray diffraction (XRD), Fourier transform infrared (FTIR) and molecular bonding analyses, confirming the formation of host-guest inclusion complexes. Our study successfully prepared four inclusion complexes (M1/CA, M2/CA, M1/LI, M2/LI) and characterized them using NMR, XRD and FTIR techniques. These complexes exhibited a 1:1 stoichiometric ratio, and their binding constants were determined through fluorescence titration. The thermal controlled release experiment shows that the degree of carvone and limonene release is different with a change of temperature, indicating that the inclusion complexes have good thermally controlled release performance, and the thermal release retention rate has a certain correlation with KS value. The larger the KS value, the higher the thermal release retention rate of the inclusion complexes, the lower the volatilization of the inclusion complexes, the longer the retention time and the better the thermal stability. This study presents a novel approach for developing carvone- and limonene-based fragrances, expanding their application potential in various industries. © 2024 Society of Chemical Industry.

Osmium(III) Acetylacetonate and Its Missing Polymorph: A Magnetic and Structural Investigation.

Despite the potential for their application, the magnetic behavior of complexes containing 4d and 5d metal ions is underexplored, evidencing the need for benchmark multi-technique studies on simple molecules. We report here a structural and magnetic study on osmium(III) acetylacetonate [Os(acac)3]. X-ray single crystal diffraction did not allow us to determine the structure of the β-polymorph of [Os(acac)3]. The combined magnetic (dc magnetic measurements on powder and cantilever torque magnetometry on single crystal) and spectroscopic (electron paramagnetic resonance, EPR) characterization is here used to provide further evidence that its structure is indeed the one of the orthorhombic "missing polymorph", analogous to the ruthenium(III) derivative. Our study shows that all acetylacetonate complexes of the eighth group of the periodic table show dimorphism and are isomorphic. The EPR characterization allowed the experimental assessment of the easy axis nature of the ground doublet and the determination of the first hyperfine coupling in an osmium complex. Torque magnetometry, applied here for the first time on an osmium-based molecule, determined the orientation of the easy axis along the pseudo C3 axis of the complex. Ac magnetometric measurements revealed in-field slow relaxation of the magnetization further slowed by the suppression of dipolar fields via magnetic dilution in the isostructural gallium(III) analogue.

An Integrative Computational Approach for Design and Evaluation of Novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole Analogues as Dual-Action Anti-Retroviral and Anti-Bacterial Agents: Insights into Rational Drug Design Strategies

The development of effective antiretroviral inhibitors (HIV-1 Reverse Transcriptase) and glucosamine-6-phosphate (GlcN6P) agents represent a significant challenge for combating viral infections and related diseases. In this study, we employed a multidisciplinary approach to design and evaluate a series of novel triazole analogs as potential candidates for anti-retroviral and glucosamine-6-phosphate agents. Using molecular docking, we explored the binding interactions between the RSA3 analog and the target proteins implicated in viral replication and glucosamine metabolism. Density functional theory (DFT) employing the 6-311++G(d,p) basis set was utilized for computational analysis, with a subsequent examination of the electronic parameters. The HOMO and LUMO orbitals as well as the molecular electrostatic potential map were investigated using DFT to characterize the reactivity of our molecule. Molecular dynamics simulations were performed to investigate the stability and dynamic behavior of the ligand-protein complex (RSA3) over time (300 ns). Furthermore, we employed MM-GBSA calculations of the compound RSA3 (molecular mechanics generalized band surface area) to estimate the binding free energies (−71.30 ± 7.26 kcal/mol and −67.86 ± 7.09 kcal/mol, respectively) and identified the most promising compounds with high affinity for the target proteins. Additionally, predictive absorption, distribution, metabolism, excretion and toxicity (ADMET) studies of compound RSA3 were conducted to assess its drug-like properties and potential safety profiles of the selected compound. Our results revealed that RSA3 has favorable binding interactions, is a stable complex and has significant binding affinity for target proteins. Moreover, predictive ADMET studies indicated that RSA3 possesses desirable drug-like properties, suggesting its potential for further investigation as an anti-retroviral agent and glucosamine-6-phosphate agent. Overall, this integrative computational approach combining molecular docking, DFT analysis, dynamics simulations, MM-GBSA and predictive ADMET studies provides valuable insights into the design and evaluation of novel triazole analogs with potential therapeutic applications, highlighting the importance of rational drug design strategies in the field of antiretroviral and glucosamine research.

Diorganotin(IV) derivatives of ONO tridentate Schiff bases: Synthesis, spectroscopic characterization, DFT studies, CT-DNA binding, and plasmid-DNA cleavage studies

Two Schiff bases 2-amino-N'-(5‑bromo-2-hydroxybenzylidene)-3-(4-hydroxyphenyl)propanehydrazide (H2L1) and 2-amino-N'-(5‑chloro-2-hydroxybenzylidene)-3-(4-hydroxyphenyl)propanehydrazide (H2L2) and their six diorganotin(IV) complexes (R = C4H9 (1, 4), CH3 (2, 5), and C8H17 (3, 6)) have been synthesized. Schiff bases (H2L1–2) and their R2SnL1–2 complexes (1–6) have been characterized by CHNS analysis, IR spectroscopy, 1H, 13C, 119Sn NMR, and ES-MS. Schiff bases (H2L1–2) act as a dianionic tridentate ligand coordinated to Sn through phenolic and enolic oxygen and azomethine nitrogen in R2SnL1–2 complexes (1–6). A density functional theory (DFT)-based quantum chemical calculation validated the structures of R2SnL1 (1–3) and R2SnL2 (4–6) at the B3LYP/6‐311G(df,pd)/Def2‐SVP(Sn) and B3LYP/6‐31G(d,p)/Def2‐SVP(Sn) levels of theory, respectively. At these levels of theories, comprehensive electronic structure calculations determined atomic charges at selected atoms. Additionally, a molecular electrostatic potential (MEP) map identified electrostatic potential-varying sites on the molecule's surface, and MEP maps used to identify regions where other molecules might interact or react with the molecules on them. Furthermore, a conceptual-DFT-based global reactivity descriptor determined the stability and reactivity behaviour of R2SnL1–2 complexes (1–6). H2L1–2 and R2SnL1–2 complexes (1–6) have binding constants in the range ∼105 M-1 with CT-DNA, as revealed by UV–visible and fluorescence spectral titrations. UV-visible, fluorescence spectroscopy, and CD studies suggested that H2L1–2 and their R2SnL1–2 complexes (1–6) interact with CT-DNA electrostatically or groove-bound. DNA cleavage studies reveal that H2L1–2 and their R2SnL1–2 complexes (1–6) have ability to cleave the plasmid-DNA from its supercoiled form (SC, I) to nicked form (NC, II). However, n-Bu2SnL2 (4) and n-Oct2SnL2 complex (6) have higher cleavage activity than Schiff bases and other R2SnL1–2 complexes (1–6).

Microwave freeze-drying characteristics and crosslinking behavior of wheat starch-laurel acid complex

This article investigates the effect of different microwave powers on the crosslinking behavior and microwave freeze-drying characteristics of wheat starch-lauroyl arginate complex during the microwave freeze-drying process. During microwave freeze-drying, as microwave power increased from 0.1 W/g to 0.9 W/g, the freeze-drying time of WS-LA was reduced by 50 %, while the uniformity of freeze-drying was not affected by its composition. In the research results obtained from DSC, Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), XRD, and SEM analyses, with the microwave power increased from 0.1 W/g to 0.9 W/g, the enthalpy value of the melting peak of the WS-LA (wheat starch-lauric acid) composite decreased from 1.15 J/g to 0.62 J/g. The full width at half maximum (FWHM) value increased from 25.6 to 30.79. The ratio of absorbance at 1022/995 cm−1 increased from 1.0111 to 1.0707. The recrystallization (RC) value decreased from 8.77 % to 0.07 %. Additionally, in the microstructure, the size of WS-LA composite particles decreased accordingly. The above findings indicated that the increase in microwave power during microwave freeze-drying had a negative impact on the formation of the WS-LA complex and the ordering of its structure in the sample.

Antimigraine activity of Asarinin by OPRM1 pathway with multifaceted impacts through network analysis

Migraine is a debilitating neurological disorder impacting millions worldwide. Calcitonin Gene-Related Peptide (CGRP) has emerged as a key player in migraine pathophysiology, leading to the development of targeted therapies. This study reviews novel CGRP-targeted treatments, including monoclonal antibodies small molecule inhibitors/nutraceuticals and introduces Asarinin as a potential modulator of the pathway. Asarinin, a natural compound found in various plants, is examined for its pharmacological potential in migraine management. Pharmacokinetic assessments, toxicological modelling, molecular property analysis, and network pharmacology were conducted. Molecular docking and dynamics studies with CGRP reveal potential interactions, providing a foundation for understanding Asarinin's therapeutic effects. Asarinin's favourable pharmacokinetics, safety profile, and bioactivity, supporting its candidacy as a therapeutic agent. In-depth molecular docking studies with the CGRP receptor (PDB: 6ZHO) demonstrate strong binding affinity (− 10.3kcal/mol), while molecular dynamics simulations unveil the dynamic behavior of the Asarinin-CGRP complex, (− 10.53 kcal/mol) for Atogepant-CGRP complex. Network analysis highlights key proteins in migraine pathology, indicating Asarinin's potential efficacy. The groundwork for future investigations, suggests Asarinin as a promising candidate for migraine management by targeting OPRM1 pathway. The integration of diverse assessments provides a comprehensive understanding of Asarinin's potential and paves the way for further preclinical and clinical research.

Heterobimetallic Cu(I)/Fe(II) azomethine bridged coordination-organometallic hybrid complexes: Synthesis, luminescence, electrochemical and catalytic properties

A new series of heterobimetallic complexes of the type [Cu(L)(PPh3)2]X (1–4) [where L = trans-4-(ferrocenylideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one; PPh3 = triphenylphosphine, X = NO3−(1), ClO4− (2), BF4− (3) , PF6− (4)] were prepared by reaction of L with [Cu(MeCN)2(PPh3)2]X and characterized by elemental analysis, FTIR, 1H NMR, 31P NMR and UV–visible spectral studies. The thermal stability of (1–4) has been investigated by using thermogravimetric analysis (TGA). X-ray powder diffraction of the representative complex 1 used to clarify the crystal structure of the complex. The electrochemical behaviour of complexes (1–4) displayed quasireversible redox behaviour corresponding to Cu(I)/Cu(II) and Fe(II)/Fe(III) couples. All complexes show red emission as a result of ligand-ligand charge transfer (LLCT) and metal-ligand charge transfer (MLCT) or admixture of them. The catalytic efficiency of the complexes (1–4) was tested and it was found that the complex 4 worked as an effective catalyst for the C-N coupling reaction of aromatic amines and aryl halides.

Molecular motion behaviors of starch affect starch-polyphenol inclusion complex and digestibility among different stilbenes polyphenol structures

Starch-polyphenol V-type inclusion complex has become a hot topic due to its anti-digestibility and nutritional function. This paper aimed to explore the molecular motion behavior of starch affects starch-polyphenol inclusion complex and digestibility among different stilbene polyphenol structures (resveratrol (RA), pterostilbene (PB) and polydatin (PD) via the high-pressure homogenization (HPH) and heat moisture treatment (HMT) processes), which represented the fully extended and limited molecular motion behavior of starch, respectively. These results revealed distinct trends in complex formation among different stilbenes polyphenol structures, highlighting RA as particularly conducive to increasing single helix and V-type crystalline structures with the highest resistant starch (RS) content of 28.11 % due to its smaller steric hindrance. Novelty, in HPH environments with extended molecular motion behavior, the steric hindrance and hydrophobicity/CH-π interactions of polyphenols influence complex formation in the order of RA > PB > PD. Conversely, in HMT systems with limited molecular motion behavior, the limited movement of molecules emphasized the importance of hydrogen bond interactions between polyphenols and starch. Thus, the glucoside in PD enhanced its interaction with starch compared to methoxy-modified PB, leading to increased formation of inclusion complex with RS content of 18.61 %. Overall, these findings deepen the understanding of starch-polyphenol interactions.

Study on Parking Adaptability in Urban Complexes on Top of Subways Based on Shared Parking Spaces

Urban complexes on top of subways as a function of intensive building groups, including residential, office, business, and other types nature of land use where parking time differences are obvious, can implement shared parking spaces, thereby reducing the index of parking allotment. Currently, the parking space allocation index for complexes is only a simple superposition of different land uses, resulting in an over-allocation of parking allotments, leading to a waste of land resources and a low utilization rate of parking allotments. Considering the factor of shared parking spaces, this paper conducted an in-depth analysis of the parking adaptability of urban complexes on top of subways and selected five urban complexes on top of subway stations in Wuhan to conduct a parking survey to analyze the parking demand characteristics. This study also investigated the parking behavior of parkers and analyzed the characteristics of parking behavior in urban complexes on top of subways as well as the current parking demand prediction methods and models, establishing a parking demand prediction model based on shared parking spaces and conducting an adaptability analysis. Finally, using five urban complexes in Wuhan as examples, the number of parking spaces demanded by urban complexes on top of subways in 2025 was predicted, and Wuhan Golden Harvest Fashion Plaza was used as an example to verify the feasibility and implementation ability of the theoretical and applied research in this paper.

Effect of polyelectrolyte (PAA) on the dynamics of weakly charged microemulsion droplets in acidic medium

We use the dynamic light scattering technique (DLS) to study the dynamic behavior of complex constituted by weakly charged microemulsion in the presence of polyelectrolyte. We investigated the impact of adding oppositely charged polyacid (PAA), which is a pH-dependent polyelectrolyte, on the dynamics of charged microemulsion nanodroplets in an acidic medium at pH = 4.5 when the polyacrylic acid are partially charged. In a diluted regime, two diffusive relaxation modes are seen when adding (upon addition) the polyacrylic acid PAA to the microemulsion nanodroplets due to collective diffusion and self-diffusion fluctuations. In the concentrated regime, we observed three diffusive relaxation modes when charged microemulsion nanodroplets complexed with oppositely charged polyacrylic acid. We attribute the two first relaxation modes to the collective diffusion (fluctuation of concentration) and self-diffusion of the microemulsion nanodroplets. The third mode which is a slower relaxation mode; we attribute this relaxation process to the motion of the network formed by the polyacid PAA and microemulsion nanodroplets, or “breathing mode” of the network.

Tribological behavior of a Ti42Nb42Mo6Fe5Cr5 complex concentrated alloy and prediction through response surface methodology based mathematical modeling

In the present work, a novel Ti42Nb42Mo6Fe5Cr5 complex concentrated alloy (CCA) was developed using the vacuum arc melting technique. The as-cast CCA underwent a two-stage heat treatment process. In the first stage of heat treatment (HT 1), the alloy was heated to 900˚C. Subsequently, in the second stage of heat treatment (HT 2), the HT 1 samples were annealed at various temperatures, including 700˚C, 900˚C, and 1100˚C, for 20 h. The microstructure and mechanical response of the as-cast, HT 1 and HT 2 (annealed) samples were thoroughly investigated. The phase evolution, microstructure, and chemical composition were analyzed using XRD and SEM-EDS. The XRD analysis revealed major solid solution BCC phases (BCC 1 and BCC 2) with a small amount of Laves phase; however, the amount of Laves phase increased with increase in annealing temperature. The microhardness and elastic modulus of the CCA specimens were evaluated using instrumented micro-indentation. The CCA annealed at 1100˚C exhibits the highest microhardness and elastic modulus, with values of 5.94 ± 0.38 GPa and 124.40 ± 7.17 GPa, respectively. Response surface methodology (RSM) was used to develop a mathematical model aimed at predicting tribological characteristics, specifically the specific wear rate (SWR) and coefficient of friction (COF). RSM proposes a quadratic model to represent the mathematical relationship between input parameters for evaluating SWR and COF. The desirability function approach is employed to optimize input parameters to minimize both SWR and COF. The optimized values of SWR and COF are 6.87 × 10−4 mm3/N.m and 0.30 under a 27.52 N load, 2.86 Hz oscillation frequency, and 1100˚C annealing temperature. Surface topography analysis of the worn surface was evaluated using SEM and a profilometer to understand the wear mechanism and surface characteristics.

Synergy of Oxygen Octahedra Distortion and Polar Nanodomains Induced Emergent Electrocaloric Effect in NaNbO3-Based Ceramics.

High-performance electrocaloric materials are essential for the development of solid-state cooling technologies; however, the contradiction of the electrocaloric effect (ECE) and temperature span in ferroelectrics frustrates practical applications. In this work, through modulating oxygen octahedra distortion and short-range polar nanodomains with moderate coupling strength, an EC value of ΔT ∼ 0.30 K with an ultrawide temperature span of 85 K is obtained in the x = 0.04 composition [(0.88 - x)NaNbO3-0.12BaTiO3-xLiSbO3 (x = 0-0.06)]. The LiSbO3 dopant induces a P4bm-to-R3cH phase transition and intensifies the oxygen octahedra distortion degree, accompanied by the ferroelectric domain smashing into polar nanodomains. Also, LiSbO3 addition enhances the relaxation degree with a downshift of Tfd (ferroelectric-to-diffuse phase transition temperature) and TJ (temperature of the maximal current density value), and Tfd is shifted to near room temperature with an absence of TJ in x = 0.04. Local energy barriers induced by oxygen octahedra distortion inhibit the phase transition in conjunction with activation of short-range polar order switching under thermal stimuli, which is the underlying mechanism for an excellent EC performance for x = 0.04. This work not only clarifies that ferroelectrics with oxygen octahedra distortion and short-range polar order are expected to achieve remarkable EC performances but also provides a design strategy to seek emergent EC behaviors in complex oxygen-octahedra-distortion materials.

A self-reinforced luminescence signal amplification strategy to construct electrochemiluminescence immunosensor for carcinoembryonic antigen sensing

Carcinoembryonic antigen (CEA) is a disease biomarker that reflects the presence of various cancers and tumors in the human body. Sensitive detection of CEA concentration in the blood is beneficial for the clinical diagnosis and treatment evaluation of cancer. Electrochemiluminescence (ECL) sensors used for disease pre-screening are usually subjected to various complex chemical modifications for real-time analysis and detection of CEA concentration in the blood. The ECL behavior of a novel self-reinforced ECL complexes Zn-MOF-Ru-TEA coreacting at the anode is reported in this paper. The self-reinforced ECL complexes Zn-MOF-Ru-TEA are synthesized using one-pot method. Compared with the redox reaction of TEA in the PBS buffer, the energy and charge transport distance provided by Ru(bpy)32+ and TEA molecules in the pore size of Zn-MOF are greatly shortened, so the ECL efficiency of Ru(bpy)32+ is effectively improved. The Cu+/Cu2+ ion pair cycle in the signal label CuNiOS/Au NPs can react with TEA enriched in Zn-MOF-Ru-TEA to produce more reactive radicals, which realizes the amplification strategy of the ECL signal caused by Cu+-triggered probes. Under optimal conditions, the linear range of CEA detection is 10−5 ng·mL−1 to 80 ng·mL−1, and the detection limit is 3.43 fg·mL−1. This is the first time that a Ru(bpy)32+/TEA self-reinforced ECL system has been proposed for CEA detection, which has the advantages of low limit of detection and high sensitivity and offers the potential for the application of sensitive determination of biomarkers.

Interplay of PROTAC Complex Dynamics for Undruggable Targets: Insights into Ternary Complex Behavior and Linker Design.

Protein degraders, such as bifunctional proteolysis-targeting chimeras (PROTACs), selectively eliminate target proteins by leveraging the natural protein degradation machinery. PROTACs bridge the target protein with an E3 ligase, which induces ubiquitination and degradation. Investigating ternary complex structures elucidates the molecular mechanisms of their formation and degradation. This study examines the binding dynamics of E3 ligases (VHL, CRBN, and cIAP) with proteins of interest, focusing on dynamics, cooperativity, selectivity, linker length, and PROTAC conformations. The influence of interface residues and linker lengths on specific conformations for target proteins and E3 ligases is highlighted. Utilizing molecular dynamics and steered molecular dynamics simulations, the study provides comprehensive parameters on the behavior and stability of diverse ternary complexes. These insights are crucial for designing PROTACs targeting disease-causing proteins and advancing the development of degradable ternary complexes for therapeutic applications.

A comparison of foot and ankle biomechanics during running drills and distance running

ABSTRACT The aim of this study was to compare the foot-ankle joint mechanics of running drills and running. Seventeen long-distance runners performed five popular running drills (A-skip, B-skip, Bounding, Heel flicks, Straight leg running) and a run at 3.88 m/s. Kinematics, kinetics and power values were calculated for the ankle, midtarsal (MT) and metatarsophalangeal (MP) joints. Electromyographic activity was recorded for the soleus, gastrocnemius medialis, lateralis and abductor hallucis muscle. The A-skip, the B-skip and the Heel flicks induced a smaller ankle (p < 0.001, ŋ2 = 0.41), MT (p < 0.001, ŋ2 = 0.43) and MP (p < 0.001, ŋ2 = 0.47) dorsiflexion peak than running. No difference was found between the running drills and running for ankle, MT and MP moment. The Bounding induces a higher positive ankle power than running (diff: 5.5 ± 7.5 J/kg, p = 0.014, d = 1.05). The A-skip (diff: 2.8 ± 2.9 J/kg, p < 0.001, d = 1.5) and the B-skip (diff: 2.7 ± 2.1 J/kg, p < 0.001, d = 1.4) induce a smaller MT positive power than running. This study offers an analysis of the mechanical behaviour of the foot-ankle complex to help track and field coaches select their running drills in an evidence-based manner.

Benzyloxychalcone Hybrids as Prospective Acetylcholinesterase Inhibitors against Alzheimer's Disease: Rational Design, Synthesis, In Silico ADMET Prediction, QSAR, Molecular Docking, DFT, and Molecular Dynamic Simulation Studies.

Acetylcholinesterase inhibitors (AChEIs) are crucial therapeutic targets for both the early and severe stages of Alzheimer's disease (AD). Chalcones and their chromone-based derivatives are well-known building blocks with anti-Alzheimer properties. This study synthesized 4-benzyloxychalcone derivatives and characterized their structures using IR, 1H NMR, 13C NMR, and HRMS. Additionally, the synthesized 4-benzyloxychalcone derivatives were tested for anti-acetylcholinesterase (AChE) activity. The synthesized compounds outperformed galantamine, which is used as a positive control against acetylcholinesterase. Utilizing an acetylcholinesterase (AChE) receptor (PDB ID: 4EY7)-chalcone derivative (12a-c), a molecular docking investigation was performed on the synthesized compounds. The goal was to predict the binding sites and energies of the derivatives with respect to the receptor amino acids. The dynamic behavior of the ligand-receptor complex resulting from the interaction of the best docking compounds 12a and 12c with the acetylcholinesterase receptor was used to analyze the stability via MD simulation. MM/GBSA and MM/PBSA were used to calculate free binding energies using snapshots from system trajectories. Advanced computational approaches incorporating long-range corrections were utilized to calculate the molecular characteristics of chalcone derivatives 12a-c at the DFT/wB97XD/6-311++G(d,p) level. We used the molecular electrostatic surface potential (MESP) with high-quality data and visualization to find the most active site in these molecules. Reactivity descriptors, including the condensed Fukui function, chemical hardness (η), dual descriptors, chemical potential (μ), and electrophilicity (ω), were calculated for the chalcone derivatives.

Earthquake Performance Analysis of a Masonry School Building's Retrofitted State by the Equivalent Frame Method

Nonlinear analyses of masonry structures are frequently used in both engineering practice and academic studies. Due to the dominant nonlinear behaviour of masonry structures, complex and extensive finite element models are required to obtain accurate analysis results. While masonry walls are usually modelled using fine-meshed shells or solid elements in such structures, high computing power in modelling, analyzing, and post-processing results is necessary for the analyses of large structures. In recent years, the equivalent frame method, as a solution to this problem has been developed and presented in the literature. In this study, the equivalent frame method is used in a masonry structure modelling, and the axial force-bending relationship is represented by force-based fiber elements. The multi-linear load-deformation relationship reflects the shear behaviour of the walls. Within the scope of the study, an existing masonry school building is modelled using the equivalent frame elements with OpenSees software. Seismic performance analyses are done considering the existing and retrofitted states of the structure, and the results are discussed in a comparative manner.

The influence of microstructure on the oxidation behavior of a TaTiCr refractory complex concentrated alloy

This work explores the effect of microstructure on the oxidation behavior of an equiatomic TaTiCr RCCA after 24 h of exposure at 800°C, 1000°C, 1200°C, and 1400°C. Two microstructural conditions, both containing a bcc matrix with C15 Laves precipitates, with one condition having coarser precipitates (∼10.9 µm diameter) and one condition having finer precipitates (∼2.9 µm diameter) were studied. At all oxidation temperatures except 800°C, the finer-scale (TaTiCr-F) condition experienced more rapid oxidation kinetics, higher mass gains, and thicker oxide scales and internal reaction zones. However, at 800°C, the microstructure containing coarser precipitates (TaTiCr-C) formed a thicker oxide scale. Continuous, protective Cr2O3 layers were only observed in the coarse precipitate condition and correlations between Cr2O3 layer thickness, subsequent formation of complex refractory oxides, and the initial Laves precipitate size are described. It is proposed that the formation of continuous Cr2O3 is highly dependent on the size and distribution of the Cr-rich Laves phase and only mildly dependent on phase fraction. Oxidation mechanisms for each condition are discussed relative to the initial microstructures, observed oxide species, and related alloy systems.

Exploring Plant-Based Compounds as Alternatives for Targeting Enterococcus faecalis in Endodontic Therapy: A Molecular Docking Approach.

Endodontic infections pose significant challenges in dental practice due to their persistence and potential complications. Among the causative agents, Enterococcus faecalis stands out for its ability to form biofilms and develop resistance to conventional antibiotics, leading to treatment failures and recurrent infections. The urgent need for alternative treatments arises from the growing concern over antibiotic resistance and the limitations of current therapeutic options in combating E. faecalis-associated endodontic infections. Plant-based natural compounds offer a promising avenue for exploration, given their diverse bioactive properties and potential as sources of novel antimicrobial agents. In this study, molecular docking and dynamics simulations are employed to explore the interactions between SrtA, a key enzyme in E. faecalis, and plant-based natural compounds. Analysis of phytocompounds through molecular docking unveiled several candidates with binding energies surpassing that of the control drug, ampicillin, with pinocembrin emerging as the lead compound due to its strong interactions with key residues of SrtA. Comparative analysis with ampicillin underscored varying degrees of structural similarity among the study compounds. Molecular dynamics simulations provided deeper insights into the dynamic behavior and stability of protein-ligand complexes, with pinocembrin demonstrating minimal conformational changes and effective stabilization of the N-terminal region. Free energy landscape analysis supported pinocembrin's stabilizing effects, further corroborated by hydrogen bond analysis. Additionally, physicochemical properties analysis highlighted the drug-likeness of pinocembrin and glabridin. Overall, this study elucidates the potential anti-bacterial properties of selected phytocompounds against E. faecalis infections, with pinocembrin emerging as a promising lead compound for further drug development efforts, offering new avenues for combating bacterial infections and advancing therapeutic interventions in endodontic practice.