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In the search for new metabolite inhibitors, a natural product activity and species source (NPASS) database was virtually screened using AutoDock software to identify potential NRP1 inhibitors. NPASS compounds complexed with NRP1 were subjected to molecular dynamics (MD) simulations. Furthermore, NPASS-NRP1 binding affinities were calculated using the MM-GBSA approach. Based on calculated binding energies, kamolonol (NPC146388) demonstrated lower NRP1 binding affinity than the co-crystallized HRG/Arg-1 ligand with binding energy (ΔGbinding) values of –34.5 and –32.0 kcal/mol, respectively. Structural and energetic analysis showed high stability for kamolonol and HRG/Arg-1 with NRP1 over the 200 ns MD simulations. The studied physicochemical properties of kamolonol and HRG/Arg-1 revealed that these compounds obey Lipinski's rule of five. ADMET characteristics of kamolonol and HRG/Arg-1 were predicted, and kamolonol showed better ADMET properties compared to HRG/Arg-1. Based on these results, kamolonol is a promising NRP1 inhibitor worthy of further experimental assays as anti-carcinoma remediation. [ABSTRACT FROM AUTHOR]

Interleukin-8 (IL-8) is a chemokine, a type of signaling molecule that has a role in immunological responses and inflammation. In recent years, IL-8 is additionally related to cancer growth and recurrence. Breast cancer growth, progression, and metastatic development are all linked to IL-8. Breast cancer cells are known to develop faster when IL-8 stimulates their proliferation and survival. It can also cause angiogenesis, or the creation of new blood vessels, which is necessary for tumor nutrition and growth. IL-8 and curcumin have been subjects of interest in drug design, particularly in the context of inflammation-related disorders and cancer. This study aims to give an overview of the role of IL-8. Inhibitor-based treatment approaches were being used to target IL-8 with curcumin. Molecular docking method was employed to find a potential interaction to supress competitive inhibition of IL-8 with curcumin. PASS analysis and ADMET characteristics were also being carried out. In the end, IL-8 complexed with curcumin is chosen for MD simulations. Overall, our results showed that during the simulation, the complex stayed comparatively stable. It is also possible to investigate curcumin further as a possible treatment option. The combined results imply that IL-8 and their genetic alterations can be studied in precision cancer therapeutic treatments, utilizing target-driven therapy and early diagnosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 quantum dots (QDs) modified asphalt has been proposed as an innovative cool pavement technology. • Electronic and optical characteristics of TiO 2 QDs are investigated based on quantum mechanics calculations. • Modification mechanism and properties of TiO 2 QDs modified asphalt are evaluated based on molecular dynamics simulations. • Impacts of quantum sizes and concentrations on properties of TiO 2 QDs modified asphalt are analyzed. With exceptional solar reflectivity and fluorescent characteristics, TiO 2 quantum dots (QDs) modified asphalt has been proposed as an innovative cool pavement technology. However, interaction mechanism and thermodynamic properties of TiO 2 QDs modified asphalt at microscale have not been well understood. In this study, electronic and optical properties of TiO 2 QDs with varied sizes were investigated based on quantum mechanics (QM) calculations. Moreover, molecular dynamics (MD) simulations were implemented to evaluate mechanical moduli and intermolecular dynamics of TiO 2 QDs modified asphalt with different quantum sizes and concentrations. The results from QM calculations unveil that as size of TiO 2 QDs rises from 6 Å to 12 Å, energy gap and binding energy of TiO 2 QDs decreases by 0.928 eV and 526.38 eV, respectively while density of state (DOS) and absorption coefficient of TiO 2 QDs increases. Besides, the results from MD simulations reveal that quantum size imposes significant impact on mechanical moduli of modified asphalt while concentration of TiO 2 QDs brings notable influence on interaction between quantum dots and asphalt. Specifically, as concentration of QDs rises from 10 % to 30 %, cohesive energy density (CED) and solubility parameter (SP) of modified asphalt is improved by up to 457 % and 136 %, respectively. With increasing quantum size, bulk modulus, shear modulus, and Young's modulus of modified asphalt is enhanced by up to 372 %, 206 % and 24 %, respectively. The outcomes of this study provide insights into formula and application of advanced asphalt pavement with TiO 2 QDs. [ABSTRACT FROM AUTHOR]

Background: In seek of potent and non-toxic iminoguanidine derivatives formerly assessed as active Pseudomonas aeruginosa inhibitors, a combined mathematical approach of quantitative structure-activity relationship (QSAR), homology modeling, docking simulation, ADMET, and molecular dynamics simulations were executed on iminoguanidine derivatives. Results: The QSAR method was employed to statistically analyze the structure-activity relationships (SAR) and had conceded good statistical significance for eminent predictive model; (GA-MLR: Q2LOO = 0.8027; R2 = 0.8735; R2ext = 0.7536). Thorough scrutiny of the predictive models disclosed that the Centered Broto-Moreau autocorrelation - lag 1/weighted by I-state and 3D topological distance-based autocorrelation—lag 9/weighted by I-state oversee the biological activity and rendered much useful information to realize the properties required to develop new potent Pseudomonas aeruginosa inhibitors. The next mathematical model work accomplished here emphasizes finding a potential drug that could aid in curing Pseudomonas aeruginosa and SARS-CoV-2 as the drug targets Pseudomonas aeruginosa. This involves homology modeling of RNA polymerase-binding transcription factor DksA and COVID-19 main protease receptors, docking simulations, and pharmacokinetic screening studies of hits compounds against the receptor to identify potential inhibitors that can serve to regulate the modeled enzymes. The modeled protein exhibits the most favorable regions more than 90% with a minimum disallowed region less than 5% and is simulated under a hydrophilic environment. The docking simulations of all the series to the binding pocket of the built protein model were done to demonstrate their binding style and to recognize critical interacting residues inside the binding site. Their binding constancy for the modeled receptors has been assessed through RMSD, RMSF, and SASA analysis from 1-ns molecular dynamics simulations (MDS) run. Conclusion: Our acknowledged drugs could be a proficient cure for SARS-CoV-2 and Pseudomonas aeruginosa drug discovery, having said that extra testing (in vitro and in vivo) is essential to explain their latent as novel drugs and manner of action. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) based alloys are promising candidates for many applications, but their untreated surfaces usually have low strength and hardness. In this study, a single point diamond turning (SPDT) technique was applied to refine the grain size and improve the mechanical properties of the surface layers of Mg-Li alloys. By refining grains in the topmost layer to the nanometer scale (∼ 60 nm), the surface hardness was found to be enhanced by approximately 60%. The atomic plastic deformation process during the SPDT was then studied by the real-time atomistic molecular dynamics (MD) simulations. A series of MD simulations with different combinations of parameters, including rake angle, cutting speed and cutting depth, were conducted to understand their influences on the microstructural evolution and associated plastic deformation mechanisms on the surface layer of the workpieces. The MD simulation results suggest that using increased rake angle, cutting speed and cutting depth can help to achieve better grain refinement. These simulation results, which provide atomic-level details of the deformation mechanism, can assist the parameter design for the SPDT techniques to achieve the high-performance heterogeneous nanostructured materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The in vitro antimicrobial and antioxidant activities of spiropyrazoline oxindole congeners were carried out. • Some spiro-compounds represent interesting antimicrobial and antioxidant activities. • The in vitro activities were supported by in-silico studies using DFT method, Molecular Docking, Molecular Dynamics Simulation and POM analysis. • A good correlation between the experimental results and in-silico studies was observed. • POM analyses show that all compounds exhibited good bioavailability, pharmacokinetic, and no toxicity profiles. The search for novel powerful antimicrobial and antioxidant agents is considered a dynamic field in medicinal chemistry. In this context, a series of spiropyrazoline indolin-3-one congeners were assessed for their in vitro bioactivities, and in-silico studies were conducted to support the experimental results. The antimicrobial screening of the spiropyrazoline oxindole congeners against the selected microbe strains (Staphylococcus aureus (CECT 976), Bacillus subtilis (DSM 6633), Escherichia coli (K12), and Candida albicans (ATCC 10231)) exhibited moderate to excellent, compared to control standard antibiotics (Ampicillin, streptomycin and fluconazole). This activity was observed to be tightly dependent upon the nature of the substituents carried by the aromatic rings. Moreover, the tested compounds showed variable dose-dependent antioxidant activity. Notably, congeners 2c , 2d and 2e exhibited a remarkable antioxidant activity, due to the positive impact of the electron-donating groups (CH 3 and OCH 3) on the antioxidant activity. Density functional theory (DFT) simulations were executed on the target molecules to better understand their structural and electronic properties, as well as to explain the results obtained from the antioxidant activity. The molecular docking studies showed that the studied congeners have good binding affinities and interactions with the target proteins (catalase compound II and CYP51). Moreover, the 100 ns molecular dynamics (MD) simulation analysis was conducted to follow the behavior of the complexes formed between ligand 2e and the target proteins (2CAG and 5V5Z) under in-silico physiological conditions to explore and evaluate its stability over time. MD simulation indicated a stable conformation and binding patterns in a stimulating environment of the congeners (2CAG-2e and 5V5Z-2e). The results of Petra/Osiris/Molinspiration (POM) analyses suggested that all the spiranic cycloadducts have good oral bioavailability and pharmacokinetics without any evidence of observed toxicity. Taken together, our findings provide valuable experimental and theoretical information that will be helpful for designing novel spiranic molecules with potential pharmacological applications. [ABSTRACT FROM AUTHOR]

The novel coronavirus pandemic has spread over in 213 countries as of July 2020. Approximately 12 million people have been infected so far according to the reports from World Health Organization (WHO). Preventive measures are being taken globally to avoid the rapid spread of virus. In the current study, an in silico approach is carried out as a means of inhibiting the spike protein of the novel coronavirus by flavonoids from natural sources that possess both antiviral and anti-inflammatory properties. The methodology is focused on molecular docking of 10 flavonoid compounds that are docked with the spike protein of SARS-CoV-2, to determine the highest binding affinity at the binding site. Molecular dynamics simulation was carried out with the flavonoid-protein complex showing the highest binding affinity and highest interactions. The flavonoid naringin showed the least binding energy of −9.8 Kcal/mol with the spike protein which was compared with the standard drug, dexamethasone which is being repurposed to treat critically ill patients. MD simulation was carried out on naringin-spike protein complex for their conformational stability in the active site of the novel coronavirus spike protein. The RMSD of the complex appeared to be more stable when compared to that of the protein from 0.2 nm to 0.4 nm. With the aid of this in silico approach further in vitro studies can be carried out on these flavonoids against the novel coronavirus as a means of viral protein inhibitors. [ABSTRACT FROM AUTHOR]

• A protocol for encapsulating of sarin into the cavity of β-Cyclodextrin was developed. • The interactions of host' components with phosphorus and fluorine of sarin can help to hydrolysis and thus detoxify sarin. • The complexation was energetically driven by the non-bond interactions between the sarin molecule and β-Cyclodextrin. β-cyclodextrins (β-CDs) are able to trap and hydrolyze certain nerve agents such as sarin. Herein, we studied the host-guest interactions of sarin with β-CD by performing quantum mechanical (QM) calculations and molecular dynamics (MD) simulations. The calculated results indicated that the stable inclusion complex can be formed in both vacuum and water. Also, dynamic and structural parameters revealed that the intramolecular hydrogen bonds and van der Waals interactions effectively help to maintain the stability of the sarin structure within the β-CD cavity. More importantly, it was shown that how the interactions of host' components with phosphorus and fluorine of sarin can help to hydrolysis and thus detoxify sarin. [ABSTRACT FROM AUTHOR]

VEGFR-2 is a significant target in cancer treatment, inhibiting angiogenesis and impeding tumor growth. Utilizing the essential pharmacophoric structural properties, a new semi-synthetic theobromine analogue (T-1-MBHEPA) was designed as VEGFR-2 inhibitor. Firstly, T-1-MBHEPA 's stability and reactivity were indicated through several DFT computations. Additionally, molecular docking, MD simulations, MM-GPSA, PLIP, and essential dynamics (ED) experiments suggested T-1-MBHEPA 's strong binding capabilities to VEGFR-2. Its computational ADMET profiles were also studied before the semi-synthesis and indicated a good degree of drug-likeness. T-1-MBHEPA was then semi-synthesized to evaluate the design and the in silico findings. It was found that, T-1-MBHEPA inhibited VEGFR-2 with an IC 50 value of 0.121 ± 0.051 µM, as compared to sorafenib which had an IC 50 value of 0.056 µM. Similarly, T-1-MBHEPA inhibited the proliferation of HepG2 and MCF7 cell lines with IC 50 values of 4.61 and 4.85 µg/mL respectively - comparing sorafenib's IC 50 values which were 2.24 µg/mL and 3.17 µg/mL respectively. Interestingly, T-1-MBHEPA revealed a noteworthy IC 50 value of 80.0 µM against the normal cell lines exhibiting exceptionally high selectivity indexes (SI) of 17.4 and 16. 5 against the examined cell lines, respectively. T-1-MBHEPA increased the percentage of apoptotic MCF7 cells in early and late stages, respectively, from 0.71 % to 7.22 % and from 0.13 % to 2.72 %, while the necrosis percentage was increased to 11.41 %, in comparison to 2.22 % in control cells. Furthermore, T-1-MBHEPA reduced the production of pro-inflammatory cytokines TNF-α and IL-2 in the treated MCF7 cells by 33 % and 58 %, respectively indicating an additional anti-angiogenic mechanism. Also, T-1-MBHEPA decreased significantly the potentialities of MCF7 cells to heal and migrate from 65.9 % to 7.4 %. Finally, T-1-MBHEPA 's oral treatment didn't show toxicity on the liver function (ALT and AST) and the kidney function (creatinine and urea) levels of mice. [ABSTRACT FROM AUTHOR]

[Display omitted] • The extraction of PPs with IL aqueous solution was monitored by MD simulation. • The role of the cationic and anionic parts on the PPs removal was evaluated. • The solvation pattern and interaction energy between PPs and solution components were analyzed. • The contributions of each of the non-bonded interactions were determined. In this study, the solvation behavior of phenolic pollutants (PPs) in 1-octyl-3-methylimidazolium tetrafluoroborate ([C 8 MIM][BF 4 ]) ionic liquid (IL) aqueous solutions was simulated using molecular dynamics (MD) simulations. The study found that the cationic part of IL was the most interactive and played the most important role in the extraction of PPs. It also demonstrated that stronger hydrophobic interactions between PPs and the cationic portion resulted in higher extraction efficiency, with the exception of resorcinol, whose stronger hydrogen bonds (HBs) with water molecules reduced extraction efficiency. The study discovered that van der Waals forces governed interaction energies (IEs) between PPs and ILs, while HBs played a minor role. Since the cationic part plays a major role in the extraction process of PPs, the efficiency of the extraction process can be improved by making structural changes to this part. [ABSTRACT FROM AUTHOR]

Abstract The binding of metal ions with humic acid (HA) plays an important role in the aggregation of HA and the migration of metal ions in the environments. The effects of common cations (Na+, Mg2+, Ca2+ and Al3+) and heavy metal ions (Ag+, Cd2+, Cu2+, Cr3+ and Eu3+) on the aggregation of HA were investigated systematically by aggregation kinetics, spectroscopic techniques and molecular dynamic (MD) simulations. The critical coagulation concentration (CCC) of mono-, di- and trivalent cations could be predicted by the Schulze-Hardy rule. The aggregation of HA in the presence of Na+ and Ag+ was mainly due to the reduction of repulsive force and the hydrogen bonds between HA molecules. While the complexation of di- and trivalent cations with carboxylic/phenolic groups, or the cation-π interactions enhanced the intra- or inter-molecular bridges in HA and then contributed greatly to the aggregation of HA. Heavy metal ions could easily pass through the electric double-layer of HA compared with common cations. MD simulations further signified the strong aggregation ability of HA molecules in solutions containing high valence metal ions. These findings are important for understanding not only how the influence of metal ions on the aggregation of HA, but also the conditions which ions more efficient for aggregation. Graphical abstract Image 1 Highlights • Hydrogen bonding interactions between HA molecules play important roles in the aggregation. • Multivalent cations affect the aggregation by forming intra- or inter-molecular bridges between HA molecules. • Heavy metal ions are more aggressively in HA aggregation than common cations. Different types of metal ions were considered to investigate the aggregation behaviors of HA colloids, which help us to better understand HA behaviors in the environment. [ABSTRACT FROM AUTHOR]

To explore the underlying molecule mechanism of herbal medicine in preventing ventricular remodeling (VR), we take a herbal formula that is clinically effective for preventing VR as an example, which composed of Pachyma hoelen Rumph, Atractylodes macrocephala Koidz., Cassia Twig and Licorice. Due to multi-components and multi-targets in herbal medicine, it is extremely difficult to systematically explain its mechanisms of action. An innovative systematic investigation framework which combines with pharmacokinetic screening, target fishing, network pharmacology, DeepDDI algorithm, computational chemistry, molecular thermodynamics, in vivo and in vitro experiments was performed for deciphering the underlying molecular mechanisms of herbal medicine for treating VR. ADME screening and SysDT algorithm determined 75 potentially active compounds and 109 corresponding targets. Then, systematic analysis of networks reveals the crucial active ingredients and key targets in herbal medicine. Additionally, transcriptomic analysis identifies 33 key regulators during VR progression. Moreover, PPI network and biological function enrichment present four crucial signaling pathways, i.e. NF-κB and TNF, PI3K-AKT and C-type lectin receptor signaling pathways involved in VR. Besides, both molecular experiments at animal and cell levels reveal the beneficial effect of herbal medicine on preventing VR. Finally, MD simulations and binding free energy validate the reliability of drug-target interactions. Our novelty is to build a systematic strategy which combines various theoretical methods combined with experimental approaches. This strategy provides a deep understanding for the study of molecular mechanisms of herbal medicine on treating diseases from systematic level, and offers a new idea for modern medicine to explore drug interventions for complex diseases as well. [ABSTRACT FROM AUTHOR]

Objective To evaluate the anti-hyperglycemic potential of sinigrin using in vitro , in silico and in vivo streptozotocin (STZ) induced hyperglycemic zebrafish model. Methods The in vitro enzyme inhibition assay was carried out to determine the IC 50 value against α-glucosidase and α-amylase, in silico molecular docking was performed against both enzymes with PyRx tool and simulations were performed using GROMACS tool. Hyperglycemia was induced in zebrafishes using three intraperitoneal injections on alternating days for 1 week at 350 mg/kg of STZ. Hyperglycemic fishes were treated intraperitoneally with 50, 100 and 150 mg of sinigrin/kg of body weight for 24 h and glucose levels were measured. Results The sinigrin showed very strong inhibition against α-glucosidase and α-amylase with 0.248 and 0.001 24 μM while reference drug acarbose showed IC 50 value of 73.070 0 and 0.001 7 μM against α-glucosidase and α-amylase, respectively. Kinetic analysis revealed that sinigrin has the mixed type mode of inhibition against α-glucosidase. Molecular docking results revealed its strong binding affinity with α-glucosidase (−10.00 kcal/mol) and α-amylase (−8.10 kcal/mol). Simulations graphs confirmed its stability against both enzymes. Furthermore, in hyperglycemic zebrafishes most significant ( P < 0.001) reduction of glucose was occurred at 150 mg/kg, moderate significant reduction of glucose was observed at 100 mg/kg and no any significant reduction of glucose was measured at 50 mg/kg. Conclusions It can be evident from the present results that sinigrin has potent anti-hyperglycemic activity and it may prove to be effective treatment for the hyperglycemia. [ABSTRACT FROM AUTHOR]

Heterocyclic molecules are well-known drugs against various diseases including cancer. Many tyrosine kinase inhibitors including erlotinib, osimertinib, and sunitinib were developed and approved but caused adverse effects among treated patients. Which prevents them from being used as cancer therapeutics. In this study, we strategically developed heterocyclic thiazolo-[2,3-b]quinazolinone derivatives by an organic synthesis approach. These synthesized molecules were assessed against the epidermal growth factor receptor tyrosine kinase domain (EGFR-TKD) by in silico methods. Molecular docking simulations unravel derivative 17 showed better binding energy scores and followed Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties. The binding affinity displayed by synthetic congener and reference molecule erlotinib was found to be −8.26 ± 0.0033 kcal/mol and −7.54 ± 0.1411 kcal/mol with the kinase domain. Further, molecular dynamic simulations were conducted thrice to validate the molecular docking study and achieved significant results. Both synthetic derivative and reference molecule attained stability in the active site of the TKD. The synthetic congener and erlotinib showed free energy binding (ΔG bind) −102.975 ± 3.714 kJ/mol and −130.378 ± 0.355 kJ/mol computed by Molecular Mechanics Poison Boltzmann Surface Area (MM-PBSA) method. In addition, the motions of each sampled system including the Apo complex were determined by the principal component analysis and Gibbs energy landscape analysis. The in-vitro apoptosis study was performed using MCF-7 and H-1299 cancer cell lines. However, thiazolo-[2,3-]-quinazoline derivative 17 showed fair anti-proliferative activity against MCF-7 and H-1299. Further, the in-vivo study is necessary to determine the effectivity of the potent anti-proliferative, non-toxic molecule against TKD. [ABSTRACT FROM AUTHOR]

• Fluoroindazole (5-FIA) and chloroindazole (5-CIA) were selected as excellent corrosion inhibitors for copper in sulfuric acid media. • Both 5-FIA and 5-CIA were shown to be adsorbed on the surface of copper in parallel. • The corrosion inhibition capability of the 5-CIA was more prominent than that of the 5-FIA. • The results of experiments and theories coincided with each other. To reduce the degree of copper corrosion by the pickling solution, the introduction of organic inhibitors into the pickling solution is a reasonably effective measure.5-fluoro-1H-indazole (5-FIA) and 5‑chloro-1H-indazole (5-CIA) may act as exceptional inhibitors. Based on experimental and theoretical methods, the antiseptic ability of two indazole derivatives on copper in sulfuric acid was researched. The results of electrochemical experiments show that in the test solution containing 1 mM inhibitors, the corrosion inhibition efficiency (η) of 5-FIA and 5-CIA was 90.4% and 94.3%, respectively, indicating that 5-FIA and 5-CIA have outstanding corrosion inhibition capabilities and their antiseptic effects are in the order of 5-FIA < 5-CIA, which is also confirmed by observations of Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Furthermore, both 5-FIA and 5-CIA are mixed-type inhibitors and their adsorption behavior follows Langmuir isothermal adsorption model. The results of X-ray Photoelectron Spectroscopy (XPS), theoretical calculations, and molecular dynamics simulations further reveal the mechanism that 5-CIA has stronger adsorption capacity than 5-FIA. [Display omitted] [ABSTRACT FROM AUTHOR]

The deadliest recent pandemic outbreak of COVID-19 disease has severely damaged the socio-economic health of the people globally. Due to unavailability of any effective vaccine or treatment the human beings are still struggling to overcome the pandemic condition. In an attempt to discover anti-COVID molecule, we used in-silico approach and reported 160 natural polyphenols to identify the most promising druggable HITs that can further used for drug discovery process. The co-crystallized structure COVID protease enzyme (PDB id 6LU7) was used. HTVS, MD simulation, binding energy calculations and in-silico ADME calculation were done and analyzed. Depending upon the scores three compounds galangin, nalsudaldain and rhamnezine were identified and the docking score were found to be −7.704, −6.51, −4.212 respectively. These docked complexes were further subjected to MD simulation runs over a 100 ns time and the RMSD and RMSF values were determined. The RMSD values of three compounds were found to be 2.9 Å, 7.6 Å & 9.5 Å respectively and the lowest RMSF values suggested the steady stability of ligand–protein complexes. The binding free energies (ΔG) of compounds with protein were found to be −49.8, −56.45, −62.87 kJ/mole. Moreover, in-silico ADME calculations indicated the drug likeliness properties of these molecules. By considering all these in-silico results the identified HITs would be the most probable anti-COVID drug molecules that can be further taken in wet lab and can act as lead for development of newer inhibitor of COVID-19 main protease enzyme. [ABSTRACT FROM AUTHOR]

Extraction of methane from natural gas hydrates whilst storing CO 2 via gas replacement is a promising approach for reducing anthropogenic CO 2 emissions during energy generation. In this study, molecular dynamic simulations were performed to identify the influence of temperature, pressure, and the initial CO 2 concentration of sweep gas on the gas replacement characteristics. Simulations were performed under selected pressure and temperature conditions using five different initial CO 2 concentrations. The simulation results clearly portray the replacement phenomena where methane molecules are released into the free gas layer while CO 2 get enclathrated in hydrate structure. During gas replacement, minor structural changes in hydrate structure can also be observed, but they are quite insignificant as demonstrated through the alterations in Tetrahedrality order parameter. The variations of the number densities of gas and water molecules during gas replacement were used to quantify the methane recovery and CO 2 storage. Based on the numerical comparisons, the replacement process is found to be strongly dependant on the temperature, yielding a higher methane recovery at higher temperatures; however, the CO 2 storage capacity is found to be diminishing with increasing temperature. Having a higher initial CO 2 concentration in the sweep gas may facilitate greater penetration of CO 2 into the hydrate structure, eventually resulting in a higher methane recovery and improved CO 2 storage. • Hydrogen bonds in methane hydrates undergo minor adjustments during CO 2 replacement. • Methane recovery is higher at higher temperatures. • Low temperatures are more suitable for improved CO 2 storage. • Pressure has a minimal effect on methane recovery at a constant temperature. • High initial CO 2 concentrations yield high CO 2 penetration in methane hydrates. [ABSTRACT FROM AUTHOR]

The present study accounts for cholest-5-en-7-one (steroid) synthesis using selenium dioxide and silica as well as its identification using high-resolution mass spectrometry (HRMS), FT-IR, NMR, and elemental analysis. Density functional theory (DFT) calculations were used to optimize the steroid's geometry, which was then compared to single-crystal X-ray diffraction data, indicating that the computational and experimental results were in good agreement. UV–vis absorption titration, fluorescence spectral methods, circular dichroism (CD), and dynamic light scattering (DLS) were used to investigate the well-identified steroid's in vitro molecular interaction with human serum albumin (HSA). The results and binding parameter indicate that the steroid has significant binding affinity for HSA. Molecular docking was performed and found that the steroid can interact with the hydrophobic cavity of HSA through hydrogen and hydrophobic contacts. Molecular dynamics simulation was used to confirm the stability of the HSA-steroid complex. Combined quantum mechanics-molecular mechanics (QM-MM) methods were applied to know binding energy of system and individual components for atomic level interactions indicating a significant interaction between the steroid and the biomacromolecules. The findings presented here contribute to a better understanding of steroid pharmacodynamics. [ABSTRACT FROM AUTHOR]

• Decomposition of TFM is result in HF fragment, C O & O H bond dissociation reaction. • Temp. & pressure dependent rate constant for HF fragment was significantly higher. • MD simulation calculations revealed dynamic insights of the reaction. • Trajectory analysis suggested dominant role of 9th vib. mode for product formation. • The results reported in present work are in line with experimental finding. The unimolecular dissociation of trifluoromethanol (CF 3 OH) had been studied by static and dynamic calculations. The electronic structure calculations and molecular dynamic (MD) simulations were performed at the second order Moller-Plesset perturbation theory (MP2) theory. The kinetic behavior was investigated in the temperature range from 298 to 1400 K and pressure range between 10−9 to 104 kPa using Troe's formalism. In addition to this, Born-Oppenheimer molecular dynamic (BOMD) model was employed for exploring the dynamic insights of the reaction. Reaction trajectories were estimated by microcanonical normal mode sampling, wherein selected vibrational modes were pumped with additional energy of 95, 155, and 208 kcal mol−1. Our calculations suggest that, the unimolecular decomposition of CF 3 OH results in the generation of molecular HF with concomitant generation of CF 2 O via intramolecular reaction. The MD simulations suggest the critical role of vibrational modes for such intramolecular reaction. [ABSTRACT FROM AUTHOR]

• Aniline based polymer as effective corrosion inhibitor for N80 steel. • Electrochemical measurements using potentiodynamic polarization and EIS. • SECM was used to study the localized electrochemical behavior. • SEM was used to observe the surface morphologies. • DFT and molecular simulations supported the experimental results. The corrosion inhibition efficiency of aniline, formaldehyde and piperazine based polymer (ADPD) on N80 steel in 3.5% NaCl solution saturated with carbon dioxide was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, weight loss, scanning electrochemical microscopy (SECM), scanning electron microscopy (SEM) measurements, density functional theory (DFT) and molecular dynamics simulation (MD). The adsorption of polymer onto N80 steel surface followed Langmuir adsorption isotherm model. Potentiodynamic polarization study confirmed that inhibitor is mixed type with cathodic predominance. SECM study reveals the current values decreases with the increasing concentration of polymer. SEM study supports the smooth metal surface texture. DFT and MD calculations are in agreement with the experimental findings. [ABSTRACT FROM AUTHOR]