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Alkylated fluorene-based conjugated porous polymers (CPPs) were developed for electrochemical detection of nitroaromatics (NAs). Poly[(1, 3, 5-tris(9,9-dihexyl-9H-fluorene-2,7-diyl) benzene)] [PPHF] and poly[(1,3,5-tris(5-(9,9-dihexyl-9H-fluorene) thiophene-2-yl)benzene)] [PPTHF], two CPPs with modified morphologies, showed improved porosity and charge transfer to NAs. PPTHF, featuring a thiophene moiety, exhibited superior sensing capabilities for 1,2-dinitrobenzene (1,2-DNB). Computational analysis confirmed strong bindings. This work introduces a novel approach for real-time safety monitoring and effective electrochemical sensing of NAs. [ABSTRACT FROM AUTHOR]

As a clean energy source, coalbed methane (CBM) produces almost no exhaust gas after combustion, and its extraction and efficient utilization play a key role in supporting sustainable development. Therefore, molecular dynamics simulations were used to research the diffusion of CH4 in coal after injecting CO2/N2 in different sequences and to clarify the efficiency of CBM extraction under different injection sequences, so as to contribute to sustainable development. The results show that the adsorption amounts of CO2 and N2 in different injection sequences are obviously different. To narrow the gap between the two injection amounts, the injection pressure of N2 can be appropriately increased and that of CO2 can be reduced, or N2 can be injected preferentially instead of CO2. When CO2 is injected first, the interaction energy between CH4 and coal is stronger and increases slightly with displacement time as a whole. The interaction energy curve of the N2 injection decreases, and the displacement effect becomes worse and worse. From the diffusion and relative concentration distribution of CH4, it can be seen that the diffusion of CH4 molecules outside the grain cell is more obvious when N2 is injected first. In terms of the number of CH4 molecules diffusing outside the crystal cell, it is less when CO2 is injected first than when N2 is injected first. The average value of the velocity distribution of CH4 increases slightly when CO2 is injected first and decreases significantly when N2 is injected first, but the average value is overall higher for N2 injection first. From the difference in diffusion coefficients before and after the gas injection, it can be seen that the decrease in permeability due to the expansion of the coal matrix by CO2 is more obvious than the increase in permeability due to the contraction of the coal matrix by N2. [ABSTRACT FROM AUTHOR]

The stability of the SARS virus can be affected by various environmental factors, including temperature, humidity, and pressure. In the present research, the effect of initial pressure on the stability of the SARS virus in the presence of water/Ag nanofluid (NF) is investigated using molecular dynamics (MD) simulation. The results revealed that initial pressure effectively changes the atomic evolution of the virus-NF system. Numerically, the diffusion coefficient of modeled samples changes from 32.33 nm2/ns to 9.489 nm2/ns by initial pressure varies from 1 bar to 10 bar. This structural evolution caused interatomic distance and force between virus particle changes. Finally, interaction energy is changed by initial pressure variation, and this parameter varies between −0.44695 kcal/mol to −24.65127 kcal/mol in defined initial conditions. From MD outputs, it was concluded physical stability of the SARS virus in the presence of water/silver NF can be manipulated by initial pressure. So, the SARS virus destruction process with water/silver NF affected from the initial pressure ratio, appropriately. Future directions for this research project may involve exploring the influence of additional environmental factors and utilizing the gained knowledge to develop antiviral materials. This study establishes a foundation for further investigations into the interaction between environmental factors, NFs, and viral infections, with the potential to contribute to the development of effective strategies for combating viral infections and designing innovative antiviral solutions.

Polymers adsorb onto nanoparticles, NPs, by different mechanisms. Thus, they reduce coagulation, avoid undesired phase separation or clustering, and give rise to hybrid colloids. These find uses in many applications. In cases of noncovalent interactions, polymers adsorb onto nanoparticles, which protrude from their surface; the polymer in excess remains in the medium. In covalent mode, conversely, polymers form permanent links with functional groups facing outward from the NPs’ surface. Polymers in contact with the solvent minimize attractive interactions among the NPs. Many contributions stabilize such adducts: the NP–polymer, polymer–polymer, and polymer–solvent interaction modes are the most relevant. Changes in the degrees of freedom of surface-bound polymer portions control the stability of the adducts they form with NPs. Wrapped, free, and protruding polymer parts favor depletion and control the adducts’ properties if surface adsorption is undesired. The binding of surfactants onto NPs takes place too, but their stabilizing effect is much less effective than the one due to polymers. The underlying reason for this is that surfactants easily adsorb onto surfaces, but they desorb if the resulting adducts are not properly stabilized. Polymers interact with surfactants, both when the latter are in molecular or associated forms. The interactions occur between polymers and ionic surfactants or amphiphiles associated with vesicular entities. Hybrids obtained in these ways differ each from each other. The mechanisms governing hybrid formation are manifold and span from being purely electrostatic to other modes. The adducts that do form are quite diverse in their sizes, shapes, and features, and depend significantly on composition and mole ratios. Simple approaches clarify the interactions among different particle types that yield hybrids.

In comparison with conventional macro-systems, two-dimensional sheet-like materials such as aluminum carbide (C3Al) are considered as promising drug delivery systems (DDSs) because of their bioavailability and high adsorption. The surface of two-dimensional materials, which is capable of binding to the molecules of drugs with moderate binding energies, can further improve this adsorption and bioavailability. Hence, the possibility of using C3Al for the delivery of fluorouracil (5FU) is investigated for the first time within this research study. According to the adsorption energy analysis, there is a binding between the molecules of 5FU and C3Al with a moderate interaction energy, which is one of the requirements for a promising DDS. The adsorption energy of 5FU drug on the C3Al monolayer in different complexes is in the range of − 15.67 to − 26.79 kcal/mol, and there is a rise in the dipole moment (DM) of the surface after 5FU is adsorbed. This rise in the DM following the formation of the complex is conducive to improving solubility that is considered a prerequisite in biological systems for drug delivery. There is a reduction in the energy of the highest-occupied molecular orbital (HOMO) of the diene overlaps with the lowest-unoccupied molecular orbital (LUMO) gap of C3Al from 3.45 eV to 2.80 eV following the adsorption of 5FU. According to the results, C3Al seems to be a promising candidate for the delivery of 5FU. The current works provides useful insights into the experimental formulation of DDSs for 5FU based on C3Al. [ABSTRACT FROM AUTHOR]

Roseolumiflavin is a deep red microcrystalline derivative of isoalloxazine that exhibits a weak photophysical activity in the solid state. In aqueous as well as in acidic solution of formic or acetic acid, respectively, it tends to form solvates. Herein, we present a set of binary and ternary roseolumiflavin solvates including one hydrate and a solvate hydrate. The impact of the solvent on solvate formation along with an in-depth structural analysis was investigated. Calculations of the lattice energies provide insight into the phase stability of the evaluated systems showing an energetic benefit for all solvates with values up to −395.82 kJ/mol. The total interaction energies between molecules calculated via Crystal Explorer further identified cofacial π···π stacks to be the most strongly bonding fragments in the crystal lattices for all systems except the formic acid solvate, followed by remarkably weaker hydrogen-bonded arrangements. The energetic contributions of single intermolecular interactions within the fragments are evaluated by an atoms-in-molecules approach. It is shown that physicochemical properties, such as thermal stability, can be tuned depending on the incorporated solvent molecules despite a high decomposition temperature of the chromophore. [ABSTRACT FROM AUTHOR]

The new compound 4-hydroxy-1-[(4-nitrophenyl)sulfonyl]pyrrolidine-2-carboxyllic acid was obtained by the reaction of 4-hydroxyproline with 4-nitrobenzenesulfonyl chloride. The compound was characterized using single crystal X-ray diffraction studies. Spectroscopic methods including NMR, FTIR, ES-MS, and UV were employed for further structural analysis of the synthesized compound. The title compound was found to have crystallized in an orthorhombic crystal system with space group P212121. The S1-N1 bond length of 1.628 (2) Å was a strong indication of the formation of the title compound. The absence of characteristic downfield 1H NMR peak of pyrrolidine ring and the presence of S–N stretching vibration at 857.82 cm−1 on the FTIR are strong indications for the formation of the sulfonamide. The experimental study was complemented with computations at the B3LYP/6-311G + + (d,p) level of theory to gain more understanding of interactions in the compound at the molecular level. Noncovalent interaction, Hirsfeld surface analysis and interaction energy calculations were employed in the analysis of the supramolecular architecture of the compound. Predicted ADMET parameters, awarded suitable bioavailability credentials, while the molecular docking study indicated that the compound enchants promising inhibition prospects against dihydropteroate synthase, DNA topoisomerase, and SARS-CoV-2 spike. Herein we present the solid state structure, noncovalent interaction and spectroscopic analysis of a prospective bioactive compound 4-hydroxy-1-[(4-nitrophenyl)sulphonyl]pyrrolidine-2-carboxyllic acid. [ABSTRACT FROM AUTHOR]

The compound 2-(3-phenyl)-5-((m-toluloxy) methyl)-4H-1,2,4-triazole-4-yl) benzoic acid (PTMTBA) has been characterized using various analytical techniques such as NMR, FT-IR, and single crystal X-ray diffraction. The molecular structure reveals some fascinating features. The O1--H1...N4 and C--H...p intermolecular hydrogen bonding between molecules constitute a three-dimensional molecular network. The crystal structure has been optimized using both Hartree-Fock (HF) and Density functional theory (DFT) calculations. The molecular electrostatic potential (MEP) and frontier molecular orbitals (FMOs) of the molecule have been analyzed to gain insight into its physical and chemical properties. 3D Hirshfeld surfaces and allied 2D fingerprint plots have been analyzed for molecular interactions. The molecule docks very well with the target protein (PDB code: 3FFP), indicating it to be an effective inhibitor of carbonic anhydrase. [ABSTRACT FROM AUTHOR]

The analysis of crystal structures of SF5 - or SF4 -containing molecules revealed that these groups are often surrounded by hydrogen or other fluorine atoms. Even though fluorine prefers F⋅⋅⋅H over F⋅⋅⋅F contacts, the latter appeared to be important in many compounds. In a significant number of datasets, the closest F⋅⋅⋅F contacts are below 95 % of the van der Waals distance of two F atoms. Moreover, a number of repeating structural motifs formed by contacts between SF5 groups was identified, including different supramolecular dimers and infinite chains. Among SF4 -containing molecules, the study focused on SF4 Cl compounds, including the first solid-state structure analyses of these reactive species. Additionally, electrostatic potential surfaces of a series of Ph-SF5 derivatives were calculated, pointing out the substituent influence on the ability of F⋅⋅⋅X contact formation (X=F or other electronegative atom). Interaction energies were calculated for different dimeric arrangements of Ph-SF5 , which were extracted from experimental crystal structure determinations.

Shale oil in China is widely distributed and has enormous resource potential. The pores of shale are at the nanoscale, and traditional research methods encounter difficulty in accurately describing the fluid flow mechanism, which has become a bottleneck restricting the industrial development of shale oil in China. To clarify the distribution and migration laws of fluid microstructure in shale nanopores, we constructed a heterogeneous inorganic composite shale model and explored the fluid behavior in different regions of heterogeneous surfaces. The results revealed the adsorption capacity for alkanes in the quartz region was stronger than that in the illite region. When the aperture was small, solid–liquid interactions dominated; as the aperture increased, the bulk fluid achieved a more uniform and higher flow rate. Under conditions of small aperture/low temperature/low pressure gradient, the quartz region maintained a negative slip boundary. Illite was more hydrophilic than quartz; when the water content was low, water molecules formed a “liquid film” on the illite surface, and the oil flux percentages in the illite and quartz regions were 87% and 99%, respectively. At 50% water content, the adsorbed water in the illite region reached saturation, the quartz region remained unsaturated, and the difference in the oil flux percentage of the two regions decreased. At 70% water content, the adsorbed water in the two regions reached a fully saturated state, and a layered structure of “water–two-phase region–water” was formed in the heterogeneous nanopore. This study is of great significance for understanding the occurrence characteristics and flow mechanism of shale oil within inorganic nanopores.

We establish the Γ-convergence of some energy functionals describing nonlocal attractive interactions in bounded domains. The interaction potential solves an elliptic equation (local or nonlocal) in the bounded domain and the primary interest of our results is to identify the effects that the boundary conditions imposed on the potential have on the limiting functional. We consider general Robin boundary conditions, which include Dirichlet and Neumann conditions as particular cases. Depending on the order of the elliptic operator the limiting functional involves the usual perimeter or some fractional perimeter. We also consider the Γ-convergence of a related energy functional combining the usual perimeter functional and a nonlocal repulsive interaction energy. [ABSTRACT FROM AUTHOR]

Recombination events are very common and represent one of the primary drivers of RNA virus evolution. The XBF SARS-CoV-2 lineage is one of the most recently generated recombinants during the COVID-19 pandemic. It is a recombinant of BA.5.2.3 and BA.2.75.3, both descendants of lineages that caused many concerns (BA.5 and BA.2.75, respectively). Here, we performed a genomic survey focused on comparing the recombinant XBF with its parental lineages to provide a comprehensive assessment of the evolutionary potential, epidemiological trajectory, and potential risks. Genetic analyses indicated that although XBF initially showed the typical expansion depicted by a steep curve, causing several concerns, currently there is no indication of significant expansion potential or a contagion rate surpassing that of other currently active or previously prevalent lineages. BSP indicated that the peak has been reached around 19 October 2022 and then the genetic variability suffered slight oscillations until early 5 March 2023 when the population size reduced for the last time starting its last plateau that is still lasting. Structural analyses confirmed its reduced potential, also indicating that properties of NTDs and RBDs of XBF and its parental lineages present no significant difference. Of course, cautionary measures must still be taken and genome-based monitoring remains the best tool for detecting any important changes in viral genome composition. [ABSTRACT FROM AUTHOR]

We performed an investigation on urea interacting with hydroxyapatite (HA). The oxygen atoms on HA are either left alone or added with hydrogen to create hydroxyl to resemble the HA surface. Using B3LYP and 3 different basis sets, it was found that urea was able to interact positively with either hydroxyl or non-hydroxyl surface of HA. The Gaussian 09 and Multiwfn software were employed to conduct the calculations. The most favorable interaction has interaction energy of -1.36 eV, which was obtained with the 2 largest basis sets considered, on the pure hydroxyl surface. From the topology analysis on electron density and the non-covalent interaction analysis, it was found that the main attractions between urea and HA were due to the carbonyl oxygen and hydrogen of urea, and hydrogen, oxygen, and calcium on the HA surface. The bond length of newly bonded atoms ranges from 1.62 to 5.18 Å, whereas the energy gap has range between 0.46 to 1.14 eV. All the analysis performed in this study agreed with the results obtained in the formation of favorable interactions and complement previous experimental results that HA can bond with urea molecule. [ABSTRACT FROM AUTHOR]

Two monoclinic (P21/c; Z′ = 1) polymorphs, α (from methanol) and β (from ethanol, n-propanol and iso-propanol), of a bioactive pyrazolo[3,4-d]pyrimidine derivative have been isolated and characterised by X-ray crystallography as well as by a range of computational chemistry techniques. The different conformations observed for the molecules in the crystals are due to the dictates of molecular packing as revealed by geometry-optimisation calculations. The crucial difference in the molecular packing pertains to the formation of phenylamino-N–H···N(pyrazolyl) hydrogen bonding within supramolecular chains with either helical (α-form; 21-screw symmetry) or zigzag (β-form; glide symmetry). As a consequence, the molecular packing is quite distinct in the polymorphs. Lattice energy calculations indicate the β-form is more stable by 11 kJ/mol than the α-form. [ABSTRACT FROM AUTHOR]

In nanobiotechnology, organic molecule-containing two-dimensional nano-structured materials are considered crucial for developing horizontal bio-inorganic nano-devices for pharmaceutical applications. We present a complete review of the application of silicon carbide monolayer (SiCML) for smart drug delivery of hydroxyurea (HU) through density functional theory computations. Also, interacting host-guest complexes with different approaching orientations, the charge transport, and the interaction strength were scrutinized. It was found that the application of HU together with SiCML was significantly effective for bio-functionalization with −35.86 kcal/mol interaction energy. The charge transfer from HU to the SiCML was confirmed by Hirshfeld method. The findings of the current study provide useful insights into research on the application of functionalized nano-biomaterials for drug delivery, nano-medicine, and other related fields. [ABSTRACT FROM AUTHOR]

Abstract Fish swim bladders used to be considered as byproducts or waste in fishery; however, they are potential materials for biological medicine with abundant collagen. In this work, an efficient noncytotoxic decellularization process using sodium dodecyl sulfate (SDS) ternary system assisted with supercritical carbon dioxide (scCO2) as the green extraction fluid and ethanol (ET) as the cosolvent has been developed to harvest acellular fish swim bladders (AFSBs). The experimental results show that the tissue treated by SDS assisted with scCO2 and ethanol at 37 °C and 25 MPa can be decellularized thoroughly and maintains intact fibers and uniform pore distribution, which resulting in a tensile strength of 5.61 MPa and satisfactory biocompatibility. Meanwhile, the residual SDS content in scCO2/SDS/ET ternary system is 0.0122% which is significantly lower than it in scCO2/SDS system due to the enhanced mass transfer rate of SDS in tissues by scCO2 with ethanol. The synergy between SDS and ethanol can enhance the diffusion coefficient and the solubility of SDS in scCO2, which reduced the contact time between SDS and tissues. Meaningfully, the results obtained in this work can not only provide a novel strategy to produce acellular matrix with superior properties, but also offer a further understanding of the decellularization through scCO2 extraction processing with the synergy of suitable detergent/cosolvent. Graphical Abstract

Polymers stabilize the nanoparticles onto which they wrap, avoiding coagulation and undesired phase separation processes. Wrapping gives rise to hybrid colloids, and is useful in bio-intended applications. In non-covalent interaction modes, polymers physically adsorb onto the nanoparticles' surface, NPs, and some of their portions protrude outside. Both their non-interacting parts and the free polymers are in contact with the solvent, and/or are dispersed in it. Wrapping/protruding ratios were forecast with a simple statistical thermodynamic model, and the related energy calculated. The wrapping efficiency is controlled by different contributions, which stabilize polymer/NP adducts. The most relevant ones are ascribed to the NP-polymer, polymer–polymer, and polymer–solvent interaction modes; the related energies are quite different from each other. Changes in the degrees of freedom for surface-bound polymer portions control the stability of adducts they form with the NPs. The links between wrapped, free, and protruding states also account for depletion, and control the system's properties when the surface adsorption of hosts is undesired. Calculations based on the proposed approach were applied to PEO wrapping onto SiO2, silica, and nanoparticles. The interaction energy, W, and the changes in osmotic pressure associated with PEO binding onto the NPs have been evaluated according to the proposed model. [ABSTRACT FROM AUTHOR]

Modern Density Functional Theory models are now suitable for many molecular and condensed phase studies. The study of noncovalent interactions, a well‐known drawback, is no longer an insurmountable obstacle through design and empirical corrections. However, using empirical corrections as in the DFT‐D methods might not be an all‐in‐one solution. This work uses a simple system, X2‐H2O with X = Cl or Br, with two different interactions, halogen‐bonded (XB) and hydrogen‐halogen (HX), to investigate the capability of current density functional approximations (DFA) in predicting interaction energies with eight different exchange‐correlation functionals. SAPT(DFT) provides, for all the studied cases, better predictions than the widely used supermolecular approach. In addition, the components of the interaction energy suggest where some of the shortcomings originate in each DFA. The analysis of the functionals used confirms that PBE0 and ω‐B97X‐D have a physically correct behavior. Using SAPT(DFT) and PBE0, and ω‐B97X‐D, we obtained the interaction energy of Cl2 and Br2 inside different clathrate cages and satisfactorily compared with wavefunction results; hence, the lower and upper limits of this value are defined: Cl2@512, −5.3 ± 0.3 kcal/mol; Cl2@51262, −5.5 ± 0.1 kcal/mol; Br2@51262, −7.6 ± 1.0 kcal/mol; Br2@51263, −10.6 ± 1.0 kcal/mol; Br2@51264, −10.9 ± 0.8 kcal/mol. [ABSTRACT FROM AUTHOR]

Globally, the shift towards lignocellulosic biorefinery has opened avenues for valorizing lignin, a majorly accumulated recalcitrant by-product. A targeted lignin processing by ionic liquid-cosolvent mixtures can be an effective biomass conversion strategy. An understanding of lignin-ionic liquid dissolution can enable in designing a significant lignin processing technique to synthesis lignin-based renewable products. Here, we explored the molecular interaction during the dissolution of lignin containing five guaiacyl decamer chains in various (1-Ethyl-3-Methylimidazolium Acetate) EmimOAc-water mixtures using molecular dynamics simulation. The analysis showed that in only water, lignin formed a compact aggregate. Nevertheless, in 50%, 80%, and 100% EmimOAc-water, lignin underwent a segregated chain disentanglement with widespread dynamic motion. A detailed multifaceted analysis of Emim+, OAc− and water distribution on the polar and non-polar sites of lignin units was illustrated. An effective lignin dissolution was observed for 50% and 80% EmimOAc-water systems. The OAc− distribution was stronger around lignin's alkyl chains and alcoholic hydroxy groups. The Emim+ tails significantly impacted the benzene ring, whereas Emim+ heads were distributed around methoxy and hydroxy groups. Altogether, this study explores the lignin dissolution at atomistic level in EmimOAc-water mixtures; these understanding could serve as a cornerstone for engineering new ionic liquid-mediated lignin biorefinery. [Display omitted] [ABSTRACT FROM AUTHOR]

Solid dispersion of poorly soluble APIs is known to be a promising strategy to improve dissolution and oral bioavailability. To facilitate the development and commercialization of a successful solid dispersion formulation, understanding of intermolecular interactions between APIs and polymeric carriers is essential. In this work, first, we assessed the molecular interactions between various delayed-release APIs and polymeric excipients using molecular dynamics (MD) simulations, and then we formulated API solid dispersions using a hot melt extrusion (HME) technique. To assess the potential API–polymer pairs, three quantities were evaluated: (a) interaction energy between API and polymer [electrostatic (Ecoul), Lenard-Jones (ELJ), and total (Etotal)], (b) energy ratio (API–polymer/API–API), and (c) hydrogen bonding between API and polymer. The Etotal quantities corresponding to the best pairs: NPX-Eudragit L100, NaDLO–HPMC(P), DMF–HPMC(AS) and OPZ–HPMC(AS) were −143.38, −348.04, −110.42, and −269.43 kJ/mol, respectively. Using a HME experimental technique, few API–polymer pairs were successfully extruded. These extruded solid forms did not release APIs in a simulated gastric fluid (SGF) pH 1.2 environment but released them in a simulated intestinal fluid (SIF) pH 6.8 environment. The study demonstrates the compatibility between APIs and excipients, and finally suggests a potential polymeric excipient for each delayed-release API, which could facilitate the development of the solid dispersion of poorly soluble APIs for dissolution and bioavailability enhancement. [ABSTRACT FROM AUTHOR]

New hydrazone derivate, (1Z,2E)-2-(2-(1-(1,3-dimethyl-2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)ethyl)hydrazineylidene)-2-(p-tolyl)acetaldehyde oxime (H2L) was synthesized by 5-acetyl-1,3-dimethyl-barbituric acid and p-methyl isonitrosophenylhydrazine. Its molecular and crystal structures were determined by single crystal X-ray analysis. It belongs to triclinic system P-1 space group with a = 7.1722 (3) Å, b = 10.5362 (4) Å, c = 11.7675 (5) Å, α = 98.844 (4)°, β = 98.882 (4)°, γ = 104.330 (4)°, Z = 2 and V = 833.95 (6) Å3. In the molecular structure, the intramolecular N–H···O and N–H···N hydrogen bonds enclose S(6) ring motifs. In the crystal structure, the intermolecular C–H···O and O–H···O hydrogen bonds link the molecules into centrosymmetric dimers, enclosing R22(10) and R44(10) ring motifs, in which they may be effective in stabilization of the structure. The Hirshfeld surface analysis of crystal structure indicates that the most important contributions for crystal packing are from H...H (48.5%), H...O/O...H (23.7%) and H...C/C...H (9.7%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in crystal packing. Computational chemistry indicates that in the crystal, O–H···O and C–H···O hydrogen bond energies are 95.9 and 87.5 kJ mol−1. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that stabilization is dominated via the nearly equal strengths of the electrostatic and dispersion energy contributions. [ABSTRACT FROM AUTHOR]

In our present work, we applied Machine Learning approaches to predict potential energy profiles for rare gas dimers as well as for the H 2 molecule. We designed an Artificial Neural Network (ANN) model with one and two layers, with two to eight neurons in each layer, to predict potential energy values. We compared the ANN predicted energy values with the ab initio data and we found an excellent agreement between the actual and predicted values. The root mean squared deviation (RMSD) values for the test data are found to be 0.10, 0.22, 0.03 and 0.47 cm - 1 for He 2 , Ne 2 , Kr 2 and Ar 2 , respectively. Further, we observed that the ANN method is able to fit the potential energy profile for weak van der Waals dimers as well as covalently bound molecules. Application of machine learning approaches to predict the interaction energies for rare gas dimers is tested in this study. Our results show that Artifical Neural Network modeling is able to predict the energies for these van der Waals interactions. [ABSTRACT FROM AUTHOR]

Fibrinogen (FB) can trigger several biological reactions and is one of the critical proteins targeted during hemodialysis (HD). A better understanding of the thermal behavior of FB and its interactions with polymeric membranes during the HD process is needed in both normal and fever temperature conditions. This study calculated the thermal behavior of FB along with its interaction energy with polyarylethersulfone (PAES) clinical HD membranes using molecular dynamics (MD) approaches. The Dreiding force field was used for the MD simulations. The influence of temperature on the thermal conductivity (TC) and the interaction energy of the FB structure was assessed to understand the activation trends in fever conditions. Based on the MD simulation, the TC of FB at normal body temperature was 0.044 and 0.084 W/m·K according to equilibrium and non-equilibrium approaches, respectively. The elevation of temperature from normal to fever conditions increased the thermal conduction of FB to 0.577 and 0.114 W/m·K for equilibrium and non-equilibrium approaches, respectively. In addition, the elevation of patient blood temperature resulted in nearly 32 kcal/mol higher total interaction energy between FB and the PAES model. When end-stage renal disease (ESRD) patients have a HD session and experience fever and elevated temperature as a side effect, the interaction between FB and the membrane increases. More importantly, FB is exposed to more heat passage and accordingly more temperature-induced confirmation and activation compared to other human serum proteins such as albumin. [ABSTRACT FROM AUTHOR]

Fish swim bladders used to be considered as byproducts or waste in fishery; however, they are potential materials for biological medicine with abundant collagen. In this work, an efficient noncytotoxic decellularization process using sodium dodecyl sulfate (SDS) ternary system assisted with supercritical carbon dioxide (scCO2) as the green extraction fluid and ethanol (ET) as the cosolvent has been developed to harvest acellular fish swim bladders (AFSBs). The experimental results show that the tissue treated by SDS assisted with scCO2 and ethanol at 37 °C and 25 MPa can be decellularized thoroughly and maintains intact fibers and uniform pore distribution, which resulting in a tensile strength of 5.61 MPa and satisfactory biocompatibility. Meanwhile, the residual SDS content in scCO2/SDS/ET ternary system is 0.0122% which is significantly lower than it in scCO2/SDS system due to the enhanced mass transfer rate of SDS in tissues by scCO2 with ethanol. The synergy between SDS and ethanol can enhance the diffusion coefficient and the solubility of SDS in scCO2, which reduced the contact time between SDS and tissues. Meaningfully, the results obtained in this work can not only provide a novel strategy to produce acellular matrix with superior properties, but also offer a further understanding of the decellularization through scCO2 extraction processing with the synergy of suitable detergent/cosolvent. [ABSTRACT FROM AUTHOR]

Here, we investigate the performance of "Accurate NeurAl networK engINe for Molecular Energies" (ANI), trained on small organic compounds, on bulk systems including non‐covalent interactions and applicability to estimate solvation (hydration) free energies using the interaction between the ligand and explicit solvent (water) from single‐step MD simulations. The method is adopted from ANI using the Atomic Simulation Environment (ASE) and predicts the non‐covalent interaction energies at the accuracy of wb97x/6‐31G(d) level by a simple linear scaling for the conformations sampled by molecular dynamics (MD) simulations of ligand‐n(H2O) systems. For the first time, we test ANI potentials' abilities to reproduce solvation free energies using linear interaction energy (LIE) formulism by modifying the original LIE equation. Our results on ~250 different complexes show that the method can be accurate and have a correlation of R2 = 0.88–0.89 (MAE <1.0 kcal/mol) to the experimental solvation free energies, outperforming current end‐state methods. Moreover, it is competitive to other conventional free energy methods such as FEP and BAR with 15‐20 × fold reduced computational cost. [ABSTRACT FROM AUTHOR]

Methods: The intermolecular interactions between the heavy-atom analogues of acetylene T2H2 (T = Si, Ge, Sn, Pb) and HCN have been investigated by theoretical calculations at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVDZ level. Results: The global energy minimum of T2H2 is the butterfly structure A, and another energy minimum is the planar structure B. Both structures A and B exhibit the dual behavior when binding with HCN. The various hydrogen bond (HB), dihydrogen bond (DB) and tetrel bond (TB) complexes can be found according to the MEP maps of T2H2. One TB and three HB complexes formed between structure A and HCN can be located for Si2H2 and Ge2H2. One TB, two HB and one DB complexes formed between structure A and HCN can be located for Sn2H2 and Pb2H2. Four TB and one HB complexes formed between structure B and HCN can be located for all the T2H2. The geometries and binding strengths of the complexes are compared and analyzed. Conclusions: The interactions in these complexes are generally weak, and the interaction energies of these complexes range from −0.53 to −8.23 kcal/mol. The interaction energies of the TB complexes are larger than those of the corresponding HB and DB complexes for structure A···HCN systems. The relative binding strength of the four TB complexes exhibits different order for different structure B···HCN systems, which is consistent with the MEP maps of the isolated monomers. [ABSTRACT FROM AUTHOR]

Clay particle deposition in porous media is critical in many geotechnical applications that rely on filtration. The deposition of particles in the filter medium can result in clogging, which causes a reduction in the hydraulic conductivity of the filter medium. Particle attachment and detachment are a function of the interaction energy between clay particles and the filter bed material, which is frequently sand. These mechanisms are governed by the size of the clay particles as well as the solution chemistry. Batch kinetic adsorption tests were carried out to investigate the impact of ionic strength on the attachment of kaolinite to silica sand grains. Significant attachment of kaolinite was observed as ionic strength of the pore fluid increased and as the size of silica particles decreased. The short-term deposition of clay particles was not sensitive to ionic strength; however, in contrast, long-term deposition was a strong function of ionic strength. [ABSTRACT FROM AUTHOR]

To explore the influence of freezing and thawing on drainage behaviour for porous asphalt pavement (PA), molecular dynamics simulation was applied to study the interaction between asphalt and water. Based on the establishment and verification of micro models for asphalt (virgin and aged) and water (ice, ice–water mixture and water), the micro behaviour of interfacial transition zone was intuitively observed. Combined with the multi-gradient experiment results, the micro influence mechanism of freezing and thawing on drainage behaviour of porous asphalt pavement was revealed. The results show that the interaction energy of asphalt–water changes with the occurrence of freeze–thaw. The interaction energy (attraction) between aged asphalt and water is enhanced, which leads to water-induced distress more easily. In addition, with the occurrence of freeze–thaw, the relative concentration of hydrogen atoms at the interfacial transition zone gradually increases, while the fluctuation of carbon atoms increases. The results provide a micro-mechanism for the study of drainage behaviour of porous asphalt pavement under freezing and thawing, which has certain theoretical significance and practical value. [ABSTRACT FROM AUTHOR]

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Pyrolysis-assisted dispersion for electrode particles from spent lithium-ion batteries (LiBs) is an extremely effective means to improve subsequent recovery efficiency. The relationship between interaction energy and surface properties of electrode particles has been constructed. The XRD results demonstrated that the mineral phases of both anode and cathode particles, mainly composed of graphite and LiCoO 2 respectively, had little changes using a pyrolysis process at 550 ℃ for 30 min. Nevertheless, pyrolysis treatment could remove the organic film of electrode particles to alter the surface properties effectively. With the organic film removal by pyrolysis, the subtraction value on the contact angle of cathode and anode particles was increased from 9.3° to 35.44°, while the difference in charge ability was increased from 0.35 mV to 23.21 mV. The interaction energy calculations also illustrated that the electrostatic repulsion energy and hydrophilic repulsion energy both increased significantly, resulting in the total interaction energy of anode and cathode particles being 1.7 and 3.8 times that before pyrolysis. Furthermore, the total interaction energy, which determined the dispersing of electrode particles in suspension, mainly depended on the hydrophilic force. The findings might propose an alternative means for enhancing particle interaction to improve the recycling efficiency of electrode materials from spent LiBs by flotation. [Display omitted] [ABSTRACT FROM AUTHOR]

• Measure the solubility of DNTF in the range of 293.15–333.15 K in nine pure solvents by laser dynamic method. • Use four models to correlate solubility in order to expand the applicability of solubility. • Use solubility parameters to explain the regular pattern of the solubility of DNTF in nine pure solvents. • Calculate the thermodynamic parameters (enthalpy, entropy and Gibbs free energy) of DNTF. The atmospheric pressure solubility of 3,4-Bis(3-nitrofurazan-4-yl)furoxan(DNTF) in 9 pure solvents (n-propanol, isopropanol, propionic acid, formic acid, carbon tetrachloride, o-xylene, chlorobenzene, anisole, and 1,2-dichloroethane) was studied using dynamic laser monitoring method. Using various equations, including the modified Apelblat equation, Van't Hoff equation, Yaws model, NRTL model, and Wilson model to establish the relationship between solubility data. The modified Apelblat equation was used to effectively correlate the solubility data, demonstrating a strong correlation between the equation and experimental data. Meanwhile, Hansen solubility parameters analysis and density functional theory calculation of interaction energy were also used to investigate the mechanism of the solubility behavior of DNTF in different solvents. In addition, apparent thermodynamic parameters such as standard dissolution enthalpy, standard dissolution entropy, and standard Gibbs free energy of DNTF in these solvents were calculated. These findings provide valuable insights for future research on DNTF crystallization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The solvation behavior of modified siloxanes in supercritical CO 2 was investigated. • High temperature and low pressure hinder the solvation of modified siloxanes. • Van der Waals forces and electrostatic interactions control intermolecular interactions. • The thickening mechanism of modified siloxanes in supercritical CO 2 has been studied. Supercritical carbon dioxide (ScCO 2) fracturing fluids have been limited in their application in unconventional reservoirs due to their weak proppant-carrying capacity resulting from their low viscosity. Consequently, numerous scholars have focused on modifying siloxanes to enhance their solubility and thickening performance in ScCO 2. In this paper, the cohesive energy density, interaction energy, radial distribution function, shear viscosity and electrostatic potential distribution of modified siloxane with ScCO 2 were calculated using molecular dynamics simulation. The effects of different temperatures and pressures on the dissolution and thickening ability of modified siloxanes in ScCO 2 were investigated. The simulation results indicate that high temperature and low pressure have limited effects on promoting the solubility of modified siloxanes in ScCO 2 , with temperature exerting a more significant influence on solubility behavior than pressure. Additionally, P D4H+TMPTMA is less soluble in ScCO 2 compared to P D4H+TAIC. The binding energy of ScCO 2 and modified siloxanes decreases with increasing temperature but increases with increasing pressure. Van der Waals interactions and electrostatic interactions play decisive roles in the solubility of modified siloxanes in ScCO 2. Finally, the thickening mechanism of modified siloxanes in ScCO 2 was elucidated based on molecular structure and binding energy interactions. In summary, this paper aims to provide options and assistance in synthesis of better ScCO 2 thickeners for unconventional reservoir fracturing applications through the study of modified siloxanes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The more C layers, the greater the interaction energy between aq-AgCo/C. • The interaction between aq-AgCo/C hinders the diffusion of aq. • There are bonding and non-bonding interactions, and non-bonding is dominant. Using carbon-supported silver-cobalt (AgCo/C) electrode as the electrocatalyst in fuel cell (FC), it has good electrocatalytic performance for NaOH solution (aq), however, the mechanism of the interaction between aq and AgCo/C electrode is not clear. In this work, layered models (L1, L2, L3) of the interaction between them were constructed, and molecular dynamics (MD) simulation was carried out using Materials Studio (MS) software to explore their interaction rule and reveal the interaction mechanism. At 298 K, the results showed that the interaction force between aq and AgCo/C electrode is mutually attracted, and the order of the absolute value of the interaction energy is L3 ≫ L2 > L1, indicating that the electrocatalytic effect of the composite electrode with 4 carbon-supporter layers is obviously stronger than that of the composite electrode with 3 and 2 carbon-supporter layers, which is consistent with the experimental conclusion. Their interaction inhibits the diffusion of Na+ ions and water molecules− in aq. There is no bonding between AgCo(AgCo/C)-OH−(aq) and AgCo(AgCo/C)-Na+(aq) in the short-range region, while there is non-bonding in the long-range region. Bond formation is a common occurrence between H 2 O(aq)-OH−(aq) in the short-range region, but it is weak in the long-range region. Research and development of cathode materials for fuel cells will be supported by these theoretical results. [ABSTRACT FROM AUTHOR]

Building upon the CO 2 -ECBM technology (CO 2 -Enhanced Coaled Methane Recovery Technology), hot flue gas injection for displacing coalbed methane has been proposed to improve methane recovery efficiency and reduce the costs associated with CO 2 capture during the displacement process as well as flue gas desulfurization and denitrification at coal-fired power plants. To explore the microscopic mechanisms of displacement and the influence of functional groups, this study used Molecular Dynamics (MD) and Grand Canonical Monte Carlo (GCMC) methods with Materials Studio software to model slit pores grafted with various functional groups for gas adsorption simulations. The adsorption characteristics of eight key functional groups (-C=OCH₃, -COOH, -CH₂OH, Ar-OH, -OCH₃, -C 6 H 6 , -CH₃, -CH₂) for hot flue gas and methane were analyzed, focusing on adsorption strengths and underlying mechanisms. Simulations of the dynamic injection of hot flue gas were conducted, monitoring energy changes and methane density distribution to establish the relationship between adsorption strength and the difficulty of coalbed methane (CBM) displacement. The results indicate that in this simulation, the methane displacement efficiency using hot flue gas to displace coalbed methane exceeded 98%, demonstrating significantly better displacement performance compared to the use of pure carbon dioxide or nitrogen. Although both methane and hot flue gas show that greater interaction energy with pores makes displacement more difficult, the underlying causes differ. A comparison of the interaction energies between different functional groups and various gases reveals that oxygen-containing functional groups (-C=OCH 3 , -COOH, -CH 2 OH, Ar-OH, -OCH 3) are unfavorable for the displacement of coalbed methane by wet hot flue gas, whereas aliphatic hydrocarbons (-CH 3 , -CH 2) facilitate the displacement process. • The dynamic injection of hot flue gas displacing methane in narrow pores was simulated. • The adsorption strength of major oxygen-containing functional groups and aliphatic hydrocarbons for different gases was investigated. • Energy changes during the displacement process were monitored, establishing a link between gas adsorption and displacement behavior. • Oxygen-containing functional groups exert an inhibitory effect on the displacement of coalbed methane by hot flue gas, whereas alkanes behave conversely. [ABSTRACT FROM AUTHOR]

• Wetting behaviors on quartz exposed to varying gases is explored from molecular level. • CA presents an order of CO 2 > CH 4 > H 2 due to a faster decay in gas–solid interaction. • Introduction of salt ions leads to a less hydrophilic surface despite the gas type. • Ions-induced wettability alteration is mainly attributed to the augmented gas–water IFT. Understanding the wetting behaviors of water on quartz surfaces and underlying mechanisms when immersed in varying gas environments is crucial for the efficient implementation of geological engineering projects, such as H 2 gas geo-storage, natural gas production, and greenhouse gas geo-sequestration. In the present work, classical molecular dynamic (MD) simulations are applied to investigate the deionized (DI) water and brine (with a salinity of ∼1.5 M and ∼3.5 M) wettability of quartz surfaces and interfacial properties in the presence of various gas species (i.e. , H 2 , CH 4 , and CO 2) under a typical geological condition (333K and 20 MPa). The inherent mechanisms regulating surface wettability are revealed by Young's equation and interaction energy analysis. Thanks to the strong electrostatic interaction, water forms several adsorption layers on quartz surfaces, whereas gas molecules are mainly adsorbed on the region where the water is not accessible through van der Waals interaction. The presence of salt ions has negligible effects on water and gas distributions as they tend to be depleted from the surface area. When immersed in varying gas species, the contact angle (CA) of water on quartz follows an order of CO 2 > CH 4 > H 2 due to the faster decay in gas–solid interaction compared with gas–water interaction. Increasing salt ions is generally unfavorable for the spreading of water on quartz surfaces regardless of gas types resulting in a larger CA value, which is primarily attributed to the augmented gas–water interfacial tension. This study provides important insights into the wettability behaviors of water on quartz surfaces under varying gas conditions and deepens the understanding of the molecular origin of wetting characteristics on quartz surfaces, which is beneficial for explaining relevant phenomena and leading engineering practice. [ABSTRACT FROM AUTHOR]

Achieving the efficient separation of Li+ and Mg2+ ions remains a significant challenge. To address this issue, a Ca2+-supported graphene membrane was engineered and evaluated through molecular dynamics simulations. The separation mechanism of Li+/Mg2+ in the Ca2+-supported graphene membrane was investigated by analyzing the dehydration behavior as well as the interfacial interactions between ions and the graphene membrane. The Ca2+-supported graphene membrane exhibits well separation performance for Li+ and Mg2+ mixtures, and the separation efficiency of the Ca2+-supported graphene membrane for Li+/Mg2+ mixture increases first and then decreases with the increase of Ca2+ ion number inserted into the membrane. Li+ ions display heightened permeability and reduced ion rejection, which can be attributed to their relatively weaker interaction with the graphene sheets compared to Mg2+ ions, facilitating smoother penetration. Furthermore, Li+ ions are intended to form smaller sizes with Cl− ions at the entrances of the Ca2+-supported graphene membrane, mitigating size-related effects. Additionally, their weaker interactions with water molecules, facilitate the dehydration process of Li+ ions. [Display omitted] • Increased Ca2+ intercalation increases Li+/Mg2+ separation first and then decreases. • The hydrating effect and interfacial interactions affect ions' permeation behavior. • The hydrating effect and interfacial interaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defining the captured state of shale oil near the wall. • CO 2 stripping shale oil on kaolinite surface is superior to kerogen. • Kaolinite adsorbed CO 2 is unstable, and the attraction is easily converted to repulsion. • The "bullet head" structure formed by medium component can severely block the pores. • CO 2 can effectively deionize "bullet head" structure by miscible phase, viscosity reduction, and swelling. CO 2 huff-n-puff is a promising approach for enhanced recovery and sequestration of CO 2 in shale reservoirs. Here, we investigate three stages of CO 2 huff-n-puff promoting shale oil mobilization from organic-inorganic nanopores by molecular dynamics simulation. We first defined the captured state of shale oil based on interaction energy and density. The results show that the capture range of kerogen for shale oil was 3.5 times that of kaolinite, but due to the presence of active components, the adsorption density and interaction energy of shale oil on the surface of kerogen were lower than those of kaolinite. In the CO 2 soaking stage, although CO 2 has a desorption effect on shale oil near two kinds of walls, stripping shale oil near the inorganic surface was more effective than the kerogen surface. In addition, when the CO 2 adsorbed on the surface of kaolinite slightly deviates from the equilibrium position, the attraction effect of kaolinite on CO 2 will be transformed into the repulsion effect, making CO 2 adsorption unstable and easy desorption. In the CO 2 puff stage, an interesting result in the 10 MPa CO 2 puff pressure, as opposed to the ideal model, demonstrates a significant capacity of CO 2 to efficiently dissociate the "bullet head" structure of the medium component blocking the pore exits through a synergistic effect of miscible phase action, viscosity reduction, and swelling, resulting in a notable enhancement of overall shale oil recovery by more than 37%. This work first investigates the CO 2 huff-n-puff mobilization of shale oil from multiple stages and effectively reveals the promoting effects of CO 2 on different components of shale oil in each stage of huff-n-puff. [ABSTRACT FROM AUTHOR]

Roseolumiflavin is a deep red microcrystalline derivative of isoalloxazine that exhibits a weak photophysical activity in the solid state. In aqueous as well as in acidic solution of formic or acetic acid, respectively, it tends to form solvates. Herein, we present a set of binary and ternary roseolumiflavin solvates including one hydrate and a solvate hydrate. The impact of the solvent on solvate formation along with an in-depth structural analysis was investigated. Calculations of the lattice energies provide insight into the phase stability of the evaluated systems showing an energetic benefit for all solvates with values up to −395.82 kJ/mol. The total interaction energies between molecules calculated via Crystal Explorer further identified cofacial π···π stacks to be the most strongly bonding fragments in the crystal lattices for all systems except the formic acid solvate, followed by remarkably weaker hydrogen-bonded arrangements. The energetic contributions of single intermolecular interactions within the fragments are evaluated by an atoms-in-molecules approach. It is shown that physicochemical properties, such as thermal stability, can be tuned depending on the incorporated solvent molecules despite a high decomposition temperature of the chromophore.

Molecular structures of four 6-chloro-coumarins have been optimized using DFT/B3LYP method. The energy of the HOMO and LUMO has been predicted. Lattice energy analysis (based on CLP-PIXEL module) in case of each structure indicates that the crystal packing stability is mainly derived by C–H...O and π...π type interactions. Besides this, the intermolecular interactions of the type C–H...Cl, C–H...π, C–Cl...π and C–Cl...O also exist in the crystal structures. Quantitative analysis of each intermolecular interaction using 3D-Hirshfeld surfaces and corresponding 2D-fingerprint has been carried out. [ABSTRACT FROM AUTHOR]

This study discusses the technology of coal slime recovery for preparing ultra-clean coal (UCC). X-ray diffraction analysis (XRD) and scanning electron microscopy combined with energy dispersive spectroscopy (SEM-EDS) were used to analyze the characteristics of coal slime and to explore the types of minerals and embedded characteristics of coal slime. The particle interaction energy and contact angle analysis were used to determine the UCC preparation process through dry and wet grinding dissociation comparison and shear flocculation flotation tests, combined with zeta potential measurements. The results showed that the inorganic minerals in the slime were mainly kaolinite clay minerals, which were easy to mud in the pulp and needed grinding. The calculation results of the interaction energy indicated that the interaction force of dry-ground slime in the pulp was small, and flocculation was more likely to occur. The wet-ground product was subjected to three flotations to obtain UCC with an ash content of 0.95%. [ABSTRACT FROM AUTHOR]