The tautomerization of thymine between its keto and enol forms is a key event for spontaneous mutagenesis. While the intrinsic enol-to-keto conversion is kinetically hindered in the gas phase, the presence of a discrete microhydration environment can drastically alter this landscape. Our M06-2X free energy calculations indicate that the cluster with two water molecules provides the lowest Gibbs free energy barrier among the investigated hydrated systems. However, benchmark electronic calculations show that the energetic differences between the mono-, bi-, and trihydrated clusters are small. HOMA index and QTAIM analyses confirm that the third water molecule induces an offset between aromaticity and intermolecular stabilization, providing a structural basis for the observed kinetic stabilization of the rare tautomer in a hydrated environment.

Using the density functional theory (DFT) method, we studied the adsorption behaviour of different toxic quinone molecules, including anthraquinone (AQ), naphthoquinone (NQ), and pyrenequinone (PQ), on β-antimonide phosphorus (β-SbP) nanosheet. Initially, we ascertained the geometrical stability of β-SbP with the support of formation energy, phonon band maps, and ab initio molecular dynamics (AIMD). The electronic attributes of β-SbP are investigated using band structure and projected density of states (PDOS) maps, and the energy gap is calculated to be 2.265 eV. The adsorption of quinone molecules induces a relative band gap variation of 33% to 60%. Among the studied quinone molecules, PQ exhibits the highest variation of 60.26% and 58.10% in parallel and perpendicular orientations, respectively. Furthermore, the sensing performance of quinone pollutants on β-SbP material is assessed using adsorption energy, Mulliken charge transfer, sensitivity, selectivity, and work function. The outcomes revealed that the nature of adsorption (chemisorption or physisorption) as well as the significant charge transfer observed in the ranges from 0.148 to 1.038 e, depending on the orientation of molecules adsorbed on β-SbP. A noticeable variation in the work function is observed for complex PQ1, which is recorded as 14.75%. Our findings reveal that β-SbP nanosheets are highly sensitive to these toxic quinones, indicating their suitability as an efficient sensing material.

In this work a DFT modeling of various routes of hydrogenation of a non-conjugated bicyclic diene-norbornadiene (NBD)-was carried out using the all-electron scalar-relativistic approximation. According to calculations, the determining role in selective hydrogenation of NBD to norbornene (NBE) belongs to the type of palladium surface and adsorption configuration (exo or endo) of NBD and NBE molecules. Pd(111) surface shows selectivity in NBD adsorption, as well as activity in selective hydrogenation of NBD to NBE. Gibbs activation energies of hydrogenation of NBD to NBE and NBE to NB on Pd(111) differ by 4.3 kcal/mol in favor of the former route, which determines the selectivity of NBD hydrogenation. Formation of byproduct nortricyclane (NTC) involves overcoming a large Gibbs activation energy (29.2 kcal/mol), explaining its experimental trace amounts. Despite the high selectivity of Pd(100) surface in NBD adsorption, it is almost inactive in its hydrogenation. Notably, Gibbs activation energy of hydrogenation route of NBD to NBE on Pd(100) is 5.2 kcal/mol higher than that of NBE to NB on Pd(100) and 9.2 kcal/mol higher than that of NBD to NBE on Pd(111). Despite the significant increase in the adsorption energies of NBD and NBE, that was calculated with Grimme's D3 dispersion corrections, most of this difference is compensated when calculating activation energy.

Directional solute-solvent contacts can influence the electrostatic response of donor-acceptor chromophores, although such local effects are often represented only as averaged contributions in continuum solvent models. Quinolinylaminophenol (QMAP) in dimethyl sulfoxide (DMSO) was examined as an explicit first-shell microsolvation model to clarify how local solvent organization couples to QMAP conformation and dipolar response. The Car-Parrinello molecular dynamics trajectory indicates a geometric reorganization around 12-13 ps, accompanied by changes in the first-shell DMSO dipolar arrangement. Within the limitations of the finite microsolvated model, these results suggest that transient first-shell solvent organization contributes to the modulation of the local electrostatic environment of QMAP, rather than acting only as a static dielectric background.

Asphaltene aggregation and deposition pose major challenges in crude oil transport and processing. While extensive experimental studies have explored mitigation strategies, nanomaterials-particularly carbon nanotubes (CNTs)-have emerged as promising inhibitors due to their ability to adsorb asphaltenes and limit their clustering. However, experimental approaches provide limited insight into molecular-scale mechanisms. To address this, molecular dynamics (MD) simulations were performed to investigate interactions between model asphaltenes and CNTs in a toluene/heptane solvent. Five systems were studied: pristine CNTs and CNTs functionalized with carbamoyl (CONH2), methylcarbamoyl (CONHCH3), hydroxymethyl (CH2OH), and carboxylate (COO[-]) groups. Intermolecular interactions and aggregation behavior were analyzed using radial distribution functions (RDF), solvent-accessible surface area (SASA), cluster analysis, hydrogen bonding, and interaction energy decomposition (van der Waals and electrostatic contributions). Results show that CNTs significantly modify asphaltene aggregation, with carboxyl-functionalized CNTs exhibiting the strongest inhibition effect. This performance correlates with enhanced specific interactions between functional groups and asphaltene molecules, leading to reduced aggregation.

Erectile dysfunction (ED) significantly affects male psychosocial health and has an increasing incidence. Although phosphodiesterase 5 (PDEi-5) inhibitors are the first-line therapy, the occurrence of visual side effects resulting from cross-inhibition of the PDE-6 isoform limits their adoption. In this context, the plant Veronica anagallis-aquatica L. emerges as a promising source of bioactive therapeutic compounds. This work investigated the inhibitory potential and selectivity of eight iridoid glycosides from this species against PDE-5 and PDE-6. The results identified catalposide as the most potent ligand, exhibiting an affinity energy of -8.6 kcal/mol against PDE-5, surpassing the reference drug Vardenafil (-8.3 kcal/mol) and showing high selectivity towards PDE-6. Trajectory analyses confirmed the robustness of the catalposide-PDE-5 complex, which exhibited smaller structural fluctuations than the commercial control. Despite initial predictions indicating low oral bioavailability, structural optimization through increased sp3 fraction proved to be a viable strategy for enhancing membrane permeability. In conclusion, the findings position catalposide as a promising prototype for the development of more selective and safe drugs for the treatment of ED.

Naringenin is a natural flavonoid compound with potential pharmaceutical use that is limited by its low aqueous solubility and bioavailability. In this work, we used an in silico drug delivery approach to screen natural deep eutectic solvents (NaDESs) that may improve solubility, membrane affinity, and predicted relative release of naringenin from 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes. Of all systems screened, betaine-based NaDESs were found to provide the best solubilization efficiency while choline chloride-caffeic acid provided the most stabilizing membrane affinity. Drug-membrane interactions characterized by free-energy, intermolecular interaction, and permeability calculations were shown to be dependent on the NaDES composition. In particular, a tunable relationship between hydrogen-bonding and van der Waals (vdW) interactions was shown to dictate encapsulation and Predicted relative release behavior allowing for rational computational selection of NaDESs to enhance liposomal delivery of poorly water-soluble drugs.

Monolayer MoSe2 is a promising material for gas sensing; however, its weak interactions with nonpolar light hydrocarbons inherently limit its sensitivity and selectivity. In this study, first-principle calculations were employed to elucidate how substitutional transition-metal substitution regulates the adsorption of CH4, C2H4, and C2H6 on MoSe2. The incorporation of V, Cr, Mn, Fe, Co, and Ni introduces dopant-specific d-derived states near the Fermi level, thereby reconstructing the local electronic structure and modulating adsorbate-surface coupling. Across the investigated systems, the adsorption strength follows the order C2H4 (-0.67 to -0.98 eV) > C2H6 (-0.34 to -0.58 eV) > CH4 (-0.24 to -0.42 eV), with corresponding charge-transfer ranges of 0.14-0.20, 0.08-0.12, and 0.04-0.07 e, respectively. The substantially stronger interaction with C2H4 originates from π-d hybridization, whereas saturated σ bonding framework of CH4 and C2H6 limits orbital overlap with the dopant-derived states. These results establish a direct relationship between dopant-induced electronic states and hydrocarbon adsorption, providing a theoretical basis for the rational design of MoSe2-based sensors with improved sensitivity toward hydrocarbons.

The development of efficient sensing platforms for highly toxic gases remains a critical challenge in environmental monitoring and industrial safety. Despite the remarkable progress of two-dimensional heterostructures, their temperature-dependent gas-sensing behavior remains poorly understood, limiting their practical applicability. To address this gap, the gas-sensing performance of in-plane In2SSe/Al2SSe (X/Y), In2SSe/Al2SSe/In2SSe (X/Y/X), and Al2SSe/In2SSe/Al2SSe (Y/X/Y) heterostructures was systematically investigated over a wide temperature range. Interface engineering effectively modulates the electronic structure and adsorption behavior, resulting in enhanced sensing performance. The Y/X/Y heterostructure exhibits the highest response toward Cl2 (17,521.68 at 298 K), whereas ClCN shows the strongest adsorption (- 2.46 eV). These findings demonstrate the potential of interface-engineered Janus heterostructures as thermally robust platforms for next-generation toxic-gas sensing.

We report a comparative investigation of the structural, vibrational, and thermoelectric properties of aluminum nitride (AlN) across different dimensions (3D, 2D, and 1D) using density functional theory (DFT). While 3D AlN is a well-known wide-bandgap insulator, reducing the dimensionality to 1D nanotubes triggers that a (14,0) significant transition in electronic and transport behavior. Our results demonstrate that (14,0) nanotube exhibits exceptional thermoelectric efficiency at elevated temperatures (1300-1900 K). The 1D nanotubes, for example, have a power factor of 23Wm[-1] K[-2] at 1900 K, which is much better than the 2D monolayer. These results indicate that low-dimensional AlN structures are promising options for specialized energy harvesting in very hot places.

Platelet inflammatory tether (PITT) formation under pathological shear is a central driver of thrombo-inflammation and bleeding complications in severe infections, yet current antiplatelet therapies lack selectivity because they target equilibrium integrin affinity rather than force-dependent adhesion dynamics. The mechanistic origin of catch-bond stabilization in integrin αIIbβ3 under inflammatory shear, and its separation from physiological hemostatic adhesion, therefore remains unresolved.

Trivalent chromium exhibits a dual nature. It acts as a necessary micronutrient for lipid and carbohydrate metabolism at low levels in the body, but causes dangerous genotoxic harm at higher thresholds. Hence, precise tracking of trace trivalent chromium is absolutely essential. Compounding this, its intracellular detection remains highly obstructed by paramagnetic fluorescence quenching and a deficiency in selective probes. Addressing this material and analytical challenge, this work reports the development of an ultrasensitive "turn-on" fluorogenic chemosensor utilizing a novel azo-based dye, 2-[(E)-(4-methylphenyl)diazenyl]phenol (MPDP). Unlike traditional methods restricted to microgram boundaries, this newly developed strategy establishes a wide dynamic linearity descending to an extraordinary femtogram detection limit. The probe operates via a chelation-enhanced fluorescence (CHEF) pathway at pH 9.0, successfully validating chromium(III) quantification in plant matrices. Furthermore, integration of density functional theory (DFT) and non-covalent interaction (NCI) analysis successfully maps out the precise, thermodynamically favored octahedral coordination mechanics driving its extreme metal selectivity.

The antiradical activity of 1-hydroxy-anhydrolycorin-7-one (HAlc) and anhydrolycorin-7-one (Alc), two alkaloids isolated from Lycoris aurea, was theoretically investigated toward HOO• radical scavenging in aqueous and lipid-like environments. Thermodynamic analysis showed that HAlc is more favorable than Alc as a radical scavenger, mainly due to the additional hydroxyl group, which enhances both hydrogen atom donation and deprotonation ability. Among the investigated sites, the 2-OH group of HAlc displayed the lowest BDE and PA values and the most negative Gibbs free energy changes, indicating its key role in radical quenching. In pentyl ethanoate, HAlc scavenges HOO• predominantly through the fHAT mechanism at the 2-OH position, with an overall rate constant of 4.29 × 10[6] M[-][1] s[-][1], approximately two orders of magnitude higher than that of Alc. In water, acid-base speciation strongly affects the scavenging mechanism. Although the neutral forms are dominant at physiological pH, the minor monoanionic species govern the overall kinetics through a highly efficient SET pathway. HAlc exhibited an overall aqueous rate constant of 3.04 × 10[8] M[-][1] s[-][1], about 16 times higher than Alc and higher than common antioxidant references such as Trolox and ascorbic acid. These results identify HAlc as a promising natural antiradical agent, especially under physiological aqueous conditions.

Melanin-like dopamine oligomers are promising biomaterials due to their biocompatibility and metal-chelating ability. In this work, Zn[2+]-chelated melanin-related structures were investigated to clarify the effects of metal coordination on their electronic structure. The results indicate that Zn[2+] coordination induces significant electronic polarization, modifies local reactivity patterns, and activates the coordination sites. The theoretical results are also consistent with available spectroscopic observations, providing molecular-level insight into the antibacterial behavior of these complexes and supporting the design of related bioactive materials.

This computational study investigates the molecular-level interaction between asphaltene (AO) nanoaggregates and the amphiphilic 1-(octylamino)propan-2-ol (OAP) inhibitor using density functional theory (DFT) calculations and complementary experimental analysis. Quantum theory of atoms in molecules (QTAIM) analysis indicates that OAP interacts with the AO surface through non-covalent interactions, with binding energies reaching - 24.67 kJ/mol and |VB|/GB ratios below unity. Electron localization function (ELF), localized orbital locator (LOL), non-covalent interaction (NCI), and highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO-LUMO) analyses suggest charge redistribution and electronic complementarity within the OAP-AO complex, supporting the proposed steric shielding mechanism. Complementary dynamic light scattering (DLS) measurements showed a reduction in the median aggregate size from 42.4 to 17.7 nm following OAP addition, which may indicate improved aggregate dispersion and enhanced colloidal stability. Collectively, the computational and experimental findings provide molecular-level insight into the proposed stabilization mechanism of the OAP-AO system and contribute to a better understanding of asphaltene inhibitor-aggregate interactions.