Search Results (11)

In this study, we investigated the interaction of a dapagliflozin-containing medicinal product (the commercial drug Forxiga^®) with human serum albumin (HSA) at different temperatures using steady-state fluorescence spectroscopy, competitive displacement assays, UV–Vis absorption spectroscopy, and thermodynamic analysis. Increasing concentrations of Forxiga induced a gradual, concentration-dependent quenching of the intrinsic fluorescence of HSA (${\lambda }_{\mathrm{ex}}=284$ nm; ${\lambda }_{\mathrm{em}\max }\approx 334$–339 nm), indicating perturbation of the microenvironment surrounding Trp-214 located in subdomain IIA. Stern–Volmer analysis showed that the quenching constants were temperature-dependent. Meanwhile, the high apparent bimolecular quenching constants suggested a predominantly static quenching mechanism associated with ground-state complex formation. By performing a modified Scatchard-type double-logarithmic analysis, we identified a primary binding site, particularly at lower temperatures. Van’t Hoff analysis revealed negative enthalpy and entropy changes. This indicates that the interaction was spontaneous and exothermic, mainly driven by hydrogen bonding and van der Waals forces. The competitive displacement assays confirmed preferential binding at Sudlow’s site I, in proximity to Trp-214. Additionally, the UV–Vis spectroscopy, supported by ligand-induced perturbation of aromatic residues, confirmed the absence of significant inner-filter effects. Differential scanning calorimetry suggested partial thermal stabilization of HSA upon ligand binding. This finding is consistent with the formation of a stabilized protein–ligand complex. These results suggest that Forxiga forms a relatively stable ground-state complex with HSA, primarily at Sudlow’s site I, and that the interaction is influenced by temperature-dependent conformational changes in the protein. Full article

High-entropy MAX (HE-MAX) phases represent a new class of layered ceramics that combine the multi-principal-element chemistry of high-entropy materials with intrinsic damage tolerance, electrical conductivity, and multifunctionality of conventional MAX phases. Despite their promise, the synthesis of HE-MAX phases remains fundamentally constrained by sluggish multicomponent diffusion, narrow thermodynamic stability windows, and strong competition from thermodynamically favored binary and ternary carbides, borides, and nitrides. These challenges are further exacerbated by the volatility of A-site elements under near-equilibrium processing conditions. This review positions self-propagating high-temperature synthesis (SHS) as an energy-efficient, non-equilibrium processing route capable of stabilizing selected entropy-driven MAX chemistries through ultrafast thermal excursions and rapid quenching. A unified thermodynamic–kinetic framework is developed to elucidate the interplay among reaction enthalpy, configurational entropy, combustion wave sustainability, and phase evolution in HE-MAX systems. Predictions of thermochemical adiabatic temperature are systematically correlated with experimental SHS studies to delineate phase stability boundaries, stoichiometric sensitivity, and the roles of diluents and transient liquid formation. Finally, practical design principles for scalable SHS synthesis of HE-MAX phases are outlined, alongside strategies for their selective exfoliation into high-entropy MXenes and a critical assessment of their emerging functional applications. Full article

This state-of-the-art review provides a comprehensive, critical synthesis of the rapidly expanding field of HECCs, emphasizing the unique scientific challenges that distinguish these materials from conventional ceramics and high-entropy alloys. Key challenges of HECCs include accurately predicting stable phases and quantifying resultant material properties, optimizing complex fabrication and processing techniques, and establishing a robust correlation between the intricate microstructural characteristics and macroscopic performance. Unlike previous reviews that focus on individual ceramic families, this article integrates the novel features, diverse applications, and recent developmental breakthroughs across carbides, nitrides, borides, and oxides to reveal the unifying principles governing configurational disorder, phase stability, and microstructure property relationships in HECCs. A key novelty of this review work is the systematic mapping of fabrication pathways, including CTR, PAS, SPS, and reactive sintering, against the underlying thermodynamic and kinetic constraints specific to multicomponent ceramic systems. The review introduces emerging ideas such as HEDFT, machine-learning-assisted phase prediction, and entropy–enthalpy competition as foundational tools for next-generation HECC design and performance analysis. Additionally, it uniquely presents densification behavior, diffusion barriers, defect chemistry, and residual stress evolution with mechanical, thermal, and tribological performance across the coating classes. By consolidating theoretical intuitions with experimental developments, this article provides a novel roadmap for predictive compositional design, development, microstructural engineering, and targeted application of HECCs in extreme environments. This work aims to support researchers and coating industries toward the rational development of high-performance HECCs and establish a unified framework for future research in high-entropy ceramic technologies. Full article

Norovirus is a leading cause of viral gastroenteritis worldwide and has been studied extensively from the perspective of life and biomedical sciences. However, no biothermodynamic analysis of Norovirus has been reported in the literature. Such an analysis would provide insights into the role of energetic constraints in the interactions between Norovirus and its host cells and other viruses. In this research, Norovirus was characterized from the aspect of chemistry and chemical thermodynamics, with the determination of its molecular formula, empirical formula, molar mass and thermodynamic properties (enthalpy, entropy, Gibbs energy) of formation. Based on these properties, biosynthesis reactions were formulated that show how Norovirus particles are synthetized inside host cells, and the thermodynamic properties of biosynthesis were determined. Moreover, the thermodynamic properties of the binding of Norovirus to its host cell receptor were determined. These were then used to develop a model of virus–host interactions at the cell membrane (antigen-receptor binding) and inside the cytoplasm (virus multiplication), with the phenomenological equations of nonequilibrium thermodynamics. Based on the model, an analysis of the virus–virus competition between Norovirus and Rotavirus was conducted. Full article

The application of thermochemically responsive polymer films in the biomedical field is a promising direction, particularly for controllable drug delivery. However, the mechanism governing the shape memory effect (SME) remains poorly understood due to the complex interactions between solvent molecules and polymer chains. Herein, we integrate the Flory–Huggins theory with the transition state model to investigate the plasticization effect of solvent on the thermodynamic behavior of polymers. By introducing the concept of phase transition, the dependences of the glass transition temperature, thermomechanical properties, and shape memory behavior of polymer films on the thermochemical stimuli are discussed. Our theoretical analysis reveals that the entropy of mixing promotes the occurrence of the SME, while the enthalpy of mixing exerts an inhibitory effect on this process. Consequently, the competition between the entropy of mixing and the enthalpy of mixing is the critical factor determining whether polymers exhibit the SME under different thermochemical conditions. The effectiveness of the proposed model is further validated by applying it to predict the shape memory behavior of acrylate copolymer films under different thermochemical conditions. This study is expected to provide a practical methodology for understanding the working mechanism of the thermochemically driven SME in polymer films. Full article

The surface wetting or coating of materials by polymers is crucial for designing functional interfaces and various industrial applications. However, the underlying mechanisms remain elusive. In this study, the wetting behavior of hydroxyl-terminated polybutadiene (HTPB) on a quartz surface was systematically investigated using computer simulation methods. A notable tip-dominant surface adsorption mode of HTPB was identified, where the hydroxyl group at the end of the polymer chain binds to the surface to initiate the wetting process. Moreover, it was found that with the increase in the degree of polymerization (e.g., from DP = 10 to 30), spontaneous adsorption of HTPB becomes increasingly difficult, with a three-fold increase in the adsorption time. These results suggest a competition mechanism between enthalpy (e.g., adhesion between the polymer and the surface) and entropy (e.g., conformational changes in polymer chains) that underlies the wetting behavior of HTPB. Based on this mechanism, two strategies were employed: altering the degree of polymerization of HTPB and/or regulating the amount of interfacial water molecules (e.g., above or below the threshold amount of 350 on a 10 × 10 nm² surface). These strategies effectively modulate HTPB’s surface wetting process. This study provides valuable insights into the mechanisms underlying the surface adsorption behavior of HTPB and offers guidance for manipulating polymer wetting processes at interfaces. Full article

Formation thermodynamic parameters for three cocrystals of carbamazepine (CBZ) with structurally related coformers (benzamide (BZA), para-hydroxybenzamide (4-OH-BZA) and isonicotinamide (INAM)) were determined by experimental (cocrystal solubility and competitive reaction methods) and computational techniques. The experimental solubility values of cocrystal components at eutectic points and solubility product of cocrystals [CBZ + BZA], [CBZ + 4-OH-BZA], and [CBZ + INAM] in acetonitrile at 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K were measured. All the thermodynamic functions (Gibbs free energy, enthalpy, and entropy) of cocrystals formation were evaluated from the experimental data. The crystal structure of [CBZ + BZA] (1:1) cocrystal was solved and analyzed by the single crystal X-ray diffractometry. A correlation between the solubility products and pure coformers solubility values has been found for CBZ cocrystals. The relationship between the entropy term and the molecular volume of the cocrystal formation has been revealed. The effectiveness of the estimation of the cocrystal formation thermodynamic parameters, based on the knowledge of the melting temperatures of active pharmaceutical ingredients, coformers, cocrystals, as well as the sublimation Gibbs energies and enthalpies of the individual components, was proven. A new method for the comparative assessment of the cocrystal stability based on the H-bond propensity analysis was proposed. The experimental and theoretical results on the thermodynamic parameters of the cocrystal formation were shown to be in good agreement. According to the thermodynamic stability, the studied cocrystals can be arranged in the following order: [CBZ + 4-OH-BZA] > [CBZ + BZA] > [CBZ + INAM]. Full article

The phase stability and elastic properties of paramagnetic (PM), ferromagnetic (FM) and antiferromagnetic (AFM) phases in L1₂-(Ni,Cu)₃(Al,Fe,Cr) alloy are first investigated using the exact muffin-tin orbitals (EMTO) method in combination with the coherent potential approximation (CPA). The result shows the AFM structure phase of the three is the most stable in the ground state. Calculated elastic constants show that all the phases are mechanically stable, and have uncovered that L1₂-(Ni,Cu)₃(Al,Fe,Cr) can achieve good strength and ductility simultaneously. Then, crucial thermal properties are described satisfactorily using the Debye–Grüneisen model, showing heat capacity, Gibbs free energy G, the competitive contribution of entropy −TS and enthalpy H exhibiting significant temperature dependences. Moreover, the magnetic phase transition thermodynamics was studied, which suggests that −TS has a primary contribution to Gibbs free energy and may play a key role in the phase transition. The present results can benefit the understanding of the mechanical, thermodynamic and magnetic properties of the L1₂ structure phase in 3d high-entropy alloys. Full article

The most commonly applied industrial synthesis of 4,4′-methylene diphenyl diamine (4,4′-MDA), an important polyurethane intermediate, is the reaction of aniline and formaldehyde. Molecular understanding of the 4,4′-MDA formation can provide strategy to prevent from side reactions. In this work, a molecular mechanism consisted of eight consecutive, elementary reaction steps from anilines and formaldehyde to the formation of 4,4′-MDA in acidic media is proposed using accurate G3MP2B3 composite quantum chemical method. Then G3MP2B3-SMD results in aqueous and aniline solutions were compared to the gas phase mechanism. Based on the gas phase calculations standard enthalpy of formation, entropy and heat capacity values were evaluated using G3MP2B3 results for intermediates The proposed mechanism was critically evaluated and important side reactions are considered: the competition of formation of protonated p-aminobenzylaniline (PABAH⁺), protonated aminal (AMH⁺) and o-aminobenzylaniline (OABAH⁺). Competing reactions of the 4,4′-MDA formation is also thermodynamically analyzed such as the formation of 2,4-MDAH⁺, 3,4-MDAH⁺. AMH⁺ can be formed through loose transition state, but it becomes kinetic dead-end, while formation of significant amount of 2,4-MDA is plausible through low-lying transition state. The acid strength of the key intermediates such as N-methylenebenzeneanilium, PABAH⁺, 4-methylidenecyclohexa-2,5-diene-1-iminium, and AMH⁺ was estimated by relative pK_a calculation. Full article

This paper investigates the underlying driving force in strategic decision-making. From a conceptual standpoint, few studies empirically studied the decision-maker’s intrinsic state composed of entropy and uncertainty. This study examines a mutual information theory approach integrated into a state of qualia complexity that minimizes exclusion and maximizes the interactions of the information system and its dynamic environment via logical metonymy, illusion, and epigenetics. The article questions whether decision-makers at all levels of the organization are responding from the consciousness of an objective quale from a more subjective qualia awareness in the narrow-sense perspective of individual instances of their conscious experience. To quantify this research question, we explore several hypotheses revolving around strategic information system decisions. In this research, we posit that the eigenvalues of factor analysis along with the reduction in the uncertainty coefficients of the qualia entropy will be balanced by the quale enthalpy of our information theory structural equation model of trust, flexibility, expertise, top management support, and competitive advantage performance. We operationalize the integration of the aforementioned top management support, information systems competencies, and competitive advantage performance concepts into the qualia consciousness awareness and information theory quale framework. Full article

We analyzed the effect of the interfacial free energy on the thermodynamics of hydrogen sorption in nano-scaled materials. When the enthalpy and entropy terms are the same for all interfaces, as in an isotropic bi-phasic system, one obtains a compensation temperature, which does not depend on the system size nor on the relative phase abundance. The situation is different and more complex in a system with three or more phases, where the interfaces have different enthalpy and entropy. We also consider the possible effect of elastic strains on the stability of the hydride phase and on hysteresis. We compare a simple model with experimental data obtained on two different systems: (1) bi-phasic nanocomposites where ultrafine TiH₂ crystallite are dispersed within a Mg nanoparticle and (2) Mg nanodots encapsulated by different phases. Full article