Search Results (929)

Background/Objectives: Recent studies have shown that the solubilisation of poorly water-soluble drugs can be enhanced by using infant formula as a lipid-based formulation. In those studies, digestion of the triglycerides in infant formula to produce more polar lipids, namely fatty acids and monoglycerides, produced a high-capacity solubilisation environment for weakly basic drugs such as clofazimine, driven mainly by ion-pairing of the fatty acid with the drug. However, digestion of lipid-based formulations is not expected to provide the same effect for nonionised or acidic drugs and in fact may present a reduced solubilisation capacity for weakly acidic drugs. Methods: In this study, a weakly acidic drug, tolfenamic acid, was dispersed in reconstituted infant formula, and the infant formula was digested under in vitro simulated intestinal conditions. The quantity of tolfenamic acid that was solubilised in the infant formula during digestion was determined by high-performance liquid chromatography and small-angle X-ray scattering. Results: Unexpectedly, digestion of the infant formula increased the solubilisation capacity for tolfenamic acid. Reconstituting infant formula at a higher fat content also increased the rate and extent of solubilisation of tolfenamic acid during digestion. The quantity of tolfenamic acid that was solubilised during digestion correlated approximately linearly with the quantity of free fatty acids produced during digestion. Conclusions: These results show that a weakly acidic drug can also exhibit digestion-driven solubilisation in a lipid-based formulation in the absence of ion-pairing and highlights the need to better understand drug response to digestion of lipid-based foods and formulations, and their versatility as a formulation option even for poorly water-soluble acidic drugs. Full article

This study investigates the inhibitory effects of alkali metal chlorides lithium chloride, sodium chloride and potassium chloride (LiCl, NaCl, and KCl) on sodium dodecyl sulfate (SDS) foams, focusing on the transition from interfacial to bulk-driven destabilization mechanisms. The research demonstrates that foam collapse at high electrolyte concentrations is governed by a massive increase in bulk cohesive pressure and specific ion-pairing (SIP), which leads to interfacial dehydration and the mechanical decoupling of the surface from the bulk phase. It is shown that while surface adsorption reaches a plateau, the thermodynamic state of the solvent becomes the primary driver for film drainage. The results indicate that KCl acts as the most potent defoamer due to its optimal matching of water affinities with the surfactant head groups. These findings provide a new theoretical framework for understanding foam stability in concentrated electrolytic environments, emphasizing the role of bulk cohesive stress over traditional interfacial elasticity. Full article

In this study, an ion-pair reverse-phase high-performance liquid chromatography–electrospray ionization mass spectrometry (RP-HPLC-ESI-MS) method was optimized and validated for purity determination for the quality control of the proposed generic nusinersen oligonucleotide drug substance and drug product. The optimization and considerations of sample preparation, chromatographic and mass spectrometry conditions are discussed. The limit of detection was 2.5 × 10⁻⁵ mg/mL and the limit of quantitation was 4.9 × 10⁻⁵ mg/mL. The linearity of the signal (XIC) for all impurities was linear with correlation coefficients of R² ≥ 0.9669. This study, associated with the development of therapeutic oligonucleotides, examines the subject of product-related impurities. The authors consider an ion-pair reverse-phase high-performance liquid chromatography in combination with mass spectrometry for impurity quantitative control. This study contributes to the field by elucidating several critical aspects that, while previously unaddressed in the existing literature, are essential for developing effective analytical methods. Full article

Photo-Fenton technology is considered an effective method for removing organic pollutants from water. In this work, a novel Mn-doped FeWO₄ (Mn-FeWO₄) photocatalyst was synthesized via a one-step hydrothermal method and applied for the photo-Fenton degradation of tetracycline (TC). The optimal Mn-FeWO₄-0.05 achieved 100% removal of TC within 60 min under visible light irradiation with a degradation rate constant of 0.0793 min⁻¹, which is 4.5 times higher than that of pristine FeWO₄. Systematic characterization revealed that Mn²⁺ ions were successfully incorporated into the FeWO₄ lattice, inducing lattice expansion and narrowing the bandgap from 2.37 eV to 2.25 eV, while also adjusting the conduction and valence band positions. This modulation significantly enhanced visible light absorption and promoted the separation and migration of photogenerated electron–hole pairs. In addition, the Mn²⁺/Mn³⁺ and Fe²⁺/Fe³⁺ dual redox cycles ensure the continuous generation of reactive oxygen species. Radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy demonstrated that superoxide radicals (•O₂⁻) and photogenerated holes (h⁺) were the dominant reactive species, while singlet oxygen (¹O₂) and hydroxyl radicals (•OH) played auxiliary roles. Moreover, Mn-FeWO₄-0.05 exhibited excellent stability, strong anti-interference ability against common anions, and high degradation efficiency toward various pollutants. Full article

A library of twelve heteroditopic bis-urea and bis-thiourea receptors supported on Merrifield and Wang resins was prepared by solid-phase synthesis. The receptors incorporate dual hydrogen-bond-donor units for anion binding and a polyether spacer that simultaneously functions as a cation-binding site, enabling ion-pair recognition at the solid–liquid interface. Molecular recognition studies were performed using several inorganic and tetraalkylammonium salts, and fluorescence changes were monitored by microplate measurements in DMSO and DMSO/H₂O (95:5, v/v). Univariate and factorial statistical analyses revealed statistically significant fluorescence changes and identified the structural variables governing guest recognition in each medium. Under the conditions examined, several systems exhibited reproducible ion-pair-induced fluorescence responses, highlighting the influence of receptor type and spacer architecture. These findings provide a basis for the rational optimization of supported receptors for sensing and extraction applications. Full article

Highly polar M-mol-X (M = alkali metal, mol = molecule, X = halogen) insertion complexes have been predicted to offer potential practical applications, including molecular interactions with light, ion-pair induced isomerization, etc. In the present work, the insertion complexes of the seven-membered, fused bicyclic norcaradiene and its monocyclic isomer trapped in Li-I, Na-I, and K-I counterion pairs were investigated using ab initio methods. The structures, stability, polarities, and simulated infrared spectra are analyzed and the effects of the insertion on the norcaradiene to cycloheptatriene isomerization process are examined. Furthermore, an uncommon bond between iodine and a fully substituted carbon atom is reported upon and hypothesized to be catalyzed by the presence of the cation in the insertion complexes. Full article

Magnetic resonance imaging (MRI) reconstruction from undersampled k-space data enables accelerated acquisition but leads to a severely ill-posed inverse problem. Although supervised deep learning methods have achieved strong performance, they typically rely on large paired datasets that are difficult to obtain in clinical practice. To address these limitations, we propose a dictionary-learning-inspired dAta-fRee deep generative modeling with Meta-Attention and implicit precoNditIoning for compressively sampled MRI (CS-MRI), termed ARMANI. Specifically, a meta-attention-augmented deep image prior (MA-DIP) generator performs a joint optimization over the latent input $\eta$ and the network parameter $\theta$, where $\eta$ is regularized via gradient-domain sparsity and $\theta$ is constrained by a ridge penalty, mirroring the adaptive estimation of sparse coefficients and an empirical sparsifying dictionary. Furthermore, we integrate a single-step pseudo-orthogonal projection to achieve implicit preconditioning, which modulates the loss landscape and mitigates ill-conditioning of the forward operator. Experimental results demonstrate that ARMANI consistently outperforms existing SOTA data-free and self-supervised methods, and, with limited training data, achieves performance comparable to or slightly better than the supervised benchmark MoDL, with effective artifact suppression and faithful recovery of fine structural details. Overall, ARMANI shows strong scalability and potential for practical deployment in fully data-free CS-MRI reconstruction scenarios. Full article

The photoelectrochemical splitting (PEC) of water provides a direct route to converting solar energy into storable chemical fuels. When illuminated, a semiconductor photoelectrode can absorb light and generate electron-hole pairs, which participate in interfacial redox reactions at the semiconductor-electrolyte junction. Therefore, to achieve high-performance PEC, photoelectrodes with optimized optical absorption and charge have been explored. This review analyzes recent fabrication strategies used to design photoelectrodes for the PEC dissociation of water. Physical fabrication techniques, including pulsed laser deposition, magnetron sputtering, and physical vapor deposition, allow for precise control of film thickness, crystallinity, and defect density, critical parameters for efficient charge transport. Typically, in physical methods, reported photocurrent densities span from ~10⁻² to 10¹ mAcm⁻², depending on the semiconductor material, nanostructure design, and interfacial engineering strategies. Chemical synthesis methods, such as hydrothermal growth, successive ion layer adsorption and reaction, and microemulsion techniques, provide greater compositional flexibility and enable controlled doping, surface functionalization, and the formation of nanostructured morphologies. Finally, hybrid fabrication strategies integrate physical and chemical processes within a single synthesis framework to combine structural precision with compositional tuning capabilities. These approaches enable the development of advanced architecture such as heterojunctions, core–shell nanostructures, and catalyst-modified interfaces, which enhance light absorption and optimize interfacial transfer. Furthermore, theoretical and computational tools are here analyzed as complementary approaches that guide the rational design and optimization of photoelectrochemical materials and devices. Full article

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have become a global environmental concern due to their extreme persistence and toxicity. In this study, perfluorooctanoic acid (PFOA) was removed from aqueous solutions using porous carbon adsorbents synthesized from peach stones. The novelty of this work lies in the development of a procedure for obtaining a suitable carbon adsorbent, whose properties are consistent with the properties of the adsorbate. An appropriate activation was used, allowing the preparation of an adsorbent with a highly developed porous texture and a large surface area, which is a prerequisite for a significant adsorption capacity of the obtained adsorbents towards PFOA. Both carbon adsorbents obtained from peach pits, with clearly different surface chemistry—KOH-activated carbon (AC_KOH) and its nitric acid-oxidized derivative (AC_HNO3)—for PFOA adsorption were compared, along with the clarification of the relationship between the graphitic structure, pore development, surface functionality and adsorption characteristics. The first adsorbent was produced by chemical activation with KOH at 800 °C, while the second was obtained by oxidative modification of the activated sample with 12% HNO₃. Characterization by Raman spectroscopy, SEM, and nitrogen physisorption revealed a highly graphitized structure (ID/IG = 0.86) and well-developed porosity. Adsorption experiments were carried out at PFOA concentrations from 8 to 40 µmol/L using a spectrophotometric method based on methylene blue ion-pair extraction into chloroform. The results showed that AC_KOH exhibited a high maximum adsorption capacity of 1660 µmol/g (687.36 mg/g) and followed the Langmuir isotherm model, indicating monolayer adsorption. In contrast, AC_HNO3 showed a significantly lower adsorption capacity of 398.36 µmol/g (164.95 mg/g), which was attributed to electrostatic repulsion caused by acidic oxygen-containing surface groups. These findings demonstrate that peach stone-derived activated carbon is a promising, sustainable, and efficient adsorbent for the removal of PFOA from water. Full article

Kavalactones are psychoactive substances that naturally occur in some plants, such as Piper methysticum, Alpinia zerumbet, and Achyrocline satureioides, which are considered to have a significantly positive effect on human organisms. For example, Alpinia zerumbet is classified as a life-expanding plant. Although high-pressure liquid chromatography–mass spectrometry has been used for kavalactone analysis in plant material, the fragmentation pathways of protonated kavalactone molecules are not fully known and require further detailed study. In this paper, the fragmentation pathways of [M+H]⁺ ions of twelve kavalactones, including three pairs of isomers, are discussed in detail. Special emphasis has been placed on diagnostic product ions, which are characteristic of kavalactone structures. It has been demonstrated that diagnostic ions and structure–fragmentation relationships enable the differentiation of isomeric kavalactones and may be useful for the identification of other kavalactone conjugates, such as kavalactone dimers or kavalactone glycosides. Full article

Silicon carbide (SiC) detectors continue to emerge as a promising technology for applications requiring radiation hardness, fast response times, and stable operation in harsh environments. In this work, the charge-collection dynamics of ultra-thin membrane SiC detectors are investigated through time-dependent TCAD simulations, consistent with previously reported measurements. The study analyzes the transient response following the localized generation of electron–hole pairs induced by ions, comparing bulk and membrane detector geometries with identical active-layer thicknesses. Two-dimensional simulations provide a time-resolved characterization of the electron and hole current-density distributions within the active region of the device. The results show that both device architectures present a transient current signal featuring two main components. Despite similarities in the prompt drift-driven signal component, the SiC membrane response is characterized by a short secondary component returning to zero within 3.5 × 10^–10 s at zero external bias, making it well-suited for reliable single-ion detection. In contrast, bulk devices exhibit a markedly different response, characterized by a significantly more intense and prolonged secondary component followed by a long tail that does not return to zero within the simulation time window for all investigated reverse biases. This tail is the result of the collection of carriers generated in the substrate that reach the depletion region through diffusion-driven processes. These findings contribute to the optimization of SiC-based solid-state detectors for quantum-technology device fabrication, demonstrating that the removal of the substrate drastically reduces the diffusion-dominated current component, thereby ensuring precise timing and minimal charge loss. Full article

Potassium-ion batteries hold great promise for large-scale energy storage, but their commercialization is hindered by the large ionic radius of potassium, which causes sluggish kinetics and severe volume expansion in anode materials. To address this, we present a scalable spray-drying strategy coupled with NaCl salt-templating to synthesize hierarchical porous carbon/vanadium sulfide microspheres (p-V₃S₄/C MS). In this structure, V₃S₄ nanoparticles are uniformly encapsulated within a dextrin-derived amorphous carbon matrix, and pores are formed via selective NaCl etching. This unique architecture accommodates volume fluctuations while providing rapid ion diffusion pathways. As a result, the p-V₃S₄/C MS anode exhibits outstanding electrochemical performance, maintaining a reversible capacity of 107 mA h g⁻¹ after 2000 cycles at 2.0 A g⁻¹, and achieves a high pseudocapacitive contribution of 93% at 2.0 mV s⁻¹. Furthermore, a full cell paired with a Prussian blue (PB) cathode demonstrates practical viability and robust reversibility. Our findings demonstrate that this structural engineering effectively mitigates internal resistance and structural degradation, offering a cost-effective route for mass-producing high-performance anodes for next-generation energy storage. Full article

In conventional low-viscosity solvents, magnetic field effects (MFEs) in photoredox catalysis are often negligible because photogenerated radical ion pairs (RIPs) diffuse apart before significant spin evolution occurs. This study reports using ionic liquids (ILs) as a tunable homogeneous “solvent cage” to observe distinct low-field MFEs in the phenothiazine-mediated photoinduced reductive dechlorination of aryl chlorides. Experimental results demonstrate that MFEs increase significantly with bulk viscosity, reaching saturation at approximately 1000 Gs with a maximum enhancement of about 15%, consistent with the hyperfine coupling mechanism (HFCM). Femtosecond transient absorption spectroscopy (fs-TA) reveals that the ionic liquid environment effectively reduces the radical cage escape rate, matching it with the spin evolution rate. This allows the external magnetic field to intervene in the back electron transfer (BET) process. However, unlike strongly confined micellar systems, the contribution of the triplet charge recombination (TCR) pathway here is moderate, intrinsically limiting the magnetic enhancement amplitude. These findings establish that MFE magnitude is determined by both viscosity-controlled cage dynamics and the efficiency of the TCR channel, providing a mechanistic basis for designing spin-modulated homogeneous photoredox systems. Full article

Recent advances in energy storage systems and in increasingly efficient, safe, and energy-dense cell chemistries have driven the need for commercial Battery Management System (BMS) architectures with greater control, data acquisition, and communication capabilities, primarily oriented towards customization. This demand introduces a significant change in how electrical systems are modeled and simulated when they integrate active electrochemical elements such as lithium-ion cells. This work presents the development and modeling of a BMS for critical and high-efficiency applications, based on active balancing techniques and incorporating an additional safety stage to respond to failures when charging ${\mathrm{LiFePO}}_4$ cells. The electrochemical model was built using an equivalent RLC circuit and RC pairs to represent the Thevenin response of the cell. For the simulation of active balancers, LTspice was employed, while charging and discharging processes and their effects on state of charge (SOC) and state of health (SOH) were complemented through analysis in MATLAB R2024a.The proposed approach offers an efficient tool for evaluating cell dynamics and validating battery management strategies in demanding scenarios. While the current approach prioritizes the individual modeling of electrical conversion systems, our framework presents an innovative multisystem macromodel, where not only is the electrical behavior simulated but also the control, efficiency, and safety of the system are determined, prioritizing reproducibility through SPICE tools. Full article

Due to its affordability, widespread availability, non-toxicity, biodegradability, and renewability, cellulose is considered a crucial material for addressing the depletion of petroleum resources. In this study, a rotaxane-based supramolecular polymer derived from thermoplastic polyurethane (TPU) was synthesized and combined with cellulose to create a TPU–cellulose composite (TPU-C). This composite was employed as a separator for acrylate-based quasi-solid polymer electrolytes (QPEs). The polymer electrolyte demonstrated a high ionic conductivity of 0.16 mS cm⁻¹ at room temperature, a lithium-ion transference number of 0.63, and an electrochemical stability window extending up to 4.7 V. When paired with a LiFePO₄ (LFP) cathode, the coin cell retained 88.8% of its capacity after 100 cycles at 1 C. A cell assembled with Li and a high-voltage NCM622 cathode maintained a capacity of 65.8% after 100 cycles at 0.3 C. Additionally, the excellent electrochemical performance was analyzed through density functional theory (DFT) calculations to identify the underlying reasons for its outstanding behavior. This study offers new insights into expanding the application potential of cellulose-based composite materials. Full article