Search Results (7,948)

Background: Ferrabis(dicarbollide) ([o-FESAN]⁻) in combination with proton–boron fusion therapy (PBFT) or boron neutron capture therapy (BNCT) are promising alternative radiation modalities for the treatment of breast cancer. The aim of this study was to explore the underlying effects of [o-FESAN]⁻ radio enhancement on breast cancer cells in vitro and in vivo, and to perform comparative dosimetry calculations. Methods: The cellular effects on SKBR-3 and MDA-MB-231 breast cancer cells and MDA-MB-231 xenograft-bearing nude mice induced by carrier-free [o-FESAN]⁻ after BNCT or PBFT were evaluated following recommended protocols. Monte Carlo (MC) dosimetry calculations were performed at the cellular scale for both radiation modalities. Results: Selective retention of [o-FESAN]⁻ within the cytoplasm and nucleus of SKBR-3 and MDA-MB-231 breast cancer cells is demonstrated. Moreover, in vivo studies with MDA-MB-231 xenograft-bearing nude mice show appreciable accumulation of [o-FESAN]⁻ in the tumor. Both radiation modalities induce loss of cellular viability and survival. Comparative dosimetry studies between proton and neutron irradiation agree with the viability data, showing a good correlation between absorbed dose vs. cellular effects. In the case of PBFT, cell structural changes are likely due to necrosis caused by the production of reactive oxygen species (ROS). To explain the radio enhancement effects in more detail, other mechanisms should be taken into consideration. Conclusions: Our results validate the effectiveness of both PBFT and BNCT therapeutic modalities, warranting further studies on carrier-free [o-FESAN]⁻ as a candidate drug for potential clinical translation of radio enhancers in binary radiation therapies. Full article

Understanding how solvents influence the luminescence behavior of Cu(I) complexes is crucial for designing advanced optical sensors. This study reports the synthesis, structures and photophysical investigation of an 8-hydroxyquinoline-functionalized 1H-imidazo[4,5-f][1,10]phenanthroline ligand, ipqH₂, and its four Cu(I) complexes with diphosphine co-ligands. Photoluminescence studies demonstrated distinct solvent-dependent excited-state mechanisms. In DMSO/alcohol mixtures, free ipqH₂ exhibited excited-state proton transfer (ESPT) and enol-keto tautomerization, producing dual emission at about 447 and 560 nm, while the complexes resisted ESPT due to hydrogen bond blocking by PF₆⁻ anions and Cu(I) coordination. In DMSO/H₂O, aggregation-caused quenching (ACQ) and high-energy O–H vibrational quenching dominated, but complexes 1 and 2 showed a significant red-shifted emission (569–574 nm) with high water content due to solvent-stabilized intra-ligand charge transfer and metal-to-ligand charge transfer ((IL+ML)CT) states. In DMSO/DMF, hydrogen bond competition and solvation-shell reorganization led to distinct responses: complexes 1 and 3, with flexible bis[(2-diphenylphosphino)phenyl]ether (POP) ligands, displayed peak splitting and (IL + ML)CT redshift emission (501 ⟶ 530 nm), whereas complexes 2 and 4, with rigid 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos), showed weaker responses. The flexibility of the diphosphine ligand dictated DMF sensitivity, while the coordination, the hydrogen bonds between PF₆⁻ anions and ipqH₂, and water solubility governed the alcohol/water responses. This work elucidates the multifaceted solvent-responsive mechanisms in Cu(I) complexes, facilitating the design of solvent-discriminative luminescent sensors. Full article

Objective: This study aimed to compare the effectiveness and safety of vonoprazan–amoxicillin (VA) dual therapy with modified bismuth-containing quadruple therapy (esomeprazole, bismuth, amoxicillin, and clarithromycin; EBAC) in treatment-naïve patients infected with Helicobacter pylori (H. pylori). Methods: In this single-center, open-label, randomized controlled trial conducted from July to December 2024, a total of 504 H. pylori-positive patients were randomly allocated to receive either VA (vonoprazan 20 mg and amoxicillin 1000 mg, twice daily for 14 days) or EBAC (esomeprazole 20 mg bid, bismuth potassium citrate 220 mg bid, amoxicillin 1000 mg bid, clarithromycin 500 mg bid, twice daily for 14 days). The primary endpoint was the H. pylori eradication rate, and the secondary endpoint was safety. Results: In the intention-to-treat (ITT) analysis, the eradication rates were 79.4% (200/252) in the VA group and 85.7% (216/252) in the EBAC group (p = 0.060). Per-protocol (PP) analysis showed comparable eradication rates between the two groups (92.1% [197/214] vs. 93.0% [213/229], p = 0.712), confirming the non-inferiority of VA compared to EBAC. The incidence of adverse events was significantly fewer in the VA group (27.2% vs. 42.7%, p < 0.001). Logistic regression identified medication adherence (≥80%) as the only independent predictor of successful eradication (OR 17.557, p < 0.001). Conclusion: VA dual therapy achieved comparable H. pylori eradication rates to EBAC, while offering better safety and a more convenient regimen, supporting it as a preferred first-line treatment for H. pylori infection. Full article

Microbial electrolysis cells (MECs) present a viable platform for sustainable hydrogen generation from organic waste, but their scalability is limited by cathode performance, cost, and durability. This study evaluates three hybrid carbon nanotube (CNT) cathodes—acid-washed CNT (AW-CNT), thin layer non-acid-washed CNT (TN-NAW-CNT), and thick layer non-acid-washed CNT (TK-NAW-CNT)—each composed of stainless-steel-supported CNTs coated with molybdenum phosphide (MoP). These were benchmarked against woven carbon cloth (WCC) under varied operational conditions. A custom multi-channel reactor operated for 341 days, testing cathode performance across applied voltages (0.7–1.2 V), buffer types (phosphate vs. bicarbonate), pH (7.0 and 8.5), buffer concentrations (10–200 mM), and substrates including acetate, lactate, and treated acid whey. CNT-based cathodes consistently showed higher current densities than WCC across most conditions with significant difference found at higher applied voltages. TK-NAW-CNT achieved peak current densities of 259 A m⁻² at 1.2 V and maintained >41 A m⁻² in real-waste conditions with no added buffer. Long-term performance losses were minimal: 4.5% (TN-NAW-CNT), 0.1% (TK-NAW-CNT), 10.8% (AW-CNT), and 6.8% (WCC). CNT cathodes showed improved performance from reduced resistance and greater electrochemical stability, while proton transfer improvements benefited all materials due to buffer type and pH conditions. These results highlight CNT-based cathodes as promising, scalable alternatives to WCC for energy-positive wastewater treatment. Full article

This work focuses on the origin of electrons, Compton photons and a gravitational field. Based on the discovered 10D Planck units, the physical behavior of these units was further studied in isolated systems. Investigation shows that a 10D Planck unit in the in situ state has the same properties as a stationary electron, while its non-in situ state shares the same physics with a Compton photon. Results indicate that photons’ potential exists between any two Compton photons, with their strength being determined by the distance between the two photons. Finally, the potential field was proved to be the gravitational field of a proton. Full article

Experimental measurement of dose distributions is a pivotal step in the quality assurance of radiotherapy treatments, especially for those relying on high delivery accuracy such as hadron therapy. This study investigated the response of a polymer gel dosimeter to determine its suitability in performing geometric beam characterizations for hadron therapy under high-quenching conditions. Different extraction energies of proton and carbon ion beams were considered. Gel dose–response linearity and long-term stability were confirmed through optical measurements. Gel phantoms were irradiated with pencil beams and analyzed via magnetic resonance imaging. A multi-echo T₂-weighted sequence was used to reconstruct depth–dose profiles and transversal distributions acquired by the gels, which were benchmarked against reference data. As expected, a response-quenching effect in the Bragg peak region was noted. Nonetheless, the studied gel formulation proved reliable in acquiring the geometric characteristics of the beams, even without correcting for the quenching effect. Indeed, depth–dose distributions acquired by the gels showed an excellent agreement with measured particle range with respect to reference values, with mean discrepancies of 0.5 ± 0.2 mm. Single-spot transverse FWHM values at increasing depths also presented an average agreement within 1 mm with values determined with radiochromic films, thus supporting the excellent spatial resolving capabilities of the dosimetric gel. Full article

We investigate the quantum dynamics of coherence in the hyperfine structure of hydrogen atoms subjected to dephasing noise, modeled using the Lindblad master equation. The effective Hamiltonian describes the spin–spin interaction between the electron and proton, with dephasing introduced via Lindblad operators. Analytical solutions for the time-dependent density matrix are derived for various initial states, including separable, partially entangled, and maximally entangled configurations. Quantum coherence is quantified through the $l_1$-norm measures, while purity is evaluated to assess mixedness. Results demonstrate that coherence exhibits oscillatory decay modulated by the dephasing rate, with antiparallel spin states showing greater resilience against noise compared to parallel configurations. These findings highlight the interplay between coherent hyperfine dynamics and environmental dephasing, offering insights into preserving quantum resources in atomic systems for applications in quantum information science. Full article

Vincristine is a classical chemotherapeutic agent widely used for its ability to disrupt microtubule polymerization, yet additional molecular effects may contribute to its anticancer activity. G-quadruplexes (G4s), non-canonical nucleic acid structures enriched in regulatory regions of the genome and in mitochondrial DNA, have emerged as relevant modulators of cellular homeostasis. In this study, we investigated whether vincristine can influence G4 biology. Cancer cells treated with vincristine were analyzed by immunofluorescence, revealing a consistent increase in nuclear and mitochondrial G4 foci. In particular, mitochondrial G4s were significantly elevated by approximately 1.5–2.5 fold compared to untreated cells, an effect accompanied by a detectable reduction in membrane potential, indicative of impaired organelle function. In addition, biophysical analyses on representative G4-forming sequences were carried out. Proton nuclear magnetic resonance titrations showed localized chemical shift perturbations upon vincristine addition, circular dichroism confirmed preservation of G4 topology, and isothermal titration calorimetry indicated weak but enthalpically favorable interactions. Taken together, these results suggest that vincristine perturbs both the cellular G4 landscape and mitochondrial homeostasis, while also engaging G4 DNA in vitro. Although additional studies are required to establish the mechanistic details, this work provides proof-of-concept for a previously unrecognized dimension of vincristine’s anticancer action. Full article

The voltage-gated proton channel (H_v1) selectively transports protons (H⁺) across biological membranes in response to membrane potential changes. H_v1 is assembled as a dimer, and unlike most voltage-gated ion channels, it lacks a traditional central pore domain; instead, the voltage-sensing domain (VSD) of each monomer facilitates proton conduction via a hydrogen-bond network. H_v1 is widely expressed in various human cell types (e.g., immune cells, sperm, etc.) including tumor cells. In tumor cells, the accumulation of acidic intermediates generated by glycolysis under hypoxic conditions or ROS production leads to significant cytosolic acidification. H_v1 can remove protons from the cytosol rapidly, contributing to the adaptation of the cells to the tumor microenvironment, which may have significant consequences in tumor cell survival, proliferation, and progression. Therefore, H_v1 may be very promising not only as a tumor marker but also as a potential therapeutic target in oncology. Molecules that modulate the proton flux through H_v1 can be divided into two broad groups: inhibitors and activators. H_v1 inhibitors can be simple ions, small molecules, lipids, and peptides. In contrast, fewer H_v1 activators are known, including albumin, NH29, quercetin, and arachidonic acid. The mechanism of action of some inhibitors is well described, but not all. H_v1 modulation has profound effects on cellular physiology, especially under stress or pathological conditions, like cancer and inflammation. The therapeutic application of selective H_v1 inhibitors or activators could be a very promising strategy in the treatment of several serious diseases. Full article

A new sensor system for the determination of nitrogen-containing pharmaceutical substances has been proposed. It is based on the use of an ion association complex formed between cationic polyacrylamide (CPAA) and sulfonephthalein dye as a reagent. Bromocresol purple (BCP) interacts with CPAA to form a complex through hydrophobic interaction as well as electrostatic interaction. In the pH range from 3.5 to 5.5, this leads to an increase in the intensity of the dianionic form BCP band at 590 nm. The interaction between the polymer and the dye leads to an increase in the acidic properties of BCP, causing its pK_a2 to shift from 6.3 to 3.75. Subsequently, when loratadine (LOR) is added to the CPAA/BCP system, the strong electrostatic interaction between the BCP monoanion and the protonated form of LOR leads to a decrease in the intensity of the band at 590 nm and an increase in the absorbance of the band at 432 nm, which is related to the dye monoanion. Here, we have demonstrated that this facile methodology can enable the rapid, reliable, and selective determination of LOR with a detection limit of 1.6 mg L⁻¹ and a linear range from 5.0 to 120 mg L⁻¹. The environmental friendliness of the developed method was assessed using the AGREE metric and is characterized by a high score of 0.83. The developed method represents a new approach to the creation of extraction-free spectrophotometric methods based on ionic associates of anionic dyes with protonated forms of nitrogen-containing medicinal compounds. The method was successfully applied to the determination of LOR in pharmaceutical preparations with satisfactory precision and accuracy. Overall, the results obtained indicate that this method has great potential for application in pharmaceutical analysis. Full article

The control of crystal form in chiral active pharmaceutical ingredients (APIs) is a critical challenge in pharmaceutical development, as differences in solid-state structure can significantly influence physical properties and manufacturing performance. Troglitazone, a molecule with two chiral centers, exists as four stereoisomers (RR, SS, RS, SR) that crystallize as two enantiomeric pairs: RR/SS and RS/SR. This study aims to elucidate the relationship between solution-state molecular interactions and crystallization behavior of these diastereomeric pairs. Antisolvent crystallization experiments were conducted for both mixed solutions containing all four isomers and solutions of individual pairs. Crystallization kinetics were monitored by HPLC, and the resulting solids were characterized by PXRD, DSC, TG, and microscopic observation. Nucleation induction times were determined over a range of supersaturation levels. To probe intermolecular interactions in solution, NOESY and targeted NOE NMR experiments were performed, and the results were compared with crystallographic data. The RS/SR crystals(H-form) consistently exhibited shorter induction times and faster crystallization rates than the RR/SS crystals (L-form), even under conditions where RR/SS solutions were more supersaturated. In mixed solutions, H-form crystallized preferentially, with L-form either remaining in solution or being incorporated into H-form crystals as a solid solution. NOESY and NOE analyses revealed intermolecular proximities between protons that are distant in the molecular structure, indicating the presence of ordered aggregates in solution. These aggregates were more structurally compatible with the H-form than with the L-form crystal lattice, as supported by crystallographic distance analysis. The results demonstrate that differences in nucleation kinetics between troglitazone diastereomers are closely linked to solution-state molecular arrangements. Understanding these relationships provides a molecular-level basis for the rational design of selective crystallization processes for chiral APIs. Full article

In this article, the mechanism of relaxation polarization currents occurring at a constant temperature (isothermal process) in crystals with ionic-molecular chemical bonds (CIMBs) in an alternating electric field was investigated. Methods of the quasi-classical kinetic theory of dielectric relaxation, based on solutions of the nonlinear system of Fokker–Planck and Poisson equations (for the blocking electrode model) and perturbation theory (by expanding into an infinite series in powers of a dimensionless small parameter) were used. Generalized nonlinear mathematical expressions for calculating the complex amplitudes of relaxation modes of the volume-charge distribution of the main charge carriers (ions, protons, water molecules, etc.) were obtained. On this basis, formulas for the current density of relaxation polarization (for transient processes in a dielectric) in the k-th approximation of perturbation theory were constructed. The isothermal polarization currents are investigated in detail in the first four approximations (k = 1, 2, 3, 4) of perturbation theory. These expressions will be applied in the future to compare the results of theory and experiment, in analytical studies of the kinetics of isothermal ion-relaxation (in crystals with hydrogen bonds (HBC), proton-relaxation) polarization and in calculating the parameters of relaxers (molecular characteristics of charge carriers and crystal lattice parameters) in a wide range of field parameters (0.1–1000 MV/m) and temperatures (1–1550 K). Asymptotic (far from transient processes) recurrent formulas are constructed for complex amplitudes of relaxation modes and for the polarization current density in an arbitrary approximation k of perturbation theory with a multiplicity r by the polarizing field (a multiple of the fundamental frequency of the field). The high degree of reliability of the theoretical results obtained is justified by the complete agreement of the equations of the mathematical model for transient and stationary processes in the system with a harmonic external disturbance. This work is of a theoretical nature and is focused on the construction and analysis of nonlinear properties of a physical and mathematical model of isothermal ion-relaxation polarization in CIMB crystals under various parameters of electrical and temperature effects. The theoretical foundations for research (construction of equations and working formulas, algorithms, and computer programs for numerical calculations) of nonlinear kinetic phenomena during thermally stimulated relaxation polarization have been laid. This allows, with a higher degree of resolution of measuring instruments, to reveal the physical mechanisms of dielectric relaxation and conductivity and to calculate the parameters of a wide class of relaxators in dielectrics in a wide experimental temperature range (25–550 K). Full article

The mudflat crab (H. tientsinensis) is a dominant species in coastal tidal flat areas, primarily inhabiting the high tide region of the intertidal zone, and possesses significant ecological and economic value. Vibrio species are one of the main bacterial pathogens responsible for diseases in marine organisms, and they are widely distributed in seawater and estuarine environments. However, the immune mechanisms employed by H. tientsinensis in response to Vibrio infections remain unclear. This study aims to investigate the physiological and immune mechanisms by analyzing the structural changes and differential gene expression in the gill and hepatopancreas following Vibrio parahaemolyticus infection. The results indicate that V. parahaemolyticus infection causes cellular damage, with structural alterations observed in the gills (epithelial cell edema in the gill filaments, and aneurysm formation) and the hepatopancreas (changes in lumen size, nuclear condensation, and modifications in connective tissue morphology). Transcriptome analysis revealed 9766 differentially expressed genes (DEGs) in the gills of the experimental group, with 4687 upregulated and 5079 downregulated genes. These DEGs are primarily involved in different ribosomal subunits. In the hepatopancreas, 1594 DEGs were identified, with 834 upregulated and 760 downregulated. These DEGs are predominantly associated with energy-coupled proton transmembrane transport, electron transport-coupled proton transport, and lipid transporter activity. H. tientsinensis gene annotation and KEGG enrichment analysis revealed that chemical carcinogens DNA adducts, amino acid metabolism, and some immune pathways play key roles in the ability of H. tientsinensis to defend against V. parahaemolyticus infection. The findings of this study contribute to a deeper understanding of the immune mechanisms of H. tientsinensis against V. parahaemolyticus infection and provide new insights for aquaculture management. Full article

Background/Objectives: Black hairy tongue syndrome (BHT) is characterized by structural epithelial changes and a dark discoloration on the surface of the tongue, causing a variety of symptoms such as xerostomia, altered taste, and nausea. Methods: Herein, we report a 70-year-old female patient with a history of Sjogren’s syndrome, rheumatoid arthritis, and occasional use of intranasal and inhaled corticosteroids, who presented with BHT exacerbated by consumption of colored beverages and carbohydrates. We also provide a review of the literature on published articles reporting cases of BHT syndrome. Results: Our patient’s condition improved after implementing dietary restrictions in combination with local care. A literature review revealed that the most common reported exposures and underlying conditions in patients with BHT were the recent administration of antibiotics, solid organ or hematologic malignancy, immunosuppressants, smoking, corticosteroids, autoimmune conditions, receipt of antidepressants, local radiation therapy, proton pump inhibitors, and alcohol. The majority of cases were successfully managed with the elimination of implicated factors when possible and local hygiene. Conclusions: Different factors may contribute to the development of BHT. Discontinuation of implicated medications together with measures for topical care constitute the most effective ways to achieve resolution. Full article

This work explores the integration of Proton Exchange Membrane (PEM) electrolysis waste heat with district heating networks (DHN), aiming to enhance the overall energy efficiency and economic viability of hydrogen production systems. PEM electrolysers generate substantial amounts of low-temperature waste heat during operation, which is often dissipated and left unutilised. By recovering such thermal energy and selling it to district heating systems, a synergistic energy pathway that supports both green hydrogen production and sustainable urban heating can be achieved. The study investigates how the electrolyser’s operating temperature, ranging between 50 and 80 °C, influences both hydrogen production and thermal energy availability, exploring trade-offs between electrical efficiency and heat recovery potential. Furthermore, the study evaluates the compatibility of the recovered heat with common heat emission systems such as radiators, fan coils, and radiant floors. Results indicate that valorising waste heat can enhance the overall system performance by reducing the electrolyser’s specific energy consumption and its levelized cost of hydrogen (LCOH) while supplying carbon-free thermal energy for the end users. This integrated approach contributes to the broader goal of sector coupling, offering a pathway toward more resilient, flexible, and resource-efficient energy systems. Full article