Search Results (4,467)

Single crystals of the layered EuRECuTe₃ series with RE = Nd, Sm, Tb and Dy are obtained for the first time, completing the series of studies on quaternary tellurides synthesized using the halide flux method. These compounds crystallize in the orthorhombic space group Pnma (no. 62) with unit cell parameters ranging from a = 11.5634(7) Å, b = 4.3792(3) Å and c = 14.3781(9) Å for EuNdCuTe₃ to a = 11.2695(7) Å, b = 4.3178(3) Å and c = 14.3304(9) Å for EuDyCuTe₃. The influence of prismatic polyhedra [EuTe₆₊₁]⁷⁻ structural units on the stabilization of 3d framework composed by 2d layered fragments [RECuTe₃]²⁻, which have a key role in the interlayer interaction, is established. A comparative analysis of structural and magnetic properties dependence on the rare-earth element radius r_i(RE³⁺) in the EuRECuTe₃ series (RE = Sc, Y, Nd–Lu) is carried out. The structural contraction, including decrease in degree of tetrahedral polyhedra distortion, bond lengths shortening and unit cell volume shrinking with increasing r_i(RE³⁺), is established. It is shown that the structural alternation leads to transition from ferromagnetic to ferrimagnetic ordering. It was established that changes in the cationic sublattice have a more significant impact on structural transitions in the series of quaternary tellurides than changes in the anionic sublattice. The electronic structure and elastic and dynamic properties were estimated using ab initio calculations. The exfoliation energy for each compound is obtained by estimation of monolayer ground state energy as a result of structure relaxation. The symmetry and structural properties of monolayer EuRECuTe₃ (RE = Nd, Sm, Tb, Dy) compound are established and the orthorhombic symmetry is obtained with layer group pm2_1b. Full article

In exerting its actions on the utilization and storage of nutrients, the hormonal effects of insulin (INS) on target cells include important changes in terms of cell morphology involving cytoskeletal actin. Sensitivity to INS affects intestinal epithelial cells, which express receptors through which tight junctions and barrier permeability are also modulated. Nevertheless, the impact of INS on physiological rather than pathophysiological processes along gastrointestinal epithelia is not fully established. Here, we investigate INS effects on differentiated Caco-2 monolayers challenged by inflammatory stimuli, i.e., interleukin 1 beta (IL-1β) and interferon gamma (IFN-γ), aiming to identify morpho-functional variations potentially associated with INS-dependent responses in intestinal epithelia differentially driven by different inflammation mediators. By observing the actin cytoskeleton, we characterized the impact of INS on actin structures’ organization, both in the absence and presence of pro-inflammatory treatments. Coherently, we observed altered expression of proteins interrelated to cytoskeletal dynamics (FAK, ITGB1), particularly evident in the synergistic action of IFN-γ and INS, also confirmed by the impact on INS-mediated regulation of the MAPK signalling pathway. Overall, the results describe a modular responsiveness of enterocyte-like monolayers to INS, depending on different inflammatory mediators, hinting at the interplay between INS signalling and morpho-functional remodelling in intestinal epithelial cells. Full article

In this study, we isolated and identified six major phenolic constituents from Cephalaria uralensis. The compounds—quercetin 6-C-β-glucopyranoside, isoorientin, swertiajaponin, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, and chlorogenic acid—were characterized by LC–MS and NMR. All isolates exhibited strong free-radical scavenging ability and significant interaction with lipid monolayers (Δπ up to ~6.5–7 mN/m), suggesting dual antioxidant and membrane-perturbing activities. In antioxidant assays, isoorientin, showed the lowest IC₅₀ among the isolates. Notably, 4,5-dicaffeoylquinic acid caused the largest increase in monolayer surface pressure, indicating a particularly strong tendency to integrate with lipid bilayers. In fact, chlorogenic acid, isoorientin, and swertiajaponin are well-documented natural antioxidants, and related phenolic acids have been shown to possess potent antimicrobial activity. Thus, the C. uralensis phenolics identified in our study likely underlie the extract’s bioactivity. These findings highlight C. uralensis as a source of membrane-active polyphenols with potential applications in skin-related oxidative and microbial conditions. Full article

Postmenopausal osteoporosis (PMOP) has become an important public health issue. The diagnosis of PMOP relies on clinical symptoms and radiology. However, most patients with PMOP do not exhibit obvious symptoms in the early stages of this disease. This study aimed to explore the feasibility of surface-enhanced Raman scattering (SERS) technology in the auxiliary screening of PMOP. PMOP rats were induced by ovariectomy (OVX) surgery, with a Sham group and an icariin (ICA) treatment group serving as controls. A monolayer film of Au nanoparticles (NPs) was prepared using the Marangoni effect in an oil/water/oil three-phase system, and was used to detect serum SERS signals in the Sham, OVX, and ICA treatment groups. Then, the spectral diagnostic model for PMOP screening was established utilizing partial least squares (PLS) and support vector machine (SVM) algorithms. Histopathology confirmed the establishment of the PMOP rat model. The assignment of Raman peaks and the analysis of spectral differences revealed the biochemical changes associated with PMOP, including the upregulation of tyrosine levels and the downregulation of arginine, tryptophan, lipids, and collagen. When employing the PLS-SVM algorithm to simultaneously classify and discriminate three groups of samples, the diagnostic sensitivity for PMOP is 93.33%, the specificity is 96.67%, and the accuracy of three-class classification is 91.11%. This study demonstrated the potential of SERS for the auxiliary screening of PMOP. Full article

The aim of this study was to investigate the metabolites in Aspergillus subramanianii 1901NT-1.40.2 extract using UPLC-MS, isolate and elucidate the structure of individual compounds, and study the antimicrobial and cytotoxic activities of the isolated compounds. The structures of two previously unreported ergostane triterpenoid aspersubrin A (1) and pyrazine alkaloid ochramide E (2) were established using NMR and HR ESI-MS. The absolute configuration of 1 was determined using quantum chemical calculations. Moreover, the known polyketides sclerolide (3) and sclerin (4); the indolediterpene alkaloid 10,23-dihydro-24,25-dehydroaflavinine (5); the bis-indolyl benzenoid alkaloids kumbicin D (6), asterriquinol D dimethyl ether (7), petromurin C (8); and the cyclopentenedione asterredione (9) were isolated. The effects of compounds 3-9 on the growth and biofilm formation of the yeast-like fungus Candida albicans and the bacteria Staphylococcus aureus and Escherichia coli were investigated. Compounds 5 and 6 inhibited C. albicans growth and biofilm formation at an IC₅₀ of 7–10 µM. Moreover, the effects of compounds 3-9 on non-cancerous H9c2 cardiomyocytes, HaCaT keratinocytes, MCF-10A breast epithelial cells, and breast cancer MCF-7 and MDA-MB-231 cells were also investigated. Compound 8 (10 µM) significantly decreased the viability of MCF-7 cells, inhibited colony formation, and arrested cell cycle progression and proliferation in monolayer culture. Moreover, 8 significantly decreased the area of MCF-7 3D spheroids by approximately 30%. A competitive test with 4-hydroxytamoxyfen and molecular docking showed that estrogen receptors (ERβ more than ERα) were involved in the anticancer effect of petromurin C (8). Full article

Background: Predicting oral drug absorption in humans is critical during early drug development. Current in vitro systems to predict absorption (e.g., PAMPA and MDCK cells) are lacking for certain classes of drugs. Intestinal organoids are emerging as a promising alternative that offers several potential advantages. In this study, we utilized human intestinal organoid-derived monolayers to predict oral absorption of lenalidomide. Methods: Human jejunal organoids (RepliGut^®) were cultured as monolayers on transwell plates and differentiated into intestinal epithelial cells. Lenalidomide permeability in the organoid system was compared with the permeability in the conventional Madin-Darby Canine Kidney cell (MDCK) monolayer system, as well as P-gp knockout, human P-gp overexpressing, and human BCRP overexpressing MDCK cells across a concentration range of 1 to 500 µM. Male Sprague Dawley rats were administered lenalidomide orally/intravenously, and concentrations in the serum, urine, and feces were measured and modeled in Phoenix WinNonlin. Results: Orally administered lenalidomide was well absorbed by rats at all doses (bioavailability = 68–120%). In the human jejunal organoid model, lenalidomide apparent permeability (Papp) was approximately 0.6 × 10⁻⁶ cm/s independent of the concentration used (1–500 µM). In contrast, lenalidomide Papp was significantly lower in gMDCK cell monolayers, approximately 0.2 × 10⁻⁶ cm/s. Additionally, lenalidomide was identified as a P-gp/BCRP substrate in intestinal organoids and gMDCK P-gp and BCRP overexpressing cells. Conclusions: Lenalidomide Papp was significantly lower in gMDCK monolayers than expected based on its high bioavailability. Our results suggest that organoid systems can better capture transporter and paracellularly mediated effects on drug permeability, which may allow for more accurate predictions of in vivo absorption. Full article

The electronic and magnetic properties of lanthanide-doped GaN monolayers (Ln = La, Pr, Nd, Pm, Eu, and Gd) have been systematically investigated using density functional theory within the GGA-PBE approximation. Our results demonstrate that all Ln dopants except La introduce spin polarization and half-semiconductor behavior into the GaN monolayer. The observed magnetism primarily arises from unpaired 4f electrons, yielding magnetic moments of 2.0, 3.0, 4.0, 6.0, and 7.0 μ_B for Pr, Nd, Pm, Eu, and Gd, respectively. While La-, Pr-, and Gd-doped systems retain the indirect band gap characteristic of pristine GaN, an indirect-to-direct band gap transition occurs under biaxial tensile strains exceeding 2%. In contrast, Nd, Pm, and Eu doping directly induce a direct band gap without applied strain. Notably, under 6% tensile strain, the Pm- and Eu-GaN systems exhibit half-metallic and metallic properties, respectively. These tunable electronic and magnetic properties suggest that Ln doping offers a promising strategy for designing functional two-dimensional GaN-based electronic and spintronic devices. Full article

Inverted (p-i-n) CsPbI_xBr_3−x (x = 0~3) perovskite solar cells (PSCs) are of growing interest due to their excellent thermal stability and optoelectronic performance. However, they suffer from severe energy level mismatch and significant interfacial energy losses at the bottom hole transport layers (HTLs). Herein, we propose a strategy to simultaneously enhance the crystallinity of CsPbI_2.85Br_0.15 and facilitate hole extraction at the HTL/CsPbI_2.85Br_0.15 interface by incorporating semiconducting single-walled carbon nanotubes (SWCNTs) onto [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl] phosphonic acid (MeO-2PACz) HTL. The unique electrical properties of SWCNTs enable the MeO-2PACz/SWCNT HTL to achieve high conductivity, optimal energy level alignment, and an adaptable surface. Consequently, the defect density is reduced, hole extraction is accelerated, and interfacial charge recombination is effectively suppressed. As a result, these synergistic benefits boost the power conversion efficiency (PCE) from 15.74% to 18.78%. Moreover, unencapsulated devices retained 92.35% of their initial PCE after 150 h of storage in ambient air and 89.03% after accelerated aging at 85 °C for 10 h. These findings highlight the strong potential of SWCNTs as an effective interlayer for inverted CsPbI_2.85Br_0.15 PSCs and provide a promising strategy for designing high-performance HTLs by integrating SWCNTs with self-assembled monolayers (SAMs). Full article

The Au–TiO₂ interface plays a critical role in heterogeneous catalysis and nanostructure synthesis relevant to renewable energy applications. Using Au-seeded TiO₂ nanowires as the model system, we observe that, in addition to the commonly reported orientation relationships (ORs) and atomically sharp interfaces, Au–TiO₂ interfaces can also exhibit ORs involving high-indexed planes, often accompanied by local disorder and atomic reconstructions involving multiple Ti-O monolayers. These interfacial rearrangements are promoted by high-temperature thermal treatment at 1000 °C during nanowire growth. The findings broaden our understanding of orientation relationships and interface structures in the Au–TiO₂ system, offering valuable insights into interface-driven synthesis of oxide nanostructures and guiding future strategies for interface engineering in catalytic and electronic applications. Full article

The burgeoning demand for reliable fault detection in high-voltage power equipment necessitates advanced sensing materials capable of identifying trace sulfur hexafluoride SF₆ decomposition products (SDPs). In this work, the first-principles calculations were employed to comprehensively evaluate the potential of Ir- and Pt-doped InTe (Ir-InTe and Pt-InTe) monolayers as high-performance gas sensors for the four specific SDPs (H₂S, SO₂, SOF₂, SO₂F₂). The results reveal that Ir and Pt atoms are stably incorporated into the hollow sites of the InTe monolayer, significantly reducing the intrinsic bandgap from 1.536 eV to 0.278 eV (Ir-InTe) and 0.593 eV (Pt-InTe), thereby enhancing the material’s conductivity. Furthermore, Ir-InTe exhibits selective chemisorption for H₂S, SO₂, and SOF₂, with adsorption energies exceeding −1.35 eV, while Pt-InTe shows chemisorption capability for all four SDPs. These interactions are further supported by significant charge transfer and orbital hybridization. Crucially, these interactions induce notable bandgap changes, with Ir-InTe showing up to a 65.5% increase (for SOF₂) and Pt-InTe showing an exceptional 105.2% increase (for SO₂F₂), alongside notable work function variations. Furthermore, recovery time analysis indicates that Ir-InTe is suitable for reusable H₂S sensing at 598 K (0.24 s), whereas Pt-InTe offers recyclable detection of SO₂ (5.27 s) and SOF₂ (0.16 s) at the same temperature. This work provides theoretical guidance for the development of next-generation InTe-based gas sensors for the fault diagnosis in high-voltage power equipment. Full article

During pregnancy, exposure to fine particulate matter (PM_2.5), particularly diesel exhaust particles (DEPs), elevates the risk of placental dysfunction-related pregnancy complications; however, the underlying cellular mechanisms have yet to be fully elucidated. The objective of this study was to assess the effects of PM_2.5 exposure on trophoblast functions and their interaction with endometrial stromal cells. We utilized a three-dimensional (3D) model in which human first-trimester trophoblasts (Sw71) formed blastocyst-like spheroids and were cultured with human endometrial stromal cells (HESCs). Trophoblast proliferation, migration, invasion, and 3D network formation following DEP exposure (0.5–20 μg/mL) were assessed using methyl thiazolyl diphenyl-tetrazolium bromide (MTT), wound healing, migration, and invasion assays. The expression levels of genes related to the epithelial-mesenchymal transition (EMT) were quantified by real-time reverse-transcription quantitative polymerase chain reaction (RT-qPCR). DEP exposure significantly inhibited trophoblast proliferation, migration, and invasion. DEP treatment dysregulated the EMT program by significantly decreasing the expression of key mesenchymal markers (SNAI1, SNAI2, SOX2, and KLF4) while upregulating epithelial markers. These changes may be related to inhibited trophoblast migration toward HESC monolayers and 3D invasive network formation. DEP directly impairs critical trophoblast functions that are essential for successful pregnancy. Disruption of the EMT program represents a molecular mechanism by which traffic-related air pollution contributes to placental dysfunction and pregnancy complications, highlighting the significant reproductive risks posed by ambient air pollution. Full article

Background: Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), are critical conditions lacking effective pharmacologic therapies. Lipopolysaccharide (LPS), a bacterial endotoxin, is a well-established trigger of ALI. Emerging evidence suggests that heparin derivatives may attenuate lung injury, but their mechanisms remain unclear. Methods: This study evaluated the protective effects of 2-O, 3-O desulfated heparin (ODSH) in a murine model of LPS-induced ALI. Mice received LPS intratracheally with or without ODSH pre-treatment. Lung injury was assessed by bronchoalveolar lavage fluid (BALF) analysis, Evans blue dye albumin EBDA) extravasation, and histopathology. Results: ODSH treatment significantly reduced BALF protein concentration, inflammatory cell infiltration, and EBDA leakage. ODSH preserved endothelial barrier function in vitro, as evidenced by transendothelial electrical resistance (TER) measurements in human lung microvascular endothelial cell (HLMVEC) monolayers. Histological assessment (H&E staining) and myeloperoxidase (MPO) staining demonstrated reduced lung injury and neutrophil infiltration in the ODSH group. ODSH also downregulated pro-inflammatory mediators (NF-κB, IL-6, p38 MAPK) and upregulated the anti-inflammatory cytokine IL-10. Conclusions: ODSH mitigates LPS-induced ALI by reducing vascular permeability, neutrophilic inflammation, and pro-inflammatory signaling while enhancing IL-10 expression. These findings suggest ODSH may offer a novel therapeutic approach for treating ALI. Full article

Background/Objectives: The static in vitro permeability assay based on cell monolayers has been widely used in the pharmaceutical industry and recognized by regulatory agencies as a surrogate method for BCS classification. However, the application of such an experiment to study the effects of formulations is limited by the oversensitivity to the excipient effect on drug permeability. In this article, we studied the effects of common excipients on the permeability of moderately and poorly absorbed model compounds across cell monolayers, using two approaches to control said oversensitivity. Methods: Drug permeability across MDCK-wt was assessed in the absence (control) or presence (treatment) of excipients, using minoxidil as a high-permeability marker. The effects of excipients were parameterized as a permeability ratio (PR = treatment/control) without or with normalization (nPR) by minoxidil permeability. Metrics were compared by either ANOVA (p < 0.01) or confidence intervals (CI90, as per bioequivalence metrics) to identify excipient effects. Results: Acyclovir and hydrochlorothiazide showed the highest and lowest number of interactions, respectively. The most impactful excipients were sodium lauryl sulfate, microcrystalline cellulose, and sodium starch glycolate. Unexpectedly, nPR increased the number of excipient effects across model drugs (19 vs. 21). Alternatively, the CI90 approach was more sensitive than ANOVA in identifying excipient effects (41 vs. 32). Conclusions: Minoxidil was not able to control the anticipated oversensitivity of cell-based permeability experiments. Meanwhile, ANOVA was overall able to reduce oversensitivity to excipient effects on drug permeability compared to CI90. Nonetheless, there might be a niche for CI90 analysis when comparing the performance of two formulations on the permeability of moderately and poorly absorbed drugs. Full article

A comprehensive UPLC-MS/MS method was developed and validated for the simultaneous separation and quantification of atenolol, propranolol, quinidine, and verapamil, using established intestinal permeability standards in the Caco-2 cell monolayer model. This in vitro model is widely accepted for predicting intestinal drug permeability and is formally recognized by global regulatory agencies, including the FDA, EMA, and WHO, as a surrogate for assessing drug permeability in biowaiver applications under the Biopharmaceutics Classification System (BCS) framework. Despite its regulatory importance, standardized methods for the simultaneous quantification of key permeability markers remain scarce. The selected compounds represent distinct transport pathways: paracellular (atenolol), passive transcellular (propranolol, verapamil), and P-glycoprotein-mediated efflux (quinidine). Method validation followed FDA guidelines and demonstrated high selectivity, linearity (r² > 0.998), precision, and accuracy. Solid-phase extraction enhanced recovery and reduced matrix effects. Application to Caco-2 permeability assays confirmed expected transport profiles, including P-gp inhibition effects with verapamil. By integrating multiple analytes in a single workflow, the method improves analytical throughput, supports mechanistic interpretation, and ensures consistency across assays. This advanced separation strategy, combined with sensitive mass spectrometric detection, supports regulatory and BCS-based classification studies, contributing to the standardization of permeability assessments in drug development. Full article

The internal mammary arteries (IMAs) and coronary arteries share many common characteristics. The inner layer (tunica intima, or intima) of both arteries is lined with a smooth, longitudinally orientated monolayer of endothelial cells (ECs), connective tissue, and an internal elastic lamina that separates the tunica intima from the tunica media (middle layer). The intima of IMAs is lined with an additional protective layer, the neointima, containing vascular smooth muscle cells (VSMCs). The neointima, located between the intima and internal elastic lamina, protects IMAs from damage by assisting in the remodeling of VSMCs. Coarse longitudinal folds in the internal elastic lamina of IMAs partially prevent the infiltration of VSMCs into damaged IMAs, and intimal thickening is thus less likely to occur. Inflamed IMAs resist the migration of monocytes across the endothelial layer and prevent the formation of lipid-rich macrophages (foam cells) within the subintimal or medial layers of arteries. IMAs are thus less likely to form plaques and develop atherosclerosis (AS). Higher levels of prostacyclin (PGI2) in IMAs prevent blood clotting. The anti-thrombotic agents, and production of tumor necrosis factor α (TNF-α), interferon-γ (INF-γ), and visfatin render IMAs more resistant to inflammation. An increase in the production of nitric oxide (NO) by ECs of IMAs may be due to small ubiquitin-like modifier (SUMO) proteins that alter the nuclear factor kappa B (NF-κB) and TLR pathways. The production of reactive oxygen species (ROS) in IMAs is suppressed due to the inhibition of NADPH oxidase (NOX) by a pigment epithelium-derived factor (PEDF), which is a serine protease inhibitor (SERPIN). In this review, a comparison is drawn between the anatomy of IMAs and coronary arteries, with an emphasis on how ECs of IMAs react to immunological changes, rendering them more suited for coronary artery bypass grafts (CABGs). This narrative review covers the most recent findings published in PubMed and Crossref databases. Full article