Search Results (2,278)

Intermediate-mass black holes (IMBHs; $M_{\mathrm{BH}}\approx {10}^{3–5} {\mathrm{M}}_{\odot }$) play a critical role in understanding the formation of supermassive black holes in the early universe. In this study, we expand on Nguyen et al.’s simulated measurements of IMBH masses using stellar kinematics, which will be observed with the High Angular Resolution Monolithic Optical and Near-infrared Integral (HARMONI) field spectrograph on the Extremely Large Telescope (ELT) up to a distance of 20 Mpc. Our sample focuses on both the Virgo Cluster in the northern sky and the Fornax Cluster in the southern sky. We begin by identifying dwarf galaxies hosting nuclear star clusters, which are thought to be nurseries for IMBHs in the local universe. As a case study, we conduct simulations for FCC 119, the second faintest dwarf galaxy in the Fornax Cluster at 20 Mpc, which is also fainter than most of the Virgo Cluster members. We use the galaxy’s surface brightness profile from Hubble Space Telescope (HST) imaging, combined with an assumed synthetic spectrum, to create mock observations with the HSIM simulator and Jeans Anisotropic Models (JAMs). These mock HARMONI data cubes are analyzed as if they were real observations, employing JAMs within a Bayesian framework to infer IMBH masses and their associated uncertainties. We find that ELT/HARMONI can detect the stellar kinematic signature of an IMBH and accurately measure its mass for $M_{\mathrm{BH}}\gtrsim {10}^5{\mathrm{M}}_{\odot }$ out to distances of ∼20 Mpc. Full article

Human cleft lip morphopathogenesis is a complicated process involving multiple genes and proteins. Certain factors like muscle segment homeobox 1 (MSX1) and 2 (MSX2) as well as receptor-like tyrosine kinase (RYK) are important during lip embryogenesis, while others like nuclear factor kappa-B protein 65 (NFκB p65), C-C motif chemokine ligand 4 (CCL4), and pentraxin 3 (PTX3) regulate local inflammation and immunomodulation. The exact role of these factors in human cleft morphopathogenesis remains uncertain and limits the opportunity to improve cleft treatment and possible prophylaxis. Immunohistochemistry (IHC) for MSX1, RYK, NFκB p65, and CCL4 proteins and chromogenic in situ hybridization (CISH) for MSX2, RYK, and PTX3 genes were used to analyze postnatal human cleft lip tissue (15 patients) and control tissue (6 patients). The semiquantitative counting method was used to assess factor/gene-signal-containing cells. Statistical analysis was performed. IHC findings showed decreased MSX1, NFκB p65, and CCL4 proteins in cleft lip connective tissue and endothelium, while RYK protein was decreased only in cleft connective tissue. CISH showed increases in MSX2 and RYK gene-signal-containing cells in cleft lip tissue while PTX3 did not differ from controls. Multiple statistically significant correlations were calculated. The findings are discussed in detail to determine their significance in cleft lip morphopathogenesis. Full article

Calcium/calmodulin-dependent protein kinase II (CaMKII) comprises multiple isoforms with distinct nuclear variants that exert transcriptional control in a context-dependent manner. Among them, CaMKIIδB and δ9 in the heart, and CaMKIIγ in the nervous system, have emerged as regulators of chromatin dynamics, transcription factor activity, and developmental gene programs. Nuclear localization is driven by splice-dependent nuclear localization sequences, with phosphorylation at defined serine residues modulating import and retention. Evidence supports CaMKII-dependent phosphorylation of class IIa HDACs (Ser467/Ser632 in HDAC4), linking CaMKII to MEF2 activation in cardiac hypertrophy, and interactions with NF-κB and HSF1 further expand its nuclear repertoire. In the nervous system, CaMKIIγ contributes to kinase-dependent gene expression, potentially influencing plasticity and disease susceptibility. While these mechanisms highlight nuclear CaMKII as an isoform-specific regulator of transcription, direct evidence remains elusive, and several CaMKII putative substrates require further validation. This review synthesizes current knowledge on nuclear CaMKII isoforms, emphasizes established mechanistic pathways, and outlines unsolved questions critical for understanding their roles in development, disease progression, and therapeutic targeting. Full article

CYP24A1, a mitochondrial cytochrome P450 enzyme, plays a critical role in the catabolism of active vitamin D metabolites and is a key regulator of local vitamin D signaling in the small intestine. While traditionally studied in the context of renal physiology, increasing evidence highlights its distinct regulatory mechanisms and functional significance within the intestinal epithelium. This review explores the molecular architecture, tissue-specific expression patterns, and multifactorial regulation of CYP24A1 in enterocytes, encompassing nuclear receptor signaling, epigenetic and post-transcriptional control, and environmental influences such as inflammation, diet, and the gut microbiota. We discuss how intestinal CYP24A1 modulates the expression of vitamin D target genes involved in transcellular calcium absorption and epithelial barrier function, and how its dysregulation contributes to gastrointestinal disorders including inflammatory bowel diseases, celiac disease, microbiota dysbiosis, and colorectal cancer. In addition, we examine preclinical and translational evidence supporting CYP24A1 as a potential therapeutic target. Emerging strategies such as selective enzyme inhibitors, microbiota modulation, RNA-based technologies, and personalized supplementation approaches are considered in the context of restoring local vitamin D bioactivity and mineral homeostasis. Together, this review underscores the clinical importance of intestinal CYP24A1 and highlights novel opportunities for targeted interventions in vitamin D-responsive gastrointestinal pathologies. Full article

Magnetic nanoparticles (MNPs) perturb magnetic field homogeneity, influencing transverse relaxation and the full width at half maximum (FWHM) of nuclear magnetic resonance (NMR) spectra. In Nuclear Magnetic Resonance (NMR), this appears as decay of the free induction decay (FID) signal, whose relaxation rate determines spectral FWHM. In D₂O containing MNPs, both nanoparticles and solvent molecules undergo Brownian motion and diffusion. Under a vertical main field ($B_0$), MNPs respond to their magnetization behavior, evolving toward a dynamic steady state in which the time-averaged distribution of local field fluctuations remains stable. The resulting spatial magnetic field can thus characterize field homogeneity. Within this framework, Monte Carlo simulations of spatial field distributions approximate the dynamic environment experienced by nuclear spins. NMR experiments confirm that increasing MNP concentration and particle size significantly broadens FWHM, while stronger $B_0$ enhances sensitivity to MNP-induced inhomogeneities. Full article

Background: Spermatogenesis depends on precise cytoskeletal regulation, particularly the microtubule system; however, the mechanisms governing tubulin homeostasis during meiosis are poorly defined. While the E3 ubiquitin ligase Hyd (Hyperplastic discs), the Drosophila homolog of UBR5 (Ubiquitin Protein Ligase E3 Component N-Recognin 5), plays roles in diverse cellular processes, its precise role in male meiosis is unknown. This study aims to define the function and expression dynamics of Hyd during Drosophila spermatogenesis and elucidate whether it acts independently of its canonical ligase activity. Methods: Using Drosophila genetics, immunofluorescence, CRISPR/Cas9-mediated tagging, and mosaic clonal analysis, we characterized Hyd expression and function in the testis. Hyd knockdown and rescue experiments were performed with wild-type and catalytically inactive transgenes. β2-tubulin expression and microtubule organization were assessed in hyd mutant clones. Results: Hyd exhibits a dynamic, stage-specific expression pattern, localizing to nuclear and meiotic structures. Hyd loss led to meiotic arrest, disrupted spindle formation, aberrant centrosome behavior, and failure of spermatid elongation. Genetic rescue demonstrated that both wild-type and catalytically inactive Hyd partially restored spermatid elongation, indicating a catalysis-independent role. Furthermore, Hyd deficiency resulted in β2-tubulin overexpression, disrupted microtubule organization, and abnormal spermatocyte morphology. Conclusions: Hyd ensures meiotic fidelity in Drosophila by fine-tuning β2-tubulin expression independently of its E3 ubiquitin ligase activity. These findings reveal a non-proteolytic function for UBR5/Hyd in cytoskeletal regulation during male gametogenesis, providing new insights into tubulin homeostasis in meiosis. Full article

The development of nuclear energy in Jordan necessitates a detailed understanding of local meteorological behavior, particularly during unfavorable weather conditions. This study uses the METEO mesoscale model to simulate wind fields, vertical motions, and surface–air temperature differences under unfavorable wind directions (15°, 105°, and 195°) and two wind speeds (1 m/s and 5 m/s), across cold season (January) and warm season (July), near the Samra Energy Power Plant (SEPP)—a proposed location for Jordan’s nuclear plant. Simulations reveal that low wind speeds create stable atmospheric layers with limited vertical motion (±0.1 m/s), enhancing the risk of pollutant accumulation in valleys. Higher wind speeds promote vertical mixing (up to ±0.15 m/s) and lower temperature gradients (within ±0.2 °C), dispersing pollutants more efficiently. These results suggest that specific wind thresholds could determine the spatial extent of emergency response zones, including “shelter-in-place” areas and evacuation perimeters. This study offers valuable insights for nuclear safety planning and environmental risk assessment in complex terrain. Full article

The canine parturition cascade involves decreased placental progesterone (P4) signaling mediated through its nuclear receptor PGR in decidual cells, leading to increased trophoblast production of PGF2α that promotes luteolysis, placentolysis, and myometrial contractility. A local role for glucocorticoids in initiating parturition through increased placental availability of cortisol and glucocorticoid receptor (GR/NR3C1), possibly affecting P4-PGR signaling, has been suggested. Primary uterine inertia (PUI) is a major cause of canine dystocia, but its pathophysiology remains unclear. Here, we hypothesized that dysregulated placental signaling could contribute to PUI. The availability of parturition cascade-related factors was assessed in placentae of dogs with PUI and during physiological prepartum luteolysis (LUT). Compared with LUT, PUI had no significant changes in prostaglandin-related factors PTGS2, PTGES, and HPGD (p > 0.05), but had lower PGF2α synthase PGFS/AKR1C3 (p < 0.001), and higher PGT abundance (p < 0.001). PUI had increased PGR transcript and protein levels (p < 0.001), but the same number of decidual cells (p > 0.05). GR/NR3C1 availability was reduced in PUI (p < 0.05), along with decreased placental cortisol-to-cortisone conversion. Our findings suggest that PUI could be associated with disturbances of the parturition cascade, possibly due to inadequate P4-PGR and glucocorticoid signaling in the placenta. Full article

The Blackspot Seabream, Pagellus bogaraveo, is a commercially valuable species widely distributed in the northeastern Atlantic and Mediterranean. Its biology makes it vulnerable to overfishing, but its population structure and ontogenetic migration strategy remain unclear. Building on previous work based on microsatellite markers, we expanded the investigation by analysing the mitochondrial Control Region (CR) to complement nuclear data. We analysed 199 specimens from 13 sites and combined the new CR sequences with 129 published records to achieve the broadest coverage in terms of biogeographic and genetic data. We calculated genetic diversity and performed AMOVA, pairwise ΦST comparisons, and multivariate analyses. Eighty-eight haplotypes were identified, showing high haplotype diversity (Hd = 0.767–0.945) and moderate nucleotide diversity (π = 0.0026–0.0054). Most genetic variation occurred within populations, and overall analyses indicated genetic homogeneity. However, pairwise analysis and AMOVA confirmed significant differentiation of the Azores population. These results confirm extensive genetic connectivity throughout the Atlantic–Mediterranean range of P. bogaraveo, likely due to a combination of large larval dispersal and a common spawning migration strategy, but identify the Azores as a genetically distinct unit. This highlights the need to consider both large-scale connectivity and local divergence in fisheries management. Full article

The tokay gecko (Gekko gecko) is a widely distributed lizard species in Southeast Asia, with significant importance in traditional medicine and the pet trade. Previous studies using mitochondrial DNA sequences revealed extensive genetic variation across its range, indicating the presence of distinct evolutionary lineages. In this study, we assessed the nuclear genetic variation and phylogenetic pattern of G. gecko using the recombination activating gene 1 (RAG1). We analyzed 105 RAG1 sequences from 16 localities across Thailand, Laos, and Cambodia, along with additional sequences from GenBank. Sequence analysis revealed 20 variable sites and 20 haplotypes (TgR1–TgR20). Haplotype network and phylogenetic analyses revealed strong regional structuring and at least three distinct evolutionary lineages (A–C), supported by the species delimitation test (PTP). Both red- and black-spotted morphs were present in different clades, indicating that external coloration does not correspond to genetic differentiation at this locus. Our results support the presence of distinct evolutionary lineages in G. gecko and emphasize the importance of integrative taxonomy for accurate species delimitation. These findings have implications for conservation, sustainable management, and regulation of international trade in this commercially exploited species. Full article

In this work, the associative behavior of Gum Arabic in aqueous solutions was investigated through dynamic light scattering, nuclear magnetic resonance, and transmission and scanning electron microscopy. It was shown that in small associates, the spherical polysaccharide units have predominant sizes of 2–8 and 9–20 nm. The average hydrodynamic diameter of diffusing structural units, calculated on the basis of NMR experiment, turned out to be close to 20 nm, which corresponds with electron microscopy data. Based on geometric considerations and the composition and supramolecular structure of Gum Arabic, we calculated the parameters of branched chains of Gum Arabic. A possible “crown” model of polysaccharide chain association into spherical blocks is presented. The developed model allowed us to describe the effects observed during the time-extended association of Gum Arabic particles (molecules) in aqueous solutions, leading first to blocks’ swelling, then the appearance of local gelation, and only then to the creation of dense protective layers on the surfaces. It was established that the tendency of amphiphilic Gum Arabic molecules to form complexes both among themselves and with various surfaces and the possibility of forming viscous gel-like layers on the interfaces underly its use in many natural, food, technical, and technological applications, including emulsification. Full article

Background: As a key contributor to metabolic disorders, obesity is recognized as a critical global health challenge. Adipocyte differentiation depends on the mitotic clonal expansion (MCE) phase, which is controlled by oxidative balance and transcription factors like C/EBPβ. Sesaminol, a lignan derived from Sesamum indicum, has potent antioxidant properties. This study aimed to investigate whether sesaminol suppresses adipogenesis by modulating ROS signaling, MCE, and the Nrf2-ARE pathway. Methods: In the early period of adipogenic induction, 3T3-L1 preadipocytes received treatment with sesaminol. Adipogenic development was evaluated through Oil Red O staining together with the assay of GPDH activity. Assays of cell proliferation and expression of cell cycle-related proteins, along with ROS measurement, qRT-PCR, Western blotting, and immunofluorescence, were performed to evaluate the effects on oxidative stress, transcriptional regulation, and AMPK-Nrf2 signaling. Results: Sesaminol significantly inhibited lipid accumulation and GPDH activity without cytotoxicity. It suppressed MCE by inhibiting DNA synthesis and reducing the expression of cyclin E1/E2 and CDK2. Sesaminol decreased C/EBPβ expression and its nuclear localization, resulting in lower levels of C/EBPα and PPARγ. It also reduced intracellular ROS, promoted nuclear translocation of Nrf2, and upregulated antioxidant genes HO-1 and GCLC. AMPK phosphorylation was concurrently enhanced. Conclusions: Sesaminol inhibits early adipogenesis by suppressing ROS-mediated MCE and activating the AMPK-Nrf2-ARE signaling pathway, leading to downregulation of key adipogenic transcription factors. The present study supports the potential of sesaminol as an effective strategy for obesity prevention. Full article

This study reports the construction and validation of a CAFLUX (Chemically Activated Fluorescent Expression) HepG2 reporter cell line engineered to express a histone H2B–green fluorescent protein (H2B–GFP) fusion protein under the control of a dioxin-responsive cytochrome P450 1A1 (CYP1A1) promoter. A lentiviral construct containing a synthetic promoter with multiple dioxin-responsive elements (DREs) upstream of the H2B–EGFP coding sequence was cloned into the pFUGW vector, packaged in human embryonic kidney (HEK) 293FT cells, and used to transduce HepG2 hepatocellular carcinoma cells. Stable clones obtained by limiting dilution were screened for GFP expression in response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The resulting CAFLUX HepG2 cells exhibited dose-dependent nuclear GFP fluorescence when exposed to aryl hydrocarbon receptor (AhR) agonists, with limits of detection of approximately 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon (PAH). This reporter activity correlated with endogenous CYP1A1 mRNA expression as determined by quantitative polymerase chain reaction (qPCR), confirming that GFP signals reflected native transcriptional responses. In functional assays, curcumin suppressed GFP expression in a concentration-dependent manner and induced apoptotic morphology at higher doses, while extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSCs) significantly reduced both GFP fluorescence and CYP1A1 mRNA levels, suggesting an inhibitory effect on AhR-driven transcription. The CAFLUX HepG2 reporter system therefore provides a sensitive and reproducible platform for real-time, nuclear-localized monitoring of AhR-mediated gene expression. Its responsiveness to both agonists and antagonists underscores its potential utility in toxicological evaluation, drug discovery, and the investigation of EV-mediated signaling in liver cancer models. Full article

In this paper, an underwater salvage robot is developed to retrieve foreign objects scattered in nuclear reactor pools. The robot mainly consists of an ROV platform and a 3-DOF Delta robotic arm. Utilizing fused IMU and LED beacon visual data for localization, it achieves pool traversal via six dynamically controlled thrusters. An improved YOLOv8s algorithm is employed to identify foreign objects in underwater environments. During traversal, the robot identifies and retrieves foreign objects along the way. The prototype of the robot was subjected to a series of experiments in an indoor pool. Results show that the improved YOLOv8 algorithm achieves 92.2% mAP, surpassing the original YOLOv8s and Faster-RCNN by 3.7 and 3.3 percentage points, respectively. The robot achieved a foreign-object identification rate of 95.42% and a retrieval success rate of 90.64% under dynamic traversal conditions, indicating that it meets the operational requirements and has significant engineering application value. Full article

Helical coiled tube (HCT) heat exchangers (HXs) are used in the nuclear industry, particularly in the residual heat removal systems of nuclear power plants (NPPs) and steam generators for small modular reactors. In this study, a single-phase CFD model was developed to investigate non-uniform circumferential distributions in the local wall heat transfer characteristics of a vertical HCT to obtain localized information critical for the safety of NPPs. In a comparison, the predicted circumferential heat transfer characteristics agreed well with the measured data. Governed by centrifugal/gravitational forces, these non-uniform distributions are clearly visible in the results, explaining the test data. We performed additional simulations of the conjugated heat transfer from the hot fluid of the shell side to the cold fluid of the tube side, confirming that the inhomogeneity of circumferential distributions in HCTs is due to the assumption of a constant heat flux boundary condition. Full article