Search Results (44,980)

Sortase A (SrtA) enzymes covalently anchor surface proteins to Gram-positive bacterial cell walls, promoting colonization and virulence. In Streptococcus pneumoniae, previous studies identified both a domain-swapped dimer and an active refolded monomer, but the active enzyme has not been characterized at the structural and residue-specific level. Here, we performed quantitative proteomic comparisons of wild-type and SrtA knockout strains that confirmed the loss of multiple LPxTG-containing virulence factors, including ZmpB, NanA, and IgA1 protease, consistent with an essential role for SrtA in surface protein anchoring. To enable mechanistic studies, we established a biochemical framework to produce monomeric Streptococcus pneumoniae SrtA by refolding and developed a gel-based assay using recombinant substrates to monitor catalytic activity. The refolded monomer, but not the swapped dimer, catalyzed cleavage and transpeptidation of a canonical LPxTG substrate in a metal-independent manner under the conditions examined. We further report high-resolution NMR backbone assignments for the active monomer and identify substrate-induced chemical shift perturbations that localize to the active site. Together, these findings provide an integrated proteomic, biochemical, and NMR characterization of monomeric, catalytically active Streptococcus pneumoniae SrtA and reveal residue-specific interactions with a canonical LPNTG recognition peptide. Full article

Carbon nanoparticles (CNPs) have attracted considerable attention for biomedical applications owing to their excellent biocompatibility, tunable optical properties, and low toxicity. In this study, we report a simple, rapid, and cost-effective one-pot bottom-up synthesis of fluorescent carbon nanoparticles using propanoic acid as a novel liquid carbon precursor. Unlike conventional approaches that often require high temperatures, lengthy reaction times, or complex procedures, the proposed method enables efficient nanoparticle synthesis under mild thermal conditions. The use of propanoic acid enabled carbonization under relatively mild conditions, yielding nanoparticles with excellent aqueous dispersibility. Following the synthesis of CNPs using propanoic acid as the carbon precursor, the nanoparticles were treated with ethylenediamine (EDA) as a nitrogen source and surface-passivating agent, yielding nitrogen-doped carbon nanoparticles (NCNPs). The resulting NCNPs exhibited approximately fourfold higher fluorescence intensity than the undoped CNPs. The NCNPs exhibited strong visible photoluminescence with a dominant emission band in the green spectral region (490–540 nm), which is advantageous for cellular imaging due to reduced background interference and improved imaging selectivity. Furthermore, the NCNPs demonstrated high aqueous solubility, cellular permeability, and excellent photostability under the in vitro imaging conditions investigated. The bioimaging capability of the NCNPs was evaluated using human lung fibroblasts and lung cancer cells. Confocal fluorescence microscopy revealed efficient cellular uptake and successful nuclear labeling without observable photobleaching and morphological alterations. These findings demonstrate the feasibility of using propanoic acid-derived NCNPs as fluorescent probes for cellular imaging and suggest their potential for future applications in bioimaging, biosensing, and related biomedical research. Further studies are warranted to evaluate their long-term biological safety and performance. Full article

The increasing use of electric vehicles has led to a growing demand for rare-earth elements, particularly neodymium (Nd), which is a critical component of Nd–Fe–B permanent magnets used in traction motors. End-of-life electric vehicle motors are therefore considered promising secondary resources for Nd recovery. In this study, a pyrometallurgical process using non-ferrous smelting slag as a flux was proposed for recovering Nd from Nd–Fe–B magnets contained in waste electric vehicle motors. Steel and magnet fractions obtained from a dismantled motor were melted at approximately 1600 °C under an air atmosphere, and Fe₂O₃ was added as an oxidizing agent to promote the selective oxidation of Nd. The oxidized Nd was subsequently partitioned into the slag phase as Nd₂O₃ through metal–slag separation. The effects of the slag flux addition ratio, Fe₂O₃ content, slag flux type, and crucible material on Nd recovery behavior were systematically investigated. Increasing the fayalite-based slag flux addition enhanced Nd transfer into the slag phase, and the highest Nd recovery of approximately 80% was obtained at a slag flux addition ratio of 30 wt%. The addition of 2 wt% Fe₂O₃ was found to be suitable for promoting stable Nd oxidation and efficient slag–metal separation. The non-ferrous smelting slag exhibited chemical and phase characteristics comparable to those of synthetic fayalite slag flux, resulting in similar Nd recovery performance. In addition, the crucible material significantly affected the process stability and Nd recovery behavior. Although a carbon crucible showed relatively high Nd recovery, severe slag foaming and crucible erosion occurred during melting. In contrast, alumina and MgO crucibles provided stable process conditions with comparable Nd recovery behavior, whereas zirconia crucibles caused relatively higher Nd loss. These results demonstrate that non-ferrous smelting slag can be effectively used as a flux for the pyrometallurgical recovery of Nd from end-of-life electric vehicle motors, offering a potential route for sustainable rare-earth recycling. Full article

Municipal dog shelters are often grouped as outsourced facilities despite operator differences. We analyzed 33,875 dog admissions and 90 municipality-year observations from 2016 to 2025 across nine Korean municipalities, with three per operator category; operator type was fixed and nested within municipality. Among 32,838 known outcomes, live-release rates were 69.1%, 58.1%, and 40.0%, and euthanasia rates were 14.0%, 22.8%, and 42.5% in corporation-operated, veterinary hospital-operated, and individually operated shelters, respectively. The corporation live-release estimate ranged from 62.6% to 72.0% under alternative classifications of unresolved records. Small-sample cluster-robust comparisons were imprecise: the individually versus corporation-operated euthanasia odds ratio was 4.72 (95% confidence interval, 0.40–56.35), and every operator interval included 1.0. Contextual adjustment yielded odds ratios of 0.97 for both outcomes for veterinary hospital- versus corporation-operated shelters. Among 33,836 admissions with common 180-day follow-up, live-release rates were 59.9%, 53.0%, and 39.8%, and euthanasia rates were 9.1%, 16.7%, and 42.0%; annual odds ratios were 1.05 (0.93–1.19) and 0.90 (0.78–1.05), respectively. Results describe operator-linked municipal systems, not causal effects. Standardized follow-up, complete reporting, capacity monitoring, and larger prospective studies are needed. Full article

UAVs increasingly rely on accurate SLAM for aerial mapping and inspection in GPS-denied environments. 3D Gaussian Splatting (3DGS) has opened a new direction for UAV mapping by allowing SLAM systems to build dense, photorealistic, and renderable maps. Yet in 3DGS SLAM the map is optimized from the pose graph, so a false loop closure can deform both the UAV trajectory and the Gaussian map consumed by downstream UAV autonomy. Reliable loop admission is therefore relevant to safe GPS-denied operation because it protects the state and map estimates on which autonomous functions depend. The present work evaluated this upstream estimation-integrity problem; it did not measure closed-loop guidance, control, or navigation-safety outcomes. We address the loop-admission problem that arises after a place-recognition (PR) module proposes a candidate loop and relative-pose seed. GSSeq is a rendered-reference sequential verifier that uses the current Gaussian map as active evidence before inserting a loop factor. It renders RGB-D references with the PR seed, checks LiDAR/rendered-depth consistency and image/rendered-reference consistency over active support, and propagates the seed through a short query trajectory window. A loop is admitted only when this evidence remains geometrically supported and photometrically stable. On fixed LiDAR-PR candidate sets spanning MARS-LVIG, MUN-FRL, and independent NTU-VIRAL aerial sequences together with ground-mobility benchmarks, GSSeq provides a competitive precision-oriented operating point while suppressing false loop admissions. Thresholds calibrated only on NTU-VIRAL spms_01 combine rendered RGB agreement with LiDAR-submap geometry and are then frozen for spms_02. On this held-out sequence, GSSeq rejects all seven false-positive BTC factors while retaining one of three true-positive factors. The trajectory-to-map experiment reduced ATE RMSE from $2.609\mathrm{m}$ to $1.417\mathrm{m}$ and improved selected-view PSNR from $13.80\mathrm{dB}$ to $16.46\mathrm{dB}$. These results show that rendered verification can preserve an aligned, renderable UAV trajectory-map pair before unsupported loop factors reshape the SLAM map. Full article

This study examines how social media platform environments influence adolescent consumer replication behavior specifically within sports content, athletic apparel, and active lifestyles through psychological engagement mechanisms, including parasocial interaction, self-congruence, and perceived source credibility. Drawing on media ecology theory and platform affordance perspectives, the study compares users of YouTube, TikTok, and Instagram. To better capture the complex structural mechanics across platforms, the investigation is guided by empirical research questions rather than simple linear hypotheses. Data were collected from 402 high school students in South Korea who had experience with influencer-based social media content. Respondents were categorized based on their primary platform of engagement. The dataset was analyzed using independent-samples t-tests and Welch’s ANOVA with Games–Howell post-hoc tests to examine differences across gender and platform groups. The results indicate significant gender differences in psychological engagement and behavioral outcomes, with female adolescents showing higher levels of parasocial interaction, self-congruence, and consumer replication behavior than male adolescents. Platform-based comparisons further reveal significant differences across user groups. TikTok users reported higher levels of parasocial interaction, self-congruence, source credibility, and consumer replication behavior compared to Instagram users, while differences between TikTok and YouTube users were observed primarily in consumer replication behavior. Although TikTok users demonstrated the highest mean values across several constructs, the relatively small sample size of this group should be considered when interpreting the robustness of platform-level differences. Overall, the findings suggest that platform affordances shape adolescent psychological engagement and subsequent consumer imitation behaviors beyond mere exposure intensity. This study contributes to social media and behavioral science literature by highlighting how platform-specific environments structure psychological engagement and influence consumer replication processes among adolescent users. Full article

Efficient removal of organic dye pollutants remains challenging owing to the limited adsorption capacity and poor reusability of most conventional adsorbents. Herein, rhombic-dodecahedral zeolitic imidazolate framework-67 (ZIF-67) was successfully fabricated via a facile aqueous strategy. The obtained ZIF-67 exhibited a high BET specific surface area of 1842.31 m² g⁻¹, with a maximum Langmuir adsorption capacity of 156.74 mg g⁻¹ toward methyl orange (MO). The adsorption kinetics successfully followed the pseudo-second-order model, and the material maintained 88.9% dye removal efficiency after six ethanol-regeneration cycles. Common inorganic anions (HCO₃⁻ and SO₄²⁻) presented a distinct inhibitory effect on MO adsorption. Static electrostatic potential calculations and hydrated molecular dynamics simulations were further adopted to reveal the interfacial adsorption behavior on typical ZIF-67 (100) and (110) facets. Based on equilibrated trajectories of 40–50 ps, both facet systems exhibited stable temperature and potential-energy fluctuations. The dominant Co–O(MO) radial distribution distances for (100) and (110) facets were determined to be 5.825 Å and 5.775 Å, respectively, both far beyond conventional short-range Co–O coordination lengths. The stronger radial ordering of the (110) facet suggests facet-sensitive interfacial organization, rather than direct Co–O chemical bonding during MO adsorption. Full article

Background/Objectives: Glucagon-like peptide-1 (GLP-1) receptor agonists and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonists are used long term for obesity and diabetes, but their oesophageal safety is uncertain: weight loss may reduce Barrett’s oesophagus and adenocarcinoma risk, whereas delayed gastric emptying may worsen reflux. We performed a genetic assessment of target-mediated oesophageal safety. Methods: Two-sample drug-target Mendelian randomisation used cis-expression quantitative trait loci for both receptors (31,684 participants). Outcomes were European genome-wide association studies of gastro-oesophageal reflux disease and the Barrett’s oesophagus/oesophageal adenocarcinoma axis, with a trans-ancestry squamous cell carcinoma comparator. A prespecified gated workflow required positive-control validation, and target specificity required genetic colocalisation (posterior probability of a shared causal variant ≥ 0.70). Candidate metabolic mediators were examined in two-step analyses, and findings were replicated in an independent Finnish population (FinnGen R12). Results: Genetically proxied GLP-1 receptor expression was not associated with reflux disease (odds ratio 0.97, 95% confidence interval 0.85–1.11), arguing against a substantial target-mediated reflux liability; the GIP receptor estimate was not estimable. For the Barrett’s oesophagus/adenocarcinoma endpoint, estimates were near the null for both receptors (GLP-1R 0.96, 0.47–1.96; GIPR 1.00, 0.42–2.37); colocalisation was uninformative because the outcome loci carried no detectable association signal, and wide intervals did not exclude moderate effects. The null reflux findings were reproduced in FinnGen. Adiposity showed the most consistent pathway association, whereas glycaemic traits did not, including when HbA1c was instrumented from a population-based genome-wide association study providing an order of magnitude more variants. Conclusions: GLP-1 receptor perturbation was not associated with reflux disease, providing cautious genetic reassurance. For the Barrett’s oesophagus/adenocarcinoma axis, no target-specific association was demonstrated, but colocalisation was uninformative because the outcome loci carried no detectable signal, and imprecision precludes firm safety conclusions; larger adenocarcinoma-specific studies are warranted. Full article

The relatively new subject, symplectic geometry, has been studied the past five decades. Symplectic geometry is the mathematical subject studying the geometry of symplectic manifolds. A symplectic manifold is an even-dimensional smooth manifold equipped with a closed non-degenerate two form. This paper surveys the progress on the study of symplectic geometry during the past five decades. It deals with a brief history of symplectic geometry and symplectic topology, Arnold’s conjecture, pseudoholomorphic curves, the convexity properties of a moment map, recent results on Hamiltonian and non-Hamiltonian symplectic group actions, the classification of symplectic group actions, recent results on the symplectic embedding problems, the theory of Gromov–Witten invariants, Lagrangian Floer homology, the Fukaya category, and mirror symmetry. Full article

This study examines whether and when environmental, social, and governance (ESG) performance alleviates financial constraints, focusing on firm life cycle heterogeneity. Using a panel of Korean listed firms from 2011 to 2021, we employ industry-and-year fixed-effects regression to identify the empirical relationship of ESG on financial constraints proxied by the KZ index or Z-score. We classify firm life cycle stages using both retained-earnings- and cash-flow-based measures to capture distinct dimensions of firm development. We document that ESG performance significantly relaxes financial constraints, with governance being the most influential sub-dimension in our sample. Importantly, this effect is highly state-dependent: ESG is largely ineffective in the introduction stage but becomes economically and statistically significant from the growth stage onward, with the strongest impact observed in early-growth and declining firms. Our findings challenge the notion of uniformly priced ESG benefits and demonstrate that ESG operates as a contingent financial mechanism whose effectiveness critically depends on firm life cycle stages. Full article

Objectives: To assess the clinical viability of compressed sensing magnetization, we prepared a rapid acquisition gradient echo (CS-MPRAGE) for brain volume measurement by comparing its scan time and image quality with standard MPRAGE. Methods: In this retrospective study, we analyzed a total of 40 morphologically normal MRIs from relatively young subjects (mean age 27.03 ± 5.02, range 19~40, F:M = 33:7) who underwent both CS-MPRAGE and standard MPRAGE. MRI was performed with a 3T MR scanner using a 64-channel head coil. Volumetric data analysis was conducted using commercial AI-powered quantification software. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR _{gray matter/white matter}) were measured and compared. Qualitative analysis based on overall image quality, deep gray matter delineation, artifacts, and gray–white matter differentiation was rated on a five-point visual scoring system. Statistical analyses included paired t-tests, intraclass correlation coefficients (ICCs) and Pearson correlation. Results: CS-MPRAGE had a significantly shorter scan time than standard MPRAGE (1:46 vs. 5:20 min; p < 0.001). Whole-brain volume was similar (standard-MPRAGE, 1176.89 ± 105.36; CS-MPRAGE, 1181.14 ± 105.62 mL; r = 0.988; ICC, 0.9754–0.9931). Gray matter and regional lobe volumes were comparable, while the white matter volume was slightly larger with CS-MPRAGE. CNR of the gray–white matter was significantly higher with CS-MPRAGE (left, 30.45 ± 11.21 vs. 49.53 ± 32.71; right, 30.73 ± 11.97 vs. 46.89 ± 30.40; p = 0.0001) while SNR were similar across key brain regions. Conclusions: CS-MPRAGE provides high-quality 3D images and reliable volume data with significantly reduced acquisition time and comparable image quality. Full article

This paper proposes a unified invariant-set-based reliable control framework for Takagi–Sugeno (T–S) fuzzy systems subject to actuator saturation and faults. The considered model incorporates both matched actuator faults and mismatched external disturbances, which provides a more realistic control setting. To address these challenges, a unified control framework is developed to systematically account for input constraints and actuator fault effects. A sequence of nested invariant ellipsoidal sets, together with corresponding set-dependent control gains, are constructed to guarantee that state trajectories starting within the designed outer invariant sets progressively converge toward a minimized target set. Based on this structure, relaxed LMI-based conditions are derived to compute both the invariant sets and the associated control laws via convex optimization. Finally, numerical examples demonstrate the effectiveness of the proposed method. Full article

Alternaria alternata can produce alternariol (AOH), alternariol monomethyl ether (AME), altenusin (ALN), and altenuene (ALT) on fruits and vegetables. Much is unknown about the biosynthetic gene clusters (BGCs) of secondary metabolites (SMs) including ALT in A. alternata isolated from strawberries. In the current study, we sequenced the whole genome of AOH- and AME-producing A. alternata KACC 411286 isolated from strawberry jam and carried out comparative analyses of the ALT BGC in its genome with those of other fungal strains after verification of its production of ALN and ALT. Our data showed that the assembled genome of A. alternata KACC 411286 is 34.2 Mb in size with 10 chromosomes. Gene Ontology analysis showed that genes involved in RNA transcription and protein synthesis and turnover are enriched in the genome of A. alternata KACC 411286. We identified a total of 40 SM BGCs, including the ALT BGC, in A. alternata KACC 411286. The comparative analysis showed that ALT BGCs are highly conserved between two A. alternata (KACC 411286 and ATCC 66981) and A. arborescens EGS 39–128. The functional conservation analyses of all six ALT biosynthetic genes also revealed that each gene in A. alternata KACC 411286 shares high amino acid and DNA sequence identity (above 78% identity) with its corresponding gene in four other Alternaria spp. except pksI in A. arborescens EGS 39–128 (55% identity at both the protein and DNA levels) and pksI in A. tenuissima BMP 0304 (53% at the DNA level). Our findings could provide a molecular basis for understanding the biosynthetic mechanisms of SMs, including ALT, in A. alternata KACC 411286 to reduce the contamination of fruits with multiple mycotoxins. Full article

Background/Objectives: Ephedrae Herba (EH) is widely used in traditional East Asian medicine, but safety concerns regarding its adverse events remain. This study aimed to investigate EH-associated adverse events using clinical pharmacovigilance data and to perform exploratory in silico analyses to propose potential molecular mechanisms underlying these adverse events. Methods: A disproportionality analysis was performed using individual case safety reports from the Korea Adverse Event Reporting System database. EH-containing products were compared with other herbal medicine products using reporting odds ratios (RORs), proportional reporting ratios, and information components. Network pharmacology identified adverse event-related genes and pathways, and protein–protein interaction networks were constructed. Molecular docking predicted direct adverse event-associated targets of ephedrine and compared mechanisms with control compounds (aconitine and spinosin). Results: Four adverse-event signals were detected in the primary analysis: sleep disorder, dry mouth, insomnia, and palpitations. Sensitivity analysis identified four signals, with three (dry mouth, insomnia, and palpitations) consistent across both analyses; constipation emerged only in the sensitivity analysis. Conclusions: Adverse event-associated network analysis predicted key pathways: Neuroactive ligand–receptor interaction, Pathways of neurodegeneration, and Dopaminergic synapse. Molecular docking predicted that ephedrine may act on downstream signaling mechanisms shared by neurotransmitter systems, including the dopaminergic system, distinct from control compounds. Full article

Urban particulate matter (UPM) is a major environmental pollutant known to induce systemic inflammation. While its respiratory toxicity is well-documented, the potential vulnerability of the female reproductive system to inhaled UPM remains a critical concern. In this study, we evaluated female reproductive outcomes in a murine model following repeated short-term intratracheal instillation of UPM (40–200 mg/kg) for a month. Our results demonstrate that while UPM exposure induced robust, dose-dependent pulmonary inflammation, characterized by immune cell infiltration (CD45+, F4/80+, and Ly6G+) and upregulation of pro-inflammatory (Il-6, Il-1β, and Tnfα) and fibrotic (Col1a1 and Tgfβ1) markers, no apparent adverse effects were observed in the reproductive endpoints examined. No significant alterations were observed in maternal pregnancy outcomes, including oocyte recovery rates, fertilization competence, gestation duration, litter size, and postnatal development of pups. Furthermore, the mRNA expression of inflammatory markers in the ovaries and uteri was not detectable. Direct in vitro exposure of two-cell embryos to UPM did not interfere with preimplantation embryo development. Although benzanthracene slightly reduced the blastocyst formation rate, UPM and polycyclic aromatic hydrocarbons, major toxic components of UPM, did not severely compromise preimplantation embryo development in vitro. In conclusion, these findings suggest that marked UPM-induced pulmonary inflammation is not accompanied by substantial alterations in the female reproductive outcomes examined under short-term exposure conditions. Full article