Search Results (163,724)

Three novel alkaloids, penicitrioids A–C (1–3), and two known compounds (4–5) were isolated from the ethyl acetate (EtOAc) extract of the solid fermentation of Penicillium citrinum VDL118, an endophytic fungus harbored in the leaves of Vaccinium dunalianum Wight (Ericaceae), a perennial evergreen shrub native to the southwestern regions of China, Myanmar, and Vietnam. Compounds 1 and 2 are novel pyridine alkaloids characterized by an unprecedented dihydrofuro[3,4-c]pyridine core, while 3 features a distinct pyrrolo[3,4-c]pyridine framework. Their structures were unambiguously established by comprehensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. In vitro antifungal assays revealed that compounds 1–5 exhibited moderate to potent inhibitory effects against five tested phytopathogenic fungi, with minimum inhibitory concentrations (MICs) ranging from 3.1 to 100 μg/mL. Notably, four of them (1–4) displayed broad-spectrum and potent activity against Gloeophyllum trabeum, Coriolus versicolor, Fusarium solani, and Botrytis cinerea, with MIC values as low as 3.1–12.5 μg/mL. Furthermore, a plausible biosynthetic pathway for compounds 1–3 was proposed. Full article

The weak-field, quasi-static regime of gravity is commonly described by the Newton–Poisson equation as an effective response law. We construct this response within a cost-first discrete variational framework. The Recognition Composition Law (RCL) uniquely selects a reciprocal closure cost within the restricted quadratic symmetric composition class; together with the discrete ledger axioms AX1–AX5 (including conservation) and standard DEC refinement, the Newton–Poisson baseline is then recovered in the instantaneous-closure limit. Conditional on Assumption AS1 (scale-free latency) and Assumption AS2 (causal frequency–wavenumber ansatz), allowing finite equilibration introduces fractional memory into the response, yielding a scale-free modification of the source–potential relation characterized by a power-law kernel $w_{\ker }\left(k\right)=1+C{(k_0/k)}^{\alpha }$ in Fourier space. The kernel exponent $\alpha =\frac{1}{2}(1-{\phi }^{-1})\approx 0.191$, where $\phi =(1+\sqrt{5})/2$, is derived from self-similarity of the discrete ledger closure; the amplitude $C={\phi }^{-2}\approx 0.382$ is identified as a hypothesis from a three-channel factorization argument. We evaluate this quasi-static kernel-motivated response against SPARC galaxy rotation curves under a strict global-only protocol (fixed $M/L=1$, no per-galaxy tuning, conservative ${\sigma }_{\mathrm{tot}}$), using a controlled multiplicative surrogate for the full nonlocal disk operator implied by the kernel. In this deliberately over-constrained setting, the surrogate interface achieves $\mathrm{median}({\chi }^2/N)=3.06$ over 147 galaxies (2933 points), outperforming a strict global-only NFW benchmark and remaining less efficient than MOND under identical constraints. The analysis is restricted to the non-relativistic, quasi-static sector and should be read as a falsifier-oriented galactic-regime consistency check of the scaling window, not as a relativistic completion or a claim of Solar System viability without additional UV regularization/screening. Full article

Fishways play a critical role in restoring river connectivity and conserving fishery resources, yet their efficiency is often limited by mismatches between hydraulic conditions and species-specific behavioral traits. To quantify the upstream migration behavior of fish under the combined influence of flow heterogeneity and schooling effects, this study examined the endangered species L. elongata in the Yangtze River Basin. Volitional swimming behavior was tested in an open-channel flume under three spatially heterogeneous flow regimes (I: Low–Moderate–High; II: High–Moderate–Low; III: Moderate–High–Low). A video monitoring system recorded the upstream movement of solitary fish and three-individual schools. Swimming trajectories, upstream migration time, preferred flow velocities, and schooling metrics—including nearest neighbor distance (NND) and mean pairwise distance (MPD)—were analyzed. Linear mixed-effects models were employed to account for repeated measures and individual variability. Results showed that schooling behavior significantly enhanced upstream migration efficiency: schooling fish arrived at the target area on average 8.93 s earlier than solitary individuals (p < 0.01), while flow condition alone had no detectable effect on arrival time. L. elongata consistently preferred low-velocity zones (0.20–0.50 m/s) and avoided high-velocity regions (0.75–1.25 m/s), with meandering upstream trajectories predominating. NND showed no significant differences across flow conditions (p > 0.05), indicating stable schooling cohesion. However, MPD increased significantly under Flow III compared to Flows I and II (p < 0.01), suggesting that higher flow heterogeneity leads to more dispersed group spacing while overall cohesion is maintained. Distinct movement strategies were observed: solitary fish predominantly utilized boundary regions as hydraulic refuges (wall-following: 63.8–80.5%), whereas schools exhibited greater spatial exploration and reduced wall-following. These findings demonstrate that schooling enhances migration efficiency while preserving a cohesive group structure and that flow heterogeneity influences within-group spatial organization. To optimize fishway performance for L. elongata, we recommend maintaining flow velocities within 0.20–0.50 m/s. This study provides scientific guidance for hydraulic regulation in fishway design and habitat restoration, emphasizing the combined effects of flow heterogeneity and schooling behavior on migration performance. Full article

The objective of this study is to develop and assess the feasibility of utilizing lotus (Nelumbo nucifera Gaertn.) leaf extract as a green corrosion inhibitor for copper in a sulfuric acid environment. The inhibitory efficacy was comprehensively evaluated using a multi-technique approach, incorporating electrochemical measurements, weight loss analysis, theoretical analysis, and surface morphological characterization. The experimental results demonstrate that the lotus leaf extract functions as an efficient corrosion inhibitor for copper, achieving an inhibition efficiency of 88.07% at 700 mg/L by effectively suppressing both cathodic and anodic corrosion processes. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed the protective effect, whereas X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) identified functional groups and surface interaction between metal and inhibitor. Theoretical calculations further confirmed the involvement of nitrogen (N) and oxygen (O) as the key active sites. Adsorption behavior adheres to the Langmuir isotherm model, involving both physical and chemical adsorption processes that inhibit the Cu⁺→Cu²⁺ oxidation reaction. This study demonstrates acid-resistant protection of copper using lotus leaf extract. Full article

Cancer therapies are increasingly reliant on immunotherapeutic interventions; however, the persistent emergence of primary, adaptive, and acquired resistance severely limits durable clinical efficacy. Circular RNAs (circRNAs), distinguished by their extreme structural stability and covalently closed loops, have recently been established as potent orchestrators of this immune evasion. This review systematically synthesizes current advancements detailing how circRNAs undermine anti-tumor immunity across diverse malignancies. Specifically, we delineate their critical roles in post-transcriptionally upregulating immune checkpoint molecules (e.g., PD-L1), mediating intercellular immunosuppression via exosomal transfer, and metabolically reprogramming the tumor microenvironment to drive CD8+ T-cell exhaustion and macrophage polarization. Ultimately, we conclude that translating these molecular insights into clinical practice is paramount. Beyond serving as predictive biomarkers, engineering circRNA-targeted therapies and exploiting tumor-specific circRNAs to develop novel anti-tumor vaccines represent essential, paradigm-shifting strategies to definitively overcome immune checkpoint inhibitor resistance. Full article

The application of biostimulants is a promising tool for enhancing plant growth and crop quality in the context of sustainable and resilient agricultural production. This study evaluated four microbial biostimulants (IMB1–4) on Sonchus oleraceus L. under field and pot cultivation. Our results indicate that the growing system was a more dominant factor than biostimulants in influencing plant performance. For morphological and growth traits, biostimulants generally had a neutral or negative impact compared with untreated plants, with IMB3 consistently showing the lowest performance. Field-grown plants, especially the untreated ones, excelled in plant weight and leaf count, while pot-grown plants treated with IMB2 and IMB4 achieved higher leaf weight per plant, leaf area, and chlorophyll index (SPAD). Specifically, untreated field plants recorded the highest biomass, whereas IMB2 and IMB4 optimized leaf traits in pots. Biostimulant applications enhanced fat content and energetic value, with IMB1 and IMB2 yielding the highest protein levels. Pot cultivation favored the accumulation of nitrogen, phosphorus, and sodium, while IMB2-treated pot plants proved most effective for maximizing overall nutrient content. The phytochemical profile also varied by system: pot-grown plants yielded higher total phenols, particularly with IMB3, while field-grown plants recorded higher flavonoids, especially with IMB4. Furthermore, untreated or IMB3-treated pot plants exhibited the highest antioxidant activity, significantly outperforming field-grown counterparts. In conclusion, while biostimulants did not improve morphological and growth traits, they significantly enhanced the nutritional and phytochemical quality of S. oleraceus L., particularly in the pot cultivation system, where specific biostimulants (IMB2 and IMB3) resulted in nutrient-dense crops with high antioxidant value. Full article

Capsicum annuum is a Solanaceae crop that is sensitive to cold, which affects its growth and development upon prolonged exposure and ultimately reduces yield. In response, a complex regulatory network of cold-responsive genes is activated. Earlier studies have shown that SnRKs play a positive role in enhancing cold tolerance in different crops, including peppers; however, the underlying molecular mechanisms and downstream targets have yet to be fully elucidated. In this study, yeast hybrid screening using CaSnRK2.4 identified a potential interacting partner CaPDX1. The interaction between CaPDX1 and CaSnRK2.4 was further confirmed through Y2H, luciferase complementation, and bimolecular fluorescence complementation assays. Subcellular localization showed that CaPDX1 and CaSnRK2.4 are localized in the nucleus as well as in the cell membrane. Silencing of CaPDX1 through VIGS showed increased susceptibility of peppers to cold stress, negatively influenced antioxidant enzymatic activities, and increased relative electrolyte leakage and malondialdehyde levels. Conversely, transient overexpression of CaPDX1 in peppers enhanced cold tolerance by reducing the accumulation of REL and MDA. Ectopic expression of CaPDX1 in Arabidopsis thaliana significantly improved its cold tolerance, accompanied by enhanced activity of antioxidant enzymes and increased chlorophyll content. In summary, these results indicate that CaPDX1 is a positive regulator of cold tolerance in pepper, and its mechanism of action involves interaction with CaSnRK2.4 and the regulation of physiological and molecular responses in pepper under cold stress. Full article

Background/Objectives: High-risk prostate cancer patients undergoing radical prostatectomy remain at significant risk of biochemical recurrence and metastasis. Immediate adjuvant external beam radiotherapy (EBRT) has been proposed to improve outcomes, but its role compared to observation remains debated due to potential toxicity and uncertain overall survival benefit. To evaluate the efficacy and safety of immediate adjuvant EBRT versus observation following radical prostatectomy in men with high-risk prostate cancer. Methods: A meta-analysis was conducted according to PRISMA guidelines. We sought to include both randomized controlled trials (RCTs) and observational studies published between 2005 and 2025; however, no observational studies meeting the predefined criteria were identified. Therefore, only RCTs comparing immediate adjuvant EBRT with observation in patients with adverse pathological features and undetectable postoperative PSA were included. Primary outcomes were biochemical recurrence-free survival (BCR-FS), metastasis-free survival (MFS), and overall survival (OS). Secondary outcomes included toxicity and quality of life (QoL). Data were pooled using Mantel–Haenszel and inverse variance methods, and heterogeneity was assessed with I² statistics. Results: Four RCTs (n = 1987) met the inclusion criteria. Adjuvant EBRT significantly improved progression-free survival (PFS) (HR = 0.38; 95% CI: 0.20–0.74; p = 0.004) and metastasis-free survival (HR = 0.70; 95% CI: 0.54–0.92; p = 0.01). However, OS benefit was not statistically significant (HR = 0.88; 95% CI: 0.59–1.32; p = 0.55). Heterogeneity was substantial for some outcomes (I² up to 71%). Adjuvant EBRT was associated with higher genitourinary and gastrointestinal toxicity compared to observation. Conclusions: Immediate adjuvant EBRT after radical prostatectomy improves PFS and MFS in high-risk prostate cancer but does not confer a clear OS advantage. Treatment decisions should be individualized, balancing disease-control benefits against toxicity risks. Observation with early salvage RT remains a reasonable alternative in selected patients. Full article

Chitosan nanoparticles (Ch NPs) are versatile nanomaterials with expanding agricultural and biomedical applications, highlighting the need for reproducible, low-cost, and scalable synthesis methods to ensure their safe and widespread use in biological systems. This study presents a simple ionic-gelation protocol using a serological pipette–needle dropwise system that minimizes reagent waste and requires no sophisticated equipment. The synthesized Ch NPs were characterized by UV–Vis spectroscopy, ESEM, TEM, EDS, DLS, XRD, and FTIR, confirming nanoscale size, strong positive surface charge, and characteristic chitosan–TPP interactions. To establish a standardized biological safety assessment framework, three representative bioassays were implemented across microbial, plant, and mammalian systems. Antibacterial testing against Xanthomonas oryzae pv. oryzae (Xoo) using a resazurin-based microdilution assay revealed a minimum inhibitory concentration (MIC) of 128 µg/mL, whereas bulk chitosan showed no inhibition up to 512 µg/mL. Phytotoxicity and seed germination assays on rice (Oryza ‘KDML105’) demonstrated no inhibitory effects on germination, with over 90% germination by day 3 and significantly enhanced seedling growth parameters (p < 0.05) at 64–128 µg/mL, indicating non-phytotoxicity. MTT assays confirmed that Ch NPs were non-toxic to both human skin cell lines (HDF and HaCaT) across 2.5–160 µg/mL, showing enhanced cell viability in HDF cells at specific concentrations and stable viability in HaCaT cells, indicating overall biocompatibility. Importantly, all bioassays were conducted under aligned concentration ranges to enable cross-system comparison and reproducibility. This integrated workflow links nanoparticle synthesis with a standardized, multi-system evaluation strategy, supporting the safe application of Ch NPs in biological systems. Full article

Titanium and its alloys are used in dental and orthopedic implants. However, long-term stability remains a clinical challenge. To overcome this limitation, surface modification has been investigated to improve surface properties. Our previous study demonstrated that the immobilization of secretory leukocyte protease inhibitor (SLPI) on the titanium surface promotes osteoblast adhesion, proliferation, and differentiation in vitro. The current study demonstrated the first in vivo evaluation of SLPI as a bioactive coating for medical implants. Grade 5 titanium screws were coated with 10 µg/mL of recombinant human SLPI (rhSLPI) for 24 h via simple physical adsorption, and the results were preliminarily validated via FE-SEM and ELISA. These SLPI-coated titanium screws (TiSs) were then placed in the tibia of Sprague–Dawley rats for 4 and 8 weeks. The hematological and biochemical parameters (BUN, Creatinine, AST, and Troponin I) demonstrated no acute systemic alterations within the 8-week period across all groups. Moreover, micro-computed tomography (micro-CT) and histological analysis revealed significantly higher bone volume fraction (%BV/TV) at 4 weeks compared to uncoated controls (20.64% 2.452% vs. 11.73% 0.524%). Finally, the biomechanical stability of implants, assessed using the removal torque test, showed that TiSs showed higher strength compared to Ti at both 4 and 8 weeks. In conclusion, this study represents a novel approach to transitioning rhSLPI-coated titanium evaluation from in vitro models to an in vivo rat model. rhSLPI surface functionalization enhances early-stage osseointegration and improves implant mechanical stability without acute hematological and biochemical alterations. These proof-of-concept findings suggest the potential of SLPI as a bioactive coating strategy. Full article

Background/Objectives: Uroflowmetry is done in the surveillance period after End-to-end Anastomotic Urethroplasty for pelvic fracture urethral injury. But is maximum flow rate a reliable surrogate for urethral calibre in these cases? The above question laid the foundation of the study. The aim of the study was: “Is uroflowmetry alone sufficient to predict a successful outcome following urethroplasty after pelvic fracture urethral injury (PFUI)?” Methods: We conducted a prospective masked study of all patients undergoing end-to-end anastomosis (EEA) urethroplasty for PFUI from January 2017 to September 2022. The first follow-up was 4 weeks after surgery, micturating cystourethrogram (MCU) was done after urethral catheter removal and at the same time, uroflowmetry was also done. The second follow-up was 6 months after surgery, when uroflowmetry was repeated, and urethroscopy was performed. The urologist performing urethroscopy was blinded to the uroflowmetry results. Results: In total, 26 patients were included in the study. After 6 months, 1 patient had poor flow (maximum flow rate [Q max] < 10 mL/s), 7 patients had flow with Q max 10–15 mL/s, and 18 patients had normal flow (Q max > 15 mL/s). On urethroscopy, all patients had a normal and easily passable urethra. The International Prostate Symptom Score (IPSS) and quality of life (QoL) scores showed a positive correlation. The urologist performing urethroscopy and the investigator recording uroflowmetry reached different conclusions. Conclusions: A reduced peak on uroflowmetry after EEA urethroplasty in PFUI does not always indicate surgical failure. Urethroscopy enables direct visualisation of the anastomotic site and provides more detailed information than uroflowmetry. The IPSS score and quality of life are more important than Q max alone. Full article

Sulfate-reducing ammonium oxidation (SRAO) is an emerging anaerobic autotrophic nitrogen removal process that combines ammonium oxidation with sulfate reduction. However, it faces some challenges, such as the slow growth of autotrophic microorganisms, weak synergistic interaction between different microorganisms, and poor substrate transfer capability. Herein, graphene oxide (GO) was added to a lab-scale bioreactor to promote SRAO reaction, and its effect on nitrogen removal was systematically investigated. The results demonstrated that GO served not only microbial carriers but also electron shuttles, which were conducive to microbial spatial distribution and better electron transfer, improving the sulfur cycle-driven multi-pathway nitrogen removal performance. The addition of 50 mg/L GO not only enhanced the SRAO activity and increased the ammonium removal efficiency by 24.7%, but also reduced the effluent nitrite concentration and promoted nitrogen production. After reaction, the main functional groups on the surface of GO had been changed, and the composite aggregates of microorganisms were formed. Mass balance analysis revealed that SRAO was the dominant pathway, while Anammox and sulfur-autotrophic denitrification (SADN) played complementary roles. Moreover, after adding GO, the relative abundances of Desulfosarcinaceae and Bacillus, which were functional microorganisms in the SRAO reaction, were increased by 35.7% and 58.5%, respectively. This study will provide an in-depth understanding of the mechanisms for nitrogen removal in the SRAO bioreactor. Full article

This study investigated sub-basin variability in dissolved (dBa)–excess particulate (Ba_xs) barium relationships and Ba flux patterns across the western and central Mediterranean Sea during late spring 2017 (PEACETIME cruise). The dBa concentrations increased from ~35 nmol L⁻¹ near the surface to ~70 nmol L⁻¹ at 2500 m, consistent with the relatively weak vertical dBa gradient typical of the Mediterranean. Depth profiles of dBa showed distributions consistent with Ba_xs dynamics associated with organic matter remineralization at mesopelagic depths (100–1000 m). Ba_xs exhibited basin-dependent maxima, with lower (<300 pM) depth-weighted average concentrations confined to the upper mesopelagic in the Tyrrhenian and Ionian basins and higher (up to 650 pM) and deeper concentrations (to ~1000 m) in the Algero–Provençal basin, suggesting contrasted remineralization horizon structures. A simplified steady-state 1-D approach yielded first-order mesopelagic dBa removal fluxes of ~0.3 ± 0.1 µmol m⁻² d⁻¹ in the Algero–Provençal basin to 1.7 ± 1.0 µmol m⁻² d⁻¹ in the Ionian basin, consistent with previous estimates obtained from a coupled dBa and parametric optimum multiparameter approach. Together, these paired dissolved and particulate Ba observations refined the Mediterranean Ba cycle framework and provided additional geochemical constraints for interpreting mesopelagic carbon remineralization processes. Full article

Microplastics (MPs), particularly low-density polyethylene (LDPE), are widespread pollutants in aquatic environments and may affect cyanobacterial physiology. This study investigated the concentration-dependent effects of LDPE-MPs on the physiology and transcriptomic responses of Arthrospira platensis. Cultures were exposed to 10–5000 mg/L LDPE-MPs (nominal size ≤ 500 µm) for 16 days. Low to moderate concentrations (10–1000 mg/L) produced minimal effects on growth, biomass accumulation, or pigment contents. In contrast, higher concentrations (3000–5000 mg/L) were associated with reduced growth and biomass, accompanied by declines in chlorophyll a (Chl a) and phycobiliproteins over time. By day 16 at 5000 mg/L, biomass and Chl a decreased to 1.47 ± 0.03 g/L and 8.39 ± 0.24 µg/mL, respectively, compared with 1.64 ± 0.04 g/L and 10.81 ± 0.52 µg/mL in the control (p < 0.05). Accordingly, Chl a yield decreased by 13%. Field-emission scanning electron microscopy revealed adhesion of LDPE particles to filament surfaces and the formation of extracellular polymeric substance (EPS)-rich aggregates, which may influence light availability and nutrient exchange. Transcriptomic analysis indicated changes in several metabolic pathways, including nitrogen assimilation, photosynthetic electron transport, carbon metabolism, and metal homeostasis, together with differential expression of genes related to stress responses and EPS biosynthesis. Overall, these findings suggest that relatively high concentrations of LDPE microplastics may influence physiological and metabolic processes in A. platensis. Full article