Guangxi Veterinary Research Institute

This work systematically investigates the influence of Mn content (0.1, 0.3, and 0.5 wt.%) on the microstructure, mechanical properties, and high-temperature stability of asymmetric extruded Mg-4.0Al-0.8Sn-0.3Ca-xMn alloys. The results demonstrate that Mn addition effectively promotes the formation of multi-scale secondary phases. Increasing the Mn content refines the average grain size from ∼2.82 µm to ∼1.89 µm and significantly modulates the recrystallization behavior of the alloy. The ATX4103-05Mn alloy (0.5 wt.% Mn) exhibits an optimal strength–ductility synergy, achieving a yield strength of 281.8 MPa and an elongation of 19.1%. Quantitative analysis reveals that this enhancement is predominantly governed by dispersion strengthening (∆σp∼34.1 MPa), with supplementary contributions from grain boundary and dislocation strengthening. Furthermore, the ATX4103-05Mn alloy shows superior resistance to abnormal grain growth after thermal exposure at 400 °C for 10 h, which is attributed to effective Zener pinning by the uniform distribution of short rod-shaped Al8Mn5 phases along the grain boundaries. This study elucidates the multi-scale strengthening and thermal stabilization mechanisms enabled by Mn microalloying, providing a viable pathway for developing high-performance, thermally stable magnesium alloys.

Fowl adenovirus serotype 4 (FAdV-4) is the primary pathogen responsible for hydropericardium-hepatitis syndrome (HHS) and is associated with high mortality rates (20–80%) in 3–6-week-old chickens. This study aimed to develop a rapid and specific method for detecting FAdV-4. Two monoclonal antibodies (mAbs 6B3 and 8G11) against the FAdV-4 penton protein were successfully generated using hybridoma technology, both of which exhibited high titers (1:100,000) and strong serotype specificity. Specificity analysis confirmed that these mAbs recognized 12 FAdV-4 isolates from diverse origins without cross-reactivity to other FAdV serotypes or common avian pathogens. On this basis, a colloidal gold immunochromatographic assay was developed; systematic optimization of its key parameters yielded an optimal labeling pH of 8.3, an antibody labeling concentration of 7.2 μg/mL, and optimal coating concentrations for the test line (T-line) and control line (C-line) of 2.5 mg/mL and 1.5 mg/mL, respectively. Performance evaluation of the method demonstrated that it achieved a detection sensitivity of 7.81 × 104 TCID₅₀/0.1 mL with a detection time of 15 min. Clinical sample validation revealed a positive concordance rate of 91.6%, a negative concordance rate of 100%, and an overall concordance rate of 98.6% relative to those of the ELISAs. The proposed colloidal gold immunochromatographic method offers advantages such as ease of operability, rapid visualization and high specificity and serves as a practical technical tool for onsite rapid diagnosis and epidemiological surveillance of FAdV-4 infection, thus it has high potential in the prevention and control of HHS.

Abstract Fowl adenovirus serotype 4 (FAdV-4) has been identified as the primary pathogen responsible for pericardial effusion-hepatitis syndrome (HHS). Since 2015, FAdV-4 has spread extensively across major poultry-producing countries, resulting in significant economic losses. Timely and accurate diagnosis of FAdV-4 infection is essential for the effective prevention and control of HHS. In this study, two nonstructural genes from FAdV-4, 100K and 22K, were cloned into the expression vector pET-32a. The recombinant 100K and 22K proteins were expressed and purified, and subsequently used as coating antigens to establish two indirect ELISAs, referred to as 100K-ELISA and 22K-ELISA, respectively. Both ELISAs demonstrated high specificity, showing no cross-reactivity with serum samples positive for other avian diseases. Furthermore, they demonstrate high sensitivity, as FAdV-4 positive serum could still be detected even when diluted to 1:1280 (100K-ELISA) and 1:640 (22K-ELISA). The assays also showed excellent repeatability, with the maximum coefficient of variation between and within batches remaining below 5%. Both ELISAs yielded positive results when applied to 50 serum samples from SPF chickens experimentally infected with FAdV-4 and negative results when applied to 50 serum samples from SPF chickens immunized with an inactivated FAdV-4 vaccine. Similarly, the field sample testing results demonstrated a significant ability to distinguish between vaccinated and unvaccinated samples. In chickens naturally infected with FAdV-4, the 100K-ELISA and 22K-ELISA showed overall concordance rates of 96.8% and 98.6%, respectively, when compared with a commercial kit coated with whole virions. These findings suggest that 100K-ELISA and 22K-ELISA, which are based on nonstructural proteins, may be effective tools for differentiating between FAdV-4 infection and vaccination, offering a promising approach for differentiating infected from vaccinated animals (DIVA) strategies in poultry.

ABSTRACT To address the urgent demand for high‐energy‐density polymer dielectrics in modern power electronics, this study developed a poly(vinylidene fluoride) (PVDF)‐based nanocomposite dielectric material. A water‐resistant and thermally stable zinc‐based metal‐organic complex (SAZn) was synthesized using 3,5‐di‐tert‐butylsalicylic acid as the ligand and zinc ions as the coordination metal, exhibiting a bandgap of 3.28 eV and dielectric constant of 7.97 (1 kHz). SAZn/PVDF composite films were fabricated via solution casting, with optimized filler‐matrix compatibility to enhance dielectric properties. Research findings: (1) SAZn induces an α → β phase transition in PVDF, elevating β‐phase content from 34.0% to 74.8% at 5 wt% loading and thereby providing high‐density intrinsic dipoles. (2) SAZn significantly reduces the crystallinity of PVDF (52.7% → 30.9% at 5 wt% loading), enhancing polarization by expanding the free volume for dipole movement. This mechanism contrasts fundamentally with conventional coordination polymer/ferroelectric polymer composites. Synergistic interaction of these dual mechanisms yields a maximum dielectric constant ( ε r ) of 19.73 at 1 kHz for the 5 wt% SAZn composite—representing a 79% enhancement over pure PVDF (11.01). Despite a moderate increase in dielectric loss (tan δ = 0.043), the composite demonstrated a discharge energy density ( U e ) of 4.39 J cm −3 and an energy efficiency ( η ) of 53.09% at 500 MV m −1 , surpassing pure PVDF ( U e = 1.74 J cm −3 , η = 47.22%). This study elucidates a novel mechanism of coordination polymers in polymer dielectric composites, providing new insights for the design of high‐energy‐density capacitors.

This study systematically examines the influence of Zn addition (≤0.6 wt.%) on the microstructure and mechanical properties of Mg-2Al-0.8Sn-0.5Ca (wt.%) alloys. Minor Zn alloying marginally increases secondary phase fraction in as-cast alloys, with complete Zn dissolution achieved after solution treatment and asymmetric severe shear extrusion. Extruded alloys exhibit non-monotonic strength evolution with Zn content, peaking at 0.2 wt.% Zn (yield strength ≈ 235.1 MPa, ultimate tensile strength ≈ 289.2 MPa), while elongation reaches 16.1%. This strength enhancement originates from synergistic grain boundary, solid-solution, and dislocation strengthening mechanisms. These results demonstrate Zn’s critical role in optimizing the strength-ductility balance of rare-earth-free magnesium alloys.

Mangiferin (MGF), a bioactive compound found in mangoes and their byproducts, possesses various pharmacological activities and holds potential for use in natural nutritional supplements and pharmaceuticals. However, the low solubility and poor bioavailability significantly limit its effectiveness. To address these limitations, this study employed the natural sweetener rebaudioside A (Reb A) to encapsulate MGF within self-assembled nanomicelle (SAM), resulting in the formation of nanoscale spherical particles with an encapsulation efficiency of 87.14% ± 0.56% and a drug loading capacity of 44.31% ± 0.28%. MGF-Reb A SAM improved both the water solubility and thermal stability of MGF through structural transformation from the crystalline to the amorphous form. Additionally, MGF-Reb A SAM exhibited sustained-release properties, with 92.32% of the MGF released within 12 h. The release kinetics followed a first-order model. In Caco-2 cell studies, MGF-Reb A SAM demonstrated good cellular compatibility and increased MGF permeability across intestinal epithelial cells by enhancing passive diffusion, thereby improving bioavailability. Pharmacokinetic analysis revealed that MGF-Reb A SAM increased the bioavailability of MGF 2.41-fold. In conclusion, the Reb A-based delivery system developed in this study enhances the physicochemical properties of MGF, offering a promising strategy for its future use in food supplements and pharmaceuticals.

Classical swine fever (CSF) is an acute and often fatal disease caused by CSF virus (CSFV) infection. In the present study, we investigated the transcriptional profiles of peripheral blood mononuclear cells (PBMCs) in pigs infected with CSFV. The results revealed that CSFV inhibits IFNα/β production, but up-regulates the expression of signal transducer and activator of transcription 1 (STAT1); this result was verified in vitro. Interestingly, STAT1 is typically a downstream target of IFNα/β, raising the question of how CSFV can inhibit IFNα/β expression, yet up-regulate STAT1 expression. To explore this further, we observed that UV-treated CSFV induced STAT1 expression. Our results demonstrated that CSFV Erns, E1, and E2 could up-regulate STAT1 expression within the host cell cytoplasm and facilitate its translocation into the nucleus. The Erns, E1, and E2 proteins also separately induced the up-regulation of interleukin (IL)-10; IL-10 acts as the communicator connecting Erns, E1, and E2 proteins to STAT1, leading to the subsequent up-regulation, phosphorylation, and nuclear translocation of STAT1. Silencing of IL-10 down-regulated STAT1 expression. Finally, MX1 and OAS1 were identified as downstream targets of the IL-10-STAT1 pathway. In summary, a novel IL-10-STAT1 pathway independent of IFNα/β induced by CSFV Erns, E1, and E2 was identified in this study.