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Titanium alloys processed by additive manufacturing (AM) are increasingly deployed in aerospace hot-section components, of which fatigue performance constitutes the life-limiting design criterion. This review establishes a temperature-dependent hierarchy of the factors governing fatigue resistance: defects dominate at room temperature, surface roughness and residual stresses exert competing influence in the intermediate regime (300–500 °C), and microstructural stability and environmental attack emerge as the controlling mechanisms above 500 °C, where oxidation-assisted cracking becomes increasingly pronounced. The synergistic interaction of cyclic plasticity, creep, oxidation, and microstructural evolution gives rise to a multi-mechanism coupling that fundamentally distinguishes high-temperature fatigue from ambient-temperature behavior. Advanced characterization techniques, physics-based and data-driven fatigue life prediction models, and post-processing strategies are critically assessed. The applicability and limitations of both traditional physics-based fatigue life prediction models and data-driven machine learning approaches are assessed, with combined protocols that integrate hot isostatic pressing, controlled heat treatment, and thermally stable surface treatments identified as essential for high-temperature service. Key gaps including the complete absence of thermomechanical fatigue data for AM titanium alloys, the long-term thermal stability of optimized microstructures, and the mismatch between the Ti-6Al-4 V-centric literature and the near-α alloys most relevant to aerospace applications, are delineated as priorities for future research.
As a widely popular berry fruit, strawberry (Fragaria × ananassa Duch.) is well-known for its attractive appearance, distinctive taste and rich nutrients. Nevertheless, strawberry undergoes rapid senescence and quality loss after harvest, which greatly reduces its edible value and marketability and results in a short storage life. Xanthan gum possesses excellent film-forming properties, while calcium chloride can maintain fruit hardness and delay physiological changes. In this study, a composite coating (XG-Gly-CaCl2) was prepared by combining 0.50% xanthan gum with 2.00% calcium chloride and characterized. XG-Gly-CaCl2 coating treatment delayed the decline in strawberry hardness and soluble solids content (SSC), inhibited color deterioration, slowed down the increase in weight loss rate and decay index, and gradually elevated phenolics, flavonoids and carotenoids throughout storage, and significantly increased anthocyanins and vitamin C (VC) contents at the late cold storage stage. Furthermore, XG-Gly-CaCl₂ coating treatment suppressed the accumulation of superoxide anion (O2·−) and hydrogen peroxide (H2O2) in strawberry, reduced malondialdehyde (MDA) content, enhanced DPPH radical scavenging activity and ferric reducing ability (FRAP), and promoted the increase in the activities of superoxide dismutase (SOD) and catalase (CAT). It also upregulated the expression level of antioxidant enzyme genes (FaMnSOD, FaCu/ZnSOD, FaFeSOD, FaCAT1, FaPOD27, FaPOD42), phenolic metabolism genes (FaPAL1, FaC4H, FaF3'H1, FaDFR, FaANS), carotenoid metabolism genes (FaPSY, FaPDS3, FaLCYB), and VC metabolism genes (FaGalDH, FaAPX, FaDHAR). Additionally, it inhibited lipoxygenase (LOX) activity and the elevated expression level of FaLOX2. This study provides a theoretical basis and reference for the application of calcium chloride-xanthan gum composite coating in postharvest strawberry preservation and lays a practical foundation for the development of novel, safe, and efficient edible coating materials for fruit preservation.
Latency-reversing agents (LRAs) are molecular entities designed to reactivate latent HIV proviruses for subsequent elimination by the immune system or antiviral therapies. Interestingly, in our systematic exploration of fungal pigment diversity, the marine-derived strain Microsphaeropsis arundinis P1B was identified as a prolific azaphilone producer through phenotype-guided screening, suggesting that such fungal compounds may serve as novel LRAs with enhanced efficacy. Further investigation of its solid-fermented rice medium yielded 18 unprecedented sclerotiorin-type azaphilones (microsphazaphilones H–Y, 1–18). Extensive spectroscopic analysis, modified Mosher’s method, TDDFT-ECD calculation, and X-ray diffraction were used to determine their structures including absolute configurations. These compounds exhibit remarkable structural novelty, manifested by features such as unprecedented di- to tetra-carbon truncations in side chains, diverse oxidative modifications (e.g., epoxidation, hydroxylation), or unique stereochemical configurations in the pyranoquinone core. Biological screening identified microsphazaphilone W (16) as a potent HIV LRA. Mechanistic studies confirmed 16 reactivated latent HIV through NF-κB pathway activation, positioning it as a promising candidate for “shock and kill” strategies.
Abstract Background The application of traditional vitamin C (VC) and sodium acetate (SA) in aquafeeds is hampered by significant limitations. VC suffers from poor stability during feed processing and storage, as well as low bioavailability. SA is highly hygroscopic, thermally unstable, and rapidly absorbed, leading to short duration of action. This study aimed to design, synthesize, and evaluate tetraacetyl vitamin C ester (TVCE), a novel VC-acetic acid conjugate, as a superior alternative. Results TVCE was successfully synthesized via a one-step acetylation reaction with high yield (90%) and purity (> 95%). By optimizing the distillation recovery process, the by-product acetic acid from the reaction was efficiently recovered and recycled. TVCE demonstrated excellent lipophilicity, remarkable thermal stability (withstanding 160 °C), and was efficiently hydrolyzed by pancreatic lipase in simulated intestinal fluid, indicating its function as a prodrug. In zebrafish, TVCE enhanced systemic antioxidant capacity (increasing superoxide dismutase activity and total antioxidant capacity, while decreasing malondialdehyde content) comparably or superiorly to sodium VC-2-phosphate, even at a lower VC-equivalent dosage. In tilapia, dietary inclusion of TVCE, particularly at 0.1%, significantly improved the weight gain rate and survival rate (P < 0.05). Notably, despite providing only 48% of the acetate equivalent found in the physical mixture (sodium VC-2-phosphate + SA) group, TVCE still demonstrated superior performance. Furthermore, TVCE supplementation ameliorated liver and intestinal health, as evidenced by reduced serum alanine aminotransferase, diamine oxidase levels, and liver total triglyceride levels, improved tissue morphology, and an optimized gut microbiota structure characterized by an increased abundance of Bacteroidota. Conclusions TVCE is successfully synthesized through a simple, green, and environmentally friendly process, which has successfully achieved the co-production of TVCE and acetic acid. TVCE effectively overcomes the stability and bioavailability issues of conventional VC and SA. In vivo studies demonstrated that TVCE significantly enhances growth performance, antioxidant status, and liver-intestine health in fish. These benefits are attributed to the synergistic effects of VC and acetic acid released upon hydrolysis, which results in a higher biological titer and achieving a "1 + 1 > 2" outcome. These findings establish TVCE as a promising multi-functional nutritional precursor with significant application potential in aquatic feeds.
A novel chalcone glycoside, named 4-hydroxy-6′′-(10′′,12′′-dimethoxy-11′′-hydroxybenzoyl)-6-O-β-D-glucopyranosyl-4′-rutinosylchalcone (1), together with six known chalcone glycosides (2–7) were obtained from Citrus medica L. var. sarcodactylis Swingle for the first time. Their structures were determined by analyzing spectral data and comparing with references. Among them, compounds 1, 3, and 5 exhibited important hepatoprotective activities at the concentration of 10 μM, with survival rates of 77.51 ± 1.05
