Accurate and generalizable pathological segmentation is essential for clinical deployment. However, existing methods remain challenged by cross-center domain shifts and ambiguous tissue boundaries, often relying on spurious domain-specific correlations and producing unreliable predictions in structurally complex regions. To address these issues, we propose the Causal-Evidential Generalization Network (CaEG-Net) for pathological image segmentation, which draws on ideas from causal inference and Dempster-Shafer evidence theory. Specifically, we incorporate a Causal Constraint Mechanism to mitigate spurious correlations through sample reweighting, thereby promoting the learning of domain-invariant morphological features. Furthermore, we design an Evidential Boundary Constraint module to model pixel-level uncertainty and suppress unreliable boundary responses in ambiguous regions, enabling more accurate boundary delineation. Extensive experiments on six datasets, including four public benchmarks and two in-house clinical datasets, demonstrate that CaEG-Net achieves superior segmentation performance in comparison to existing methods. The code was released at https://github.com/Bonjour-492/CaEG-Net.
Plant extracts are commonly incorporated into the processing of agricultural products to exert preservative effects. However, the molecular mechanisms underlying their decay-inhibiting effects remain poorly understood. Identifying plant extracts with potent anti-spoilage activity is especially crucial for mung bean sprouts (Vigna radiata), which are highly susceptible to rapid decay after harvest. In this study, we comparatively evaluated the efficacy of five extracts (mango seed MS, loquat leaf LL, rosemary R, horsetail H, mate tea MT) on preserving sprouts quality. LL extract achieved optimal quality retention, whereas R accelerated spoilage; MS, H, and MT produced intermediate effects. Integrated transcriptomic and metabolomic analyses revealed that LL extract maintained quality by: (i) reinforcing membrane integrity through the activation of antioxidant system and the suppression of lipid degradation; (ii) enhancing biosynthesis of phenylpropanoids and alkaloids, particularly methyl 4-hydroxycinnamate, naringenin and securinine, which inhibited enzymatic browning and microbial proliferation; and (iii) promoting fructose accumulation while downregulating genes associated with cell wall degradation, thereby delaying tissue softening and water loss. In contrast, R extract depleted these protective metabolites, exacerbated oxidative damage and browning. Notably, securinine, an endogenous metabolite sustained by LL, suppressed the growth of spoilage microorganisms and delayed sprout deterioration. Our work provides insights into plant extract–mediated postharvest quality maintenance and highlights securinine as a promising candidate for developing effective strategies to suppress decay in highly perishable vegetables.
During the withering process of white tea, the degradation of astringent flavonol glycosides (FGs) plays a vital role in enhancing quality. However, the molecular mechanism underlying this process remains unclear. This study aimed to clarify the molecular mechanism and physiological significance of the degradation of nine key astringent FGs during white tea withering. Two key genes, CsGH3B (β-glucosidase) and CsPPO1 (polyphenol oxidase), were identified using FGs quantification, transcriptomics, and weighted gene co-expression network analysis (WGCNA). Prokaryotic expression, protein purification, and in vitro enzyme activity assays confirmed that recombinant CsGH3B hydrolyzed all nine FGs, whereas recombinant CsPPO1 did not. Transient inhibition of CsGH3B expression in tea leaves significantly increased the contents of the nine FGs (P < 0.05). Overexpression of CsGH3B in Nicotiana benthamiana promoted the hydrolysis of FGs, further confirming its in vivo function. Molecular docking revealed that CsGH3B binds to FGs through hydrogen bonds and hydrophobic interactions. Our results indicate that dehydration stress during white tea withering induces the accumulation of reactive oxygen species, which may be associated with the upregulation of CsGH3B, catalyzing the hydrolysis of FGs to generate potent antioxidant flavonol aglycones (quercetin and kaempferol) that potentially contribute to oxidative stress alleviation. This process also reduces the bitterness and astringency of white tea products by lowering FG content, thereby improving taste quality. Together, these findings provide a molecular-level insight into the concept that "adversity yields fine tea" and offer a potential theoretical basis for postharvest flavor regulation and quality improvement of white tea.
One new lignan, ocigralignan A (1), and one new phenylpropanoid, 3-amino-1-(4-hydroxy-3-methoxyphenyl)propane-1, 2-diol (2), together with six known compounds (3–8) were isolated from the essential oil of Ocimum gratissimum L. The structures and absolute configurations of 1 and 2 were elucidated by spectroscopic methods, including 1D and 2D NMR spectroscopy as well as ECD analysis. Most of the isolated compounds exhibited significant antifungal activities against Alternaria arborescens and Aspergillus flavus, with minimum inhibitory concentrations (MICs) ranging from 1 to 8 μg/mL. Notably, compound 8 displayed potent antifungal activity comparable to the positive control nystatin, with an MIC value of 1 μg/mL. Additionally, compounds 1 and 5 demonstrated considerable antioxidant activity, achieving DPPH radical scavenging rates of 85.17% and 96.51%, respectively, at a concentration of 1 mg/mL.
Ammonium perchlorate (AP) is the most widely used oxidizer in solid propellants, and its thermal decomposition directly governs the combustion performance. Consequently, extensive research has focused on developing catalytic additives to promote AP thermal decomposition. Currently, AP combustion catalysts are predominantly transition metal-based compounds such as ferrocene derivatives and iron-based catalysts, although these can improve combustion efficiency to some extent, they inevitably introduce metal impurities that compromise combustion performance. This work explores ethylenediammonium-based salts with oxidizing anions as AP thermal decomposition catalysts, synthesized three salts [enH2](ClO4)2·1/2H2O (1), [enH2](NO3)2 (2) and [enH2](BF4)F (3). Catalytic tests demonstrated that all three salts significantly promote AP decomposition, with 1 exhibiting the optimal performance: lowered the decomposition temperature by 164.7 ℃, reduces the apparent activation energy (Ea) by 106.4 kJ·mol−1, and enhances the apparent total heat release (Q) by 94%. TG-FTIR-MS analysis reveals the thermal decomposition mechanism of AP, compound 1 effectively increases the concentration of reactive oxygen species, thereby facilitating the rapid oxidation of NH3. Theoretical calculations indicate that 1 exhibits highly efficient electron transfer and excitation. This work advances the development of metal-free catalytic systems and provides a new design reference for high-efficiency solid propellant catalysts.
