BAY-94-9392

Early-stage chlorosis due to iron deficiency is a critical limitation in direct-seeded rice (DSR) cultivation under aerobic and alkaline soil conditions, where iron bioavailability is severely restricted. This study presents a nano-engineered FeS-palygorskite composite (Fs-Pg) as a sustainable alternative to conventional ferrous sulfate (FeSO₄), enabling prolonged ferrous ion availability under alkaline conditions. Response Surface Methodology (RSM) optimized a controlled release of 2.13 mg/kg iron over 29.6 days for Fs-Pg, maintaining higher ferrous ion content (0.43 mg/kg), in contrast to FeSO₄, which showed a rapid release (3.44 mg/kg) with lower ferrous ion retention (0.19 mg/kg) within 8.6 days at their respective optimized dosages. Korsmeyer-Peppas model (n = 0.738) was the most fitted kinetic model endorsed a non-Fickian, dual-controlled release mechanism for Fe²⁺ release, driven by diffusion and sulfide-mediated slow dissolution. Significant enhancement in seedling physiological parameters (after 30 days) included improved germination rate (8.80 %), root length (20.66 %), biomass accumulation (fresh weight: 68.37 %; dry weight: 35.29 %) and overall vigor index (47.26 %) as compared to FeSO₄. The treatment also enhanced iron uptake in shoots (9.58 %) and roots (10.36 %) relative to FeSO₄. Fs-Pg application markedly elevated antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase, polyphenol oxidase and peroxidase) and boosted biochemical attributes (phenolics, flavonoids, protein and chlorophyll content), contributing to reduced oxidative stress and enhanced redox homeostasis. Free radical scavenging assays further confirmed its superior antioxidative potential. Overall, this study offered a sustainable nanonutrient solution for augmented bioavailable iron under aerobic conditions in DSR, coupled with enhanced antioxidant defense, and improved physiological growth to effectively mitigate early-stage chlorosis under alkaline stress.

We aimed to explore whether the imaging of antiporter system x_C ^- of immune cells with (4S)-4-(3-¹⁸F-fluoropropyl)-l-glutamate (¹⁸F-FSPG) PET can assess inflammatory bowel disease (IBD) activity in murine models and patients (NCT03546868). Methods: ¹⁸F-FSPG PET imaging was performed to assess IBD activity in mice with dextran sulfate sodium-induced and adoptive T-cell transfer-induced IBD and a cohort of 20 patients at a tertiary care center in South Korea. Immunohistochemical analysis of system x_C ^- and cell surface markers was also studied. Results: Mice with experimental IBD showed increased intestinal ¹⁸F-FSPG uptake and xCT expression in cells positive (+) for CD11c, F4/80, and CD3 in the lamina propria, increases positively associated with clinical and pathologic disease activity. ¹⁸F-FSPG PET studies in patients, most of whom were clinically in remission or had mildly active IBD, showed that PET imaging was sufficiently accurate in diagnosing endoscopically active IBD and remission in patients and bowel segments. ¹⁸F-FSPG PET correctly identified all 9 patients with superficial or deep ulcers. Quantitative intestinal ¹⁸F-FSPG uptake was strongly associated with endoscopic indices of IBD activity. The number of CD68⁺xCT⁺ and CD3⁺xCT⁺ cells in 22 bowel segments from patients with ulcerative colitis and the number of CD68⁺xCT⁺ cells in 7 bowel segments from patients with Crohn disease showed a significant positive association with endoscopic indices of IBD activity. Conclusion: The assessment of system x_C ^- in immune cells may provide diagnostic information on the immune responses responsible for chronic active inflammation in IBD. ¹⁸F-FSPG PET imaging of system x_C ^- activity may noninvasively assess the IBD activity.