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Amendment significantly improves soil structure and promotes crop growth. To combat soil degradation and low crop yields in facility agriculture, it is crucial to study the optimal application rate of amendments. This study analyzed the effects of biochar, vermicompost, and mineral-source potassium fulvic acid on the stability of aggregate structure, soil nutrient content, and tomato yield in cambisols, providing a theoretical basis for improving the soil quality of plastic greenhouses in Southern China. A pot experiment on tomato cultivation was carried out in yellow-brown soil in plastic greenhouses. The experiment included eight treatments: 1% biochar (B1); 3% biochar (B3); 5% biochar (B5); 3% vermicompost (V3); 5% vermicompost (V5); 0.1% mineral-source potassium fulvic acid (F1); 0.2% mineral-source potassium fulvic acid (F2); and the control condition without adding soil amendments (CK). The results showed that the biochar and vermicompost treatments effectively reduced soil bulk density and increased total soil porosity. Compared to the control, treatments with soil amendments significantly increased soil pH and had different effects on soil nutrients: F2 showed the most significant improvement in the content of available nitrogen, available phosphorus, and available potassium, with an increase of 133.33%, 834.59%, and 74.34%, respectively; B3 treatment had the highest increase in dissolved organic carbon (DOC), while B5 treatment had the highest organic matter content. Compared to the CK, the particle size of the biochar treatment was mainly 0.053~0.25 mm, while the V3, F1, and F2 mainly occurred with a particle size > 0.25 mm; and V3 has the best aggregate stability. Biochar, vermicompost, and mineral potassium fulvic acid can all promote tomato yield, with the F2 and V3 treatments having a yield increase effect of over 30%. Furthermore, Pearson's correlation analysis showed a highly significant positive correlation between geometric mean diameter (GMD) and mean weight diameter (MWD), water-stable macroaggregate content (R0.25), and a positive correlation between alkaline-dissolved nitrogen, available phosphorus, dissolved organic carbon content, and aggregate stability indicators. Adding 0.2% mineral-source potassium fulvic acid optimizes cambisols' properties, enhances aggregate formation and stability, boosts tomato yield, and shows great application potential. [ABSTRACT FROM AUTHOR]

Background: Polarization of microglia, the resident retinal immune cells, plays important roles in mediating both injury and repair responses post-retinal ischemia–reperfusion (I/R) injury, which is one of the main pathological mechanisms behind ganglion cell apoptosis. Aging could perturb microglial balances, resulting in lowered post-I/R retinal repair. Young bone marrow (BM) stem cell antigen 1-positive (Sca-1+) cells have been demonstrated to have higher reparative capabilities post-I/R retinal injury when transplanted into old mice, where they were able to home and differentiate into retinal microglia. Methods: Exosomes were enriched from young Sca-1+ or Sca-1− cells, and injected into the vitreous humor of old mice post-retinal I/R. Bioinformatics analyses, including miRNA sequencing, was used to analyze exosome contents, which was confirmed by RT-qPCR. Western blot was then performed to examine expression levels of inflammatory factors and underlying signaling pathway proteins, while immunofluorescence staining was used to examine the extent of pro-inflammatory M1 microglial polarization. Fluoro-Gold labelling was then utilized to identify viable ganglion cells, while H&E staining was used to examine retinal morphology post-I/R and exosome treatment. Results: Sca-1+ exosome-injected mice yielded better visual functional preservation and lowered inflammatory factors, compared to Sca-1−, at days 1, 3, and 7 days post-I/R. miRNA sequencing found that Sca-1+ exosomes had higher miR-150-5p levels, compared to Sca-1− exosomes, which was confirmed by RT-qPCR. Mechanistic analysis found that miR-150-5p from Sca-1+ exosomes repressed the mitogen-activated protein kinase kinase kinase 3 (MEKK3)/JNK/c-Jun axis, leading to IL-6 and TNF-α downregulation, and subsequently reduced microglial polarization, all of which contributes to reduced ganglion cell apoptosis and preservation of proper retinal morphology. Conclusion: This study elucidates a potential new therapeutic approach for neuroprotection against I/R injury, via delivering miR-150-5p-enriched Sca-1+ exosomes, which targets the miR-150-5p/MEKK3/JNK/c-Jun axis, thereby serving as a cell-free remedy for treating retinal I/R injury and preserving visual functioning. [ABSTRACT FROM AUTHOR]