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Freshwater microorganisms are an essential component of the global biogeochemical cycle and a significant contributory factor in water quality. Unraveling the mechanisms controlling microbial community spatial distribution is crucial for the assessment of water quality and health of aquatic ecosystems. This research provided a comprehensive analysis of microbial communities in Florida freshwater springs. The 16S rRNA gene sequencing and bioinformatics analyses revealed the bacterial compositional heterogeneity as well as numerous unique ASVs and biomarkers in different springs. Statistical analysis showed both geographic distance and environmental variables contributed to regional bacterial community variation, while nitrate was the dominant environmental stressor that shaped the bacterial communities. The phylogenetic bin-based null model characterized both deterministic and stochastic factors contributing to community assembly in Florida springs, with the majority of bins dominated by ecological drift. Mapping of predicted pathways to the MetaCyc database revealed the inconsistency between microbial taxonomic and functional profiles, implying the functional redundancy pattern. Collectively, our work sheds insights into the microbial spatial distribution, community assembly, and function traits in one of the world's most productive aquifers. Therefore, this work provides a unique view of the health of Florida's artesian springs and offers new perspectives for freshwater quality assessment and sustainable management. • Different springs exhibited distinct microbial community characteristics. • Bacterial communities were predominantly assembled by stochastic processes. • Nitrate was the dominating environmental stressor shaping bacterial communities. • Spring water bacterial communities showed functional redundancy pattern. [ABSTRACT FROM AUTHOR]

Influenza is caused by a respiratory virus and has a major global impact on human health. Influenza A viruses in particular are highly pathogenic to humans and have caused multiple pandemics. An important consequence of infection is viral pneumonia, and with serious complications of excessive inflammation and tissue damage. Therefore, simultaneously reducing direct damage caused by virus infection and relieving indirect damage caused by excessive inflammation would be an effective treatment strategy. Lycium barbarum glycopeptide (LbGp) is a mixture of five highly branched polysaccharide-protein conjuncts (LbGp1-5) isolated from Lycium barbarum fruit. LbGp has pro-immune activity that is 1–2 orders of magnitude stronger than that of other plant polysaccharides. However, there are few reports on the immunomodulatory and antiviral activities of LbGp. In this study, we evaluated the antiviral and immunomodulatory effects of LbGp in vivo and in vitro and investigated its therapeutic effect on H1N1-induced viral pneumonia and mechanisms of action. In vitro , cytokine secretion, NF-κB p65 nuclear translocation, and CD86 mRNA expression in LPS-stimulated RAW264.7 cells were constrained by LbGp treatment. In A549 cells, LbGp can inhibit H1N1 infection by blocking virus attachment and entry action. In vivo experiments confirmed that administration of LbGp can effectively increase the survival rate, body weight and decrease the lung index of mice infected with H1N1. Compared to the model group, pulmonary histopathologic symptoms in lung sections of mice treated with LbGp were obviously alleviated. Further investigation revealed that the mechanism of LbGp in the treatment of H1N1-induced viral pneumonia includes reducing the viral load in lung, regulating the phenotype of pulmonary macrophages, and inhibiting excessive inflammation. In conclusion, LbGp exhibits potential curative effects against H1N1-induced viral pneumonia in mice, and these effects are associated with its good immuno-regulatory and antiviral activities. • LbGp can inhibit IAV infection, its antiviral activity is related to blocking the process of virus attachment and entry. • LbGp has immunomodulatory effects on macrophages by regulating NF-κB related signaling pathways and phenotype. • LbGp alleviates H1N1 induced viral pneumonia in mice. • LbGp has curative effects on pneumonia caused by H1N1, which are related to its immune regulation and antiviral activity. [ABSTRACT FROM AUTHOR]

[Display omitted] The aim of this study was to improve the bioavailability of polymyxin B (PMB) in pulmonary nebulized drug delivery. To this end, we developed a nano-delivery system that penetrates the mucus barrier of the lung. Hydrophilic hyaluronic acid (HA) was combined with a water-in-oil system containing a poly (lactic acid)-glycolic acid copolymer of PMB to prepare HA@PLGA-PMB nanoparticles (NPs) with good surface properties. HA@PLGA-PMB NPs with suitable electrical properties, particle size, and good hydrophilicity prevented strong interactions between the NPs and mucus, thereby allowing more drugs to enter deeper into the lung. Compared to the free drug PMB, NPs had more than 2-fold higher mucus penetration efficiency in vitro and better delivery to infected alveolar cells during in vivo nebulization. NPs had better biocompatibility, which further reduced the drug toxicity. More importantly, NPs showed better antimicrobial therapeutic efficacy in the treatment of lung infections in mice. These findings may provide support for the clinical application of nebulized pulmonary antibiotics. [ABSTRACT FROM AUTHOR]

Papaya fruit easily decays and prematurely senescence after harvest. Studies have shown that adding ascorbic acid to chitosan can improve postharvest quality and extend the shelf life of coated fruits. Therefore, the effect of 1.5% (w/v) ascorbic acid (AsA), 1.0% (w/v) chitosan (CTS), and 1.5% (w/v) ascorbic acid + 1.0% (w/v) chitosan (AsA + CTS) treatment on the storage quality of papaya fruits was studied. The results showed that AsA + CTS treatment reduced the weight loss, malondialdehyde, and hydrogen peroxide content of papaya fruit. AsA + CTS treatment improved the antioxidant capacity of papaya fruits by increasing the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase), soluble sugar and total phenol content, as well as by maintaining color and delaying senescence of fruits. AsA + CTS treatment also inhibited fruit softening by reducing cell-wall- degrading enzymes activities and by encoding gene transcript levels for cellulase, polygalacturonase, pectin methylesterase, and β-galactosidase. In summary, AsA + CTS treatment was an effective technique for maintaining the postharvest storage quality of papaya fruits. • Ascorbic acid (AsA) and chitosan (CTS) combined treated fruits have the best fruit quality. • The weight loss, malondialdehyde, and hydrogen peroxide content were reduced by AsA + CTS treatment of papaya fruits. • Antioxidant enzyme activities, soluble sugar and total phenol content were increased by AsA + CTS treatment of papaya fruits. • The AsA + CTS treatment maintaining color and delaying senescence of fruits. • The AsA + CTS treatment also inhibited fruit softening during the storage times. [ABSTRACT FROM AUTHOR]