Isolation, structural characterization and immunomodulatory activity on RAW264.7 cells of a novel exopolysaccharide of Dictyophora rubrovalvata.

Fungal polysaccharides have been explored by many for both structural studies and biological activities, but few studies have been done on the extracellular polysaccharides of Dictyophora rubrovalvata, so a new exopolysaccharide was isolated from Dictyophora rubrovalvata and its structure and its immunological activity were investigated. The crude exopolysaccharide (EPS) was purified by DEAE52 cellulose and Sephadex G-200 to obtain a new acidic polysaccharide (DR-EPS). DR-EPS (2.66 × 103 kDa) was consisted mainly of mannose, glucose, galactose and glucuronic acid with a molar ratio of 1: 0.86: 0.20: 0.01. In addition, DR-EPS increased the phagocytic activity of RAW264.7 cells up to 2.67 times of the blank control group. DR-EPS improved intracellular nucleic acid and glycogen metabolism as observed by AO and PAS staining. DR-EPS(40 µg/mL) promoted NO production up to 30.66 µmol, enhanced acid phosphatase (ACP) and superoxide dismutase (SOD) activities, with activity maxima of 660 U/gprot and 96.27 U/mgprot, respectively, and DR-EPS (160 µg / mL) significantly increased the lysozyme content as 2.73 times of the control group. The good immunological activity of extracellular polysaccharides of Dictyophora rubrovalvata provides directions for the use of fermentation broths.

Isolation and structural characterization of exopolysaccharide from the Cordyceps cicadae and the immunomodulatory activity on RAW264.7 cells.

A new exopolysaccharide component named as PC-EPS was isolated from Cordyceps cicadae, and its structure was determined. PC-EPS was identified to be constituted of mannose, glucose, and galactose (28.84:1:19.42), with an average molecular weight of 3.72 × 106  Da, according to the results of monosaccharide composition, Fourier transform infrared, nuclear magnetic resonance, periodate oxidation and Smith degradation, and methylation studies. According to structural characterization, PC-EPS's connection type was made up of →6) -α-d-Manp (1→, →2) -ß-d-Manp (1→, →4) -α-d-Manp (1→, →2) -α-d-Galf (1→, and →4) -α-d-Galp (1→. PC-EPS may significantly increase phagocytosis and RAW264.7 cell proliferation. Additionally, by boosting intracellular lysozyme, cellular acid phosphatase, and cellular superoxide dismutase enzyme concentrations, as well as by promoting the generation of cellular NO, it is the potential to regulate the immunological activity of RAW264.7 cells. Additionally, the effects of PC-EPS on RAW264.7 cells increased their capacities to create tumor necrosis factor-α and interleukin 6 cytokines, all of which suggested that PC-EPS had the potential to improve immunomodulatory activity.

Transcriptome analysis reveals key metabolic pathways and gene expression involving in cell wall polysaccharides-disassembling and postharvest fruit softening in custard apple (Annona squamosa L.).

This study aimed to investigate the effect of custard apple cell wall polysaccharides-disassembling on postharvest fruit softening and to explore its key metabolic pathways and gene expression. Custard apple fruit was stored at 15 ± 0.5 °C for 12 days, it was found that the decreased significantly in fruit firmness, contents of Na2CO3-soluble pectin, hemicellulose and cellulose, and the increased significantly in water-soluble pectin and CDTA-soluble pectin. The activities of cell wall-degrading relevant enzymes in fruit were improved significantly during storage, including cellulase, polygalacturonase, pectin methyl esterase, neutral xylanase, ß-galactosidase, and ß-D-glucosidase. The RNA sequencing results revealed 41,545 nonredundant unigenes and 7571 differentially expressed genes (DEGs) in custard apple fruit samples. Functional annotation and DEGs data revealed cell wall degradation potentially involved in starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, galactose metabolism, pentose and glucuronate interconversions. Specifically, two EG and six ß-Glc genes controlled the cellulose decomposition, and one ß-xyl and one GATU genes involved in the degradation of hemicellulose, and two PME, one Pel, and four PG genes were the major regulators of pectin disassembling. These results provide a molecular foundation for explaining fruit softening and extending shelf life of custard apple.

Trichoderma asperellum as a novel source to prepare chitooligosaccharides by enzymatic hydrolysis and its antimicrobial activity.

Chitooligosaccharides (COS), an important biological functional component, are mainly extracted from marine products, but its raw materials are currently facing challenges such as marine resources pollution and demineralization. This study aimed to explore Trichoderma asperellum as a novel source to prepare COS. The COS were prepared by the enzymatic degradation of chitosan from T. asperellum, and single factor experiment and orthogonal designs were used to optimize the enzymatic conditions for the preparation of COS. The composition of COS was performed by thin-layer chromatography, high-performance liquid chromatography, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The results showed that the degree of deacetylation of T. asperellum chitosan was 87.59%, and its enzymatic hydrolysis yield was 89.37 % under optimized extraction conditions. Moreover, the composition of COS in T. asperellum included chitotriose, chitopentaose, and chitohexaose. Compared with shrimp shells, COS prepared from T. asperellum showed stronger antibacterial properties against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella bacilli.

Older People's Usage Pattern, Satisfaction with Community Facility and Well-Being in Urban Old Districts.

Community facilities are an important element that supports older people's daily life and promotes their well-being. However, there is a dearth of comprehensive studies on the effect of planning and design of different types of community facilities on older people's usage patterns and satisfaction. This study aims to provide a framework to explore the relationship among the planning of community facilities, older people's usage and satisfaction level and well-being for different types of community facilities. Both spatial analysis and questionnaire survey (n = 497) methods are employed in this study. This study finds that commercial (89.34%), municipal (83.10%) and leisure (88.13%) facilities are most commonly used by older people. This study suggests that older people's frequency of visiting community facilities is mainly affected by the purpose of visiting a community facility. Planning and design quality of the community facility are found to be significantly associated with older people's satisfaction level with using a community facility. In addition, older people's higher satisfaction level and usage level of community facilities could increase their physical and psychological well-being. The findings of this study not only contribute to the knowledge gap of older people's usage and satisfaction with using community facilities but also suggest that planners should aim toward a better distribution of community facilities to improve older adults' well-being.

Granular flow of cylinder-like particles in a cylindrical hopper under external pressure based on DEM simulations.

Granular flow is widely found in nature or industrial production. Although the external driving force significantly affects the dynamic behavior of a granular system, a large number of numerical simulations have been conducted to study granular flows driven by gravity. In this study, a superquadric equation was used to construct spherical and cylindrical elements, and the flow processes of granular materials under external pressure were simulated by the discrete element method. To examine the validity of the DEM model, the Janssen effect of spherical particles, the static packing of cylindrical particles and the flow process of spherical particles under external pressure are simulated and compared with the previous experimental and theoretical results. Subsequently, the effects of blockiness, orifice diameter, and particle friction on the flow characteristics are investigated. Results show that the flow rate of spherical particles increases as the external pressure and opening diameter increase or the particle friction decreases. However, the flow rate of cylindrical particles decreases as the blockiness parameter increases, and the external pressure has little effect on the flow rate of the cylindrical particles when the blockiness parameter is greater than 4. Furthermore, the external pressure causes a change in the flow pattern of granular systems. In a gravity-driven granular flow, cylindrical particles appear in funnel flow, and spherical particles in both mass and funnel flows. In a pressure-driven granular flow, spherical particles appear in mass flow, and cylindrical particles in both mass and funnel flows. The critical height of the transition between mass and funnel flows decreases with increasing external pressure and eventually reaches a steady state. Meanwhile, the critical height increases with the blockiness parameter, which indicates that more cylindrical than spherical particles appear in funnel flow. Finally, the basic flow characteristics of granular materials under external pressure are further analyzed by the velocity uniformity index, the normal contact force between particles, and the bottom pressure. Overall, the numerical results are useful for understanding the changes in the flow characteristics of spherical and cylindrical granular materials under external pressure, and further provide guidance for the appropriate design and optimization of cylindrical hoppers.