Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

A smart nanoprobe based on luminescent terbium metal-organic framework coated gold nanorods for monitoring and photo-stimulated combined thermal-chemotherapy

Real-time monitoring and accurate treatment are of great significance for reducing the side effects during the cancer therapy.In this work,we rationally prepared a smart nanoprobe based on core-shell terbium metal-organic gramework(MOF)with highly effective photothermal conversion capacity and drug release efficiency under near-infrared light irradiation for real-time fluorescence imaging-guided multimodal therapy.The nanoprobe can achieve prominent photothermal therapy and controllable drug release,act as a fluorescence thermometer,and also real-time feedback of temperature is expected to be achieved.At the same time,the two-photon ligand design significantly improves the tissue penetration ability of the nanoprobe.Our work is expected to provide a reference for precise treatment and real-time monitoring of tumors and at the same time provide new ideas for the formulation of individualized treatment plans.

Performance evaluation of mechanical blossom thinning in trunk type pear orchard

In order to yield a marketable product,hand fruit thinning(HFT)has become the major but costly management practice in modern pear planting.Two kinds of new blossom thinners for pear blossom thinning were developed,which are tractor-mounted three arms blossom thinner(TTBT)and hand-held electric blossom thinner(HEBT).Four treatments for 24 trunk type‘Cuiguan’pear trees(7 years)were tested.They are TTBT combined with HFT,HEBT combined with HFT,hand blossom thinning(HBT)combined with HFT,and HFT only.Pear trees were divided into 4 groups equally.Four indexes were used to evaluate the test:flower reserve rate,fruit set rate,work efficiency and cost,fruit yield,and quality.Pear canopy was divided into the inner,middle,and outer 3 layers in the top view.20 inflorescence samples were selected for each layer.Field tests showed:there was no obvious difference in quality between mechanical blossom thinning and HBT,and the working stability of TTBT was higher than other treatments.Mechanical blossom thinning decreased the fruit set rate to a certain degree,but did not reduce the yield and quality of harvesting.TTBT could save 61.35%operation time compared with HFT,and the profitable area was 5845.76 m2.TTBT is suitable for large-scale sparse layer trunk-type pear orchards.HEBT could save 36.01%operation time compared with HFT,and the profitable area was 663.96 m2.HEBT is suitable for small and medium-sized trunk-type pear orchards.Blossom thinning can improve the average weight of high quality fruit and brix of sugar solids.

Humic acids derived from Leonardite to improve enzymatic activities and bioavailability of nutrients in a calcareous soil

Understanding the role of humic substances in soils is important for developing and utilizing organic fertilizers or soil amendments for sustainable agriculture.The objective of this study was to determine the effects of different fractions of humic acids derived from Leonardite on enzymatic activities and bioavailability of nutrients in a soil.The experiment was carried out by mixing different factions of humic acids with a soil and incubated for 70 d.The treatments included five factions of humic acids(HS1(low molecular weight),HS2(medium molecular weight)),HS3(large molecular weight,SED(sediment of fractions),HS(mixture of HS1,HS2,and HS3)),raw Leonardite(IM)and a control(no addition of humic acid).Experimental results showed that application of humic acids significantly improved acid and alkaline phosphatase activities,especially with HS1.Humic substances with high molecular weights significantly inhibit urease activity,and the optimal application rate was 600 kg/hm2 of humic substances with the high molecular weights.Concentrations of NH4+-N were decreased with increasing humus applications.All treatments(HSmix,HS1,HS2,HS3,IM,SED)did not affect the soil contents of Ca,although soil concentrations of K,P,Cu,Zn were increase significantly when small molecular weight humus(HS1)was applied.