Rapid Quantification of Bioactive Lentinan with an Aniline Blue Fluorescent Method

Lentinan is a clinically approved immune modulator and its anticancer and immunomodulatory bioactivity is found to be dependent on its triple helical conformation. Therefore, the development of rapid and convenient method for determination of bioactive lentinan with triple helical conformation holds great promise for the quality control of lentinan healthy products. In this work, an aniline blue fluorescent method was optimized and established to accurately and rapidly detect bioactive lentinan. In the presence of lentinan, the fluorescence intensity of aniline blue with 404 nm excitation and 492 nm emission dramatically enhanced within 15 min in pH 10 glycine-NaOH buffer solution, which allowed the analysis of lentinan in a very simple and fast manner. The method allowed for the sensitive determination of lentinan in the range of 1 to 60 μg/mL with a detection limit of 0.25 μg/mL. Notably, the protocol exhibited excellent selectivity for the determination of triple helical lentinan over other saccharides. The method was successfully applied to the detection of bioactive lentinan in health tonic solution, which demonstrated the method had great potential for quality control of lentinan contained products.

Functional verification of the diphtheria toxin A gene in a recombinant system

Diphtheria toxin A （DTA）, a segment of the diphtheria toxin （tox）, inhibits protein synthesis in cells. When released from a cell, DTA is nontoxic and cannot enter other cells independently without the help of diphtheria toxin B. In this study, we artificially synthesized the DTA gene sequence and cloned it into pEGFP-N1 to generate the recombinant vector pEGFP-N1-DTA. This recombinant vector was then transfected into 293T cells to observe the effect of DTA protein expression on enhanced green fluorescent protein （EGFP） protein expression and the proliferation of 293T cells. After 48 h, high levels of EGFP expression were seen in control pEGFP-Nl-transfected cells, whereas very low levels were seen in cells transfected with pEGFP-N1-DTA. Reverse transcription polymerase chain reaction confirmed the expression of the DTA gene in cells transfected with pEGFP-N^-DTA. Further, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （M-I-I-） assay revealed a significant difference in cell proliferation between the control group and the pEGFP-N1-DTA-transfected group. Using the expression of EGFP expression as an indicator, this study revealed that DTA expression can inhibit intracellular protein synthesis and cell proliferation.

Locally generalised multi-agent reinforcement learning for demand and capacity balancing with customised neural networks

Reinforcement Learning(RL)techniques are being studied to solve the Demand and Capacity Balancing(DCB)problems to fully exploit their computational performance.A locally gen-eralised Multi-Agent Reinforcement Learning(MARL)for real-world DCB problems is proposed.The proposed method can deploy trained agents directly to unseen scenarios in a specific Air Traffic Flow Management(ATFM)region to quickly obtain a satisfactory solution.In this method,agents of all flights in a scenario form a multi-agent decision-making system based on partial observation.The trained agent with the customised neural network can be deployed directly on the corresponding flight,allowing it to solve the DCB problem jointly.A cooperation coefficient is introduced in the reward function,which is used to adjust the agent’s cooperation preference in a multi-agent system,thereby controlling the distribution of flight delay time allocation.A multi-iteration mechanism is designed for the DCB decision-making framework to deal with problems arising from non-stationarity in MARL and to ensure that all hotspots are eliminated.Experiments based on large-scale high-complexity real-world scenarios are conducted to verify the effectiveness and efficiency of the method.From a statis-tical point of view,it is proven that the proposed method is generalised within the scope of the flights and sectors of interest,and its optimisation performance outperforms the standard computer-assisted slot allocation and state-of-the-art RL-based DCB methods.The sensitivity analysis preliminarily reveals the effect of the cooperation coefficient on delay time allocation.

Fabricating PdCe/OMS-2 catalysts with boosted low-temperature activity for toluene deep degradation

Porous cryptomelane-type octahedral molecular sieve(OMS-2)with mixed Mn valence and abundant lattice oxygen species has attracted much attention in volatile organic compounds(VOC)catalytic elimination.However,complete conversion of arene over OMS-2 catalysts at relatively low temperature is still a challenge due to its limited crystal structure and inferior stability.Here,a series of PdCe/OMS-2 catalysts with different Pd/Ce molar ratios was fabricated by a facile impregnation method and the physicochemical properties of which were extensively characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HR-TEM),B runauer-Emmett-Teller(BET)method,X-ray fluorescence(XRF),X-ray photoelectron spectroscopy(XPS),temperature programmed reduction of H2(H2-TPR),Raman,In situ diffused reflectance infrared Fourier transform spectra(DRIFTS),and density functional theory(DFT)calculations.Results show that the total conversion of toluene can be achieved at 207℃ over PdCe2 with apparent activation energy as low as 62.6 kJ/mol.The strong synergistic effect between Pd and Ce remarkably boosts the catalytic activity of OMS-2,attributed to the abundant Mn^(3+)-O bands and active surface oxygen species.DFT results reveal that oxygen vacancy can be formed over PdCe2 much easily than that of Pd/OMS-2 and Ce/OMS-2 with the oxygen vacancy formation energy of2.42,2.83 and 2.68 eV,respectively.Simply increasing the Pd content cannot promote the catalytic activity although PdO is a critical active center in toluene oxidation.Oxygen vacancy attributed to the integrative effect of Pd,Ce and Mn species plays a promine nt role over prepared catalysts in toluene activation process.The findings reported in this work showed new insights into the designing of highly efficient OMS-2catalysts for VOC deep oxidation by tuning oxygen vacancy concentration.

Myeloid-derived suppressor cells promote B-cell production of IgA in a TNFR2-dependent manner

Myeloid-derived suppressor cells(MDSCs)are well known for their capacity to suppress antitumor T-cell responses,but their effects on B-cell function and antibody production remain unclear.Here,we found that MDSCs that accumulated around the germinal center in the spleen of tumor-bearing mice co-located with B cells.In the presence of MDSCs,the antibody reaction to a surrogate antigen was significantly enhanced in mice,especially the immunoglobulin(Ig)A subtype.Co-culture with MDSCs promoted both proliferation and differentiation of B cells into IgA-producing plasma cells in vitro.Interestingly,the cross talk between MDSCs and B cells required cell-cell contact.MDSCs from tumor necrosis factor receptor(TNFR)2^(−/−)mice,but not from TNFR1^(−/−)mice,failed to promote B-cell responses.Further investigation suggested that interleukin-10 and transforming growth factor-β1 were crucial for the MDSC-mediated promotion of IgA responses.These results demonstrate a novel mechanism of MDSC-mediated immune regulation during tumor growth.