49 research outputs found

    Preliminary study of improving immune tolerance in vivo of bioprosthetic heart valves through a novel antigenic removal method

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    The durability of bioprosthetic heart valves is always compromised by the inherent antigenicity of biomaterials. Decellularization has been a promising approach to reducing the immunogenicity of biological valves. However, current methods are insufficient in eliminating all immunogenicity from the biomaterials, necessitating the exploration of novel techniques. In this study, we investigated using a novel detergent, fatty alcohol polyoxyethylene ether sodium sulfate (AES), to remove antigens from bovine pericardium. Our results demonstrated that AES treatment achieved a higher pericardial antigen removal rate than traditional detergent treatments while preserving the mechanical properties and biocompatibility of the biomaterials. Moreover, we observed excellent immune tolerance in the in vivo rat model. Overall, our findings suggest that AES treatment is a promising method for preparing biological valves with ideal clinical application prospects

    Molecular Dynamics Study on the Aggregation Behavior of Triton X Micelles with Different PEO Chain Lengths in Aqueous Solution

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    The aggregation structure of Triton X (TX) amphiphilic molecules in aqueous solution plays an important role in determining the various properties and applications of surfactant solutions. In this paper, the properties of micelles formed by TX-5, TX-114, and TX-100 molecules with different poly(ethylene oxide) (PEO) chain lengths in TX series of nonionic surfactants were studied via molecular dynamics (MD) simulation. The structural characteristics of three micelles were analyzed at the molecular level, including the shape and size of micelles, the solvent accessible surface area, the radial distribution function, the micelle configuration, and the hydration numbers. With the increase of PEO chain length, the micelle size and solvent accessible surface area also increase. The distribution probability of the polar head oxygen atoms on the surface of the TX-100 micelle is higher than that in the TX-5 or TX-114 micelle. In particular, the tail quaternary carbon atoms in the hydrophobic region are mainly located at the micelle exterior. For TX-5, TX-114, and TX-100 micelles, the interactions between micelles and water molecules are also quite different. These structures and comparisons at the molecular level contribute to the further understanding of the aggregation and applications of TX series surfactants

    Efficient production of ethylene glycol from cellulose over Co@C catalysts combined with tungstic acid

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    Catalytic conversion of renewable cellulose, instead of fossil resources, to high-value ethylene glycol (EG) is of great significance for reducing considerable worries regarding the energy problem. However, the EG production from cellulose is dependent on Ni and Ru based catalysts. Herein, encapsulated Co@C catalyst was firstly applied for EG production from cellulose combined with tungstic acid (TA). The mixing of the two catalysts in different ratios was compared and well-controlled, and the highest 67.3% yield of EG can be achieved. TA is used mainly to promote both the cellulose hydrolysis and the retro-aldol reaction of glucose to glycolaldehyde. Co@C catalysts are responsible for the hydrogenation of glycolaldehyde to EG. Compared with traditional noble metals and composite catalysts, the inexpensive and easily synthesized Co@C catalysts could greatly reduce the cost of production of EG. The Co@C catalysts encapsulated with outside graphene layers can keep high stability for at least 6 runs

    Selective Hydrogenolysis of 5-Hydroxymethylfurfural to 2-Hexanol over Au/ZrO2 Catalysts

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    2-Hexanol (2-HOL) is a versatile biomass-derived platform molecule for synthesis of liquid transportation fuels, lubricants, or detergents. Herein, a one-step preparation of 2-HOL using 5-hydroxymethylfurfural (HMF) as a substrate was reported for the first time. Several Au-based catalysts supported on different metal oxides were prepared to explore the relationship between carrier and catalytic activity. The results showed that the highest 2-HOL yield of 65.8 % was obtained at complete HMF conversion over the 5 %Au/ZrO2 catalyst. The 5 %Au/ZrO2 catalyst exhibited excellent durability after five consecutive recycling runs, while confirming its remarkable ring-opening hydrogenolysis on other biomass-derived furanics, furfural, with a total yield of 1-pentanol and 2-pentanol of 67.4 %. The distinguished ring-opening hydrogenolysis performance of the Au/ZrO2 catalyst originated from a synergistic effect between the interfacial Au-O-Zr oxygen vacancies-induced Lewis acidic sites (activating C-OH/C=O bonds) and metallic Au (activating H-2). This work provides a possibility for producing 2-HOL from HMF with high yield, expanding the sustainable application of lignocellulosic biomass

    Tandem Conversion of Fructose to 2,5-Dimethylfuran with the Aid of Ionic Liquids

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    Biomass-derived 2,5-dimethylfuran (DMF) is an ideal, renewable gasoline additive, and its production with high productivity is highly desirable. A continuous production route was developed to yield DMF from fructose via a tandem strategy, where dehydration catalysts (HY zeolite and niobium phosphate) assisted by 1-butyl-3-methylimidazolium chloride ([BMim] Cl) and hydro-deoxygenation (HDO) catalyst Cu-Ru/C were integrated into one reaction system with gamma-butyrolactone (GBL) as the mobile phase. Optimum conditions, such as temperature, H-2 pressure, weight hourly space velocity, and [BMim]Cl concentration, were investigated systematically, with an initial HDO study by using 5-hydroxymethylfurfural (HMF) as substrate and subsequent tandem dehydration and HDO to produce DMF with fructose as substrate. Among the conditions, the highest yield of DMF at 55.2% was gained by niobium phosphate and Cu-Ru/C, with the aid of [BMim] Cl in a fixed bed. Meanwhile, [BMim]Cl facilitated fructose dehydration to HMF and also mediated HDO of the resultant HMF by stabilization, which was clarified by H-1 NMR and FTIR spectroscopy. Finally, the fact that carbon deposit led to catalyst deactivation was examined thoroughly via a series of characterization techniques. This work achieved continuous DMF production from fructose and laid a foundation for future possible amplification of DMF
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