牛磺酸对运动能力影响的研究进展

牛磺酸是一种含硫条件性必需氨基酸,是人和动物机体内不可缺少的一种生理活性物质。牛磺酸对于机体的运动能力有着重要的影响,本文在介绍牛磺酸的代谢过程及生理作用的基础上,对目前国内外关于补充牛磺酸与提高人体的运动能力的关系、牛磺酸的安全性及副作用等方面研究情况做一综述。牛磺酸已开发成颇具潜力的抗运动性疲劳的营养补充剂,同时在医药、卫生、保健等领域里也具有广泛商业价值和社会价值。     

基于静电喷雾法萝卜硫素微胶囊的制备与表征

使用静电喷雾法制备不同壁材的萝卜硫素（sulforaphane，SF）微胶囊，通过表征微胶囊表面形貌、分子间相互作用、热行为、体外释放情况以及在高温下的贮存稳定性，研究食品级聚合物对SF的微胶囊化作用，从而筛选出适合静电喷雾包封SF的壁材。结果表明，微胶囊平均粒径在427.80～1 857.04 nm之间，呈球状，表面光滑。相比壳聚糖，玉米醇溶蛋白（Zein）和明胶（gelatin，Gel）是更有效的SF递送载体，Zein-SF、Gel-SF的包封率分别为（95.83±2.37）%、（95.11±2.82）%。傅里叶变换红外光谱确认了SF微胶囊中SF的存在；热重分析结果显示SF微胶囊在300 ℃的高温下才大量降解，有较高的热稳定性。SF微胶囊在模拟胃肠液和食物基质的最终释放率在80%～90%之间，具有良好的胃肠溶解和释放性能；同时，微胶囊化处理后的SF耐热性显著提高。本研究结果有助于进一步开发SF递送载体，促进其产业化应用。     

Ion migration behavior and its interaction with sintering environment in cation conductor during flash sintering

Flash sintering has been reported in various ceramics. Nevertheless, anion and cation conductors exhibit different flash-sintering behaviors, and the interaction mechanism between the conductive species and the sintering environment has remained unclear. Herein, we report the flash-sintering phenomena of a typical cation conductor, Na₃Zr₂(SiO₄)₂(PO₄) with anode region surrounded by air and NaNO₃ environments. The results prove that the ionic behavior and joule heating distribution can be controlled by changing the electrode environment. Four possible scenarios describing the ion migration behavior and interaction with the environment are proposed for providing a guidance for controlling the ion interaction behavior during flash sintering.     

Oxidation behavior and electrical properties of metal interconnects with Ce-doped Ni–Mn spinel coatings

To improve the high-temperature oxidation resistance and electrical conductivity of ferritic stainless steels, protective Ce-doped NiMn₂O₄ spinel coatings were fabricated on the surface of SUS430 steel by electrophoretic deposition (EPD). The phase structure and microstructure of Ce-doped NiMn₂O₄ in both powder and coating forms were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The high-temperature oxidation of the NiMn₂O₄ spinel coating before and after Ce doping in the air at 800 °C for 168 h was studied by weight gain experiments. The area-specific resistance (ASR) of coatings was measured by a standard four-probe method. It was found that the Ce-doped NiMn₂O₄ spinel powder displayed a stable structure, high crystallinity, fine grain size, and decreased agglomeration when the Ce content was fixed at 0.05 mol?L^?1. The oxidation kinetics of NiMn₂O₄-coated SUS430 steel before and after Ce doping obeyed a parabolic law with parabolic rate constants of 4.58 × 10^?15 g² cm^?4 s^?1 and 1.83 × 10^?15 g² cm^?4 s^?1, respectively. When oxidized at 800 °C for 50 h, the ASR value of the coated samples before and after Ce doping stabilized at about 15.2 mΩ?cm² and 14.5 mΩ?cm², respectively. This work demonstrated that the Ce-doped NiMn₂O₄ spinel coating improved the high-temperature oxidation resistance and the electrical conductivity of metal interconnects.     

双联斜齿轮斜齿脱模机构及改进型三板模设计

依据双联斜齿轮和单斜齿轮2个塑件同模注塑的需要,以双联斜齿轮塑件的模腔设计为中心,设计了一副一模两腔点浇口多板模注塑模具。模具中,双联齿轮的上、下斜齿轮斜齿分别使用2个可旋转斜齿轮成型件进行成型;单斜齿轮使用1个可旋转斜齿轮成型件进行成型。3个斜齿成型件设置成转动型成型件,依靠塑件的移动以驱动斜齿成型件转动,达到塑件斜齿脱模的目的;塑件的脱模移动有两种动力来源,一种是模具模板的打开驱动,一种是使用推管顶出驱动。模具为一种改进型三板模结构,定模侧增加了流道板,动模侧增加了垫板,从而可以实现模具的4次开模;4次开模动作中,2次用于流道废料的脱模,1次用于流道镶件的先抽芯驱动,1次用于模腔的打开和双联斜齿轮上斜齿轮的旋转脱模驱动。     

Designing amorphous formulations of polyphenols with naringin by spray-drying for enhanced solubility and permeability

Naringin (NAR), a major flavanone (FVA) glycoside, is a component of food mainly obtained from grapefruit. We used NAR as a food additive to improve the solubility and permeability of hydrophobic polyphenols used as supplements in the food industry. The spray-dried particles (SDPs) of NAR alone show an amorphous state with a glass transition temperature (T_g) at 93.2 °C. SDPs of hydrophobic polyphenols, such as flavone (FVO), quercetin (QCT), naringenin (NRG), and resveratrol (RVT) were prepared by adding varying amounts of NAR. All SDPs of hydrophobic polyphenols with added NAR were in an amorphous state with a single T_g, but SDPs of hydrophobic polyphenols without added NAR showed diffraction peaks derived from each crystal. The SDPs with NAR could keep an amorphous state after storage at a high humidity condition for one month, except for SDPs of RVT/NAR. SDPs with NAR enhanced the solubility of hydrophobic polyphenols, especially NRG solubility, which was enhanced more than 9 times compared to NRG crystal. The enhanced solubility resulted in the increased membrane permeability of NRG. The antioxidant effect of the hydrophobic NRG was also enhanced by the synergetic effect of NAR. The findings demonstrated that NAR could be used as a food additive to enhance the solubility and membrane permeability of hydrophobic polyphenols.