Diffusion of Selenium in Liquid-Phase Epitaxy–Grown Hg<Subscript>0.78</Subscript>Cd<Subscript>0.22</Subscript>Te

We present preliminary results on Se diffusion in liquid-phase epitaxy (LPE)–grown HgCdTe epilayers. The LPE Hg_0.78Cd_0.22Te samples were implanted with Se of 2.0 × 10¹⁴/cm² at 100 keV and annealed at 350–450°C in mercury saturated vapor. Secondary ion mass spectrometry (SIMS) profiles were obtained for each sample. From a Gaussian fit, we find that the Se diffusion coefficient D _Se is about 1–2 orders of magnitude smaller than that of arsenic. The as-implanted Se distribution is taken into account in case of small diffusion length in Gaussian fitting. The D _Se was found to satisfy the Arrhenius relationship .     

乳酸菌富硒及产胞外多糖条件的研究

试验以实验室保藏的6株乳酸菌为研究对象,筛选出最佳试验条件下富硒率和产胞外多糖含量最优的菌株,以期为生产富硒调味品提供一定的理论依据.通过测定其生长曲线确定各菌的加硒时间,对比6株乳酸菌在不同亚硒酸钠质量浓度下的颜色变化、富硒率变化和胞外多糖含量变化,选定鼠李糖乳杆菌作为最佳试验菌株;通过测定鼠李糖乳杆菌在不同培养时间...     

山东苍山县大蒜中硒含量测定

采用荧光分光光度法分别对山东省苍山县和济南产大蒜中硒含量进行了测定,结果显示,苍山县大蒜中的硒含量明显高于济南产大蒜。苍山县居民素有种蒜、食蒜习惯,因此长期摄食含硒高的大蒜可能与此地区胃癌发病率低有一定关系。     

Thermal expansion behavior and microstructure in bulk nanocrystalline selenium by thermomechanical analysis

Thermal expansion behavior of bulk nanocrystalline (NC) Se samples with a grain size range of 16–46 nm was studied by thermomechanical analysis (TMA) in the temperature range 290–373 K. Bulk NC Se samples were prepared by isothermally crystallizing the as-quenched bulk amorphous solid at 373–478 K. The glass transition and crystallization of the remaining amorphous Se in the partially crystallized samples were studied by TMA, and compared with the results of differential scanning calorimetry (DSC). The glass transition temperature, as determined from the thermal expansion behavior, was 308 K, 11 K lower than the value by DSC analysis. A structural densification phenomenon was observed in a grain growth process of an as-crystallized NC Se sample by TMA. It was found that the linear thermal expansion coefficient of the bulk NC Se sample increased with a reduction of grain size, from which the deduced thermal expansion coefficient of the interface decreased with the refinement of the grain size.     

黄豆发芽过程中Zn、Co和Se的富集及交互作用

本研究以黄豆发芽为手段,采用具有交互关联功能的均匀设计U10(103)表设计并实施了Zn、Co、Se三种人体微量元素在黄豆芽菜生长过程的生物富集实验,评价了芽菜样品的Zn、Co和Se富集量以及有机化富集量,研究了不同Zn、Co、Se外源浓度组间样品生物富集量与各元素外源浓度的回归关系,发现了各元素外源浓度对Zn、Co和Se富集的交互作用以及Zn、Co和Se的富集规律。结果表明：交互作用发生在芽菜生长后期（30 h后）,[Zn×Co]和[Co×Se]呈现协同作用,外源Se通过双重协同作用促进芽菜吸收Zn,[Zn×Se]和[Zn×Co×Se]呈现拮抗作用,外源Zn通过双重拮抗作用抑制芽菜对Se的吸收;芽菜生长前期（30 h前）元素的有机转化率低,元素的富集是以物理渗析吸收为主,生长后期（30 h后）则通过各元素外源浓度的交互作用产生有机化富集,综合评价结果表明处理方案3、6和9对获得富Zn、Co和Se的芽菜特别有效,特别是处理方案3（Zn2+、Co2+混合液：[Zn2+]=1200 μg/L,[Co2+]=30 μg/L;Se4+溶液：[Se4+]=180 μg/L）45 h的样品达到了最优综合Zn、Co和Se富集：Zn2+ =8.58 mg/kg,Co2+=63.10 μg/kg,Se4+=48.30 μg/kg,有机化率分别为Zn 49.50%,Co 25.94%,Se 56.25%,三个元素的富集总量基本同时达到了Zn、Co和Se在中国膳食指南中推荐摄入量,对于Zn、Co和Se多元富集健康蔬菜的生产实际具有直接的参考作用。     

硒多糖酸奶贮藏期间的理化特性研究

为研究硒多糖对酸奶4℃贮藏25d内理化特性的影响,将0.06%硒多糖添加到纯牛奶中通过乳酸菌发酵制得硒多糖酸奶,测定硒多糖酸奶和对照酸奶中持水力、酸度、乳酸菌及硒含量等指标。结果表明:低温贮藏5-25 d内,对照酸奶和硒多糖酸奶持水力比较稳定;当贮藏时间为第15 d时,硒多糖酸奶持水力显著高于对照酸奶(P<0.05)。酸度随着贮藏时间的延长而显著增加(P<0.05),硒多糖酸奶和对照酸奶之间酸度无明显差异性。乳酸菌数量于贮藏时间5-25d呈现明显下降趋势(P<0.05),硒多糖酸奶在贮藏时间1d、10d和15d时乳酸菌数量显著低于对照酸奶(P<0.05)。低温贮藏期间酸奶硒含量比较稳定,且硒多糖酸奶硒含量是对照酸奶的10倍左右。硒多糖能改善酸奶在贮藏期间的一些理化特性。     

电感耦合等离子体质谱法测定牛初乳粉中痕量硒的干扰探讨

目的 分析样品基体给检测结果造成的增敏效应影响,建立一种能消除待测样品中基体的干扰,从而准确测定痕量硒的电感耦合等离子体质谱的检测方法。方法 样品经硝酸消解后, 采用标准加入法,标准溶液加入的体积不大于待测液体积2%的前提下,在氦气模式下以元素特定质量数定性,以待测元素质谱信号与内标元素质谱信号的强度比与待测元素的浓度成正比进行定量分析。结果 样品基底对硒有增敏效果采用标准加入法能很好消除样品基底干扰,检测5种标准物质的硒含量均在标示值范围内。工作曲线相关系数达到0.998,精密度试验的相对标准偏差为3.2%。结论 该方法相对外标法能更准确对痕量硒进行定量,适合测定基底复杂存在干扰的样品,对相同或相近的样品可以共用相同工作曲线测定硒含量。     

Comparison of Selenium Nanoparticles and Sodium Selenite on the Alleviation of Early Atherosclerosis by Inhibiting Endothelial Dysfunction and Inflammation in Apolipoprotein E-Deficient Mice

Atherosclerosis and related cardiovascular diseases represent the greatest threats to human health, worldwide. Previous animal studies showed that selenium nanoparticles (SeNPs) and Na₂SeO₃ might have anti-atherosclerotic activity, but the underlying mechanisms are poorly elucidated. This study compared the anti-atherosclerotic activity of SeNPs stabilized with chitosan (CS-SeNPs) and Na₂SeO₃ and the related mechanism in a high-fat-diet-fed apolipoprotein E-deficient mouse model of atherosclerosis. The results showed that oral administration of both CS-SeNPs and Na₂SeO₃ (40 μg Se/kg/day) for 10 weeks significantly reduced atherosclerotic lesions in mouse aortae. Mechanistically, CS-SeNPs and Na₂SeO₃ not only alleviated vascular endothelial dysfunction, as evidenced by the increase of serum nitric oxide level and the decrease of aortic adhesion molecule expression, but also vascular inflammation, as evidenced by the decrease of macrophage recruitment as well as the expression of proinflammatory molecules. Importantly, these results were replicated within in-vivo experiments on the cultured human endothelial cell line EA.hy926. Overall, CS-SeNPs had a comparable effect with Na₂SeO₃ but might have more potential in atherosclerosis prevention due to its lower toxicity. Together, these results provide more insights into the mechanisms of selenium against atherosclerosis and further highlight the potential of selenium supplementation as a therapeutic strategy for atherosclerosis.     

超级微波-氢化物发生-ICP-OES法测定淤泥中的砷、硒、汞

为利用电感耦合等离子体光谱法（ICP-OES）实现排污沟表层淤泥中低含量元素的准确测定分析,利用超级微波进行样品前处理,提高样品消解效率;利用氢化物发生系统提升仪器灵敏度,联合ICP-OES技术实现淤泥中砷、硒、汞的在线分析。该方法可以降低样品消耗量和废液产出,节约预算成本。通过对上中下游淤泥成分物质的直接测定,结果表明各元素线性相关系数（R²）均大于 0.999,方法检出限为0.037 5~0.077 5 μg/L,精密度均低于3.54%,样本加标回收率在91.5%~98.3%。该分析方法具有操作简便、准确度好、灵敏度高等优点,对于可生成氢化物的痕量元素可以快速准确定量,为排水沟表层淤泥检测助力,也为环境样本低含量元素的应用检测技术提供了思路和借鉴。