磁制冷材料实用化研究进展

作为新一代的制冷技术,磁制冷技术已经进入到实用化研究阶段.主要评述了最有希望实用化的La-Fe-Si系磁制冷材料的研究进展,总结了材料的成相机制,以及热处理时间、温度、不同元素等因素对成相规律的影响,介绍了最新的制备加工工艺和氢化工艺,并讨论了 La-Fe-Si材料在磁制冷机中的应用进展,展望了磁制冷材料的发展趋势.     

联用技术测定富硒农产品中硒的形态研究进展

硒的营养功能与农产品硒的形态息息相关。联用技术作为元素形态分析的有效方法,近年来受到了人们广泛关注。对用联用技术测定富硒农产品中硒的形态研究现状及进展进行了综述,包括前处理技术、色谱分离技术和定量检测方法等3个方面。     

碳纳米管负载氢氧化镍修饰电极的制备及应用

采用表面滴涂结合循环伏安法制备了碳纳米管负载氢氧化镍修饰电极(Ni(OH)2/MWNT/CCE)。研究了该修饰电极对葡萄糖的电催化氧化性能。结果表明,该修饰电极对葡萄糖具有良好的电催化氧化活性。在优化条件下,安培法检测葡萄糖的线性范围为2.0×10-7～5.7×10-4 mol.L-1(r=0.999 9,s=2 786.5μA.(mmol.L-1)-1.cm-2)和5.7×10-4～2.7×10-3 mol.L-1(r=0.999 1,s=2 005.2μA.(mmol.L-1)-1.cm-2),检出限(3sb)为8.0×10-8 mol.L-1。该法已成功用于血清中葡萄糖含量的测定。     

A simple way to fabricate an aluminum sheet with superhydrophobic and self-cleaning properties

<正>A superhydrophobic aluminum sheet is fabricated via a hot water immersing process and subsequently surface modification with heptadecafluorodecyltrimethoxy-silane(HTMS).As revealed by the scan electron microscopy(SEM), X-ray diffraction(XRD),and Fourier-transform infrared spectrophotometer(FTIR) results,a rough pseudoboehmite film is formed on the aluminum sheet,and HTMS molecules are grafted on the film surface successfully.These two factors make the treated aluminum sheet present superhydrophobicity with a water contact angle larger than 160°and sliding angle less than 5°,and possess a self-cleaning property.Furthermore,the flexible superhydrophobic aluminum sheet could be pasted to a cylinder surface without destroying its superhydrophobicity.At the end,the effect of hot water treatment time on superhydrophobicity is investigated.     

聚-α-甲基苯乙烯热降解动力学研究

利用热分析技术(TG/DTG)对聚--甲基苯乙烯(PAMS)在氮气气氛下以不同升温速率为条件进行热降解动力学研究。研究结果表明:PAMS的热降解步骤为一步反应,在升温速率为10 ℃/min时,主要失重温度区间为302～343 ℃,热失重速率最大时温度为325 ℃。在同一温度下,随着升温速率的不断提高,主要降解温度向高温区移动。采用了Kissinger,Flynn-Wall-Ozawa及Coats-Redfern方法研究其动力学参数,确定了PAMS的降解活化能在160～220 kJ/mol之间、反应级数为一级。     

孔雀石绿-铁(Ⅱ)体系催化动力分光光度法测定雨水中微量过氧化氢

基于在pH 4.0的H₂SO₄介质中,Fe（Ⅱ）对H₂O₂氧化孔雀石绿褪色反应的催化作用,建立了一种在常温下测定H₂O2浓度的催化光度分析方法。在孔雀石绿吸收峰618nm波长处测得的吸光度降低值（△A）与过氧化氢浓度在0—50μmol·L^-1范围内呈线性相关,回归方程为△A=0.0171C+0.0191,检出限为1.0μmol·L^-1（s/n=3）。本法可以方便、快捷的用于雨水中微量过氧化氢的测定,结果满意。     

Using optical tweezers to investigate the specific single-interaction between apoA-I molecule and ABCA1 on living cells

We carry out in situ single-molecule measurements of the specific interaction between apolipoprotein A-I （apoA-I） and ATP binding cassette transporter A1 （ABCA1） on THP-1 cells. Single-molecule force spectroscopy shows that similar to normal apoA-I, the dysfunctional apoA-I from diabetes patients interacts with ABCA1 via two different binding sites on the cells. The strength of dysfunctional apoA-I binding to a high-capacity binding site is 26.5±4.9 pN. The minor direct apoA-I/ABCA1 binding strength is 56.7±4.1 pN. These results facilitate a pathological understanding of the mechanisms that underlie the specific interaction of aDoA-I and ABCA1 at the single-molecule level.     

The determination of the thickness and the optical dispersion property of gold film using spectroscopy of a surface plasmon in the frequency domain

We propose to use wavelength modulation approach,i.e.,the spectroscopy of a surface plasmon in the frequency domain,to characterize the optical dispersion property of gold film.Using this method,we determine the dispersion relationship of gold film in a wavelength range from 537.12 nm to 905.52 nm,and our results accord well with the reported results by other authors.This method is particularly suited for studying the optical dispersion properties of thin metal films,because a series of dielectric constants over a wide spectral range can be determined simultaneously via only a single scan of the incident angle,thereby avoiding the repeated measurements required when using the angular modulation approach.     

乳腺癌患者血清中TBX3的表达及其与临床病理特征的关系

目的探讨乳腺癌患者血清中TBX3的表达水平,探讨其与临床病理特征的关系。方法采用ELISA法检测142例乳腺癌患者、70例乳腺良性疾病患者和80例健康女性血清中TBX3的表达水平,并比较3者之间的差异,分析血清TBX3与乳腺癌患者年龄、月经状态、组织学分级、腋窝淋巴结及远处脏器转移、TNM分期以及雌激素受体（ER）、孕激素受体（PR）、人表皮生长因子受体2（Her-2）、细胞核增殖抗原（Ki-67）之间的相关性。结果142例乳腺癌患者血清TBX3水平为2.13（1.01-6.15）ng/ml,显著高于健康对照组[1.60（0.99-2.18）ng/ml]及良性对照组[1.58（0.71-3.18）ng/ml],差异均有统计学意义（P＜0.05或0.01）。血清TBX3表达水平与乳腺癌患者年龄、月经无关,但随着乳腺癌组织学级别增加、TNM分期进展、出现腋窝淋巴结及远处脏器转移而显著升高。此外,ER阳性及Her-2过表达者血清TBX3表达水平较ER阴性及Her-2低表达者明显升高,差异均有统计学意义（均P＜0.05）。Ki-67≥14%者与Ki-67＜14%者、PR阳性者与PR阴性者之间血清TBX3表达水平的差异均无统计学意义（均P＞0.05）。结论血清TBX3在乳腺癌患者血清中高表达,且与乳腺癌组织学分级、TNM分期、腋窝淋巴结及远处脏器转移、ER及Her-2密切相关,提示血清TBX3可能可以作为乳腺癌临床诊断、预后判断及随访监测的分子标记物。