呋喃西林代谢物荧光偏振免疫检测方法研究

利用新制备的抗体首次建立了呋喃西林代谢物氨基脲(SEM)的荧光偏振免疫分析(FPIA)方法.通过设计合成新的SEM半抗原CEPSEM(2-(4-((2-carbamoylhydrazono)methyl)phenoxy)acetic acid),偶联载体蛋白后免疫新西兰大白兔,制备了亲和力高、特异性好的多克隆抗体.结合新设计合成的荧光示踪物CEPSEM-HDF建立了SEM的FPIA方法.结果表明:在示踪物浓度为0.5 nmol/L,抗体稀释度为1/100的优化条件下,IC50为47.9 μg/L,检出限为8.3 μg/L,线性范围为15.8 ～145.7 μg/L.该方法特异性强(和其它相关兽药交叉反应小于0.1%),稳定性好(批内相对标准偏差小于2.5%,批间相对标准偏差小于6.3%).     

PET帮助医生了解酒精中毒症

 奈娃（图1右第1人）放下电话便向她的同事们宣布“35单位已运来”！周围的人顿时忙碌起来.奈娃是美国布鲁海汶国家实验室（BNL）正电子发射断层照相术医学部的研究人员,上述电话提醒她注意35毫居里的¹⁸FDG(¹⁸氟-萤光去氧葡萄糖)正从BNL的回旋加速器运往PETT。PETT是Positron emission Transaxial tomog-raphy的简称,即正电子发射断层照相术.其基本原理本刊前身“高能物理”1982年第3期上曾有介绍.     

直接投入固体粒子示踪物显示气流的研究

根据流体力学相关的理论知识,对采用固体粒子显示气流的跟随特性进行了理论分析,并选用碱式MgCO_3白色粉末作为直接投入物,用实验的方法进行了比较和验证,结果表明:直接投入MgCO_3粉末来显示气流具有良好的可视性和可记录性,可以很直观地观测到流体的流动状况,是一种有效的实验方法.     

荧光偏振免疫法测定水产品中的丁香酚

将丁香酚（Eul）与丙烯酸甲酯进行衍生化反应,合成了一种新型的丁香酚半抗原4-(4羟基-3-甲氨基苯基)-丁-2-烯酸（Eul-Aca）。采用活性酯法将丁香酚半抗原与乙二胺异硫氰酸荧光素（EDF）偶联,分别制备了同源和异源荧光示踪物。通过比较不同示踪物的抗体稀释度和灵敏度,优化反应时间等检测条件,建立了一种检测水产品中丁香酚的荧光偏振免疫分析法（FPIA）。结果表明：异源示踪物（Eul-AcaEDF）具有更优的检测灵敏度,抗体稀释度为1/200,反应时间仅需5 min。该方法的半抑制浓度（IC50）为11.2μg/L,检测线性范围为1.1～111.5μg/L,检出限（LOD）为0.24μg/L。实际样品中丁香酚的加标回收率为80.6%～107.4%,相对标准偏差（RSD）<15%。FPIA检测结果与气相色谱-质谱（GC-MS）法结果具有良好的一致性（r=0.993）,适用于水产品中丁香酚的残留检测。     

三聚氰胺单试剂荧光偏振免疫分析法

用三聚氰胺半抗原(MEL)与异硫氰酸荧光素乙二胺(EDF)反应合成了荧光示踪物MEL-EDF, 示踪物与三聚氰胺抗体反应得到稳定的单试剂免疫复合物, 考察了其结合动力学和置换动力学过程, 建立了一种三聚氰胺单试剂荧光偏振免疫分析方法(SR-FPIA). 该方法的检出限(LOD)为3.2 ng/mL, 半抑制浓度(IC₅₀)为157.1 ng/mL, 检测范围(IC₂₀~IC₈₀)为12.2~1012.4 ng/mL, 能够满足国家标准和国际食品法典委员会(CAC)对于食品中三聚氰胺最高残留限量的检测要求. 整个检测过程在15 min内完成, 并且单试剂免疫复合物在4℃下至少可稳定保存30 d以上. 本研究对开发三聚氰胺新型免疫检测方法具有重要意义.     

Instantaneous and time-averaged flow structures around a blunt double-cone with or without supersonic film cooling visualized via nano-tracer planar laser scattering

In a Mach 3.8 wind tunnel, both instantaneous and time-averaged flow structures of different scales around a blunt double-cone with or without supersonic film cooling were visualized via nano-tracer planar laser scattering (NPLS), which has a high spatiotemporal resolution. Three experimental cases with different injection mass flux rates were carried out. Many typical flow structures were clearly shown, such as shock waves, expansion fans, shear layers, mixing layers, and turbulent boundary layers. The analysis of two NPLS images with an interval of 5 μs revealed the temporal evolution characteristics of flow structures. With matched pressures, the laminar length of the mixing layer was longer than that in the case with a larger mass flux rate, but the full covered region was shorter. Structures like K-H (Kelvin-Helmholtz) vortices were clearly seen in both flows. Without injection, the flow was similar to the supersonic flow over a backward-facing step, and the structures were relatively simpler, and there was a longer laminar region. Large scale structures such as hairpin vortices were visualized. In addition, the results were compared in part with the schlieren images captured by others under similar conditions.