基于RDEF标准的干涉测量数据编帧实现方法

干涉测量数据格式不兼容限制了不同机构间的交互支持能力,难以充分发挥甚长基线干涉测量(very long baseline interferometry,VLBI)的技术潜能。基于RDEF(raw data exchange format)标准研究了干涉测量数据格式的实现方法,给出了数据编帧和数据传输2个关键模块的实现方案。实验结果表明,该方法能够实现干涉测量数据的实时编帧和存储,格式符合RDEF标准。该方法已应用于我国新建深空站中的干涉测量数字终端系统中,提高了我国新建深空站参与国际合作的能力。     

抗赤星病烟草的防卫基因的表达与基因组DNA结构的变化

用赤星病菌（Ａｌｔｅｒｎａｒｉａ ａｌｔｅｍａｔａ）毒性菌株产生的ＡＴ毒素诱导烟草,可使寄主获得对赤星病８０．４％的系统抗性,比病菌弱毒株ＴＢＡ１６孢子诱导的效果高约２０％。烟草品种ＮＣ８９心叶叶碟在含ＡＴ毒素６０％和７０％的ＭＳ培养基上经２轮胁迫筛选和植株再生,得到抗病品系ＮＣ８９－ＴＴ。用５种防卫基因的ｃＤＮＡ探针检测了不诱导、受ＡＴ毒素诱导、受病菌弱毒株激发子诱导的ＮＣ８９和诱导与不诱导的ＮＣ８９－ＴＴ第４代植株５种基因的转录活性,结果表明,苯丙氨酸氨裂解酶（ＰＡＬ）基因在ＮＣ８９中不能组成型表达,可被ＡＴ毒素诱导激活,但不受激发子诱导;病程相关蛋白（ＰＲ蛋白）ＰＲ－ｌａ、查尔酮合成酶（ＣＨＳ）、脂氧合酶（ＬＯＸ）基因在ＮＣ８９中表现为诱导转录或诱导后转录活性增强;这４种基因都在ＮＣ８９－ＴＴ中组成型表达     

基于运放的电流模式滤波电路TT结构分析

本文提出了以基于运放Op-Amp的电流积分器为基础,构成有源RC电流滤波电路MOSFET－C（TT）结构。对这种电流模式TT结构进行了深入的理论研究,并利用PSPICE通用模拟电路程序,对其输出电压幅频特性和相频特性进行了仿真分析。得出了几点实用的结论。     

Effect of processing and food matrix on calcium and phosphorous bioavailability from milk-based fruit beverages in Caco-2 cells

Calcium and phosphorus bioavailability from different milk-based (whole milk, skimmed milk and soya milk) fruit beverages as affected by thermal treatment (TT) and high-pressure processing (HPP) was determined by means of the paired in vitro gastrointestinal digestion (solubility method)/Caco-2 cell model. Ca bioaccessibility was significantly higher in HPP (98.4% ± 1.6%) versus TT (91.3% ± 1.9%), but Ca bioavailability was equal in all different matrixes independently of the processing treatment used. HPP samples improved P bioaccessibility (98.7% ± 2.5% versus 87.3% ± 2.2%) and P bioavailability by Caco-2 cells versus TT samples—soya milk- and whole milk-based beverages being the samples with the highest bioavailability values (56.8% ± 1.3% and 40.1% ± 9.9% versus 15.0% ± 2.1% and 16.8% ± 2.8%, respectively). Therefore, HPP improves Ca and P bioaccessibility, and P bioavailability versus TT samples, and can be used as an alternative to TT in the manufacture of functional foods with improved nutritional value and health benefits.     

Endpoint Visual Detection of Three Genetically Modified Rice Events by Loop-Mediated Isothermal Amplification

Genetically modified (GM) rice KMD1, TT51-1, and KF6 are three of the most well known transgenic Bt rice lines in China. A rapid and sensitive molecular assay for risk assessment of GM rice is needed. Polymerase chain reaction (PCR), currently the most common method for detecting genetically modified organisms, requires temperature cycling and relatively complex procedures. Here we developed a visual and rapid loop-mediated isothermal amplification (LAMP) method to amplify three GM rice event-specific junction sequences. Target DNA was amplified and visualized by two indicators (SYBR green or hydroxy naphthol blue [HNB]) within 60 min at an isothermal temperature of 63 °C. Different kinds of plants were selected to ensure the specificity of detection and the results of the non-target samples were negative, indicating that the primer sets for the three GM rice varieties had good levels of specificity. The sensitivity of LAMP, with detection limits at low concentration levels (0.01%–0.005% GM), was 10- to 100-fold greater than that of conventional PCR. Additionally, the LAMP assay coupled with an indicator (SYBR green or HNB) facilitated analysis. These findings revealed that the rapid detection method was suitable as a simple field-based test to determine the status of GM crops.     

A群奈瑟脑膜炎球菌荚膜多糖-破伤风类毒素结合物的制备及其工艺稳定性

目的按初步确定的工艺,制备A群奈瑟脑膜炎球菌荚膜多糖(Group A Neisseria meningococcus capsular polysac charide,GAMP)与破伤风类毒素(Tetanus toxoid,TT)的结合物,通过监测关键工艺参数,分析该工艺的稳定性。方法制备8批GAMP-TT结合物,经Sepharose4FF柱层析纯化后,进行各项生化鉴定,采用双向免疫扩散试验检测其抗原性,以结合物皮下免疫小鼠,ELISA检测小鼠血清中抗GAMP及抗TT IgG抗体水平。结果制备的8批结合物工艺关键参数较稳定,均保持GAMP抗原特异性;免疫小鼠后,均可诱生较高水平的血清抗GAMP IgG抗体,并可诱生免疫加强应答。结论该制备工艺稳定,为GAMP-TT结合疫苗的研制提供了参考。     

转基因大米TT51-1品系精准定量检测方法的比较研究

基于大米蔗糖磷酸合成酶(SPS)基因和TT51-1品系特异性基因序列筛选适用于数字PCR的内、外源基因特异性引物探针并建立转基因大米TT51-1品系的双重数字PCR定量方法。其定量的绝对灵敏度和相对灵敏度分别达2 copies/μL和0.1%。当样品中TT51-1转基因大米成分含量低至0.1%时,6次定量值的相对标准偏差在7.30%~18.63%之间,偏差在-8.77%~9.62%之间,精密度和稳定性均较为理想,而同样的引物探针所建立的实时荧光PCR方法定量的相对灵敏度仅达到1%。为促进该方法的标准化应用,将微滴式数字PCR平台上建立的定量方法在芯片式数字PCR平台上进行室内验证,结果表明该方法的定量精密度和准确性符合要求。该方法可应用于大米、稻谷及其初加工产品中TT51-1转基因大米成分的精准定量检测。     

航天测控技术及其发展方向

给出了航天测控的一般定义及其技术范畴,介绍了国际上通用的航天测控标准及其演化过程;分析了深空测控通信中面临的信号损耗、时延以及难以实现高精度连续测轨等问题;介绍了美国深空测控通信网的地理分布、组成部分及使用设备,研究了美国深空网在信号覆盖、遥控能力、遥测能力及轨道测量方面的技术特点,总结了深空网的发展方向。     

淡议道路照明安全运行的防护措施

根据《城市道路照明设计标准》CJJ 45-2006,J 627-2006第6.1.9条:"道路照明配电系统的接地形式宜采用TN-S系统或TT系统,金属灯杆及构件、灯具外壳、配电及控制箱屏等的外露可导电部分,应进行保护接地,并应符合国家现行相关标准的要求。"笔者分析了道路照明安全运行的防电击措施,提出其较可行的防护措施———即TT系统。     

道路照明供电系统中接地制式的选择

结合电路模型,从两个方面分析了采用TN-S接地制式的市政道路照明供电系统的安全隐患。提出采用TT接地制式的合理性。当发生接地故障时,TT接地制式由于缺少PE线提供的通路,故障电压无法蔓延至处于室外的道路照明灯杆。