传染性胃肠炎病毒陕西分离株S基因主要抗原位点基因的克隆与序列分析

根据GenBank公布的猪传染性胃肠炎病毒S基因的序列,设计合成1对特异性引物,通过RT-PCR从用细胞增殖的TGEV病毒液中扩增编码S基因B、C抗原位点的基因片段,然后将获得的片段克隆至pMD18-T载体上,构建重组质粒。通过PCR、酶切和测序鉴定重组质粒,将测序结果与GenBank公布的21个相关序列进行多序列比较并绘制进化树。所克隆的TGEV陕西分离株S基因B、C抗原位点基因片段长度为765 bp,与参考毒株的核苷酸同源性为96.1%~99.9%。进化树分析表明,分离株与中国的H株、HN2002株、TS株,美国的Miller M60株、Miller M6株及英国的FS772株亲缘关系较近,与H株的亲缘关系最近。     

20世纪50年代以来云南民族识别研究回顾与反思

云南民族识别是我国民族识别工作的重要组成部分。采用文献研究法从初步实践和研究拓展的两个阶段,对云南民族识别的研究成果进行回顾和评价,从中发现：现有研究仅围绕＂云南民族识别调查成果＂的介绍展开,或是将其作为学术佐证资料。然而云南民族识别既是中国民族发展史上的重要历史事件,也是民族学学科建设的重要学术事件,有必要进一步挖掘和利用云南民族识别的研究价值,使其形成一项专题研究,为民族识别区域化研究作出反思     

外排泵基因在志贺菌分子分类中的应用

志贺菌属(Shigellae)是感染性腹泻的重要病原菌之一,志贺菌H24是临床多耐药株.在H24的分类过程中,发现血清分型和16S rRNA分类都有一定的局限性,16S rRNA不能直接把H24鉴定至种,通过分析H24外排泵基因emrE、cmr、ydhE、acrB基因序列信息,尝试利用外排泵的基因序列信息对志贺菌进行鉴定分类.结果表明,H24外排泵基因emrE、cmr、acrB和ydhE具有很强的进化保守性,未发现染色体上的外排泵基因在不同种属之间有明显的水平转移痕迹,对志贺菌仅用16S rRNA基因序列信息连属的分类都不能做到,但结合emrE和cmr的基因序列信息可直接将志贺菌鉴定到种,首次提出以外排泵基因为分子靶标对志贺菌和大肠杆菌进行快速分类的方法.     

The application to simplify the complicated power grid through adjacent two-node equivalent method

Most real power systems are not radial networks and evaluation of the stability often needs to establish electromagnetic transient simulation models. So the network equivalent is required first and foremost. The adjacent two-node equivalent method, which considers the coupling impedance between equivalent nodes, is used to realize the simplification and modeling to complex power grid. The analysis and simulation on both the HVDC system from Deyang to Baoji and a real extra-high voltage AC transmission system in South China shows that the static performance of the simulated system by using the adjacent two-node equivalent method is completely equivalent to the original one, as well as the performance of dynamic equivalent is in a satisfied level. Thus the transient system model simplified can be well established to support research of power grid’s security and stability.     

Evaluation of the microbiological safety and quality of Vietnamese <Emphasis Type="Italic">Pangasius hypophthalmus</Emphasis> during processing by a microbial assessment scheme in combination with a self-assessment questionnaire

Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.     

乡村景观模式与规划

新农村建设需要对乡村景观进行规划设计,有利于提高农民生活水平和农村经济发展水平,符合农村经济和生态发展需求。介绍了乡村景观现状,分析了乡村景观规划的重点模式,并探究了乡村景观规划的具体设计。      

Zirconium-Modified Activated Sludge as a Low-Cost Adsorbent for Phosphate Removal in Aqueous Solution

A highly effective zirconium-modified activated sludge (Zr(IV)-AS) adsorbent was prepared from activated sludge and applied to remove phosphate from aqueous solutions by batch and column experiments. Characterized results revealed that zirconium was successfully loaded onto the activated sludge (AS), and the specific surface area and pore volume were substantially improved after zirconium loading on the AS. Zr(IV)-AS exhibited a high adsorption affinity for phosphate and the maximum adsorption amount was 27.55 mg P·g^?1 at 25 °C. Adsorption isotherms of phosphate could be described by the Langmuir model, and the adsorption kinetics were well described by the pseudo-second-order model. Phosphate adsorption on Zr(IV)-AS increased monotonically with decreasing solution pH. The presence of SO₄^2? in water resulted in slightly decreased phosphate adsorption on the adsorbent even at a high concentration (25 mmol/L), and a greater influence of HCO₃^? on adsorption could be ascribed to the increased solution pH with the addition of the HCO₃^?. Column adsorption experimental results showed that the adsorbent has excellent phosphate adsorption properties and that the effluent can meet the requirement of phosphorus in the national wastewater discharge standard of China. Phosphate-saturated Zr(IV)-AS can be effectively desorbed in 0.1 mol L^?1 NaOH solution, and the regenerated adsorbent still possessed the high capacity. The adsorption between the adsorbent and the phosphate is due to the electrostatic interaction and anionic exchange at the surface of the Zr(IV)-AS. Furthermore, this approach provides a possibility of treating wastewater with waste and has the potential for industrial applications for the removal of phosphate from wastewater.     

Isolation and Characterization of the Tellurite-Reducing Photosynthetic Bacterium, <Emphasis Type="Italic">Rhodopseudomonas palustris</Emphasis> Strain TX618

A novel tellurite-resistant photosynthetic bacterium, Rhodopseudomonas palustris strain TX618, was isolated from wastewater and reduction of tellurite by this strain was investigated. The results showed that Rhodopseudomonas palustris strain TX618 could reduce tellurite to elemental tellurium, both anaerobically and aerobically. During anaerobic and illuminated growth, strain TX618 possessed a high-level resistance and removal efficiency to tellurite, that it could resist up to 180 mg/L Na₂TeO₃ in the medium and removed 91.9% of 90 mg/L Na₂TeO₃ over 8 days. The high efficiency in the removal of tellurite could sustain wide variations in pH (5.0–9.0), temperature (20–40 °C), light intensity (1500–3000 lx), and initial tellurium concentration (30–180 mg/L Na₂TeO₃). It could be observed by scanning electron micrograph (SEM), transmission electron micrograph (TEM), and X-ray diffraction (XRD) analysis that the cells suffered serious deformation due to the toxicity of tellurite, and the less toxic black precipaite (Te⁰) generated by bioreduction of tellurite mostly located in the central cytoplasm. This is the first study to observe that Rhodopseudomonas palustris can reduce tellurite to elemental tellurium, which will provide a new microbial species for bioremediation and biotransformation of toxic tellurite.     

基于时空信息比较的温室环境传感器故障识别

为了提高温室环境测控系统中传感器数据的准确性,针对温室环境参数变化的时间相关性和空间相似性特点,提出了一种基于主成分分析(Principal component analysis,PCA)的故障检测与基于时空信息比较的温室环境监测系统的传感器故障识别方法。首先利用基于PCA的传感器故障检测方法,通过监控统计量T2和SPE的变化实现传感器系统故障检测;再针对检测出故障的传感器节点,对该时刻传感器节点采用基于时空特性的节点信息比较实现不同传感器的故障识别。分别对比基于时间尺度、空间尺度、时空尺度的节点信息比较方法对传感器故障识别的影响进行了分析与试验验证,验证结果表明:基于PCA的传感器故障检测方法能够有效地实现对传感器系统故障的初步检测,提出的基于时空信息比较的传感器故障识别方法,融合考虑时间尺度和空间尺度的节点信息,能够有效地实现传感器具体故障定位;所建立的传感器故障识别方法检测正确率CDR为98.37%、平均虚警率FAR为1.72%,较传统的传感器故障识别方法检测正确率CDR提高了22.067个百分点,而平均虚警率FAR则降低了15.762个百分点,能够有效地保证故障诊断效率、提高故障诊断精度、降低虚警率,具有可靠性和准确性。     

青羊参凝乳剂提取及其对乳饼制作工艺的影响

以青羊参叶为原料,研究了其有效凝乳成分的提取方法,并在乳饼加工过程中进行了验证。结果表明,青羊参凝乳剂的最佳提取温度为4℃,最佳提取的液料比为20 mL/g,最佳提取溶液为10 mmol/L柠檬酸-磷酸缓冲液;与传统直接添加青羊参叶浸泡液的方法相比,使用青羊参凝乳剂制成的乳饼蛋白质回收率、脂肪回收率和乳饼得率均显著提升(P0.05);质构和微观结构显示,使用青羊参凝乳剂制作的乳饼具有更适宜的硬度和较高的粘着度,凝胶网络结构分布均匀。