Methodology for antibody preparation and detection of southern rice black-streaked dwarf virus

Southern rice black-streaked dwarf virus (SRBSDV) is a member of the genus Fijivirus of the family Reoviridae that causes a devastating disease in rice. Seven polypeptide fragments of the Putative uncharacterized protein (Pup) and the P10 proteins of SRBSDV were designed, synthesized, and used to immunize rabbits. Titers of polyclonal antibodies against the seven peptides were examined using indirect enzyme-linked immunosorbent assay (ELISA), and their specificities were investigated using western blotting. Indirect dot-immunobinding assay (DIBA) was also carried out at different dilutions against an antigen (rice extract). Antibody-1, which had the highest selectivity and titer, was then used to examine rice samples suspected of being infected with SRBSDV that were collected for over two years in different areas of China, using DIBA. Our results indicate that antibody-1 has the advantages of reliability, high sensitivity, and high specificity. Use of this antibody can help facilitate identification of the virus and its distribution in rice-growing areas where it causes significant problems.     

Identification and genomic analysis of two duck-origin Tembusu virus strains in southern China

Egg-laying duck flocks in Guangdong province, southern China, have been suffering a widely spreading infectious disease with abrupt egg drops and death since the winter of 2010. However, the causative pathogen was not known. We obtained two independent virus isolates named FS and JM from the diseased layer duck flocks and identified them as duck-origin Tembusu virus by PCR detection, sequencing the entire length of the open reading frames (ORFs). The two isolates FS and JM shared high sequence similarity to the isolates of duck-origin Tembusu virus that was first emerged in eastern China in April 2010. Blast analysis shows that the whole ORF sequences of FS and JM have the highest similarity (>99 %) to BYD-1(the first reported duck-origin Tembusu virus) and JS804 (the first reported goose-origin Tembusu virus), indicating that the full-length genomes were highly conserved in waterfowl-origin Tembusu viruses. The present study suggests that duck-origin Tembusu viruses have spread fast from eastern China to southern China, causing widely spreading infections. The high conservation of duck-origin Tembusu virus strains provides the genomic basis for choosing the strains for vaccine preparation for better protection against this new virus infection.     

MSCT孤立肺小结节的神经网络模型的应用研究分析

目的研究神经网络模型（SVM）在MSCT孤立肺小结节（SPN）良恶性判断中的应用。方法收集2000例经病理证实的SPN临床表现及影像学特征,采用SPSS13.0统计学软件将各观察指标进行多因素回归分析,与SPN病理相关指标作为SVM分析参数,对1500例进行训练,另对500例进行预测,对照病理结果分析。结果与病理对照,500例SVM中良性正确预测238（98.5%）例,错误预测4（1.5%）例;恶性正确预测250（97%）例,错误预测8（3%）例。结论 SVM能有效地对SPN良恶性进行较精确的预测,对医生正确诊断有很好的帮助。     

Bioavailability of Hydrophobic Organic Contaminants in Sediment with Different Particle-Size Distributions

Few studies have been conducted examining the distribution of different-sized particles in sediment and its potential impact on bioavailability of sediment-associated contaminants. In the current study, three sediments composed of different particle sizes, i.e., fine (0–180 μm), combined (0–500 μm), and coarse (180–500 μm), were used to evaluate the bioaccumulation potential and toxicokinetic rates of four hydrophobic organic contaminants (HOCs) including two polychlorinated biphenyls (PCB-101 and PCB-118), a metabolite of an organochlorine insecticide (p,p′-DDE), and a polybrominated diphenyl ether (BDE-47) to the benthic oligochaete Lumbriculus variegatus. Two chemical approaches, Tenax extraction and matrix-solid phase microextraction (SPME), were also used to measure bioavailability of the sediment-associated HOCs. The uptake and elimination rates of HOCs by L. variegatus from coarse sediment were greater than those from fine sediment, although the biota–sediment accumulation factors (BSAFs) were not significantly different among sediments with different particle sizes. The freely dissolved HOC concentrations measured by matrix-SPME were greater in coarse sediment, however, no difference was found in uptake and desorption rates for the matrix-SPME and Tenax extraction measurements. Although BSAFs in L. variegatus were the same among sediments, kinetic rates of HOCs for organisms and freely dissolved HOC concentrations were lower in fine sediment, suggesting that sediment ingestion may also play a role in organism uptake, especially for HOCs in fine sediment.     

TM种植体骨界面应力分布的有限元分析

背景：种植体形态是决定种植体骨界面应力分布的重要因素之一。探讨顺应人体正常颌骨解削形态的TM种植体骨界面的应力分布特征对临床医生选择和设计种植体有指导意义。目的：观察集中荷载作用下TM种植体及其周围骨组织应力分布的特征。方法：通过逆向工程技术,将二维下颌骨CT图片转化为三维实体模型,并建立3种包含不同锥度的TM种植体真实下颌骨B/2类骨质的有限元模型,利用有限元技术研究两种加载方式下TM种植体骨界面应力分布特征。结果与结论：垂直加载时,对于锥度较大的TM种植体周边密质骨承受较小的应力;斜向加载时,对于锥度较大的TM种植体周边密质骨和松质骨承受较大的应力;种植体颈部,密质骨上缘与种植体接触处和种植体底部松质骨出现明显应力集中现象,斜向荷载下种植体骨界面的应力分布显著高于垂直荷载下的应力分布。从1/2长度开始变化的TM种植体骨界面在垂直荷载下表现出较好的应力分布特征。     

结核分枝杆菌环介导恒温扩增（LAMP）快速检测方法的评价

目的 对国内建立的结核分枝杆菌DNA环介导恒温扩增（loop-mediated isothermal amplification, LAMP）快速检测方法进行了介绍和评价。 方法 实验菌株来源于北京结核病胸部肿瘤研究所。以结核分枝杆菌作为研究对象,设计了4 条LAMP 引物特异地识别结核分枝杆菌中 gyr B 基因的6个特殊区域。所有的菌株样本提取DNA作为模板,加入LAMP反应管后,65 ℃恒温反应60 min即可。其结果可以通过肉眼观察到的颜色变化来判断。 结果 实验共验证了79株临床和标准菌株。对于菌株的培养物,LAMP实验的灵敏度为100%,特异度为92%。 结论 结核分枝杆菌LAMP快速检测方法是一种快速、可靠的结核分枝杆菌诊断方法。