Modeling the Transmission of Middle East Respirator Syndrome Corona Virus in the Republic of Korea

The 2015 epidemic of Middle East respiratory syndrome (MERS) in the Republic of Korea has been the largest outbreak outside Middle East. This epidemic had caused 185 laboratory-confirmed cases and 36 deaths in the Republic of Korea until September 2, 2015, which attracted public’s attention. Based on the detailed data of patients released by World Health Organization (WHO) and actual propagation of the epidemic, we construct two dynamical models to simulate the propagation processes from May 20 to June 8 and from June 9 to July 10, 2015, respectively and find that the basic reproduction number R₀ reaches up to 4.422. The numerical analysis shows that the reasons of the outbreak spread quickly are lack of self-protection sense and targeted control measures. Through partial correction analysis, the parameters β₁ and γ have strong correlations with R₀, i.e., the infectivity and proportion of the asymptomatic infected cases have much influence on the spread of disease. By sensitivity analysis, strengthening self-protection ability of susceptible and quickly isolating or monitoring close contacts are effective measures to control the disease.     

Theoretical insights into the effects of molar ratios on stabilities,mechanical properties,and detonation performance of CL-20/HMX cocrystal explosives by molecular dynamics simulation

To research and estimate the effects of molar ratios on structures, stabilities, mechanical properties, and detonation properties of CL-20/HMX cocrystal explosive, the CL-20/HMX cocrystal explosive models with different molar ratios were established in Materials Studio (MS). The crystal parameters, structures, stabilities, mechanical properties, and some detonation parameters of different cocrystal explosives were obtained and compared. The molecular dynamics (MD) simulation results illustrate that the molar ratios of CL-20/HMX have a direct influence on the comprehensive performance of cocrystal explosive. The hardness and rigidity of the 1:1 cocrystal explosive was the poorest, while the plastic property and ductibility were the best, thus implying that the explosive has the best mechanical properties. Besides, it has the highest binding energy, so the stability and compatibility is the best. The cocrystal explosive has better detonation performance than HMX. In a word, the 1:1 cocrystal explosive is worth more attention and further research. This paper could offer some theoretical instructions and technological support, which could help in the design of the CL-20 cocrystal explosive.     

Characterization of the BPI-like gene from a subtracted cDNA library of large yellow croaker (Pseudosciaena crocea) and induced expression by formalin-inactivated Vibrio alginolyticus and Nocardia seriolae vaccine challenges

One expressed sequence tag (EST 64LF004 clone), which is from the subtracted cDNA library of the head kidney of large yellow croaker (Pseudosciaena crocea) stimulated with peptidoglycan (PG) by suppression subtractive hybridization (SSH) method, was cloned using RACE-PCR. The full length cDNA, which possesses typical structural features of a signal peptide, a conserved LPS binding domain and two bactericidal permeability-increasing (BPI) motifs as in higher vertebrates, was identified as a novel homologue, namely of the large yellow croaker BPI-like molecule (Pc-BPI-L). Phylogenetic analysis showed this Pc-BPI-L of large yellow croaker as the most ancestral branch in bony fish clade. The recombinant Pc-BPI-L protein expressed in the Tn-5B1-4 insect cells was successfully produced and confirmed to have the predicted size of 52 kDa by Western blot analysis. At the message level, Pc-BPI-L mRNA was ubiquitously expressed in all tissues examined. Following formalin-inactivated Vibrio alginolyticus and Nocardia seriolae treatment, Pc-BPI-L message was differentially up-regulated in primary immune organs. These results indicate that Pc-BPI-L might be involved in the immune response to bacterial infection.     

食品中桔霉素控制方法的研究进展

桔霉素(Citrinin,CIT)是由青霉、曲霉和红曲霉属产生的一种具有肾毒性的真菌毒素。许多食品和饲料中均含有桔霉素,污染范围十分庞大。桔霉素可与其他真菌毒素发生协同作用,如展青霉素(Patulin,PAT)、赭曲霉毒素(Ochratoxin,OTA)等,从而增强其毒性作用,对人及动物健康造成更大的危害。现阶段常用的控制手段主要有物理、化学和生物方法,均取得了一定的成就。本文简单介绍了桔霉素的毒性及污染状况,对桔霉素控制方法的研究进展进行了综述。     

肿瘤坏死因子相关的凋亡诱导配体(TRAIL)cDNA的克隆、表达和活性测定

肿瘤坏死因子相关的凋亡诱导配体 (TRAIL)能选择性诱导肿瘤细胞凋亡 .为利用基因工程技术获得重组TRAIL蛋白可溶性片段 (sTRAIL) ,设计 1对引物 .利用PCR技术特异性扩增出sTRAIL的cDNA ,克隆于质粒pGEM 3Zf( )的EcoRⅠ和PstⅠ位点 .经测序证明序列正确后克隆于表达质粒pBV2 2 0的EcoRⅠ和PstⅠ位点 ,转化大肠杆菌DH5α .转化菌株经温度诱导 ,SDS PAGE检测和Western印迹鉴定 ,获得重组sTRAIL的高水平非融合表达菌株 .表达量占菌体总蛋白的 2 0 % .对其表达产物进行了初步纯化 ,SDS PAGE结果显示纯度可达 90 %以上 .用L92 9细胞测定其生物学活性表明 ,重组蛋白在体外能明显诱导肿瘤细胞凋亡     

正常大鼠胃黏膜中肌球蛋白轻链激酶定性和定位观察

目的观察正常大鼠胃组织中肌球蛋白轻链激酶的表达及分布特点。方法取11只SD正常雄性大鼠,在饥饿状态下,处死后取胃组织。通过免疫组化染色,观察正常大鼠胃组织中MLCK的表达及分布。结果MLCK在黏膜肌层、肌层和黏膜下层血管壁平滑肌均有大量表达;在胃底腺中,MLCK主要表达于壁细胞和主细胞胞浆内。结论MLCK不仅存在于平滑肌细胞内,还分布于胃底腺壁细胞和主细胞内,可能参与胃底腺腺细胞的分泌活动。     

Structural basis of a flavivirus recognized by its neutralizing antibody: solution structure of the domain III of the Japanese encephalitis virus envelope protein

The flavivirus envelope protein is the dominant antigen in eliciting neutralizing antibodies and plays an important role in inducing immunologic responses in the infected host. We have determined the solution structure of the major antigenic domain (domain III) of the Japanese encephalitis virus (JEV) envelope protein. The JEV domain III forms a beta-barrel type structure composed of six antiparallel beta-strands resembling the immunoglobulin constant domain. We have also identified epitopes of the JEV domain III to its neutralizing antibody by chemical shift perturbation measurements. Site-directed mutagenesis experiments are performed to confirm the NMR results. Our study provides a structural basis for understanding the mechanism of immunologic protection and for rational design of vaccines effective against flaviviruses.     

The first intron of rice EPSP synthase enhances expression of foreign gene

The first intron (EPI) of rice 5-enolpyruvylshikimate 3-phosphate synthase gene was isolated by PCR from one clone with genomic EPSP synthase gene. Sequence analysis showed that the first intron is 704 bp in length with 36.2% G+C content. To investigate its effect on expression of foreign gene, we inserted the first intron between CaMV35S promoter and β-glucuronidase (GUS) gene. The transient expression results showed that GUS could be expressed effectively with EPI. The GUS activity in transgenic tobacco shows that the EPI can greatly enhance the expression level of β-glucuronidase (P < 0.01) compared with transgenic tobacco without the first intron, and 3-to 6-fold increase in GUS activity in some transgenic tobaccos. Northern blot indicated the first intron was spliced from GUS pre-mRNA, and the steady-state mRNA levels of GUS with EPI in transgenic tobaccos were higher than that in transgenic tobacco without EPI, which suggested that the first intron of EPSP was a non-translated intron.     

阴道微生态在早产中的研究进展

阴道微生态是由阴道的局部解剖结构、周期性的内分泌变化、阴道局部免疫系统和阴道内微生物菌群共同组成的阴道环境和生态系统。多项研究证实阴道微生态失调通过局部炎症因子释放、黏膜免疫应答的改变和局部代谢变化,可引起早产的发生。阴道内小分子物质如糖类、短链脂肪酸和胺类通过代谢路径和代谢产物在阴道微生态失调与早产的发病机制起作用。近年来,阴道微生态的理念得到重视,治疗方法由传统的抗生素治疗转向了综合治疗,目的是恢复正常阴道菌群和阴道上皮黏膜免疫系统。但阴道微生态与宿主之间存在复杂的相互作用,因此仍需要进一步的研究。