水平管道水合物浆液流动特性的数值模拟

基于欧拉双流体模型,结合颗粒动力学理论,研究不同水合物颗粒体积分数、不同流速下非均匀颗粒水合物浆液流动过程中水合物颗粒聚集行为、流动压降及浆液速度分布。结果表明:浆液流动压降主要受流速影响,速度越大压降越大。颗粒体积分数在20%—35%,压降变化很小,当颗粒体积分数达到55%时,压降明显变大。水合物颗粒聚集程度随流速增大而降低,低水合物颗粒体积分数下,颗粒聚集呈悬浮状。随颗粒体积分数增大,水合物颗粒呈堆积状聚集,易造成管道堵塞;水合物浆速度梯度随颗粒体积分数增大而增大。随流速增大,速度由非对称变成对称分布,出现较大的速度梯度。保障水合物浆稳定安全流动存在一个临界颗粒体积分数和经济流速。数值模拟为水合物浆液管道输送技术的研究提供理论参考。

河南省部分地区腹泻仔猪流行性腹泻病毒和δ冠状病毒检测与分析

为了解河南省部分地区猪流行腹泻病毒(PEDV)和猪δ冠状病毒(PDCoV)的流行状况,根据GenBank中登录的PEDV M基因及PDCoV M基因序列,分别设计扩增引物,采用单一RT-PCR方法对2017年3月至2018年1月采集的154份样品进行检测。结果显示,PEDV的阳性率为51.92%,PDCoV的阳性率为35.06%,混合感染率为24.03%。说明PEDV和PDCoV是普遍存在于腹泻猪群中的病毒,是引起河南仔猪腹泻的重要原因。

新发猪Delta冠状病毒和猪流行性腹泻病毒SYBR GreenⅠ双重荧光RT-PCR检测方法的建立及应用

猪Delta冠状病毒（porcine delta coronavirus，PDCoV）是一种新发现的仔猪腹泻类冠状病毒，感染仔猪主要表现出水样腹泻、呕吐和脱水等临床症状，和猪流行性腹泻（porcine epidemic diarrhea，PED）临床症状极其类似，且I临床上混合感染病例较多，单靠临床症状和剖检变化很难辨别这2种疾病，因此建立同时检测且能区分PDCoV和PEDV的检测方法具有重要意义。参照GenBank登录的PDCoVM基因和PEDVORF3基因特异性序列设计引物，扩增相应的基因片段，克隆构建重组质粒pMD-18T—PDCovM与pMD-18T—PEDVORF8，测序验证后，分别以此重组质粒为标准品，建立了能同时检测PDCoV和PEDV的SYBRGreenI双重荧光RTPCR方法，并对其扩增体系和扩增条件等进行了优化，同时对所建立的双重荧光RT—PCR方法的特异性、灵敏性和重复性进行了检测。结果显示，该试验成功建立了能同时检测PDCov和PEDv的SYBRGreenI双重荧光RTPCR方法，最低能检测到PDCoV和PEDV分别是28．6拷贝/μL和99．6拷贝/μL的质粒浓度，显示出较好的敏感性；在同样扩增条件下该方法具有较好的重复性；特异性试验表明，该方法仅能检测出PEDV和PDCoV，而对猪传染性胃肠炎病毒（TGEV）、猪繁殖与呼吸综合征病毒（PRRSV）、猪圆环病毒2型（PCV2）和猪伪狂犬病毒（PRV）等均不产生特异性扩增曲线。将所建立的双重荧光RTPCR方法以及单重荧光定量RT—PCR方法分别对198份临床收集的仔猪腹泻样品进行PEDV和PD—CoV检测，结果显示，PDCoV阳性样品41份，阳性率为20．7％；PEDV阳性样品59份，阳性率为29．8％；同时感染这2种病毒的样品17份，阳性率为8．6％。与单重荧光定量RT—PCR方法对PEDV和PDCoV的检出率一样，符合率100．0％。本研究成功建立了PDCoV和PEDV的双重荧光RT—PCR方法，能同时准确地检测PDCoV和PEDV，这为PDCoV和PEDV的临床鉴别诊断和流行病学调查研究奠定基础。

Construction of recombinant adenovirus co-expression vector carrying the human transforming growth factor-β1 and vascular endothelial growth factor genes and its effect on anterior cruciate ligament fibroblasts

Background Remodeling of the anterior cruciate ligament （ACL） graft usually takes longer than expected. Gene therapy offers a radical different approach to remodeling of the graft. In this study, the internal ribosome entry site （IRES） sequence was used to construct a new recombinant adenovirus which permits co-expression of transforming growth factor-β1 （TGFβ1） and vascular endothelial growth factor 165 （VEGF165） genes （named Ad-VEGF165-IRES-TGFβ1）. We investigated the effects of the new adenovirus on the migration of and matrix synthesis by ACL fibroblasts. Methods Adenoviral vector containing TGFβ1 and VEGF165 genes was constructed. ACL fibroblasts were obtained from New Zealand white rabbits. After ACL fibroblasts were exposed to Ad-VEGF165-IRES-TGFβ1, the expression of VEGF165 and TGFβ1 proteins were assessed by enzyme-linked immunosorbent assay （ELISA） and Western blotting analysis. Bioassay of VEGF165 and TGFβ1 proteins were assessed by Western blotting analysis. Proliferation and migration of ACL fibroblasts were assessed by in vitro wound closure assay. Gene expression of collagen type Ⅰ, collagen type Ⅲ, and fibronectin mRNA among matrix markers were assessed by real-time PCR. Results The results showed the successful construction of a recombinant co-expression adenovirus vector containing TGFβ1 and VEGF165 genes. Co-expression of TGFβ1 and VEGF165 can induce relatively rapid and continuous proliferation of ACL fibroblasts and high gene expression of collagen type Ⅰ, collagen type Ⅲ, and fibronectin mRNA among matrix markers. Conclusion Co-expression of TGFβ1 and VEGF165 genes has more powerful and efficient effects on the migration of and matrix synthesis by ACL fibroblasts.