Numerical Simulation of the Nozzle with Self-Oscillating Flow Using the Vof Model

普通喷嘴喷出的水柱是直线型的,在普通喷嘴中加入倒u型和三角形结构,就能够使得喷嘴喷出来的水柱呈现振荡形式。利用多相流VOf(VOluME Of fluId)模型模拟内建振荡结构的喷嘴的喷射流动过程,Cfd仿真结果显示,喷嘴喷射的水柱呈现上下摆动的状态,和真实情况相吻合。The jet water shape of the nozzle will become a self-oscillating shape,if the triangle and U shape models are made into the normal nozzle.Using the Vof model,the jet shape of the nozzle will be simulated through a commercial CFD software FLUENT.The Vof model(Volume of Fluid) is a surface-tracking technique applied to a fixed Eulerian mesh.It is designed for two or more immiscible fluids where the position of the interface between the fluids is of interest.The CFD simulation results shows that the jet shape of the nozzle is oscillate in a fixed period

Promotion of proliferation of luminal B breast cancer cells by mesenchymal stem cells and its underlying molecular mechanisms

目的分析人脐带间充质干细胞(hUC-MSCs)对Luminal B型乳腺癌细胞生长增殖的影响,并初步探讨其可能的分子机理。方法绿色荧光蛋白(GFP)和荧光素酶共表达慢病毒感染人Luminal B型乳腺癌细胞BT474,并经嘌呤霉素筛选两周后,于荧光显微镜下观察GFP的表达情况,IVIS Kinetic成像系统拍照以观察和记录慢病毒感染后BT474细胞荧光素酶的表达情况;荧光显微镜下直接观察,结合MTS实验分析hUC-MSCs共培养或其浓缩上清处理对GFP和荧光素酶共表达BT474细胞生长增殖的影响;Western blot法检测hUC-MSCs浓缩上清处理对BT474细胞Akt和MAPK信号通路激活情况以及下游细胞周期调控蛋白Cyclin D1表达的影响;常规RT-PCR法检测hUC-MSCs中NRG-1、NRG-2、IGF-Ⅰ、IGF-Ⅱ和EGF等配体的表达。荧光素酶表达强度与细胞数量的相关性经由Excel软件行统计学分析,MTS实验数据则经由SPSS13.0统计软件行统计学分析。结果荧光显微镜和IVIS Kinetic成像系统的观察结果分别证实,GFP和荧光素酶经慢病毒载体系统的介导可在BT474细胞中成功地共表达,且荧光素酶的表达强度与细胞数量呈直线相关。MSCs共培养或其浓缩上清处理均可显著促进Luminal B型乳腺癌细胞BT474的生长增殖,其细胞存活比例分别为各自对照组的148.06%(P<0.005)和147.99%(P<0.001);MSCs浓缩上清处理同时激活BT474细胞内Akt和MAPK信号通路,并上调细胞周期调控蛋白Cyclin D1表达。此外,RT-PCR结果显示,hUC-MSCs中NRG-1和EGF的mRNAs水平呈高表达,而NRG-2、IGF-Ⅰ和IGF-Ⅱ等配体的mRNAs表达也可见。结论 MSCs可通过表达并分泌NRG-1等配体,从而激活Luminal B型乳腺癌细胞BT474的下游Akt和MAPK信号转导通路以上调细胞周期调控蛋白Cyclin D1的表达,进而促进其生长增殖。Objective To investigate the effect of human umbilical cord mesenchymal stem cells(hUC-MSCs) on proliferation of luminal B breast cancer cells and its underlying molecular mechanisms. Methods Human luminal B breast cancer cells BT474 were infected with GFP and luciferase co-expressing lentiviruses and then subjected for selection with Puromycin for 2 weeks. The expression of GFP and luciferase was detected by fluorescent microscopy and IVIS Kinetic image system, respectively. The effect of coculture or treatment with conditioned medium of hUCMSCs on proliferation of BT474 was analyzed with MTS assay. Western blot was carried out to detect the effect of treatment with conditioned medium of hUC-MSCs on the activation of both Akt and MAPK signalings in BT474, as well as the expression of downstream cell cycle regulator Cyclin D1. Regular RT-PCR was applied to analyze the mRNAs expression of ligands such as NRG-1, NRG-2, IGF-Ⅰ, IGF-Ⅱ, and EGF in hUC-MSCs. The correlation between relative luciferase activity and cell number was analyzed with Excel software, while MTS assay data was statistically analyzed with SPSS 13.0 software. Results The co-expression of GFP and luciferase in BT474 via lentiviral expression system was visualized by fluorescent microscopy and IVIS Kinetic image system. The linear correlation between relative luciferase activity and cell number was determined by curve fitting analysis. Coculture or treatment with conditioned medium of hUC-MSC significantly promoted the proliferation of BT474, with survival rates being 148.06 %(P < 0.005)and 147.99 %(P < 0.001)of control, respectively. In addition, treatment with conditioned medium of hUC-MSC was shown to induce activation of both Akt and MAPK signalings, which further upregulated the expression of Cyclin D1. Moreover, high mRNAs expression levels of both NRG-1 and EGF, as well as moderate mRNAs expression levels NRG-2, IGF-Ⅰ, and IGF-Ⅱ were showed by RT-PCR. Conclusion Our results here demonstrated that MSCs may promote the proliferation of luminal B breast cancer cells through paracrine of ligands such as NRG-1, which in turn results in the activation of both Akt and MAPK signalings and upregulation of the expression of Cyclin D1.国家自然科学基金面上项目(81272922);; 福建省自然科学基金面上项目(2016J01577);; 福州总医院院内课题国际合作研究专项(2015G01

添加表面活性剂两步沉淀法制备甲醇催化剂

采用添加表面活性剂两步沉淀法制备了具有高表面铜相对浓度的超细甲醇合成催化剂：以组成为H2／CO／CO2／N2=66／27／3／4（体积比）的原料气对催化剂进行了活性评价。结果表明，该催化剂比传统并流沉淀法制备的铜基催化剂活性提高47．9％．比两步沉淀法和添加表面活性剂并流沉淀法制备的铜基催化剂活性分别提高9．3％和16．8％。利用SEM、XRD及XPS方法对催化剂的结构、形貌和表面金属组成进行了表征