Effect of Iliac Vein Stent with Crown on Flow Field of Bifurcation

WenYing,Haiquan Feng,Xiaoqiang Li,Xiaotian Wang,Ping Cao,Yonggang Wang 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

Interference in blood flow at bifurcation after stent implantation is one of the important causes of thrombosis. Therefore, it is necessary to research the effects of stent structure and implantation position on hemodynamics. Computational fluid dynamics and experimental comparative research methods were used to analyze the influence of stent structure and position of stent on exit velocity, pressure difference between inlet and outlet, higher and lower wall shear stress areas and contralateral flow field. It is indicated in the research that the effect of iliac vein stent implantation on the flow velocity and pressure distribution at the outlet is not obvious, but stent implantation has an influence on the proportion of low wall shear stress and high wall shear stress area in the iliac vein. The low wall shear stress area is inversely proportional to the height of the stent. After stent is implanted, proportion of the high wall shear stress area will decrease, but the degree of decline is not obvious. As the height of stent is increased, the disturbing effect of stent on contralateral blood flow becomes more pronounced. In addition, it is confirmed by the experiments in vitro and in vivo that stent with crown would effectively reduce the interference to the contralateral flow field and the risk of thrombosis and restenosis. Finite element analysis provides effective theoretical support for studying the influence of iliac vein stent implantation on blood flow field.

Construction of rough and porous surface of hydrophobic PTFE powderembedded PVDF hollow fiber composite membrane for accelerated water mass transfer of membrane distillation

Wenying Shi,Tengfei Li,Mengjie Fan,Hongbin Li,Haixia Zhang,Xiaohong Qin 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

The construction of rough and porous hydrophobic membrane surface is expected to overcome the obstaclesincluding low permeate water flux and membrane pore wetting which greatly restrict the developmentof membrane distillation (MD) technology. In this study, a rough and porouspolytetrafluoroethylene (PTFE) powder-embedded polyvinylidene fluoride (PVDF) hydrophobic coatinglayer was compounded on the outer surface of PVDF hollow fiber support membrane by the dilute solutioncoating-phase inversion method. PVDF hollow fiber support membrane was fabricated by the dry-jetwet-spinning technique. PTFE powder was directly incorporated in PVDF dilute coating solution andembedded in the porous PVDF coating layer after the nonsolvent induced phase separation (NIPS). Thevariations of membrane morphology, surface chemical compositions, hydrophobicity and wetting resistancewere investigated by scanning electron microscope (SEM), Attenuated total reflection-Fouriertransform infrared spectroscopy (ATR-FTIR), dynamic water contact angle (WCA) and liquid entry pressure(LEP) analysis. Membrane separation performance including desalination and ionic dyes removalproperties was evaluated by VMD experiment. Compared with PVDF hollow fiber support membrane,both the surface hydrophobicity and the water permeability of the PTFE powder-embedded PVDF hollowfiber composite membrane (HFC) had obvious improvement. The surface WCA and permeate water fluxincreased from 92.6 and 11.3 kg/m2.h for PVDF support membrane to 133.6 and 26.8 kg/m2.h for thePTFE powder-embedded HFC membrane meanwhile NaCl rejection can be maintained above 99.9%(3.5 wt% NaCl aqueous solution at 50 C and permeate pressure at 31.3 kPa). The separation performanceof HFC membrane can remain stable without obvious pore wetting during the continuous MD operationfor 36 h. Different from the desalination, porous hollow fiber membrane would adsorb two differentcharged dyes, Congo red (CR) and methylene blue (MB) to a certain extent, resulting in the decrease ofmembrane flux and the change of permeate water quality. Finally, the MD separation mechanism of inorganicsalt, anionic dye and cationic dye by PTFE powder-embedded HFC membrane was proposed.

Continuous biodiesel production from acidic oil using a combination of the acid-, alkali-catalyzed membrane and GO/PVDF separation membrane

Wenying Shi,Tengfei Li,Hongbin Li,Qiyun Du,Haixia Zhang,Xiaohong Qin 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

An integrated process of esterification with phosphotungstic acid/poly (ether sulfone) (PWA/PES) membrane,transesterification with alkalized polysulfone (APSF) membrane and Graphene Oxide/poly (vinylidenefluoride) (GO/PVDF) separation membrane was carried out to produce biodiesel from acidic oil. Atthe first step, the PWA/PES membrane was introduced to catalyze the esterification reaction. The morphology,maximum pore size, porosity and catalytic esterification performance of PWA/PES membranewere investigated. After the esterification, products and reactants without reaction were put into theGO/PVDF separation membrane to soybean oil and other substances. The permeation mixture flux andsoybean oil rejection of the GO/PVDF separation membrane is 597.89 L/m2h and 98.02%, respectively. At the second step, the APSF membrane was added to catalyze the transesterification reaction in whichthe soybean oil reacted with methanol. The results showed that the esterification conversion was 98.6%and transesterification conversion was 91.2%. The main parameters of the biodiesel product obtainedmeet the Chinese Standard (GB/T 20828) and European Standard (EN 14214).

The Anti-compaction Behavior of Aramid Fiber Based Polyvinylidene Fluoride Composite Separation Membranes

Hongbin Li,Wenying Shi,Shuo Mei,Jinchao Li,Qiyun Du,Longwei Qin,Haixia Zhang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

Poly(p-phenylene terephthalamide) (PPTA), as the raw polymer material of Aramid fiber-1414, has high modulus and high strength which is commonly used in the reinforced composites. However, the general blending often accompany the microphase incompatibility in polymer matrix. In this study, PPTA molecules were incorporated into poly(vinylidene fluoride) (PVDF) membrane matrix through in situ polycondensation of p-phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution and PPTA/PVDF molecular composite membranes were prepared via the subsequent nonsolvent induced phase separation (NIPS) process. The anti-compaction properties of resulted PPTA/PVDF molecular composite membranes were systematically investigated including the variations of bursting pressure and membrane thickness, porosity, pure water flux under different pressures. The results suggested that membrane comprehensive anticompaction properties were improved with the increasing of PPTA content in PVDF membrane matrix. Combining the variation trends of membrane anti-compaction properties with morphologies, the compaction-deformation evolution processes of two membrane pore types (sponge-like and finger-like pores) were proposed at the end.

Rapid and Sensitive Detection of Hepatitis C Virus in Clinical Blood Samples Using Reverse Transcriptase Polymerase Spiral Reaction

Wenying Sun,Ying Du,Xingku Li,Bo Du 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.3

This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5’UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

Preparation of cMWCNTs-incorporated Hollow Fiber Membrane with Improved Water Flux and Dye Adsorption Properties

Wenying Shi,Hongbin Li,Qiyun Du,Shuo Wang,Haixia Zhang,Xiaohong Qin 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

Carboxylated multi-walled carbon nanotubes (cMWCNTs) were incorporated in membrane matrix during the drywet spinning process to improve membrane performance. Membrane surface composition and morphology were examined by means of FTIR and SEM. The effects of cMWCNTs content on membrane surface hydrophilicity, separation performanceand dye adsorption properties were well investigated and characterized through WCA examination, the cross-flow filtration measurement and the adsorption experiment. The surface hydrophilicity, the water permeability, solute rejection and dye adsorption properties of the cMWNTs-incorporated hollow fiber membranes have been all improved. When cMWNTs content was 0.3 wt%, the cMWNTs-incorporated hollow fiber membrane obtained the obvious enhanced pure water flux (137.2 L·m-2·h-1, at 0.1 MPa) which was 1.5 times as high as that of the original PSF hollow fiber membrane. The preparedcMWCNTs-incorporated membranes are expected to be used in the treatment of textile dyeing wastewater or employed as the supports of the composite membranes.

Spatial processes of regional innovation in Guangdong Province, China: empirical evidence using a spatial panel data model

Ting Li,Wenying Fu 기술경영경제학회 2015 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.23 No.3

Spatial processes are highly relevant phenomena in innovation studies. Regional innovation isboth influenced by heterogeneous regional attributes and the neighbouring innovation factors. Spatial econometrics are developed to explicitly cope with the issues of spatial dependence. This paper aims to reveal the spatial processes of regional innovation at the city scale byincluding the spatial terms in panel data specification. The research region, GuangdongProvince, has developed into one of innovation hubs in China. Panel data set in 21municipalities in Guangdong Province over the period of 2001– 2013 has been established. The spatial panel data model shows that regional innovation in Guangdong is driven byR&D expenditure input. Besides, inflow of external knowledge boosts the innovation outputthrough foreign investment stock and imported goods, and it strengthens its role asinnovation impetus for the neighbouring cities with the spatial spillover effect. Meanwhile,the depth and width of knowledge accumulated by specialisation economy anddiversification economy contribute to innovation both for the city itself and theneighbouring cities. Overall, the paper has succeeded in revealing the effect of spatialdependence of innovation output, as well as the ‘spilling over’ of the innovation factors ondistance-based spatial relations.

Finite-time Set Stabilization of Impulsive Probabilistic Boolean Control Networks via Time-variant Feedback Control

Qilong Sun,Wenying Hou,Haitao Li,Jing Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

This paper investigates the finite-time set stabilization of impulsive probabilistic Boolean control networks (IPBCNs) by designing time-variant state feedback control. Based on the semi-tensor product method, the algebraic form is established for the given IPBCNs. Then, a constructive method is proposed to design time-variant state feedback controller for the set stabilization of IPBCNs. In order to reduce the control execution time, a specific method is put forward to construct the event-triggered state feedback control (ETSFC). Furthermore, the obtained results are applied to both state synchronization and output synchronization of master-slave IPBCNs.

Preparation and characterization of chitosan-poly (vinyl alcohol)/polyvinylidene fluoride hollow fiber composite membranes for pervaporation dehydration of isopropanol

Jing Wang,Wenying Zhang,Weixing Li,Weihong Xing 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.7

A new hollow fiber composite membrane of chitosan-poly (vinyl alcohol)/polyvinylidene fluoride (CSPVA/ PVDF) was prepared by casting the solution of CS and PVA on PVDF hollow fiber support for pervaporation dehydration of isopropanol. The composite membranes were crosslinked with glutaraldehyde (GA) and sulfuric acid. The microstructure and physicochemical properties of the membranes were characterized by scanning electron microscope (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetry (TG) and contact angle measurements. Results from SEM images showed that dense separation layers were successfully coated onto the supports, and the ATR-FTIR results showed that GA had crosslinked the composite membranes. Results of TG and contact angle showed the thermostability of membranes increased and the hydrophilicity decreased after blending CS and PVA. The swelling degree of composite membranes increased with increasing CS content and water content. Effects of the content of CS and GA in solution on membrane separation performance were investigated. The pervaporation experiments for dehydration of isopropanol showed that the membrane with 60 wt% CS and 0.1 wt% GA had a good separation performance. The permeate flux was 306 g/(m2·h) and the separation factor was 2140 for the feed solution containing 90% isopropanol at 60 oC. When the water content increased from 3 wt% to 15 wt%, the permeate flux increased from 207 g/(m2·h) to 346 g/(m2·h) while the separation factor decreased from 2406 to 1876. The separation factor and permeation flux increased with feed temperature.

Fine Mapping of qHD8-1, a QTL Controlling the Heading Date, to a 26-kb DNA Fragment in Rice (Oryza sativa L.)

Chengguo Pei,Xu Liu,Wenying Wang,Hanfeng Ding,Mingsong Jiang,Guangxian Li,ChangXiang Zhu,FuJiang Wen,Fangyin Yao 한국식물학회 2011 Journal of Plant Biology Vol.54 No.3

Heading date is one of the importance agronomic traits. A library consisting of 1,123 single segment substitution lines (SSSLs) in the same genetic background of an elite rice variety Huajingxian 74 (HJX74) was evaluated for heading date (HD). From this library, the SSSL W06-26-35-1-5-2 with the substituted interval of PSM152–PSM154–PSM155–RM25–RM547–RM72–RM404 was found having a gene, which performed stable and late heading in the different environments of Shandong and Hainan provinces. To map the gene governing heading date, the SSSL W06-26-35-1-5-2 was crossed with the recipient HJX74 to develop an F_2 segregating population. The distribution of late and early heading plants in this population fitted a segregation ratio of 3:1, indicating the late heading was controlled by a dominant gene. The gene locus for heading date was tentatively designated as qHD8-1. Using a random sample of 460 individuals from the F_2population, the qHD8-1 was narrowed down to a region flanking by two SSR markers PSM155 and RM547. For fine mapping of qHD8-1, a large F_2:3 segregating population of 3,000 individuals were developed from F_2 plants heterozygous in the PSM155–RM547 region. Recombinants analysis further mapped qHD8-1 to an interval of region 26 kb with markers RM22492 and P23 bounded on the left and right sides, respectively. Sequence analysis of this 26-kb fragment revealed that it contains five putative open reading frames,which were regarded as candidates of qHD8-1. These results will be useful in cloning of the qHD8-1 gene