Study on Pollen Viability, Longevity and Pistil Receptivity of Self-Compatible Chrysanthemum with Small Inflorescences

Hongbo Zhao,Fadi Chen,Yanfang Wang,Weimin Fang,Sumei Chen,Weiming Guo 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Effects of RGD peptide grafting to titanium dental implantson the adhesion of human gingival fibroblasts and epithelial cells

BaoHong Zhao,WeiMing Tian,HaiLan Feng,이인섭,FuZhai Cui 한국물리학회 2005 Current Applied Physics Vol.5 No.5

The aim of this study is to test the adhesion of human gingival broblasts (HGFs) and epithelial cells (HGEs) to titanium surfaceby RGD grafting for dental implant, and to obtain an eective perimucosal seal of soft tissue to the implant. RGD peptides werecovalently attached to the titanium surface by CDI activation method to improve the adhesion of gingival cells to the titanium den-tal implants. HGFs and HGEs were inoculated on commercially pure (CP) titanium and RGD-grafted titanium. The number ofattached and proliferated cells was quantied by morphometric analysis using immunouorescence. The results showed that the bio-active peptide RGD was grafted on CP titanium by CDI activation method. The RGD grafting exhibited that the number ofattached and proliferated broblasts and epithelial cells were higher than that on CP titanium. The RGD-grafting is advantageous. to gingival cells adherence to the surface of titanium implant.

Plastic Deformation Mechanism of Ductile Fe50Ni30P13C7 Metallic Glass

Kangkang Geng,Weiming Yang,Jinyong Mo,Haishun Liu,Feng Wei,Zhanguo Ma,Yucheng Zhao,Akihisa Inoue 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

Shear band (SB) multiplication is considered as an essential characteristic of the plastic deformation in metallic glasses(MGs). In this work, the evolutionary characteristics of SBs and serrated behavior in ductile Fe50Ni30P13C7MGs werestudied by the finite element method simulation. The study demonstrated that the stress field would redistribute and becomeinhomogeneous during SB sliding, where the stress perpendicular to the original SB gradually accumulates until reachingthe magnitude of yielding strength and triggering new SBs. The results of simulation are in good agreement with the SBsintersection morphologies observed in SEM images and the serration flows on the stress–strain curves. Furthermore, severalfactors affecting stress field distribution in MGs, such as contact friction, aspect ratio, and boundary confinement, werealso analyzed and discussed. The overall results indicate that the ductility of Fe-based MGs could be achieved without anyinhomogeneous structure, and scientifically explicate the dependence of SB multiplication on both material properties andloading condition, which can provide us with a deeper understanding on plastic deformation mechanism of MGs.

Novel Strategy for Reducing Residual Stress in Titanium Alloy Parts Obtained via Additive Manufacturing

Xinfa Sun,Yucheng Zhao,Weiming Yang,Wenyu Li,Dengfeng Yang,Haishun Liu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

The additive manufacturing of titanium alloy parts has important scientific significance and practical value. Controllingthe distribution of residual stress caused by the high cooling rate and temperature gradient is the key to regulating the performanceof devices obtained from additive manufacturing. In this work, the effects of the interlayer scanning angle on theresidual stress in Ti–6Al–4V parts manufactured by selective laser melting were investigated by finite element simulations. We studied how changing the interlayer deflection angle alleviated residual stress under different energy inputs. The resultsshowed that the residual stress in the z-direction was reduced by the deflection angle of 67° and 90°, and the non-uniformdistribution of residual stress was reduced by a deflection angle of 67°. The combination of a chessboard pattern and interlayerdeflection angle greatly alleviated the generation of residual stress. This work has important guiding significance forthe additive manufacturing design of high-quality and high-performance titanium alloy devices.

MicroRNA-455-3p promotes TGF-β signaling and inhibits osteoarthritis development by directly targeting PAK2

Shu Hu,Xiaoyi Zhao,Guping Mao,Ziji Zhang,Xingzhao Wen,Chengyun Zhang,Weiming Liao,Zhiqi Zhang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

MicroRNAs (miRNAs, miR) play a key role in the pathogenesis of osteoarthritis (OA). Few studies have examined theregulatory role of P21-activated kinases (PAKs), a family of serine/threonine kinases, in OA. The aim of this study was todetermine whether miR-455-3p can regulate cartilage degeneration in OA by targeting PAK2. MiR-455-3p knockoutmice showed significant degeneration of the knee cartilage. MiR-455-3p expression increased and PAK2 expressiondecreased in the late stage of human adipose-derived stem cell (hADSC) chondrogenesis and in chondrocytesaffected by OA. Furthermore, in both miR-455-3p-overexpressing chondrocytes and PAK2-suppressing chondrocytes,cartilage-specific genes were upregulated, and hypertrophy-related genes were downregulated. A luciferase reporterassay confirmed that miR-455-3p regulates PAK2 expression by directly targeting the 3′-untranslated regions (3′UTRs)of PAK2 mRNA. IPA-3, a PAK inhibitor, inhibited cartilage degeneration due to OA. Moreover, suppressing PAK2promoted R-Smad activation in the TGF/Smad signaling pathway in chondrocytes. Altogether, our results suggest thatmiR-455-3p promotes TGF-β/Smad signaling in chondrocytes and inhibits cartilage degeneration by directlysuppressing PAK2. These results thus indicate that miR-455-3p and PAK2 are novel potential therapeutic agents andtargets, respectively, for the treatment of OA.

Study on activity of the signaling pathways regulating hepatocyte differentiation during rat liver regeneration

Cuifang Chang,Cunshuan Xu,Weiming Zhao,Jing Yang,Menghua Li,Yun Zhou 한국통합생물학회 2014 Animal cells and systems Vol.18 No.6

To understand the mechanism of hepatocyte differentiation during rat liver regeneration (LR) at the genetranscription level, Rat Genome 230 2.0 Array was used to determine the gene expression changes ofhepatocytes. Then the genes associated with cell differentiation and their signaling pathways were searched byNCBI, QIAGEN and KEGG webs, and their signaling activities were calculated by spectral function Ep(t)based on the expression profiles. The key genes associated with the signaling pathways and cell differentiationwere analyzed and verified by the same kind extraction method. The mechanism of hepatocyte differentiationduring rat LR was analyzed by Ingenuity Pathway Analysis 9.0 (IPA). The results showed that 42 signalingpathways regulated cell differentiation and the Ep(t) values of IL-9 signaling pathway and its JAK/STAT andPI3K/AKT branches, PEDF signaling pathway and its NF-κB and Ras/ERK branches were significantlyincreased in the progression phase (6–72 h after partial hepatectomy [PH]) of rat LR, and the Ep(t) values ofhepatocyte differentiation were also significantly increased. ERK/MAPK signaling pathway was significantlyincreased in the priming (0.5–6 h after PH) and progression phase, and hepatocyte differentiation were alsosignificantly increased. In conclusion, among the 42 signaling pathways that regulated cell differentiation, thesignaling activity of IL-9 signaling pathway and its JAK/STAT and PI3K/AKT branches, PEDF signalingactivity and its NF-κB and Ras/ERK branches, and ERK/MAPK signaling activity were significantly increasedand promoted hepatocyte differentiation in rat LR. Meanwhile, the expression of MYC involved in mentionedsignaling pathways and expression of AGT, BCL2, IL10, CCND1, PLAT, and NF1 related to celldifferentiation were increased significantly.

The Significantly Enhanced Mechanical and Tribological Performances of the Dual Plasma Nitrided and PVD Coated Ti6Al4V Alloy

Jiaqiang Yang,Kai Le,Hui Chen,Xu Zhao,Xiaodong Xie,Yong Luo,Shusheng Xu,Weiming Liu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.4

In this work, plasma pre-nitriding technique has been employed to enhance the bearing capacity for the TiN coating deposited on Ti6Al4V alloy by magnetron sputtering. The composition, morphology and mechanical property of the as-prepared samples were studied by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Vickers micro-hardness tester and nanoindentater. The tribological properties are investigated using a rotary tribometer under dry sliding and oil lubrication, and the mechanism was also discussed in details. The results show that the plasma nitriding treatment produced a nitrided layer with thickness of 85 μm on the surface of Ti6Al4V alloy, which significantly enhanced the mechanical properties. Therefore, the as-prepared TiN coated sample with plasma pre-nitriding treatment exhibit more excellent mechanical properties possessing the maximum hardness values (26 GPa) and exceptional load bearing capacity (74 N) compared to single TiN-coated Ti6Al4V. Moreover, the tribological properties of sample with plasma pre-nitriding treatment was also significantly improved, which was attributed to the synergistic effect of the superior bearing performance of nitriding layer and the high hardness of TiN coating. Additionally, wear mechanisms were discussed in terms of wear track morphology after sliding test.

Quantitative trait locus mapping and genomic selection of tobacco (Nicotiana tabacum L.) based on high-density genetic map

Tong Zhijun,Xiu Zhihui,Ming Yao,Fang Dunhuang,Chen Xuejun,Hu Yafei,Zhou Juhong,He Weiming,Jiao Fangchan,Zhang Chi,Zhao Shancen,Jin Han,Jian Jianbo,Xiao Bingguang 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.6

Tobacco ( Nicotiana tabacum L.) is an economic crop and a model organism for studies of plant biology and genetics. As an allotetraploid plant generated from interspecific hybridization, tobacco has a massive genome (4.5 Gb). Recently, a genetic map with 45,081 single nucleotide polymorphism (SNP) markers was constructed using whole-genome sequencing data for a tobacco population including 274 individuals. This provides a basis for quantitative trait locus (QTL) mapping and genomic selection, which have been widely applied to other crops but have not been feasible in tobacco. Based on this high-density genetic map, we identified QTLs associated with important agronomic traits, chemical compounds in dry leaves, and hazardous substances in processed cigarettes. The LOD values for major QTLs were highest for agronomic traits, followed by chemical compounds and hazardous substances. In addition to the identification of molecular markers, we evaluated genomic selection models and found that BayesB had the highest prediction accuracy for the recombinant inbred line population. Our results offer new insights into the genetic mechanism underlying important traits, such as agronomic traits and quality-related chemical compounds in tobacco, and will be able to support the application of molecular breeding to tobacco.

Local Joule heating targets catalyst surface for hydrocarbon combustion

Qian Xiong,Xingbao Zhu,Ri He,Xueyi Mei,Yexin Zhang,Zhicheng Zhong,Wei Zhao,Weiming Nie,Jian Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

Most industrial catalytic reactions are achieved by external heating and catalysts are entirely heated tooffer enough thermal energy to surface active sites. However, there is an inherent drawback that mostinput energy is dissipated into the bulk while minor is donated to the surface, leading to high energywaste. Here, we proposed a so-called local Joule heating method via passing an electric current throughpacked catalyst nanoparticles with a large contact resistance, which can generate sufficient heat to targetat the surface region. We selected hydrocarbon combustion, a common way to eliminate unburned pollutants,as a probe reaction and used the conductive antimony-doped tin oxide (ATO) as a model catalyst. Compared with traditional external heating, this method consumed one order lower energy input,reduced the macroscopically average temperature for same conversion by 100 C, improved the durabilitywith smaller activity loss within 100 h operation, and suppressed water poisoning effect by 60 %. Also, the combustion was sparked in seconds by pulsing electric current into the catalyst bed, allowing anapplication in prompt treatment of leaked hydrocarbons. The local Joule heating between contactednanoparticles, which could focus thermal energy on catalyst surface, is prospective to improve catalysisefficiency.