Response of Photosynthetic Characteristics to Different Salicylic Acid Concentrations in Relation to Waterlogging Resistance in Zanthoxylum armatum

Peiyun Wang,Chengyi Su,Jiaojiao Wu,Yuxin Xie,Jiangtao Fan,Jingyan Wang,Wenkai Hui,Hua Yang,Wei Gong 한국원예학회 2023 원예과학기술지 Vol.41 No.4

Zanthoxylum armatum (Rutaceae) is an important spice and a traditional medicinal plant in southwest China. Owing to its shallow root system, it is highly susceptible to waterlogging stress. To evaluate how an exogenous salicylic acid (SA) application reduces photosynthetic damage in Z. armatum under waterlogging stress conditions, the content of photosynthetic pigments and gas exchange and chlorophyll fluorescence parameters were studied under different SA concentrations (0, 1 and 2 mM) and different numbers of waterlogging days (1, 2 and 3 d) to identify the mechanisms underlying the seedlings’ waterlogging response. The results showed that waterlogging significantly affects the photosynthetic characteristics in leaves. An exogenous SA application increased the contents of photosynthetic pigments as well as the transpiration rate (Tr), net leaf photosynthetic rate (Pn), stomatal conductance (Gs), water use efficiency (WUE), actual quantum efficiency (ΦPSII), photosystem II (PSII) maximum quantum efficiency (Fv/Fm), PSII photochemical efficiency in light (Fv'/Fm'), and electron transport rate (ETR), whereas the treatment decreased the intercellular carbon dioxide concentration (Ci), non-photochemical quenching coefficient (NPQ) and minimum fluorescence (Fo). Therefore, the SA application helps improve the photosynthetic efficiency and reduce photodamage to Z. armatum in the event of waterlogging stress.

MicroRNA-34a inhibits cell invasion and epithelial-mesenchymal transition via targeting AXL/PI3K/AKT/Snail signaling in nasopharyngeal carcinoma

Chengyi Jiang,Zhongqiang Cheng,Tao Jiang,Yajia Xu,Bin Wang 한국유전학회 2020 Genes & Genomics Vol.42 No.8

Background MicroRNA-34a (miR-34a) has been reported to inhibit TGF-β (transforming growth factor-β)-induced epithelialmesenchymal transition (EMT) in nasopharyngeal carcinoma (NPC). However, the underlying mechanism remain unclear. Using the bioinformatics, we found that the AXL receptor tyrosine kinase (AXL) is a predicted target of miR-34a. Objective we aimed to reveal the relationship between miR-34a and AXL, and investigate the effect and mechanism of miR-34a in NPC progression. Methods The expression patterns of miR-34a and AXL in 30 paired NPC tissues and the adjacent tissues were examined by quantitative real time PCR (qRT-PCR). The target relationship between miR-34a and AXL was evaluated by the luciferase gene reporter assay. Cell migration and invasion were assessed by wound healing and transwell chamber assays, respectively. Results miR-34a level was dramatically decreased in the NPC tissues compared to the adjacent tissues, while AXL expression was increased. Overexpression of miR-34a significantly reduced the luciferase activity of the luciferase vector of AXL (pGL3-AXL-WT), whereas this effect was abrogated when binding sites between miR-34a and AXL were mutated. In addition, ectopic expression of miR-34a dramatically inhibited Sune-1 cell migration and invasion abilities, decreased the levels of N-cadherin and Vimentin and increased E-cadherin and γ-catenin expressions, as well as induced significant reductions in the expressions of p-AKT and Snail. However, these effects were attenuated when the cells were treated with recombinant human AXL protein. Conclusions Our results demonstrate that miR-34a/AXL can inhibit NPC cell migration, invasion and EMT through inhibition of AKT/Snail signaling.

Study on microstructure wear reduction performance and life prediction of unfolding wheel

Chengyi Pan,Jiahao Chang,Chuan Wang,Yanguang Gu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

The unfolding wheel for testing steel ball is apt to wear. Manufacturing microstructure at its surface is a method to reduce wear. Firstly, friction and wear experiments were conducted with load and microstructure area as variables. The friction coefficients and wear mass of the specimens were measured. The friction and wear performance of the microstructure surface is studied by analyzing the data trend of friction coefficient and wear mass. Then, the mechanism on wear resistance of microstructure surface is analyzed. The mathematical model of wear is deduced based on the Archard wear model. The finite element simulations of wear of microstructure surface and smooth surface were conducted through ANSYS software respectively. Finally, the equation relationship between the unfolding wheel life and the number of wear is established by fitting the data from the simulation results using MATLAB. The predicted result shows that the unfolding wheel life of the microstructure surface is about 26.5 % longer than that of the smooth surface.

Study on design and simulation of a novel isolator cylindrical roller bearing

Chengyi Pan,Chuan Wang,Yanling Zhao,Guanqun Cao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

The sliding friction of the cylindrical roller bearing makes the internal resistance of the bearing large. Thus, this paper proposes to replace the cage with rolling isolators being placed between the cylindrical rollers, making the rub of all the elements be rolling friction. Therefore, the driving torque of the bearing is greatly reduced. First, the structure and working principle of this kind of bearing are described, the geometric parameter relationship of the roller and the isolator is analyzed, the feasible range of the parameters of the isolator is deduced based on the NFL203V type cageless bearing is proposed. Then, the ADAMS software is used for motion simulation of this novel cylindrical roller bearing. The best design plan is obtained through a comparison of the different schemes. Finally, experiments of bearing temperature are conducted, which shows the working temperature of the isolator cylindrical roller bearing is lower than that of the traditional roller bearings.

Forest Height Extraction from PolInSAR Image Using a Hybrid Method

Nghia Pham Minh,Chengyi Wang,Bin Zou,Quang Thi Nguyen,Van Nhu Le 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.2

Discrete theory of rolling elements for a cageless ball bearing

Yanling Zhao,Qiyu Wang,Mingzhu Wang,Chengyi Pan,Yudong Bao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

For the case of magnetic levitation loss, the rotor of an active magnetic bearing is forced by gravity to drop onto stator laminations, and cageless touchdown bearings with high rigidity and load-bearing capacity ensure back-up support. However, the contact collision of rolling elements in a cageless bearing will lead to deterioration of bearing performance and instability of the rotor system. For this purpose, a method based on noncontact between adjacent rolling elements in cageless bearings is proposed in this paper. First, combined with space geometry, the contact process and the change in radius of rotation when a rolling element passes through a discrete groove are analysed, and a clearance between the adjacent rolling elements is generated by changing the rotation speed. Based on this, a design principle for setting a discrete groove on an outer ring raceway is proposed, and the equation for the circumferential discrete clearance for the rolling element based on bearing kinematics is given. Combined with the characteristics of discrete groove structures, a differential equation for the discrete dynamics of rolling elements with variable stiffness coefficients is proposed. We then determine the influence of the discrete groove structure on the discrete motion of the rolling element and bearing dynamic characteristics. Third, the dynamics simulation is combined with a vibration characteristics experiment and discrete motion experiment for a rolling element in a cageless bearing. Our research results show that a discrete groove design for the raceway can be used to realize stable discrete motion of the rolling element, and that such a discrete groove structure will not adversely affect the vibration characteristics of the bearing. The feasibility of the discrete design of cageless bearings with rolling element is verified, and theoretical guidance for the development and application of cageless bearings is provided.

Regulation of precursor solution concentration for In-Zn oxide thin film transistors

Zhongyuan He,Yanping Chen,Yaogang Li,Qinghong Zhang,Chengyi Hou,Hongzhi Wang 한국물리학회 2018 Current Applied Physics Vol.18 No.11

The tunable electronic performance of the solution-processed semiconductor metal oxide is of great significance for the printing electronics. In current work, transparent thin-film transistors (TFTs) with indium-zinc oxide (IZO) were fabricated as active layer by a simple eco-friendly aqueous route. The aqueous precursor solution is composed of water without any other organic additives and the IZO films are amorphous revealed by the X-ray diffraction (XRD). With systematic studies of atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS) and the semiconductor property characterizations, it was revealed that the electrical performance of the IZO TFTs is dependent on the concentration of precursor solution. As well, the optimum preparation process was obtained. The concentrations induced the regulation of the electronic performance was clearly demonstrated with a proposed mechanism. The results are expected to be beneficial for development of solution-processed metal oxide TFTs.