Mechanism underlying 2n male and female gamete formation in lemon via cytological and molecular marker analysis

Kai‑Dong Xie,Qiang‑Ming Xia,Jun Peng,Xiao‑Meng Wu,Zong‑Zhou Xie,Chun‑Li Chen,Wen‑Wu Guo 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.2

The unreduced (2n) gametes have long been used in triploid breeding of citrus. In lemon, the previously reported mechanisms for 2n megagametophyte formation were controversial, whereas that for 2n pollen production is still unknown. Herein, the frequency of and mechanism underlying 2n megagametophyte and 2n pollen formation in ‘Eureka’ lemon were investigated based on cytological observation and genotyping of the triploid hybrids between ‘Eureka’ lemon and ‘Early gold’ sweet orange. As a result, 4.79% of the viable pollens of ‘Eureka’ lemon were identified as the 2n pollen with a larger diameter (70.16 ± 3.92 μm). The 2n pollen might be resulted from the formation of parallel spindles at meiosis stage II. Among the 204 plantlets regenerated from embryo rescue following the sexual cross, 12 were triploids as identified by flow cytometry. According to the analysis of heterozygosity transmission using 13 pericentromeric single nucleotide polymorphism (SNP) markers and 20 randomly distributed simple sequence repeat (SSR) markers, 11 triploids were identified to be originated from the fertilization of 2n megagametophytes of ‘Eureka’ lemon, with a frequency of 5.39%. Among them, nine 2n megagametophytes were supposed to be arisen from the second division restitution (SDR), whereas the other two were from postmeiotic genome doubling (PMD). These results to understand the mechanism underlying 2n gamete formation in lemon are valuable for its efficient polyploid breeding.

Biological Potential of Bioorganic Fertilizer Fortified with Bacterial Antagonist for the Control of Tomato Bacterial Wilt and the Promotion of Crop Yields

( Kai Wu ),( Zhiying Fang ),( Lili Wang ),( Saifei Yuan ),( Rong Guo ),( Biao Shen ),( Qirong Shen ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.10

The application of Bacillus sp. in the biological control of plant soilborne diseases has been shown to be an environmentally friendly alternative to the use of chemical fungicides. In this study, the effects of bioorganic fertilizer (BOF) fortified with Bacillus amyloliquefaciens SQY 162 on the suppression of tomato bacterial wilt were investigated in pot experiments. The disease incidence of tomato wilt after the application of BOF was 65.18% and 41.62% lower at 10 and 20 days after transplantation, respectively, than in the control condition. BOF also promoted the plant growth. The SQY 162 populations efficiently colonized the tomato rhizosphere, which directly suppressed the number of Ralstonia solanacearum in the tomato rhizosphere soil. In the presence of BOF, the activities of defense-related enzymes in tomato were lower than in the presence of the control treatment, but the expression levels of the defense-related genes of the plants in the salicylic acid and jasmonic acid pathways were enhanced. It was also found that strain SQY 162 could secrete antibiotic surfactin, but not volatile organic compounds, to suppress Ralstonia. The strain could also produce plant growth promotion compounds such as siderophores and indole-3-acetic acid. Thus, owing to its innate multiple-functional traits and its broad biocontrol activities, we found that this antagonistic strain isolated from the tobacco rhizosphere could establish itself successfully in the tomato rhizosphere to control soilborne diseases.

Experimental Study on Mechanical Behavior of Prefabricated PEC Composite Beams Under Cyclic Loading

Kai Wu,Shi qi Lin,Xiaoyi Liu,Fanshen Mao,Jiangpeng Zhai 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.3

In this paper, a new type prefabricated partially encased composite beam (PEC beam) using screw arbors instead of stirrups or welded transverse links in ordinary PEC structures to connect the upper and lower steel fl ange has been proposed. It not only retains the performance advantages of PEC structures, but also greatly enhances the prefabricated degree of structure and simplifi es construction process. Twelve beams with and without screw arbors were tested under cyclic loading to study the mechanical behavior of this new type of PEC beams. The major factors considered were shear span ratio ( λ = 1.0, 2.0, 3.0 and 4.0), with or without screw arbors and concrete thickness. Test results including failure mode, load–defl ection curves ( P − Δ curves), characteristic points, ductility and stiff ness were introduced and discussed in detail. The test results showed that the failure mode of PEC beams changed from shear failure to bending failure with the increase of shear span ratio, and the asymmetric damage of specimens can be improved by screw arbors. In addition, PEC beams with screw arbors have better ductility and slower stiff ness degeneration than those without screw arbors. Potential application value can be seen from this new type of prefabricated PEC beams.

Effect of Impact Energy on the Impact-Wear Properties of High Manganese Steels in Acidic Corrosive Conditions

( Kai Wang ),( Xiao Dong Du ),( Kai Wu ),( Kuk Tae Youn ),( Chan Gyu Lee ),( Bon Heun Koo ) 한국부식방식학회(구 한국부식학회) 2008 Corrosion Science and Technology Vol.7 No.6

MicroRNA-146a Enhances Helicobacter pylori Induced Cell Apoptosis in Human Gastric Cancer Epithelial Cells

Wu, Kai,Yang, Liu,Li, Cong,Zhu, Chao-Hui,Wang, Xin,Yao, Yi,Jia, Yu-Jie Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Helicobacter pylori (H. pylori) infection induces apoptosis in gastric epithelial cells, and this occurrence may link to gastric carcinogenesis. However, the regulatory mechanism of H. pylori-induced apoptosis is not clear. MicroRNA-146a has been implicated as a key regulator of the immune system. This report describes our discovery of molecular mechanisms of microRNA-146a regulation of apoptosis in human gastric cancer cells. We found that overexpression of microRNA-146a by transfecting microRNA-146a mimics could significantly enhance apoptosis, and this upregulation was triggered by COX-2 inhibition. Furthermore, we found that microRNA-146a density was positively correlated with apoptosis rates in H. pylori-positive gastric cancer tissues and intratumoral microRNA-146a density was negatively correlated with lymph node metastasis among H. pylori-positive gastric cancer patients. Understanding the important roles of microRNA-146a in regulating cell apoptosis in H. pylori infected human gastric cancer cells will contribute to the development of microRNA targeted therapy in the future.

Mixed H2/H∞ Control for Linear Infinite-Dimensional Systems

Kai-Ning Wu,Baozhu Guo,Weihai Zhang,Bor-Sen Chen 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.1

In this paper, we consider mixed H2=H∞ control problems for linear infinite-dimensional systems. Thefirst part considers the state feedback control for the H2=H∞ control problems of linear infinite-dimensional systems. The cost horizon can be infinite or finite time. The solutions of the H2=H∞ control problem for linear infinitedimensionalsystems are presented in terms of the solutions of the coupled operator Riccati equations and coupleddifferential operator Riccati equations. The second part addresses the observer-based H2=H∞ control of linearinfinite-dimensional systems with infinite horizon and finite horizon costs. The solutions for the observer-basedH2=H∞ control problem of linear infinite-dimensional systems are represented in terms of the solutions of coupledoperator Riccati equations. The first-order partial differential system examples are presented for illustration. Inparticular, for these examples, the Riccati equations are represented in terms of the coefficients of first-order partialdifferential systems.

Experimental study on shear damage and lateral stiffness of transfer column in SRC-RC hybrid structure

Kai Wu,Jiangpeng Zhai,Jianyang Xue,Fangyuan Xu,Hongtie Zhao 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.5

A low-cycle loading experiment of 16 transfer column specimens was conducted to study the influence of parameters, likes the extension length of shape steel, the ratio of shape steel, the axial compression ratio and the volumetric ratio of stirrups, on the shear distribution between steel and concrete, the concrete damage state and the degradation of lateral stiffness. Shear force of shape steel reacted at the core area of concrete section and led to tension effect which accelerated the damage of concrete. At the same time, the damage of concrete diminished its shear capacity and resulted in the shear enlargement of shape steel. The interplay between concrete damage and shear force of shape steel ultimately made for the failures of transfer columns. With the increase of extension length, the lateral stiffness first increases and then decreases, but the stiffness degradation gets faster; With the increase of steel ratio, the lateral stiffness remains the same, but the degradation gets faster; With the increase of the axial compression ratio, the lateral stiffness increases, and the degradation is more significant. Using more stirrups can effectively restrain the development of cracks and increase the lateral stiffness at the yielding point. Also, a formula for calculating the yielding lateral stiffness is obtained by a regression analysis of the test data.

The Image of LU XUN in the Japanese Mandarin Textbook of Japanese Middle School

WU Kai 한국문학과종교학회 2016 한국문학과종교학회 국제학술대회 Vol.2016 No.07

被誉为“国民作家”的鲁迅,其作品深受日本人民的喜爱。1909年,日本文字媒体首次将这位“思想战 士”“文学英豪”予以报道24)。尔后,通过各期日本“鲁研学者”相继努力,时至今日,仍可断言:作为中 华民族文化的“宣扬者”的他在日本列岛上依旧闪耀着灿烂的光辉;他的文字如同甘醇的美酒,让人品味 无穷。无论中日两国,中小学语文课本成为播撒“鲁迅种子”的第一块阵地。通过鲁迅作品的解读与教 学,不仅提高了国民语言工具的运用能力,同时也普及了文学知识、洗礼了精神世界。 25)在隔海相望 的日本,首部鲁迅译作问世于20世纪20年代,收录进国语课本中的鲁迅作品也均是经名家之手的翻译 佳作。整理日本中学国语教科书中的鲁迅作品收录情况和分析收录背景、解读教参、分析出现的“鲁迅 习题”“鲁迅试题”等,一方面非常有利于洞悉“鲁迅精神”在日本基础教育领域的普及与接受情况;亦对 中国中学语文课的“鲁迅教学”及大学日语专业“中日对比文学”教学与研究有深刻的借鉴、指导意义。

Experimental Study and Degradation Analysis on Interfacial Shear Modulus of Steel and Steel Fiber-Reinforced Concrete Composite Structure

Kai Wu,Shiyuan Qian,Huiming Zheng,Yukai Zhou,Fangzhou Guo 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.8

To address the problems of mutual interference between shaped steel and reinforcement bars and the difficulty of concrete pouring in the construction of steel-reinforced concrete (SRC) composite structure, the steel and steel fiber-reinforced concrete (SSFRC) composite structure without rebars was proposed. Bond behavior between the shaped steel and steel fiber reinforced concrete is the basis to ensure two kinds of materials work together. 20 square specimens were designed and tested by push-out test to study the bond performance and shear modulus of the interface between the shaped steel and steel fiber reinforced concrete. The effects of steel fiber ratio (ρsf), embedded length (Le), and concrete cover thickness (Css) on the interfacial shear modulus (G) were analyzed quantitatively. The degradation law of G was studied by defining the degradation variable of interfacial shear modulus (Da). The results show that the increase of ρsf contributes to the ascent in G, and the loading end displacement (D) at the end of degradation related to G also increase. With the rise of Le, the value of Gdecreases gradually and the D becomes larger when G starts to deteriorate. In addition, there is a positive correlation between G and Css. Besides, the higher Css leads to a slower degradation process of G.

Experimental research on seismic behavior of SRC-RC transfer columns

Kai Wu,Jianyang Xue,Yang Nan,Hongtie Zhao 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

It was found that the lateral stiffness changes obvious at the transfer position of the section configuration from SRC to RC. This particular behavior leads to that the transfer columns become as the important elements in SRC-RC hybrid structures. A comprehensive study was conducted to investigate the seismic behavior of SRC-RC transfer columns based on a low cyclic loading test of 16 transfer columns compared with 1 RC column. Test results shows three failure modes for transfer columns, which are shear failure, bond failure and bend failure. Its seismic behavior was completely analyzed about the failure mode, hysteretic and skeleton curves, bearing capacity deformation ability, stiffness degradation and energy dissipation. It is further determined that displacement ductility coefficient of transfer columns changes from 1.97 to 5.99. The stiffness of transfer columns are at the interval of SRC and RC, and hence transfer columns can play the role of transition from SRC to RC. All specimens show similar discipline of stiffness degradation and the process can be divided into three parts. Some specimens of transfer column lose bearing capacity swiftly after shear cracking and showed weak energy dissipation ability, but the others show better ability of energy dissipation than RC column.