Genetic transformation of wheat: current status and future prospects

Jiarui Li,Xingguo Ye,Baoyan An,Lipu Du,Huijun Xu 한국식물생명공학회 2012 Plant biotechnology reports Vol.6 No.3

Genetic transformation is a reverse genetics tool for validation of target genes and crop improvement. However, due to its low efficiency and genotype dependency,wheat is considered a recalcitrant plant for genetic transformation. During the last 20 years, various in vitro and in planta transformation methods have been reported in wheat. Until now, biolistic particle and Agrobacteriummediated wheat transformation methods using immature embryos as explants have been the two major transformation approaches. In addition to immature embryos, other explant types, such as mature embryos, anther-derived calli, inflorescences, apical meristems, and other floral organs, have been employed; however, they need further optimization. In addition to the common marker genes,such as bar, hpt and gus, other effective markers, ALS,AtMYB12 and pmi, have been successfully used for selection of positive transgenic plants. Numerous agronomic trait genes such as biotic stress resistance or tolerance genes have been transferred into wheat plants. Future prospects, such as recipient wheat cultivars and explants,marker free issues, and transgene silencing, are discussed. The objective of this review is to summarize current successful techniques for wheat transformation and stimulate further research into long-term wheat improvement by genetic engineering approaches.

Cutting force and machine kinematics constrained cutter location planning for five-axis flank milling of ruled surfaces

Ke Xu,Jiarui Wang,Chih-Hsing Chu,Kai Tang 한국CDE학회 2017 Journal of computational design and engineering Vol.4 No.3

Five-axis flank milling has been commonly used in the manufacturing of complex workpieces because of its greater productivity than that of three-axis or five-axis end milling. The advantage of this milling operation largely depends on effective cutter location planning. The finished surface sometimes suffers from large geometrical errors induced by improper tool positioning, due to the non-developability of most ruled surfaces in industrial applications. In addition, a slender flank-milling cutter may be deflected when subjected to large cutting forces during the machining process, further degrading the surface quality or even breaking the cutter. This paper proposes a novel tool path planning scheme to address those problems. A simple but effective algorithm is developed to adaptively allocate a series of cutter locations over the design surface with each one being confined within an angular rotation range. The allocation result satisfies a given constraint of geometrical errors on the finished surface, which consists of the tool positioning errors at each cutter location and the sweeping errors between consecutive ones. In addition, a feed rate scheduling algorithm is proposed to maximize the machining efficiency subject to the cutting force constraint and the kinematical constraints of a specific machine configuration. Simulation and experimental tests are conducted to validate the effectiveness of the proposed algorithms. Both the machining efficiency and finish surface quality are greatly improved compared with conventional cutter locations.

Parametric analysis on diagonal bracing joints connected with self-tapping screw

Zhenhua Xu,Guoliang Bai,Biao Liu,Jiarui Li,Yifan Yang 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.1

In this paper, a three-dimensional finite element model (FEM) was established to study the performance of sliding resistance on the diagonal bracing joints of prefabricated steel frame (PSF) connected with self-tapping screw. In addition, the load-displacement curves of the joints were well verified by the test results, and a parametric study was conducted using the validated models to investigate the effect of steel grade, thickness of the tapped plate, the margin of bolt hole, the end and the central distance of bolt hole. The results showed that with the increase of steel grade, thickness of the tapped plate and the distance of the bolt holes, the anti-slide stiffness and the ultimate bearing capacity of the joint were significantly improved. It was recommended that steel grade should be Q345, Q390 or above. It was advisable to take the thickness of the tapped plate at 0.7d0 ~ 1.0d0, take the margin of bolt hole at 1.2d0 ~ 1.6d0, the central and the end distance of bolt hole should be greater than 2.0d0 and 1.2d0, respectively. The results could provide reference for engineering design.

Identification and Validation of Circulating MicroRNA Signatures for Breast Cancer Early Detection Based on Large Scale Tissue-Derived Data

Xiaokang Yu,Jinsheng Liang,Jiarui Xu,Xingsong Li,Shan Xing,Huilan Liu,Wan-Li Liu,Dongdong Liu,Jianhua Xu,Lizhen Huang,Hongli Du 한국유방암학회 2018 Journal of breast cancer Vol.21 No.4

Purpose: Breast cancer is the most commonly occurring cancer among women worldwide, and therefore, improved approaches for its early detection are urgently needed. As microRNAs (miRNAs) are increasingly recognized as critical regulators in tumorigenesis and possess excellent stability in plasma, this study focused on using miRNAs to develop a method for identifying noninvasive biomarkers. Methods: To discover critical candidates, differential expression analysis was performed on tissue-originated miRNA profiles of 409 early breast cancer patients and 87 healthy controls from The Cancer Genome Atlas database. We selected candidates from the differentially expressed miRNAs and then evaluated every possible molecular signature formed by the candidates. The best signature was validated in independent serum samples from 113 early breast cancer patients and 47 healthy controls using reverse transcription quantitative real-time polymerase chain reaction. Results: The miRNA candidates in our method were revealed to be associated with breast cancer according to previous studies and showed potential as useful biomarkers. When validated in independent serum samples, the area under curve of the final miRNA signature (miR-21-3p, miR-21-5p, and miR-99a-5p) was 0.895. Diagnostic sensitivity and specificity were 97.9% and 73.5%, respectively. Conclusion: The present study established a novel and effective method to identify biomarkers for early breast cancer. And the method, is also suitable for other cancer types. Furthermore, a combination of three miRNAs was identified as a prospective biomarker for breast cancer early detection.

Modified Model Free Adaptive Control for a Class of Nonlinear Systems with Multi-threshold Quantized Observations

Xiangquan Li,Zhengguang Xu,Yanrong Lu,Jiarui Cui,Lixin Zhang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

This paper addresses a pattern-moving-based modified model free adaptive control (PMFAC) scheme and illustrates the convergence of its tracking error for a class of nonlinear systems with unknown model and multi-threshold quantized observations. The basic idea is to consider the system’s quantization error as an external disturbance and an improved performance index function of control law is proposed from the perspective of twoplayer zero-sum game (TP-ZSG) based on the existed MFAC algorithms. The PMFAC scheme is established which mainly includes an improved tracking control law and a pseudo-partial derivative (PPD) estimation algorithm. Under certain conditions, the bounded convergence of system tracking error and the stability of PMFAC system with quantization errors can be guaranteed. The theoretical results are demonstrated by two numerical examples.

Pattern-moving-based Robust Model-free Adaptive Control for a Class of Nonlinear Systems with Disturbance and Data Dropout

Xiangquan Li,Zhengguang Xu,Cheng Han,Jiarui Cui 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

The ability to deal with the system disturbance and/or data dropout is often referred to as the robustness of model-free or data-driven control theory. This paper addresses a novel pattern-moving-based partial-form dynamic linearization intermittent model-free adaptive control scheme for a class of nonlinear discrete-time systems with disturbance and random measurement data dropout. Furthermore, the bounded convergence of the tracking error of the closed-loop system is proved by the statistical approach with contraction mapping principle. The basic idea is to consider the pattern-moving-based partial-form dynamic linearization model-free adaptive control method under the condition of missing data which may be caused by network failure, failing sensor or actuator. The designed scheme mainly includes an improved intermittent tracking control law, an intermittent classification-metric bias estimation algorithm and a modified intermittent pseudo gradient vector estimation algorithm. The bounded convergence and effectiveness of the proposed scheme are demonstrated by both the rigorous mathematical inference and two numerical examples.

Experimental and Mechanism Investigation on Boiling Heat Transfer Characteristics of Alumina/Water Nanofluid on a Cylindrical Tube

Hao Zhang,Zeng-en Li,Shan Qing,Zhuangzhuang Jia,Jiarui Xu,Lin Ma,Sixian Wang,Aimin Zhang,Zhumei Luo 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.10

Nucleate pool boiling heat transfer experiments have been conducted to nanofluids on a horizontal cylinder tube under atmospheric pressure. The nanofluids are prepared by dispersing Al2O3 nanoparticles into distilled water at concentrations of 0.001, 0.01, 0.1, 1 and 2 wt.% with or without sodium, 4-dodecylbenzenesulfonate (SDBS). The experimental results showed that: nanofluids at lower concentrations (0.001 wt.% to 1 wt.%) can obviously enhance the pool boiling heat transfer performance, but signs of deterioration can be observed at higher concentration (2 wt.%). The presence of SDBS can obviously enhance the pool boiling heat transfer performance, and with the presence of SDBS, a maximum enhancement ratio of BHTC of 69.88%, and a maximum decrease ratio of super heat of 41.12% can be found in Group NS5 and NS4, respectively. The tube diameter and wall thickness of heating surface are the influential factors for boiling heat transfer coefficient. Besides, we find that Rohsenow formula failed to predict the characteristics of nanofluids. The mechanism study shows that: the decrease of surface tension, which leads to the decrease of bubble departure diameter, and the presence of agglomerates in nanofluids are the reasons for the enhanced pool boiling heat transfer performance. At higher concentration, particle deposition will lead to the decrease of distribution density of the vaporization core, and as a result of that, the boiling heat transfer performance will deteriorate.

Dynamic strain control of transformations between different structure phases of freestanding oxide membrane

Woo Jin Kim,Varun Harbola,Yonghun Lee,Kevin J. Crust,Ruijuan Xu,Bai Yang Wang,Yijun Yu,Jiarui Li,Harold Y. Hwang 대한용접·접합학회 2023 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2023 No.10