L-arginine and N-carbamoylglutamic acid supplementation enhance young rabbit growth and immunity by regulating intestinal microbial community

Sun, Xiaoming,Shen, Jinglin,Liu, Chang,Li, Sheng,Peng, Yanxia,Chen, Chengzhen,Yuan, Bao,Gao, Yan,Meng, Xianmei,Jiang, Hao,Zhang, Jiabao Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.1

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

Phenomenon of Active Power Consumption by the Inductors in Voltage Source Converters Dominated Power Systems

Hui Yang,Xiaoming Yuan 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Accompanied by the increasing penetration of grid-connected voltage source converters (VSCs) in modern power systems, the related oscillatory phenomena are discovered. To analyze the mechanisms of such oscillations, making clear the power exchanging characteristics as well as the power transporting characteristics of various elements in power systems is the basis. The related studies usually regarded that only the resistors in AC grid consume active power during dynamics. However, in this paper, the phenomenon that the inductors will also consume active power during dynamics is found. And what"s more, the active power consumed by the inductors may even lead to the instability of system in some cases. To analyze the cause for the found phenomenon, the external characteristics of VSC seen from the grid is concerned, which can be described with a voltage source whose amplitude and frequency are both time-varying. Through analysis in this paper, it is mainly the frequency variation of the equivalent voltage source that bring in the phenomenon. All the results have been validated through the time-domain simulations. The found phenomenon and analysis will update the existing understanding about mechanisms of oscillations related to VSCs.

A Learning-based Power Control Scheme for Edge-based eHealth IoT Systems

( Haoru Su ),( Xiaoming Yuan ),( Yujie Tang ),( Rui Tian ),( Enchang Sun ),( Hairong Yan ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.12

The Internet of Things (IoT) eHealth systems composed by Wireless Body Area Network (WBAN) has emerged recently. Sensor nodes are placed around or in the human body to collect physiological data. WBAN has many different applications, for instance health monitoring. Since the limitation of the size of the battery, besides speed, reliability, and accuracy; design of WBAN protocols should consider the energy efficiency and time delay. To solve these problems, this paper adopt the end-edge-cloud orchestrated network architecture and propose a transmission based on reinforcement algorithm. The priority of sensing data is classified according to certain application. System utility function is modeled according to the channel factors, the energy utility, and successful transmission conditions. The optimization problem is mapped to Q-learning model. Following this online power control protocol, the energy level of both the senor to coordinator, and coordinator to edge server can be modified according to the current channel condition. The network performance is evaluated by simulation. The results show that the proposed power control protocol has higher system energy efficiency, delivery ratio, and throughput.

Stability and Adaptability Analysis for PLL-Synchronized VSC-HVDC with Frequency Regulation Scheme under Islanded Grid

Meiqing Zhang,Xiaoming Yuan,Jiabing Hu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Voltage-source converter (VSC) high voltage direct current (HVDC) connected to islanded grid is becoming a normal system operation mode. However, there is little research on the stability analysis of VSC-HVDC connected to islanded grid. On the basis of previous work, this paper analyzes the stability and adaptability of PLL-synchronized VSC-HVDC adopted with the additional frequency regulation scheme (FRS) under islanded grid. By defining the instantaneous frequency and regarding it as a state variable, the small-signal model of PLL-synchronized VSC under both grid-islanded mode and grid-connected mode is synthetically established. On this basis, the impact of FRS on the stability of PLL-synchronized VSC under islanded grid is analyzed, and then the adaptability of FRS to different grid strengths is investigated via considering different short current ratios (SCRs), including islanded grid (SCR=0), weak grid (SCR<2) and strong grid (SCR>5). The analysis results show that the FRS has important role on enhancing the small signal stability of the islanded grid, and also has excellent adaptability to the wide change of grid conditions, so as to further improve the possibility of the FRS applied in practical projects. These results finally are verified by time-domain simulations.

A New Cassane-type Diterpene and Other Constituents from Caesalpinia minax

Liu, Huiling,Ma, Guoxu,Yuan, Jingquan,Tan, Xiaoming,Zheng, Qingxia,Sun, Zhaocui,Yang, Junshan,Xu, Xudong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

Damage monitoring of variable cross-section region in a column-drilled shaft assembly using smart aggregates

Jie Tan,Mahadi Masud,Xiaoming Qin,Cheng Yuan,Qingzhao Kong,Y.L.Mo 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.5

Pier column, as the most critical load-bearing member of bridge, can bear multiple loads including axial forces,shear forces, bending moments, etc. The varied cross section at the column interface and bearing platform or drilled shaft leads to harmful stress concentration that can potentially compromise the structural integrity. In order to improve the ductility of bridge structure, a pier column is often designed with a variable cross-section region to dissipate energy through plastic deformation. For better understanding the health condition of pier column in its service life, it is of great significance to obtain the damage severity information in the variable cross-section region. This study utilizes an active sensing method enabled by distributed Lead Zirconate Titanate (PZT)-based Smart Aggregate (SA) sensors to monitor the damage initiation and development near the bottom of a pier column. Crack damage in variable cross-section region functions as a stress relief that attenuates propagating stress wave energy between SA pairs. Both the numerical and experimental results show that the reduction ratio of the stress wave energy is consistent with the crack development, thus validating the reliability of the investigated approach. SA-based technology can be used as a potential tool to provide early warning of damage in variable cross-section region of bridge structures.

Energy-efficient Relay MAC with Dynamic Power Control in Wireless Body Area Networks

( Xuelian Cai ),( Jingjing Yuan ),( Xiaoming Yuan ),( Wu Zhu ),( Jiandong Li ),( Changle Li ),( Sana Ullah ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.7

Wireless body area network (WBAN) is an emerging short-range wireless communication network with sensor nodes located on, in or around the human body for healthcare, entertainment and ubiquitous computing. In WBANs, energy is severely constrained which is the prime consideration in the medium access control (MAC) protocol design. In this paper, we propose a novel MAC protocol named Energy-efficient Relay MAC with dynamic Power Control (ERPC-MAC) to save energy consumption. Without relying on the additional devices, ERPC-MAC employs relaying nodes to provide relay service for nodes which consume energy fast. Accordingly the superframe adjustment is performed and then the network topology can be smoothly switched from single-hop to multi-hop. Moreover, for further energy saving and reliability improvement, the dynamic power control is introduced to adjust the power level whenever a node transmits its packets to the coordinator or the relaying node. To the best of the authors` knowledge, this is the first effort to integrate relay, topology adjustment and power control to improve the network performance in a WBAN. Comprehensive simulations are conducted to evaluate the performance. The results show that the ERPC-MAC is more superior to the existing standard and significantly prolongs the network lifetime.

A New Cassane-type Diterpene and Other Constituents from Caesalpinia minax

Huiling Liu,Guoxu Ma,Jingquan Yuan,Xiaoming Tan,Qingxia Zheng,Zhaocui Sun,Junshan Yang,Xudong Xu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.5