Hypoglycemic Effects of Ganoderma lucidum Polysaccharides in Type 2 Diabetic Mice

Chun Xiao,Qingping Wu,Xiao-Bing Yang,Wen Cai,Jian-Bin Tan,Jumei Zhang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.10

Our aims were to investigate the hypoglycemic effects and mechanisms of action of Ganoderma lucidum polysaccharides (GLPs) administered for 7 days in type 2 diabetic mice. The mice were randomly divided into four groups (8 mice/group): normal control group, diabetic control group, low-dose GLP-treated diabetic group (50 mg/kg/d), and high-dose GLP-treated diabetic group (100 mg/kg/d). Diabetes was induced by streptozotocin injection and high-fat dietary feeding. At the end of the study, fasting serum glucose, insulin, body weight (BW) and epididymal white adipose tissue weight were measured. The hepatic mRNA levels of glycogen phosphorylase (GP), fructose-1,6-bisphosphatase (FBPase), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) genes were determined by real-time polymerase chain reaction. Both doses of GLPs significantly decreased fasting serum glucose, insulin and epididymal fat/BW ratio compared with the diabetic control group (p < 0.05). The hepatic mRNA levels of GP, FBPase, PEPCK and G6Pase were significantly lower in both GLP-treated groups compared with the diabetic control group. Taken together, GLPs significantly decrease fasting serum glucose levels in type 2 diabetic mice in a dose-dependent manner. The decreases in fasting serum glucose levels may be associated with decreased mRNA expression levels of several key enzymes involved in gluconeogenesis and/or glycogenolysis.

Property Studies of Optical Waveguide Formed by keV He-Ion Implanted into a Nd:CNGG Crystal

Chunxiao Yu,Jin-Hua Zhao,Huai-Jin Zhang,Xue-Lin Wang 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

A planar optical waveguide was formed in a neodymium-doped calcium niobium gallium garnet (Nd:CNGG) crystal by using 500-keV He-ion implantation with a dose of 2 × 1016 ions/cm2 at room temperature. The dark modes were observed by using a prism coupling method, and the refractive index profile was reconstructed using a reflectivity calculation method (RCM). The SRIM2006 code (stopping and range of ions in matters, code 2006) was used to simulate the damage profile in the ion-implanted sample. The photoluminescence spectra of the samples showed fairly good potential for used as a laser waveguide.

Color Image Compression Based on Directional All Phase Biorthogonal Transform

Chunxiao Zhang,Chengyou Wang,Baochen Jiang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

There are images in which some directional edges other than the vertical or horizontal ones dominate. So the conventional discrete cosine transform (DCT) may not be the best choice for them. Directional DCT framework is able to provide a better coding performance for image blocks that contain directional edges. In addition, the all phase biorthogonal transform (APBT) algorithm can improve the performance of compression. In the light of directional DCT and APBT, directional APBT is proposed and applied to color image coding. Experimental results show that this framework can indeed improve the compression performance of color image remarkably.

Ferulic acid protects cardiomyocytes from TNF-a/cycloheximide-induced apoptosis by regulating autophagy

Chunxiao Li,Lu Chen,Min Song,Zhirui Fang,Lusha Zhang,Joel Wake Coffie,Liyuan Zhang,Lulu Ma,Qianyi Wang,Wenjie Yang,Leyu Fang,Shaoxia Wang,Xiumei Gao,Hong Wang 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.8

Acute myocardial infarction (AMI) resultsin irreversible cardiac cell damage or death because ofdecreased blood fl ow to the heart. Apoptosis plays an importantrole in the process of tissue damage after myocardialinfarction (MI), which has pathological and therapeuticimplications. Ferulic acid (FA) is a phenolic acid endowedwith strong antioxidative and cytoprotective activities. Thepresent study aimed to investigate whether FA protectscardiomyocytes from apoptosis by regulating autophagy,which is a cellular self-digestion process, and one of thefi rst lines of defense against oxidative stress. Apoptosis wasinduced by TNF-α (10 ng/mL) and cycloheximide (CHX,5 μg/mL) in rat H9c2 cardiomyocytes. FA-inhibited TNF-α/CHX-induced apoptosis was determined by the quantifi cationof TUNEL-positive cells, and the eff ect was associatedwith decreased ROS production and inhibited caspase3activation. FA treatment enhanced autophagy and increasedautophagy-associated protein expression, leading to an inhibitionof mTOR signaling. When co-treated with 3-methyladenine(3-MA), an autophagy inhibitor, the anti-apoptoticeff ect of FA was attenuated. In an in vivo mouse MI model,FA treatment decreased the apoptotic cell number, reducedinfarct size, and improved cardiac performance, as determinedby histological and echocardiographic assessments. Taken collectively, these results suggest that FA could protectcardiomyocytes from apoptosis by enhancing autophagy.

Barrier Lyapunov Function Based Adaptive Cross Backstepping Control for Nonlinear Systems with Time-varying Partial State Constraints

Chunxiao Wang,Lu Qi,Jia-yun Liu,Jia-li Yu 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7

This paper focuses on an adaptive cross-backstepping control for a class of nonstrict-feedback nonlinear systems affected by time-varying partial state constraints. The nonstrict-feedback nonlinear systems considered in this paper are divided into two strict-feedback nonlinear subsystems. One constrained subsystems and another unconstrained subsystems. In view of the normal backstepping method is only an effective method to control lowertriangular systems, cross-backstepping control is introduced which successfully solves the problem of alternatetime-varying state constraints. For the constrained subsystems, novel time-varying tan-type barrier Lyapunov function (TBLF) is employed in each step of backstepping design to guarantee the boundedness of the fictitious or actual state tracking errors. Besides, proper adaptive laws are designed for the upper bound of uncertain parameters, which successfully neutralize the influence of parametric uncertainties. Based on the stability analysis, it is concluded that the states of the closed-loop system maintain in the predefined time-varying compact sets and the output can be guaranteed to be as close to the desired trajectory as possible. The effectiveness of the proposed technique is illustrated by a constrained hyperchaotic system in two cases.

Some New Results on Uncertain Age Replacement Policy

Chunxiao Zhang,Congrong Guo 대한산업공학회 2013 Industrial Engineeering & Management Systems Vol.12 No.1

Age replacement policy is a commonly policy in maintenance management of spare part. It means that a spare part is always replaced at failure or fixed time after its installation, whichever occurs first. An optimal age replacement policy of spare parts concerns with finding the optimal replacement time determined by minimizing the expected cost per unit time. The age of the part was generally assumed to be a random variable in the past literatures, but in many situations, there are few or even no observed data to estimate the probability distribution of part’s lifetime. In order to solve this phenomenon, a new uncertain age replacement policy has been proposed recently, in which the age of the part was assumed to be an uncertain variable. This paper discusses the optimal age replacement policies by dealing with the parts’ lifetimes as different distributed uncertain variables. Several results on the optimal age replacement time are provided when the lifetimes are described by the uncertain linear, zigzag and lognormal distributions.

Video Compression Algorithm Based on Directional All Phase Biorthogonal Transform and H.263

Chunxiao Zhang,Chengyou Wang,Baochen Jiang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.3

The vertical or horizontal edges don’t dominate in some frames of video sequence, so the conventional discrete cosine transform (DCT) may not be the best choice for those frames. Directional DCT framework behaves better than conventional DCT in coding performance for images where directional edges dominate. In addition, the all phase biorthogonal transform (APBT), which is used in image compression instead of DCT, can also help to improve the performance of compression. In the light of directional DCT and APBT, directional APBT (D- APBT) is proposed and applied to H.263 video coding. Experimental results show that this framework can indeed improve the coding performance remarkably.

Barrier Lyapunov Functions-based Adaptive Control for Nonlinear Purefeedback Systems with Time-varying Full State Constraints

Chunxiao Wang,Yu-Qiang Wu,Jiang-Bo Yu 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

This paper studies the problem of controller design for pure-feedback nonlinear systems with asymmetrictime-varying full state constraints. The mean value theorem is employed to transform a pure-feedback system intoa strict-feedback structure with non-affine terms. For the transformed system, a time-varying asymmetric BarrierLyapunov Function (ABLF) with the error variables is employed to ensure the time-varying constraints satisfaction. By allowing the barriers to vary with the desired trajectory in time, the initial condition requirements are relaxedefficiently. The presented control scheme can guarantee that all signals in the closed-loop system are ultimatelybounded. It is also proved that the tracking error converges to an adjustable neighborhood of the origin even in thepresence of disturbance. The performance of the ABLF-based control are illustrated through two examples.

Prediction Model of Net Cutting Specific Energy Based on Energy Flow in Milling

Chunxiao Li,Guoyong Zhao,Yugang Zhao,Shuang Xu,Zhifu Zheng 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.5

Net cutting specific energy ( NCSE ) reflects the actual cutting energy efficiency. Establishing a NCSE prediction model is helpful to analyze the energy consumption characteristics of machine tools. As so far, few studies have focused on the NCSE prediction in the way of energy flow. Therefore, based on the flow direction of cutting energy, a mathematical model for predicting NCSE is proposed in this paper. During milling, the energy used for cutting can be divided into forming surface energy, material removing energy and additional load energy. Thus, the NCSE model is decomposed into three sub-models. Firstly, in the cutting process of AISI 304 stainless steel, the phase transition of austenite to martensite on the machined surface is induced by parts of cutting energy, and then work hardening occur. Furthermore, the forming surface specific energy prediction model is established based on surface hardness. Secondly, the models of material removing energy and additional load energy are developed respectively with the material removal rate and spindle speed. The above sub-models are integrated into the NCSE prediction model with the determination coefficient R 2 of 0.982, and average prediction accuracy of 96.77%. Finally, the influence of input variables on NCSE and the energy consumption proportion are revealed. Among them, the forming surface specific energy, material removing specific energy and additional load specific energy account for 8.26%, 32.63% and 59.11% on NCSE respectively. The proposed model can not only predict the overall cutting energy consumption, but also predict the energy consumption of each sub-model. The research provides a new idea for analyzing cutting energy characteristics and improving processing theory.

An Measurement Investigation of the Crossflow Characteristics through the Liner Holes in a Model Gas Turbine Combustor

Chunxiao Xu,Sangho Lee,Jeekeun Lee 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

An experimental investigation of discharge coefficient of a single round hole and jet into crossflow has been conducted with application to an annular-type gas turbine combustor. 2 parallel contiguous ducts of rectangular cross section were used for simulating a sector of an annular combustor. Mass flow and total pressure and static pressure were measured by orifice flowmeter and pressure taping. The characteristics of jet into crossflow were investigated by using PIV system. Results show that the discharge coefficient decreased increasing the distance between hole and turbine entrance and increasing the main flow velocity. Swirling flow producted an effect on the discharge coefficient and jet penetration at a low jet Reynolds but when jet flow becomes stronger, the effect of swirling flow field was negligible.