Antidiabetic Effects of Corni Fructus Extract in Streptozotocin-Induced Diabetic Rats

Dawei Gao,Qingwang Li,Zhengrong Gao,Lixin Wang 연세대학교의과대학 2012 Yonsei medical journal Vol.53 No.4

Purpose: Diabetes is the leading cause of end-stage renal failure. The present study was undertaken to characterize the effects of Corni Fructus on diabetic nephropathy in streptozotocin-induced diabetic rats and their mechanisms. Materials and Methods:Streptozotocin-diabetic rats were orally administrated with Corni Fructus at a dose of 100, 200 or 400 mg/kg body mass for 40 days. Results: Corni Fructus-treated diabetic rats showed significant decreases of blood glucose, urinary protein levels and water consumption. Corni Fructus also reduced serum total cholesterol, total triglyceride and low-density lipoprotein cholesterol levels, and showed a tendency of enhancing high-density lipoprotein cholesterol level. Levels of serum albumin and creatinine in diabetic rats were also significantly reduced by Corni Fructus administration at a dose of 200 and 400 mg/kg body mass compared with non-treated diabetic rats. Corni Fructus increased catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidose (GSH-px) activities in the kidneys of diabetic rats. Furthermore, Corni Fructus treatment enhanced renal peroxisome proliferator-activated receptor-γ (PPARγ) expression in diabetic rats. Conclusion: These results demonstrated that Corni Fructus may have the potential to protect the animals from diabetic nephropathy by amelioration of oxidative stress and stimulation of PPARγ expression.

Hypoglycemic effect of Gynostemma pentaphyllum saponins by enhancing the Nrf2 signaling pathway in STZ-inducing diabetic rats

Dawei Gao,Min Zhao,Ximing Qi,Yanping Liu,Nan Li,Zhiwei Liu,Yanhong Bian 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.2

Gynostemma pentaphyllum (GP) is a natural plant resources for diabetes therapy, however, there is little research on the mechanisms of GP. The present study was undertaken to characterize if G. pentaphyllum saponins (GPs) is the principal active compound of GP responsible for anti-diabetes, and to examine the relativity between blood glucose modulate and antioxidation. The GPs-treated streptozotocin diabetic rats had a more effective hypoglycemic status than those of diabetic control rats, which also ameliorate dyslipidemia. GPs has increased SOD and GSH-px activities, and the spleen and thymus indexes in diabetic rats. The insulin levels in the GPs-treated groups were significantly higher than diabetic control group. Our finding provides a new insight into the application of GPs for the treatment of oxidative stress related diseases.

Performance Evaluation and Analysis of Multiple Scenarios of Big Data Stream Computing on Storm Platform

( Dawei Sun ),( Hongbin Yan ),( Shang Gao ),( Zhangbing Zhou ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.7

In big data era, fresh data grows rapidly every day. More than 30,000 gigabytes of data are created every second and the rate is accelerating. Many organizations rely heavily on real time streaming, while big data stream computing helps them spot opportunities and risks from real time big data. Storm, one of the most common online stream computing platforms, has been used for big data stream computing, with response time ranging from milliseconds to sub-seconds. The performance of Storm plays a crucial role in different application scenarios, however, few studies were conducted to evaluate the performance of Storm. In this paper, we investigate the performance of Storm under different application scenarios. Our experimental results show that throughput and latency of Storm are greatly affected by the number of instances of each vertex in task topology, and the number of available resources in data center. The fault-tolerant mechanism of Storm works well in most big data stream computing environments. As a result, it is suggested that a dynamic topology, an elastic scheduling framework, and a memory based fault-tolerant mechanism are necessary for providing high throughput and low latency services on Storm platform.

Highly effective leakage magnetic field suppression by using a reactive coil in perfectly aligned EV wireless charging systems

Zhu, Guodong,Gao, Dawei The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

Using a reactive coil to suppress the leakage magnetic field (LMF) in wireless power transfer is practical, but the suppression capability reported in the literature is still limited. This paper proposes several methods for improving the suppression capability of this scheme. Three conditions are required to realize this goal, namely (1) a good LMF proportionality, (2) an equation regarding the LMF coefficients and mutual inductances, and (3) an equation regarding the impedance of the reactive coil loop. Coil geometry optimization is performed to meet condition (2), and coil reactance is compensated by a capacitor to meet condition (3). Given the trade-off between LMF suppression capability and efficiency, a control strategy based on a switching capacitor array is adopted. In the experiments, a 97.5% reduction in the LMF strength is achieved on the measurement point with slight effects on efficiency.

Leakage Magnetic Field Suppression Using Dual-Transmitter Topology in EV Wireless Charging

Guodong Zhu,Dawei Gao,Shulin Lin 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

This paper proposes an active leakage magnetic field (LMF) suppression scheme, which uses the dual-transmitter (DT) topology, for EV wireless charging systems (EVWCS). The two transmitter coils are coplanar, concentric and driven by separate inverters. The LMF components generated by the three coils cancel each other out to reduce the total field strength. This paper gives a detailed theoretical analysis on the operating principles of the proposed scheme. Finite element analysis is used to simulate the LMF distribution patterns. Experimental results show that when there is no coil misalignment, 97% of the LMF strength can be suppressed in a 1kW prototype. These results also show that the impact on efficiency is small. The trade-off between LMF suppression and efficiency is revealed, and a control strategy to balance these two objectives is presented.

Leakage Magnetic Field Suppression Using Dual-Transmitter Topology in EV Wireless Charging

Zhu, Guodong,Gao, Dawei,Lin, Shulin The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

This paper proposes an active leakage magnetic field (LMF) suppression scheme, which uses the dual-transmitter (DT) topology, for EV wireless charging systems (EVWCS). The two transmitter coils are coplanar, concentric and driven by separate inverters. The LMF components generated by the three coils cancel each other out to reduce the total field strength. This paper gives a detailed theoretical analysis on the operating principles of the proposed scheme. Finite element analysis is used to simulate the LMF distribution patterns. Experimental results show that when there is no coil misalignment, 97% of the LMF strength can be suppressed in a 1kW prototype. These results also show that the impact on efficiency is small. The trade-off between LMF suppression and efficiency is revealed, and a control strategy to balance these two objectives is presented.

Study of Spectral Reflectance Reconstruction Based on an Algorithm for Improved Orthogonal Matching Pursuit

Zhang Leihong,Liang Dong,Zhang Dawei,Gao Xiumin,Ma Xiuhua 한국광학회 2016 Current Optics and Photonics Vol.20 No.4

Spectral reflectance is sparse in space, and while the traditional spectral-reconstruction algorithm doesnot make full use of this characteristic sparseness, the compressive sensing algorithm can make full useof it. In this paper, on the basis of analyzing compressive sensing based on the orthogonal matching pursuitalgorithm, a new algorithm based on the Dice matching criterion is proposed. The Dice similarity coefficientis introduced, to calculate the correlation coefficient of the atoms and the residual error, and is used toselect the atoms from a library. The accuracy of Spectral reconstruction based on the pseudo-inversemethod, Wiener estimation method, OMP algorithm, and DOMP algorithm is compared by simulation onthe MATLAB platform and experimental testing. The result is that spectral-reconstruction accuracy basedon the DOMP algorithm is higher than for the other three methods. The root-mean-square error and colordifference decreases with an increasing number of principal components. The reconstruction error decreasesas the number of iterations increases. Spectral reconstruction based on the DOMP algorithm can improvethe accuracy of color-information replication effectively, and high-accuracy color-information reproductioncan be realized.

Model Predictive Torque Control of Surface Mounted Permanent Magnet Synchronous Motor Drives with Voltage Cost Functions

Zhang, Xiaoguang,Hou, Benshuai,He, Yikang,Gao, Dawei The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

In this paper, a model predictive torque control (MPTC) without the use of a weighting factor for surface mounted permanent-magnet synchronous machine (SPMSM) drive systems is presented. Firstly, the desired voltage vector is predicted in real time according to the principles of deadbeat torque and flux control. Then the sector of this desired voltage vector is determined. The complete enumeration for testing all of the feasible voltage vectors is avoided by testing only the candidate vectors contained in the sector. This means that only two voltage vectors in the sector need to be tested for selecting the optimal voltage vector in each control period. Thus, the calculation time can be reduced when compared with the conventional enumeration method. On the other hand, a novel cost function that only includes the dq-axis voltage errors between the desired voltage and candidate voltage is designed to eliminate the weighting factor used in the conventional MPTC. Thus, the control complexity caused by the tuning of the weighting factor is effectively decreased when compared with the conventional MPTC. Simulation and experimental investigation have been carried out to verify the proposed method.

Model Predictive Torque Control of Surface Mounted Permanent Magnet Synchronous Motor Drives with Voltage Cost Functions

Xiaoguang Zhang,Benshuai Hou,Yikang He,Dawei Gao 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

In this paper, a model predictive torque control (MPTC) without the use of a weighting factor for surface mounted permanentmagnet synchronous machine (SPMSM) drive systems is presented. Firstly, the desired voltage vector is predicted in real time according to the principles of deadbeat torque and flux control. Then the sector of this desired voltage vector is determined. The complete enumeration for testing all of the feasible voltage vectors is avoided by testing only the candidate vectors contained in the sector. This means that only two voltage vectors in the sector need to be tested for selecting the optimal voltage vector in each control period. Thus, the calculation time can be reduced when compared with the conventional enumeration method. On the other hand, a novel cost function that only includes the dq-axis voltage errors between the desired voltage and candidate voltage is designed to eliminate the weighting factor used in the conventional MPTC. Thus, the control complexity caused by the tuning of the weighting factor is effectively decreased when compared with the conventional MPTC. Simulation and experimental investigation have been carried out to verify the proposed method.