Expanding the Diversity of Allosteric Bcr-Abl Inhibitors

Deng, Xianming,Okram, Barun,Ding, Qiang,Zhang, Jianming,Choi, Yongmun,Adriá,n, Francisco J.,Wojciechowski, Amy,Zhang, Guobao,Che, Jianwei,Bursulaya, Badry,Cowan-Jacob, Sandra W.,Rummel, Gabriele American Chemical Society 2010 Journal of medicinal chemistry Vol.53 No.19

<P/><P>Inhibition of Bcr-Abl kinase activity by imatinib for the treatment of chronic myeloid leukemia (CML) currently serves as the paradigm for targeting dominant oncogenes with small molecules. We recently reported the discovery of GNF-2 (<B>1</B>) and GNF-5 (<B>2</B>) as selective non-ATP competitive inhibitors of cellular Bcr-Abl kinase activity that target the myristate binding site. Here, we used cell-based structure−activity relationships to guide the optimization and diversification of ligands that are capable of binding to the myristate binding site and rationalize the findings based upon an Abl−compound <B>1</B> cocrystal. We elucidate the structure−activity relationships required to obtain potent antiproliferative activity against Bcr-Abl transformed cells and report the discovery of new compounds (<B>5g</B>,<B> 5h</B>,<B> 6a</B>,<B> 14d</B>, and <B>21j-I)</B> that display improved potency or pharmacological properties. This work demonstrates that a variety of structures can effectively target the Bcr-Abl myristate binding site and provides new leads for developing drugs that can target this binding site.</P>

Sensorless control of printed permanent magnet synchronous motor

Xianming Deng,Maolin Li,Min Xu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.1

As a special disc motor, a printed permanent magnet synchronous motor (PMSM) uses a PCB printed board as the stator, which has the advantages of simple assembly, short axial distance, no stator slot, low eddy current loss, etc. Due to the stator-less core structure and the small number of winding turns, the inductance of the motor is very small. When vector control technology is used to drive the motor, the motor current pulse vibration is intense, there is a large number of integer multiples of the switching frequency high-frequency harmonics, there is also torque output pulse vibration, and it cannot be sampled to obtain the actual working state of the motor stator current, which affects the sliding mode sensorless control algorithm in terms of stator current estimation. Then it affects the motor speed and position estimation. In this paper, a solution involving high switching frequency control is proposed to obtain the characteristics of this kind of motor. In addition, the sensorless control of the motor based on the super-twisting sliding mode is realized. Simulation and experiments show the stability and effectiveness of the motor position free control system, and solve the problems related to severe motor stator current oscillation, motor output electromagnetic torque oscillation, and poor control performance of the sensorless algorithm caused by a small motor stator inductance.

Sensorless Control of Wound Rotor Synchronous Machines Based on High-frequency Signal Injection into the Stator Windings

Chen, Zhiguo,Deng, Xianming,Huang, Kun,Zhen, Wenhuan,Wang, Lei The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper proposes a sensorless control approach for Wound Rotor Synchronous Machines (WRSMs) based on a high frequency voltage signal injection into the stator side U phase and VW line, respectively. Considering the machine itself as a rotor position sensor, the rotor position observer is established according to the principles of the rotary transformer. A demodulation method for the high frequency signal inducted in the rotor is proposed as well. Simulation and experimental results show that the proposed sensorless control approach has high performance and good practicability.

Sensorless Control of Wound Rotor Synchronous Machines Based on High-frequency Signal Injection into the Stator Windings

Zhiguo Chen,Xianming Deng,Kun Huang,Wenhuan Zhen,Lei Wang 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper proposes a sensorless control approach for Wound Rotor Synchronous Machines (WRSMs) based on a high frequency voltage signal injection into the stator side U phase and VW line, respectively. Considering the machine itself as a rotor position sensor, the rotor position observer is established according to the principles of the rotary transformer. A demodulation method for the high frequency signal inducted in the rotor is proposed as well. Simulation and experimental results show that the proposed sensorless control approach has high performance and good practicability.

Simplified PWM Strategy for Neutral-Point-Clamped (NPC) Three-Level Converter

Ye, Zongbin,Xu, Yiming,Li, Fei,Deng, Xianming,Zhang, Yuanzheng The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.3

A novel simplified pulse width modulation(PWM) strategy for neutral point clamped (NPC) three-level converter is proposed in this paper.The direct output voltage modulation is applied to reduce the calculation time. Based on this strategy, several optimized control methods are proposed. The neutral point potential balancing algorithm is discussed and a fine neutral point potential balancing scheme is introduced. Moreover, the minimum pulse width compensation and switching losses reduction can be easily achieved using this modulation strategy. This strategy also gains good results even with the unequal DC link capacitor. The modulation principle is studied in detail and the validity of this simplified PWM strategy is experimentally verified in this paper. The experiment results indicated that the proposed PWM strategy has excellent performance, and the neutral point potential can be balanced well with unequal DC link captaincies.

Simplified PWM Strategy for Neutral-Point-Clamped (NPC) Three-Level Converter

Zongbin Ye,Yiming Xu,Fei Li,Xianming Deng,Yuanzheng Zhang 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.3

A novel simplified pulse width modulation(PWM) strategy for neutral point clamped (NPC) three-level converter is proposed in this paper.The direct output voltage modulation is applied to reduce the calculation time. Based on this strategy, several optimized control methods are proposed. The neutral point potential balancing algorithm is discussed and a fine neutral point potential balancing scheme is introduced. Moreover, the minimum pulse width compensation and switching losses reduction can be easily achieved using this modulation strategy. This strategy also gains good results even with the unequal DC link capacitor. The modulation principle is studied in detail and the validity of this simplified PWM strategy is experimentally verified in this paper. The experiment results indicated that the proposed PWM strategy has excellent performance, and the neutral point potential can be balanced well with unequal DC link captaincies.

Synthesis of Needle-Like Aragonite Crystals in the Presence of Magnesium Chloride and Their Application in Papermaking

Hu, Zeshan,Shao, Minghao,Li, Huayang,Cai, Qiang,Zhong, Chenghua,Xianming, Zhang,Deng, Yulin The Korean Society for Composite Materials 2009 Advanced composite materials Vol.18 No.4

PCC (precipitated calcium carbonate) and ground calcium carbonate have been widely used in alkaline papermaking. Unfortunately, although increasing filler level in papers can improve the paper properties such as brightness, opacity, stiffness gloss, smoothness, porosity, and printability, as well as decrease cost, some strength of the paper is negatively affected. In this research, needle-like aragonite was synthesized using $Ca(OH)_2$ and $CO_2$ as reactants in the presence of $MgCl_2$ and characterized with scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The physical and optical properties of the paper handsheets containing these needle-like aragonite fillers were evaluated. Results indicated that tensile strength, Z-direction tensile strength and folding endurance of the paper were improved by the needle-like aragonite crystals compared to the paper using commercial PCC (precipitated calcium carbonate) as filler. The stiffness of the paper handsheet on the machine direction was increased, but no evident difference in the cross direction was found. The improvement of paper strength mainly resulted from the twining effect between the aragonite whiskers and paper fibers. The optical properties of the paper were slightly decreased with the use of the needle-like aragonites compared to commercial PCC. These results suggest that paper cost can be decreased by increasing the content of needle-like aragonite filler while paper strength will not be decreased compared to PCC filler.