University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Population & Control theory. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Antagonizing STAT3 Dimerization with a Rhodium(III) Complex

Abstract: Kinetically inert metal complexes have arisen as promising alternatives to existing platinum and ruthenium chemotherapeutics. Reported herein, to our knowledge, is the first example of a substitutionally inert, Group 9 organometallic compound as a direct inhibitor of signal transducer and activator of transcription 3 (STAT3) dimerization. From a series of cyclometalated rhodium(III) and iridium(III) complexes, a rhodium(III) complex emerged as a potent inhibitor of STAT3 that targeted the SH2 domain and inhibited STAT3 phosphorylation and dimerization. Significantly, the complex exhibited potent anti-tumor activities in an in vivo mouse xenograft model of melanoma. This study demonstrates that rhodium complexes may be developed as effective STAT3 inhibitors with potent anti-tumor activity.

Adaptive On/Off Delay-Compensated Active Rectifiers for Wireless Power Transfer Systems

Abstract: An adaptive on/off delay-compensation technique is proposed to improve the performance of CMOS active rectifiers for wireless power transfer (WPT) systems. The effects of the on/off delays on the performance of the active rectifiers with either a parallel-resonant or a series-resonant circuit at the secondary coil are studied, which include power conversion efficiency (PCE), voltage conversion ratio (VCR) and output voltage ripple. By adding two feedback loops to the active diodes to generate the switched-offset currents for the comparators adaptively, both on- and off-delays are compensated for accurately against PVT variations and mismatches. As a design example, a fully integrated active rectifier for biomedical applications with a parallel-resonant secondary was fabricated in a standard 0.35 μm CMOS process. With an AC input that ranges from 1.8 to 3.6 V, the measured VCR is higher than 90% and the measured PCE is higher than 89.1% for a load resistor of $500\ \Omega$ . In particular, the PCE is increased by 9% compared to the active rectifier without using the proposed technique.

Design and Robust Repetitive Control of a New Parallel-Kinematic XY Piezostage for Micro/Nanomanipulation

Abstract: This paper presents mechanism and controller design procedures of a new piezoactuated flexure XY stage for micro-/nanomanipulation applications. The uniqueness of the proposed stage lies in that it possesses an integrated parallel, decoupled, and stacked kinematical structure, which owns such properties as identical dynamic behaviors in X and Y axes, decoupled input and output motion, single-input-single-output (SISO) control, high accuracy, and compact size. Finite element analysis (FEA) was conducted to predict static performance of the stage. An XY stage prototype was fabricated by wire electrical discharge machining (EDM) process from the alloy material Al7075. Based on the identified plant transfer function of the micropositioning system, an H∞ robust control combined with a repetitive control (RC) was adopted to compensate for the unmodeled piezoelectric nonlinearity. The necessity of using such a combined control is also investigated. Experimental results demonstrate that the H∞ plus RC scheme improves the tracking response by 67% and 28% compared to the stand-alone H∞ for 1-D and 2-D periodic positioning tasks, respectively. Thus, the results illustrate the effectiveness of the proposed mechanism design and control approach.