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Zhang Wentao,Zheng Zongtai,Wang Keyi,Mao Weipu,Li Xue,Wang Guangchun,Zhang Yuanyuan,Huang Jianhua,Zhang Ning,Wu Pengfei,Liu Ji,Zhang Haimin,Che Jianping,Peng Bo,Zheng Junhua,Li Wei,Yao Xudong 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-
Accumulating studies have confirmed that PIWI-interacting RNAs (piRNAs) are considered epigenetic effectors in cancer. We performed piRNA microarray expression analysis on renal cell carcinoma (RCC) tumor tissues and paired normal tissues and performed a series of in vivo and in vitro experiments to explore piRNAs associated with RCC progression and investigate their functional mechanisms. We found that piR-1742 was highly expressed in RCC tumors and that patients with high piR-1742 expression had a poor prognosis. Inhibition of piR-1742 significantly reduced tumor growth in RCC xenograft and organoid models. Mechanistically, piRNA-1742 regulates the stability of USP8 mRNA by binding directly to hnRNPU, which acts as a deubiquitinating enzyme that inhibits the ubiquitination of MUC12 and promotes the development of malignant RCC. Subsequently, nanotherapeutic systems loaded with piRNA-1742 inhibitors were found to effectively inhibit the metastasis and growth of RCC in vivo. Therefore, this study highlights the functional importance of piRNA-related ubiquitination in RCC and demonstrates the development of a related nanotherapeutic system, possibly contributing to the development of therapeutic approaches for RCC.
Terahertz Characteristics of Hydroxygraphene Based on Microfluidic Technology
Boyan Zhang,Siyu Qian,Bo Peng,Bo Su,Zhuang Peng,Hailin Cui,Shengbo Zhang,Cunlin Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.4
Hydroxygraphene as a kind of functionalized graphene has important applications in composite, photoelectric and biological materials. In the present study, THz and microfluidic technologies were implemented to study the THz transmission characteristics of hydroxygraphene with different concentrations and residence times in magnetic and electric fields. The results show that the THz transmission intensity decreases with the increase in sample concentration and duration of an applied electric field, while it increases by staying longer in the magnetic field. The phenomenon is analyzed and explained in terms of hydrogen bond, conductivity and scattering characteristics. The results establish a foundation for future research on the THz absorption characteristics of liquid graphene based on microfluidic technology in different external environments. It also provides technical support for the application and development of graphene in THz devices.
Peng Zhang,Vincent, Abhilash,Kumar, Amit,Seal, Sudipta,Hyoung Jin Cho IEEE 2010 IEEE electron device letters Vol.31 No.7
<P>The hydrogen-sensing performance of a nanosensor integrating interdigitated electrodes with a gap of 100 nm and indium-oxide-doped tin dioxide nanoparticles is investigated at room temperature. The nonlinear behavior observed from the I/V curves of the sensor in air atmosphere indicated the presence of a Schottky barrier contact at the electrode/sensing-material interface. The linear I/V response obtained in hydrogen atmosphere suggested that the Schottky barrier height could be modulated in the presence of hydrogen. At a low applied voltage of 0.4 V and 0.09-vol% hydrogen gas exposure, a very large sensitivity of 2300 and a short response time of 127 s were recorded.</P>
The Admissible Multiperiod Mean Variance Portfolio Selection Problem with Cardinality Constraints
Peng Zhang,Bing Li 대한산업공학회 2017 Industrial Engineeering & Management Systems Vol.16 No.1
Uncertain factors in finical markets make the prediction of future returns and risk of asset much difficult. In this paper, a model,assuming the admissible errors on expected returns and risks of assets, assisted in the multiperiod mean variance portfolio selection problem is built. The model considers transaction costs, upper bound on borrowing risk-free asset constraints, cardinality constraints and threshold constraints. Cardinality constraints limit the number of assets to be held in an efficient portfolio. At the same time, threshold constraints limit the amount of capital to be invested in each stock and prevent very small investments in any stock. Because of these limitations, the proposed model is a mix integer dynamic optimization problem with path dependence. The forward dynamic programming method is designed to obtain the optimal portfolio strategy. Finally, to evaluate the model, our result of a meaning example is compared to the terminal wealth under different constraints.
Peng Zhang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.8
Traditional Photovoltaic (PV) mathematical models have advantage of high accuracy, but its characteristics are multi-parameters and non-linear, which makes it difficult to be solved. Obviously, these are not suitable for engineering design since it requires both complexity and accuracy. In this paper, a simplified precision engineering PV mathematical model is proposed based on analysis of double diode PV cells mathematical model, and also gives a parameter calculation method based on Newton-Raphson method. Four different kinds of PV materials and variable resistance parameter characteristics are separately tested under different irradiance and temperature conditions. The results show that the proposed model can quickly and accurately reflect the PV model I-V and P-V characteristics, which has good versatility and sensitivity, and provides strong support for PV system related research.
Flexure-Hinges Guided Nano-Stage for Precision Manipulations: Design, Modeling and Control
Peng-Bo Liu,Peng Yan,Zhen Zhang,Tong-Tong Leng 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.
In this paper, a novel piezoelectric actuator driven nano-stage with bridge type mechanism is studied from the perspectives of design optimization, dynamical modeling, as well as controller synthesis for high precision manipulation purposes. FEM (Finite Element Method) analysis and dynamical modeling are provided to derive the system model including the hysteresis nonlinearity. Considering the complexities of dynamical uncertainties and hysteresis nonlinearity, an active disturbance rejection controller is developed consisting of extended state observer (ESO), state feedback controller and profile generator. With the proposed algorithm, the nonlinear dynamics, system uncertainties and external disturbances can be treated as part of the “total disturbances”, such that the extended state observer can be used to estimate and suppress the effects of these complex dynamics. The proposed control algorithm is deployed in real time implementations on the designed nano-stage, where experimental results demonstrate good control performance in terms of high precision positioning, hysteresis compensation and disturbance rejection.
Peng He,Shucai Li,Jie Xiao,Qian-qing Zhang,Fei Xu,Jian Zhang 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.5
Numerous studies on the instability and shear strength of expansive soil slopes have suggested that the fundamental reason forshallow sliding failures is insufficient shear strength caused by repeated dry-wet cycles under low stress. Therefore, this paper studiedthe effects of low stress and dry-wet cycles on the shear strength of expansive soil slopes. A nonlinear curve that can be well fittedusing generalized power functions was observed for the shear strength of expansive soil, and a numerical model with nonlinearlydistributed shear strength taken into consideration was built using FISH. In this way, the dynamic distribution of shear strength as afunction of vertical stress was obtained. Compared to conventional models, the proposed model was more accurate in terms oftheoretical aspects, and the obtained results exhibited improved consistency with the actual mode. In order to improve theapplicability of this model, a mapping model of atmospheric action and engineering design of safety factors of slopes was establishedusing a Gaussian Process Regression (GPR) model, which is suitable for cases characterized by high dimension, small samplepopulation, and nonlinearity. Herein, the numerical calculations were replaced with output responses. In this way, fast prediction ofthe stability of expansive soil slopes in terms of a shallow sliding failure prediction model was achieved. To verify the feasibility ofthe proposed approach, dynamic predictions of shallow sliding failures of expansive soil slopes were carried out for NanyouHighway under different rainfall conditions. Meanwhile, safety factor responses corresponding to different slope design schemeswere also obtained using the proposed model, providing reference for slope stability analysis in expansive soil zones.