Extracellular signal-regulated kinase 5 increases radioresistance of lung cancer cells by enhancing the DNA damage response

Weiwei Jiang,Guanghui Jin,Fangfang Cai,Xiao Chen,Nini Cao,Xiangyu Zhang,Jia Liu,Fei Chen,Feng Wang,Wei Dong,Hongqin Zhuang,Zichun Hua 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Radiotherapy is a frequent mode of cancer treatment, although the development of radioresistance limits its effectiveness. Extensive investigations indicate the diversity of the mechanisms underlying radioresistance. Here, we aimed to explore the effects of extracellular signal-regulated kinase 5 (ERK5) on lung cancer radioresistance and the associated mechanisms. Our data showed that ERK5 is activated during solid lung cancer development, and ectopic expression of ERK5 promoted cell proliferation and G2/M cell cycle transition. In addition, we found that ERK5 is a potential regulator of radiosensitivity in lung cancer cells. Mechanistic investigations revealed that ERK5 could trigger IR-induced activation of Chk1, which has been implicated in DNA repair and cell cycle arrest in response to DNA double-strand breaks (DSBs). Subsequently, ERK5 knockdown or pharmacological inhibition selectively inhibited colony formation of lung cancer cells and enhanced IR-induced G2/M arrest and apoptosis. In vivo, ERK5 knockdown strongly radiosensitized A549 and LLC tumor xenografts to inhibition, with a higher apoptotic response and reduced tumor neovascularization. Taken together, our data indicate that ERK5 is a novel potential target for the treatment of lung cancer, and its expression might be used as a biomarker to predict radiosensitivity in NSCLC patients.

Applying a Forced Censoring Technique with Accelerated Modeling for Improving Estimation of Extremely Small Percentiles of Strengths

Weiwei Chen,Ramon V. Leon,Timothy M. Young,Frank M. Guess 한국신뢰성학회 2006 International Journal of Reliability and Applicati Vol.7 No.1

Optimal Allocation Method of Hybrid Active Power Filters in Active Distribution Networks Based on Differential Evolution Algorithm

Chen, Yougen,Chen, Weiwei,Yang, Renli,Li, Zhiyong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Chen, Xuling,Chen, Lu,Ye, Weiwei,Zhang, Weipeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediate coils is an effective means of improving transmission characteristics, including output power and transmission efficiency, when the transmission distance is increased. However, the position of intermediate coils in practice influences system performance significantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatial position of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalent circuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and the spatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases of transmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relatively stable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototype of the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoretical analysis.

Applying a Forced Censoring Technique with Accelerated Modeling for Improving Estimation of Extremely Small Percentiles of Strengths

Chen Weiwei,Leon Ramon V.,Young Timothy M.,Guess Frank M. The Korean Reliability Society 2006 International Journal of Reliability and Applicati Vol.7 No.1

Many real world cases in material failure analysis do not follow perfectly the normal distribution. Forcing of the normality assumption may lead to inaccurate predictions and poor product quality. We examine the failure process of the internal bond (IB or tensile strength) of medium density fiberboard (MDF). We propose a forced censoring technique that closer fits the lower tails of strength distributions and better estimates extremely smaller percentiles, which may be valuable to continuous quality improvement initiatives. Further analyses are performed to build an accelerated common-shaped Weibull model for different product types using the $JMP^{(R)}$ Survival and Reliability platform. In this paper, a forced censoring technique is implemented for the first time as a software module, using $JMP^{(R)}$ Scripting Language (JSL) to expedite data processing, which is crucial for real-time manufacturing settings. Also, we use JSL to automate the task of fitting an accelerated Weibull model and testing model homogeneity in the shape parameter. Finally, a package script is written to readily provide field engineers customized reporting for model visualization, parameter estimation, and percentile forecasting. Our approach may be more accurate for product conformance evaluation, plus help reduce the cost of destructive testing and data management due to reduced frequency of testing. It may also be valuable for preventing field failure and improved product safety even when destructive testing is not reduced by yielding higher precision intervals at the same confidence level.

Application of the French Codes to the Pressurized Thermal Shocks Assessment

Mingya Chen,Guian Qian,Jinhua Shi,Rongshan Wang,Weiwei Yu,Feng Lu,Guodong Zhang,Fei Xue,Zhilin Chen 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.6

The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs)has been extensively studied. This paper introduces an integrity assessment of an RPVsubjected to a PTS transient based on the French codes. In the USA, the “screening criterion”for maximum allowable embrittlement of RPV material is developed based on theprobabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, whichare developed based on the deterministic fracture mechanics, there is no “screening criterion”. In this paper, the methodology in the RCC-M and RSE-M codes, which are used forPTS analysis, are firstly discussed. The bases of the French codes are compared with ASMEand FAVOR codes. A case study is also presented. The results show that the method in theRCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF)may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significantdifferences in the assessment results. Therefore, homogenization of the codes inthe long time operation of nuclear power plants is needed.

Optimal Allocation Method of Hybrid Active Power Filters in Active Distribution Networks Based on Differential Evolution Algorithm

Yougen Chen,Weiwei Chen,Renli Yang,Zhiyong Li 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/ forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Xuling Chen,Lu Chen,Weiwei Ye,Weipeng Zhang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediatecoils is an effective means of improving transmission characteristics, including output power and transmission efficiency, whenthe transmission distance is increased. However, the position of intermediate coils in practice influences system performancesignificantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatialposition of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalentcircuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and thespatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases oftransmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relativelystable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototypeof the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoreticalanalysis.

Failure Mechanisms and Modes of Tunnels in Monoclinic and Soft-Hard Interbedded Rocks: A Case Study

Jianxun Chen,Weiwei Liu,Lijun Chen,Yanbin Luo,Yao Li,Haijiang Gao,Daochuan Zhong 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

The issue of large deformation mechanism in soft rock tunnels has puzzled tunnel scholars for decades. Previous studies have not evolved a clear and common understanding. Therefore, detailed on-site measurement, full investigation and statistical analysis have been conducted on the instability and failure of Muzhailing Tunnel since its construction, whose length is beyond 15 km. The study aims at systematically analyzing the failure mechanisms and modes of Muzhailing Tunnel in monoclinic and soft-hard interbedded rock strata. Study results show that the angle between strata strike and tunnel axis greatly determines the magnitude of deformation, the dip direction significantly controls the bias direction and maximum deformation direction, and the dip angle deeply affects the deformation form. The failure modes of surrounding rock mainly include four types: spalling and overturning failure, bending failure, shear slip failure and buckling failure. Large deformation characteristics are summarized from six aspects: failure form, groundwater, sensitivity to influencing factors, deformation degree, deformation speed and deformation duration. The instability modes of primary lining include in-plane (transverse) instability and out-plane (longitudinal) instability. Finally, the causes of large deformation are analyzed from geological, structural, engineering and human factors.

Development and Application of High-Performance Grouting Materials for Anchoring Pipe in Soft Rock Tunnel

Li-xin Zhang,Jianxun Chen,Lijun Chen,Yanbin Luo,Weiwei Liu,Fangfang Dong,Hao Chen,Hao-yang Zhu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

A high-performance grouting material is proposed to enhance the support effect of anchoring pipes in soft rock mass tunnels in this paper. Through mix proportion and strength tests, the initial setting time, compressive strength, and flowability of the grouting material were determined. Furthermore, based on grouting and pulling tests, the recommended parameters of the anchoringpipe were proposed. The results show that pure cement paste is an ideal grouting material for on-site application, demonstrating excellent anchoring, fluidity, high strength, and rapid hardening. Under optimal conditions of water-cement ratio at 0.46 and retarder proportion at 0.4‰, the initial settling time and the compressive strength of the grouting material are approximately 45 minutes and 28.5 MPa within 4 hours, respectively. The anchoring force of an anchoring pipe with a length of 6 m and a diameter of 76 mm can reach 448.9 kN within the same period. A field test involving anchoring pipes and pure cement paste was conducted during tunnel construction, resulting in a substantial reduction of maximum settlement and convergence of the tunnel by 57.53% and 40.48%, respectively. These results demonstrate the effectiveness