检索结果-南通市图书馆

Targeting RAF dimers in RAS mutant tumors:From biology to clinic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第5期14卷 1895-1923页

作者： Huanhuan Yin Qiulin Tang Hongwei xia Feng bi Division of Abdominal Cancer Department of Medical OncologyCancer Center and Laboratory of Molecular Targeted Therapy in OncologyWest China HospitalSichuan UniversityChengdu 610041China

RAS mutations occur in approximately 30%of tumors worldwide and have a poor prognosis due to limited *** targeting of KRAS G12C has achieved significant success in recent years,but there is still a lack of efficient therapeutic approaches for tumors with non-G12C KRAS mutations.A highly promising approach is to target the MAPK pathway downstream of RAS,with a particular focus on RAF ***-generation RAF inhibitors have been authorized to treat BRAF mutant tumors for over a ***,their use in RAS-mutated tumors is not recommended due to the paradoxical ERK activation mainly caused by RAF *** address the issue of RAF dimerization,type II RAF inhibitors have emerged as leading *** clinical studies have shown the initial effectiveness of these agents against RAS mutant ***,type II RAF inhibitors in combination with MEK or ERK inhibitors have demonstrated impressive efficacy in RAS mutant *** review aims to clarify the importance of RAF dimerization in cellular signaling and resistance to treatment in tumors with RAS mutations,as well as recent progress in therapeutic approaches to address the problem of RAF dimerization in RAS mutant tumors.

关键词： RAS mutations RAF dimerization RAF inhibitors Cancer therapy Drug resistance

An Efficient WRF Framework for Discovering Risk Genes and Abnormal Brain Regions in Parkinson's Disease Based on Imaging Genetics Data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2021年第2期36卷 361-374页

作者： xia-An bi Zhao-Xu Xing Rui-Hui Xu Xi Hu College of Information Science and Engineering Hunan Normal UniversityChangsha 410006China Hunan Provincial Key Laboratory of Intelligent Computing and Language Information Processing Hunan Normal UniversityChangsha 410006China

As an emerging research field of brain science,multimodal data fusion analysis has attracted broader attention in the study of complex brain diseases such as Parkinson's disease(PD).However,current studies primarily lie with detecting the association among different modal data and reducing data *** data mining method after fusion and the overall analysis framework are *** this study,we propose a weighted random forest(WRF)model as the feature screening *** interactions between genes and brain regions are detected as input multimodal fusion features by the correlation analysis *** implement sample classification and optimal feature selection based on WRF,and construct a multimodal analysis framework for exploring the pathogenic factors of *** experimental results in Parkinson's Progression Markers Initiative(PPMI)database show that WRF performs better compared with some advanced methods,and the brain regions and genes related to PD are *** fusion of multi-modal data can improve the classification of PD patients and detect the pathogenic factors more comprehensively,which provides a novel perspective for the diagnosis and research of *** also show the great potential of WRF to perform the multimodal data fusion analysis of other brain diseases.

关键词： multimodal fusion feature Parkinson's disease pathogenic factor detection sample classification weighted random forest model

Relativistic Filamentation of Intense Laser Beam in Inhomogeneous Plasma

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2012年第12期14卷 1054-1058页

作者： xia Xiongping YI lin Department of Physics Huazhong University of Science and Technology Wuhan 430074China Department of Science Guilin University of Technology Guilin 541004 China

In the paper, relativistic filamentation of intense laser beam in inhomogeneous plasma is investigated based on the nonparaxial region theory. The results show that, relativistic nonlinearity plays a main role in beam filamentation, and plasma inhomogeneity further reinforces the beam filamentation. The combination effects of relativistic nonlinearity and plasma inhomogeneity can generate particularly intense and short pulse laser. However, plasma inhomogeneity leads to obvious filamentation instability.

关键词： relativistic filamentation relativistic nonlinearity plasma inhomoheneous

A unified analysis of a micro-beam,droplet and CNT ring adhered on a substrate:Calculation of variation with movable boundaries

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2013年第1期29卷 62-72页

作者： Jian-lin Liu Re xia School of Pipeline and Civil Engineering China University of Petroleum School of Power and Mechanical Engineering Wuhan University

In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube （CNT） ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thor- oughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materi- als, and hold potential for enhancing their mechanical, chemical, optical and electronic properties.

关键词： Variational theory - Transversality condition Beam adhesion Droplet adhesion Carbon nanotube ring adhesion

Analysis of Thermoelastohydrodynamic Performance of Journal Misaligned Engine Main Bearings

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2015年第3期28卷 511-520页

作者： bi Fengrong SHAO Kang LIU Changwen WANG xia ZHANG Jian State Key Laboratory of Engines Tianjin University

To understand the engine main bearings＇ working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely considered simultaneously in most studies. A typical finite element model is selected and the effect of thermoelastohydrodynamic（TEHD） reaction on engine main bearings is investigated. The calculated method of main bearing＇s thermal hydrodynamic reaction and journal misalignment effect is finite difference method, and its deformation reaction is calculated by using finite element method. The oil film pressure is solved numerically with Reynolds boundary conditions when various bearing characteristics are calculated. The whole model considers a temperature-pressure-viscosity relationship for the lubricant, surface roughness effect, and also an angular misalignment between the journal and the bearing. Numerical simulations of operation of a typical I6 diesel engine main bearing is conducted and importance of several contributing factors in mixed lubrication is discussed. The performance characteristics of journal misaligned main bearings under elastohydrodynamic（EHD） and TEHD loads of an I6 diesel engine are received, and then the journal center orbit movement, minimum oil film thickness and maximum oil film pressure of main bearings are estimated over a wide range of engine operation. The model is verified through the comparison with other present models. The TEHD performance of engine main bearings with various effects under the influences of journal misalignment is revealed, this is helpful to understand EHD and TEHD effect of misaligned engine main bearings.

关键词： main bearings journal misaligned oil film pressure Reynolds equation finite difference methods thermoelastohydrodynamic(TEHD)

Molecular Dynamics Investigation of Differences in Melting Behaviors of Cu57 and Cu58 Clusters

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2009年第1期22卷 69-74页

作者： lin Zhang Hai-xia Sun Institute of Materials Physics and Chemistry College of Science Northeastern University Shenyang 110004 China

Within the framework of the embedded-atom method, we performed molecular-dynamics calculations to investigate the structural transformation during melting of two copper clus- ters containing 57 and 58 atoms. The simulation results reveal how their different structural changes can strongly influence internal energy and radial distribution functions. The local structural patterns of different regions during the temperature increase, determined by atom density profiles, are identified for the melting of each cluster. The simulations show sensi- tivities of the structural changes for these two small size clusters with different structures.

关键词： Molecular dynamics Cluster Surface Melting

Conductive and tribological properties of TiN-Ag composite coatings under grease lubrication

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2021年第4期9卷 774-788页

作者： Feihu lin Yanqiu xia Xin FENG School of Energy Power and Mechanical Engineering North China

TiN-Ag composite coatings were prepared by pulsed bias arc ion plating.X-ray diffraction(XRD)and energy dispersive X-ray spectroscopy(EDS)were applied to analyze the compositions of the *** properties of the coatings were studied using an MFT-R4000 ball-on-disk friction tester in the presence of lubricating greases containing multilayer *** electron microscopy(SEM),Raman spectroscopy,and X-ray photoelectron spectroscopy(XPS)were used to analyze the worn surface compositions of the lubricating *** results show that with the decrease in Ag in the film,hardness increased but electrical conductivity *** coating with 10 at%Ag content shows the best friction-reducing and anti-wear properties,which can be attributed to the moderate content of Ag embedded in the TiN crystal gap that enhanced the grain bonding force to improve the anti-wear and self-lubricating *** can be adsorbed on the coating as a solid lubricant.

关键词： silver tribology contact resistance lubricating grease

Diesel Engine Valve Clearance Fault Diagnosis Based on Features Extraction Techniques and FastICA-SVM

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2017年第4期30卷 991-1007页

作者： Ya-bing Jing Chang-Wen Liu Feng-Rong bi xiao-Yang bi xia Wang Kang Shao State Key Laboratory of Engines Tianjin UniversityTianjin 300072 China School of Mechanical Engineering Tianjin UniversityTianjin 300072 China Internal Combustion Engine Research Institute Tianjin University Tianjin 300072 China

Numerous vibration-based techniques are rarely used in diesel engines fault diagnosis in a direct way, due to the surface vibration signals of diesel engines with the complex non-stationary and nonlinear time-varying fea- tures. To investigate the fault diagnosis of diesel engines, fractal correlation dimension, wavelet energy and entropy as features reflecting the diesel engine fault fractal and energy characteristics are extracted from the decomposed signals through analyzing vibration acceleration signals derived from the cylinder head in seven different states of valve train. An intelligent fault detector FastICA-SVM is applied for diesel engine fault diagnosis and classification. The results demonstrate that FastlCA-SVM achieves higher classification accuracy and makes better general- ization performance in small samples recognition. Besides, the fractal correlation dimension and wavelet energy and entropy as the special features of diesel engine vibration signal are considered as input vectors of classifier FastlCA- SVM and could produce the excellent classification results. The proposed methodology improves the accuracy of fea- ture extraction and the fault diagnosis of diesel engines.

关键词： Feature extraction Diesel engine valve train FastlCA PCA Support vector machine

Reliability analysis of aero-engine blades considering nonlinear strength degeneration

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2013年第3期26卷 631-637页

作者： lin Jiewei Zhang Junhong Yang Shuo bi Fengrong State Key Laboratory of Engines Tianjin University

To comprehensively consider the effects of strength degeneration and failure correlation, an improved stress–strength interference （SSI） model is proposed to analyze the reliability of aeroengine blades with the fatigue failure mode. Two types of TC4 alloy experiments are conducted for the study on the damage accumulation law. All the parameters in the nonlinear damage model are obtained by the tension–compression fatigue tests, and the accuracy of the nonlinear damage model is verified by the damage tests. The strength degeneration model is put forward on the basis of the Chaboche nonlinear damage theory and the Griffith fracture criterion, and determined by measuring the fatigue toughness during the tests. From the comparison of two kinds of degeneration models based on the Miner’s linear law and the nonlinear damage model respectively, the nonlinear model has a significant advantage on prediction accuracy especially in the later period of life. A time-dependent SSI reliability model is established. By computing the stress distribution using the finite element （FE） technique, the reliability of a single blade during the whole service life is obtained. Considering the failure correlation of components, a modified reliability model of aero-engine blades with common cause failure （CCF） is presented. It shows a closer and more reasonable process with the actual working condition. The improved reliability model is illustrated to be applied to aero-engine blades well, and the approach purposed in this paper is suitable for any actual machinery component of aero-engine rotor systems.

关键词： Blade Fatigue Nonlinear strength degeneration Reliability Stress–strength interference