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Learning robust principal components from L1-norm maximization

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第12期13卷 901-908页

作者： Ding-cheng feng feng CHEN wen-li XU Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Department of Automation Tsinghua University Beijing 100084 China

Principal component analysis(PCA) is fundamental in many pattern recognition *** research has been performed to minimize the reconstruction error in L1-norm based reconstruction error minimization(L1-PCA-REM) since conventional L2-norm based PCA(L2-PCA) is sensitive to ***,the variance maximization formulation of PCA with L1-norm(L1-PCA-VM) has been proposed,where new greedy and nongreedy solutions are *** with the gradient ascent perspective for optimization,we show that the L1-PCA-VM formulation is problematic in learning principal components and that only a greedy solution can achieve robustness motivation,which are verified by experiments on synthetic and real-world datasets.

关键词： Principal component analysis(PCA) Outliers L1-norm,Greedy algorithms Non-greedy algorithms

Potential microRNA panel for the diagnosis and prediction of overall survival of hepatocellular carcinoma with hepatitis B virus infection

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World Journal of Gastrointestinal Oncology 2020年第4期12卷 383-393页

作者： Qi Zhang Hai-feng Xu wen-Yue Song Peng-Jun Zhang yong-Bo Song School of Life Science and Biopharmaceutics Shenyang Pharmaceutical UniversityShenyang 110016Liaoning ProvinceChina Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Interventional Therapy DepartmentPeking University Cancer Hospital and InstituteBeijing 100142China

BACKGROUND In hepatocellular carcinoma(HCC),abnormal expression of multiple micro RNAs(miRNAs)has been shown to be involved in the malignant biological behavior of liver *** vast majority of liver cancer cases in China are closely related to hepatitis B virus(HBV)infection,but there are few studies on the changes of miRNA expression in the progression from HBV infection to *** To explore the role of miRNAs in the progression of HBV infection to cirrhosis and even to liver *** We screened differentially expressed miRNAs in 40 HBV cirrhosis,40 normal and15 HCC tissues by using a Taq Man Low Density Array and real time quantitative polymerase chain *** evaluate the power of the selected miRNAs to predict disease,we calculated the area under the receiver-operating-characteristic *** overall survival of HBV cirrhosis patients was analyzed via KaplanMeier *** The levels of miR-375,miR-122 and miR-143 were significantly lower in HBV cirrhosis tissues,while miR-224 was significantly higher than in the controls(P<0.0001).The area under the curves of the receiver-operating-characteristic curve for the 4-miRNA panel was 0.991(95%CI:0.974-1).Patients with a lower expression level of miR-224 or higher expression levels of miR-375,miR-122 and miR-143 had longer overall *** four miRNAs(miR-375,miR-122,miR-143 and miR-224)may be helpful for early diagnosis of HBV infection,HBV cirrhosis,and prediction of its overall survival.

关键词： Hepatitis B virus infection Hepatocellular carcinoma MicroRNAs Cirrhosis Biomarker Tissue

Macroscopic Regulation of Hierarchical Nanostructures in Liquid-crystalline Block Copolymers towards Functional Materials

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Chinese Journal of Polymer Science 2021年第4期39卷 397-416,I0004页

作者： feng Cai Yu-Xuan Chen wen-Zhong Wang Hai-feng Yu Department of Materials Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of EngineeringPeking UniversityBeijing 100871China

The great potential of liquid-crystalline block copolymers(LCBCs)containing photoresponsive mesogens toward novel applications in photonics and nanotechnology has been attracting increasing attention,due to the combination of the inherent property of microphase separation of block copolymers and the hierarchically-assembled structures of liquid-crystalline polymers(LCPs).The periodically ordered nanostructures in bulk film of LCBCs can be acquired by supramolecular cooperative motion,derived from the interaction between liquid-crystalline elastic deformation and microphase separation,which are able to improve physical properties of polymer film toward advanced functional ***,various micro/nano-patterned structures have been fabricated via light manipulation of photoresponsive LCBCs with good reproducibility and mass *** to recent developments in synthesis and polymerization techniques,diverse azobenzene-containing LCBCs have been designed,resulting in the creation of a wide variety of novel *** review illustrates recent progresses in macroscopic regulation of hierarchical nanostructures in LCBCs towards functional *** existing challenges are also discussed,showing perspectives for future studies.

关键词： Liquid-crystalline block copolymers Microphase separation Hierarchical nanostructures Functional materials

Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

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Neural Regeneration Research 2025年第3期20卷 763-778页

作者： Minghuang Gao Xinyue Wang Shijie Su Weicheng feng Yaona Lai Kongli Huang Dandan Cao Qi Wang Science and Technology Innovation Center Guangzhou University of Chinese MedicineGuangzhouGuangdong ProvinceChina Institute of Clinical Pharmacology Guangzhou University of Chinese MedicineGuangzhouGuangdong ProvinceChina The Sixth Affiliated Hospital Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

关键词： central nervous system meningeal lymphatic vessels immunity myeloid cells lymphatic cells neurodegenerative disease

Spontaneous ignition of corrugated cardboard under dynamic high radiant flux

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Defence Technology（防务技术） 2024年第10期40卷 65-77页

作者： Liu Liu Yan Gu Hong Yang Xing Wang Yang Zhou Xiaogan Dai yong Han Shanggang wen Ming Li Congmei Lin Changgen feng Fei Tang Yushi wen Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621999China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026China Institute of Applied Physics and Computational Mathematics China Academy of Engineering PhysicsBeijing 100088China

Understanding the response of solid combustibles under high radiant fluxes is critical in predicting the thermal damage from extreme *** the more moderate radiant fluxes in conventional hydrocarbon fires,extreme events such as strong explosion,concentrated sunlight and directed energy can generate dynamic radiant fluxes at the MW/m^(2) level,creating a unique threat to *** study investigates the pyrolysis and spontaneous ignition behaviors of corrugated cardboard by using both experimental and numerical methods,under 10-cm dynamic high radiant fluxes ranging from 0.2 to 1.25 MW/m^(2) for 10 *** spontaneous ignition process at dynamic high radiant fluxes was recorded and *** ignition modes were found at the critical radiant flux of 0.4 MW/m^(2),namely hot-gas spontaneous ignition and hot-residue piloted *** latter is not the focus of this paper due to its extremely small probability of *** research reveals that the increase in flux intensity induces shorter delay times for both pyrolysis and ignition,lower ignition energy density,along with a corresponding rise in the critical mass flux and surface temperature at ignition *** simulation results are generally aligned with the experimental findings,despite some divergences may be attributed to model simplifications and parameter *** work contributes to a deeper insight into material behavior under extreme radiation,with valuable implications for fire safety and hazard assessment.

关键词： Extreme radiation Fire safety Corrugated cardboard Pyrolysis Ignition temperature

Remote ischemic preconditioning protects liver ischemia-reperfusion injury by regulating eNOS-NO pathway and liver microRNA expressions in fatty liver rats

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Hepatobiliary & Pancreatic Diseases International 2017年第4期16卷 387-394页

作者： Yun-Fei Duan yong An feng Zhu yong Jiang Department of Hepatobiliary Surgery The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China

BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed to investigate the roles of RIPC in liver I/R in fatty liver rats and the involvement of endothelial nitric oxide synthase-nitric oxide (eNOS-NO) pathway and microRNA expressions in this process. METHODS: A total of 32 fatty rats were randomly divided into the sham group, I/R group, RIPC group and RIPC+I/R group. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) were measured. Hematoxylin-eosin staining was used to observe histological changes of liver tissues, TUNEL to detect hepatocyte apoptosis, and immunohistochemistry assay to detect heat shock protein 70 (HSP70) expression. Western blotting was used to detect liver inducible NOS (iNOS) and eNOS protein levels and realtime quantitative polymerase chain reaction to detect miR-34a, miR-122 and miR-27b expressions. RESULTS: Compared with the sham and RIPC groups, serum ALT, AST and iNOS in liver tissue were significantly higher in other two groups, while serum NO and eNOS in liver tissue were lower, and varying degrees of edema, degeneration and inflammatory cell infiltration were found. Cell apoptosis number was slightly lower in the RIPC+I/R group than that in I/R group. Compared with the sham group, HSP70 expressions were significantly increased in other three groups (all P<0.05). Compared with the sham and RIPC groups, elevated miR-34a expressions were found in I/R and RIPC+I/R groups (P<0.05). MiR-122 and miR-27b were found significantly decreased in I/R and RIPC+I/R groups compared with the sham and RIPC groups (all P<0.05). CONCLUSION: RIPC can reduce fatty liver I/R injury by affecting the eNOS-NO pathway and liver microRNA expressions.

关键词： fatty liver ischemia-reperfusion remote ischemic preconditioning nitric oxide heat shock protein 70 endothelial nitric oxide synthase inducible nitric oxide synthase liver microRNA

Effect of C/N Concentration Fluctuation on Formation of Plasma Electrolytic Carbonitriding Coating on Q235

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Journal of Iron and Steel Research International 2012年第11期19卷 39-45页

作者： JIANG yong-feng BAO Ye-feng YANG Ke College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022JiangsuChina

The plasma electrolytic carbonitriding （PEC/N） on the Q235 steel was investigated in an aqueous solution containing monoethanolamine and KC1 in a very short period of time. The microdischarge characteristics of the volt- age/current on the Q235 were observed using real-time imaging during the PEC/N. The microstructure and element distribution of the carbonitriding layer were examined using scanning electron microscope （SEM） equipped with energy dispersive spectroscope （EDS）. The effect of microdischarge on roughness, thickness and microhardness was evalua- ted. The formation of the carbonitriding layer was discussed. Research shows that it is similar in the microstructure and properties between the plasma electrolytic carbonitriding and the traditional gas carbonitriding. The formation of the carbonitriding layer results from the carbon and nitrogen fluctuation in PEC/N process. The microhardness and thickness can be up to HV 779 and 0. 360 mm in 180 s, respectively, which is close to the results of the gas carboni- triding in the microhardness. Therefore, the plasma electrolytic carbonit^riding has a potential to substitute the gas carbonitriding.

关键词： plasma electrolytic carbonitriding coating microstructure Q235

Creep rate sensitivities of materials by a depth-sensing indentation technique

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Journal of University of Science and Technology Beijing 2006年第4期13卷 308-312页

作者： Yang Gao Shengping wen feng Pan Laboratory of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

The strain rate sensitivity to creep of single crystal Cu（110）, metal tantalum, and 128°Y-X LiNbO3 piezoelectric single crystal were measured at room temperature by MTS Nanoindenter XP. Among the three kinds of materials studied, Cu showed the highest degree of resistance to creep-induced deformation, which is followed by Ta, while the LiNbO3 single crystal deformed more readily than the others. The values of the steady-state strain rate sensitivities determined by the indentation methods are in the range of 0.002-0.006, 0.02-0.06 and 0.02-0.03 for Cu, Ta, and LiNbO3, respectively. The mechanisms for the indentation-induced creeping behavior and the factors that influenced the creeping are discussed.

关键词： indentation creep strain rate sensitivity copper tantalum LiNbO3 piezoelectric single crystal

Application of microscopic transport model in the study of nuclear equation of state from heavy ion collisions at intermediate energies

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Frontiers of physics 2020年第4期15卷 133-151页

作者： yong-Jia Wang Qing-feng Li School of Science Huzhou UniversityHuzhou 313000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The equation of state(EOS)of nuclear matter,i.e.,the thermodynamic relationship between the binding energy per nucleon,temperature,density,as well as the isospin asymmetry,has been a hot topic in nuclear physics and astrophysics for a long *** knowledge of the nuclear EOS is essential for studying the propertics of muclei,the structure of neutron stars,the dynamics of heavy ion collision(HIC),as well as neutron star *** offers a unique way to create muclear matter with high density and isospin asymmetry in terrestrial laboratory,but the formed dense nuclear matter exists only for a very short period,one cannot measure the nuclear EOS directly in ***,transport models which often incorporate phenomenological potentials as an input are utilized to deduce the EOS from the comparison with the observables mcasured in *** ultrarelativistic quantum molecular dynamics(UrQMD)model has been widely employed for investigating HIC from the Fermi energy(40 MeV per nucleon)up to the CERN Large Hadron Collider energies(TeV).With further improvement in the nmuclear mean-field potential term,the collision term,and the cluster recognition term of the UrQMD model,the newly measured collective flow and nuclear stopping data of light charged particles by the FOPI Collaboration can be *** this article we highlight our recent results on the studies of the muclear EOS and the muclear symmetry energy with the UrQMD *** opportunities and challenges in the extraction of the nuclear EOS from transport models and HIC experiments are discussed.

关键词： muclear equation of state symmetry energy heavy ion collision transport model