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A novel micro-rolling&incremental sheet forming hybrid process:Deformation behavior and microstructure evolution

Chinese Journal of Aeronautics 2024年第5期37卷 603-622页

作者： Yanle LI feifei liu Hao YUAN Xiaoqiang LI Jianfeng LI Guoqun ZHAO Key Laboratory of High Efficiency and Clean Mechanical Manufacture Ministry of EducationShandong UniversityJi'nan 250061China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJi'nan 250061China

Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove arrays.An analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first established.Then,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are investigated.After the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat sheet.Meanwhile,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on average.After micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins increases.After incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more uniform.The present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.

关键词： Incremental sheet forming Microgrooves rolling Surface micromachining Groove size Microstructural evolution

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Identification of FOXO1 as a geroprotector in human synovium through single-nucleus transcriptomic profiling

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Protein & Cell 2024年第6期15卷 441-459页

作者： feifei liu Yi Lu Xuebao Wang Shuhui Sun Huize Pan Min Wang Zehua Wang Weiqi Zhang Shuai Ma Guoqiang Sun Qun Chu Si Wang Jing Qu Guang-Hui liu State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Sports Medicine Department Beijing Jishuitan HospitalCapital Medical UniversityBeijing 100035China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China Division of Life Sciences and Medicine School of Life SciencesUniversity of Science and Technology of ChinaHefei 230001China CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China The Fifth People’s Hospital of Chongqing Chongqing 400062China Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu Hospital Capital Medical UniversityBeijing 100053China Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijing 100053China

The synovium,a thin layer of tissue that is adjacent to the joints and secretes synovial fluid,undergoes changes in aging that contribute to intense shoulder pain and other joint diseases.However,the mechanism underlying human synovial aging remains poorly characterized.Here,we generated a comprehensive transcriptomic profile of synovial cells present in the subacromial synovium from young and aged individuals.By delineating aging-related transcriptomic changes across different cell types and their associated regulatory networks,we identified two subsets of mesenchymal stromal cells(MSCs)in human synovium,which are lining and sublining MSCs,and found that angiogenesis and fibrosis-associated genes were upregulated whereas genes associated with cell adhesion and cartilage development were downregulated in aged MSCs.Moreover,the specific cell-cell communications in aged synovium mirrors that of aging-related inflammation and tissue remodeling,including vascular hyperplasia and tissue fibrosis.In particular,we identified forkhead box O1(FOXO1)as one of the major regulons for aging differentially expressed genes(DEGs)in synovial MSCs,and validated its downregulation in both lining and sublining MSC populations of the aged synovium.In human FOXO1-depleted MSCs derived from human embryonic stem cells,we recapitulated the senescent phenotype observed in the subacromial synovium of aged donors.These data indicate an important role of FOXO1 in the regulation of human synovial aging.Overall,our study improves our understanding of synovial aging during joint degeneration,thereby informing the development of novel intervention strategies aimed at rejuvenating the aged joint.

关键词： FOXO1 degeneration inflammation

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Clinical features and risk factors for viral pneumonia complicated with invasive pulmonary aspergillosis in adult patients

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Chinese Medical Journal 2023年第11期136卷 1361-1363页

作者： Lijuan Li Chuan Wang Yali Ren Jiangbo liu feifei liu Xiaoqi Zhang Department of Pulmonary and Critical Care Medicine National Centre for Clinical Research on Respiratory DiseasesChina-Japan Friendship HospitalBeijing 100029China Department of Pulmonary and Critical Care Medicine First Hospital of ShijiazhuangShijiazhuangHebei 050011China Department of Pulmonary and Critical Care Medicine Second Hospital of Hebei Medical UniversityShijiazhuangHebei 050000China Department of Pulmonary and Critical Care Medicine Tianjin First Central HospitalTianjin 300192China Department of Respiratory and Critical Care Medicine First Hospital of Qin Huang DaoQinhuangdaoHebei 066000China Department of Pulmonary and Critical Care Medicine Second People’s Hospital of WeifangWeifangShandong 261041China

Viral pneumonia has recently been defined as a risk factor for invasive pulmonary aspergillosis(IPA).Wauters et al[1]reported that 23%of critically ill patients who were admitted to the intensive care unit(ICU)with swine-origin influenza A(H1N1)viral infection had developed invasive aspergillosis.IPA was diagnosed in 83 of 432(19%)patients who were admitted with influenza;for patients with influenza who were immunocompromised,the incidence of IPA reached up to 32%(38 of 117 patients).

关键词： patients admitted pneumonia

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Psoralen inhibits hepatitis B viral replication by down-regulating the host transcriptional machinery of viral promoters

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Virologica Sinica 2022年第2期37卷 256-265页

作者： Xinna Ma Heng Li Ying Gong feifei liu Xiankun Tong Fenghua Zhu Xiaoqian Yang Li Yang Jianping Zuo Laboratory of Immunology and Virology Shanghai University of Traditional Chinese MedicineShanghai201203China Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China

The hepatitis B virus(HBV) is a global public health challenge due to its highly contagious nature. It is estimated that almost 300 million people live with chronic HBV infection annually. Although nucleoside analogs markedly reduce the risk of liver disease progression, the analogs do not fully eradicate the virus. As such, new treatment options and drugs are urgently needed. Psoralen is a nourishing monomer of Chinese herb and is known to inhibit virus replication and inactivate viruses. In this study, we evaluated the potential of psoralen as an anti-HBV agent.Quantitative PCR and Southern blot analysis revealed that psoralen inhibited HBV replication in Hep G2.2.15 cells in a concentration-dependent manner. Moreover, psoralen was also active against the 3TC/ETV-dual-resistant HBV mutant. Further investigations revealed that psoralen suppressed both HBV RNA transcription and core protein expression. The transcription factor FOXO1, a known target for PGC1α co-activation, binds to HBV precore/core promoter enhancer II region and activates HBV RNA transcription. Co-immunoprecipitation showed that psoralen suppressed the expression of FOXO1, thereby decreasing the binding of FOXO1 co-activator PGC1αto the HBV promoter. Overall, our results demonstrate that psoralen suppresses HBV RNA transcription by downregulating the expression of FOXO1 resulting in a reduction of HBV replication.

关键词： Psoralen Hepatitis B virus(HBV) Forkhead box-O1(FOXO1) PPARγco-activator 1α(PGC1α) Transcription

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Generation mechanism and control of high-frequency vibration for tracked vehicles

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International Journal of Mechanical System Dynamics 2023年第2期3卷 146-161页

作者： Pingxin Wang Xiaoting Rui feifei liu Guoping Wang Hailong Yu Bin He Junjie Gu Nanjing University of Science and Technology NanjingChina Nanjing Research Institute of Inner Mongolian North Heavy Industries Group Corp.Ltd NanjingChina

A crawler system provides much larger ground contact,leading to excellent terrain adaptability.Due to its structural characteristics,high‐frequency vibration proportional to the vehicle speed is generated during the driving process.This is a result of the polygon and rolling effects between the track and the wheels.A field test of a tracked vehicle is performed to monitor movement signals of the chassis and a rocker arm.Their corresponding power spectral density distributions confirm the correctness of the frequency‐calculation equation.Then,a novel elastic track tensioning device with a damper is designed as a cushion between the idler and the chassis.Depending on its geometry,the equivalent damping coefficient for a dynamic model is evaluated.Subsequently,the damping is altered in response to different operating conditions by a hybrid damping fuzzy semiactive control system.The controller accounts for both chassis and track vibration.Based on the transfer matrix method for multibody systems,a dynamical model of the track system is developed.Control performances are evaluated using two numerical simulations of obstacle crossing and off‐road driving operations.Results indicate that the proposed semiactive tensioner is substantially better than the conventional one.This paper provides a novel feasible scheme for vibration reduction of tracked vehicles.

关键词： crawler system polygon effect damper elastic track tensioning device hybrid damping fuzzy semiactive control

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Strontium doped electrospinning fiber membrane with antibacterial and osteogenic properties prepared by pulse electrochemical method

Engineered Regeneration

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Engineered Regeneration 2022年第4期3卷 339-351页

作者： Yonggang liu Bolin Zhang feifei liu Yani Qiu Wenbo Mu Liang Chen Chuang Ma Tingjun Ye Yingbo Wang College of Chemical Engineering Xinjiang Normal University102 Xinyi RoadUrumqi 830054PR China Department of Orthopaedics Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint DiseasesShanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University School of Medicine197 Ruijin 2nd RoadShanghai 200025PR China Department of Orthopedics Center The First Affiliated Hospital of Xinjiang Medical University393 Xinyi RoadUrumqi 830054PR China Department of Pharmaceutical Research Shanghai Medicilon Inc.No.585 Chuanda RoadPudong New AreaShanghai 201299PR China Chemistry and Chemical Engineering Changji UniversityChangji 831100PR China

The osteogenic differentiation and new bone formation are commonly delayed by bacterial infection of orthopedic implants,which is urgent to be resolved quickly in the clinic.The current paper prepared a strontium-doped elec-trospinning fiber membrane with antibacterial and osteogenic properties by pulse electrochemical method.Poly-lactic acid/hydroxyapatite(PLLA/HA)composite fiber substrate was fabricated by electrospinning technology,and strontium doped SrHA/Cu/Polypyrrole(PPy)composite coating was constructed with pulse electrodeposi-tion method on its surface.The strontium doping technique,degradation of Sr^(2+)and Cu^(2+),cellular compatibility,and the antibacterial activity of the fiber membrane were examined.The results revealed that the deposition of phosphorus and calcium on composite fiber was the highest,indicating good biological activity.The release of Sr^(2+)and Cu^(2+)was stable and gradual due to the modulation of PPy.The composite fiber presented excellent antibacterial performance and the antibacterial rate was close to 100%against Staphylococcus aureus and Es-cherichia coli.Furthermore,it is conducive to the adhesion,spread,and proliferation of vascular endothelial cells and osteoblasts,namely outstanding osteogenesis and angiogenesis abilities.In conclusion,the multifunctional PLLA/HA@SrHA/Cu/PPy composite fiber membrane with good antibacterial and osteogenic activity by electro-spinning technology and pulsed electrochemical deposition method provides an effective strategy for the poor bone healing of infected bone defects.

关键词： Electrospinning Pulse electrodeposition method Bone induction Antibacterial property

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Efficient generation of complex vectorial optical fields with metasurfaces

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Light(Science & Applications) 2021年第4期10卷 681-694页

作者： Dongyi Wang feifei liu Tong liu Shulin Sun Qiong He Lei Zhou State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghaiChina Shanghai Engineering Research Centre of Ultra-Precision Optical Manufaauring Green Photonics and Department of Optical Science and EngineeringFudan UniversityShanghaiChina Academy for Engineering and Technology Fudan UniversityShanghaiChina Collabo rative Innovation Centre of Advanced Microstructures NanjingChina

Vectorial optical fields(VOFs)exhibiting arbitrarily designed wavefronts and polarization distributions are highly desired in photonics.However,current methods to generate them either require complicated setups or exhibit limited functionalities,which is unfavorable for integration-optics applications.Here,we propose a generic approach to efficiently generate arbitrary VOFs based on metasurfaces exhibiting full-motrix yet inhomogeneous Jones-matrix distributions.We illustrate our strategy with analytical calculations on a model system and an experimental demonstration of a meta-device that can simultaneously deflect light and manipulate its polarization.Based on these benchmark results,we next experimentally demonstrate the generation of a far-field VOF exhibiting both a vortex wavefront and an inhomogeneous polarization distribution.Finally,we design/fabricate a meta-device and experimentally demonstrate that it can generate a complex near-field VOF-a cylindrically polarized surface plasmon wave possessing orbital angular momentum-with an efficiency of-34%.Our results establish an efficient and ultracompact platform for generating arbitrary predesigned VOFs in both the near-and far-fields,which may find many applications in optical manipulation and communications.

关键词： arbitrary inhomogeneous generating

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Nd Isotopic and Model Age Study of the Shandong Province, North China Craton: Implications for Correlation with South Korea

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Journal of Earth Science 2019年第5期30卷 938-951页

作者： feifei liu Yaoqi Zhou School of Geosciences China University of Petroleum Qingdao 266580 China Function Laboratory for Marine Mineral Resource Geology and Exploration National Laboratory for Marine Science and Technology Qingdao 266071 China

The geological units in Shandong Province, North China are important parts of the North China Craton and offer important insights into their crustal evolutionary history. This paper presents 611 sets of Nd isotopic data of Archean–Mesozoic rocks from Shandong including the Luxi, Jiaobei, and Sulu terranes, which provides important constraints for crustal growth and reactivation. Nd-depleted mantle model ages(TDM) of Archean rocks with positive εNd(t) values showed that ca. 2.9 and 2.8–2.7 Ga were the most important periods of crustal growth in the Jiaobei and Luxi terranes, respectively, while the period of ca. 2.6–2.5 Ga in the Jiaobei terrane likely indicates a coherent event of crustal growth and reworking. During the Proterozoic, multi-stage rifting and collisional orogenic events possibly led to the reworking of Archean crust in the source region. The Nd isotopic data of the Paleoproterozoic and Neoproterozoic rocks from Sulu indicated significant reworking of older crust with juvenile magmatic input. Crustal reactivation occurred during the Mesozoic. The younger TDM ages of the Mesozoic rocks with low negative εNd(t) values indicate that a juvenile crustal/mantle component was added to the ancient basement. The reactivation reflectes significant crust-mantle interaction via the mechanism of crustal subduction and mantle-derived magma underplating, or possibly asthenospheric upwelling. In addition, the crustal correlation between Shandong and Korea(including the Gyeonggi massif, Ogcheon belt, and Yeongnam massif) is established in this study. The TDM age distribution provides evidence favoring the affinity relationship between the Gyeonggi massif and Ogcheon belt of South Korea and the Jiaobei and Sulu terranes of Shandong, while the Yeongnam massif is more correlated with the South China Block.

关键词： Nd model age crustal growth crust reactivation Shandong geochemistry Korea

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Distribution of chlorpyrifos in rice paddy environment and its potential dietary risk

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Journal of Environmental Sciences 2015年第9期27卷 101-107页

作者： Yan Fu feifei liu Chenglin Zhao Ying Zhao Yihua liu Guonian Zhu Institute of Pesticide and Environmental Toxicology Zhejiang University Research Institute of Subtropical Forestry Chinese Academy of Forestry

Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9–3.8 days（field） and 2.8–10.3 days（laboratory）, respectively. The initial distribution of chlorpyrifos followed the increasing order of water 〈 straw 〈 soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit（MRL） with a harvest interval of 14 days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake（ADI = 0.01 mg/kg bw） due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure,intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose（ARf D = 0.1 mg/kg bw）. The estimated short-term intakes（ESTIs） were 0.78% and 0.25% of the ARf D for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers.

关键词： Chlorpyrifos Distribution Paddy environment Dietary risk assessment

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Targeting ERK,an Achilles' Heel of the MAPK pathway,in cancer therapy

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Acta Pharmaceutica Sinica B 2018年第4期8卷 552-562页

作者： feifei liu Xiaotong Yang Meiyu Geng Min Huang Division of Antitumor Pharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of Sciences

The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell proliferation, differentiation, survival and death. As the most frequently mutated signaling pathway in human cancer, targeting the MAPK pathway has long been considered a promising strategy for cancer therapy. Substantial efforts in the past decades have led to the clinical success of BRAF and MEK inhibitors. However, the clinical benefits of these inhibitors are compromised by the frequently occurring acquired resistance due to cancer heterogeneity and genomic instability. This review briefly introduces the key protein kinases involved in this pathway as well as their activation mechanisms. We also generalize the correlations between mutations of MAPK members and human cancers, followed by a summarization of progress made on the development of small molecule MAPK kinases inhibitors. In particular, this review highlights the potential advantages of ERK inhibitors in overcoming resistance to upstream targets and proposes that targeting ERK kinase may hold a promising prospect for cancer therapy.

关键词： Mitogen-activated protein kinases Extracellular signal-regu lated kinase ERK inhibitor ERK kinase Cancer therapy Drug resistance

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