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Inhibiting ceramide synthase 5 expression in microglia decreases neuroinflammation after spinal cord injury

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Neural Regeneration Research 2025年第10期20卷 2955-2968页

作者： Wei Zhang yubao Lu Ruoqi shen yingjie Wu Chenrui Liu Xingxing Fang Liangming Zhang bin Liu Limin Rong Department of Spine Surgery The Third Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina National Medical Products Administration(NMPA)Key Laboratory for Quality Research and Evaluation of Cell Products GuangzhouGuangdong ProvinceChina Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery GuangzhouGuangdong ProvinceChina Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery GuangzhouGuangdong ProvinceChina

Microglia,the resident monocyte of the central nervous system,play a crucial role in the response to spinal cord ***,the precise mechanism remains *** investigate the molecular mechanisms by which microglia regulate the neuroinflammatory response to spinal cord injury,we performed single-cell RNA sequencing dataset analysis,focusing on changes in microglial *** found that the MG1 subpopulation emerged in the acute/subacute phase of spinal cord injury and expressed genes related to cell pyroptosis,sphingomyelin metabolism,and neuroinflammation at high ***,we established a mouse model of contusive injury and performed intrathecal injection of siRNA and molecular inhibitors to validate the role of ceramide synthase 5 in the neuroinflammatory responses and pyroptosis after spinal cord ***,we established a PC12-bV2 cell co-culture system and found that ceramide synthase 5 and pyroptosis-associated proteins were highly expressed to induce the apoptosis of neuron *** ceramide synthase 5 expression in a mouse model of spinal cord injury effectively reduced ***,ceramide synthase 5-induced pyroptosis was dependent on activation of the NLRP3 signaling *** ceramide synthase 5 expression in microglia in vivo reduced neuronal apoptosis and promoted recovery of neurological ***2g7 formed a“bridge”between sphingolipid metabolism and ceramide synthase 5-mediated cell death by inhibiting the NLRP3 signaling ***,these findings suggest that inhibiting ceramide synthase 5 expression in microglia after spinal cord injury effectively suppressed microglial pyroptosis mediated by NLRP3,thereby exerting neuroprotective effects.

关键词： ceramide synthase 5 gasdermin D microglia neuroinflammation NLRP3 nuclear factor kappa b Pla2g7 pyroptosis sphingomyelin metabolism spinal cord injury

Composition and size dependent torsion fracture of metallic glasses

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Journal of Materials Science & Technology 2021年第23期82卷 153-160页

作者： J.Dong J.shen y.H.Sun H.b.Ke b.A.Sun W.H.Wang H.y.bai Institute of Physics Chinese Academy of SciencesBeijing100190PR China College of Materials Science and Opto Electronic Technology University of Chinese Academy of SciencesBeijing100049PR China Songshan Lake Materials Laboratory DongguanGuangdong523808PR China

The fracture of metallic glasses(MGs)of different compositions and sizes down to micrometers under torsion loading were systematically *** to the flat shear fracture along the circumferential plane as commonly supposed under torsion,we find that the torsion fracture of metallic glasses can deviate from flat shear plane,and the fracture angle is closely dependent on the composition and the size of MG *** a conversion method,we show that the torsion fracture of both millimeterand micrometer-sized MGs can be described by the ellipse fracture criterion as originally proposed for the tension *** deviation from the circumferential shear plane under torsion is further shown to intrinsically relate to the fracture toughness of *** tougher MG tends to have a smaller fracture angle with respect to the maximum shear plane,and vice versa,indicating a correlation between the fracture toughness and pressure/normal stress sensitivity in *** results provide new insights on the fracture mechanism and are helpful to design and control the deformation and fracture behavior of MGs under torsion loading.

关键词： Metallic glasses Torsion fracture Pressure sensitivity Fracture toughness

Nonlinear Analysis of Pile Foundation Jacket Platform

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China Ocean Engineering 1997年第1期12卷 21-28页

作者： Xu, b shen, ZH Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

In this paper, the nonlinear collapse of the bOHAI-8 pile foundation jacket platform has been analyzed. The ultimate load and collapse process of two computational models of the structure are given. One model is of fixed support whose length is eight times the pile leg diameter and the other considers the nonlinearity of the soil-pile interaction.

关键词： nonlinear analysis jacket platform ultimate load platform collapse

NUMERICAL SIMULATION OF MACRO-SEGREGATION IN STEEL INGOT DURING SOLIDIFICATION

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 288-294页

作者： C.W.Ma H.F.shen T.y.Huang b.C.Liu Department of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 China

A mathematical model coupling the momentum, energy and species conservation equa-tions was proposed to calculate the macro--segregation of Fe--C alloy ingot during solid-ification. The corresponding simulation software which concurrently solves the macro-scopic mass, momentum, energy and species conservation equations has been developedby applying the SIMPLE algorithm.The thermo--solutal convection in a NH_4 Cl--H_2O ingot is verified and the result showsgood agreement with that reported. Then macro--segregation in a steel ingot is simu-lated by using the developed program. The steel ingot is in a rectangular mold with ariser. The fluid flow is mainly induced by the temperature field and the solid fraction.The macro--segregation pattern is mainly affected by the thermo--induced convectionin the mushy zone. The negative segregation forms along the walls of the casting.The positive segregation forms at the top center of the casting into the riser. Thespecies concentration reaches the peak in the center of the ingot where solidificationends lastly.

关键词： macro-segregation thermo-solutal convection steel ingot numerical simulation

Heavy fermions in high magnetic fields

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Chinese Physics b 2019年第1期28卷 25-38页

作者： M Smidman b shen C y Guo L Jiao X Lu H Q yuan Center for Correlated Matter and Department of Physics Zhejiang UniversityHangzhou 310058China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Heavy fermion materials are prototypical strongly correlated electron systems, where the strong electron–electron interactions lead to a wide range of novel phenomena and emergent phases of matter. Due to the low energy scales, the relative strengths of the Ruderman–Kittel–Kasuya–yosida(RKKy) and Kondo interactions can often be readily tuned by non-thermal control parameters such as pressure, doping, or applied magnetic fields, which can give rise to quantum criticality and unconventional superconductivity. Here we provide a brief overview of research into heavy fermion materials in high magnetic fields, focussing on three main areas. Firstly we review the use of magnetic fields as a tuning parameter,and in particular the ability to realize different varieties of quantum critical behaviors. We then discuss the properties of heavy fermion superconductors in magnetic fields, where experiments in applied fields can reveal the nature of the order parameter, and induce new novel phenomena. Finally we report recent studies of topological Kondo systems, including topological Kondo insulators and Kondo–Weyl semimetals. Here experiments in magnetic fields can be used to probe the topologically non-trivial Fermi surface, as well as related field-induced phenomena such as the chiral anomaly and topological Hall effect.

关键词： heavy fermions high magnetic fields quantum phase transitions heavy fermion superconductivity topological Kondo systems

Microstructure and mechanical optimization of probeless friction stir spot welded joint of an Al-Li alloy

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Journal of Materials Science & Technology 2018年第10期34卷 1739-1746页

作者： Q. Chu W.y. Li X.W. yang J.J. shen A. Vairis W.y. Feng W.b. Wang State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Xi'an710072 China Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics Geesthacht 21502 Germany Mechanical Engineering Department TEl of Crete Heraklion Crete 71004 Greece China PSW Center Beijing 100024 China

In this work, a third generation AI-Li alloy has been successfully spot welded with probeless friction stir spot welding （P-FSSW）, which is a variant of conventional friction stir welding. The box-behnken exper-imental design in response surface methodology （RSM） was applied to optimize the P-FSSW parameters to attain maximum tensile/shear strength of the spot joints. Results show that an optimal failure load of 7.83 kN was obtained under a dwell time of 7.2 s, rotation speed of 950 rpm and plunge rate of 30 mm/rain. Sufficient dwell time is essential for heat conduction, material flow and expansion of the stir zone to form a sound joint. Two fracture modes were observed, which were significantly affected by hook defect. In addition to mechanical testing, electron backscattering diffraction （EbSD） and differential scanning calorimetry （DSC） were used for microstructure evolution and property analysis. The precipitation of GP zone and AI3Li as well as the ultrafine grains were responsible for the high microhardness in the stir zone.

关键词： Probeless friction stir spot welding Precipitation Mechanical property Fracture mechanism

Design and fabrication of 1-D semiconductor nanomaterials for high-performance photovoltaics

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Science bulletin 2016年第5期61卷 357-367页

作者： Ning Han Zaixing yang Lifan shen Hao Lin ying Wang Edwin y.b.Pun yunfa Chen Johnny C.Ho State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of SciencesBeijing 100190 China CAS Center for Excellence in Urban Atmospheric Environment Xiamen 361021 China Department of Physics and Materials Science City University of Hong Kong Hong Kong China State Key Laboratory of Millimeter Waves City University of Hong Kong Hong Kong China shenzhen Research Institute City University of Hong KongShenzhen 518057 China Department of Electronic Engineering City University of Hong Kong Hong Kong China

To date, the cost-effective utilization of solar energy by photovoltaics for large-scale deployment remains challenging. Further cost minimization and efficiency maximization, through reduction of material consumption, simplification of device fabrication as well as optimization of device structure and geometry, are required. The usage of 1D nanomaterials is attractive due to the outstanding light coupling effect, the ease of fabrication, and integration with one-dimensional(1-D) semiconductor materials. The light absorption efficiency can be enhanced significantly, and the corresponding light-toelectricity conversion efficiency can be as high as their bulk counterparts. Also, the amount of active materials used can be reduced. This review summarizes the recent development of 1-D nanomaterials for photovoltaic applications, including the anti-reflection, the light absorption,the minority diffusion, and the semiconductor junction properties. With solid progress and prospect shown in the past 10 years, 1-D semiconductor nanomaterials are attractive and promising for the realization of high-efficiency and low-cost solar cells.

关键词： One-dimensional nanomaterials Photovoltaics Solar cells Light absorption Minority diffusion length Semiconductor junction

Microstructures and mechanical properties of Ti3Al/Ni-based superalloy joints brazed with AuNi filler metal

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Journal of Materials Science & Technology 2019年第9期35卷 2070-2078页

作者： H.S. Ren H.P.Xiong W.M. Long b. Chen y.X. shen J. Pang Welding and Plastic Forming Division Beijing Institutes of Aeronautical MatericalBeijing 100095China State Key Laboratory of Advanced brazing Filler Metals and Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001 China Department of Material Science and Engineering Beihang UniversityBeijing 100191China

For the purpose of high-temperature service and the weight reduction in aviation engineering applications, the dissimilar joining of Ti3Al-based alloy to Ni-based superalloy (GH536) was conducted using Au-17.5Ni (wt%) brazing filler metal. The microstructure and chemical composition at the interfaces were investigated by scanning electron microscope, X-ray diffraction and transmission electron microscope. The diffusion behaviors of elements were analyzed as well. The results indicated that the Ti3Al/GH536 joint microstructure was characterized by multiple layer structures. Element Ni from Au-Ni filler metal reacted with Ti3Al base metal, leading to the formation of AlNi2Ti and NiTi compounds. Element Ni from Ti3Al base metal reacted with Ni and thus Ni3Nb phase was detected in the joint central area. Due to the dissolution of Ni-based superalloy,(Ni,Au) solid solution ((Ni,Au)ss) and Ni-rich phase were visible adjacent to the superalloy side. The average tensile strength of all the joints brazed at 1253 K for 5-20 min was above 356 MPa at room-temperature. In particular, the joints brazed at 1253 K/15 min presented the maximum tensile strength of434 MPa at room-temperature, and the strength of 314 MPa was maintained at 923 K. AlNi2Ti compound resulted in the highest hardness area and the fracture of the samples subjected to the tensile test mainly occurred in this zone.

关键词： Ti3Al-based alloy Ni-based superalloy brazing Microstructure Tensile strength

FAILURES AND THE LIFE OF FURNACE TUbES

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 419-425页

作者： F.Z.shen y.Ding D.M.Hou Z.P.Ning y.Lü T.b.Dong A.R.Tuohuti Nanjing University of Technology Nanjing 210009 ChinaNanjing University of Technology Nanjing 210009 ChinaLutianhua Group Incorporated Luzhou 646300 ChinaLutianhua Group Incorporated Luzhou 646300 ChinaLutianhua Group Incorporated Luzhou 646300 ChinaSouthwestern Tarim Exploration & Development Company Zepu 844804 ChinaSouthwestern Tarim Exploration & Development Company Zepu 844804 China

It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. by the test of creep crack growth, it is also acquired that under same mechanic parameter C* (t), the rate of creep crack growth in the HAZ is more than twice as fast as in parent metals. Two mechanisms (overheating and thermal shock) of failure occurred in an accident are presented. The stress of thermal shock is analyzed, in which the change of the elasticity modulus with the radius ET = /(r) is considered. based on it, the safety region of the thermal shock is obtained. Finally, two sets of curves for the safe life are suggested which can facilitate to estimate the remaining life of HK-40 or HP-Nb tubes by their creep rupture data.

关键词： failure thermal stock creep crack growth remaining life furnace tube