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Sema3A secreted by sensory nerve induces bone formation under mechanical loads 被引量:1
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作者 Hongxiang Mei Zhengzheng li +11 位作者 Qinyi Lv xingjian li Yumeng Wu Qingchen Feng Zhishen Jiang Yimei Zhou Yule Zheng Ziqi Gao Jiawei Zhou Chen Jiang Shishu Huang Juan li 《International Journal of Oral Science》 SCIE CAS CSCD 2024年第1期62-72,共11页
Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling. Here, we focused on the role of Semaphorin 3A(Sema3A), expressed by sensory nerves, in mechanical loads-induced bo... Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling. Here, we focused on the role of Semaphorin 3A(Sema3A), expressed by sensory nerves, in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM) model. Firstly, bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold. Sema3A, rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM. Moreover, in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs) within 24 hours.Furthermore, exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload. Mechanistically, Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway, maintaining mitochondrial dynamics as mitochondrial fusion. Therefore, Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation, both as a pain-sensitive analgesic and a positive regulator for bone formation. 展开更多
关键词 SEMA3A FORMATION OVERLOAD
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类聚氨基酸大分子的制备及其减水分散性能
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作者 蒋春源 陈元丰 +4 位作者 马建峰 李兴建 徐守芳 李法强 李因文 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第8期11-18,共8页
聚羧酸减水剂因为具有掺量低、减水率高及绿色环保等优点备受青睐,但实际应用中却因受到混凝土骨料中泥含量的影响,也常伴有相容性差、减水率低及坍落度损失大等问题。因此,文中从聚合物分子结构设计入手,采用异戊烯醇聚氧乙烯醚(TPEG)... 聚羧酸减水剂因为具有掺量低、减水率高及绿色环保等优点备受青睐,但实际应用中却因受到混凝土骨料中泥含量的影响,也常伴有相容性差、减水率低及坍落度损失大等问题。因此,文中从聚合物分子结构设计入手,采用异戊烯醇聚氧乙烯醚(TPEG)与甲基丙烯酸缩水甘油酯(GMA)进行共聚,再利用支链末端功能环氧基团与氨基乙酸(GA)反应制备了类聚氨基酸大分子(PAAs)。采用凝胶色谱和动态光散射对PAAs相对分子质量与其分布以及在水溶液中的聚集形态进行了表征,通过水泥净浆和混凝土实验对PAAs减水分散和抗泥敏感性能进行了研究。结果表明,PAAs在水溶液中以纳米聚集体的形式存在,粒径约30~120 nm,而正是由于PAAs聚集体的空间位阻效应在有效分散水泥颗粒的同时,还能显著阻止混凝土骨料中“泥”(蒙脱土)对PAAs的竞争插层吸附消耗,因而PAAs具有优异的减水分散和抗泥敏感性能,应用前景广阔。 展开更多
关键词 聚羧酸减水剂 类聚氨基酸大分子 自组装 减水分散 抗泥敏感
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基于点击化学反应高分散纳米二氧化硅改性聚氨酯的制备与性能 被引量:3
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作者 章强 鞠云鹏 +2 位作者 徐守芳 李兴建 张宜恒 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2020年第5期71-78,85,共9页
将4,4′-二羟甲基-1,4-庚二炔作为扩链剂制备了侧链含有端炔基的聚氨酯(PU),然后基于铜催化的1,3-偶极环加成点击化学反应,将含有高接枝密度3-叠氮基丙基三乙氧基硅烷的纳米二氧化硅和炔基功能化PU反应,制备了高分散纳米二氧化硅改性PU... 将4,4′-二羟甲基-1,4-庚二炔作为扩链剂制备了侧链含有端炔基的聚氨酯(PU),然后基于铜催化的1,3-偶极环加成点击化学反应,将含有高接枝密度3-叠氮基丙基三乙氧基硅烷的纳米二氧化硅和炔基功能化PU反应,制备了高分散纳米二氧化硅改性PU复合材料。对PU纳米复合材料的断面形貌、热稳定性和耐溶剂性进行了表征。研究结果表明,基于点击反应制备的纳米二氧化硅改性PU中的纳米粒子分散良好,热稳定性和耐溶剂性显著增强。随着纳米二氧化硅含量的增加,PU复合膜的耐溶剂性和热稳定性逐渐增强;与纯PU相比,纳米二氧化硅质量分数为3%时,PU膜的最大分解速度下的温度提高了12℃,甲苯吸附率降低了586%。 展开更多
关键词 铜催化 1 3-偶极环加成反应 聚氨酯 纳米二氧化硅
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可高温固化水性自分层含氟低表面能涂料及其涂膜性能 被引量:1
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作者 冷长松 李兴建 +3 位作者 唐朝钧 邓瑾妮 郑朝晖 丁小斌 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2020年第8期11-22,共12页
为获得一种性能优异的可高温固化自分层含氟低表面能涂料,采用阴离子乳液聚合法,分别合成了含活性基团的羟基丙烯酸乳液(E_1)和含氟羟基丙烯酸乳液(E_2),研究了乳化剂用量、引发剂用量和温度对2种聚合反应的影响。将E_1和E_2乳液复配成... 为获得一种性能优异的可高温固化自分层含氟低表面能涂料,采用阴离子乳液聚合法,分别合成了含活性基团的羟基丙烯酸乳液(E_1)和含氟羟基丙烯酸乳液(E_2),研究了乳化剂用量、引发剂用量和温度对2种聚合反应的影响。将E_1和E_2乳液复配成具有自分层效应的可高温固化含氟低表面能涂料,考察了活性官能团(-COOH,-OH)单体、含氟单体、涂料配比、初始温度、升温速率对涂膜性能的影响。结果表明,当丙烯酸(AA)单体和羟基丙烯酸(HEMA)单体分别占合成E_1和E_2单体总质量的4.5%和2.8%,2-(全氟辛基)乙基甲基丙烯酸酯(TEMAc-8)单体占合成E_2单体总质量的80%,引发剂用量分别占合成E_1和E_2单体总质量的0.5%和0.6%时,于80℃合成的乳液凝胶量少、粒径分布均匀、稳定性最好。当E_2乳液和固化剂分别占共混乳液质量的60%和6%,初始温度为80℃,以升温速率0.8℃/min,烘干到溶剂大量蒸发,然后于140℃高温条件下继续加热10 min时,所得涂膜分层效果及各项性能俱佳。 展开更多
关键词 自分层 高温固化 低表面能 涂料
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支化结构对形状记忆聚甲基丙烯酸酯-星形聚乙二醇半互穿网络性能的影响
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作者 李兴建 成俊杰 +3 位作者 薛申奥 徐守芳 郑朝晖 丁小斌 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2021年第11期62-68,76,共8页
半互穿聚合物网络(semi-IPNs)是设计形状记忆聚合物的一种模型网络结构。为了探究semi-IPNs中非交联网络组分的结构形态对形状记忆高分子性能的影响,文中设计制备了形状记忆聚甲基丙烯酸甲酯/星形聚乙二醇半互穿网络聚合物(PMMA/SPEGsem... 半互穿聚合物网络(semi-IPNs)是设计形状记忆聚合物的一种模型网络结构。为了探究semi-IPNs中非交联网络组分的结构形态对形状记忆高分子性能的影响,文中设计制备了形状记忆聚甲基丙烯酸甲酯/星形聚乙二醇半互穿网络聚合物(PMMA/SPEGsemi-IPNs),探究了SPEG分支长度对其力学强度、热性能、相分离程度、动态力学性能和形状记忆性能的影响,阐明了形状记忆PMMA/SPEGsemi-IPNs中SPEG的支化结构与形状记忆性能之间的关系。基于Edwards管道模型理论分析了SPEG支化结构对形状记忆PMMA/SPEGsemi-IPNs形状记忆性能的影响机制,采用蠕变测试对其理论分析进行了验证。研究结果表明,随着SPEG分支长度的增大,形状记忆PMMA/SPEGsemi-IPNs中的物理缠结作用增强,分子链松弛过程变慢,材料的玻璃化转变温度升高,模量增大,蠕变柔量增大,固定率降低,回复速度显著增大。 展开更多
关键词 形状记忆高分子 半互穿网络 星形聚乙二醇 支化结构
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A Novel Axial Flux Stator and Rotor Dual Permanent Magnet Machine 被引量:1
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作者 Yunchong Wang W.N.Fu xingjian li 《CES Transactions on Electrical Machines and Systems》 2017年第2期140-145,共6页
A novel structure of axial flux stator and rotor dual PMs Vernier machine is presented as an effective option for high torque-density direct-driven applications.The key is to locate PMs on both sides of rotor and stat... A novel structure of axial flux stator and rotor dual PMs Vernier machine is presented as an effective option for high torque-density direct-driven applications.The key is to locate PMs on both sides of rotor and stator.With dual PMs,this proposed machine with a novel structure generates an improved torque per armature current at low speed.It is very suitable for direct drive applications with limited space such as the in-wheel electric vehicle(EV)motors.The theory of the structure with PMs on both sides is analyzed theoretically.The structure and operation principle of machine are introduced and the steady and steady performance of machine is analyzed and verified with time-stepping finite element method(TS-FEM). 展开更多
关键词 DIRECT-DRIVE finite element method flux modulation high torque density permanent magnets
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The Chemical State of a Silver-Copper Complex Image Formed during the Electroless Copper Deposition
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作者 Yiheng Zhang xingjian li Zijiang Yang 《Natural Science》 2014年第11期852-858,共7页
By means of electroless copper deposition method a complex image has been fabricated in a mixture of cupric sulphate and formaldehyde, the surface and subsurface properties of which has been studied in detail by X-ray... By means of electroless copper deposition method a complex image has been fabricated in a mixture of cupric sulphate and formaldehyde, the surface and subsurface properties of which has been studied in detail by X-ray photoelectron spectroscopy (XPS) combined with sputter depth profiling technique analyzing distribution and chemical state of copper and silver. Depth profiling by XPS in conjunction with Ar+ sputtering shows that the catalytic activity of silver persists, catalyzing reduction of copper. The integral areas of spectra Ag3d after electroless copper deposition for 5 min at different sputtering times demonstrate that the amount of silver at the surface is greater than that in the interior. And then, the quite likely reasonable explanations are provided for the result. Additionally, the chemical shift of Ag3d XPS and deconvolution of Ag3d XPS spectrum have been also analyzed respectively at length. 展开更多
关键词 ELECTROCHEMISTRY ELECTROLESS Copper DEPOSITION Imaging AGENTS
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Chaperone-mediated Autophagy Regulates Cell Growth by Targeting SMAD3 in Glioma
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作者 Hanqun liu Yuxuan Yong +16 位作者 xingjian li Panghai Ye Kai Tao Guoyou Peng Mingshu Mo Wenyuan Guo Xiang Chen Yangfu Luo Yuwan lin Jiewen Qiu Ziling Zhang liuyan Ding Miaomiao Zhou Xinling Yang lin Lu Qian Yang Pingyi Xu 《Neuroscience Bulletin》 SCIE CAS CSCD 2022年第6期637-651,共15页
Previous studies suggest that the reduction of SMAD3(mothers against decapentaplegic homolog 3)has a great impact on tumor development,but its exact pathological function remains unclear.In this study,we found that th... Previous studies suggest that the reduction of SMAD3(mothers against decapentaplegic homolog 3)has a great impact on tumor development,but its exact pathological function remains unclear.In this study,we found that the protein level of SMAD3 was greatly reduced in human-grade IV glioblastoma tissues,in which LAMP2A(lysosome-associated membrane protein type 2A)was significantly up-regulated.LAMP2A is a key ratelimiting protein of chaperone-mediated autophagy(CMA),a lysosome pathway of protein degradation that is activated in glioma.We carefully analyzed the amino-acid sequence of SMAD3 and found that it contained a pentapeptide motif biochemically related to KFERQ,which has been proposed to be a targeting sequence for CMA.In vitro,we confirmed that SMAD3 was degraded in either serum-free or KFERQ motif deleted condition,which was regulated by LAMP2A and interacted with HSC70(heat shock cognate 71 kDa protein).Using isolated lysosomes,amino-acid residues 75 and 128 of SMAD3 were found to be of importance for this process,which affected the CMA pathway in which SMAD3 was involved.Similarly,down-regulating SMAD3 or up-regulating LAMP2A in cultured glioma cells enhanced their proliferation and invasion.Taken together,these results suggest that excessive activation of CMA regulates glioma cell growth by promoting the degradation of SMAD3.Therefore,targeting the SMAD3-LAMP2Amediated CMA-lysosome pathway may be a promising approach in anti-cancer therapy. 展开更多
关键词 Glioma-SMAD3 Chaperone-mediated autophagy Cell growth
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基于铜催化叠氮-炔环加成反应的聚氨酯功能化 被引量:1
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作者 章强 黄文峻 +2 位作者 王延斌 李兴建 张宜恒 《化学进展》 SCIE CAS CSCD 北大核心 2020年第2期147-161,共15页
聚氨酯(PU)作为一种重要的工业材料,具有诸多独特优异的性能,这使得PU材料在众多领域内具有极其广泛的应用。由于PU骨架上缺乏进一步修饰的功能基团,限制了PU材料的高附加值化,在高科技领域广泛应用受到阻碍。因此,PU的改性和功能化是... 聚氨酯(PU)作为一种重要的工业材料,具有诸多独特优异的性能,这使得PU材料在众多领域内具有极其广泛的应用。由于PU骨架上缺乏进一步修饰的功能基团,限制了PU材料的高附加值化,在高科技领域广泛应用受到阻碍。因此,PU的改性和功能化是学术界和工业界热门的课题之一。当前PU材料的改性和功能化方法较多,其中,叠氮化物与末端炔在铜(Ⅰ)催化下生成反式1,2,3-三唑化合物的Huisgen 1,3-偶极环加成(CuAAC)反应具有操作简单方便和灵活高效的特点,是点击化学反应的精髓,在PU材料的功能化改性研究中占有独特而重要的地位。本文简要介绍了基于CuAAC反应PU材料功能化改性的设计思路,重点综述了基于CuAAC反应,PU材料的生物相容性、疏水性、荧光性、抗菌性、阻燃性、形状记忆效应、机械性能和热稳定性的功能化改性研究和应用,最后总结了CuAAC反应在改性PU上存在的主要问题,并对其研究方向进行了展望。 展开更多
关键词 聚氨酯 点击化学 铜(Ⅰ)催化叠氮-炔环加成反应 功能化
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Late Mesozoic Tectonic Evolution of Southwestern Fujian Province,South China:Constraints from Magnetic Fabric,Zircon U-Pb Geochronology and Structural Deformation 被引量:5
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作者 Sen Wang Da Zhang +7 位作者 Ganguo Wu xingjian li Xiaoqiao Gao Absai Vatuva Yuan Yuan Tengda Yu Yu Bai Ye Fang 《Journal of Earth Science》 SCIE CAS CSCD 2018年第2期391-407,共17页
A combined study of magnetic fabrics, zircon U-Pb geochronology and structural deformation was carried out for Late Paleozoic sedimentary and Mesozoic magmatic rocks in the southwestern Fujian rift basin, South China,... A combined study of magnetic fabrics, zircon U-Pb geochronology and structural deformation was carried out for Late Paleozoic sedimentary and Mesozoic magmatic rocks in the southwestern Fujian rift basin, South China, aiming at deciphering the tectonic evolution during Late Mesozoic. Field observations showed that the Late Mesozoic structure deformations in southwestern Fujian were categorized into four phases: NW-SE compression, ENE-WSW extension, NNE-SSW compression and NNW-SSE extension, se- quentially. Zircons picked out from Juzhou granite and WNW-trending diabase dykes showed complete crys- tal shapes and clear oscillatory zonings on their edges, and the U-Pb dating yielded ages of 132 and 141 Ma, respectively. The susceptibility ellipsoid magnitude parameters of the Juzhou granite are characterized by flaser type strain ellipsoid, with pole density center of K3 falling into the first and the third quadrants, these fea- tures revealed that the Juzhou granite formed in ENE-WSW compressional stress field, indicating the early stage of Early Cretaceous extrusion in southwestern Fujian. The late stage of Early Cretaceous NNE-SSW ex- tension was limited by the widespread WNW-trending diabase dykes, which were usually regarded as impor- tant indications for a regional extensional setting. On the basic of the previous researches, structural deforma- tion studies, and the deductions above, it can be concluded that southwestern Fujian experienced five main tectonic stages during Late Mesozoic: Early Jurassic extension, Middie-Late Jurassic thrusting, early stage of Early Cretaceous extension, late stage of Early Cretaceous compression and Late Cretaceous extension. 展开更多
关键词 tectonic evolution magnetic fabric U-Pb dating structural deformation southwestern Fujian.
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A Novel Stator and Rotor Dual PM Flux Modulated Machine
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作者 Yunchong Wang W.N.Fu +1 位作者 Shuangxia Niu xingjian li 《Chinese Journal of Electrical Engineering》 CSCD 2017年第1期10-15,共6页
A novel structure of Veriner permanent magnet(VPM)machine is presented as an effective option for high torque density direct-driven applications.The key is to locate PMs on both sides of rotor and stator,and design th... A novel structure of Veriner permanent magnet(VPM)machine is presented as an effective option for high torque density direct-driven applications.The key is to locate PMs on both sides of rotor and stator,and design the stator PMs as a cylinder shape,the rotation of which can be controlled by an external driven system.With this design,magnetic field in the airgap can be directly regulated by the rotation of stator PMs.The structure and operation principle are introduced and the performance is analyzed with time-stepping finite element method(FEM).Analysis results show that the novel structure has really high torque density and good field weakening performance. 展开更多
关键词 Directly-driven finite element method flux modulation high torque density permanent magnets
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