检索结果-南通市图书馆

Macrophage-derived small extracellular vesicles promote biomimetic mineralized collagen-mediated endogenous bone regeneration

引用

International Journal of Oral Science 2020年第4期12卷 317-326页

作者： Anqi Liu Shanshan Jin Cuicui fu shengji Cui Ting Zhang Lisha Zhu Yu Wang steve g.f.shen Nan Jiang Yan Liu Department of Oral and Maxillofacial Surgery Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai Key Laboratory of StomatologyShanghaiChina Laboratory of Biomimetic Nanomaterials Department of OrthodonticsPeking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijingChina Department of Oral Biochemistry Academic Centre for Dentistry Amsterdam(ACTA)University of Amsterdam(UvA)and Vrije Universiteit Amsterdam(VU)Gustav Mahlerlaan 3004AmsterdamThe Netherlands Shanghai University of Medicine and Health Sciences ShanghaiChina Central Laboratory Peking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijingChina

Macrophages play an important role in material-related immune responses and bone formation,but the functionality of macrophage-derived extracellular vesicles(EVs)in material-mediated bone regeneration is still ***,we evaluated intracellular communication through small extracellular vesicles(sEVs)and its effects on endogenous bone regeneration mediated by biomimetic intrafibrillarly mineralized collagen(IMC).After implantation in the bone defect area,IMC generated more neobone and recruited more mesenchymal stem cells(MSCs)than did extrafibrillarly mineralized collagen(EMC).More CD63+CD90+and CD63+CD163+cells were detected in the defect area in the IMC group than in the EMC *** determine the functional roles of sEVs,extracellular vesicles from macrophages cultured on different mineralized collagen were isolated,and they showed no morphological ***,macrophage-derived sEVs in the IMC group showed an enhanced Young’s modulus and exerted beneficial effects on the osteogenic differentiation of bone marrow MSCs by increasing the expression of the osteoblastic differentiation markers BMP2,BgLAP,COL1,and OSX and calcium nodule ***,sEVs from IMC-treated macrophages facilitated MSC osteogenesis through the BMP2/Smad5 pathway,and blocking sEV secretion with gW4869 significantly impaired MSC proliferative,immunomodulative and osteogenic *** together,these findings show that macrophage-derived sEVs may serve as an emerging functional tool in biomaterial-mediated endogenous bone regeneration.

关键词： endogenous CD63 mediated

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Overexpression of Dlx2 enhances osteogenic differentiation of BMSCs and MC3T3-E1 cells via direct upregulation of Osteocalcin and Alp

引用

International Journal of Oral Science 2019年第2期11卷 119-130页

作者： Jianfei Zhang Wenbin Zhang Jiewen Dai Xudong Wang steve guofang shen Department of Oral & Cranio-maxillofacial Surgery Shanghai Ninth People’s Hospital Shanghai Jiao Tong University School of Medicine Shanghai Key Laboratory of Stomatology

genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation,and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the craniofacial *** aim of this study was to investigate the role and the underlying molecular mechanisms of Dlx2 in osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and pre-osteoblast MC3T3-E1 ***,we observed upregulation of Dlx2 during the early osteogenesis in BMSCs and MC3T3-E1 ***,Dlx2 overexpression enhanced alkaline phosphatase (ALP) activity and extracellular matrix mineralization in BMSCs and MC3T3-E1 cell *** addition,micro-CT of implanted tissues in nude mice confirmed that Dlx2 overexpression in BMSCs promoted bone formation in ***,Dlx2 overexpression had little impact on the expression level of the pivotal osteogenic transcription factors Runx2,Dlx5,Msx2,and Osterix,but led to upregulation of Alp and Osteocalcin (OCN),both of which play critical roles in promoting osteoblast ***,luciferase analysis showed that Dlx2 overexpression stimulated both OCN and Alp promoter *** chromatin-immunoprecipitation assay and site-directed mutagenesis analysis,we provide molecular evidence that Dlx2 transactivates OCN and Alp expression by directly binding to the Dlx2-response cis-acting elements in the promoter of the two *** on these findings,we demonstrate that Dlx2 overexpression enhances osteogenic differentiation in vitro and accelerates bone formation in vivo via direct upregulation of the OCN and Alp gene,suggesting that Dlx2 plays a crucial role in osteogenic differentiation and bone formation.

关键词： BMSCs MC3T3-E1 Osteocalcin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

grain refinement mechanism of Mg-3Sn-1Mn-1La alloy during accumulative hot rolling

引用

Journal of Materials Science & Technology 2021年第32期91卷 251-261页

作者： Z.Y.Zhao R.g.guan Y.f.shen P.K.Bai School of Materials Science and Engineering North University of ChinaTaiyuan 030051China bEngineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian 116028China Key Laboratory for Anisotropy and Texture of Materials Northeastern UniversityShenyang 110004China

We elucidate the effect of lanthanum(La) on the grain refinement of Mg-3 Sn-1 Mn alloy during accumulative hot rolling. The lath-shaped Mg_(2) Sn phase in the Mg-3 Sn-1 Mn alloy is firstly broken and spheroidized,and then the size increases and coarsens with the increase of rolling reduction, most of Mg_(2) Sn move from grain boundary to grain and are homogeneously distributed within the matrix. However, the plate-shaped Mg Sn La compound in Mg-3 Sn-1 Mn-1 La gradually becomes fine, spheroidized, and homogeneously distributed. The grain sizes of Mg-3 Sn-1 Mn and Mg-3 Sn-1 Mn-1 La alloys become fine through dynamic recrystallization(DRX), though the grain refinement of Mg-3 Sn-1 Mn-1 La alloy is better compared to the Mg-3 Sn-1 Mn alloy. A large number of uniformly distributed spherical Mg Sn La compounds pin the dislocations, thus increasing the dislocation density. Hence, the driving force for DRX increases and promotes the formation of deformation bands and more twins, providing the sites for DRX nucleation and growth.

关键词： Mg alloy grain refinement Dynamic recrystallization Accumulative hot rolling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Model for Liquid-Diffusion Catalytically grown fibrous Carbon Material

引用

Journal of Materials Science & Technology 1999年第1期15卷 1-4页

作者： Zhang, Wg Cheng, HM Su, g fan, YY Li, f shen, ZH Zhou, BL Chinese Acad Sci Met Res Inst Shenyang 110015 Peoples R China

A mechanism for the catalytically growth of vapor grown fibrous carbon (VgfC) preparing from the floating catalyst method has been proposed, in which liquid diffusion-determined diffusion of carbon atoms through catalyst particles is described mathematically, and the physical and chemical properties of the catalyst particles during the growth process are taken into account. from the model the growth rate and grown length of VgfC are calculated theoretically which coincides with the experimental data; and the necessity of reducing gas such as hydrogen in preparing VgfC is explained as to reduce fe3C, which acts as intermediate catalyst shown by the model. fe3C formed on the surface of gamma-fe will stop the growth of carbon fiber if they can not be reduced at once. Additionally, the growth temperature and diameter of VgfC are also discussed in the paper.

关键词： Li Cs A Model for Liquid-Diffusion Catalytically grown fibrous Carbon Material

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Probiotic metabolites from Bacillus coagulans ganedenBC30^(TM) support maturation of antigen-presenting cells in vitro

引用

World Journal of gastroenterology 2012年第16期18卷 1875-1883页

作者： Kathleen f Benson Kimberlee A Redman steve g Carter David Keller Sean farmer John R Endres gitte S Jensen NIS Labs 1437 EsplanadeKlamath FallsOR 97601United States ganeden Biotech 5915 Landerbrook DriveMayfield HeightsOH 44124United States AIBMR Life Sciences 4117 S MeridianPuyallupWA 98373United States

AIM:To study the effects of probiotic metabolites on maturation stage of antigen-presenting immune ***:ganeden Bacillus coagulans 30(gBC30) bacterial cultures in log phase were used to isolate the secreted metabolite(MET) fraction.A second fraction was made to generate a crude cell-wall-enriched fraction,by centrifugation and lysis,followed by washing.A preparation of MET was subjected to size exclusion centrifugation,generating three fractions:f human peripheral blood mononuclear cell(PBMC) as a source of antigen-presenting mononuclear *** maturation status of mononuclear phagocytes was evaluated by staining with monoclonal antibodies towards CD14,CD16,CD80 and CD86 and analyzed by flow ***:Treatment of PBMC with MET supported maturation of mononuclear phagocytes toward both macrophage and dendritic cell *** biological activity unique to the metabolites included a reduction of CD14+ CD16+ pro-inflammatory cells,and this property was associated with the high molecular weight metabolite *** were also seen for the dendritic cell maturation markers CD80 and *** CD14dim cells,an increase in both CD80 and CD86 expression was seen,in contrast to a selective increase in CD86 expression on CD14bright *** co-expression of CD80 and CD86 indicates effective antigen presentation to T cells and support of T helper cell *** selective expression of CD86 in the absence of CD80 points to a role in generating T regulatory ***:The data show that a primary mechanism of action of gBC30 metabolites involves support of more mature phenotypes of antigen-presenting cells,important for immunological decision-making.

关键词： Mononuclear phagocytes Dendritic cell maturation Co-stimulatory molecules Antigen-presentation Probiotics Metabolites

来源：

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

SYNTHESIS AND MICROSTRUCTURE Of SUPERHARD TiN/SiN_x MULTILAYER THIN fILMS

引用

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 242-248页

作者： Z.f.Zhou Y.g.shen Y.W.Mai K.Y.Li AdvancedCoatingsAppliedResearchLaboratory（ACARL） DepartmentofManufacturingEngineeringandEngineeringManagementCityUniversityofHongKongKowloonHongKongChina CentreforAdvancedMaterialsTechnology（CAMT） SchoolofAerospaceMechanicalandElectronicEngineeringUniversityofSydneySydneyNSW2006Australia

Multilayer thin films of TiN/SiNx have been deposited onto heated Si 100 substra tes (200℃) by reactive dc-magnetron sputtering from Ti and Si targets in an Ar- N2 gas mixture. The rotation speed of the substrate holder was varied from 1 to 20rpm, while target currents were held constant, to produce bilayer periods vary ing from approximately 22 to 0.6nm. These multilayer films were characterized by atomic force microscopy (AfM), cross-sectional transmission electron microscopy (TEM), scanning electron microscopy (SEM), and microhardness measurements. TEM and SEM studies showed elimination of columnar structure in TiN, owing to the in corporation of amorphous SiNx layers. The crystallinity of TiN and amorphous nat ure of SiNx were confirmed by high resolution TEM. An optimum rotation speed was observed, at which hardness was a maximum. The resulting bilayer period was fou nd to be approximately 1.6nm, which resulted in a significant improvement in mic rohardness (~57gPa). The rms surface roughness for this film was less than 1.5nm .

关键词： multilayers hardness supermodulu s stress TiN/SiNx

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ACTIVATION MECHANISM Of AMORPHOUS Ni_(63)Zr_(32)La_5 ALLOY HYDROgENATION CATALYST

引用

Acta Metallurgica Sinica(English Letters) 1996年第4期9卷 291-297页

作者： Wang, X.K. shen, N.f. Lei, g.J. gu, H.C.

The catalytic activity of amorphous Ni_63 Zr_32 La_5 ribbon for hydrogenation of ethyne to ethylene can be greatly enhanced when the alloy ribbon is pretreated with dilute acid solution,heated under negative atmosphere pressure and subjected to hydrogen reduction successively. The change of surface state of the ribbon during the activation has been analysed by AES and XPS. The surface of as-received ribbon is covered with a thin film of La_2 O_3. After pretreatment. the surface concentrations of both Ni and Zr increase obviously, whereas the surface concentration of La decreases ***, on the surface of activated catalyst the Ni and NiO disperse finely on the matrix consisting of oxides of both Zr and La and a small amount of fluorides of Zr and La.

关键词： amorphous Ni_(63) Zr_(32) La_5 alloy catalyst activation mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects

引用

Chinese Science Bulletin 2014年第4期59卷 349-355页

作者： Heqing shen f.L.Martin Yanhua Su Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences Centre for Biophotonics Lancaster Environment CentreLancaster University Department of Preventive Medicine School of Public Health of Xiamen University

In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ‘‘accessibility hypothesis' '. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference(RNAi) and other func- tional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic- modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations.

关键词：环境化学基因修饰压力源表观毒理效应评估 DNA甲基化相互作用

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SYNTHESIS AND THERMAL STABILITY Of NANOCOMPOSITE nc-TiN/a-TiB_2 THIN fILMS

引用

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 307-312页

作者： Y.H.Lu Z.f.Zhou P.Sit Y.g.shen K.Y.Li H.Chen DepartmentofPhysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina／／DepartmentofManufacturingEngineeringg~EngineeringManagementCityUniversityofHongKongKowloonHongKongChina DepartmentofManufacturingEngineering＆EngineeringManagement CityUniversityofHongKongKowloonHongKongChina DepartmentofPhysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina

Several nc-TiN/a-TiB2 thin films comprised of nanocrystalline (nc-) TiN and amor phous (a-) TiB2 phases were deposited on Si(100) at room temperature by reactive unbalanced dc magnetron sputtering, followed by vacuum annealed at 400, 600, 80 0 and 1000℃ for 1h, respectively. Effects of B content on microstructure, mecha nical behaviors and thermal microstructure stability have been investigated by X -ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and nanoindentation measurements. The results indicated that B addition greatly affected both microstructure and mechanical behavior of nc-Ti N/a-TiB2 thin films. With increasing B content the grain size decreased. A maxim um hardness value of about 33gPa was obtained at B content of about 19at.%. The improved mechanical properties of nc-TiN/a-TiB2 films with the addition of B int o TiN were attributed to their densified microstructure with development of fine grain size. Only addition of sufficient B could restrain grain growth during an nealing. High B content resulted in high microstructure stability. The crystalli zation of amorphous matrix occurred at about 800℃, forming TiB or TiB2 crystall ite, depending on B content. Before that no change in bonding configuration was found.

关键词： annealing boron reactive unbalanced dc magnetron sputtering ther mal stability nc-TiN/a-TiB2 thin film

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

COMPOSITION EffECT ON DRY SLIDINg WEAR BEHAVIORS Of Ti-B-N THIN fILMS

引用

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 300-306页

作者： P.Sit Y.H.Lu H.Chen Z.f.Zhou Y.g.shen K.Y.Li DepartmentofPhysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina DepartmentofPhysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina／／DepartmentofManufacturingEngineeringg：EngineeringManagementCityUniversityofHongKongKowloonHongKongChina DepartmentofManufacturingEngineering＆EngineeringManagement CityUniversityofHongKongKowloonHongKongChina

friction and sliding wear behaviour of Ti-B-N coatings against AISI440C steel ba ll and WC-6wt%Co ball were studied by using pin-on-disk tribometer along with mi crostructure characterization using optical microscopy (OM), scanning electron m icroscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is shown that the wear resistance of film depended on the wear mechanism. In the case of AISI440C steel, adhesive wear were pre-dominant and the wear rate increased sharply to a maximum when N content reach ~38at.%. This might be related to the change of fi lm microstructure and phase configuration, so the least adhesive transfer of tri bo-film was observed. If WC-6wt%Co ball was used, less deformation wear debris w as observed, this was responsible for the rise of wear rate. Despite of differen t wear modes, friction coefficients in both cases were found to depend mainly on the formation and the amount of h-BN phase. Elemental analysis by energy disper sive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) revealed that oxygen participated in the wear behavior by reacting with films to form the deb ris comprised of various types of Ti oxide including TiO, TiO2 and Ti2O3 , which increased wear resistance.

关键词： dry sliding wear friction coefficient oxidation Ti-B-N wear

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：