Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disrupti...Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.展开更多
The intervertebral disc(IVD) is the largest avascular tissue. Hypoxia-inducible factors(HIFs) play essential roles in regulating cellular adaptation in the IVD under physiological conditions. Disc degeneration disease...The intervertebral disc(IVD) is the largest avascular tissue. Hypoxia-inducible factors(HIFs) play essential roles in regulating cellular adaptation in the IVD under physiological conditions. Disc degeneration disease(DDD) is one of the leading causes of disability, and current therapies are ineffective. This study sought to explore the role of HIFs in DDD pathogenesis in mice. The findings of this study showed that among HIF family members, Hif1α was significantly upregulated in cartilaginous endplate(EP) and annulus fibrosus(AF) tissues from human DDD patients and two mouse models of DDD compared with controls. Conditional deletion of the E3 ubiquitin ligase Vhl in EP and AF tissues of adult mice resulted in upregulated Hif1α expression and age-dependent IVD degeneration. Aberrant Hif1α activation enhanced glycolytic metabolism and suppressed mitochondrial function. On the other hand, genetic ablation of the Hif1α gene delayed DDD pathogenesis in Vhl-deficient mice. Administration of 2-methoxyestradiol(2ME2), a selective Hif1α inhibitor, attenuated experimental IVD degeneration in mice. The findings of this study show that aberrant Hif1α activation in EP and AF tissues induces pathological changes in DDD, implying that inhibition of aberrant Hif1α activity is a potential therapeutic strategy for DDD.展开更多
Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further he...Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.展开更多
Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors ...Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors mechanism is classified into EDLCs （electrochemical double layer capacitors） and pseudocapacitors. Multidimensional carbon nanomaterials （active carbon, carbon nanotube, graphene, etc.）, carbon-based composite and corresponding electrolyte are the critical and important factor in the eyes of researcher. In this minireview, we will discuss the storage mechanism and summarize recent developed novel carbon and carbon-based materials in supercapacitors. The techniques to design the novel nanostructure and high performance electrodematerials that facilitate charge transfer to achieve high energy and power densities will also be discussed.展开更多
The transcription factor Sox9 was first discovered in patients with campomelic dysplasia,a haploinsufficiency disorder with skeletal deformities caused by dysregulation of Sox9 expression during chondrogenesis.Since t...The transcription factor Sox9 was first discovered in patients with campomelic dysplasia,a haploinsufficiency disorder with skeletal deformities caused by dysregulation of Sox9 expression during chondrogenesis.Since then,its role as a cell fate determiner during embryonic development has been well characterized;Sox9 expression differentiates cells derived from all three germ layers into a large variety of specialized tissues and organs.However,recent data has shown that ectoderm-and endoderm-derived tissues continue to express Sox9 in mature organs and stem cell pools,suggesting its role in cell maintenance and specification during adult life.The versatility of Sox9 may be explained by a combination of posttranscriptional modifications,binding partners,and the tissue type in which it is expressed.Considering its importance during both development and adult life,it follows that dysregulation of Sox9 has been implicated in various congenital and acquired diseases,including fibrosis and cancer.This review provides a summary of the various roles of Sox9 in cell fate specification,stem cell biology,and related human diseases.Ultimately,understanding the mechanisms that regulate Sox9 will be crucial for developing effective therapies to treat disease caused by stem cell dysregulation or even reverse organ damage.展开更多
Defects of articular cartilage present a unique clinical challenge due to its poor self-healing capacity and avascular nature.Current surgical treatment options do not ensure consistent regeneration of hyaline cartila...Defects of articular cartilage present a unique clinical challenge due to its poor self-healing capacity and avascular nature.Current surgical treatment options do not ensure consistent regeneration of hyaline cartilage in favor of fibrous tissue.Here,we review the current understanding of the most important biological regulators of chondrogenesis and their interactions,to provide insight into potential applications for cartilage tissue engineering.These include various signaling pathways,including fibroblast growth factors(FGFs),transforming growth factor b(TGF-b)/bone morphogenic proteins(BMPs),Wnt/b-catenin,Hedgehog,Notch,hypoxia,and angiogenic signaling pathways.Transcriptional and epigenetic regulation of chondrogenesis will also be discussed.Advances in our understanding of these signaling pathways have led to promising advances in cartilage regeneration and tissue engineering.展开更多
Tungsten carbide(WC)-based materials are widely considered as the hydrogen evolution reaction(HER)process catalysts due to their“Pt-like”electronic structure.Nonetheless,traditional powder electrodes have a high cos...Tungsten carbide(WC)-based materials are widely considered as the hydrogen evolution reaction(HER)process catalysts due to their“Pt-like”electronic structure.Nonetheless,traditional powder electrodes have a high cost,and display problems related to the process itself and the poor stability over operation time.This paper presented a self-supported asymmetric porous ceramic electrode with WO_(3-x)whiskers formed in situ on the walls of the finger-like holes and membrane surface,which was prepared by combining phase inversion tape-casting,pressureless sintering,and thermal treatment in a CO_(2) atmosphere.The optimized ceramic electrode displayed good catalytic HER activity and outstanding stability at high current densities.More specifically,it demonstrated the lowest overpotentials of 107 and 123 mV and the lowest Tafel slopes of 59.3 and 72.4 mV·dec^(-1)at 10 mA·cm^(-2)in acidic and alkaline media,respectively.This superior performance was ascribed to the structure of the ceramic membrane and the charge transfer efficiency,which was favored by the in situ developed WC/WO_(3-x)heterostructure and the oxygen vacancies.展开更多
Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herei...Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herein,a low-cost,eco-friendly,simple-operating,and time-saving technique,named electrical discharge,is reviewed in relation to developments from the nature of this technique in different dielectric media to the practical experience in controlling the main processing parameters,apparatuses,types of discharge,from the various structures and components to the wide applications.The development of the electrical discharge technique will play an important role in improving the technology to prepare superfine inorganic particles with high purity.Meanwhile,electrical discharge contributes to easily mixing solid materials from the atomic scale to several micrometers with different structures.Moreover,metal oxides or doping materials are accessible as the dielectric medium is changed.Considering some excellent advantages,new inorganic particles exploited through the electrical discharge method will promise to be the most rewarding in some potential applications.展开更多
文摘Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.
基金supported by grants from the National Key Research and Development Program of China (2018YFA0800802)the National Natural Science Foundation of China (81830075, 81772306, 81530071, and 81991513)the Chongqing Talent Plan (CQYC202001008 and CQYC202005088)
文摘The intervertebral disc(IVD) is the largest avascular tissue. Hypoxia-inducible factors(HIFs) play essential roles in regulating cellular adaptation in the IVD under physiological conditions. Disc degeneration disease(DDD) is one of the leading causes of disability, and current therapies are ineffective. This study sought to explore the role of HIFs in DDD pathogenesis in mice. The findings of this study showed that among HIF family members, Hif1α was significantly upregulated in cartilaginous endplate(EP) and annulus fibrosus(AF) tissues from human DDD patients and two mouse models of DDD compared with controls. Conditional deletion of the E3 ubiquitin ligase Vhl in EP and AF tissues of adult mice resulted in upregulated Hif1α expression and age-dependent IVD degeneration. Aberrant Hif1α activation enhanced glycolytic metabolism and suppressed mitochondrial function. On the other hand, genetic ablation of the Hif1α gene delayed DDD pathogenesis in Vhl-deficient mice. Administration of 2-methoxyestradiol(2ME2), a selective Hif1α inhibitor, attenuated experimental IVD degeneration in mice. The findings of this study show that aberrant Hif1α activation in EP and AF tissues induces pathological changes in DDD, implying that inhibition of aberrant Hif1α activity is a potential therapeutic strategy for DDD.
基金the National Natural Science Foundation of China(51772042,51802294 and 51972046)Sichuan Science and Technology Plan(2017JY0348,2018FZ0100)"111"Center(B13042)。
文摘Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.
基金Acknowledgment This work was financially supported by the National Natural Science Foundation of China （No. 51402040）, China Postdoctoral Science Foundation （2015M582539）, Science and Technology Support Program of Sichuan Province （2016RZ0054） and the National Hi-Tech Research and Development Program （863 Program） of China （No. 2015AA034202）.
文摘Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors mechanism is classified into EDLCs （electrochemical double layer capacitors） and pseudocapacitors. Multidimensional carbon nanomaterials （active carbon, carbon nanotube, graphene, etc.）, carbon-based composite and corresponding electrolyte are the critical and important factor in the eyes of researcher. In this minireview, we will discuss the storage mechanism and summarize recent developed novel carbon and carbon-based materials in supercapacitors. The techniques to design the novel nanostructure and high performance electrodematerials that facilitate charge transfer to achieve high energy and power densities will also be discussed.
基金supported in part by the research grant from the National Institutes of Health(AR50142 to RCH)supported in part by The University of Chicago Core Facility Subsidy grant from the National Center for Advancing Translational Sciences(NCATS)of the National Institutes of Health through Grant UL1 TR000430.SD was a recipient of The University of Chicago Pritzker Fellowship and AOA Carolyn L.Kuckein Fellowship.
文摘The transcription factor Sox9 was first discovered in patients with campomelic dysplasia,a haploinsufficiency disorder with skeletal deformities caused by dysregulation of Sox9 expression during chondrogenesis.Since then,its role as a cell fate determiner during embryonic development has been well characterized;Sox9 expression differentiates cells derived from all three germ layers into a large variety of specialized tissues and organs.However,recent data has shown that ectoderm-and endoderm-derived tissues continue to express Sox9 in mature organs and stem cell pools,suggesting its role in cell maintenance and specification during adult life.The versatility of Sox9 may be explained by a combination of posttranscriptional modifications,binding partners,and the tissue type in which it is expressed.Considering its importance during both development and adult life,it follows that dysregulation of Sox9 has been implicated in various congenital and acquired diseases,including fibrosis and cancer.This review provides a summary of the various roles of Sox9 in cell fate specification,stem cell biology,and related human diseases.Ultimately,understanding the mechanisms that regulate Sox9 will be crucial for developing effective therapies to treat disease caused by stem cell dysregulation or even reverse organ damage.
基金The authors’ laboratories were supported in part byresearch grants from the National Institutes of Health(AR50142, AR054381, and AT004418 to RCH, HHL, and TCH)and Scoliosis Research Society (MJL)JDG and VT were recipientsof the Pritzker Summer Research Fellowship fundedthrough a NIH T-35 training grant (NIDDK)MKM was arecipient of Howard Hughes Medical Institute MedicalResearch Fellowship.
文摘Defects of articular cartilage present a unique clinical challenge due to its poor self-healing capacity and avascular nature.Current surgical treatment options do not ensure consistent regeneration of hyaline cartilage in favor of fibrous tissue.Here,we review the current understanding of the most important biological regulators of chondrogenesis and their interactions,to provide insight into potential applications for cartilage tissue engineering.These include various signaling pathways,including fibroblast growth factors(FGFs),transforming growth factor b(TGF-b)/bone morphogenic proteins(BMPs),Wnt/b-catenin,Hedgehog,Notch,hypoxia,and angiogenic signaling pathways.Transcriptional and epigenetic regulation of chondrogenesis will also be discussed.Advances in our understanding of these signaling pathways have led to promising advances in cartilage regeneration and tissue engineering.
基金This research was supported by the National Natural Science Foundation of China(U1732115)the China National Petroleum Corporation(KD200121)+1 种基金the Science and Technology Department of Henan Province(222102230054)the Henan Province Education Department of Key Scientific Research Project in Colleges and Universities(21B430012).
文摘Tungsten carbide(WC)-based materials are widely considered as the hydrogen evolution reaction(HER)process catalysts due to their“Pt-like”electronic structure.Nonetheless,traditional powder electrodes have a high cost,and display problems related to the process itself and the poor stability over operation time.This paper presented a self-supported asymmetric porous ceramic electrode with WO_(3-x)whiskers formed in situ on the walls of the finger-like holes and membrane surface,which was prepared by combining phase inversion tape-casting,pressureless sintering,and thermal treatment in a CO_(2) atmosphere.The optimized ceramic electrode displayed good catalytic HER activity and outstanding stability at high current densities.More specifically,it demonstrated the lowest overpotentials of 107 and 123 mV and the lowest Tafel slopes of 59.3 and 72.4 mV·dec^(-1)at 10 mA·cm^(-2)in acidic and alkaline media,respectively.This superior performance was ascribed to the structure of the ceramic membrane and the charge transfer efficiency,which was favored by the in situ developed WC/WO_(3-x)heterostructure and the oxygen vacancies.
基金supported by the National Natural Science Foundation of China(Grant No.51972045)the Fundamental Research Funds for the Chinese Central Universities,China(Grant No.ZYGX2019J025)the Sichuan Science and Technology Program(Grant Nos.2020JDRC0015 and 2020JDRC0045).
文摘Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herein,a low-cost,eco-friendly,simple-operating,and time-saving technique,named electrical discharge,is reviewed in relation to developments from the nature of this technique in different dielectric media to the practical experience in controlling the main processing parameters,apparatuses,types of discharge,from the various structures and components to the wide applications.The development of the electrical discharge technique will play an important role in improving the technology to prepare superfine inorganic particles with high purity.Meanwhile,electrical discharge contributes to easily mixing solid materials from the atomic scale to several micrometers with different structures.Moreover,metal oxides or doping materials are accessible as the dielectric medium is changed.Considering some excellent advantages,new inorganic particles exploited through the electrical discharge method will promise to be the most rewarding in some potential applications.
