Let B（H） be the C^＊-algebra of all bounded linear operators on a complex Hilbert space H. It is proved that an additive surjective map φ on B（H） preserving the star partial order in both directions if and only i...Let B（H） be the C^＊-algebra of all bounded linear operators on a complex Hilbert space H. It is proved that an additive surjective map φ on B（H） preserving the star partial order in both directions if and only if one of the following assertions holds. （1） There exist a nonzero complex number a and two unitary operators U and V on H such that φ（X） = a UXV or φ（X） = α UX^＊ V for all X ∈B（H）. （2） There exist a nonzero a and two anti-unitary operators U and V on H such that φ（X） = αUXV or φ（X） = aUX^＊ Vfor all X∈ B（H）.展开更多
Orderly hierarchical structure with balanced mechanical,chemical,and electrical properties is the basis of the natural bone microenvironment.Inspired by nature,we developed a piezocatalytically-induced controlled mine...Orderly hierarchical structure with balanced mechanical,chemical,and electrical properties is the basis of the natural bone microenvironment.Inspired by nature,we developed a piezocatalytically-induced controlled mineralization strategy using piezoelectric polymer poly-L-lactic acid(PLLA)fibers with ordered micro-nano structures to prepare biomimetic tissue engineering scaffolds with a bone-like microenvironment(pcm-PLLA),in which PLLA-mediated piezoelectric catalysis promoted the in-situ polymerization of dopamine and subsequently regulated the controllable growth of hydroxyapatite crystals on the fiber surface.PLLA fibers,as analogs of mineralized collagen fibers,were arranged in an oriented manner,and ultimately formed a bone-like interconnected pore structure;in addition,they also provided bone-like piezoelectric properties.The uniformly sized HA nanocrystals formed by controlled mineralization provided a bone-like mechanical strength and chemical environment.The pcm-PLLA scaffold could rapidly recruit endogenous stem cells,and promote their osteogenic differentiation by activating cell membrane calcium channels and PI3K signaling pathways through ultrasound-responsive piezoelectric signals.In addition,the scaffold also provided a suitable microenvironment to promote macrophage M2 polarization and angiogenesis,thereby enhancing bone regeneration in skull defects of rats.The proposed piezocatalytically-induced controllable mineralization strategy provides a new idea for the development of tissue engineering scaffolds that can be implemented for multimodal physical stimulation therapy.展开更多
Catalytic therapy based on piezoelectric nanoparticles has become one of the effective strategies to eliminate tumors.However,it is still a challenge to improve the tumor delivery efficiency of piezoelectric nanoparti...Catalytic therapy based on piezoelectric nanoparticles has become one of the effective strategies to eliminate tumors.However,it is still a challenge to improve the tumor delivery efficiency of piezoelectric nanoparticles,so that they can penetrate normal tissues while specifically aggregating at tumor sites and subsequently generating large amounts of reactive oxygen species(ROS)to achieve precise and efficient tumor clearance.In the present study,we successfully fabricated tumor microenvironment-responsive assembled barium titanate nanoparticles(tma-BTO NPs):in the neutral pH environment of normal tissues,tma-BTO NPs were monodisperse and possessed the ability to cross the intercellular space;whereas,the acidic environment of the tumor triggered the self-assembly of tma-BTO NPs to form submicron-scale aggregates,and deposited in the tumor microenvironment.The self-assembled tma-BTO NPs not only caused mechanical damage to tumor cells;more interestingly,they also exhibited enhanced piezoelectric catalytic efficiency and produced more ROS than monodisperse nanoparticles under ultrasonic excitation,attributed to the mutual extrusion of neighboring particles within the confined space of the assembly.tma-BTO NPs exhibited differential cytotoxicity against tumor cells and normal cells,and the stronger piezoelectric catalysis and mechanical damage induced by the assemblies resulted in significant apoptosis of mouse breast cancer cells(4T1);while there was little damage to mouse embryo osteoblast precursor cells(MC3T3-E1)under the same treatment conditions.Animal experiments confirmed that peritumoral injection of tma-BTO NPs combined with ultrasound therapy can effectively inhibit tumor progression non-invasively.The tumor microenvironment-responsive self-assembly strategy opens up new perspectives for future precise piezoelectric-catalyzed tumor therapy.展开更多
Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering...Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering inflammatory cell infiltration and increased release of inflammatory cytokines.Some studies have shown that the inflammatory response may be related to the early occurrence of AF.The most direct way to inhibit perioperative inflammation is to use anti-inflammatory drugs such as glucocorticoids.Here,we prepared polylactic-co-glycolic acid(PLGA)nanoparticles loaded with budesonide(BUD)and delivered them through irrigation of saline during the onset of ablation.Local high temperature promoted local rupture of PLGA nanoparticles,releasing BUD,and produced a timely and effective local myocardial anti-inflammatory effect,resulting in the reduction of acute hematoma and inflammatory cell infiltration and the enhancement of ablation effect.Nanoparticles would also infiltrate into the local myocardium and gradually release BUD ingredients to produce a continuous antiinflammatory effect in the next few days.This resulted in a decrease in the level of inflammatory cytokine IL-6 and an increase of anti-inflammatory cytokine IL-10.This study explored an extraordinary drug delivery strategy to reduce ablation-related inflammation,which may prevent early recurrence of AF.展开更多
Cells generate traction forces by interacting with the extracellular matrix(ECM)during migration,contraction,invasion,and spreading.Cell-traction forces(CTFs)are extremely small but have enormous biological effects.It...Cells generate traction forces by interacting with the extracellular matrix(ECM)during migration,contraction,invasion,and spreading.Cell-traction forces(CTFs)are extremely small but have enormous biological effects.It has been discovered that CTFs serve a crucial role in regulating proliferation,differentiation,wound healing,morphogenesis,angiogenesis,inflammation,and tumor genesis by working together with biochemical signals to maintain a coherent framework for these processes.展开更多
基金The NSF(11371233)of Chinathe Fundamental Research Funds(GK201301007)for the Central Universities
文摘Let B（H） be the C^＊-algebra of all bounded linear operators on a complex Hilbert space H. It is proved that an additive surjective map φ on B（H） preserving the star partial order in both directions if and only if one of the following assertions holds. （1） There exist a nonzero complex number a and two unitary operators U and V on H such that φ（X） = a UXV or φ（X） = α UX^＊ V for all X ∈B（H）. （2） There exist a nonzero a and two anti-unitary operators U and V on H such that φ（X） = αUXV or φ（X） = aUX^＊ Vfor all X∈ B（H）.
基金supported by Beijing Natural Science Foundation(L212010)the National Natural Science Foundation of China(T2125003,52372174)+1 种基金the New Cornerstone Science Foundation,Major Instrument Project of the National Natural Science Foundation of China(22027810)the National Key Research and Development Program of China(2022YFB3804703,2022YFE0111700,2021YFA1200900,2021YFB3201204,2022YFB3205602)。
文摘Orderly hierarchical structure with balanced mechanical,chemical,and electrical properties is the basis of the natural bone microenvironment.Inspired by nature,we developed a piezocatalytically-induced controlled mineralization strategy using piezoelectric polymer poly-L-lactic acid(PLLA)fibers with ordered micro-nano structures to prepare biomimetic tissue engineering scaffolds with a bone-like microenvironment(pcm-PLLA),in which PLLA-mediated piezoelectric catalysis promoted the in-situ polymerization of dopamine and subsequently regulated the controllable growth of hydroxyapatite crystals on the fiber surface.PLLA fibers,as analogs of mineralized collagen fibers,were arranged in an oriented manner,and ultimately formed a bone-like interconnected pore structure;in addition,they also provided bone-like piezoelectric properties.The uniformly sized HA nanocrystals formed by controlled mineralization provided a bone-like mechanical strength and chemical environment.The pcm-PLLA scaffold could rapidly recruit endogenous stem cells,and promote their osteogenic differentiation by activating cell membrane calcium channels and PI3K signaling pathways through ultrasound-responsive piezoelectric signals.In addition,the scaffold also provided a suitable microenvironment to promote macrophage M2 polarization and angiogenesis,thereby enhancing bone regeneration in skull defects of rats.The proposed piezocatalytically-induced controllable mineralization strategy provides a new idea for the development of tissue engineering scaffolds that can be implemented for multimodal physical stimulation therapy.
基金supported by National Key Research and Development Program of China(2022YFE0111700,2021YFB3201204)the National Natural Science Foundation of China(T2125003,52372174)+2 种基金the open project of State Drug Administration Key Laboratory of Oral Materials(PKUSS20210401)the Beijing Natural Science Foundation(JQ20038,L212010)the Fundamental Research Funds for the Central Universities,and the Scientific Research Project of Guangdong Provincial Education Department(2022KTSCX118).
文摘Catalytic therapy based on piezoelectric nanoparticles has become one of the effective strategies to eliminate tumors.However,it is still a challenge to improve the tumor delivery efficiency of piezoelectric nanoparticles,so that they can penetrate normal tissues while specifically aggregating at tumor sites and subsequently generating large amounts of reactive oxygen species(ROS)to achieve precise and efficient tumor clearance.In the present study,we successfully fabricated tumor microenvironment-responsive assembled barium titanate nanoparticles(tma-BTO NPs):in the neutral pH environment of normal tissues,tma-BTO NPs were monodisperse and possessed the ability to cross the intercellular space;whereas,the acidic environment of the tumor triggered the self-assembly of tma-BTO NPs to form submicron-scale aggregates,and deposited in the tumor microenvironment.The self-assembled tma-BTO NPs not only caused mechanical damage to tumor cells;more interestingly,they also exhibited enhanced piezoelectric catalytic efficiency and produced more ROS than monodisperse nanoparticles under ultrasonic excitation,attributed to the mutual extrusion of neighboring particles within the confined space of the assembly.tma-BTO NPs exhibited differential cytotoxicity against tumor cells and normal cells,and the stronger piezoelectric catalysis and mechanical damage induced by the assemblies resulted in significant apoptosis of mouse breast cancer cells(4T1);while there was little damage to mouse embryo osteoblast precursor cells(MC3T3-E1)under the same treatment conditions.Animal experiments confirmed that peritumoral injection of tma-BTO NPs combined with ultrasound therapy can effectively inhibit tumor progression non-invasively.The tumor microenvironment-responsive self-assembly strategy opens up new perspectives for future precise piezoelectric-catalyzed tumor therapy.
基金the National Natural Science Foundation of China(61875015,T2125003,82100335,81870310,and 81200194)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16021101)the Beijing Natural Science Foundation(JQ20038 and L212010).
文摘Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering inflammatory cell infiltration and increased release of inflammatory cytokines.Some studies have shown that the inflammatory response may be related to the early occurrence of AF.The most direct way to inhibit perioperative inflammation is to use anti-inflammatory drugs such as glucocorticoids.Here,we prepared polylactic-co-glycolic acid(PLGA)nanoparticles loaded with budesonide(BUD)and delivered them through irrigation of saline during the onset of ablation.Local high temperature promoted local rupture of PLGA nanoparticles,releasing BUD,and produced a timely and effective local myocardial anti-inflammatory effect,resulting in the reduction of acute hematoma and inflammatory cell infiltration and the enhancement of ablation effect.Nanoparticles would also infiltrate into the local myocardium and gradually release BUD ingredients to produce a continuous antiinflammatory effect in the next few days.This resulted in a decrease in the level of inflammatory cytokine IL-6 and an increase of anti-inflammatory cytokine IL-10.This study explored an extraordinary drug delivery strategy to reduce ablation-related inflammation,which may prevent early recurrence of AF.
基金supported by the National Natural Science Foundation of China(82102231,T2125003,and 61875015)the China Postdoctoral Science Foundation(2020M680302 and 2021T140041)the Beijing Natural Science Foundation(JQ20038).
文摘Cells generate traction forces by interacting with the extracellular matrix(ECM)during migration,contraction,invasion,and spreading.Cell-traction forces(CTFs)are extremely small but have enormous biological effects.It has been discovered that CTFs serve a crucial role in regulating proliferation,differentiation,wound healing,morphogenesis,angiogenesis,inflammation,and tumor genesis by working together with biochemical signals to maintain a coherent framework for these processes.
