Angle-resolved photoemission spectroscopy(ARPES)is one of the most powerful experimental techniques in condensed matter physics.Synchrotron ARPES,which uses photons with high flux and continuously tunable energy,has b...Angle-resolved photoemission spectroscopy(ARPES)is one of the most powerful experimental techniques in condensed matter physics.Synchrotron ARPES,which uses photons with high flux and continuously tunable energy,has become particularly important.However,an excellent synchrotron ARPES system must have features such as a small beam spot,super-high energy resolution,and a user-friendly operation interface.A synchrotron beamline and an endstation(BL03 U)were designed and constructed at the Shanghai Synchrotron Radiation Facility.The beam spot size at the sample position is 7.5(V)μm×67(H)μm,and the fundamental photon range is 7-165 eV;the ARPES system enables photoemission with an energy resolution of 2.67 meV at21.2 eV.In addition,the ARPES system of this endstation is equipped with a six-axis cryogenic sample manipulator(the lowest temperature is 7 K)and is integrated with an oxide molecular beam epitaxy system and a scanning tunneling microscope,which can provide an advanced platform for in situ characterization of the fine electronic structure of condensed matter.展开更多
Recently we developed a technique of ozone/vacuum annealing to continuously change the doping level of the surface of Bi_2Sr_2CaCu_2O_(8+)and measured a nearly whole superconducting dome on one surface by in-situ angl...Recently we developed a technique of ozone/vacuum annealing to continuously change the doping level of the surface of Bi_2Sr_2CaCu_2O_(8+)and measured a nearly whole superconducting dome on one surface by in-situ angle-resolved photoemission spectroscopy [arXiv: 1805.06450]. Here we study the evolution of the electronic structures of Bi_2Sr_2CaCu_2O_(8+)xusing this technique together with tight binding fits. The tight binding parameters are extracted to study their evolution with doping.展开更多
Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes...Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.展开更多
Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarge...Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.展开更多
目的:评价利用隧道技术,在前牙区缺牙位点应用去蛋白牛骨基质(Deproteinizedboving bone mineral,DBBM)和可吸收生物膜联合浓缩生长因子(Concentrate growth factors,CGF)行牙槽嵴保存技术,维持缺牙位点骨量的有效性。方法:收集2020年6...目的:评价利用隧道技术,在前牙区缺牙位点应用去蛋白牛骨基质(Deproteinizedboving bone mineral,DBBM)和可吸收生物膜联合浓缩生长因子(Concentrate growth factors,CGF)行牙槽嵴保存技术,维持缺牙位点骨量的有效性。方法:收集2020年6月-2022年6月来首都医科大学电力教学医院口腔科就诊需要进行前牙区牙槽嵴保存技术的患者共140例,按乱数表法分成两组,每组70例。试验组:在微创拔牙位点上,通过隧道技术,利用DBBM和可吸收生物膜联合CGF行牙槽嵴保存技术。对照组:微创拔牙后,牙槽窝内充填胶原蛋白海绵。术后6个月进行随访,利用CBCT观察和测量牙槽骨骨量的变化。结果:试验组中,唇、腭侧骨高度术后6个月和术前接近(P>0.05),骨宽度术后6个月比术前减少(P<0.05)。对照组中,唇、腭侧骨高度和骨宽度术后6个月比术前明显减少(P<0.05)。试验组的骨高度、骨宽度术后6个月和术前的差值明显少于对照组(P<0.05)。结论:利用隧道技术,在前牙区缺牙位点应用DBBM和Bio-Gide联合CGF行牙槽嵴保存术,能够有效维持拔牙位点的骨量,有益于后期种植体植入。展开更多
基金supported by the National Key R&D Program of the MOST of China(No.2016YFA0300204)the National Natural Science Foundation of China(No.11227902)as part of the SiP·ME2 beamline project。
文摘Angle-resolved photoemission spectroscopy(ARPES)is one of the most powerful experimental techniques in condensed matter physics.Synchrotron ARPES,which uses photons with high flux and continuously tunable energy,has become particularly important.However,an excellent synchrotron ARPES system must have features such as a small beam spot,super-high energy resolution,and a user-friendly operation interface.A synchrotron beamline and an endstation(BL03 U)were designed and constructed at the Shanghai Synchrotron Radiation Facility.The beam spot size at the sample position is 7.5(V)μm×67(H)μm,and the fundamental photon range is 7-165 eV;the ARPES system enables photoemission with an energy resolution of 2.67 meV at21.2 eV.In addition,the ARPES system of this endstation is equipped with a six-axis cryogenic sample manipulator(the lowest temperature is 7 K)and is integrated with an oxide molecular beam epitaxy system and a scanning tunneling microscope,which can provide an advanced platform for in situ characterization of the fine electronic structure of condensed matter.
基金supported by the Ministry of Science and Technology of China(Grant Nos.2016YFA0401000,2016YFA0300600,2015CB921300,and 2015CB921000)the National Natural Science Foundation of China(Grant Nos.11227903,and 11574371)and the Chinese Academy of Sciences(Grant Nos.XDB07000000,and XDPB08-1)
文摘Recently we developed a technique of ozone/vacuum annealing to continuously change the doping level of the surface of Bi_2Sr_2CaCu_2O_(8+)and measured a nearly whole superconducting dome on one surface by in-situ angle-resolved photoemission spectroscopy [arXiv: 1805.06450]. Here we study the evolution of the electronic structures of Bi_2Sr_2CaCu_2O_(8+)xusing this technique together with tight binding fits. The tight binding parameters are extracted to study their evolution with doping.
基金supported by the National Natural Science Foundation of China(Grant No.12074358)the National Key Research and Development Program of China(Grant No.2024YFA1408103)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(Grant No.123GJHZ2022035MI)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)the Fundamental Research Funds for the Central Universities(Grant No.WK3510000015)。
文摘Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.
文摘Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.
文摘目的:评价利用隧道技术,在前牙区缺牙位点应用去蛋白牛骨基质(Deproteinizedboving bone mineral,DBBM)和可吸收生物膜联合浓缩生长因子(Concentrate growth factors,CGF)行牙槽嵴保存技术,维持缺牙位点骨量的有效性。方法:收集2020年6月-2022年6月来首都医科大学电力教学医院口腔科就诊需要进行前牙区牙槽嵴保存技术的患者共140例,按乱数表法分成两组,每组70例。试验组:在微创拔牙位点上,通过隧道技术,利用DBBM和可吸收生物膜联合CGF行牙槽嵴保存技术。对照组:微创拔牙后,牙槽窝内充填胶原蛋白海绵。术后6个月进行随访,利用CBCT观察和测量牙槽骨骨量的变化。结果:试验组中,唇、腭侧骨高度术后6个月和术前接近(P>0.05),骨宽度术后6个月比术前减少(P<0.05)。对照组中,唇、腭侧骨高度和骨宽度术后6个月比术前明显减少(P<0.05)。试验组的骨高度、骨宽度术后6个月和术前的差值明显少于对照组(P<0.05)。结论:利用隧道技术,在前牙区缺牙位点应用DBBM和Bio-Gide联合CGF行牙槽嵴保存术,能够有效维持拔牙位点的骨量,有益于后期种植体植入。
