Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation ...Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.展开更多
We have successfully synthesized a novel diluted magnetic semiconductor(Ca_(1−2x)K_(2x))(Zn_(1−x)Mn_(x))_(2)As_(2) with decoupled charge and spin doping.The substitutions of(Ca^(2+),K^(+))and(Zn^(2+),Mn^(2+))in the pa...We have successfully synthesized a novel diluted magnetic semiconductor(Ca_(1−2x)K_(2x))(Zn_(1−x)Mn_(x))_(2)As_(2) with decoupled charge and spin doping.The substitutions of(Ca^(2+),K^(+))and(Zn^(2+),Mn^(2+))in the parent compound CaZn_(2)As_(2)(space group P m1(No.164))introduce carriers and magnetic moments,respectively.Doping only Mn into CaZn_(2)As_(2) does not induce any type of long range magnetic ordering.The ferromagnetic ordering arise can only when K^(+)and Mn^(2+)are simultaneously doped.The res-ulted maximum Curie temperature reaches~7 K,and the corresponding coercive field is~60 Oe.The transport measurements confirm that samples with K and Mn co-doping still behave like a semiconductor.展开更多
观察不同剂量As_(2)O_(3)联合^(125)I粒子植入对肺癌移植瘤小鼠的抑瘤作用和安全性。构建肺癌异种移植瘤小鼠模型,当肿瘤体积达到约300 mm 3时,将小鼠随机分为6组,连续治疗15 d。测量小鼠肿瘤瘤径、体重、饮食,检测小鼠血清ALT、AST、LD...观察不同剂量As_(2)O_(3)联合^(125)I粒子植入对肺癌移植瘤小鼠的抑瘤作用和安全性。构建肺癌异种移植瘤小鼠模型,当肿瘤体积达到约300 mm 3时,将小鼠随机分为6组,连续治疗15 d。测量小鼠肿瘤瘤径、体重、饮食,检测小鼠血清ALT、AST、LDH、CK、BUN、Cr浓度及脏器指数,HE染色评估主要脏器组织病理学变化。结果显示:与模型组相比,单用As_(2)O_(3)以及As_(2)O_(3)联合^(125)I粒子植入使小鼠饮食量和体重减少;单用As_(2)O_(3)(2.5 mg/kg、5 mg/kg)、^(125)I粒子(0.7 mci)治疗组以及联合治疗组均能明显抑制小鼠肿瘤生长(P<0.05);联合治疗组抑制作用优于单用As_(2)O_(3)和^(125)I粒子植入组(P<0.001);联合治疗组对小鼠血清生化功能及脏器指数无明显影响(P>0.05),组织病理学观察未见明显异常。综上,As_(2)O_(3)联合^(125)I粒子植入能够抑制肺癌移植瘤小鼠肿瘤生长,且优于单用As_(2)O_(3)和^(125)I粒子植入,方法安全可行。展开更多
目的探究雄黄主要成分二硫化二砷(As_(2)S_(2))对三阴性乳腺癌(triple negative breast cancer,TNBC)的作用及表观遗传调控机制。方法采用CCK-8、平板克隆形成和细胞划痕实验探究As_(2)S_(2)对人正常乳腺上皮细胞MCF-10A及TNBC细胞增殖...目的探究雄黄主要成分二硫化二砷(As_(2)S_(2))对三阴性乳腺癌(triple negative breast cancer,TNBC)的作用及表观遗传调控机制。方法采用CCK-8、平板克隆形成和细胞划痕实验探究As_(2)S_(2)对人正常乳腺上皮细胞MCF-10A及TNBC细胞增殖和迁移的影响;4D-label free定量蛋白质组学分析挖掘As_(2)S_(2)抗TNBC的潜在干预靶点酸性核磷蛋白家族成员32A(acidic nuclear phosphoprotein family member 32A,ANP32A);慢病毒感染法构建ANP32A过表达敲低细胞株,探究潜在靶点ANP32A对As_(2)S_(2)抗TNBC作用的影响;蛋白质免疫共沉淀和Western blot实验探究As_(2)S_(2)是否通过ANP32A调控TNBC细胞H3乙酰化。结果As_(2)S_(2)对人正常乳腺上皮细胞MCF-10A影响甚微,但显著抑制TNBC细胞增殖和迁移,且呈剂量依赖性;4D-lable free定量蛋白质组学分析结果显示,促癌因子ANP32A被As_(2)S_(2)显著下调,且ANP32A表达影响As_(2)S_(2)在TNBC中的抗增殖和迁移效果。As_(2)S_(2)能下调ANP32A的蛋白水平,抑制乙酰转移酶抑制剂复合物亚基的招募,增加H3乙酰化水平。结论As_(2)S_(2)通过下调ANP32A蛋白调控TNBC细胞中H3乙酰化,抑制TNBC细胞增殖和迁移。展开更多
Atomic characterization on tetragonal FeAs layer and engineering FeAs superlattices is highly desirable to get deep insight into the multi-band superconductivity in iron-pnictides.We fabricate the tetragonal FeAs laye...Atomic characterization on tetragonal FeAs layer and engineering FeAs superlattices is highly desirable to get deep insight into the multi-band superconductivity in iron-pnictides.We fabricate the tetragonal FeAs layer by topotactic reaction of FeTe films with arsenic and then obtain KxFe_(2)As_(2)upon potassium intercalation using molecular beam epitaxy.The in-situ low-temperature√2×√2scanning tunneling microscopy/spectroscopy investigations demonstrate characteristic reconstruction of the FeAs layer and stripe pattern of KxFe_(2)As_(2),accompanied by the development of a superconducting-like gap.The ex-situ transport measurement with FeTe capping layers shows a superconducting transition with an onset temperature of 10 K.This work provides a promising way to characterize the FeAs layer directly and explore rich emergent physics with epitaxial superlattice design.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant Nos.2020YFF01014706 and 2017YFC0601901)the National Natural Science Foundation of China (Grant Nos.61571019 and 52177026)。
文摘Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.
基金supported by the Key R&D Program of Zhejiang Province, China (2021C01002)NSF of China (No. 12074333)。
文摘We have successfully synthesized a novel diluted magnetic semiconductor(Ca_(1−2x)K_(2x))(Zn_(1−x)Mn_(x))_(2)As_(2) with decoupled charge and spin doping.The substitutions of(Ca^(2+),K^(+))and(Zn^(2+),Mn^(2+))in the parent compound CaZn_(2)As_(2)(space group P m1(No.164))introduce carriers and magnetic moments,respectively.Doping only Mn into CaZn_(2)As_(2) does not induce any type of long range magnetic ordering.The ferromagnetic ordering arise can only when K^(+)and Mn^(2+)are simultaneously doped.The res-ulted maximum Curie temperature reaches~7 K,and the corresponding coercive field is~60 Oe.The transport measurements confirm that samples with K and Mn co-doping still behave like a semiconductor.
文摘目的探究雄黄主要成分二硫化二砷(As_(2)S_(2))对三阴性乳腺癌(triple negative breast cancer,TNBC)的作用及表观遗传调控机制。方法采用CCK-8、平板克隆形成和细胞划痕实验探究As_(2)S_(2)对人正常乳腺上皮细胞MCF-10A及TNBC细胞增殖和迁移的影响;4D-label free定量蛋白质组学分析挖掘As_(2)S_(2)抗TNBC的潜在干预靶点酸性核磷蛋白家族成员32A(acidic nuclear phosphoprotein family member 32A,ANP32A);慢病毒感染法构建ANP32A过表达敲低细胞株,探究潜在靶点ANP32A对As_(2)S_(2)抗TNBC作用的影响;蛋白质免疫共沉淀和Western blot实验探究As_(2)S_(2)是否通过ANP32A调控TNBC细胞H3乙酰化。结果As_(2)S_(2)对人正常乳腺上皮细胞MCF-10A影响甚微,但显著抑制TNBC细胞增殖和迁移,且呈剂量依赖性;4D-lable free定量蛋白质组学分析结果显示,促癌因子ANP32A被As_(2)S_(2)显著下调,且ANP32A表达影响As_(2)S_(2)在TNBC中的抗增殖和迁移效果。As_(2)S_(2)能下调ANP32A的蛋白水平,抑制乙酰转移酶抑制剂复合物亚基的招募,增加H3乙酰化水平。结论As_(2)S_(2)通过下调ANP32A蛋白调控TNBC细胞中H3乙酰化,抑制TNBC细胞增殖和迁移。
基金supported by the National Natural Science Foundation of China(Nos.12074210,51788104,11790311,and 12141403)the Basic and Applied Basic Research Major Programme of Guangdong Province of China(No.2021B0301030003)Jihua Laboratory(Project No.X210141TL210).
文摘Atomic characterization on tetragonal FeAs layer and engineering FeAs superlattices is highly desirable to get deep insight into the multi-band superconductivity in iron-pnictides.We fabricate the tetragonal FeAs layer by topotactic reaction of FeTe films with arsenic and then obtain KxFe_(2)As_(2)upon potassium intercalation using molecular beam epitaxy.The in-situ low-temperature√2×√2scanning tunneling microscopy/spectroscopy investigations demonstrate characteristic reconstruction of the FeAs layer and stripe pattern of KxFe_(2)As_(2),accompanied by the development of a superconducting-like gap.The ex-situ transport measurement with FeTe capping layers shows a superconducting transition with an onset temperature of 10 K.This work provides a promising way to characterize the FeAs layer directly and explore rich emergent physics with epitaxial superlattice design.