Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the ele...Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures.展开更多
基金Project supported by the Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University(Grant No.2020-520000-83-01-324061)the National Natural Science Foundation of China(Grant No.61264004)the High-level Creative Talent Training Program in Guizhou Province of China(Grant No.[2015]4015).
文摘Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures.
文摘目的:探究长链非编码RNA(long non-coding RNA,lncRNA)H19对乳腺癌细胞顺铂(cisplatin/cisdiamminodichloroplatinum,DDP)耐药性的作用及其分子机制。方法:构建耐DDP人乳腺癌细胞株MCF7-Re;采用RT-qPCR检测lncRNA H19在人正常乳腺上皮细胞株MCF10A及人乳腺癌细胞株MCF7和MCF7-Re中的表达水平。构建lncRNA H19干扰质粒;采用CCK-8法检测DDP处理后MCF7-Re细胞的活力;采用TUNEL法检测细胞凋亡;Western blot检测Bcl-2、Bax、cleaved caspase-3、ATP结合盒蛋白B亚家族成员1(ATP-binding cassette protein subfamily B member 1,ABCB1)、Notch1和发状分裂相关增强子1(hairy and enhancer of split 1,Hes1)的表达;构建Notch1过表达质粒,进行逆转实验验证lncRNA H19的作用机制。结果:lncRNA H19在MCF7-Re细胞中表达显著增加。干扰H19在DDP处理后进一步降低MCF7-Re细胞活力(P<0.01),耐药蛋白ABCB1表达显著降低(P<0.01),细胞凋亡率显著升高(P<0.01),Bcl-2蛋白表达显著减少(P<0.01),Bax和cleaved caspase-3蛋白表达显著增加(P<0.01),并且Notch信号通路相关蛋白(Notch1和Hes1)的表达减少(P<0.01)。转染Notch1过表达质粒后,干扰lncRNA H19表达的MCF7-Re细胞活力得到一定程度的上升(P<0.01),耐药蛋白ABCB1表达显著增加(P<0.01),细胞凋亡率显著降低(P<0.01),Bcl-2蛋白表达显著增加(P<0.01),Bax和cleaved caspase-3蛋白表达显著减少(P<0.01)。结论:干扰lncRNA H19通过抑制Notch信号通路抑制耐DDP乳腺癌细胞的增殖,并增强该细胞对DDP的敏感性。
