Nano-kirigami technology enables the flexible transformation of two-dimensional(2D)micro/nanoscale structures into three-dimensional(3D)structures with either open-loop or close-loop topological morphologies,and has a...Nano-kirigami technology enables the flexible transformation of two-dimensional(2D)micro/nanoscale structures into three-dimensional(3D)structures with either open-loop or close-loop topological morphologies,and has aroused significant interest in the fields of nanophotonics and optoelectronics.Here,we propose an innovative kissing-loop nano-kirigami strategy,wherein 2D open-loop structures can transform into 3D kissing-loop structures while retaining advantages such as large deformation heights and multiple optical modulations.Benefited from the unidirectional deformation of the structures,the kissing-loop nano-kirigami exhibits significant asymmetric transmission under x-polarized light incidence.Importantly,the Pancharatnam-Berry geometric phase is experimentally realized in nano-kirigami structures for the first time,resulting in broadband anomalous reflection in the near-infrared wavelength region.The kissing-loop nano-kirigami strategy can expand the existing platform of micro/nanoscale fabrication and provide an effective method for developing optical sensing,spatial light modulations,and optoelectronic devices.展开更多
Dimers of tRNAs can form through quasi self-complementary anticodon-anticodon interactions, for example at neutral pH in yeast tRNAAsp(GUC) and at pH4.5 inEscherichia coli tRNAGly(GCC) through a partially protonated i...Dimers of tRNAs can form through quasi self-complementary anticodon-anticodon interactions, for example at neutral pH in yeast tRNAAsp(GUC) and at pH4.5 inEscherichia coli tRNAGly(GCC) through a partially protonated interaction. The requirements for tRNA oligomerization, and the factors that prevented higher orders of structures forming were examined with unmodified wild-type and variant E. coli tRNAsGly(GCC). Non-denaturing agarose gel electrophoresis was used as a rapid screening method. A number of tRNAGly(GCC) variants with nucleotide substitutions in the loop regions formed dimers, but surprisingly there was no evidence that distinct higher oligomers formed in any of the variants tested. The dimer interfaces of two of the variants were delineated by competitive inhibition with complementary DNA oligonucleotides. Components of an oligomerization facilitating buffer, containing monovalent, divalent and multivalent cations (magnesium and sodium ions and spermine), were tested separately and in combination, to optimize oligomerization and its detection using agarose gel electrophoresis. A rationale for the requirement for magnesium for dimerization is suggested from its role in RNA loop-loop interactions. Sequence specific variant tRNAs that can rapidly form heterodimers with damaging infectious RNA are potential therapeutic agents against viral mechanisms by acting as base pairing inhibitors.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.T2325005,62375016)Science and Technology Project of Guangdong(2020B010190001).
文摘Nano-kirigami technology enables the flexible transformation of two-dimensional(2D)micro/nanoscale structures into three-dimensional(3D)structures with either open-loop or close-loop topological morphologies,and has aroused significant interest in the fields of nanophotonics and optoelectronics.Here,we propose an innovative kissing-loop nano-kirigami strategy,wherein 2D open-loop structures can transform into 3D kissing-loop structures while retaining advantages such as large deformation heights and multiple optical modulations.Benefited from the unidirectional deformation of the structures,the kissing-loop nano-kirigami exhibits significant asymmetric transmission under x-polarized light incidence.Importantly,the Pancharatnam-Berry geometric phase is experimentally realized in nano-kirigami structures for the first time,resulting in broadband anomalous reflection in the near-infrared wavelength region.The kissing-loop nano-kirigami strategy can expand the existing platform of micro/nanoscale fabrication and provide an effective method for developing optical sensing,spatial light modulations,and optoelectronic devices.
文摘Dimers of tRNAs can form through quasi self-complementary anticodon-anticodon interactions, for example at neutral pH in yeast tRNAAsp(GUC) and at pH4.5 inEscherichia coli tRNAGly(GCC) through a partially protonated interaction. The requirements for tRNA oligomerization, and the factors that prevented higher orders of structures forming were examined with unmodified wild-type and variant E. coli tRNAsGly(GCC). Non-denaturing agarose gel electrophoresis was used as a rapid screening method. A number of tRNAGly(GCC) variants with nucleotide substitutions in the loop regions formed dimers, but surprisingly there was no evidence that distinct higher oligomers formed in any of the variants tested. The dimer interfaces of two of the variants were delineated by competitive inhibition with complementary DNA oligonucleotides. Components of an oligomerization facilitating buffer, containing monovalent, divalent and multivalent cations (magnesium and sodium ions and spermine), were tested separately and in combination, to optimize oligomerization and its detection using agarose gel electrophoresis. A rationale for the requirement for magnesium for dimerization is suggested from its role in RNA loop-loop interactions. Sequence specific variant tRNAs that can rapidly form heterodimers with damaging infectious RNA are potential therapeutic agents against viral mechanisms by acting as base pairing inhibitors.
