Flexible photodetector(PD)arrays have the potential to replace the rods and cones in the retina,converting external light signals into electrical signals and offering hope for blind patients to regain vision.However,i...Flexible photodetector(PD)arrays have the potential to replace the rods and cones in the retina,converting external light signals into electrical signals and offering hope for blind patients to regain vision.However,issues like discontinuous electrode surfaces and incompletely crystallized perovskites can cause cracks and degrade the performance of flexible PDs during repeated bending,hindering their development and applications.In this study,we employ a combination of radio frequency magnetron sputtering and angular ion beam polishing to achieve an ultrathin,ultrasmooth platinum(Pt)electrode film(UTPF)with a thickness of less than 10 nm.Building on this,a vapor deposition method with dynamically regulated evaporation rates is developed to obtain a dense-gradient PbI_(2)precursor.This funnel-shaped vertical structure precursor facilitates the penetration of CH_(3)NH_(3)I solution,ultimately resulting in a dense and uniform perovskite film with large grains and strong interfacial bonding with UTPF.The results indicate that the flexible PD arrays exhibit excellent optoelectronic performances,characterized by high sensitivity,detectivity and a large on/off current ratio.Furthermore,benefitting from their exceptional flexibility and electrical stability,the devices retain 92.53%of the original photocurrent after 4000 bending cycles at large angles.Notably,the integrated 10×10 flexible PD arrays demonstrate good uniformity in dark current and photocurrent,along with high imaging resolution,showing the reliable imaging capabilities of the flexible arrays and their potential applications in artificial retina.展开更多
At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allo...At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allows for a more detailed investigation of processes that are normally telescoped to the point of being irresolvable.Very minor platinum-group element(PGE)展开更多
Phenylethanoid glycosides(PhGs)are a group of important natural products widely distributed in medicinal plants and known for their remarkable pharmacological properties.Uridine diphosphate(UDP)glycosyltransferase 79G...Phenylethanoid glycosides(PhGs)are a group of important natural products widely distributed in medicinal plants and known for their remarkable pharmacological properties.Uridine diphosphate(UDP)glycosyltransferase 79G15(UGT79G15)from Rehmannia glutinosa catalyzes the conversion of osmanthuside A to osmanthuside B,a key intermediate in the PhG biosynthetic pathway,through the formation of a(1→3)glycosidic bond.In this study,we present the crystal structures of UGT79G15 in its apo form,UDP-bound form,and,notably,its ternary complex containing UDP and a mimic acceptor,forsythiaside A,within its active site.Structural and comparative analyses revealed that UGT79G15 possesses a distinctive funnel-shaped acceptor-binding pocket with a small auxiliary cavity capable of accommodating the 4′-hydroxycinnamoyl group of PhGs,explaining the enzyme’s regiospecificity toward the 3′-OH of the acceptor.Additional structural examination and site-directed mutagenesis identified key residues that recognize and stabilize UDP-rhamnose and the sugar acceptor.Among the variants generated,I204W exhibits enhanced catalytic efficiency for osmanthuside A conversion,reaching up to 2.2-fold higher activity than the wild type.This study provides mechanistic insight into the donor specificity and acceptor regioselectivity of PhG 1,3-rhamnosyltransferase and expands the structural understanding of plant UGTs.展开更多
基金supported by the National Natural Science Foundation of China(62375081,U22A20138,52372146,62090035,52221001,and 52402181)the National Key R&D Program of China(2022YFA1204300 and 2022YFA1402501).
文摘Flexible photodetector(PD)arrays have the potential to replace the rods and cones in the retina,converting external light signals into electrical signals and offering hope for blind patients to regain vision.However,issues like discontinuous electrode surfaces and incompletely crystallized perovskites can cause cracks and degrade the performance of flexible PDs during repeated bending,hindering their development and applications.In this study,we employ a combination of radio frequency magnetron sputtering and angular ion beam polishing to achieve an ultrathin,ultrasmooth platinum(Pt)electrode film(UTPF)with a thickness of less than 10 nm.Building on this,a vapor deposition method with dynamically regulated evaporation rates is developed to obtain a dense-gradient PbI_(2)precursor.This funnel-shaped vertical structure precursor facilitates the penetration of CH_(3)NH_(3)I solution,ultimately resulting in a dense and uniform perovskite film with large grains and strong interfacial bonding with UTPF.The results indicate that the flexible PD arrays exhibit excellent optoelectronic performances,characterized by high sensitivity,detectivity and a large on/off current ratio.Furthermore,benefitting from their exceptional flexibility and electrical stability,the devices retain 92.53%of the original photocurrent after 4000 bending cycles at large angles.Notably,the integrated 10×10 flexible PD arrays demonstrate good uniformity in dark current and photocurrent,along with high imaging resolution,showing the reliable imaging capabilities of the flexible arrays and their potential applications in artificial retina.
文摘At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allows for a more detailed investigation of processes that are normally telescoped to the point of being irresolvable.Very minor platinum-group element(PGE)
基金supported by the National Key Research and Development Program(2020YFA0907800)the Innovation Fund of Haihe Laboratory of Synthetic Biology(22HHSWSS00023)+3 种基金the Science and Technology Program of Tianjin(24ZYJDSS00300)the National Natural Science Foundation of China(31970065)the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-PTJJ-007-07)the Competitive Support Program of the Tianjin Institute of Industrial Biotechnology,Chinese Academy of Sciences(JZ2024-037).
文摘Phenylethanoid glycosides(PhGs)are a group of important natural products widely distributed in medicinal plants and known for their remarkable pharmacological properties.Uridine diphosphate(UDP)glycosyltransferase 79G15(UGT79G15)from Rehmannia glutinosa catalyzes the conversion of osmanthuside A to osmanthuside B,a key intermediate in the PhG biosynthetic pathway,through the formation of a(1→3)glycosidic bond.In this study,we present the crystal structures of UGT79G15 in its apo form,UDP-bound form,and,notably,its ternary complex containing UDP and a mimic acceptor,forsythiaside A,within its active site.Structural and comparative analyses revealed that UGT79G15 possesses a distinctive funnel-shaped acceptor-binding pocket with a small auxiliary cavity capable of accommodating the 4′-hydroxycinnamoyl group of PhGs,explaining the enzyme’s regiospecificity toward the 3′-OH of the acceptor.Additional structural examination and site-directed mutagenesis identified key residues that recognize and stabilize UDP-rhamnose and the sugar acceptor.Among the variants generated,I204W exhibits enhanced catalytic efficiency for osmanthuside A conversion,reaching up to 2.2-fold higher activity than the wild type.This study provides mechanistic insight into the donor specificity and acceptor regioselectivity of PhG 1,3-rhamnosyltransferase and expands the structural understanding of plant UGTs.
