Daytime star images captured by dedicated near-space star sensors are characterized by short exposures,high noise,and low Signal-to-Noise Ratios(SNRs).Such imaging is also affected by atmospheric turbulence,causing op...Daytime star images captured by dedicated near-space star sensors are characterized by short exposures,high noise,and low Signal-to-Noise Ratios(SNRs).Such imaging is also affected by atmospheric turbulence,causing optical phenomena,such as scintillation,distortion,and jitter.This causes difficulty in recording high-precision star images during the daytime.This study proposes an adaptive star point extraction method based on dynamically predicting stars'positions.First,it predicts the approximate position of stars based on the star catalog,sensor attitude,observation time,and other information,improving the extraction accuracy.Second,it employs a regional SNR sorting method that adaptively selects star images with higher SNRs,suppressing the scintillation effect and enhancing the SNR of star images.Third,depending on the star's motion trajectory characteristics on the image plane,it utilizes the centroid smoothing method for extraction,thus overcoming the impact of star drift.Field experiments demonstrate that the proposed method can effectively overcome star scintillation,drift,and irregular imaging caused by atmospheric turbulence,achieving a 100%success rate.Moreover,the extraction accuracy improves by more than 80%compared to traditional adaptive methods,attaining a value of 0.05 pixels(0.5"),thereby meeting the requirements of daytime astronomical attitude determination and positioning.展开更多
Proanthocyanidins(PAs),also known as“condensed tannins”,are colorless metabolites produced through the flavonoid pathway that are involved in stress resistance in plants.Because PAs are involved in the anthocyanin b...Proanthocyanidins(PAs),also known as“condensed tannins”,are colorless metabolites produced through the flavonoid pathway that are involved in stress resistance in plants.Because PAs are involved in the anthocyanin biosynthetic pathway,they play a role in the modification of pigmentation conferred by anthocyanins in ornamental organs.In this study,we isolated the gene and functionally characterized an R2R3-MYB transcription factor(TF),AaMYB3,and a basic helix-loop-helix TF,AabHLH1,from Anthurium andraeanum(Hort.),a typical tropical flower.AaMYB3 is primarily expressed in the spathe and negatively correlates with anthocyanin accumulation.A complementation test in an Arabidopsis tt8 mutant showed that AabHLH1 successfully restores the PA-deficient seed coat phenotype.The ectopic overexpression of AaMYB3 alone or its coexpression with AabHLH1 in transgenic tobacco resulted in light pink or even pale-pink corolla limbs by reducing their anthocyanin levels and greatly enhancing their accumulation of PAs.This overexpression of the anthurium TF genes upregulated the late anthocyanin enzymeencoding genes(NtDFR and NtANS)and the key PA genes(NtLAR and NtANR)in transgenic tobacco.The interaction between AaMYB3 and the AabHLH1 protein was confirmed using yeast two-hybrid(Y2H)and bimolecular fluorescence complementation(BiFC)assays.In the developing red spathes of the cultivars“Vitara”and“Tropical”,the expression of AaMYB3 was closely linked to PA accumulation,and AaMYB3 was coexpressed with AaCHS,AaF3H,AaDFR,AaANS,AaLAR,and AaANR.The expression pattern of AabHLH1 was similar to that of AaF3′H.Our results suggest that AaMYB3 and AabHLH1 are involved in the regulation of PA biosynthesis in anthurium and could potentially be used to metabolically engineer PA biosynthesis in plants.展开更多
Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(...Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(GFETs)have been proven to be a promising platform for the rapid and accurate detection of small molecules,while the Debye shielding limits the sensitive detection in real samples.Here,a three-dimensional wrinkled graphene field-effect transistor(3D WG-FET)biosensor for ultra-sensitive detection of ATP is demonstrated.The lowest detection limit of 3D WG-FET for analyzing ATP is down to 3.01 aM,which is much lower than the reported results.In addition,the 3D WG-FET biosensor shows a good linear electrical response to ATP concentrations in a broad range of detection from 10 aM to 10 pM.Meanwhile,we achieved ultra-sensitive(LOD:10 aM)and quantitative(range from 10 aM to 100 fM)measurements of ATP in human serum.The 3D WG-FET also exhibits high specificity.This work may provide a novel approach to improve the sensitivity for the detection of ATP in complex biological matrix,showing a broad application value for early clinical diagnosis and food health monitoring.展开更多
基金funded by the National Natural Science Foundation of China(Nos.42374011,42074013)through the Natural Science Foundation’s Outstanding Youth Fund Program of Henan Province,China(Nos.242300421150,242300421151)。
文摘Daytime star images captured by dedicated near-space star sensors are characterized by short exposures,high noise,and low Signal-to-Noise Ratios(SNRs).Such imaging is also affected by atmospheric turbulence,causing optical phenomena,such as scintillation,distortion,and jitter.This causes difficulty in recording high-precision star images during the daytime.This study proposes an adaptive star point extraction method based on dynamically predicting stars'positions.First,it predicts the approximate position of stars based on the star catalog,sensor attitude,observation time,and other information,improving the extraction accuracy.Second,it employs a regional SNR sorting method that adaptively selects star images with higher SNRs,suppressing the scintillation effect and enhancing the SNR of star images.Third,depending on the star's motion trajectory characteristics on the image plane,it utilizes the centroid smoothing method for extraction,thus overcoming the impact of star drift.Field experiments demonstrate that the proposed method can effectively overcome star scintillation,drift,and irregular imaging caused by atmospheric turbulence,achieving a 100%success rate.Moreover,the extraction accuracy improves by more than 80%compared to traditional adaptive methods,attaining a value of 0.05 pixels(0.5"),thereby meeting the requirements of daytime astronomical attitude determination and positioning.
基金supported financially by the Hainan Provincial Natural Science Foundation of China(No.2018CXTD344)the Central Public-Interest Scientific Institution Basal Research Fund for the Chinese Academy of Tropical Agricultural Sciences(Nos.1630032017074 and 1630032017024).
文摘Proanthocyanidins(PAs),also known as“condensed tannins”,are colorless metabolites produced through the flavonoid pathway that are involved in stress resistance in plants.Because PAs are involved in the anthocyanin biosynthetic pathway,they play a role in the modification of pigmentation conferred by anthocyanins in ornamental organs.In this study,we isolated the gene and functionally characterized an R2R3-MYB transcription factor(TF),AaMYB3,and a basic helix-loop-helix TF,AabHLH1,from Anthurium andraeanum(Hort.),a typical tropical flower.AaMYB3 is primarily expressed in the spathe and negatively correlates with anthocyanin accumulation.A complementation test in an Arabidopsis tt8 mutant showed that AabHLH1 successfully restores the PA-deficient seed coat phenotype.The ectopic overexpression of AaMYB3 alone or its coexpression with AabHLH1 in transgenic tobacco resulted in light pink or even pale-pink corolla limbs by reducing their anthocyanin levels and greatly enhancing their accumulation of PAs.This overexpression of the anthurium TF genes upregulated the late anthocyanin enzymeencoding genes(NtDFR and NtANS)and the key PA genes(NtLAR and NtANR)in transgenic tobacco.The interaction between AaMYB3 and the AabHLH1 protein was confirmed using yeast two-hybrid(Y2H)and bimolecular fluorescence complementation(BiFC)assays.In the developing red spathes of the cultivars“Vitara”and“Tropical”,the expression of AaMYB3 was closely linked to PA accumulation,and AaMYB3 was coexpressed with AaCHS,AaF3H,AaDFR,AaANS,AaLAR,and AaANR.The expression pattern of AabHLH1 was similar to that of AaF3′H.Our results suggest that AaMYB3 and AabHLH1 are involved in the regulation of PA biosynthesis in anthurium and could potentially be used to metabolically engineer PA biosynthesis in plants.
基金support from the National Natural Science Foundation of China(Nos.12274058 and 12104085)Taishan Scholars Program of Shandong Province(No.tsqn201812104)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2021QA008)the Qingchuang Science and Technology Plan of Shandong Province(No.2019KJJ017)the project of the Talent Introduction of Dezhou University(No.2021xjrc101).
文摘Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(GFETs)have been proven to be a promising platform for the rapid and accurate detection of small molecules,while the Debye shielding limits the sensitive detection in real samples.Here,a three-dimensional wrinkled graphene field-effect transistor(3D WG-FET)biosensor for ultra-sensitive detection of ATP is demonstrated.The lowest detection limit of 3D WG-FET for analyzing ATP is down to 3.01 aM,which is much lower than the reported results.In addition,the 3D WG-FET biosensor shows a good linear electrical response to ATP concentrations in a broad range of detection from 10 aM to 10 pM.Meanwhile,we achieved ultra-sensitive(LOD:10 aM)and quantitative(range from 10 aM to 100 fM)measurements of ATP in human serum.The 3D WG-FET also exhibits high specificity.This work may provide a novel approach to improve the sensitivity for the detection of ATP in complex biological matrix,showing a broad application value for early clinical diagnosis and food health monitoring.
