Legume symbiotic nitrogen fixation(SNF)is suppressed by inorganic nitrogen(N)in the soil.High N inhibition of nitrogenase activity is associated with the deprivation of carbon allocation and metabolism in nodules.Howe...Legume symbiotic nitrogen fixation(SNF)is suppressed by inorganic nitrogen(N)in the soil.High N inhibition of nitrogenase activity is associated with the deprivation of carbon allocation and metabolism in nodules.However,the underlying molecular mechanisms remain unclear.Here,we identify Gm CIN1,which encodes a cytosolic invertase,as a gateway for the N-tuning of sucrose utilization in nodules.Gm CIN1 is enriched in mature soybean nodules,and its expression is regulated by nitrogen status.The knockout of Gm CIN1 using genome editing partially mimics the inhibitory effects of N on nitrogenase activity and sugar content and the impact of high N on nodule transcriptomes.This indicates that Gm CIN1 partially mediates the high N inhibition of nodule activity.Moreover,Ch IP-q PCR and EMSA reveal that SNAP1/2 transcription factors directly bind to the Gm CIN1 promoter.In addition,SNAP1/2 may be involved in the repression of Gm CIN1 expression in mature nodules at high N concentrations.Our findings provide insights into the involvement of the transcriptional tuning of carbon(C)metabolism genes by N-signaling modulators in the N-induced inhibition of nitrogenase activity.展开更多
Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformati...Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformation.In this study,high-resolution transmission electron microscopy(HRTEM)and molecular dy-namics(MD)simulations were used to investigate the atomic arrangements and crystalline defects of deformation-induced γ-austenite→ε-martensite→α'-martensite and γ→α'martensitic transforma-tions in 316 L SS at 15 and 173 K.Theγ→εtransformation involves the glide of Shockley partial dislocations on(111)γplanes without a change in atomic spacing.The formation of anα'inclusion in a singleε-band is achieved by a continuous lattice distortion,accompanied by the formation of a tran-sition zone ofα'and the expansion of the average atomic spacings due to dislocation shuffling.Asα'grows further intoγ,the orientation relationship(OR)of theα'changes by lattice bending.This pro-cess follows the Bogers-Burgers-Olson-Cohen model despite it not occurring on intersecting shear bands.Stacking faults and twins can also serve as nucleation sites forα'at 173 K.We also found that direct transformation of γ→α'occurs by the glide of √6aγ[11(2)]/12 dislocations on every(111)γplane with misfit dislocations.Overall,this study provides,for the first time,insights into the atomic-scale mech-anisms of various two-step and one-step martensitic transformations induced by cryogenic deformation and corresponding local strain,enhancing our understanding of the role of martensitic transformation under ultra-cryogenic-temperature deformation in controlling the properties.展开更多
Objective To evaluate the prevalence,awareness,treatment and control rate of hypertension among elder population in China.Methods Data form a cross-sectional stratified multistage random sampling survey conducted from...Objective To evaluate the prevalence,awareness,treatment and control rate of hypertension among elder population in China.Methods Data form a cross-sectional stratified multistage random sampling survey conducted from 2012 to 2015 were used to analyzed.Finally,a total of 134,397 participants aged≥60 years were enrolled in our study.Hypertension was defined as systolic BP≥140 mmHg,and/or diastolic BP≥90 mmHg,and/or use of antihypertensive medicine within 2 weeks.Among participants with hypertension,control rate of hypertension was defined as the participant presenting as hypertensive,but with a systolic BP measure less than 140 mm Hg and diastolic BP measure less than 90 mm Hg.展开更多
Recently,the emergence of single-cell RNA-sequencing(scRNA-seq)technology makes it possible to solve biological problems at the single-cell resolution.One of the critical steps in cellular heterogeneity analysis is th...Recently,the emergence of single-cell RNA-sequencing(scRNA-seq)technology makes it possible to solve biological problems at the single-cell resolution.One of the critical steps in cellular heterogeneity analysis is the cell type identification.Diverse scRNA-seq clustering methods have been proposed to partition cells into clusters.Among all the methods,hierarchical clustering and spectral clustering are the most popular approaches in the downstream clustering analysis with different preprocessing strategies such as similarity learning,dropout imputation,and dimensionality reduction.In this study,we carry out a comprehensive analysis by combining different strategies with these two categories of clustering methods on scRNA-seq datasets under different biological conditions.The analysis results show that the methods with spectral clustering tend to perform better on datasets with continuous shapes in two-dimension,while those with hierarchical clustering achieve better results on datasets with obvious boundaries between clusters in two-dimension.Motivated by this finding,a new strategy,called QRS,is developed to quantitatively evaluate the latent representative shape of a dataset to distinguish whether it has clear boundaries or not.Finally,a data-driven clustering recommendation method,called DDCR,is proposed to recommend hierarchical clustering or spectral clustering for scRNA-seq data.We perform DDCR on two typical single cell clustering methods,SC3 and RAFSIL,and the results show that DDCR recommends a more suitable downstream clustering method for different scRNA-seq datasets and obtains more robust and accurate results.展开更多
基金supported by funds from the National Natural Science Foundation of China(32072083)a Guangzhou Science Grant(2024A03J0010)awarded to Y.G。
文摘Legume symbiotic nitrogen fixation(SNF)is suppressed by inorganic nitrogen(N)in the soil.High N inhibition of nitrogenase activity is associated with the deprivation of carbon allocation and metabolism in nodules.However,the underlying molecular mechanisms remain unclear.Here,we identify Gm CIN1,which encodes a cytosolic invertase,as a gateway for the N-tuning of sucrose utilization in nodules.Gm CIN1 is enriched in mature soybean nodules,and its expression is regulated by nitrogen status.The knockout of Gm CIN1 using genome editing partially mimics the inhibitory effects of N on nitrogenase activity and sugar content and the impact of high N on nodule transcriptomes.This indicates that Gm CIN1 partially mediates the high N inhibition of nodule activity.Moreover,Ch IP-q PCR and EMSA reveal that SNAP1/2 transcription factors directly bind to the Gm CIN1 promoter.In addition,SNAP1/2 may be involved in the repression of Gm CIN1 expression in mature nodules at high N concentrations.Our findings provide insights into the involvement of the transcriptional tuning of carbon(C)metabolism genes by N-signaling modulators in the N-induced inhibition of nitrogenase activity.
基金supported by the Henry Royce Institute for Advanced Materials,funded through Engineering and Physical Sciences Research Council(EPSRC)grants EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1.
文摘Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformation.In this study,high-resolution transmission electron microscopy(HRTEM)and molecular dy-namics(MD)simulations were used to investigate the atomic arrangements and crystalline defects of deformation-induced γ-austenite→ε-martensite→α'-martensite and γ→α'martensitic transforma-tions in 316 L SS at 15 and 173 K.Theγ→εtransformation involves the glide of Shockley partial dislocations on(111)γplanes without a change in atomic spacing.The formation of anα'inclusion in a singleε-band is achieved by a continuous lattice distortion,accompanied by the formation of a tran-sition zone ofα'and the expansion of the average atomic spacings due to dislocation shuffling.Asα'grows further intoγ,the orientation relationship(OR)of theα'changes by lattice bending.This pro-cess follows the Bogers-Burgers-Olson-Cohen model despite it not occurring on intersecting shear bands.Stacking faults and twins can also serve as nucleation sites forα'at 173 K.We also found that direct transformation of γ→α'occurs by the glide of √6aγ[11(2)]/12 dislocations on every(111)γplane with misfit dislocations.Overall,this study provides,for the first time,insights into the atomic-scale mech-anisms of various two-step and one-step martensitic transformations induced by cryogenic deformation and corresponding local strain,enhancing our understanding of the role of martensitic transformation under ultra-cryogenic-temperature deformation in controlling the properties.
文摘Objective To evaluate the prevalence,awareness,treatment and control rate of hypertension among elder population in China.Methods Data form a cross-sectional stratified multistage random sampling survey conducted from 2012 to 2015 were used to analyzed.Finally,a total of 134,397 participants aged≥60 years were enrolled in our study.Hypertension was defined as systolic BP≥140 mmHg,and/or diastolic BP≥90 mmHg,and/or use of antihypertensive medicine within 2 weeks.Among participants with hypertension,control rate of hypertension was defined as the participant presenting as hypertensive,but with a systolic BP measure less than 140 mm Hg and diastolic BP measure less than 90 mm Hg.
基金supported in part by the National Natural Science Foundation of China(No.U19A2064)the Hunan Provincial Science and Technology Program(No.2019CB1007)+1 种基金the Fundamental Research Funds for the Central Universities,CSU(No.2282019SYLB004)the Fundamental Research Funds for the Central Universities of Central South University(No.2020zzts593)。
文摘Recently,the emergence of single-cell RNA-sequencing(scRNA-seq)technology makes it possible to solve biological problems at the single-cell resolution.One of the critical steps in cellular heterogeneity analysis is the cell type identification.Diverse scRNA-seq clustering methods have been proposed to partition cells into clusters.Among all the methods,hierarchical clustering and spectral clustering are the most popular approaches in the downstream clustering analysis with different preprocessing strategies such as similarity learning,dropout imputation,and dimensionality reduction.In this study,we carry out a comprehensive analysis by combining different strategies with these two categories of clustering methods on scRNA-seq datasets under different biological conditions.The analysis results show that the methods with spectral clustering tend to perform better on datasets with continuous shapes in two-dimension,while those with hierarchical clustering achieve better results on datasets with obvious boundaries between clusters in two-dimension.Motivated by this finding,a new strategy,called QRS,is developed to quantitatively evaluate the latent representative shape of a dataset to distinguish whether it has clear boundaries or not.Finally,a data-driven clustering recommendation method,called DDCR,is proposed to recommend hierarchical clustering or spectral clustering for scRNA-seq data.We perform DDCR on two typical single cell clustering methods,SC3 and RAFSIL,and the results show that DDCR recommends a more suitable downstream clustering method for different scRNA-seq datasets and obtains more robust and accurate results.
