Application of slow-release fertilizer(SF)is a nutrient-management measure aimed at improving maize nutrient use and yield and saving labor cost.One-time application of SF at sowing usually results in nutrient deficie...Application of slow-release fertilizer(SF)is a nutrient-management measure aimed at improving maize nutrient use and yield and saving labor cost.One-time application of SF at sowing usually results in nutrient deficiency during the post-silking stage,owing to the long growth period of spring maize.This study was conducted to investigate the effects on spring maize of SF application stage(zero,three-,and six-leaf stages,designated as SF0,SF3,and SF6,respectively)on grain yield,total soil rhizosphere nitrogen(N)content,and root activity,in comparison with the conventional fertilization mode(CF,application of compound fertilizer at sowing time,and topdressing urea at six-leaf and tasseling stages)at the same fertilization level as the control.Compared with no fertilization(F0)and CF,SF increased grain number and weight.The maize cultivars Suyu 30(SY30)and Jiangyu 877(JY877)produced the highest grain yield and net return under SF6 treatment over the three years.SF6 increased enzymatic activities including oxidoreductase,hydrolase,transferase,and lyase in rhizosphere soil at silking(R1)and milking stages(R3).SF6 increased the total N contents of rhizosphere soil by 7.1%at R1 and 9.2%R3 stages compared with SF0.The activities of antioxidant enzymes in roots were increased under SF6 treatments at R1and R3.The mean root activities of SF0,SF3,and SF6 increased by 7.1%,12.8%,and 20.5%compared with CF at R1 and by 8.8%,13.0%,and 23.5%at R3.Delaying the application time of SF could increase grain yield by increasing total N content of rhizosphere soil,delaying root senescence,and increasing root activity at the late reproductive stage.Applying SF at the six-leaf stage is recommended as an effective fertilization strategy for the sustainable production of spring maize in southern China.展开更多
A high-yield and beam-stable neutron tube can be applied in many fields.It is of great significance to the optimal external magnetic field intensity of the cold-cathode Penning ion source(PIS)and precisely controls th...A high-yield and beam-stable neutron tube can be applied in many fields.It is of great significance to the optimal external magnetic field intensity of the cold-cathode Penning ion source(PIS)and precisely controls the movement of deuterium(D),tritium(T)ions and electrons in the source of the neutron tubes.A cold-cathode PIS is designed based on the solenoidal magnetic field to obtain better uniformity of the magnetic field and higher yield of the neutron tube.The degree of magnetic field uniformity among the magnetic block,double magnetic rings and solenoidal ion sources is compared using finite element simulation methods.Using drift diffusion approximation and a magnetic field coupling method,the plasma distribution of hydrogen and the relationship between plasma density and magnetic field intensity at 0.06 Pa pressure and a solenoid magnetic field are obtained.The results show that the solenoidal ion source has the most uniform magnetic field distribution.The optimum magnetic field strength of about 0.1 T is obtained in the ion source at an excitation voltage of 1 V.The maximum average number density of monatomic hydrogen ions(H+)is 1×108 m−3,and an ion-beam current of about 14.51μA is formed under the−5000 V extraction field.The study of the solenoidal magnetic field contributes to the understanding of the particle dynamics within the PIS and provides a reference for the further improvement of the source performance of the neutron tube in the future.展开更多
Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high ...Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high shielding effectiveness(SE),good flexibility and stability are highly desirable.Herein,an ultrathin flexible copper/graphene(Cu/Gr)nanolayered composite are prepared,which can reach the average EMI SE of 60.95 dB at 0.1–1.0 THz with a thickness of only 160 nm,indicating that more than 99.9999%of the THz wave power can be shielded.Furthermore,the Cu/Gr nanolayered composite also exhibits excellent oxidation resistance,with a 93.09%maintenance rate for EMI SE value after heating at 120℃for 3 h in air,far higher than that of the bare Cu film(62.15%).Besides,the Cu/Gr nanolayered composite exhibits good mechanical flexibility and flexural fatigue resistance.The EMI SE value of the Cu/Gr nanolayered composite shows a maintenance rate of 98.87%even after 1500 times bending cycles,obviously higher than that of multilayer Cu film(93.07%).These results demonstrate that the ultrathin flexible Cu/Gr nanolayered composites with excellent shielding performance and good stability have a broad application prospect in THz shielding for wearable devices and next generation mobile communication equipment.展开更多
Light modulates human brain function through its effect on circadian rhythms,which are related to several human behavioral and physiological processes.Functional near-infrared spectroscopy(fNIRS)is a noninvasive optic...Light modulates human brain function through its effect on circadian rhythms,which are related to several human behavioral and physiological processes.Functional near-infrared spectroscopy(fNIRS)is a noninvasive optical neuroimaging technique used for recording brain activation during task performance.This study aimed to investigate the effects of light on cognitive function,particularly in the prefrontal cortex using fNIRS.The effect of light on cognitive modulation was analyzed using the Stroop task,which was performed on 30 participants under three different light conditions(color temperature 4500 K,2500 K,and none).The behavioral results indicated that light conditions can easily and effectively modulate the performance of tasks based on the feedback,including the response time and accuracy.fNIRS showed hemodynamic changes in the bilateral dorsolateral prefrontal cortices,and the activated brain regions varied under different light conditions.Moreover,light may be regarded as a safe,effective,inexpensive,and accessible tool for modulating human cognitive function.展开更多
Transition metal oxides are regarded as an economical and efficient catalytic alternate for catalytic oxidation of volatile organic compounds(VOCs)emissions.The morphological decoration and the incorporation of extrin...Transition metal oxides are regarded as an economical and efficient catalytic alternate for catalytic oxidation of volatile organic compounds(VOCs)emissions.The morphological decoration and the incorporation of extrinsic metals were demonstrated to be effective strategies for achieving noticeable catalytic improvement.In this work,a novel Co-Ce composite oxides catalyst was obtained by the pyrolysis of ZIF-67 template with the impregnation of certain cerium cations(denoted as ZIF-CoCe).Compared with the reference Co-Ce composite oxides by the sol-gel(denoted as SG-CoCe)and physical mixing(denoted as MIX-CoCe)methods,ZIF-CoCe delivers significantly higher catalytic activity for vinyl chloride oxidation,which are demonstrated to be closely related with its superior redox capacity,more abundance of surface active Co^(3+)sites and adsorbed active oxygen species from oxygen vacancies.In addition,the unique cage-like morphological feature of the Co-based catalysts derived from ZIF-67 template plays a crucial function in kinetically facilitating the mass transfer of catalytic reaction and promoting the catalytic VC oxidation activity.With regard to in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis,enol and carboxylic acid species are identified to be the key organic intermediates during catalytic vinyl chloride oxidation.展开更多
Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regu...Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regulates the utilization of sugars for growth remains to be addressed.Here,we report that the sugar-inducible rice NAC transcription factor OsNAC23 directly represses the transcription of the Tre6P phosphatase gene TPP1 to simultaneously elevate Tre6P and repress trehalose levels,thus facilitating carbon partitioning from source to sink organs.Meanwhile,OsNAC23 and Tre6P suppress the transcription and enzyme activity of SnRK1a,a low-carbon sensor and antagonist of OsNAC23,to prevent the SnRK1a-mediated phosphorylation and degradation of OsNAC23.Thus,OsNAC23,Tre6P,and SnRK1a form a feed-forward loop to sense sugar and maintain sugar homeostasis by transporting sugars to sink organs.Importantly,plants over-expressing OsNAC23 exhibited an elevated photosynthetic rate,sugar transport,and sink organ size,which consistently increased rice yields by 13%–17%in three elite-variety backgrounds and two locations,suggesting that manipulation of OsNAC23 expression has great potential for rice improvement.Collectively,these findings enhance our understanding of Tre6P-mediated sugar signaling and homeostasis,and provide a new strategy for genetic improvement of rice and possibly also other crops.展开更多
Uncovering the functionally essential variations related to tumorigenesis and tumor progression from cancer genomics data is still challenging due to the genetic diversity among patients,and extensive inter-and intra-...Uncovering the functionally essential variations related to tumorigenesis and tumor progression from cancer genomics data is still challenging due to the genetic diversity among patients,and extensive inter-and intra-tumoral heterogeneity at different levels of gene expression regulation,including but not limited to the genomic, epigenomic, and transcriptional levels. To minimize the impact of germline genetic heterogeneities, in this study, we establish multiple primary cultures from the primary and recurrent tumors of a single patient with hepatocellular carcinoma(HCC). Multiomics sequencing was performed for these cultures that encompass the diversity of tumor cells from the same patient. Variations in the genome sequence, epigenetic modification, and gene expression are used to infer the phylogenetic relationships of these cell cultures. We find the discrepancy among the relationships revealed by single nucleotide variations(SNVs) and transcriptional/epigenomic profiles from the cell cultures. We fail to find overlap between sample-specific mutated genes and differentially expressed genes(DEGs), suggesting that most of the heterogeneous SNVs among tumor stages or lineages of the patient are functionally insignificant. Moreover, copy number alterations(CNAs) and DNA methylation variation within gene bodies, rather than promoters, are significantly correlated with gene expression variability among these cell cultures. Pathway analysis of CNA/DNA methylation-related genes indicates that a single cell clone from the recurrent tumor exhibits distinct cellular characteristics and tumorigenicity, and such an observation is further confirmed by cellular experiments both in vitro and in vivo. Our systematic analysis reveals that CNAs and epigenomic changes, rather than SNVs, are more likely to contribute to the phenotypic diversity among subpopulations in the tumor. These findings suggest that new therapeutic strategies targeting gene dosage and epigenetic modification should be considered in personalized cancer medicine. This culture model may be applied to the further identification of plausible determinants of cancer metastasis and relapse.展开更多
基金the financial support of the National Key Research and Development Program of China(2016YFD0300109)National Natural Science Foundation of China(32101828,32071958)+3 种基金Natural Science Foundation of Jiangsu Province(BK20200952)the Open Project Program of Joint International Research Laboratory of Agriculture and Agri-Product Safety(JILAR-KF202010)the Jiangsu Agricultural Industry Technology System of China(JATS[2020]444)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Application of slow-release fertilizer(SF)is a nutrient-management measure aimed at improving maize nutrient use and yield and saving labor cost.One-time application of SF at sowing usually results in nutrient deficiency during the post-silking stage,owing to the long growth period of spring maize.This study was conducted to investigate the effects on spring maize of SF application stage(zero,three-,and six-leaf stages,designated as SF0,SF3,and SF6,respectively)on grain yield,total soil rhizosphere nitrogen(N)content,and root activity,in comparison with the conventional fertilization mode(CF,application of compound fertilizer at sowing time,and topdressing urea at six-leaf and tasseling stages)at the same fertilization level as the control.Compared with no fertilization(F0)and CF,SF increased grain number and weight.The maize cultivars Suyu 30(SY30)and Jiangyu 877(JY877)produced the highest grain yield and net return under SF6 treatment over the three years.SF6 increased enzymatic activities including oxidoreductase,hydrolase,transferase,and lyase in rhizosphere soil at silking(R1)and milking stages(R3).SF6 increased the total N contents of rhizosphere soil by 7.1%at R1 and 9.2%R3 stages compared with SF0.The activities of antioxidant enzymes in roots were increased under SF6 treatments at R1and R3.The mean root activities of SF0,SF3,and SF6 increased by 7.1%,12.8%,and 20.5%compared with CF at R1 and by 8.8%,13.0%,and 23.5%at R3.Delaying the application time of SF could increase grain yield by increasing total N content of rhizosphere soil,delaying root senescence,and increasing root activity at the late reproductive stage.Applying SF at the six-leaf stage is recommended as an effective fertilization strategy for the sustainable production of spring maize in southern China.
基金supported by the China Jilin Province Science and Technology Development Project (No. 20190303101SF)the Sichuan Provincial Higher Education Key Laboratory Criminal Investigation Project-Criminal Science and Technology Laboratory (Sichuan Police College) (No. 2018YB04)+1 种基金Shanghai Jiao Tong Universitythe China Institute of Atomic Energy for their strong support
文摘A high-yield and beam-stable neutron tube can be applied in many fields.It is of great significance to the optimal external magnetic field intensity of the cold-cathode Penning ion source(PIS)and precisely controls the movement of deuterium(D),tritium(T)ions and electrons in the source of the neutron tubes.A cold-cathode PIS is designed based on the solenoidal magnetic field to obtain better uniformity of the magnetic field and higher yield of the neutron tube.The degree of magnetic field uniformity among the magnetic block,double magnetic rings and solenoidal ion sources is compared using finite element simulation methods.Using drift diffusion approximation and a magnetic field coupling method,the plasma distribution of hydrogen and the relationship between plasma density and magnetic field intensity at 0.06 Pa pressure and a solenoid magnetic field are obtained.The results show that the solenoidal ion source has the most uniform magnetic field distribution.The optimum magnetic field strength of about 0.1 T is obtained in the ion source at an excitation voltage of 1 V.The maximum average number density of monatomic hydrogen ions(H+)is 1×108 m−3,and an ion-beam current of about 14.51μA is formed under the−5000 V extraction field.The study of the solenoidal magnetic field contributes to the understanding of the particle dynamics within the PIS and provides a reference for the further improvement of the source performance of the neutron tube in the future.
基金supported financially by the Foundation of Ministry of Science and Technology of China(No.2016YFA0200200)the National Natural Science Foundation of China(Nos.21875114,51373078 and 51422304)111 Project(No.B18030)。
文摘Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high shielding effectiveness(SE),good flexibility and stability are highly desirable.Herein,an ultrathin flexible copper/graphene(Cu/Gr)nanolayered composite are prepared,which can reach the average EMI SE of 60.95 dB at 0.1–1.0 THz with a thickness of only 160 nm,indicating that more than 99.9999%of the THz wave power can be shielded.Furthermore,the Cu/Gr nanolayered composite also exhibits excellent oxidation resistance,with a 93.09%maintenance rate for EMI SE value after heating at 120℃for 3 h in air,far higher than that of the bare Cu film(62.15%).Besides,the Cu/Gr nanolayered composite exhibits good mechanical flexibility and flexural fatigue resistance.The EMI SE value of the Cu/Gr nanolayered composite shows a maintenance rate of 98.87%even after 1500 times bending cycles,obviously higher than that of multilayer Cu film(93.07%).These results demonstrate that the ultrathin flexible Cu/Gr nanolayered composites with excellent shielding performance and good stability have a broad application prospect in THz shielding for wearable devices and next generation mobile communication equipment.
基金the financial support of the National Key R&D Program of China(Grant No.2017YFE0112000)the Shanghai Municipal Science and Technology Major Project(Grant No.2017SHZDZX01).
文摘Light modulates human brain function through its effect on circadian rhythms,which are related to several human behavioral and physiological processes.Functional near-infrared spectroscopy(fNIRS)is a noninvasive optical neuroimaging technique used for recording brain activation during task performance.This study aimed to investigate the effects of light on cognitive function,particularly in the prefrontal cortex using fNIRS.The effect of light on cognitive modulation was analyzed using the Stroop task,which was performed on 30 participants under three different light conditions(color temperature 4500 K,2500 K,and none).The behavioral results indicated that light conditions can easily and effectively modulate the performance of tasks based on the feedback,including the response time and accuracy.fNIRS showed hemodynamic changes in the bilateral dorsolateral prefrontal cortices,and the activated brain regions varied under different light conditions.Moreover,light may be regarded as a safe,effective,inexpensive,and accessible tool for modulating human cognitive function.
基金Project supported by the National Natural Science Foundation of China(22076088,21607163).
文摘Transition metal oxides are regarded as an economical and efficient catalytic alternate for catalytic oxidation of volatile organic compounds(VOCs)emissions.The morphological decoration and the incorporation of extrinsic metals were demonstrated to be effective strategies for achieving noticeable catalytic improvement.In this work,a novel Co-Ce composite oxides catalyst was obtained by the pyrolysis of ZIF-67 template with the impregnation of certain cerium cations(denoted as ZIF-CoCe).Compared with the reference Co-Ce composite oxides by the sol-gel(denoted as SG-CoCe)and physical mixing(denoted as MIX-CoCe)methods,ZIF-CoCe delivers significantly higher catalytic activity for vinyl chloride oxidation,which are demonstrated to be closely related with its superior redox capacity,more abundance of surface active Co^(3+)sites and adsorbed active oxygen species from oxygen vacancies.In addition,the unique cage-like morphological feature of the Co-based catalysts derived from ZIF-67 template plays a crucial function in kinetically facilitating the mass transfer of catalytic reaction and promoting the catalytic VC oxidation activity.With regard to in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis,enol and carboxylic acid species are identified to be the key organic intermediates during catalytic vinyl chloride oxidation.
基金supported by National Key R&D Program of China(2020YFE0202300)CNRRI Key Research and Development Project(CNRRI-2020-01)+1 种基金National Natural Science Foundation of China(Grant grant no.32071986 and 31871229)ASTIP program of CAAS,China.All the authors declare no conflicts of interests in this paper.
文摘Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regulates the utilization of sugars for growth remains to be addressed.Here,we report that the sugar-inducible rice NAC transcription factor OsNAC23 directly represses the transcription of the Tre6P phosphatase gene TPP1 to simultaneously elevate Tre6P and repress trehalose levels,thus facilitating carbon partitioning from source to sink organs.Meanwhile,OsNAC23 and Tre6P suppress the transcription and enzyme activity of SnRK1a,a low-carbon sensor and antagonist of OsNAC23,to prevent the SnRK1a-mediated phosphorylation and degradation of OsNAC23.Thus,OsNAC23,Tre6P,and SnRK1a form a feed-forward loop to sense sugar and maintain sugar homeostasis by transporting sugars to sink organs.Importantly,plants over-expressing OsNAC23 exhibited an elevated photosynthetic rate,sugar transport,and sink organ size,which consistently increased rice yields by 13%–17%in three elite-variety backgrounds and two locations,suggesting that manipulation of OsNAC23 expression has great potential for rice improvement.Collectively,these findings enhance our understanding of Tre6P-mediated sugar signaling and homeostasis,and provide a new strategy for genetic improvement of rice and possibly also other crops.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB13000000)the National Natural Science Foundation of China (Grant Nos. 91531305, 31771416, 81373422, 31301036, and 31801094)National Key Basic Research Program of China (Grant No. 2014CB542006).
文摘Uncovering the functionally essential variations related to tumorigenesis and tumor progression from cancer genomics data is still challenging due to the genetic diversity among patients,and extensive inter-and intra-tumoral heterogeneity at different levels of gene expression regulation,including but not limited to the genomic, epigenomic, and transcriptional levels. To minimize the impact of germline genetic heterogeneities, in this study, we establish multiple primary cultures from the primary and recurrent tumors of a single patient with hepatocellular carcinoma(HCC). Multiomics sequencing was performed for these cultures that encompass the diversity of tumor cells from the same patient. Variations in the genome sequence, epigenetic modification, and gene expression are used to infer the phylogenetic relationships of these cell cultures. We find the discrepancy among the relationships revealed by single nucleotide variations(SNVs) and transcriptional/epigenomic profiles from the cell cultures. We fail to find overlap between sample-specific mutated genes and differentially expressed genes(DEGs), suggesting that most of the heterogeneous SNVs among tumor stages or lineages of the patient are functionally insignificant. Moreover, copy number alterations(CNAs) and DNA methylation variation within gene bodies, rather than promoters, are significantly correlated with gene expression variability among these cell cultures. Pathway analysis of CNA/DNA methylation-related genes indicates that a single cell clone from the recurrent tumor exhibits distinct cellular characteristics and tumorigenicity, and such an observation is further confirmed by cellular experiments both in vitro and in vivo. Our systematic analysis reveals that CNAs and epigenomic changes, rather than SNVs, are more likely to contribute to the phenotypic diversity among subpopulations in the tumor. These findings suggest that new therapeutic strategies targeting gene dosage and epigenetic modification should be considered in personalized cancer medicine. This culture model may be applied to the further identification of plausible determinants of cancer metastasis and relapse.
基金supported by the National Natural Science Foundation of China(91731301 and U1902201)the Ministry of Science and Technology of the People’s Republic of China(2020YFC0847000)the Light of West China Program of the Chinese Academy of Sciences.