Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are i...Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems. A study of responses of soil APA to simulated N deposition was conducted in three succession forests of subtropical China. The three forests include a Masson pine (Pinus massoniana) forest (MPF)-pioneer community, a coniferous and broad-leaved mixed forest (MF)-transition community and a monsoon evergreen broad-leaved forest (MEBF)-climax community. Four N treatments were designed for MEBF: control (without N added), low-N (50 kg N ha-1 year-1), and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1), and only three N treatments (i.e., control, low-N, medium-N) were established for MPF and MF. Results showed that soil APA was highest in MEBF, followed by MPF and MF. Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N treatments. However, soil APA in MEBF exhibited negative responses to high N additions, indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem. Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.展开更多
The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to meas...The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to measure the separate electron and positron spectra,as well as the positron fraction.In this study,the Earth's magnetic field is used to distinguish CR electrons and positrons,as the DAMPE detector does not carry an onboard magnet.The energy for the measurements ranges from 10 to 20 GeV,which is currently limited at high energy by the zenith-pointing orientation of DAMPE.The results are consistent with previous measurements based on the magnetic spectrometer by AMS-02 and PAMELA,whereas the results of Fermi-LAT appear to be systematically shifted to larger values.展开更多
Various optical signals are popularly harnessed to realize anticounterfeiting,encryption,and photoluminescence(PL)-based sensing.However,most phosphors can only achieve single PL output under a fixed excitation,thus s...Various optical signals are popularly harnessed to realize anticounterfeiting,encryption,and photoluminescence(PL)-based sensing.However,most phosphors can only achieve single PL output under a fixed excitation,thus simultaneous attainment of multimodal PL behaviors remains an imperative pursuit.Herein,a highly integrated multimodal photon-,temperature-,and mechanically responsive Sr_(2)Ga_(2)SiO_(7):Zn^(2+)/Er^(3+)/Pr^(3+)(SGS:Zn/Er/Pr)is designed/synthesized via a facile solid-state reaction,endowing tunable down/up-converted(DC/UC)PL,mechanoluminescence(ML),and long-persistent PL(LPL)owing to the synergistic effects of self-activated and dopant-induced electronic transitions.Vöserves as both an emitter and a trap center for the self-(L)PL located at∼468 nm underλ_(ex)=267 nm.These behaviors are further optimized by adjusting the content of Vöand by forming a bridge(Znï)between trap levels upon Zn^(2+)incorporation.The excitation and Zn^(2+)content-dependent PL can be modified from blue to cyan via conflating dual self-PL from the^(4)T_(1)→^(4)A_(1)transition of Ga^(3+)at∼402 nm and Vö.The green DC/red UC PL from Er^(3+)is observed underλ_(ex)=357 and 980 nm,respectively.Nonequivalent substitution of Pr^(3+)at the Sr^(2+)site and the incorporation of Zn^(2+)can adjust the charge transfer band energy level position and optimize the trap distribution,achieving long-term storage and highly repeatable/efficient LPL/ML generation.Based on abundant PL multimodes,the single-phased SGS:Zn/Er/Pr shows promising applications in sophisticated anticounterfeiting and latent fingerprint detection.Concurrently,owing to the coupled energy levels^(2)H_(11/2)/^(4)S_(3/2)of Er^(3+)and the pressure-dependent ML of Pr^(3+),the SGS:Zn/Er/Pr is also suitably applied as a temperature/stress sensing agent.展开更多
With the increasing application of steroid drugs as therapeutics,the demand for steroid drugs is increasing.In recent years,biological synthesis has become the standard approach to produce steroid intermediates,while ...With the increasing application of steroid drugs as therapeutics,the demand for steroid drugs is increasing.In recent years,biological synthesis has become the standard approach to produce steroid intermediates,while this method still faces some problems such as unclear metabolic pathway and low yield.Mycobacterium sp.LY-1 can convert phytosterols into 9α-hydroxyandrost-4-ene-3,17-dione(9α-OH-AD)which is a key intermediate for the synthesis of steroid drugs with long effective time and significant pharmacological activity.In this work,the whole-genome sequence of the Mycobacterium sp.LY-1 was analyzed,and the side-chain degradation pathway of phytosterols in Mycobacterium sp.LY-1 was proposed.Meanwhile,the related key enzymes of phytosterol metabolism were identified through qRT-PCR.Through overexpressing the key enzymes including KshA2,KshB,and HsdB,the yield of 9α-OH-AD increased by 12.7%compared to that of the control.Furthermore,by optimizing the medium and culture conditions,the yield of 9α-OH-AD reached 50.4%.The maxi-mum yield was 30.7%higher than that of the original strain.The results are of significance for the industrial production of 9α-OH-AD using metabolic engineering methods.展开更多
Boldenone is a protein-assimilating androgen steroid that can promote protein synthesis,support nitrogen storage,and enhance renal erythropoietin release.The industrial production of boldenone mainly relies on chemica...Boldenone is a protein-assimilating androgen steroid that can promote protein synthesis,support nitrogen storage,and enhance renal erythropoietin release.The industrial production of boldenone mainly relies on chemical synthesis,which has various problems,such as a complex conversion process,excessive byproducts,and serious environmental pollution.There-fore,it is of great significance to explore a new biosynthetic route.Recently,the enzymatic synthesis of steroid compounds has been performed more frequently than in the past.In this work,boldenone was produced from androstenedione(AD)in two steps by a dual-enzyme cascade of 17β-hydroxysteroid dehydrogenase(17β-HSD)and 3-sterone-Δ^(1)-dehydrogenase(KstD).The conversion efficiency of three isoenzymes of 17β-HSD from Mycobacterium sp.LY-1 for substrate AD was first analyzed.After that,the 17β-HSD2 with high selectivity and specificity for AD was screened and co-expressed with KstD3 in Escherichia coli BL21 to construct a dual-enzyme catalytic system.The results showed that the synthesis of boldenone from AD could be achieved by constructing the dual-enzyme expression system of 17β-HSD and KstD,as we determined that the concentration of boldenone reached 24.3 mg/L.To further improve the synthesis efficiency of boldenone,the expression conditions of the dual-enzyme system were optimized,and the concentration of boldenone reached 31.9 mg/L.The explora-tion of this route will provide a foundation for the efficient enzymatic synthesis of boldenone.展开更多
基金the "Strategic Priority Research Program" of the Chinese Academy of Sciences (No.XDA05050208)the National Natural Science Foundation of China (Nos.31070439 and 40730102)the Knowledge Innovation Program of the Chinese Academy of Sciences (Nos.KSCX2-EW-Q-8 and KSCX2-EW-J-28)
文摘Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems. A study of responses of soil APA to simulated N deposition was conducted in three succession forests of subtropical China. The three forests include a Masson pine (Pinus massoniana) forest (MPF)-pioneer community, a coniferous and broad-leaved mixed forest (MF)-transition community and a monsoon evergreen broad-leaved forest (MEBF)-climax community. Four N treatments were designed for MEBF: control (without N added), low-N (50 kg N ha-1 year-1), and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1), and only three N treatments (i.e., control, low-N, medium-N) were established for MPF and MF. Results showed that soil APA was highest in MEBF, followed by MPF and MF. Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N treatments. However, soil APA in MEBF exhibited negative responses to high N additions, indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem. Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.
基金supported by the National Key Research and Development Program of China(No.2022YFF0503303)the National Natural Science Foundation of China(Nos.12220101003,12275266,12003076,12022503,12103094 and U2031149)+8 种基金Outstanding Youth Science Foundation of NSFC(No.12022503)the Project for Young Scientists in Basic Research of the Chinese Academy of Sciences(No.YSBR-061)the Strategic Priority Program on Space Science of Chinese Academy of Sciences(No.E02212A02S)the Youth Innovation Promotion Association of CAS(No.2021450)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220197)the New Cornerstone Science Foundation through the XPLORER PRIZEthe Program for Innovative Talents and Entrepreneur in Jiangsu.In Europesupported by the Swiss National Science Foundation(SNSF),Switzerland,the National Institute for Nuclear Physics(INFN),Italythe European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(No.851103).
文摘The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to measure the separate electron and positron spectra,as well as the positron fraction.In this study,the Earth's magnetic field is used to distinguish CR electrons and positrons,as the DAMPE detector does not carry an onboard magnet.The energy for the measurements ranges from 10 to 20 GeV,which is currently limited at high energy by the zenith-pointing orientation of DAMPE.The results are consistent with previous measurements based on the magnetic spectrometer by AMS-02 and PAMELA,whereas the results of Fermi-LAT appear to be systematically shifted to larger values.
基金supported by the Opening Foundations from the Key Laboratory of Testing and Tracing of Rare Earth Products for State Market Regulation(Grant No.:TTREP2022ZD03)the Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration(Wuhan University)(Grant No.:EMPI2023011)the 16th Graduate Innovation Fund from the Wuhan Institute of Technology(Grant No.:CX2024296).
文摘Various optical signals are popularly harnessed to realize anticounterfeiting,encryption,and photoluminescence(PL)-based sensing.However,most phosphors can only achieve single PL output under a fixed excitation,thus simultaneous attainment of multimodal PL behaviors remains an imperative pursuit.Herein,a highly integrated multimodal photon-,temperature-,and mechanically responsive Sr_(2)Ga_(2)SiO_(7):Zn^(2+)/Er^(3+)/Pr^(3+)(SGS:Zn/Er/Pr)is designed/synthesized via a facile solid-state reaction,endowing tunable down/up-converted(DC/UC)PL,mechanoluminescence(ML),and long-persistent PL(LPL)owing to the synergistic effects of self-activated and dopant-induced electronic transitions.Vöserves as both an emitter and a trap center for the self-(L)PL located at∼468 nm underλ_(ex)=267 nm.These behaviors are further optimized by adjusting the content of Vöand by forming a bridge(Znï)between trap levels upon Zn^(2+)incorporation.The excitation and Zn^(2+)content-dependent PL can be modified from blue to cyan via conflating dual self-PL from the^(4)T_(1)→^(4)A_(1)transition of Ga^(3+)at∼402 nm and Vö.The green DC/red UC PL from Er^(3+)is observed underλ_(ex)=357 and 980 nm,respectively.Nonequivalent substitution of Pr^(3+)at the Sr^(2+)site and the incorporation of Zn^(2+)can adjust the charge transfer band energy level position and optimize the trap distribution,achieving long-term storage and highly repeatable/efficient LPL/ML generation.Based on abundant PL multimodes,the single-phased SGS:Zn/Er/Pr shows promising applications in sophisticated anticounterfeiting and latent fingerprint detection.Concurrently,owing to the coupled energy levels^(2)H_(11/2)/^(4)S_(3/2)of Er^(3+)and the pressure-dependent ML of Pr^(3+),the SGS:Zn/Er/Pr is also suitably applied as a temperature/stress sensing agent.
基金supported by the National Key R&D Program of China(No.2019YFA0905300)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No.TSBICIPKJGG-001-14)+1 种基金the National Natural Science Foundation of China(No.22078126)Qing Lan Project in Jiangsu Province and Fundamental Research Funds for the Central Universities(JUSRP221025).
文摘With the increasing application of steroid drugs as therapeutics,the demand for steroid drugs is increasing.In recent years,biological synthesis has become the standard approach to produce steroid intermediates,while this method still faces some problems such as unclear metabolic pathway and low yield.Mycobacterium sp.LY-1 can convert phytosterols into 9α-hydroxyandrost-4-ene-3,17-dione(9α-OH-AD)which is a key intermediate for the synthesis of steroid drugs with long effective time and significant pharmacological activity.In this work,the whole-genome sequence of the Mycobacterium sp.LY-1 was analyzed,and the side-chain degradation pathway of phytosterols in Mycobacterium sp.LY-1 was proposed.Meanwhile,the related key enzymes of phytosterol metabolism were identified through qRT-PCR.Through overexpressing the key enzymes including KshA2,KshB,and HsdB,the yield of 9α-OH-AD increased by 12.7%compared to that of the control.Furthermore,by optimizing the medium and culture conditions,the yield of 9α-OH-AD reached 50.4%.The maxi-mum yield was 30.7%higher than that of the original strain.The results are of significance for the industrial production of 9α-OH-AD using metabolic engineering methods.
基金supported by National Key Research and Development Program of China(No.2019YFA0905300)the National Natural Science Foundation of China(No.22078126)+1 种基金Qing Lan Project in Jiangsu ProvinceFundamental Research Funds for Central Universities of China(No.JUSRP221025).
文摘Boldenone is a protein-assimilating androgen steroid that can promote protein synthesis,support nitrogen storage,and enhance renal erythropoietin release.The industrial production of boldenone mainly relies on chemical synthesis,which has various problems,such as a complex conversion process,excessive byproducts,and serious environmental pollution.There-fore,it is of great significance to explore a new biosynthetic route.Recently,the enzymatic synthesis of steroid compounds has been performed more frequently than in the past.In this work,boldenone was produced from androstenedione(AD)in two steps by a dual-enzyme cascade of 17β-hydroxysteroid dehydrogenase(17β-HSD)and 3-sterone-Δ^(1)-dehydrogenase(KstD).The conversion efficiency of three isoenzymes of 17β-HSD from Mycobacterium sp.LY-1 for substrate AD was first analyzed.After that,the 17β-HSD2 with high selectivity and specificity for AD was screened and co-expressed with KstD3 in Escherichia coli BL21 to construct a dual-enzyme catalytic system.The results showed that the synthesis of boldenone from AD could be achieved by constructing the dual-enzyme expression system of 17β-HSD and KstD,as we determined that the concentration of boldenone reached 24.3 mg/L.To further improve the synthesis efficiency of boldenone,the expression conditions of the dual-enzyme system were optimized,and the concentration of boldenone reached 31.9 mg/L.The explora-tion of this route will provide a foundation for the efficient enzymatic synthesis of boldenone.
