Major problems of agricultural technological innovation in China were summarized as below: first,poor agricultural science and technology system; second,deficient technological promotion system; third,shortage of agri...Major problems of agricultural technological innovation in China were summarized as below: first,poor agricultural science and technology system; second,deficient technological promotion system; third,shortage of agricultural professionals; fourth,serious shortage of science and technology input. In view of these problems,the following suggestions were given to improve the innovation of agricultural technology in China. ( 1) Restructuring agricultural research institutes,establishing cooperative innovation centers,improving agricultural technological innovation system; ( 2) Specifying the direction of research projects,improving scientific research level of technicians,so as to improve the agricultural technological innovation capacity; ( 3) Improving promotion and service stations in towns,organizing technological service teams of agricultural universities and colleges,establishing agricultural technological promotion systems; ( 4) Increasing input in agricultural technological innovation by attracting government input,enterprise investment and other financial support; ( 5) Cultivating more talents of agricultural technology,training leading agricultural technicians,grassroots agricultural service staff and practical talents.展开更多
ZiYuan3-03(ZY3-03)satellite was launched on July 25,2020,equipped with China’s second-generation laser altimeter for earth observation.In order to preliminarily evaluate the in-orbit performance of the ZY3-03 laser a...ZiYuan3-03(ZY3-03)satellite was launched on July 25,2020,equipped with China’s second-generation laser altimeter for earth observation.In order to preliminarily evaluate the in-orbit performance of the ZY3-03 laser altimeter,the pointing bias calibration based on terrain matching method was adopted.Three tracks of laser data were employed for the ZY3-03 laser altimeter calibration test.Three groups of pointing parameters were obtained respectively,and the mean value of pointing is considered as the optimal calibration result.After calibration,ZY3-03 laser pointing accuracy is greatly improved by the method,and its pointing accuracy is approximately 12.7 arcsec.The first-track laser data on the Black Sea surface is used to evaluate the relative elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration,which is improved from 0.33 m to 0.19 m after calibration.Meanwhile,the absolute elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration is evaluated by the Ground Control Points(GCPs)measured by RTK(Real-Time Kinematic),which is better than 0.5 m in the flat terrain.展开更多
Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized ...Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.展开更多
Meibomian gland dysfunction(MGD)manifests through two main clinical presentations,characterized by the meibomian gland(MG)ductal obstruction or acinar dropout.While previous research has predominantly associated MGD p...Meibomian gland dysfunction(MGD)manifests through two main clinical presentations,characterized by the meibomian gland(MG)ductal obstruction or acinar dropout.While previous research has predominantly associated MGD pathogenesis with hyperkeratinization-related MG ductal obstruction and subsequent acinar atrophy,recent cases have shown significant functional acinar loss in the absence of apparent ductal keratinization or blockage.The deterioration of either MG obstruction or dropout exacerbates the condition of the other,suggesting an independent yet interconnected relationship that perpetuates the vicious cycle of MGD.Understanding the distinct pathological features of MG obstruction and dropout is crucial for delineating their etiology and identifying targeted therapeutic strategies.This review explores the nuanced interrelations of MG obstruction and dropout,elucidating potential pathological mechanisms to establish a foundation for early MGD diagnosis and intervention.展开更多
The therapeutic efficacy of metformin in prostate cancer(PCa)appears uncertain based on various clinical trials.Metformin treatment failure may be attributed to the high frequency of transcriptional dysregulation,whic...The therapeutic efficacy of metformin in prostate cancer(PCa)appears uncertain based on various clinical trials.Metformin treatment failure may be attributed to the high frequency of transcriptional dysregulation,which leads to drug resistance.However,the underlying mechanism is still unclear.In this study,we found evidences that metformin resistance in PCa cells may be linked to cell cycle reactivation.Super-enhancers(SEs),crucial regulatory elements,have been shown to be associated with drug resistance in various cancers.Our analysis of SEs in metformin-resistant(MetR)PCa cells revealed a correlation with Prostaglandin Reductase 1(PTGR1)expression,which was identified as significantly increased in a cluster of cells with metformin resistance through single-cell transcriptome sequencing.Our functional experiments showed that PTGR1 overexpression accelerated cell cycle progression by promoting progression from the G0/G1 to the S and G2/M phases,resulting in reduced sensitivity to metformin.Additionally,we identified key transcription factors that significantly increase PTGR1 expression,such as SRF and RUNX3,providing potential new targets to address metformin resistance in PCa.In conclusion,our study sheds new light on the cellular mechanism underlying metformin resistance and the regulation of the SE-TFs-PTGR1 axis,offering potential avenues to enhance metformin’s therapeutic efficacy in PCa.展开更多
After being launched into orbit,the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch,environmental changes,and thermal ...After being launched into orbit,the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch,environmental changes,and thermal effects during long-term operation,which guarantees the accuracy of measurement data.In this study,a satellite laser geometric calibration method combining infrared detectors and corner-cube retroreflectors(CCRs)is proposed.First,a CCR-based laser ranging error calibration method was established,and then a laser pointing error calibration model was derived based on a single infrared detector array.Taking GaoFen-7(GF-7)satellite laser beam 2 as the experimental object,laser geometric calibration was realized using an infrared detector and CCR-measured data.Then,the accuracy of the proposed method was compared with that of other calibration methods,the CMLID and the CMSPR.The results show that the accuracy of the proposed calibration method is equivalent to that of the CMLID and higher than that of the CMSPR.Among them,the accuracy of the laser pointing after calibration using the proposed method is better than 0.8 arcsec,and the elevation accuracy of the laser on flat,sloping,and mountainous terrains is better than 0.11 m,0.30 m,and 1.80 m,respectively.展开更多
A key focus recently has been on assessing therisk of a coordinated cyber-physical attack and minimizing the impact of a successful attack. Most of the cyberattackers will have limited system information and conventio...A key focus recently has been on assessing therisk of a coordinated cyber-physical attack and minimizing the impact of a successful attack. Most of the cyberattackers will have limited system information and conventional power grid N-1 security analysis cannot be extended to assess the risk. Centrality measures are widely used in the network science and an attacker with incomplete information can use it to identify power system vulnerabilities by defining the system as a complex network but without real-time system measurements. This paper presents a graph theory based centrality indices for vulnerability assessment of the power system due to various bus and branch contingencies using limited system information and provides a preliminary defense mechanism to prevent such an attack. Proposed work answers the fundamental question of possible attack scenarios by balancing risk(limited information with low risk to get caught orhigh risk attack to access more system information) and impact(identifying contingencies with maximal impact on system operation). Statistical comparisons are made between the graph theory measures compared to the corresponding DC power flow based N-X linear sensitivity measures. A unified N-X centrality based performance index is proposed and validated against the AC power flow based performance index by doing the real-time simulations of an N-3 attack scenario. Defensive mechanisms using topology-based performance indices are also presented.展开更多
The limited treatment options for advanced prostate cancer(PCa)lead to the urgent need to discover new anticancer drugs.Mannose,an isomer of glucose,has been reported to have an anticancer effect on various tumors.How...The limited treatment options for advanced prostate cancer(PCa)lead to the urgent need to discover new anticancer drugs.Mannose,an isomer of glucose,has been reported to have an anticancer effect on various tumors.However,the anticancer effect of mannose in PCa remains unclear.In this study,we demonstrated that mannose inhibits the proliferation and promotes the apoptosis of PCa cells in vitro,and mannose was observed to have an anticancer effect in mice without harming their health.Accumulation of intracellular mannose simultaneously decreased the mitochondrial membrane potential,increased mitochondrial and cellular reactive oxygen species(ROS)levels,and reduced adenosine triphosphate(ATP)production in PCa cells.Mannose treatment of PCa cells induced changes in mitochondrial morphology,caused dysregulated expression of the fission protein,such as fission,mitochondrial 1(FIS1),and enhanced the expression of proapoptotic factors,such as BCL2-associated X(Bax)and BCL2-antagonist/killer 1(Bak).Furthermore,lower expression of mannose phosphate isomerase(MPI),the key enzyme in mannose metabolism,indicated poorer prognosis in PCa patients,and downregulation of MPI expression in PCa cells enhanced the anticancer effect of mannose.This study reveals the anticancer effect of mannose in PCa and its clinical significance in PCa patients.展开更多
文摘Major problems of agricultural technological innovation in China were summarized as below: first,poor agricultural science and technology system; second,deficient technological promotion system; third,shortage of agricultural professionals; fourth,serious shortage of science and technology input. In view of these problems,the following suggestions were given to improve the innovation of agricultural technology in China. ( 1) Restructuring agricultural research institutes,establishing cooperative innovation centers,improving agricultural technological innovation system; ( 2) Specifying the direction of research projects,improving scientific research level of technicians,so as to improve the agricultural technological innovation capacity; ( 3) Improving promotion and service stations in towns,organizing technological service teams of agricultural universities and colleges,establishing agricultural technological promotion systems; ( 4) Increasing input in agricultural technological innovation by attracting government input,enterprise investment and other financial support; ( 5) Cultivating more talents of agricultural technology,training leading agricultural technicians,grassroots agricultural service staff and practical talents.
基金Research and Development of Forest Resources Dynamic Monitoring and Forest Volume Estimation with LiDAR Data(No.2020YFE0200800)High Resolution Remote Sensing,Surveying and Mapping Application Program(No.42-Y30B04-9001-19/21)+4 种基金Active and Passive Composite Mapping and Application Technology with Visible,Infrared and Laser Sensors(No.D040106)Multi-beam Terrain Detection Laser and Its Application Technology(No.D040105)National Natural Science Foundation of China(Nos.41571440,41771360,41971426)Class B Project of Beijing Science and Technology Association Jinqiao Project Seed Fund(No.ZZ19013)Innovative Youth Talents Program,MNR(No.12110600000018003930)。
文摘ZiYuan3-03(ZY3-03)satellite was launched on July 25,2020,equipped with China’s second-generation laser altimeter for earth observation.In order to preliminarily evaluate the in-orbit performance of the ZY3-03 laser altimeter,the pointing bias calibration based on terrain matching method was adopted.Three tracks of laser data were employed for the ZY3-03 laser altimeter calibration test.Three groups of pointing parameters were obtained respectively,and the mean value of pointing is considered as the optimal calibration result.After calibration,ZY3-03 laser pointing accuracy is greatly improved by the method,and its pointing accuracy is approximately 12.7 arcsec.The first-track laser data on the Black Sea surface is used to evaluate the relative elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration,which is improved from 0.33 m to 0.19 m after calibration.Meanwhile,the absolute elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration is evaluated by the Ground Control Points(GCPs)measured by RTK(Real-Time Kinematic),which is better than 0.5 m in the flat terrain.
基金the financial support by the National Natural Science Foundation of China(Nos.22301107,52373057)the Nature Science Foundation of Jiangsu Province(No.BK20200610)+1 种基金the Fundamental Research Funds for the Central Universities(No.JUSRP122021)Jiangsu Province"Innovation and Entrepreneurship Doctor"Talent Plan(No.JSSCBS20221053)also provided support。
文摘Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.
基金supported by the National Natural Science Foundation of China(82371021,82201142)the Science Foundation of Guangdong Province(2023A1515012336,2023A1515010091,2023A1515030238).
文摘Meibomian gland dysfunction(MGD)manifests through two main clinical presentations,characterized by the meibomian gland(MG)ductal obstruction or acinar dropout.While previous research has predominantly associated MGD pathogenesis with hyperkeratinization-related MG ductal obstruction and subsequent acinar atrophy,recent cases have shown significant functional acinar loss in the absence of apparent ductal keratinization or blockage.The deterioration of either MG obstruction or dropout exacerbates the condition of the other,suggesting an independent yet interconnected relationship that perpetuates the vicious cycle of MGD.Understanding the distinct pathological features of MG obstruction and dropout is crucial for delineating their etiology and identifying targeted therapeutic strategies.This review explores the nuanced interrelations of MG obstruction and dropout,elucidating potential pathological mechanisms to establish a foundation for early MGD diagnosis and intervention.
基金This study was supported by the National Natural Science Foundation of China(82072813,82203557,82103358)The Science and Technology Development Fund,Macao SAR(File no.0031/2021/A,0090/2022/A)+1 种基金GuangDong Basic and Applied Basic Research Foundation(2020A1515110792,2022A1515010342,2020A1515110640,2020A1515011290)Guangzhou Municipal Science and Technology Project(202201010053).We thank Mr.Yuanqi Feng for bioinformatic support and discussion,Mr.Zuqing Deng for technical assistance and discussion.
文摘The therapeutic efficacy of metformin in prostate cancer(PCa)appears uncertain based on various clinical trials.Metformin treatment failure may be attributed to the high frequency of transcriptional dysregulation,which leads to drug resistance.However,the underlying mechanism is still unclear.In this study,we found evidences that metformin resistance in PCa cells may be linked to cell cycle reactivation.Super-enhancers(SEs),crucial regulatory elements,have been shown to be associated with drug resistance in various cancers.Our analysis of SEs in metformin-resistant(MetR)PCa cells revealed a correlation with Prostaglandin Reductase 1(PTGR1)expression,which was identified as significantly increased in a cluster of cells with metformin resistance through single-cell transcriptome sequencing.Our functional experiments showed that PTGR1 overexpression accelerated cell cycle progression by promoting progression from the G0/G1 to the S and G2/M phases,resulting in reduced sensitivity to metformin.Additionally,we identified key transcription factors that significantly increase PTGR1 expression,such as SRF and RUNX3,providing potential new targets to address metformin resistance in PCa.In conclusion,our study sheds new light on the cellular mechanism underlying metformin resistance and the regulation of the SE-TFs-PTGR1 axis,offering potential avenues to enhance metformin’s therapeutic efficacy in PCa.
基金supported by National Key Research and Development Program of China:[Grant Number 2020YFE0200800]National Natural Science Foundation of China:[Grant Number 41971426]+1 种基金Special Funds for Creative Research:[Grant Number 2022C61540]Innovative Youth Talents Program,Ministry of Natural Resources of the People’s Republic of China:[Grant Number 12110600000018003930].
文摘After being launched into orbit,the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch,environmental changes,and thermal effects during long-term operation,which guarantees the accuracy of measurement data.In this study,a satellite laser geometric calibration method combining infrared detectors and corner-cube retroreflectors(CCRs)is proposed.First,a CCR-based laser ranging error calibration method was established,and then a laser pointing error calibration model was derived based on a single infrared detector array.Taking GaoFen-7(GF-7)satellite laser beam 2 as the experimental object,laser geometric calibration was realized using an infrared detector and CCR-measured data.Then,the accuracy of the proposed method was compared with that of other calibration methods,the CMLID and the CMSPR.The results show that the accuracy of the proposed calibration method is equivalent to that of the CMLID and higher than that of the CMSPR.Among them,the accuracy of the laser pointing after calibration using the proposed method is better than 0.8 arcsec,and the elevation accuracy of the laser on flat,sloping,and mountainous terrains is better than 0.11 m,0.30 m,and 1.80 m,respectively.
文摘A key focus recently has been on assessing therisk of a coordinated cyber-physical attack and minimizing the impact of a successful attack. Most of the cyberattackers will have limited system information and conventional power grid N-1 security analysis cannot be extended to assess the risk. Centrality measures are widely used in the network science and an attacker with incomplete information can use it to identify power system vulnerabilities by defining the system as a complex network but without real-time system measurements. This paper presents a graph theory based centrality indices for vulnerability assessment of the power system due to various bus and branch contingencies using limited system information and provides a preliminary defense mechanism to prevent such an attack. Proposed work answers the fundamental question of possible attack scenarios by balancing risk(limited information with low risk to get caught orhigh risk attack to access more system information) and impact(identifying contingencies with maximal impact on system operation). Statistical comparisons are made between the graph theory measures compared to the corresponding DC power flow based N-X linear sensitivity measures. A unified N-X centrality based performance index is proposed and validated against the AC power flow based performance index by doing the real-time simulations of an N-3 attack scenario. Defensive mechanisms using topology-based performance indices are also presented.
基金supported by grants from the National Natural Science Foundation of China(No.82072813)Natural Science Foundation of Guangdong Province(No.2020A1515010473 and No.2018A030313668)China Postdoctoral Science Foundation(No.2020M682666).
文摘The limited treatment options for advanced prostate cancer(PCa)lead to the urgent need to discover new anticancer drugs.Mannose,an isomer of glucose,has been reported to have an anticancer effect on various tumors.However,the anticancer effect of mannose in PCa remains unclear.In this study,we demonstrated that mannose inhibits the proliferation and promotes the apoptosis of PCa cells in vitro,and mannose was observed to have an anticancer effect in mice without harming their health.Accumulation of intracellular mannose simultaneously decreased the mitochondrial membrane potential,increased mitochondrial and cellular reactive oxygen species(ROS)levels,and reduced adenosine triphosphate(ATP)production in PCa cells.Mannose treatment of PCa cells induced changes in mitochondrial morphology,caused dysregulated expression of the fission protein,such as fission,mitochondrial 1(FIS1),and enhanced the expression of proapoptotic factors,such as BCL2-associated X(Bax)and BCL2-antagonist/killer 1(Bak).Furthermore,lower expression of mannose phosphate isomerase(MPI),the key enzyme in mannose metabolism,indicated poorer prognosis in PCa patients,and downregulation of MPI expression in PCa cells enhanced the anticancer effect of mannose.This study reveals the anticancer effect of mannose in PCa and its clinical significance in PCa patients.
