As a potential endocrine-disrupting chemical,bisphenol F(BPF)may cause nonalcoholic fatty liver disease(NAFLD)-like changes,but the mechanisms under its pathogenesis as well as the intervention strategies remain uncle...As a potential endocrine-disrupting chemical,bisphenol F(BPF)may cause nonalcoholic fatty liver disease(NAFLD)-like changes,but the mechanisms under its pathogenesis as well as the intervention strategies remain unclear.Using the electron microscopy technology,along with LipidTOX Deep Red neutral and Bodipy 493/503 staining assays,we observed that BPF treatment elicited a striking accumulation of lipid droplets in HepG2 cells,accompanied by an increased total level of triglycerides.At the molecular level,the lipogenesis-associated mRNAs and proteins,including acetyl-CoA carboxylase,fatty acid synthase,stearoyl-CoA desaturase-1,peroxisome proliferator-activated receptor gamma,and CCAAT-enhancer-binding proteins,increased significantly via the AMP-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR)signaling regulation in both in vitro and in vivo studies.Furthermore,the immunofluorescence results also showed the robust lipogenesis induced by BPF,evident in its ability to promote the translocation of sterol regulatory element-binding protein-1c from the cytoplasm to the nuclei.To investigate the intervention strategies for BPF-induced NAFLD-like changes,we demonstrated that bellidifolin,isolated and purified from Swertia chirayita,significantly attenuated BPF-induced lipid droplet deposition in HepG2 cells and NAFLD-like changes in mice by blocking the expression of lipogenesis-associated proteins.Therefore,the present study elucidates the mechanisms underlying the BPF-induced lipid accumulation in HepG2 cells,while also highlighting the potential of bellidifolin to mitigate BPF-induced NAFLD-like changes.展开更多
For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in...For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in comparison with that of an AC power grid. The Jacobian matrix used in the power-flow calculation was deduced through methods such as Newton–Laphson iteration and Taylor series expansion. Further, the operation effect of powerflow calculation on a true bipolar VSC-HVDC power grid was analyzed briefly. The elements of the Jacobian matrix corresponding to VSC were studied under the mode of droop control and the control strategy of VSC-HVDC power grid was analyzed in detail. The power-flow calculation model for VSC-HVDC power grid of the master–slave control mode was simplified using the PQ decomposition method of the power-flow calculation of an AC power grid. Moreover, a four-terminal model of the Zhangbei VSC-HVDC demonstration project was established and tested on MATLAB. The simulation results under two kinds of operating conditions were analyzed and compared to the results of BPA; the deviation between the power-flow results was studied. The results show that the proposed calculation method can provide a feasible support for calculating the power flow in VSC-HVDC grids.展开更多
Current studies on cable harness layouts have mainly focused on cable harness route planning.However,the topological structure of a cable harness is also extremely complex,and the branch structure of the cable harness...Current studies on cable harness layouts have mainly focused on cable harness route planning.However,the topological structure of a cable harness is also extremely complex,and the branch structure of the cable harness can affect the route of the cable harness layout.The topological structure design of the cable harness is a key to such a layout.In this paper,a novel multi-branch cable harness layout design method is presented,which unites the probabilistic roadmap method(PRM)and the genetic algorithm.First,the engineering constraints of the cable harness layout are presented.An obstacle-based PRM used to construct non-interference and near to the surface roadmap is then described.In addition,a new genetic algorithm is proposed,and the algorithm structure of which is redesigned.In addition,the operation probability formula related to fitness is proposed to promote the efficiency of the branch structure design of the cable harness.A prototype system of a cable harness layout design was developed based on the method described in this study,and the method is applied to two scenarios to verify that a quality cable harness layout can be efficiently obtained using the proposed method.In summary,the cable harness layout design method described in this study can be used to quickly design a reasonable topological structure of a cable harness and to search for the corresponding routes of such a harness.展开更多
Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)...Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)as conjugation matrix due to its fascinating physico-chemical properties,maintaining enzymatic activity while circumventing cumbersome modification remains a formidable challenge.Herein,the freezing-directed conjugation of enzyme/nano interfaces was constructed without extra reagent.As the proof of concept,glucose oxidase(GOx)was chosen as model enzyme.The one-pot conjugation process can be facilely completed at−20°C under aqueous solution.Moreover,with the loading of GOx on AuNP at freezing,the enzyme exhibited superior catalytic activity and stability upon thermal and pH perturbation.The mechanism of boosted activity was then discussed in detail.It was found that higher loading density under freezing condition and more enzyme tending to bind AuNPs via Au-S bond were the main factors for the superior activity.More importantly,this methodology was universal and can also be applied to other enzyme which contains natural cysteine,such as horseradish peroxidase(HRP)and papain.This facile conjugation strategy accompanied by remarkable bioactivity expand the possibilities for enzymatic biosensing,microdevice and even drug delivery.展开更多
Nonalcoholic steatohepatitis(NASH)is a spectrum of chronic liver disease characterized by hepatic lipid metabolism disorder.Recent reports emphasized the contribution of triglyceride and diglyceride accumulation to NA...Nonalcoholic steatohepatitis(NASH)is a spectrum of chronic liver disease characterized by hepatic lipid metabolism disorder.Recent reports emphasized the contribution of triglyceride and diglyceride accumulation to NASH,while the other lipids associated with the NASH pathogenesis remained unexplored.The specific purpose of our study was to explore a novel pathogenesis and treatment strategy of NASH via profiling the metabolic characteristics of lipids.Herein,multi-omics techniques based on LC—Q-TOF/MS,LC—MS/MS and MS imaging were developed and used to screen the action targets related to NASH progress and treatment.A methionine and choline deficient(MCD)diet-induced mouse model of NASH was then constructed,and Schisandra lignans extract(SLE)was applied to alleviate hepatic damage by regulating the lipid metabolism-related enzymes CES2A and CYP4A14.Hepatic lipidomics indicated that MCD-diet led to aberrant accumulation of phosphatidylethanolamines(PEs),and SLE could significantly reduce the accumulation of intrahepatic PEs.Notably,exogenous PE(18:0/18:1)was proved to significantly aggravate the mitochondrial damage and hepatocyte apoptosis.Supplementing PE(18:0/18:1)also deteriorated the NASH progress by up regulating intrahepatic proinflammatory and fibrotic factors,while PE synthase inhibitor exerted a prominent hepatoprotective role.The current work provides new insights into the relationship between PE metabolism and the pathogenesis of NASH.展开更多
With the rapid development of inverter-based generators(IGs),power grid is faced with critical frequency stability challenges because the existing IGs have no inertia.To equip IGs with inertial response,researchers ha...With the rapid development of inverter-based generators(IGs),power grid is faced with critical frequency stability challenges because the existing IGs have no inertia.To equip IGs with inertial response,researchers have proposed several virtual inertia control methods,which can be classified into two categories:virtual synchronous generator(VSG)control and droop control based on rate of change of frequency(ROCOFdroop control).In this paper,the comparison between both virtual inertia control methods is conducted from three perspectives:mathematical model,output characteristic and small-signal stability.State-space models are firstly built to analyze the control mechanism of VSG control and ROCOF-droop control methods.Simulation and eigenvalue analysis are conducted to study the transient responses and oscillation characteristics of both methods,which is helpful to understand the advantages and limitations of existing virtual inertia control methods.Finally,the obtained theoretical results are validated through realtime laboratory(RT-LAB)hardware-in-loop simulation platform.展开更多
Background:Gestational weight gain(GWG)is associated with the risk of gestational diabetes mellitus(GDM).However,the effect of weight gain in different trimesters on the risk of GDM is unclear.This study aimed to eval...Background:Gestational weight gain(GWG)is associated with the risk of gestational diabetes mellitus(GDM).However,the effect of weight gain in different trimesters on the risk of GDM is unclear.This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen,China.In total,51,205 participants were included comprising two models(early pregnancy model and middle pregnancy model).Gestational weight(kg)was measured at each prenatal clinical visit using a standardized weight scale.Logistic regression analysis was used to assess the risk of GDM.Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model,the risk of GDM was 0.858 times lower(95%confidence interval[CI]:0.786,0.937)with insufficient GWG(iGWG)and 1.201 times higher(95%CI:1.097,1.316)with excessive GWG after adjustment.In the middle pregnancy model,the risk of GDM associated with iGWG increased 1.595 times(95%CI:1.418,1.794)after adjustment;for excessive GWG,no significant difference was found(P=0.223).Interaction analysis showed no interaction between GWG in early pregnancy(GWG-E)and GWG in middle pregnancy(GWG-M)(F=1.268;P=0.280).The mediation effect analysis indicated that GWG-M plays a partial mediating role,with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM.Strict control of weight gain in early pregnancy is needed,and sufficient nutrition should be provided in middle pregnancy.展开更多
Background:The fetal growth charts in widest use in China were published by Hadlock>35 years ago and were established on data from several hundred of American pregnant women.After that,>100 fetal growth charts w...Background:The fetal growth charts in widest use in China were published by Hadlock>35 years ago and were established on data from several hundred of American pregnant women.After that,>100 fetal growth charts were published around the world.We attempted to assess the impact of applying the long-standing Hadlock charts and other charts in a Chinese population and to compare their ability to predict newborn small for gestational age(SGA).Methods:For this retrospective observational study,we reviewed all pregnant women(n=106,455)who booked prenatal care with ultrasound measurements for fetal biometry at the Shenzhen Maternity and Child Healthcare Hospital between 2012 and 2019.A fractional polynomial regression model was applied to generate Shenzhen fetal growth chart ranges for head circumference(HC),biparietal diameter(BPD),abdominal circumference(AC),and femur length(FL).The differences between Shenzhen charts and published charts were quantified by calculating the Z-score.The impact of applying these published charts was quantifed by calculating the proportions of fetuses with biometric measurements below the 3rd centile of these charts.The sensitivity and area under the receiver operating characteristic curves of published charts to predict neonatal SGA(birthweight<10th centile)were assessed..Results:Following selection,169,980 scans of fetal biometry contributed by 41,032 pregnancies with reliable gestational age were analyzed.When using Hadlock references(<3rd centile),the proportions of small heads and short femurs were as high as 8.9%and 6.6%in late gestation,respectively.The INTERGROWTH-21st standards matched those of our observed curves better than other charts,in particular for fat-free biometry(HC and FL).When using AC<10th centile,all of these references were poor at predicting neonatal SGA.Conclusions:Applying long-standing Hadlock references could misclassify a large proportion of fetuses as SGA.INTERGROWTH-21st standard appears to be a safe option in China.For fat-based biometry,AC,a reference based on the Chinese population is needed.In addition,when applying published charts,particular care should be taken due to the discrepancy of measurement methods.展开更多
To predict grape maturity in solar greenhouses,a plant phenotype-monitoring platform(Phenofix,France)was used to obtain RGB images of grapes from expansion to maturity.Horizontal and longitudinal diameters,compactness...To predict grape maturity in solar greenhouses,a plant phenotype-monitoring platform(Phenofix,France)was used to obtain RGB images of grapes from expansion to maturity.Horizontal and longitudinal diameters,compactness,soluble solid content(SSC),titratable acid content,and the SSC/acid of grapes were measured and evaluated.The color values(R,G,B,H,S,andI)of the grape skin were determined and subjected to a back-propagation neural network algorithm(BPNN)to predict grape maturity.展开更多
Aiming at the dynamic multi-attribute decision making problem where the weight of each decision stage and attribute weight are completely unknown and the attribute value is unknown distributed three-parameter interval...Aiming at the dynamic multi-attribute decision making problem where the weight of each decision stage and attribute weight are completely unknown and the attribute value is unknown distributed three-parameter interval grey number,a threeparameter interval grey number dynamic multiattribute grey target decision making method with attribute value following quasi-normal distribution is proposed.Firstly,the position relationship between the“center of gravity”point and the kernel of the threeparameter interval grey number is discussed.According to the characteristicthat the attribute value obeys the quasi-normal distribution,anew weight isgiventothe“centerof gravity”point,and a new distance measure formula of the three-parameter interval grey number is defined.Secondly,according to the principle of maximum entropy,the objective programming model is constructed to determine the stage weight and attributeweight.Then,the schemes aresorted according to thesize of the comprehensive bull's-eye distance Finally an example is given to illustrate the effectiveness of the decision model.展开更多
Nowcasts of strong convective precipitation and radar-based quantitative precipitation estimations have always been hot yet challenging issues in meteorological sciences.Data-driven machine learning,especially deep le...Nowcasts of strong convective precipitation and radar-based quantitative precipitation estimations have always been hot yet challenging issues in meteorological sciences.Data-driven machine learning,especially deep learning,provides a new technical approach for the quantitative estimation and forecasting of precipitation.A high-quality,large-sample,and labeled training dataset is critical for the successful application of machine-learning technology to a specific field.The present study develops a benchmark dataset that can be applied to machine learning for minutescale quantitative precipitation estimation and forecasting(QpefBD),containing 231,978 samples of 3185 heavy precipitation events that occurred in 6 provinces of central and eastern China from April to October 2016-2018.Each individual sample consists of 8 products of weather radars at 6-min intervals within the time window of the corresponding event and products of 27 physical quantities at hourly intervals that describe the atmospheric dynamic and thermodynamic conditions.Two data labels,i.e.,ground precipitation intensity and areal coverage of heavy precipitation at 6-min intervals,are also included.The present study describes the basic components of the dataset and data processing and provides metrics for the evaluation of model performance on precipitation estimation and forecasting.Based on these evaluation metrics,some simple and commonly used methods are applied to evaluate precipitation estimates and forecasts.The results can serve as the benchmark reference for the performance evaluation of machine learning models using this dataset.This paper also gives some suggestions and scenarios of the QpefBD application.We believe that the application of this benchmark dataset will promote interdisciplinary collaboration between meteorological sciences and artificial intelligence sciences,providing a new way for the identification and forecast of heavy precipitation.展开更多
基金supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.21KJA330002)Natural Science Foundation of Jiangsu Province(Grant No.BK20211252)+3 种基金Young and Middle-aged Academic Leaders of the"Blue Project"in Jiangsu Universities(2022-2)Jiangsu Health and Family Planning Commission Medical Research Program(Grant No.Z2018035)Project of Public Health Research Center of Jiangnan University(Grant No.JUPH201842)Natural Science Foundation of Nanjing University of Chinese Medicine(Grant No.XZR2020021).
文摘As a potential endocrine-disrupting chemical,bisphenol F(BPF)may cause nonalcoholic fatty liver disease(NAFLD)-like changes,but the mechanisms under its pathogenesis as well as the intervention strategies remain unclear.Using the electron microscopy technology,along with LipidTOX Deep Red neutral and Bodipy 493/503 staining assays,we observed that BPF treatment elicited a striking accumulation of lipid droplets in HepG2 cells,accompanied by an increased total level of triglycerides.At the molecular level,the lipogenesis-associated mRNAs and proteins,including acetyl-CoA carboxylase,fatty acid synthase,stearoyl-CoA desaturase-1,peroxisome proliferator-activated receptor gamma,and CCAAT-enhancer-binding proteins,increased significantly via the AMP-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR)signaling regulation in both in vitro and in vivo studies.Furthermore,the immunofluorescence results also showed the robust lipogenesis induced by BPF,evident in its ability to promote the translocation of sterol regulatory element-binding protein-1c from the cytoplasm to the nuclei.To investigate the intervention strategies for BPF-induced NAFLD-like changes,we demonstrated that bellidifolin,isolated and purified from Swertia chirayita,significantly attenuated BPF-induced lipid droplet deposition in HepG2 cells and NAFLD-like changes in mice by blocking the expression of lipogenesis-associated proteins.Therefore,the present study elucidates the mechanisms underlying the BPF-induced lipid accumulation in HepG2 cells,while also highlighting the potential of bellidifolin to mitigate BPF-induced NAFLD-like changes.
基金supported by the State Grid Corporation of China Headquarter technology project (52010118000K)
文摘For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in comparison with that of an AC power grid. The Jacobian matrix used in the power-flow calculation was deduced through methods such as Newton–Laphson iteration and Taylor series expansion. Further, the operation effect of powerflow calculation on a true bipolar VSC-HVDC power grid was analyzed briefly. The elements of the Jacobian matrix corresponding to VSC were studied under the mode of droop control and the control strategy of VSC-HVDC power grid was analyzed in detail. The power-flow calculation model for VSC-HVDC power grid of the master–slave control mode was simplified using the PQ decomposition method of the power-flow calculation of an AC power grid. Moreover, a four-terminal model of the Zhangbei VSC-HVDC demonstration project was established and tested on MATLAB. The simulation results under two kinds of operating conditions were analyzed and compared to the results of BPA; the deviation between the power-flow results was studied. The results show that the proposed calculation method can provide a feasible support for calculating the power flow in VSC-HVDC grids.
基金Supported by National Natural Science Foundation of China(Grant No.51675050).
文摘Current studies on cable harness layouts have mainly focused on cable harness route planning.However,the topological structure of a cable harness is also extremely complex,and the branch structure of the cable harness can affect the route of the cable harness layout.The topological structure design of the cable harness is a key to such a layout.In this paper,a novel multi-branch cable harness layout design method is presented,which unites the probabilistic roadmap method(PRM)and the genetic algorithm.First,the engineering constraints of the cable harness layout are presented.An obstacle-based PRM used to construct non-interference and near to the surface roadmap is then described.In addition,a new genetic algorithm is proposed,and the algorithm structure of which is redesigned.In addition,the operation probability formula related to fitness is proposed to promote the efficiency of the branch structure design of the cable harness.A prototype system of a cable harness layout design was developed based on the method described in this study,and the method is applied to two scenarios to verify that a quality cable harness layout can be efficiently obtained using the proposed method.In summary,the cable harness layout design method described in this study can be used to quickly design a reasonable topological structure of a cable harness and to search for the corresponding routes of such a harness.
基金the National Natural Science Foundation of China(Nos.32001782 and 22222402)the Natural Science Foundation of Hunan Province(No.2021JJ40564)+2 种基金Changsha Municipal Natural Science Foundation(No.kq2007021)the Opening Foundation of State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University(No.2019013)Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.sklssm2023016).
文摘Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)as conjugation matrix due to its fascinating physico-chemical properties,maintaining enzymatic activity while circumventing cumbersome modification remains a formidable challenge.Herein,the freezing-directed conjugation of enzyme/nano interfaces was constructed without extra reagent.As the proof of concept,glucose oxidase(GOx)was chosen as model enzyme.The one-pot conjugation process can be facilely completed at−20°C under aqueous solution.Moreover,with the loading of GOx on AuNP at freezing,the enzyme exhibited superior catalytic activity and stability upon thermal and pH perturbation.The mechanism of boosted activity was then discussed in detail.It was found that higher loading density under freezing condition and more enzyme tending to bind AuNPs via Au-S bond were the main factors for the superior activity.More importantly,this methodology was universal and can also be applied to other enzyme which contains natural cysteine,such as horseradish peroxidase(HRP)and papain.This facile conjugation strategy accompanied by remarkable bioactivity expand the possibilities for enzymatic biosensing,microdevice and even drug delivery.
基金supported by the National Natural Science Foundation of China(Grant Number:82274194)Jiangsu Natural Science Funds(Grant Number:BK20211224,China)the Project of State Key Laboratory of Natural Medicines(Grant Number:SKLNMZZ202001,China)。
文摘Nonalcoholic steatohepatitis(NASH)is a spectrum of chronic liver disease characterized by hepatic lipid metabolism disorder.Recent reports emphasized the contribution of triglyceride and diglyceride accumulation to NASH,while the other lipids associated with the NASH pathogenesis remained unexplored.The specific purpose of our study was to explore a novel pathogenesis and treatment strategy of NASH via profiling the metabolic characteristics of lipids.Herein,multi-omics techniques based on LC—Q-TOF/MS,LC—MS/MS and MS imaging were developed and used to screen the action targets related to NASH progress and treatment.A methionine and choline deficient(MCD)diet-induced mouse model of NASH was then constructed,and Schisandra lignans extract(SLE)was applied to alleviate hepatic damage by regulating the lipid metabolism-related enzymes CES2A and CYP4A14.Hepatic lipidomics indicated that MCD-diet led to aberrant accumulation of phosphatidylethanolamines(PEs),and SLE could significantly reduce the accumulation of intrahepatic PEs.Notably,exogenous PE(18:0/18:1)was proved to significantly aggravate the mitochondrial damage and hepatocyte apoptosis.Supplementing PE(18:0/18:1)also deteriorated the NASH progress by up regulating intrahepatic proinflammatory and fibrotic factors,while PE synthase inhibitor exerted a prominent hepatoprotective role.The current work provides new insights into the relationship between PE metabolism and the pathogenesis of NASH.
基金supported by the technology project of State Grid Corporation of China and the technology project of State Grid Jibei Electric Power Corporation
文摘With the rapid development of inverter-based generators(IGs),power grid is faced with critical frequency stability challenges because the existing IGs have no inertia.To equip IGs with inertial response,researchers have proposed several virtual inertia control methods,which can be classified into two categories:virtual synchronous generator(VSG)control and droop control based on rate of change of frequency(ROCOFdroop control).In this paper,the comparison between both virtual inertia control methods is conducted from three perspectives:mathematical model,output characteristic and small-signal stability.State-space models are firstly built to analyze the control mechanism of VSG control and ROCOF-droop control methods.Simulation and eigenvalue analysis are conducted to study the transient responses and oscillation characteristics of both methods,which is helpful to understand the advantages and limitations of existing virtual inertia control methods.Finally,the obtained theoretical results are validated through realtime laboratory(RT-LAB)hardware-in-loop simulation platform.
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81830041 and 81771611)Shenzhen Science and Technology Innovation Committee Special Funding for Future Industry(No.JCYJ20170412140326739)。
文摘Background:Gestational weight gain(GWG)is associated with the risk of gestational diabetes mellitus(GDM).However,the effect of weight gain in different trimesters on the risk of GDM is unclear.This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen,China.In total,51,205 participants were included comprising two models(early pregnancy model and middle pregnancy model).Gestational weight(kg)was measured at each prenatal clinical visit using a standardized weight scale.Logistic regression analysis was used to assess the risk of GDM.Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model,the risk of GDM was 0.858 times lower(95%confidence interval[CI]:0.786,0.937)with insufficient GWG(iGWG)and 1.201 times higher(95%CI:1.097,1.316)with excessive GWG after adjustment.In the middle pregnancy model,the risk of GDM associated with iGWG increased 1.595 times(95%CI:1.418,1.794)after adjustment;for excessive GWG,no significant difference was found(P=0.223).Interaction analysis showed no interaction between GWG in early pregnancy(GWG-E)and GWG in middle pregnancy(GWG-M)(F=1.268;P=0.280).The mediation effect analysis indicated that GWG-M plays a partial mediating role,with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM.Strict control of weight gain in early pregnancy is needed,and sufficient nutrition should be provided in middle pregnancy.
基金supported by grants from the Shenzhen Science and Technology Project(No.JCYJ20210324130812035)The National Key Research and Development Program of China(No.2018YFC1002200).
文摘Background:The fetal growth charts in widest use in China were published by Hadlock>35 years ago and were established on data from several hundred of American pregnant women.After that,>100 fetal growth charts were published around the world.We attempted to assess the impact of applying the long-standing Hadlock charts and other charts in a Chinese population and to compare their ability to predict newborn small for gestational age(SGA).Methods:For this retrospective observational study,we reviewed all pregnant women(n=106,455)who booked prenatal care with ultrasound measurements for fetal biometry at the Shenzhen Maternity and Child Healthcare Hospital between 2012 and 2019.A fractional polynomial regression model was applied to generate Shenzhen fetal growth chart ranges for head circumference(HC),biparietal diameter(BPD),abdominal circumference(AC),and femur length(FL).The differences between Shenzhen charts and published charts were quantified by calculating the Z-score.The impact of applying these published charts was quantifed by calculating the proportions of fetuses with biometric measurements below the 3rd centile of these charts.The sensitivity and area under the receiver operating characteristic curves of published charts to predict neonatal SGA(birthweight<10th centile)were assessed..Results:Following selection,169,980 scans of fetal biometry contributed by 41,032 pregnancies with reliable gestational age were analyzed.When using Hadlock references(<3rd centile),the proportions of small heads and short femurs were as high as 8.9%and 6.6%in late gestation,respectively.The INTERGROWTH-21st standards matched those of our observed curves better than other charts,in particular for fat-free biometry(HC and FL).When using AC<10th centile,all of these references were poor at predicting neonatal SGA.Conclusions:Applying long-standing Hadlock references could misclassify a large proportion of fetuses as SGA.INTERGROWTH-21st standard appears to be a safe option in China.For fat-based biometry,AC,a reference based on the Chinese population is needed.In addition,when applying published charts,particular care should be taken due to the discrepancy of measurement methods.
基金This research was funded partially by the Natural Science Foundation of Liaoning Province(2021-MS-233)Key R&D Projects in Liaoning Province(Agriculture and Indus-trialization)(2021JH2/10200022)China Postdoctoral Science Foundation(2019M661128).
文摘To predict grape maturity in solar greenhouses,a plant phenotype-monitoring platform(Phenofix,France)was used to obtain RGB images of grapes from expansion to maturity.Horizontal and longitudinal diameters,compactness,soluble solid content(SSC),titratable acid content,and the SSC/acid of grapes were measured and evaluated.The color values(R,G,B,H,S,andI)of the grape skin were determined and subjected to a back-propagation neural network algorithm(BPNN)to predict grape maturity.
基金Supported by Humanities and Social Science Project of Henan Colleges and Universities(2022-ZZJH-067)。
文摘Aiming at the dynamic multi-attribute decision making problem where the weight of each decision stage and attribute weight are completely unknown and the attribute value is unknown distributed three-parameter interval grey number,a threeparameter interval grey number dynamic multiattribute grey target decision making method with attribute value following quasi-normal distribution is proposed.Firstly,the position relationship between the“center of gravity”point and the kernel of the threeparameter interval grey number is discussed.According to the characteristicthat the attribute value obeys the quasi-normal distribution,anew weight isgiventothe“centerof gravity”point,and a new distance measure formula of the three-parameter interval grey number is defined.Secondly,according to the principle of maximum entropy,the objective programming model is constructed to determine the stage weight and attributeweight.Then,the schemes aresorted according to thesize of the comprehensive bull's-eye distance Finally an example is given to illustrate the effectiveness of the decision model.
基金Supported by the National Key Research and Development Program of China(2018YFC1507305)。
文摘Nowcasts of strong convective precipitation and radar-based quantitative precipitation estimations have always been hot yet challenging issues in meteorological sciences.Data-driven machine learning,especially deep learning,provides a new technical approach for the quantitative estimation and forecasting of precipitation.A high-quality,large-sample,and labeled training dataset is critical for the successful application of machine-learning technology to a specific field.The present study develops a benchmark dataset that can be applied to machine learning for minutescale quantitative precipitation estimation and forecasting(QpefBD),containing 231,978 samples of 3185 heavy precipitation events that occurred in 6 provinces of central and eastern China from April to October 2016-2018.Each individual sample consists of 8 products of weather radars at 6-min intervals within the time window of the corresponding event and products of 27 physical quantities at hourly intervals that describe the atmospheric dynamic and thermodynamic conditions.Two data labels,i.e.,ground precipitation intensity and areal coverage of heavy precipitation at 6-min intervals,are also included.The present study describes the basic components of the dataset and data processing and provides metrics for the evaluation of model performance on precipitation estimation and forecasting.Based on these evaluation metrics,some simple and commonly used methods are applied to evaluate precipitation estimates and forecasts.The results can serve as the benchmark reference for the performance evaluation of machine learning models using this dataset.This paper also gives some suggestions and scenarios of the QpefBD application.We believe that the application of this benchmark dataset will promote interdisciplinary collaboration between meteorological sciences and artificial intelligence sciences,providing a new way for the identification and forecast of heavy precipitation.