BACKGROUND Esophageal varices(EV)are the most fatal complication of chronic hepatitis B(CHB)related cirrhosis.The prognosis is poor,especially after the first upper gastrointestinal hemorrhage.AIM To construct nomogra...BACKGROUND Esophageal varices(EV)are the most fatal complication of chronic hepatitis B(CHB)related cirrhosis.The prognosis is poor,especially after the first upper gastrointestinal hemorrhage.AIM To construct nomograms to predict the risk and severity of EV in patients with CHB related cirrhosis.METHODS Between 2016 and 2018,the patients with CHB related cirrhosis were recruited and divided into a training or validation cohort at The First Affiliated Hospital of Wenzhou Medical University.Clinical and ultrasonic parameters that were closely related to EV risk and severity were screened out by univariate and multivariate logistic regression analyses,and integrated into two nomograms,respectively.Both nomograms were internally and externally validated by calibration,concordance index(C-index),receiver operating characteristic curve,and decision curve analyses(DCA).RESULTS A total of 307 patients with CHB related cirrhosis were recruited.The independent risk factors for EV included Child-Pugh class[odds ratio(OR)=7.705,95%confidence interval(CI)=2.169-27.370,P=0.002],platelet count(OR=0.992,95%CI=0.984-1.000,P=0.044),splenic portal index(SPI)(OR=3.895,95%CI=1.630-9.308,P=0.002),and liver fibrosis index(LFI)(OR=3.603,95%CI=1.336-9.719,P=0.011);those of EV severity included Child-Pugh class(OR=5.436,95%CI=2.112-13.990,P<0.001),mean portal vein velocity(OR=1.479,95%CI=1.043-2.098,P=0.028),portal vein diameter(OR=1.397,95%CI=1.021-1.912,P=0.037),SPI(OR=1.463,95%CI=1.030-2.079,P=0.034),and LFI(OR=3.089,95%CI=1.442-6.617,P=0.004).Two nomograms(predicting EV risk and severity,respectively)were well-calibrated and had a favorable discriminative ability,with C-indexes of 0.916 and 0.846 in the training cohort,respectively,higher than those of other predictive indexes,like LFI(C-indexes=0.781 and 0.738),SPI(C-indexes=0.805 and 0.714),ratio of platelet count to spleen diameter(PSR)(C-indexes=0.822 and 0.726),King’s score(C-indexes=0.694 and 0.609),and Lok index(C-indexes=0.788 and 0.700).The areas under the curves(AUCs)of t展开更多
Our focus herein is on developing an effective taxonomy for the simultaneous and real-timemanagement of supply and demand chains.More specifically,the taxonomy is developed in terms ofits underpinning components and i...Our focus herein is on developing an effective taxonomy for the simultaneous and real-timemanagement of supply and demand chains.More specifically,the taxonomy is developed in terms ofits underpinning components and its research foci.From a components perspective,we first considerthe value chain of supplier,manufacturer,assembler,retailer,and customer,and then develop aconsistent set of definitions for supply and demand chains based on the location of the customer orderpenetration point.From a research perspective,we classify the methods that are employed in themanagement of these chains,based on whether supply and/or demand are flexible or fixed.Interestingly,our taxonomy highlights a very critical research area at which both supply and demandare flexible,thus manageable.Simultaneous management of supply and demand chains sets the stagefor mass customization which is concerned with meeting the needs of an individualized customermarket.Simultaneous and real-time management of supply and demand chains set the stage forreal-time mass customization(e.g.,wherein a tailor first laser scans an individual's upper torso andthen delivers a uniquely fitted jacket within a reasonable period,while the individual is waiting).Thebenefits of real-time mass customization can not be over-stated as products and services becomeindistinguishable and are co-produced in real-time,resulting in an overwhelming economicadvantage.展开更多
Severe disturbances in a power network can cause the system frequency to exceed the safe operating range.As the last defensive line for system emergency control,under frequency load shedding(UFLS)is an important metho...Severe disturbances in a power network can cause the system frequency to exceed the safe operating range.As the last defensive line for system emergency control,under frequency load shedding(UFLS)is an important method for preventing a wide range of frequency excursions.This paper proposes a hierarchical UFLS scheme of“centralized real-time decision-making and decentralized real-time control”for inter-connected systems.The centralized decision-layer of the scheme takes into account the importance of the load based on the equivalent transformation of kinetic energy(KE)and potential energy(PE)in the transient energy function(TEF),while the load PE is used to determine the load shedding amount(LSA)allocation in different loads after faults in real-time.At the same time,the influence of inertia loss is considered in the calculation of unbalanced power,and the decentralized control center is used to implement the one-stage UFLS process to compensate for the unbalanced power.Simulations are carried out on the modified New England 10-generator 39-bus system and 197-bus system in China to verify the performance of the proposed scheme.The results show that,compared with other LSA allocation indicators,the proposed alloca-tion indicators can achieve better fnadir and td.At the same time,compared with other multi-stage UFLS schemes,the proposed scheme can obtain the maximum fnadir with a smaller LSA in scenarios with high renewable energy sources(RES)penetration.展开更多
基金Supported by The Natural Science Foundation of Zhejiang Province,China,No.LY18H030011.
文摘BACKGROUND Esophageal varices(EV)are the most fatal complication of chronic hepatitis B(CHB)related cirrhosis.The prognosis is poor,especially after the first upper gastrointestinal hemorrhage.AIM To construct nomograms to predict the risk and severity of EV in patients with CHB related cirrhosis.METHODS Between 2016 and 2018,the patients with CHB related cirrhosis were recruited and divided into a training or validation cohort at The First Affiliated Hospital of Wenzhou Medical University.Clinical and ultrasonic parameters that were closely related to EV risk and severity were screened out by univariate and multivariate logistic regression analyses,and integrated into two nomograms,respectively.Both nomograms were internally and externally validated by calibration,concordance index(C-index),receiver operating characteristic curve,and decision curve analyses(DCA).RESULTS A total of 307 patients with CHB related cirrhosis were recruited.The independent risk factors for EV included Child-Pugh class[odds ratio(OR)=7.705,95%confidence interval(CI)=2.169-27.370,P=0.002],platelet count(OR=0.992,95%CI=0.984-1.000,P=0.044),splenic portal index(SPI)(OR=3.895,95%CI=1.630-9.308,P=0.002),and liver fibrosis index(LFI)(OR=3.603,95%CI=1.336-9.719,P=0.011);those of EV severity included Child-Pugh class(OR=5.436,95%CI=2.112-13.990,P<0.001),mean portal vein velocity(OR=1.479,95%CI=1.043-2.098,P=0.028),portal vein diameter(OR=1.397,95%CI=1.021-1.912,P=0.037),SPI(OR=1.463,95%CI=1.030-2.079,P=0.034),and LFI(OR=3.089,95%CI=1.442-6.617,P=0.004).Two nomograms(predicting EV risk and severity,respectively)were well-calibrated and had a favorable discriminative ability,with C-indexes of 0.916 and 0.846 in the training cohort,respectively,higher than those of other predictive indexes,like LFI(C-indexes=0.781 and 0.738),SPI(C-indexes=0.805 and 0.714),ratio of platelet count to spleen diameter(PSR)(C-indexes=0.822 and 0.726),King’s score(C-indexes=0.694 and 0.609),and Lok index(C-indexes=0.788 and 0.700).The areas under the curves(AUCs)of t
文摘Our focus herein is on developing an effective taxonomy for the simultaneous and real-timemanagement of supply and demand chains.More specifically,the taxonomy is developed in terms ofits underpinning components and its research foci.From a components perspective,we first considerthe value chain of supplier,manufacturer,assembler,retailer,and customer,and then develop aconsistent set of definitions for supply and demand chains based on the location of the customer orderpenetration point.From a research perspective,we classify the methods that are employed in themanagement of these chains,based on whether supply and/or demand are flexible or fixed.Interestingly,our taxonomy highlights a very critical research area at which both supply and demandare flexible,thus manageable.Simultaneous management of supply and demand chains sets the stagefor mass customization which is concerned with meeting the needs of an individualized customermarket.Simultaneous and real-time management of supply and demand chains set the stage forreal-time mass customization(e.g.,wherein a tailor first laser scans an individual's upper torso andthen delivers a uniquely fitted jacket within a reasonable period,while the individual is waiting).Thebenefits of real-time mass customization can not be over-stated as products and services becomeindistinguishable and are co-produced in real-time,resulting in an overwhelming economicadvantage.
基金supported in part by the National Key R&D Program of China“Response-driven intelligent enhanced analysis and control for bulk power system stability”under Grant 2021YFB2400800.
文摘Severe disturbances in a power network can cause the system frequency to exceed the safe operating range.As the last defensive line for system emergency control,under frequency load shedding(UFLS)is an important method for preventing a wide range of frequency excursions.This paper proposes a hierarchical UFLS scheme of“centralized real-time decision-making and decentralized real-time control”for inter-connected systems.The centralized decision-layer of the scheme takes into account the importance of the load based on the equivalent transformation of kinetic energy(KE)and potential energy(PE)in the transient energy function(TEF),while the load PE is used to determine the load shedding amount(LSA)allocation in different loads after faults in real-time.At the same time,the influence of inertia loss is considered in the calculation of unbalanced power,and the decentralized control center is used to implement the one-stage UFLS process to compensate for the unbalanced power.Simulations are carried out on the modified New England 10-generator 39-bus system and 197-bus system in China to verify the performance of the proposed scheme.The results show that,compared with other LSA allocation indicators,the proposed alloca-tion indicators can achieve better fnadir and td.At the same time,compared with other multi-stage UFLS schemes,the proposed scheme can obtain the maximum fnadir with a smaller LSA in scenarios with high renewable energy sources(RES)penetration.
