For the goals of security and privacy preservation,we propose a blind batch encryption-and public ledger-based data sharing protocol that allows the integrity of sensitive data to be audited by a public ledger and all...For the goals of security and privacy preservation,we propose a blind batch encryption-and public ledger-based data sharing protocol that allows the integrity of sensitive data to be audited by a public ledger and allows privacy information to be preserved.Data owners can tightly manage their data with efficient revocation and only grant one-time adaptive access for the fulfillment of the requester.We prove that our protocol is semanticallly secure,blind,and secure against oblivious requesters and malicious file keepers.We also provide security analysis in the context of four typical attacks.展开更多
In eukaryotic organisms,the most common internal modification of messenger RNA(m RNA)is N6-methyladenosine(m6A).This modification can be dynamically and reversibly controlled by specific enzymes known as m6A writers a...In eukaryotic organisms,the most common internal modification of messenger RNA(m RNA)is N6-methyladenosine(m6A).This modification can be dynamically and reversibly controlled by specific enzymes known as m6A writers and erasers.The fat-mass and obesity-associated protein(FTO)catalyzes RNA demethylation and plays a critical role in various physiological and pathological processes.Our research identified dynamic alterations in both m6A and FTO during the assembly of primordial follicles,with an inverse relationship observed for m6A levels and nuclear-localized FTO expression.Application of Fto small interfering RNA(si RNA)altered the expression of genes related to cell proliferation,hormone regulation,and cell chemotaxis,and affected RNA alternative splicing.Overexpression of the full-length Fto gene led to changes in m6A levels,alternative splicing of Cdk5,cell proliferation,cell cycle progression,and proportion of primordial follicles.Conversely,overexpression of Fto lacking a nuclear localization signal(NLS)did not significantly alter m6A levels or primordial follicle assembly.These findings suggest that FTO,localized in the nucleus but not in the cytoplasm,regulates RNA m6A demethylation and plays a role in cell proliferation,cell cycle progression,and primordial follicle assembly.These results highlight the potential of m6A and its eraser FTO as possible biomarkers and therapeutic targets.展开更多
BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,i...BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.展开更多
The prognostics health management(PHM)fromthe systematic viewis critical to the healthy continuous operation of processmanufacturing systems(PMS),with different kinds of dynamic interference events.This paper proposes...The prognostics health management(PHM)fromthe systematic viewis critical to the healthy continuous operation of processmanufacturing systems(PMS),with different kinds of dynamic interference events.This paper proposes a three leveled digital twinmodel for the systematic PHMof PMSs.The unit-leveled digital twinmodel of each basic device unit of PMSs is constructed based on edge computing,which can provide real-time monitoring and analysis of the device status.The station-leveled digital twin models in the PMSs are designed to optimize and control the process parameters,which are deployed for the manufacturing execution on the fog server.The shop-leveled digital twin maintenancemodel is designed for production planning,which gives production instructions fromthe private industrial cloud server.To cope with the dynamic disturbances of a PMS,a big data-driven framework is proposed to control the three-level digital twin models,which contains indicator prediction,influence evaluation,and decisionmaking.Finally,a case study with a real chemical fiber system is introduced to illustrate the effectiveness of the digital twin model with edge-fog-cloud computing for the systematic PHM of PMSs.The result demonstrates that the three-leveled digital twin model for the systematic PHM in PMSs works well in the system’s respects.展开更多
Objective:Lung metastasis is a common and fatal complication of liver transplantation for hepatocellular carcinoma(HCC).The precise prediction of post-transplant lung metastasis in the early phase is of great value.Me...Objective:Lung metastasis is a common and fatal complication of liver transplantation for hepatocellular carcinoma(HCC).The precise prediction of post-transplant lung metastasis in the early phase is of great value.Methods:The mRNA profiles of primary and paired lung metastatic lesions were analyzed to determine key signaling pathways.We enrolled 241 HCC patients who underwent liver transplantation from three centers.Tissue microarrays were used to evaluate the prognostic capacity of tumor necrosis factor(TNF),tumor necrosis factor receptor 1(TNFR1),and TNFR2,particularly for post-transplant lung metastasis.Results:Comparison of primary and lung metastatic lesions revealed that the TNF-dependent signaling pathway was related to lung metastasis of HCC.The expression of TNF was degraded in comparison to that in para-tumor tissues(P<0.001).The expression of key receptors in the TNF-dependent signaling pathway,TNFR1 and TNFR2,was higher in HCC tissues than in para-tumor tissues(P<0.001).TNF and TNFR1 showed no relationship with patients’outcomes,whereas elevated TNFR2 in tumor tissue was significantly associated with worse overall survival(OS)and increased recurrence risk(5-year OS rate:31.9%vs.62.5%,P<0.001).Notably,elevated TNFR2 levels were also associated with an increased risk of post-transplant lung metastasis(hazard ratio:1.146;P<0.001).Cox regression analysis revealed that TNFR2,Hangzhou criteria,age,and hepatitis B surface antigen were independent risk factors for post-transplant lung metastasis,and a novel nomogram was established accordingly.The nomogram achieved excellent prognostic efficiency(area under time-dependent receiver operating characteristic=0.755,concordance-index=0.779)and was superior to conventional models,such as the Milan criteria.Conclusions:TNFR2 is a potent prognostic biomarker for predicting post-transplant lung metastasis in patients with HCC.A nomogram incorporating TNFR2 deserves to be a helpful prognostic tool in liver transplantation for HCC.展开更多
High-order harmonics q(ψ_(s))=1 energetic particle modes(EPMs)have been observed in toroidal plasmas experiments with neutral beam injection.To investigate these phenomena,linear properties and nonlinear dynamics of ...High-order harmonics q(ψ_(s))=1 energetic particle modes(EPMs)have been observed in toroidal plasmas experiments with neutral beam injection.To investigate these phenomena,linear properties and nonlinear dynamics of these EPMs driven by passing energetic particles(EPs)are studied via the global hybrid kinetic-magnetohydrodynamic code M3D-K.Simulation results demonstrate that passing EPs'effects on high mode-number harmonics(q(ψ_(s))=m/n=2/2,3/3,4/4)instability are more obvious than the q(ψ_(s))=1/1 mode,especially when q-profile is sufficiently flat in the core region.Furthermore,the effects of the pitch angleΛ_0 and beam ion pressure P_(hot)/P_(total)on the features of high n components are also analyzed specifically.It is found that there exists only one resonant condition for these EPMs.In the nonlinear phase,these high mode-number harmonics can induce significant energetic ions redistribution and chirping up phenomena,which differs from the classical fishbone excited by passing EPs.These discoveries are conducive to better apprehend the underlying physical mechanisms of the highorder harmonics driven by passing EPs.展开更多
Metal-ion capacitors could merit advantages from both batteries and capacitors,but they need to overcome the severe restrictions from their sluggish reaction kinetics of the battery type electrode and low specific cap...Metal-ion capacitors could merit advantages from both batteries and capacitors,but they need to overcome the severe restrictions from their sluggish reaction kinetics of the battery type electrode and low specific capacitance of capacitor type electrode for both high energy and power density.Herein,we use the Kirkendall effect for the first time to synthesize unique tubular hierarchical molybdenum dioxide with encapsulated nitrogen-doped carbon sheets while in situ realizing phosphorus-doping to create rich oxygen vacancies(P-MoO_(2-x)@NP-C)as a sodium-ion electrode.Experimental and theoretical analysis confirm that the P-doping introduced oxygen defects can partially convert the high-bond-energy Mo–O to low-bond-energy Mo–P,resulting in a low oxidation state of molybdenum for enhanced surface reactivity and rapid reaction kinetics.The as-prepared P-MoO_(2-x)@NP-C as an ion-battery electrode is further used to pair active N-doped carbon nanosheet(N-C-A)electrode for Na-ion hybrid capacitor,delivering excellent performance with an energy density of 140.3 Wh kg^(−1),a power density of 188.5 W kg^(−1)and long stable life in non-aqueous solution,which ranks the best among all reported MoO x-based hybrid capacitors.P-MoO_(2-x)@NP-C is also used to fabricate a zinc-ion hybrid capacitor,also accomplishing a remarkable energy density of 43.8 Wh kg^(−1),a power density of 93.9 W kg^(−1),and a long stable life@2A g^(−1)of 32000 cycles in aqueous solutions,solidly verifying its universal significance.This work not only demonstrates an innovative approach to synthesize high-performance metal ion hybrid capacitor materials but also reveals certain scientific insights into electron transfer enhancement mechanisms.展开更多
BACKGROUND Postpartum ovarian vein thrombosis(POVT)is a rare puerperal complication.It is easily missed or misdiagnosed due to its insidious onset and lack of specific clinical symptoms and signs.This paper reports tw...BACKGROUND Postpartum ovarian vein thrombosis(POVT)is a rare puerperal complication.It is easily missed or misdiagnosed due to its insidious onset and lack of specific clinical symptoms and signs.This paper reports two patients who developed right ovarian vein thrombosis after cesarean section and vaginal delivery,respectively.CASE SUMMARY Case 1 was a 32-year-old female who underwent a cesarean section in labor at 40 wk of gestation due to fetal distress.The patient was persistently febrile after the operation and escalated antibiotic treatment was ineffective.POVT was diagnosed by abdominal computed tomography(CT)and was treated by increasing the dose of low molecular weight heparin(LMWH).Case 2 was a 21-year-old female with a spontaneous vaginal delivery at 39 wk of gestation.The patient developed fever and abdominal pain 3 days after delivery.POVT was promptly identified by abdominal CT,and the condition was quickly controlled after treatment with LMWH and antibiotics.CONCLUSION These two cases occurred after cesarean section and vaginal delivery,respectively.The diagnosis was mainly based on imaging examination due to the unspecific clinical symptoms and signs,the CT scan provided an especially high diagnostic value.Comparing these two cases,escalating antibiotics alone did not provide significant therapeutic benefit,but the early escalation of anticoagulant dosage seemed to shorten the disease course.Therefore,early diagnosis by CT followed by aggressive anticoagulation might have a positive effect on improving the prognosis of the disease.展开更多
Pollution flashover is one of themajor insulation accidents that can occur inmodern power systems.If the local arc is not sufficiently elongated by the creepage distance,the flashover performance of the insulator will...Pollution flashover is one of themajor insulation accidents that can occur inmodern power systems.If the local arc is not sufficiently elongated by the creepage distance,the flashover performance of the insulator will decrease.The insulator structure and equivalent salt deposition density(ESDD)are the main factors affecting the arc path and length.To investigate the forms of arc paths under different insulator structures and their influence on flashover characteristics,a platformfor recording arc paths is established.This study presents amethod to identify the pattern and distribution of insulator arc paths based on the effect of initial arc on electric field distribution.The results show that there are two main types of local arc paths between umbrellas—the cling-surface arc and the air-jump arc.Moreover,the air-jump arc includes two types—the bridging arc and the gap arc.With the increase in umbrella spacing and ESDD,the probability of arc propagation along the surface increases.The use of the creepage distance can be improved by changing the creepage coefficient to increase the distance between umbrellas.This method has over 90%accuracy.This study is of great significance for improving insulator structure and reducing pollution flashover accidents.展开更多
基金partially supported by the National Natural Science Foundation of China under grant no.62372245the Foundation of Yunnan Key Laboratory of Blockchain Application Technology under Grant 202105AG070005+1 种基金in part by the Foundation of State Key Laboratory of Public Big Datain part by the Foundation of Key Laboratory of Computational Science and Application of Hainan Province under Grant JSKX202202。
文摘For the goals of security and privacy preservation,we propose a blind batch encryption-and public ledger-based data sharing protocol that allows the integrity of sensitive data to be audited by a public ledger and allows privacy information to be preserved.Data owners can tightly manage their data with efficient revocation and only grant one-time adaptive access for the fulfillment of the requester.We prove that our protocol is semanticallly secure,blind,and secure against oblivious requesters and malicious file keepers.We also provide security analysis in the context of four typical attacks.
基金supported by the Natural Science Foundation of Shandong Province,China (ZR2017MC033)National Key Research and Development Program of China (2023YFD1300504)Taishan Scholar Construction Foundation of Shandong Province,China (ts20190946)。
文摘In eukaryotic organisms,the most common internal modification of messenger RNA(m RNA)is N6-methyladenosine(m6A).This modification can be dynamically and reversibly controlled by specific enzymes known as m6A writers and erasers.The fat-mass and obesity-associated protein(FTO)catalyzes RNA demethylation and plays a critical role in various physiological and pathological processes.Our research identified dynamic alterations in both m6A and FTO during the assembly of primordial follicles,with an inverse relationship observed for m6A levels and nuclear-localized FTO expression.Application of Fto small interfering RNA(si RNA)altered the expression of genes related to cell proliferation,hormone regulation,and cell chemotaxis,and affected RNA alternative splicing.Overexpression of the full-length Fto gene led to changes in m6A levels,alternative splicing of Cdk5,cell proliferation,cell cycle progression,and proportion of primordial follicles.Conversely,overexpression of Fto lacking a nuclear localization signal(NLS)did not significantly alter m6A levels or primordial follicle assembly.These findings suggest that FTO,localized in the nucleus but not in the cytoplasm,regulates RNA m6A demethylation and plays a role in cell proliferation,cell cycle progression,and primordial follicle assembly.These results highlight the potential of m6A and its eraser FTO as possible biomarkers and therapeutic targets.
文摘BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.
基金supported by the Fundamental Research Funds for The Central Universities(Grant No.2232021A-08)National Natural Science Foundation of China(GrantNo.51905091)Shanghai Sailing Program(Grand No.19YF1401500).
文摘The prognostics health management(PHM)fromthe systematic viewis critical to the healthy continuous operation of processmanufacturing systems(PMS),with different kinds of dynamic interference events.This paper proposes a three leveled digital twinmodel for the systematic PHMof PMSs.The unit-leveled digital twinmodel of each basic device unit of PMSs is constructed based on edge computing,which can provide real-time monitoring and analysis of the device status.The station-leveled digital twin models in the PMSs are designed to optimize and control the process parameters,which are deployed for the manufacturing execution on the fog server.The shop-leveled digital twin maintenancemodel is designed for production planning,which gives production instructions fromthe private industrial cloud server.To cope with the dynamic disturbances of a PMS,a big data-driven framework is proposed to control the three-level digital twin models,which contains indicator prediction,influence evaluation,and decisionmaking.Finally,a case study with a real chemical fiber system is introduced to illustrate the effectiveness of the digital twin model with edge-fog-cloud computing for the systematic PHM of PMSs.The result demonstrates that the three-leveled digital twin model for the systematic PHM in PMSs works well in the system’s respects.
基金the National Key Research and Development Program of China(No.2021YFA1100500)the Major Research Plan of the National Natural Science Foundation of China(No.92159202)+2 种基金the Key Research&Development Plan of Zhejiang Province(No.2019C03050),the Key Research&Development Plan of Zhejiang Province(No.2021C03118)National S&T Major Project(No.2017ZX10203205)the Health Science&Technology Plan of Zhejiang Province(No.2022RC060)。
文摘Objective:Lung metastasis is a common and fatal complication of liver transplantation for hepatocellular carcinoma(HCC).The precise prediction of post-transplant lung metastasis in the early phase is of great value.Methods:The mRNA profiles of primary and paired lung metastatic lesions were analyzed to determine key signaling pathways.We enrolled 241 HCC patients who underwent liver transplantation from three centers.Tissue microarrays were used to evaluate the prognostic capacity of tumor necrosis factor(TNF),tumor necrosis factor receptor 1(TNFR1),and TNFR2,particularly for post-transplant lung metastasis.Results:Comparison of primary and lung metastatic lesions revealed that the TNF-dependent signaling pathway was related to lung metastasis of HCC.The expression of TNF was degraded in comparison to that in para-tumor tissues(P<0.001).The expression of key receptors in the TNF-dependent signaling pathway,TNFR1 and TNFR2,was higher in HCC tissues than in para-tumor tissues(P<0.001).TNF and TNFR1 showed no relationship with patients’outcomes,whereas elevated TNFR2 in tumor tissue was significantly associated with worse overall survival(OS)and increased recurrence risk(5-year OS rate:31.9%vs.62.5%,P<0.001).Notably,elevated TNFR2 levels were also associated with an increased risk of post-transplant lung metastasis(hazard ratio:1.146;P<0.001).Cox regression analysis revealed that TNFR2,Hangzhou criteria,age,and hepatitis B surface antigen were independent risk factors for post-transplant lung metastasis,and a novel nomogram was established accordingly.The nomogram achieved excellent prognostic efficiency(area under time-dependent receiver operating characteristic=0.755,concordance-index=0.779)and was superior to conventional models,such as the Milan criteria.Conclusions:TNFR2 is a potent prognostic biomarker for predicting post-transplant lung metastasis in patients with HCC.A nomogram incorporating TNFR2 deserves to be a helpful prognostic tool in liver transplantation for HCC.
基金supported by National Key R&D Program of China(Nos.2019YFE03050002,2018YFE0310400,and 2022YFE03040002)National Natural Science Foundation of China(Nos.12005003 and 11975270)Science Foundation of Institute of Plasma Physics,Chinese Academy of Sciences(No.DSJJ-2022-04)。
文摘High-order harmonics q(ψ_(s))=1 energetic particle modes(EPMs)have been observed in toroidal plasmas experiments with neutral beam injection.To investigate these phenomena,linear properties and nonlinear dynamics of these EPMs driven by passing energetic particles(EPs)are studied via the global hybrid kinetic-magnetohydrodynamic code M3D-K.Simulation results demonstrate that passing EPs'effects on high mode-number harmonics(q(ψ_(s))=m/n=2/2,3/3,4/4)instability are more obvious than the q(ψ_(s))=1/1 mode,especially when q-profile is sufficiently flat in the core region.Furthermore,the effects of the pitch angleΛ_0 and beam ion pressure P_(hot)/P_(total)on the features of high n components are also analyzed specifically.It is found that there exists only one resonant condition for these EPMs.In the nonlinear phase,these high mode-number harmonics can induce significant energetic ions redistribution and chirping up phenomena,which differs from the classical fishbone excited by passing EPs.These discoveries are conducive to better apprehend the underlying physical mechanisms of the highorder harmonics driven by passing EPs.
基金the financial support from the National Natural Science Foundation of China(51802269).
文摘Metal-ion capacitors could merit advantages from both batteries and capacitors,but they need to overcome the severe restrictions from their sluggish reaction kinetics of the battery type electrode and low specific capacitance of capacitor type electrode for both high energy and power density.Herein,we use the Kirkendall effect for the first time to synthesize unique tubular hierarchical molybdenum dioxide with encapsulated nitrogen-doped carbon sheets while in situ realizing phosphorus-doping to create rich oxygen vacancies(P-MoO_(2-x)@NP-C)as a sodium-ion electrode.Experimental and theoretical analysis confirm that the P-doping introduced oxygen defects can partially convert the high-bond-energy Mo–O to low-bond-energy Mo–P,resulting in a low oxidation state of molybdenum for enhanced surface reactivity and rapid reaction kinetics.The as-prepared P-MoO_(2-x)@NP-C as an ion-battery electrode is further used to pair active N-doped carbon nanosheet(N-C-A)electrode for Na-ion hybrid capacitor,delivering excellent performance with an energy density of 140.3 Wh kg^(−1),a power density of 188.5 W kg^(−1)and long stable life in non-aqueous solution,which ranks the best among all reported MoO x-based hybrid capacitors.P-MoO_(2-x)@NP-C is also used to fabricate a zinc-ion hybrid capacitor,also accomplishing a remarkable energy density of 43.8 Wh kg^(−1),a power density of 93.9 W kg^(−1),and a long stable life@2A g^(−1)of 32000 cycles in aqueous solutions,solidly verifying its universal significance.This work not only demonstrates an innovative approach to synthesize high-performance metal ion hybrid capacitor materials but also reveals certain scientific insights into electron transfer enhancement mechanisms.
文摘BACKGROUND Postpartum ovarian vein thrombosis(POVT)is a rare puerperal complication.It is easily missed or misdiagnosed due to its insidious onset and lack of specific clinical symptoms and signs.This paper reports two patients who developed right ovarian vein thrombosis after cesarean section and vaginal delivery,respectively.CASE SUMMARY Case 1 was a 32-year-old female who underwent a cesarean section in labor at 40 wk of gestation due to fetal distress.The patient was persistently febrile after the operation and escalated antibiotic treatment was ineffective.POVT was diagnosed by abdominal computed tomography(CT)and was treated by increasing the dose of low molecular weight heparin(LMWH).Case 2 was a 21-year-old female with a spontaneous vaginal delivery at 39 wk of gestation.The patient developed fever and abdominal pain 3 days after delivery.POVT was promptly identified by abdominal CT,and the condition was quickly controlled after treatment with LMWH and antibiotics.CONCLUSION These two cases occurred after cesarean section and vaginal delivery,respectively.The diagnosis was mainly based on imaging examination due to the unspecific clinical symptoms and signs,the CT scan provided an especially high diagnostic value.Comparing these two cases,escalating antibiotics alone did not provide significant therapeutic benefit,but the early escalation of anticoagulant dosage seemed to shorten the disease course.Therefore,early diagnosis by CT followed by aggressive anticoagulation might have a positive effect on improving the prognosis of the disease.
基金This work was supported by the National Natural Science Foundation of China(52007138)Chengdu Technology Innovation R&D Project(2022-YF05-00971-SN).
文摘Pollution flashover is one of themajor insulation accidents that can occur inmodern power systems.If the local arc is not sufficiently elongated by the creepage distance,the flashover performance of the insulator will decrease.The insulator structure and equivalent salt deposition density(ESDD)are the main factors affecting the arc path and length.To investigate the forms of arc paths under different insulator structures and their influence on flashover characteristics,a platformfor recording arc paths is established.This study presents amethod to identify the pattern and distribution of insulator arc paths based on the effect of initial arc on electric field distribution.The results show that there are two main types of local arc paths between umbrellas—the cling-surface arc and the air-jump arc.Moreover,the air-jump arc includes two types—the bridging arc and the gap arc.With the increase in umbrella spacing and ESDD,the probability of arc propagation along the surface increases.The use of the creepage distance can be improved by changing the creepage coefficient to increase the distance between umbrellas.This method has over 90%accuracy.This study is of great significance for improving insulator structure and reducing pollution flashover accidents.
