Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating du...Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.展开更多
The outbreak of coronavirus disease 2019 has seriously threatened human health.Rapidly and sensitively detecting SARSCoV-2 viruses can help control the spread of viruses.However,it is an arduous challenge to apply sem...The outbreak of coronavirus disease 2019 has seriously threatened human health.Rapidly and sensitively detecting SARSCoV-2 viruses can help control the spread of viruses.However,it is an arduous challenge to apply semiconductor-based substrates for virus SERS detection due to their poor sensitivity.Therefore,it is worthwhile to search novel semiconductor-based substrates with excellent SERS sensitivity.Herein we report,for the first time,Nb2C and Ta2C MXenes exhibit a remarkable SERS enhancement,which is synergistically enabled by the charge transfer resonance enhancement and electromagnetic enhancement.Their SERS sensitivity is optimized to 3.0×10^6 and 1.4×10^6 under the optimal resonance excitation wavelength of 532 nm.Additionally,remarkable SERS sensitivity endows Ta2C MXenes with capability to sensitively detect and accurately identify the SARS-CoV-2 spike protein.Moreover,its detection limit is as low as 5×10^−9 M,which is beneficial to achieve real-time monitoring and early warning of novel coronavirus.This research not only provides helpful theoretical guidance for exploring other novel SERS-active semiconductor-based materials but also provides a potential candidate for the practical applications of SERS technology.展开更多
Sensitivity analysis in chaotic dynamical systems is a challenging task from a computational point of view.In this work,we present a numerical investigation of a novel approach,known as the space-split sensitivity or ...Sensitivity analysis in chaotic dynamical systems is a challenging task from a computational point of view.In this work,we present a numerical investigation of a novel approach,known as the space-split sensitivity or S3 algorithm.The S3 algorithm is an ergodic-averaging method to differentiate statistics in ergodic,chaotic systems,rigorously based on the theory of hyperbolic dynamics.We illustrate S3 on one-dimensional chaotic maps,revealing its computational advantage over na?ve finite difference computations of the same statistical response.In addition,we provide an intuitive explanation of the key components of the S3 algorithm,including the density gradient function.展开更多
A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phas...A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phased mission systems( PMS). The simulation strategy of GMS based on a Petri net and Monte Carlo method was presented which had broad applicability. Finally,the GMS and Birnbaum's sensitivity of components in a PMS example were compared. The GMS of component is demonstrated to be more adaptable to reflect the component mission sensitivity when the rated reliability parameters of components cannot be obtained, and components have state dependency or the system is subjected to common cause failure.展开更多
BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant biliary tract cancer with poor prognosis.Previous studies have implicated the gut microbiota in CCA,but evidence for causal mechanisms is lacking.AIM To investig...BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant biliary tract cancer with poor prognosis.Previous studies have implicated the gut microbiota in CCA,but evidence for causal mechanisms is lacking.AIM To investigate the causal relationship between gut microbiota and CCA risk.METHODS We performed a two-sample mendelian randomization study to evaluate potential causal associations between gut microbiota and CCA risk using genome-wide association study summary statistics for 196 gut microbial taxa and CCA.Genetic variants were used as instrumental variables.Multiple sensitivity analyses assessed result robustness.RESULTS Fifteen gut microbial taxa showed significant causal associations with CCA risk.Higher genetically predicted abundance of genus Eubacteriumnodatum group,genus Ruminococcustorques group,genus Coprococcus,genus Dorea,and phylum Actinobacteria were associated with reduced risk of gallbladder cancer and extrahepatic CCA.Increased intrahepatic CCA risk was associated with higher abundance of family Veillonellaceae,genus Alistipes,order Enterobacteriales,and phylum Firmicutes.Protective effects against CCA were suggested for genus Collinsella,genus Eisenbergiella,genus Anaerostipes,genus Paraprevotella,genus Parasutterella,and phylum Verrucomicrobia.Sensitivity analyses indicated these findings were reliable without pleiotropy.CONCLUSION This pioneering study provides novel evidence that specific gut microbiota may play causal roles in CCA risk.Further experimental validation of these candidate microbes is warranted to consolidate causality and mechanisms.展开更多
AIM: To investigate sensations to multimodal pain stimulation in the metaplastic and normal parts of the esophagus in patients with Barrett’s esophagus (BE). METHODS: Fifteen patients with BE and 15 age-matched healt...AIM: To investigate sensations to multimodal pain stimulation in the metaplastic and normal parts of the esophagus in patients with Barrett’s esophagus (BE). METHODS: Fifteen patients with BE and 15 age-matched healthy volunteers were subjected to mechanical, thermal and electrical pain stimuli of the esophagus. Both the metaplastic part and the normal part (4 and 14 cm, respectively, above the esophago-gastric junction) were examined. At sensory thresholds the stimulation intensity, referred pain areas, and evoked brain potentials were recorded. RESULTS: Patients were hyposensitive to heat stimulation both in the metaplastic part [median stimulation time to reach the pain detection threshold: 15 (12-34) s vs 14 (6-23) s in controls; F = 4.5, P = 0.04] and the normal part of the esophagus [median 17 (6-32) s vs 13 (8-20) s in controls; F = 6.2, P = 0.02]. Furthermore, patients were hyposensitive in the metaplastic part of the esophagus to mechanical distension [median volume at moderate pain: 50 (20-50) mL vs 33 (13-50) mL in controls; F = 5.7, P = 0.02]. No indication of central nervous system abnormalities was present, as responses were comparable between groups to electrical pain stimuli in the metaplastic part [median current evoking moderate pain: 13 (6-26) mA vs 12 (9-24) mA in controls; F = 0.1, P = 0.7], and in the normal part of the esophagus [median current evoking moderate pain: 9 (6-16) mA, vs 11 (5-11) mA in controls; F = 3.4, P = 0.07]. Furthermore, no differences were seen for the referred pain areas (P-values all > 0.3) or latencies and amplitudes for the evoked brain potentials (P-values all > 0.1). CONCLUSION: Patients with BE are hyposensitive both in the metaplastic and normal part of esophagus likely as a result of abnormalities affecting peripheral nerve pathways.展开更多
Compared with the conventionally used i=iosinωt alternating current, using asymmetric triangular and pulse wave as input signals can greatly enhance the incision's sensitivity of 'dE/dt-E'oscillogram.
Geometry sensitivity of magnetohydrodynamics （MHD） duct flow and some ab- normal phenomena deviating from the classical MHD laws were measured in an experimental investigation of the MHD effect of the flow channel i...Geometry sensitivity of magnetohydrodynamics （MHD） duct flow and some ab- normal phenomena deviating from the classical MHD laws were measured in an experimental investigation of the MHD effect of the flow channel inserter （FCI） duct flow. The results showed that the velocity distribution deviated from the M-type profile on the centre-plane of the cross section of the duct with small slots （in short ＂S-duct＂）. The electric potential difference in the duct wall was much lower than that given by the classical electromagnetic laws. The MHD pres- sure drop was much higher than that from the classical magneto-hydrodynamics theory. These results may help us find some new methods to reduce the MHD pressure drop, or explore other potential applications such as flow structure control.展开更多
Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sen...Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sensitive male sterile line (Peiai 64S) of rice were studied using immunofluorescence confocal microscopy. In IR36, from pre-meiotic interphase to metaphase I, the pattern of microtubule distribution in the meiocytes underwent a series of changes. Some new organizational patterns of microtubules (that have not been described before) were observed during microsporogenesis, including the existence of a broad band of perinuclear microtubules at the diakinesis stage of development. The pattern of microtubule distribution in the meiocytes of the male sterile line, Peiai 64S, was quite different front that seen in IR36. In Peiai 64S, the microtubules showed abnormal patterns of distribution from pre-meiotic interphase to metaphase I. For example the broad band of perinuclear microtubules seen at diakinesis in IR36 was much disorganized and loosened in Peiai 64S. The spindles formed were also very abnormal and different from the normal spindle. The appearance of abnormal microtubule distribution in the early stages of microsporogenesis may contribute to the malformation and ultimate abortion of pollen in Peiai 64S.展开更多
文摘Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.
基金The authors gratefully acknowledge the finical support of the National Key Research and Development Project(No.2017YFB0310600)this work is also supported by Shanghai International Science and Technology Cooperation Fund(Nos.17520711700 and 18520744200).
文摘The outbreak of coronavirus disease 2019 has seriously threatened human health.Rapidly and sensitively detecting SARSCoV-2 viruses can help control the spread of viruses.However,it is an arduous challenge to apply semiconductor-based substrates for virus SERS detection due to their poor sensitivity.Therefore,it is worthwhile to search novel semiconductor-based substrates with excellent SERS sensitivity.Herein we report,for the first time,Nb2C and Ta2C MXenes exhibit a remarkable SERS enhancement,which is synergistically enabled by the charge transfer resonance enhancement and electromagnetic enhancement.Their SERS sensitivity is optimized to 3.0×10^6 and 1.4×10^6 under the optimal resonance excitation wavelength of 532 nm.Additionally,remarkable SERS sensitivity endows Ta2C MXenes with capability to sensitively detect and accurately identify the SARS-CoV-2 spike protein.Moreover,its detection limit is as low as 5×10^−9 M,which is beneficial to achieve real-time monitoring and early warning of novel coronavirus.This research not only provides helpful theoretical guidance for exploring other novel SERS-active semiconductor-based materials but also provides a potential candidate for the practical applications of SERS technology.
基金supported by the Air Force Office of Scientific Research(Grant FA8650-19-C-2207)。
文摘Sensitivity analysis in chaotic dynamical systems is a challenging task from a computational point of view.In this work,we present a numerical investigation of a novel approach,known as the space-split sensitivity or S3 algorithm.The S3 algorithm is an ergodic-averaging method to differentiate statistics in ergodic,chaotic systems,rigorously based on the theory of hyperbolic dynamics.We illustrate S3 on one-dimensional chaotic maps,revealing its computational advantage over na?ve finite difference computations of the same statistical response.In addition,we provide an intuitive explanation of the key components of the S3 algorithm,including the density gradient function.
基金National Natural Science Foundation of China(No.71071159)
文摘A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phased mission systems( PMS). The simulation strategy of GMS based on a Petri net and Monte Carlo method was presented which had broad applicability. Finally,the GMS and Birnbaum's sensitivity of components in a PMS example were compared. The GMS of component is demonstrated to be more adaptable to reflect the component mission sensitivity when the rated reliability parameters of components cannot be obtained, and components have state dependency or the system is subjected to common cause failure.
文摘BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant biliary tract cancer with poor prognosis.Previous studies have implicated the gut microbiota in CCA,but evidence for causal mechanisms is lacking.AIM To investigate the causal relationship between gut microbiota and CCA risk.METHODS We performed a two-sample mendelian randomization study to evaluate potential causal associations between gut microbiota and CCA risk using genome-wide association study summary statistics for 196 gut microbial taxa and CCA.Genetic variants were used as instrumental variables.Multiple sensitivity analyses assessed result robustness.RESULTS Fifteen gut microbial taxa showed significant causal associations with CCA risk.Higher genetically predicted abundance of genus Eubacteriumnodatum group,genus Ruminococcustorques group,genus Coprococcus,genus Dorea,and phylum Actinobacteria were associated with reduced risk of gallbladder cancer and extrahepatic CCA.Increased intrahepatic CCA risk was associated with higher abundance of family Veillonellaceae,genus Alistipes,order Enterobacteriales,and phylum Firmicutes.Protective effects against CCA were suggested for genus Collinsella,genus Eisenbergiella,genus Anaerostipes,genus Paraprevotella,genus Parasutterella,and phylum Verrucomicrobia.Sensitivity analyses indicated these findings were reliable without pleiotropy.CONCLUSION This pioneering study provides novel evidence that specific gut microbiota may play causal roles in CCA risk.Further experimental validation of these candidate microbes is warranted to consolidate causality and mechanisms.
基金Supported by "Hertha Christensens Fond" and "The Danish Agency for Science, Technology and Innovation"
文摘AIM: To investigate sensations to multimodal pain stimulation in the metaplastic and normal parts of the esophagus in patients with Barrett’s esophagus (BE). METHODS: Fifteen patients with BE and 15 age-matched healthy volunteers were subjected to mechanical, thermal and electrical pain stimuli of the esophagus. Both the metaplastic part and the normal part (4 and 14 cm, respectively, above the esophago-gastric junction) were examined. At sensory thresholds the stimulation intensity, referred pain areas, and evoked brain potentials were recorded. RESULTS: Patients were hyposensitive to heat stimulation both in the metaplastic part [median stimulation time to reach the pain detection threshold: 15 (12-34) s vs 14 (6-23) s in controls; F = 4.5, P = 0.04] and the normal part of the esophagus [median 17 (6-32) s vs 13 (8-20) s in controls; F = 6.2, P = 0.02]. Furthermore, patients were hyposensitive in the metaplastic part of the esophagus to mechanical distension [median volume at moderate pain: 50 (20-50) mL vs 33 (13-50) mL in controls; F = 5.7, P = 0.02]. No indication of central nervous system abnormalities was present, as responses were comparable between groups to electrical pain stimuli in the metaplastic part [median current evoking moderate pain: 13 (6-26) mA vs 12 (9-24) mA in controls; F = 0.1, P = 0.7], and in the normal part of the esophagus [median current evoking moderate pain: 9 (6-16) mA, vs 11 (5-11) mA in controls; F = 3.4, P = 0.07]. Furthermore, no differences were seen for the referred pain areas (P-values all > 0.3) or latencies and amplitudes for the evoked brain potentials (P-values all > 0.1). CONCLUSION: Patients with BE are hyposensitive both in the metaplastic and normal part of esophagus likely as a result of abnormalities affecting peripheral nerve pathways.
文摘Compared with the conventionally used i=iosinωt alternating current, using asymmetric triangular and pulse wave as input signals can greatly enhance the incision's sensitivity of 'dE/dt-E'oscillogram.
基金supported by National Natural Science Foundation of China (No.10775042)
文摘Geometry sensitivity of magnetohydrodynamics （MHD） duct flow and some ab- normal phenomena deviating from the classical MHD laws were measured in an experimental investigation of the MHD effect of the flow channel inserter （FCI） duct flow. The results showed that the velocity distribution deviated from the M-type profile on the centre-plane of the cross section of the duct with small slots （in short ＂S-duct＂）. The electric potential difference in the duct wall was much lower than that given by the classical electromagnetic laws. The MHD pres- sure drop was much higher than that from the classical magneto-hydrodynamics theory. These results may help us find some new methods to reduce the MHD pressure drop, or explore other potential applications such as flow structure control.
文摘Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sensitive male sterile line (Peiai 64S) of rice were studied using immunofluorescence confocal microscopy. In IR36, from pre-meiotic interphase to metaphase I, the pattern of microtubule distribution in the meiocytes underwent a series of changes. Some new organizational patterns of microtubules (that have not been described before) were observed during microsporogenesis, including the existence of a broad band of perinuclear microtubules at the diakinesis stage of development. The pattern of microtubule distribution in the meiocytes of the male sterile line, Peiai 64S, was quite different front that seen in IR36. In Peiai 64S, the microtubules showed abnormal patterns of distribution from pre-meiotic interphase to metaphase I. For example the broad band of perinuclear microtubules seen at diakinesis in IR36 was much disorganized and loosened in Peiai 64S. The spindles formed were also very abnormal and different from the normal spindle. The appearance of abnormal microtubule distribution in the early stages of microsporogenesis may contribute to the malformation and ultimate abortion of pollen in Peiai 64S.
