Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net...Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net network based on a communication mechanism is introduced into a deep reinforcement learning algorithm to solve the multi-agent problem. A layer of gated recurrent unit(GRU) is added to the actor-network structure to remember historical environmental states. Subsequently,another GRU is designed as a communication channel in the Comm Net core network layer to refine communication information between UAVs. Finally, the simulation results of the algorithm in two sets of scenarios are given, and the results show that the method has good effectiveness and applicability.展开更多
The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn c...The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn catalyst to overcome the limit of electron transfer and CO_(2) adsorption capacity of Sn.Hierarchically porous structure of Sn doped carbonized ZIF-8 is controlled by hydrothermal and carbonization conditions,which induces much higher specific surface area than that of the commercial Sn nanoparticle(1003.174 vs.7.410 m^(2)·g^(-1)).The shift of nitrogen peaks in X-ray Photoelectron Spectroscopy spectra indicates interaction between ZIF-8 and Sn,which induces the shift of electron cloud from Sn to the chemical nitrogen to enhance conductivity and regulate electron transfer from catalyst to CO_(2).Lower mass transfer resistance and Warburg resistance are investigated through EIS,which significantly improves the catalytic activity for CO_(2) reduction reaction(CO_(2)RR).Onset potential of the reaction is reduced from-0.74 V to less than-0.54 V vs.RHE.The total Faraday efficiency of HCOOH and CO reaches 68.9%at-1.14 V vs.RHE,which is much higher than that of the commercial Sn(45.0%)and some other Sn-based catalyst reported in the literature.展开更多
Background and Aims:Hepatitis delta virus(HDV)is a defective virus and causes severe liver disease.Several HDV RNA assays have been developed,however the diagnostic efficacy remains unclear.This systematic review and ...Background and Aims:Hepatitis delta virus(HDV)is a defective virus and causes severe liver disease.Several HDV RNA assays have been developed,however the diagnostic efficacy remains unclear.This systematic review and metaanalysis aims to evaluate the diagnostic accuracy of HDV RNA assays to aid in the diagnosis of active hepatitis D.Methods:The PubMed,Embase,and Cochrane Library databases were systematically searched from the beginning to June 31,2022.Information on the characteristics of the literature and data on sensitivity,specificity,and area under curve(AUC)of the receiver operating characteristic(ROC)were extracted.Stata 14.0 was used for meta-analysis of the combined sensitivity,specificity,positive likelihood ratio,and negative likelihood ratio.Results:A total of 10 studies were included in the meta-analysis.The summary sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,and diagnostic odds ratio of HDV RNA assays for HDV diagnosis were 0.92(95%CI:0.87-0.95),0.90(95%CI:0.86-0.93),7.74(95%CI:5.31-11.29),0.10(95%CI:0.06-0.18)and 99.90(95%CI:47.08-211.99),respectively.The AUC of the pooled ROC curve was 0.95(95%CI:0.92-0.96).Conclusions:The results show that HDV RNA assays had high diagnostic performance.However,that is limited by the number and quality of studies.Standard protocols for the development of assays by manufacturers and larger studies on the use of the assays are needed.展开更多
Objective Decline, disruption, or alterations of nicotinic cholinergic mechanisms contribute to cognitive dysfunctions like Alzheimer's disease (AD). Although amyloid-β (Aβ) aggregation is a pathological hallma...Objective Decline, disruption, or alterations of nicotinic cholinergic mechanisms contribute to cognitive dysfunctions like Alzheimer's disease (AD). Although amyloid-β (Aβ) aggregation is a pathological hallmark of AD, the mechanisms by which Aβ peptides modulate cholinergic synaptic transmission and memory loss remain obscure. This study was aimed to investigate the potential synaptic modulation by Aβ of the cholinergic synapses between olfactory receptor neurons and projection neurons (PNs) in the olfactory lobe of the fruit fly. Methods Cholinergic spontaneous and miniature excitatory postsynaptic current (mEPSC) were recorded with whole-cell patch clamp from PNs in Drosophila AD models expressing Aβ40, Aβ42, or Aβ42Arc peptides in neural tissue. Results In fly pupae (2 days before eclosion), overexpression of Aβ42 or Aβ42Arc, but not Aβ40, led to a significant decrease of mEPSC frequency, while overexpression of Aβ40, Aβ42, or Aβ42Arc had no significant effect on mEPSC amplitude. In contrast, Pavlovian olfactory associative learning and lifespan assays showed that both short-term memory and lifespan were decreased in the Drosophila models expressing Aβ40, Aβ42, or Aβ42Arc. Conclusion Both electrophysiological and behavioral results showed an effect of Aβ peptide on cholinergic synaptic transmission and suggest a possible mechanism by which Aβ peptides cause cholinergic neuron degeneration and the consequent memory loss.展开更多
基金supported in part by the National Key Laboratory of Air-based Information Perception and Fusion and the Aeronautical Science Foundation of China (Grant No. 20220001068001)National Natural Science Foundation of China (Grant No.61673327)+1 种基金Natural Science Basic Research Plan in Shaanxi Province,China (Grant No. 2023-JC-QN-0733)China IndustryUniversity-Research Innovation Foundation (Grant No. 2022IT188)。
文摘Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net network based on a communication mechanism is introduced into a deep reinforcement learning algorithm to solve the multi-agent problem. A layer of gated recurrent unit(GRU) is added to the actor-network structure to remember historical environmental states. Subsequently,another GRU is designed as a communication channel in the Comm Net core network layer to refine communication information between UAVs. Finally, the simulation results of the algorithm in two sets of scenarios are given, and the results show that the method has good effectiveness and applicability.
基金the National Natural Science Foundation of China(Joint Fund U1663223 and 21776034)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)+3 种基金the National Key Research and Development Program of China(2016YFB0101203)Educational Department of Liaoning Province of China(LT2015007)Fundamental Research Funds for the Central Universities(DUT16TD19)the Changjiang Scholar Program(T2012049).
文摘The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn catalyst to overcome the limit of electron transfer and CO_(2) adsorption capacity of Sn.Hierarchically porous structure of Sn doped carbonized ZIF-8 is controlled by hydrothermal and carbonization conditions,which induces much higher specific surface area than that of the commercial Sn nanoparticle(1003.174 vs.7.410 m^(2)·g^(-1)).The shift of nitrogen peaks in X-ray Photoelectron Spectroscopy spectra indicates interaction between ZIF-8 and Sn,which induces the shift of electron cloud from Sn to the chemical nitrogen to enhance conductivity and regulate electron transfer from catalyst to CO_(2).Lower mass transfer resistance and Warburg resistance are investigated through EIS,which significantly improves the catalytic activity for CO_(2) reduction reaction(CO_(2)RR).Onset potential of the reaction is reduced from-0.74 V to less than-0.54 V vs.RHE.The total Faraday efficiency of HCOOH and CO reaches 68.9%at-1.14 V vs.RHE,which is much higher than that of the commercial Sn(45.0%)and some other Sn-based catalyst reported in the literature.
基金supported by National Natural Science Foundation of China(grant numbers 81770611,82002243,82100653)Key Projects of the Beijing Municipal Education Commission’s Science and Technology Plan(grant number KZ202010025035)+4 种基金Special Key Research Project of Capital Health Development Scientific Research(grant numbers SF2020-1-1151,SF2021-1G-2181,SF2022-1-2182)Demonstrating Application and Research of Clinical Diagnosis and Treatment Technology in Beijing(grant numbers Z191100006619096,Z191100006619097)Beijing Talents Foundation(grant number 2018000021469G289)Beijing Hospitals Authority Youth Program(grant number QML20201702)Talent Cultivation Plan of“Climbing the Peak”of Beijing Municipal Hospital Administration(grant number DFL20221503).
文摘Background and Aims:Hepatitis delta virus(HDV)is a defective virus and causes severe liver disease.Several HDV RNA assays have been developed,however the diagnostic efficacy remains unclear.This systematic review and metaanalysis aims to evaluate the diagnostic accuracy of HDV RNA assays to aid in the diagnosis of active hepatitis D.Methods:The PubMed,Embase,and Cochrane Library databases were systematically searched from the beginning to June 31,2022.Information on the characteristics of the literature and data on sensitivity,specificity,and area under curve(AUC)of the receiver operating characteristic(ROC)were extracted.Stata 14.0 was used for meta-analysis of the combined sensitivity,specificity,positive likelihood ratio,and negative likelihood ratio.Results:A total of 10 studies were included in the meta-analysis.The summary sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,and diagnostic odds ratio of HDV RNA assays for HDV diagnosis were 0.92(95%CI:0.87-0.95),0.90(95%CI:0.86-0.93),7.74(95%CI:5.31-11.29),0.10(95%CI:0.06-0.18)and 99.90(95%CI:47.08-211.99),respectively.The AUC of the pooled ROC curve was 0.95(95%CI:0.92-0.96).Conclusions:The results show that HDV RNA assays had high diagnostic performance.However,that is limited by the number and quality of studies.Standard protocols for the development of assays by manufacturers and larger studies on the use of the assays are needed.
基金supported by grants from the Department of Health of Heilongjiang Province, China (2006-228)the Educational Commission of Heilongjiang Province, China(11531096)+2 种基金the National Natural Science Foundation of China (31100819, 30970980)the Natural Science Foundation of Guangdong Province, China (S2011040002239)the China Postdoctoral Science Foundation (2010-0480805)
文摘Objective Decline, disruption, or alterations of nicotinic cholinergic mechanisms contribute to cognitive dysfunctions like Alzheimer's disease (AD). Although amyloid-β (Aβ) aggregation is a pathological hallmark of AD, the mechanisms by which Aβ peptides modulate cholinergic synaptic transmission and memory loss remain obscure. This study was aimed to investigate the potential synaptic modulation by Aβ of the cholinergic synapses between olfactory receptor neurons and projection neurons (PNs) in the olfactory lobe of the fruit fly. Methods Cholinergic spontaneous and miniature excitatory postsynaptic current (mEPSC) were recorded with whole-cell patch clamp from PNs in Drosophila AD models expressing Aβ40, Aβ42, or Aβ42Arc peptides in neural tissue. Results In fly pupae (2 days before eclosion), overexpression of Aβ42 or Aβ42Arc, but not Aβ40, led to a significant decrease of mEPSC frequency, while overexpression of Aβ40, Aβ42, or Aβ42Arc had no significant effect on mEPSC amplitude. In contrast, Pavlovian olfactory associative learning and lifespan assays showed that both short-term memory and lifespan were decreased in the Drosophila models expressing Aβ40, Aβ42, or Aβ42Arc. Conclusion Both electrophysiological and behavioral results showed an effect of Aβ peptide on cholinergic synaptic transmission and suggest a possible mechanism by which Aβ peptides cause cholinergic neuron degeneration and the consequent memory loss.