A Localization Method of High Energy Transients for All-sky Gamma-ray Monitor

Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.

Clinical Study on the Treatment of Low Anal Fistula in Infants and Young Children by Anal Gland Excision and Virtual Hanging Procedure

Objective:To compare the efficacy of anal adenectomy with virtual hanging wire and anal fistulotomy in the treatment of low anal fistula in infants and children.Methods:60 children with low anal fistula who were admitted to our hospital from October 2021 to March 2022 and met the inclusion criteria were randomly divided into two groups of 30 cases each;the treatment group was treated with anal adenectomy and virtual hanging wire surgery,and the control group was treated with anal fistula resection.The clinical efficacy after treatment was compared.Results:The total effective rate of both groups was 96.67%and the difference between the two groups was not statistically significant(P>0.05).The postoperative pain score of the treatment group was lower than that of the control group(P<0.05).The length of hospitalization and healing time of the treatment group was lower than that of the control group(P<0.05).The anal function of the patients in both groups was normal,and there was no adverse reaction.Conclusion:Anal gland excision and virtual hanging surgery for the treatment of low anal fistula in infants and children have the advantages of mild pain,reduced length of hospitalization,short healing time,and better patient experience as compared to anal fistula excision.

Efficient Group Blind Signature for Medical Data Anonymous Authentication in Blockchain-Enabled IoMT

Blockchain technology promotes the development of the Internet of medical things(IoMT)from the centralized form to distributed trust mode as blockchain-based Internet of medical things(BIoMT).Although blockchain improves the cross-institution data sharing ability,there still exist the problems of authentication difficulty and privacy leakage.This paper first describes the architecture of the BIoMT system and designs an anonymous authentication model for medical data sharing.This BIoMT system is divided into four layers:perceptual,network,platform,and application.The model integrates an anonymous authentication scheme to guarantee secure data sharing in the network ledger.Utilizing the untampered blockchain ledger can protect the privacy of medical data and system users.Then,an anonymous authentication scheme called the group blind signature(GBS)scheme is designed.This scheme can provide anonymity for the signer as that one member can represent the group to sign without exposing his identity.The blind property also can protect the message from being signed as it is anonymous to the signer.More-over,this GBS scheme is created with the lattice assumption,which makes it more secure against quantum attacks.In addition,the security proof shows that this GBS scheme can achieve the security properties of dynamical-almost-full anonymity,blindness,traceability,and non-frameability.The comparison analysis and performance evaluation of key size show that this GBS scheme is more efficient than similar schemes in other literature.

The Design of GECAM Scientific Ground Segment

The Gravitational wave burst high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)is a dedicated mission for monitoring high-energy transients.Here we report the design of the GECAM Scientific Ground Segment(GSGS)in terms of the scientific requirements,including the architecture,the external interfaces,the main function,and workflow.Judging from the analysis and verification results during the commissioning phase,the GSGS functions well and is able to monitor the status of the payloads,adjust the parameters,develop the scientific observation plans,generate the scientific data products,analyze the data,etc.Thus,the on-orbit operation and scientific researches of GECAM are guaranteed.

A New Anti-Quantum Proxy Blind Signature for Blockchain-Enabled Internet of Things

Blockchain technology has become a research hotspot in recent years with the prominent characteristics as public,distributed and decentration.And blockchain-enabled internet of things(BIoT)has a tendency to make a revolutionary change for the internet of things(IoT)which requires distributed trustless consensus.However,the scalability and security issues become particularly important with the dramatically increasing number of IoT devices.Especially,with the development of quantum computing,many extant cryptographic algorithms applied in blockchain or BIoT systems are vulnerable to the quantum attacks.In this paper,an anti-quantum proxy blind signature scheme based on the lattice cryptography has been proposed,which can provide user anonymity and untraceability in the distributed applications of BIoT.Then,the security proof of the proposed scheme can derive that it is secure in random oracle model,and the efficiency analysis can indicate it is efficient than other similar literatures.

A panel of monoclonal antibodies against the prion protein proves that there is no prion protein in human pancreatic ductal epithelial cells

Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay(ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells(HPDC).

Stackelberg Game-Based Resource Allocation with Blockchain for Cold-Chain Logistics System

Cold-chain logistics system(CCLS)plays the role of collecting and managing the logistics data of frozen food.However,there always exist problems of information loss,data tampering,and privacy leakage in traditional centralized systems,which influence frozen food security and people’s health.The centralized management form impedes the development of the cold-chain logistics industry and weakens logistics data availability.This paper first introduces a distributed CCLS based on blockchain technology to solve the centralized management problem.This system aggregates the production base,storage,transport,detection,processing,and consumer to form a cold-chain logistics union.The blockchain ledger guarantees that the logistics data cannot be tampered with and establishes a traceability mechanism for food safety incidents.Meanwhile,to improve the value of logistics data,a Stackelberg game-based resource allocation model has been proposed between the logistics data resource provider and the consumer.The competition between resource price and volume balances the resource supplement and consumption.This model can help to achieve an optimal resource price when the Stackelberg game obtains Nash equilibrium.The two participants also can maximize their revenues with the optimal resource price and volume by utilizing the backward induction method.Then,the performance evaluations of transaction throughput and latency show that the proposed distributed CCLS is more secure and stable.The simulations about the variation trend of data price and amount,optimal benefits,and total benefits comparison of different forms show that the resource allocation model is more efficient and practical.Moreover,the blockchain-based CCLS and Stackelberg game-based resource allocation model also can promote the value of logistic data and improve social benefits.

Efficient Certificateless Authenticated Key Agreement for Blockchain-Enabled Internet of Medical Things

Internet of Medical Things(IoMT)plays an essential role in collecting and managing personal medical data.In recent years,blockchain technology has put power in traditional IoMT systems for data sharing between different medical institutions and improved the utilization of medical data.However,some problems in the information transfer process between wireless medical devices and mobile medical apps,such as information leakage and privacy disclosure.This paper first designs a cross-device key agreement model for blockchain-enabled IoMT.This model can establish a key agreement mechanism for secure medical data sharing.Meanwhile,a certificateless authenticated key agreement(KA)protocol has been proposed to strengthen the information transfer security in the cross-device key agreement model.The proposed KA protocol only requires one exchange of messages between the two parties,which can improve the protocol execution efficiency.Then,any unauthorized tampering of the transmitted signed message sent by the sender can be detected by the receiver,so this can guarantee the success of the establishment of a session key between the strange entities.The blockchain ledger can ensure that the medical data cannot be tampered with,and the certificateless mechanism can weaken the key escrow problem.Moreover,the security proof and performance analysis are given,which show that the proposed model and KA protocol are more secure and efficient than other schemes in similar literature.

Quantum Secure Undeniable Signature for Blockchain-Enabled Cold-Chain Logistics System

Data security and user privacy are two main security concerns in the cold-chain logistics system(CCLS).Many security issues exist in traditional CCLS,destroying data security and user privacy.The digital signature can provide data verification and identity authentication based on the mathematical difficulty problem for logistics data sharing in CCLS.This paper first established a blockchain-enabled cold-chain logistics system(BCCLS)based on union blockchain technology,which can provide secure data sharing among different logistics nodes and guarantee logistics data security with the untampered blockchain ledger.Meanwhile,a lattice-based undeniable signature scheme is designed to strengthen the security of logistics data and user privacy against quantum attacks.This scheme is based on the lattice assumption,which can provide anti-quantum security for BCCLS in the future quantum computer age.It also establishes the undeniable mechanism that guarantees that the actual signer cannot deny a valid signature.Then,security proof shows that this undeniable signature scheme is correct and safe,and an efficiency comparison shows that it is more efficient than other schemes in similar literature.The performance evaluations of transaction throughput and latency show that the proposed BCCLS is efficient and practical.This work can improve the security and efficiency of logistics data management and promote the reform and development of the logistics industry.

Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal gait.To assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb exoskeletons.The control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference trajectory.Long Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase information.In the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary leg.In addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral gaits.The LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,respectively.To further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric gait.From the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.

Research on Prefabricated Open Caisson Construction Technology

With the continuous improvement of urban residents’lives,the demand for of urban infrastructure construction increases,requiring more and more advanced engineering technology.We should not only speed up the progress of the project,but also reduce the impact of the construction on the surrounding environment.Our company has had several achievements in this regard,and prefabricated open caisson construction process is one of them.In this paper,the application of prefabricated caisson construction method is analyzed in depth according to the actual situation of the rain sewage reconstruction treatment project of Minghe ecological water system in Dancheng County.Through practice,it is concluded that this construction method greatly improves the construction efficiency,shortens the overall construction process,reduces the construction cost,and effectively improves environmental quality of the construction site,which has good reference value.

Space-resolved vacuum-ultraviolet spectroscopy for measuring impurity emission from divertor region of EAST tokamak

The measurement of impurity distribution in the divertor region of tokamaks is key to studying edge impurity transport.Therefore,a space-resolved vacuum-ultraviolet(VUV)spectrometer is designed to measure impurity emission in the divertor region on EAST.For good spectral resolution,an eagle-type VUV spectrometer with 1 m long focal length with spherical holograph grating is used in the system.For light collection,a collimating mirror is installed between the EAST plasma and the VUV spectrometer to extend the observing range to cover the upper divertor region.Two types of detectors,i.e.a back-illuminated charge-coupled device detector and a photomultiplier-tube detector,are adopted for the spectral measurement and high-frequency intensity measurement for feedback control,respectively.The angle between the entrance and exit optical axis is fixed at 15°.The detector can be moved along the exit axis to maintain a good focusing position when the wavelength is scanned by rotating the grating.The profile of impurity emissions is projected through the space-resolved slit,which is set horizontally.The spectrometer is equipped with two gratings with 2400 grooves/mm and2160 grooves/mm,respectively.The overall aberration of the system is reduced by accurate detector positioning.As a result,the total spectral broadening can be reduced to about 0.013 nm.The simulated performance of the system is found to satisfy the requirement of measurement of impurity emissions from the divertor area of the EAST tokamak.

Intrapulse coherence degradation suppressing method of echo signal in coherent lidar

Aiming at coherence degradation during target detection,a suppressing method based on frequency-modulated continuous wave coherent lidar is proposed.Combined with a random iteration algorithm,a long-pulse echo signal with coherent degradation is matched with random phase noise of a certain frequency and achieves coherence restoration.Simulation and field experiment results show that this proposed method can recover the intrapulse coherence in long-pulse echo signals.In addition,for the real target echo signal at 4.2 and 19.8 km,the peak signal-to-noise ratio processed by this method is increased by 0.35 times and 4 times after pulse compression,respectively.

Data Anonymous Authentication for BIoMT with Proxy Group Signature

Along with the increase of wearable medical device,the privacy leakage problem in the process of transmission between these edge medical devices.The blockchain-enabled Internet of Medical Things(BIoMT)has been developed to reform traditional centralized medical system in recent years.This paper first introduces a data anonymous authentication model to protect user privacy and medical data in BIoMT.Then,a proxy group signature(PGS)scheme has been proposed based on lattice assumption.This scheme can well satisfy the anonymous authentication demand for the proposed model,and provide anti-quantum attack security for BIoMT in the future general quantum computer age.Moreover,the security analysis shows this PGS scheme is secure against the dynamical-almost-full anonymous and traceability.The efficiency comparison shows the proposed model and PGS scheme is more efficient and practical.

Binding between Prion Protein and Aβ Oligomers Contributes to the Pathogenesis of Alzheimer’s Disease

A plethora of evidence suggests that protein misfolding and aggregation are underlying mechanisms of various neurodegenerative diseases,such as prion diseases and Alzheimer's disease(AD).Like prion diseases,AD has been considered as an infectious disease in the past decades as it shows strain specificity and transmission potential.Although it remains elusive how protein aggregation leads to AD,it is becoming clear that cellular prion protein(PrP^c)plays an important role in AD pathogenesis.Here,we briefly reviewed AD pathogenesis and focused on recent progresses how PrP^c contributed to AD development.In addition,we proposed a potential mechanism to explain why infectious agents,such as viruses,conduce AD pathogenesis.Microbe infections cause AD deposition and upregulation of PrP^c,which lead to high affinity binding between AD oligomers and PrP^c.The interaction between PrP^c and AP oligomers in turn activates the Fyn signaling cascade,resulting in neuron death in the central nervous system(CNS).Thus,silencing PrP^c expression may turn out be an effective treatment for PrP^c dependent AD.

Hepatitis C virus-induced prion protein expression facilitates hepatitis C virus replication

Hepatitis C virus(HCV) infects approximately 180 million people worldwide. Significant progress has been made since the establishment of in vitro HCV infection models in cells. However, the replication of HCV is complex and not completely understood. Here, we found that the expression of host prion protein(Pr P) was induced in an HCV replication cell model. We then showed that increased Pr P expression facilitated HCV genomic replication. Finally, we demonstrated that the KKRPK motif on the N-terminus of Pr P bound nucleic acids and facilitated HCV genomic replication. Our results provided important insights into how viruses may harness cellular protein to achieve propagation.

Weak measurement of the magneto-optical spin Hall effect of light

The spin Hall effect of light(SHEL) is a photonic version of the spin Hall effect in electronic systems and has been studied for more than 10 years. However, the lack of effective methods for dynamic modulation of spin-dependent splitting may hinder its applications. By introducing additional spin-orbit coupling of photons or nonreciprocal phase shift(NRPS), the magneto-optical Kerr effect may be one of the methods to alleviate the situation. Here, we experimentally reveal an enhanced and tunable SHEL in magneto-optical oxide thin films under the transverse magneto-optical Kerr effect configuration for the first time, to the best of our knowledge, which can be regarded as the magneto-optical SHEL(MOSHEL). We study the magneto-optical response of the multilayer structure and select the optimal structural parameters by the magneto-optical transfer matrix method. With a transverse magnetic field along opposite directions, an obvious SHEL shift difference of H-polarized light caused by NRPS is observed via a weak measurement method. With optimal parameters, the maximum measured shift difference of the SHEL achieves about 70 μm. The demonstrated MOSHEL phenomenon may accelerate the application of the SHEL in the field of spin photonics devices and precision metrology.

Result of proton beam energy calibration of GECAM satellite charged particle detector

Purpose A charged particle detector(CPD)is one of two main detectors on the GECAM satellite.It was designed to detect charged particles.Electrons and protons are space’s mainly charged particles.So,a research on the proton detection ability of a CPD and deriving the energy response to charged particles of the CPD in the two designed operating modes is important.Method The proton calibration tests of the CPD under diferent working modes were carried out at the Heavy Ion Research Facility in Lanzhou.Result and conclusion Through testing and analysis,it was concluded that when CPD works in semi-component mode,it can detect the maximum energy,and when working in full-component mode,it can provide better energy resolution.

Microwave-assisted hydrothermal synthesis of Pt/SnO2 gas sensor for CO detection

In this paper,the Pt/SnO2 nanostructures were prepared via a facile one-step microwave assisted hydrothermal route.The structure of the introduced Pt/SnO2 and its gas-sensing properties toward CO were investigated.The results from the TEM test reveal that Pt grows on the SnO2 nanostructure,which was not found for bulk in this situ method,constructing Pt/SnO2.The results indicated that the sensor using 3.0 wt%Pt/SnO2 to 100 ppm carbon monoxide performed a superior sensing properties compared to 1.5 wt%and 4.5 wt%Pt/SnO2 at 225℃.The response time of 3.0 wt%sensor is 16 s to 100 ppm CO at225℃.Such enhanced gas sensing performances could be attributed to the chemical and electrical factors.In view of chemical factors,the presence of Pt facilitates the surface reaction,which will improve the gas sensing properties.With respect to the electrical factors,the Pt/SnO2 plays roles in increasing the sensor’s response due to its characteristic configuration.In addition,the one-step in situ microwave assisted process provides a promising and versatile choice for the preparation of gas sensing materials.