In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization n...In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel,but also reduce the noise introduced by phase interference.However,arbitrary continuous modulation can not be carried out in the past polarization coding,resulting in that the signal state can not obtain arbitrary continuous value in Poincare space,and the security analysis of CV-QKD using polarized coherent-states in free space is not complete.Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller.In particular,in terms of the main influence factors in the free-space channel,we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate.In addition,the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather.Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather.The protocol fails when visibility is less than 1 km.At the same time,the wavelength can affect the performance of the proposed scheme.Specifically,under foggy weather,the longer the wavelength,the smaller the attenuation coefficient,and the better the transmission performance.Our proposed scheme can expand the modulation range of signal state,and supplement the security research of the scheme in the free-space channel,thus can provide theoretical support for subsequent experiments.展开更多
[Objectives]To analyze the gene structure of the protein that predicts 6-hydroxymellein synthase of Aspergillus terreus and predict the characteristics and functions of the protein structure encoded by the gene.[Metho...[Objectives]To analyze the gene structure of the protein that predicts 6-hydroxymellein synthase of Aspergillus terreus and predict the characteristics and functions of the protein structure encoded by the gene.[Methods]Various information analysis tools in NCBI,CBS and ExPASy websites were adopted.[Results]The QODIPO gene had a full length of 2954 bp,with 952 amino acids in the coding area,and QODIPO had the highest homology with the hypothetical protein ATETN484_0003008800.The molecular weight of QOD1PO protein was 105040.56,the theoretical isoelectric point(pl)was 5.69 and the grand average of hydropathieity was-0.242.It was speculated that QODIPO was an unstable and non-secretory hydrophilic protein located in cytoplasm without transmembrane domain or signal peptide.It could be predicted that the secondary structure of QODIPO encoding protein consisted mainly of random coil,α-helix and a PKS-DH anhydrase domain.[Conclusions]The results will lay a theoretical foundation for cloning and expression of 6-hydroxymellein synthase and further understanding of its activity and function.展开更多
Simultaneously improving the energy density and power density of electrochemical energy storage systems is the ultimate goal of electrochemical energy storage technology.An effective strategy to achieve this goal is t...Simultaneously improving the energy density and power density of electrochemical energy storage systems is the ultimate goal of electrochemical energy storage technology.An effective strategy to achieve this goal is to take advantage of the high capacity and rapid kinetics of electrochemical proton storage to break through the power limit of batteries and the energy limit of capacitors.This article aims to review the research progress on the physicochemical properties,electrochemical performance,and reaction mechanisms of electrode materials for electrochemical proton storage.According to the different charge storage mechanisms,the surface redox,intercalation,and conversion materials are classified and introduced in detail,where the influence of crystal water and other nanostructures on the migration kinetics of protons is clarified.Several reported advanced full cell devices are summarized to promote the commercialization of electrochemical proton storage.Finally,this review provides a framework for research directions of charge storage mechanism,basic principles of material structure design,construction strategies of full cell device,and goals of practical application for electrochemical proton storage.展开更多
In the post-Moore era,neuromorphic computing has been mainly focused on breaking the von Neumann bottlenecks.Memristors have been proposed as a key part of neuromorphic computing architectures,and can be used to emula...In the post-Moore era,neuromorphic computing has been mainly focused on breaking the von Neumann bottlenecks.Memristors have been proposed as a key part of neuromorphic computing architectures,and can be used to emulate the synaptic plasticities of the human brain.Ferroelectric memristors represent a breakthrough for memristive devices on account of their reliable nonvolatile storage,low write/read latency and tunable conductive states.However,among the reported ferroelectric memristors,the mechanisms of resistive switching are still under debate.In addition,there needs to be more research on emulation of the brain synapses using ferroelectric memristors.Herein,Cu/PbZr_(0.52)Ti_(0.48)O_(3)(PZT)/Pt ferroelectric memristors have been fabricated.The devices are able to realize the transformation from threshold switching behavior to resistive switching behavior.The synaptic plasticities,including excitatory post-synaptic current,paired-pulse facilitation,paired-pulse depression and spike time-dependent plasticity,have been mimicked by the PZT devices.Furthermore,the mechanisms of PZT devices have been investigated by first-principles calculations based on the interface barrier and conductive filament models.This work may contribute to the application of ferroelectric memristors in neuromorphic computing systems.展开更多
Answering reachability queries is one of the fundamental graph operations.Existing approaches either accelerate index construction by constructing an index that covers only partial reachability relationship,which may ...Answering reachability queries is one of the fundamental graph operations.Existing approaches either accelerate index construction by constructing an index that covers only partial reachability relationship,which may result in performing cost traversing operation when answering a query;or accelerate query answering by constructing an index covering the complete reachability relationship,which may be inefficient due to comparing the complete node labels.We propose a novel labeling scheme,which covers the complete reachability relationship,to accelerate reachability queries processing.The idea is to decompose the given directed acyclic graph(DAG)G into two subgraphs,G1 and G2.For G1,we propose to use topological labels consisting of two integers to answer all reachability queries.For G2,we construct 2-hop labels as existing methods do to answer queries that cannot be answered by topological labels.The benefits of our method lie in two aspects.On one hand,our method does not need to perform the cost traversing operation when answering queries.On the other hand,our method can quickly answer most queries in constant time without comparing the whole node labels.We confirm the efficiency of our approaches by extensive experimental studies using 20 real datasets.展开更多
High-precision time interval measurement is a fundamental technique in many advanced applications,including time and distance metrology,particle physics,and ultra-precision machining.However,many of these applications...High-precision time interval measurement is a fundamental technique in many advanced applications,including time and distance metrology,particle physics,and ultra-precision machining.However,many of these applications are confined by the imprecise time interval measurement of electrical signals,restricting the performance of the ultimate system to a few picoseconds,which limits ultrahigh precision applications.Here,we demonstrate an optical means for the time interval measurement of electrical signals that can successfully achieve femtosecond(fs)level precision.The setup is established using the optical frequency comb(OFC)based linear optical sampling(LOS)technique to realize timescale-stretched measurement.We achieve a measurement precision of 82 fs for a single LOS scan measurement and 3.05 fs for the 100-times average with post-processing,which is three orders of magnitude higher than the results of older electrical methods.The high-precision time interval measurement of electrical signals can substantially improve precision measurement technologies.展开更多
Encoding information using the topological charge of vortex beams has been proposed for optical communications. The conservation of the topological charge on propagation and the detection of the topological charge by ...Encoding information using the topological charge of vortex beams has been proposed for optical communications. The conservation of the topological charge on propagation and the detection of the topological charge by a receiver are significant in these applications and have been well established in free-space. However, when vortex beams enter a diffuser,the wavefront is distorted, leading to a challenge in the conservation and detection of the topological charge. Here, we present a technique to measure the value of the topological charge of a vortex beam obscured in the randomly scattered light. The results of the numerical simulations and experiments are presented and are in good agreement. In particular, only a single-shot measurement is required to detect the topological charge of vortex beams, indicating that the method is applicable to a dynamic diffuser.展开更多
In the practical continuous-variable quantum key distribution(CV-QKD)system,the postprocessing process,particularly the error correction part,significantly impacts the system performance.Multi-edge type low-density pa...In the practical continuous-variable quantum key distribution(CV-QKD)system,the postprocessing process,particularly the error correction part,significantly impacts the system performance.Multi-edge type low-density parity-check(MET-LDPC)codes are suitable for CV-QKD systems because of their Shannon-limit-approaching performance at a low signal-to-noise ratio(SNR).However,the process of designing a low-rate MET-LDPC code with good performance is extremely complicated.Thus,we introduce Raptor-like LDPC(RL-LDPC)codes into the CV-QKD system,exhibiting both the rate compatible property of the Raptor code and capacity-approaching performance of MET-LDPC codes.Moreover,this technique can significantly reduce the cost of constructing a new matrix.We design the RL-LDPC matrix with a code rate of 0.02 and easily and effectively adjust this rate from 0.016 to 0.034.Simulation results show that we can achieve more than 98%reconciliation efficiency in a range of code rate variation using only one RL-LDPC code that can support high-speed decoding with an SNR less than-16.45 d B.This code allows the system to maintain a high key extraction rate under various SNRs,paving the way for practical applications of CV-QKD systems with different transmission distances.展开更多
The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role ...The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role in maintaining feto-maternal tolerance,little is known about the role of MDSCs in pregnancies with intrauterine growth retardation(IUGR).Here,we reported that the activation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)during pregnancy was closely associated with fetal growth.In humans,class E scavenger receptor 1(SR-E1),a distinct marker for human PMN-MDSCs,was used to investigate PMN-MDSC function during pregnancy.Continuous activation of SR-E1+PMN-MDSCs was observed in all stages of pregnancy,accompanied by high cellular levels of ROS and arginase-1 activity,mediated through STAT6 signaling.However,SR-E1+PMN-MDSCs in pregnancies with IUGR showed significantly lower suppressive activity,lower arginase-1 activity and ROS levels,and decreased STAT6 phosphorylation level,which were accompanied by an increase in inflammatory factors,compared with those in normal pregnancies.Moreover,the population of SR-E1+PMN-MDSCs was negatively correlated with the adverse outcomes of newborns from pregnancies with IUGR.In mice,decreases in cell population,suppressive activity,target expression levels,and STAT6 phosphorylation levels were also observed in the pregnancies with IUGR compared with the normal pregnancies,which were rescued by the adoptive transfer of PMN-MDSCs from pregnant mice.Interestingly,the growth-promoting factors(GPFs)secreted by placental PMN-MDSCs in both humans and mice play a vital role in fetal development.These findings collectively support that PMN-MDSCs have another new role in pregnancy,which can improve adverse neonatal outcomes.展开更多
Osteosarcoma is the most common primary malignant tumor of bone,particularly among children and adolescents.Advances in imaging,surgical techniques,and implants have dramatically reduced the need for amputation in the...Osteosarcoma is the most common primary malignant tumor of bone,particularly among children and adolescents.Advances in imaging,surgical techniques,and implants have dramatically reduced the need for amputation in the past three decades.Recently,in vivo fluorescence imaging in the second near-infrared window(NIR-II,1,000–1,700 nm)shows impressive advantages of deeper tissue penetration and higher spatial resolution,which makes it a promising tool for the early diagnosis and post-operative observation of Osteosarcoma.To the best of our knowledge,this paper is the first time to develop a novel NIR-II fluorescence probe conjugated with an osteosarcoma targeted oligopeptide for molecular tumor imaging in a xenograft orthotopic osteosarcoma mouse model.展开更多
The orbital angular momentum(OAM)of vortex beams offers a new degree for information encoding,which has been applied to optical communications.OAM measurement is essential for these applications,and has been realized ...The orbital angular momentum(OAM)of vortex beams offers a new degree for information encoding,which has been applied to optical communications.OAM measurement is essential for these applications,and has been realized in free space by several methods.However,these methods are inapplicable to estimate the OAM of vortex beams directly from the speckle patterns in the exit end of a multimode fiber(MMF).To tackle this issue,we design a convolutional neural network(CNN)to realize 100%accuracy recognition of two orthogonally polarized OAM modes from speckle patterns.Moreover,we demonstrate that even when the speckle patterns are cropped to only 1/64 of the original patterns,the recognition accuracy of the designed neural network is still higher than 98%.We also study the recognition accuracy of cropped speckles in different areas of speckle patterns to verify the feasibility of OAM recognition after cropping.The results demonstrate that recognizing the OAMs of two orthogonally polarized vortex beams from only a portion of speckle patterns in the exit end of an MMF is feasible,offering the potential to construct a 1×N data transmission scheme.展开更多
The intensity distributions of a high-power broadband laser beam passing through a nonlinear optical medium with defects and then propagating in free space are investigated based on the general nonlinear Schr¨odi...The intensity distributions of a high-power broadband laser beam passing through a nonlinear optical medium with defects and then propagating in free space are investigated based on the general nonlinear Schr¨odinger equation and the split-step Fourier numerical method. The influences of the bandwidth of the laser beam, the thickness of the medium,and the defects on the light intensity distribution are revealed. We find that the nonlinear optical effect can be suppressed and that the uniformity of the beam can be improved for a high-power broadband laser beam with appropriate wide bandwidth. It is also found that, under the same incident light intensity, a thicker medium will lead to a stronger self-focusing intensity, and that the influence of defects in the optical elements on the intensity is stronger for a narrowband beam than for a broadband beam.展开更多
The spatial rogue waves(RWs)generated by a wide Gaussian beam in a saturated nonlinear system are experimentally observed.Our observations show that RWs are most likely to occur when Gaussian light evolves to the crit...The spatial rogue waves(RWs)generated by a wide Gaussian beam in a saturated nonlinear system are experimentally observed.Our observations show that RWs are most likely to occur when Gaussian light evolves to the critical state of filament splitting,and then the probability of RWs decreases with voltage fluctuations.The occurrence probability of RWs after splitting is related to the nonlinear breathing phenomenon of optical filament,and the statistics of RWs satisfy the long-tailed L-shaped distribution.The experiment proves that the presence of high-frequency components and the aggregation of low-frequency components can serve as a prerequisite for the occurrence of extreme events(EEs).展开更多
文摘为了比较自动机器学习下不同机器学习模型预测部分猪生长性状与全基因组估计育种值(genomic estimated breeding value,GEBV)的性能,并寻找适合的机器学习模型,以优化生猪育种的全基因组评估方法,本研究利用来自多个公司9968头猪的基因组信息、系谱矩阵、固定效应及表型信息通过自动机器学习方法获取深度学习(deep learning,DL)、随机森林(random forest,RF)、梯度提升机(gradient boosting machine,GBM)和极致梯度提升(extreme gradient boosting,XGB)4种机器学习最佳模型。采用10折交叉验证分别对猪达100 kg校正背膘(correcting backfat to 100 kg,B100)、达115 kg校正背膘(correcting backfat to 115 kg,B115)、达100 kg校正日龄(correcting days to 100 kg,D100)、达115 kg校正日龄(correcting days to 100 kg,D115)的GEBV及其表型进行预测,比较不同机器学习模型应用于猪基因组评估的性能。结果表明:机器学习模型对GEBV的估计准确性高于性状表型;在GEBV预测中,GBM在B100、B115、D100、D115的预测准确性分别为0.683、0.710、0.866、0.871,略高于其他方法;在表型预测中,对猪B100、B115、D100、D115预测性能最好的模型依次为GBM(0.547)、DL(0.547)、XGB(0.672、0.670);在模型训练所需时间上,RF远高于其他3种模型,GBM与DL居中,XGB所需时间最少。综上所述,通过自动机器学习获取的机器学习模型对GEBV预测的准确性高于表型;GBM模型总体上表现出最高的预测准确性与较短训练时间;XGB能够利用最短的时间训练准确性较高的预测模型;RF模型的训练时间远超其他3种模型,且准确性不足,不适用猪生长性状表型与GEBV预测。
基金the Key Program of the National Natural Science Foundation of China(Grant No.61531003)the National Natural Science Foundation of China(Grant No.62001041)+1 种基金China Postdoctoral Science Foundation(Grant No.2020TQ0016)the Fund of State Key Laboratory of Information Photonics and Optical Communications.
文摘In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel,but also reduce the noise introduced by phase interference.However,arbitrary continuous modulation can not be carried out in the past polarization coding,resulting in that the signal state can not obtain arbitrary continuous value in Poincare space,and the security analysis of CV-QKD using polarized coherent-states in free space is not complete.Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller.In particular,in terms of the main influence factors in the free-space channel,we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate.In addition,the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather.Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather.The protocol fails when visibility is less than 1 km.At the same time,the wavelength can affect the performance of the proposed scheme.Specifically,under foggy weather,the longer the wavelength,the smaller the attenuation coefficient,and the better the transmission performance.Our proposed scheme can expand the modulation range of signal state,and supplement the security research of the scheme in the free-space channel,thus can provide theoretical support for subsequent experiments.
基金Supported by Non-funded Science and Technology Research Plan of Zhanjiang City(2023B01023)School-level Education and Teaching Reform Project of Lingnan Normal University(LNJW[2022]154).
文摘[Objectives]To analyze the gene structure of the protein that predicts 6-hydroxymellein synthase of Aspergillus terreus and predict the characteristics and functions of the protein structure encoded by the gene.[Methods]Various information analysis tools in NCBI,CBS and ExPASy websites were adopted.[Results]The QODIPO gene had a full length of 2954 bp,with 952 amino acids in the coding area,and QODIPO had the highest homology with the hypothetical protein ATETN484_0003008800.The molecular weight of QOD1PO protein was 105040.56,the theoretical isoelectric point(pl)was 5.69 and the grand average of hydropathieity was-0.242.It was speculated that QODIPO was an unstable and non-secretory hydrophilic protein located in cytoplasm without transmembrane domain or signal peptide.It could be predicted that the secondary structure of QODIPO encoding protein consisted mainly of random coil,α-helix and a PKS-DH anhydrase domain.[Conclusions]The results will lay a theoretical foundation for cloning and expression of 6-hydroxymellein synthase and further understanding of its activity and function.
基金supported by the National Natural Science Foundation of China (52072173)Jiangsu Province Outstanding Youth Fund (BK20200016)+1 种基金Jiangsu Specially-Appointed Professors ProgramLeading Edge Technology of Jiangsu Province (BK20202008)
文摘Simultaneously improving the energy density and power density of electrochemical energy storage systems is the ultimate goal of electrochemical energy storage technology.An effective strategy to achieve this goal is to take advantage of the high capacity and rapid kinetics of electrochemical proton storage to break through the power limit of batteries and the energy limit of capacitors.This article aims to review the research progress on the physicochemical properties,electrochemical performance,and reaction mechanisms of electrode materials for electrochemical proton storage.According to the different charge storage mechanisms,the surface redox,intercalation,and conversion materials are classified and introduced in detail,where the influence of crystal water and other nanostructures on the migration kinetics of protons is clarified.Several reported advanced full cell devices are summarized to promote the commercialization of electrochemical proton storage.Finally,this review provides a framework for research directions of charge storage mechanism,basic principles of material structure design,construction strategies of full cell device,and goals of practical application for electrochemical proton storage.
基金Jiangsu Province Research Foundation(Grant Nos.BK20191202,RK106STP18003,and SZDG2018007)the Jiangsu Province Research Foundation(Grant Nos.BK20191202,RK106STP18003,and SZDG2018007)+1 种基金the Research Innovation Program for College Graduates of Jiangsu Province(Grant Nos.KYCX200806,KYCX190960,and SJCX190268)NJUPTSF(Grant Nos.NY217116,NY220078,and NY218107)。
文摘In the post-Moore era,neuromorphic computing has been mainly focused on breaking the von Neumann bottlenecks.Memristors have been proposed as a key part of neuromorphic computing architectures,and can be used to emulate the synaptic plasticities of the human brain.Ferroelectric memristors represent a breakthrough for memristive devices on account of their reliable nonvolatile storage,low write/read latency and tunable conductive states.However,among the reported ferroelectric memristors,the mechanisms of resistive switching are still under debate.In addition,there needs to be more research on emulation of the brain synapses using ferroelectric memristors.Herein,Cu/PbZr_(0.52)Ti_(0.48)O_(3)(PZT)/Pt ferroelectric memristors have been fabricated.The devices are able to realize the transformation from threshold switching behavior to resistive switching behavior.The synaptic plasticities,including excitatory post-synaptic current,paired-pulse facilitation,paired-pulse depression and spike time-dependent plasticity,have been mimicked by the PZT devices.Furthermore,the mechanisms of PZT devices have been investigated by first-principles calculations based on the interface barrier and conductive filament models.This work may contribute to the application of ferroelectric memristors in neuromorphic computing systems.
基金This work was partly supported by National Key R&D Program of China,Grant No.2017YFB0309800the grants from the Natural Science Foundation of China(No.61472339,No.61303040,No.61572421,No.61272124)+1 种基金Shanghai Alliance Program(LM201552)Shanghai University of Engineering and Technology School-Enterprise cooperation projects(15)(DZ-025).
文摘Answering reachability queries is one of the fundamental graph operations.Existing approaches either accelerate index construction by constructing an index that covers only partial reachability relationship,which may result in performing cost traversing operation when answering a query;or accelerate query answering by constructing an index covering the complete reachability relationship,which may be inefficient due to comparing the complete node labels.We propose a novel labeling scheme,which covers the complete reachability relationship,to accelerate reachability queries processing.The idea is to decompose the given directed acyclic graph(DAG)G into two subgraphs,G1 and G2.For G1,we propose to use topological labels consisting of two integers to answer all reachability queries.For G2,we construct 2-hop labels as existing methods do to answer queries that cannot be answered by topological labels.The benefits of our method lie in two aspects.On one hand,our method does not need to perform the cost traversing operation when answering queries.On the other hand,our method can quickly answer most queries in constant time without comparing the whole node labels.We confirm the efficiency of our approaches by extensive experimental studies using 20 real datasets.
基金China Postdoctoral Science Foundation(2020TQ0016)National Natural Science Foundation of China(61531003,62201012)。
文摘High-precision time interval measurement is a fundamental technique in many advanced applications,including time and distance metrology,particle physics,and ultra-precision machining.However,many of these applications are confined by the imprecise time interval measurement of electrical signals,restricting the performance of the ultimate system to a few picoseconds,which limits ultrahigh precision applications.Here,we demonstrate an optical means for the time interval measurement of electrical signals that can successfully achieve femtosecond(fs)level precision.The setup is established using the optical frequency comb(OFC)based linear optical sampling(LOS)technique to realize timescale-stretched measurement.We achieve a measurement precision of 82 fs for a single LOS scan measurement and 3.05 fs for the 100-times average with post-processing,which is three orders of magnitude higher than the results of older electrical methods.The high-precision time interval measurement of electrical signals can substantially improve precision measurement technologies.
基金supported by the National Natural Science Foundation of China(NSFC)(No.11674111)Fujian Province Science Funds for Distinguished Young Scholar(No.2018J06017)+1 种基金Fundamental Research Funds for the Central Universities(No.ZQN-PY209)Science and Engineering Research Board(SERB)(No.India-EMR/2015/001613)。
文摘Encoding information using the topological charge of vortex beams has been proposed for optical communications. The conservation of the topological charge on propagation and the detection of the topological charge by a receiver are significant in these applications and have been well established in free-space. However, when vortex beams enter a diffuser,the wavefront is distorted, leading to a challenge in the conservation and detection of the topological charge. Here, we present a technique to measure the value of the topological charge of a vortex beam obscured in the randomly scattered light. The results of the numerical simulations and experiments are presented and are in good agreement. In particular, only a single-shot measurement is required to detect the topological charge of vortex beams, indicating that the method is applicable to a dynamic diffuser.
基金supported by the Key Program of National Natural Science Foundation of China(Grant No.61531003)the National Natural Science Foundation of China(Grant No.62001041)the Fund of State Key Laboratory of Information Photonics and Optical Communications。
文摘In the practical continuous-variable quantum key distribution(CV-QKD)system,the postprocessing process,particularly the error correction part,significantly impacts the system performance.Multi-edge type low-density parity-check(MET-LDPC)codes are suitable for CV-QKD systems because of their Shannon-limit-approaching performance at a low signal-to-noise ratio(SNR).However,the process of designing a low-rate MET-LDPC code with good performance is extremely complicated.Thus,we introduce Raptor-like LDPC(RL-LDPC)codes into the CV-QKD system,exhibiting both the rate compatible property of the Raptor code and capacity-approaching performance of MET-LDPC codes.Moreover,this technique can significantly reduce the cost of constructing a new matrix.We design the RL-LDPC matrix with a code rate of 0.02 and easily and effectively adjust this rate from 0.016 to 0.034.Simulation results show that we can achieve more than 98%reconciliation efficiency in a range of code rate variation using only one RL-LDPC code that can support high-speed decoding with an SNR less than-16.45 d B.This code allows the system to maintain a high key extraction rate under various SNRs,paving the way for practical applications of CV-QKD systems with different transmission distances.
基金supported by grants from the following institutions:the High-level Talent Start-up Funding of Southern Medical Universitythe National Natural Science Foundation of China(grant numbers:31700061,81971420 and 81991511)+2 种基金the Guangdong Special Support Program for Youth Science and Technology Innovation Talents(grant number:2019TQ05Y585)the National Natural Science Foundation of Guangdong(grant number:2019A1515011435)the Science and Technology Program of Guangzhou(grant number:201904010073).
文摘The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role in maintaining feto-maternal tolerance,little is known about the role of MDSCs in pregnancies with intrauterine growth retardation(IUGR).Here,we reported that the activation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)during pregnancy was closely associated with fetal growth.In humans,class E scavenger receptor 1(SR-E1),a distinct marker for human PMN-MDSCs,was used to investigate PMN-MDSC function during pregnancy.Continuous activation of SR-E1+PMN-MDSCs was observed in all stages of pregnancy,accompanied by high cellular levels of ROS and arginase-1 activity,mediated through STAT6 signaling.However,SR-E1+PMN-MDSCs in pregnancies with IUGR showed significantly lower suppressive activity,lower arginase-1 activity and ROS levels,and decreased STAT6 phosphorylation level,which were accompanied by an increase in inflammatory factors,compared with those in normal pregnancies.Moreover,the population of SR-E1+PMN-MDSCs was negatively correlated with the adverse outcomes of newborns from pregnancies with IUGR.In mice,decreases in cell population,suppressive activity,target expression levels,and STAT6 phosphorylation levels were also observed in the pregnancies with IUGR compared with the normal pregnancies,which were rescued by the adoptive transfer of PMN-MDSCs from pregnant mice.Interestingly,the growth-promoting factors(GPFs)secreted by placental PMN-MDSCs in both humans and mice play a vital role in fetal development.These findings collectively support that PMN-MDSCs have another new role in pregnancy,which can improve adverse neonatal outcomes.
基金supported by the National Natural Science Foundation of China(81773674,21473041,81573383)Natural Science Foundation of Hubei Province(2017CFB711,2017CFA024,2016ACA126)+3 种基金the Fundamental Research Funds for the Central Universities,Tibet Autonomous Region Science and Technology Plan Project Key Project(XZ201901-GB-11)the Applied Basic Research Program of Wuhan Municipal Bureau of Science and Technology(2019020701011429)Project First-Class Disciplines Development Supported by Chengdu University of Traditional Chinese Medicine(CZYJC1903)Health Commission of Hubei Province Scientific Research Project(WJ2019M178,WJ2019M177)。
文摘Osteosarcoma is the most common primary malignant tumor of bone,particularly among children and adolescents.Advances in imaging,surgical techniques,and implants have dramatically reduced the need for amputation in the past three decades.Recently,in vivo fluorescence imaging in the second near-infrared window(NIR-II,1,000–1,700 nm)shows impressive advantages of deeper tissue penetration and higher spatial resolution,which makes it a promising tool for the early diagnosis and post-operative observation of Osteosarcoma.To the best of our knowledge,this paper is the first time to develop a novel NIR-II fluorescence probe conjugated with an osteosarcoma targeted oligopeptide for molecular tumor imaging in a xenograft orthotopic osteosarcoma mouse model.
基金supported by the National Natural Science Foundation of China(Grant No.62005086)the External Cooperation Program of Chinese Academy of Sciences(Grant No.121835KYSB20180062)the Regional Key Project of Chinese Academy of Sciences(Grant No.KFJ-STSQYZX-110)。
文摘The orbital angular momentum(OAM)of vortex beams offers a new degree for information encoding,which has been applied to optical communications.OAM measurement is essential for these applications,and has been realized in free space by several methods.However,these methods are inapplicable to estimate the OAM of vortex beams directly from the speckle patterns in the exit end of a multimode fiber(MMF).To tackle this issue,we design a convolutional neural network(CNN)to realize 100%accuracy recognition of two orthogonally polarized OAM modes from speckle patterns.Moreover,we demonstrate that even when the speckle patterns are cropped to only 1/64 of the original patterns,the recognition accuracy of the designed neural network is still higher than 98%.We also study the recognition accuracy of cropped speckles in different areas of speckle patterns to verify the feasibility of OAM recognition after cropping.The results demonstrate that recognizing the OAMs of two orthogonally polarized vortex beams from only a portion of speckle patterns in the exit end of an MMF is feasible,offering the potential to construct a 1×N data transmission scheme.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.61178015 and 11304104the Open Research Fund of the National Laboratory on High Power Laser and Physics under Grant No.SG-001102
文摘The intensity distributions of a high-power broadband laser beam passing through a nonlinear optical medium with defects and then propagating in free space are investigated based on the general nonlinear Schr¨odinger equation and the split-step Fourier numerical method. The influences of the bandwidth of the laser beam, the thickness of the medium,and the defects on the light intensity distribution are revealed. We find that the nonlinear optical effect can be suppressed and that the uniformity of the beam can be improved for a high-power broadband laser beam with appropriate wide bandwidth. It is also found that, under the same incident light intensity, a thicker medium will lead to a stronger self-focusing intensity, and that the influence of defects in the optical elements on the intensity is stronger for a narrowband beam than for a broadband beam.
基金This work was supported by the National Natural Science Foundation of China(No.12074207).
文摘The spatial rogue waves(RWs)generated by a wide Gaussian beam in a saturated nonlinear system are experimentally observed.Our observations show that RWs are most likely to occur when Gaussian light evolves to the critical state of filament splitting,and then the probability of RWs decreases with voltage fluctuations.The occurrence probability of RWs after splitting is related to the nonlinear breathing phenomenon of optical filament,and the statistics of RWs satisfy the long-tailed L-shaped distribution.The experiment proves that the presence of high-frequency components and the aggregation of low-frequency components can serve as a prerequisite for the occurrence of extreme events(EEs).
