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Cache Pollution Prevention Mechanism Based on Deep Reinforcement Learning in NDN

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Journal of Communications and Information Networks 2021年第1期6卷 91-100页

作者： Jie zhou Jiangtao Luo junxia Wang Lianglang Deng School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Electronic Information and Networking Research Institute Chongqing University of Posts and TelecommunicationsChongqing 400065China

As a representative architecture of contentcentric paradigms for the future Internet,named data networking(NDN)enables consumers to retrieve content duplicates from either the original server or intermediate routers.Each node of NDN is equipped with cache that buffers but not validates the data,making it vulnerable to various attacks.Cache pollution,one of the specific attacks in NDN,fraudulently alters the cached contents by excessively requesting worthless information,squeezing the space of real popular contents and thus degrading the experience of normal users.In order to address the issue,this paper proposes a defense scheme based on deep reinforcement learning(DRL)against cache pollution attack,in which whether a data packet is to be cached is decided by a trained intelligent agent,that is adaptive to dynamic network states and following long term rewards,the accumulative data-requesting delays.Finally,the DRL-based scheme is evaluated and compared to two other existing schemes.Experimental results show that the proposed defense mechanism outperforms the others significantly,and is proved to be effective against cache pollution attacks.

关键词： named data networking cache pollution attack deep reinforcement learning

Long-term declining in carbon monoxide(CO)at a rural site of Beijing during 2006-2018 implies the improved combustion efficiency and effective emission control

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Journal of Environmental Sciences 2022年第5期34卷 432-442页

作者： Yingruo Li Zhiqiang Ma Tingting Han Weijun Quan junxia Wang Huaigang zhou Di He Fan Dong Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China Key Laboratory of Atmospheric Chemistry China Meteorological AdministrationBeijing 100081China Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei China Meteorological AdministrationBeijing 100089China College of Environmental Science and Engineering Peking UniversityBeijing 100871China

Carbon monoxide(CO)is primarily the result of incomplete combustion,which has impor-tant impacts on the atmospheric chemical cycle and climate.Improved quantitative char-acterization of long-term CO trends is important for both atmospheric modeling and the design and implementation of policies to efficiently control multiple pollutants.Due to the limitations of high time-resolution and high-quality long-term observational data,studies on long-term trends in the CO concentration in China are quite limited.In this study,the observational data of the concentration of CO in a rural site of Beijing during 2006-2018 was used to analyze the long-term trend in CO concentration in Beijing.The Theil-Sen method and the generalized additive model(GAM)-based method,were used to conduct the trend estimation analysis.We found that the concentration of CO at the Shangdianzi site showed a significant downward trend during 2006-2018,with a decline rate of 22.8±5.1 ppbV per year.The declining trend in CO also showed phasic characteristics,with a fast decreasing rate during the period of 2006-2008,stable variations during the period of 2009-2013 and a continuous downward trend after 2013.The declining trend in the CO concentration in the south to west(S-W)sectors where the polluted air masses come from is more rapid than that in the sectors where the clean air masses come from.The declining trend in the CO concentration implies the improved combustion efficiency and the successful air pollution control policies in Beijing and the surrounding area.

关键词： Carbon monoxide Long-term trend Theil-Sen method Generalized additive model (GAM)-based method Stratified analysis

Clinical characteristics of radiation-induced optic neuropathy:A single-center retrospective study

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Advances in Ophthalmology Practice and Research 2023年第3期3卷 141-146页

作者： Yongping Wang junxia Fu Huanfen zhou Hongen Li Quangang Xu Shihui Wei Department of Ophthalmology Chinese PLA General HospitalBeijingChina

Purpose:To observe the clinical and imaging characteristics of radiation-induced optic neuropathy(RION).Methods:We retrospectively reviewed the clinical data of 43 patients(69 eyes)who were diagnosed with RION at the Chinese PLA General Hospital from 2010 to 2021.Results:The latency from radiotherapy to onset of visual loss ranged from 1 to 132(36.33±30.48)months.Optic disc pallor and optic disc edema were found in 27.0%(10/37)and 8.1%(3/37)of the eyes,respectively,within 2 months.After treatment,the best corrected visual acuity(BCVA)was restored in 24.6%(17/69)of the eyes and the final BCVA improved in 13.0%(9/69)of the eyes.An 82.5%(33/40)of the eyes with magnetic resonance imaging(MRI)showed enhancement of the affected optic nerve,mostly(69.7%)in the intracranial segment,and 36.4%(12/33)of the eyes with expansion and T2-high signals also showed enhancement of the affected optic nerve.The superior retinal nerve fiber layer(RNFL)and the outer circle superior quadrant(OS)of the inner limiting membrane to retinal pigment epithelium(ILM-RPE)layer thinned significantly during the first month.The center of the ILM-RPE layer thickened significantly during the first two months and the inner circle temporal quadrant(IT)of the ILM-RPE layer thickened significantly from the third to sixth month.The RNFL thinned significantly after 6 months except for the temporal quadrant,and the average inner circle superior quadrant(IS)and outer circle of the ILM-RPE layer thinned significantly after 6 months.There was no significant difference between hyperbaric oxygen therapy(HBOT)and high-dose intravenous methylprednisolone(IVMP)therapy in improving BCVA recovery or final BCVA(P>0.05).Conclusions:The structural damage of the RNFL and ILM-RPE layer occurred during the first month,the RNFL showed progressive thinning during the follow-up period,while the ILM-RPE layer showed thinning during the first month,thickening from the third to sixth month,and thinning after 6 months.There was a discrete region of enhancement of the optic nerve,

关键词： Radiation-induced optic neuropathy(RION) Magnetic resonance imaging(MRI) Optical coherence tomography(OCT) Hyperbaric oxygen therapy(HBOT) High-dose intravenous methyl prednisolone (IVMP)

Fish scale-derived scaffolds with MSCs loading for photothermal therapy of bone defect

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Nano Research 2023年第5期16卷 7383-7392页

作者： Siyu Shen Rui Liu Chuanhui Song Tao Shen Yiwen zhou junxia Guo Bin Kong Qing Jiang State Key Laboratory of Pharmaceutical Biotechnology Division of Sports Medicine and Adult Reconstructive SurgeryDepartment of Orthopedic SurgeryNanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008China Branch of National Clinical Research Center for Orthopedics Sports Medicine and RehabilitationNanjing 210008China The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing 210008China Department of Orthodontics Nanjing Stomatological HospitalMedical School of Nanjing UniversityNanjing 210008China Department of Sports Medicine and Adult Reconstructive Surgery Nanjing Drum Tower HospitalClinical College of Nanjing Medical UniversityNanjing 210008China Department of Biomedical Engineering School of MedicineShenzhen UniversityShenzhen 518060China

Tissue engineering scaffolds have presented effective value in bone repair.However,the integration of the diverse components,complex structures,multifunction to impart the scaffolds with improved applicability is still a challenge.Here,we propose a novel fish-derived scaffold combined with photothermal therapy and mesenchymal stem cells(MSCs)to promote bone regeneration.The fish-derived scaffold is composed of the decellularized fish scale and gelatin methacrylate synthesized from fish gelatin(fGelMA),which can promote the proliferation and osteogenesis of MSCs with no obvious immunological rejection.Furthermore,the black phosphorus(BP)nanosheets are incorporated into the fGelMA hydrogel network,which can endow the hydrogel with the capacity of photothermal conversion stimulated by near-infrared(NIR)light.The fish-derived scaffold can promote the osteogenesis process of MSCs with higher expression of osteogenic markers and higher mineralization assisted by the NIR light in vitro.The regeneration of mice calvarial defect has also been accelerated by the scaffold with photothermal therapy and MSCs.These results suggest that the fish-derived scaffold,photothermal therapy,MSCs-based regenerative therapy is a promising clinical strategy in bone regeneration.

关键词： fish scale GelMA photothermal therapy mesenchymal stem cell bone regeneration

Transcriptome Analysis of Schwann Cells at Various Stages of Myelination Implicates Chromatin Regulator Sin3A in Control of Myelination Identity

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Neuroscience Bulletin 2022年第7期38卷 720-740页

作者： Bin Zhang Wenfeng Su junxia Hu Jinghui Xu Parizat Askar Shuangxi Bao Songlin zhou Gang Chen Yun Gu Jiangsu Key Laboratory of Neuroregeneration Co-innovation Center of NeuroregenerationJiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury RepairNMPAKey Laboratory for ResearchEvaluation of Tissue Engineering Technology ProductsNantong UniversityNantong 226001China

Enhancing remyelination after injury is of utmost importance for optimizing the recovery of nerve function.While the formation of myelin by Schwann cells(SCs)is critical for the function of the peripheral nervous system,the temporal dynamics and regulatory mechanisms that control the progress of the s lineage through myelination require further elucidation.Here,using in vitro co-culture models,gene expression profiling of laser capture-microdissected SCs at various stages of myelination,and multilevel bioinformatic analysis,we demonstrated that SCs exhibit three distinct transcriptional characteristics duringmyelination:the immature,promyelinating,and myelinating states.We showed that suppressor interacting 3a(Sin3A)and 16 other transcription factors and chromatin regulators play important roles in the progress of myelination.Sin3A knockdown in the sciatic nerve or specifically in SCs reduced or delayed the myelination of regenerating axons in a rat crushed sciatic nerve model,while overexpression of Sin3A greatly promoted the remyelination of axons.Further,in vitro experiments revealed that Sin3A silencing inhibited SC migration and differentiation at the promyelination stage and promoted SC proliferation at the immature stage.In addition,SC differentiation and maturation may be regulated by the Sin3A/histone deacetylase2(HDAC2)complex functionally cooperating with Sox10,as demonstrated by rescue assays.Together,these results complement the recent genome and proteome analyses of SCs during peripheral nerve myelin formation.The results also reveal a key role of Sin3A-dependent chromatin organization in promoting myelinogenic programs and SC differentiation to control peripheral myelination and repair.These findings may inform new treatments for enhancing remyelination and nerveregeneration.

关键词： (Re)myelination Schwann cells Sin3A Transcriptome Peripheral nerve injury

Genome-wide Expansion and Expression Divergence of the Basic Leucine Zipper Transcription Factors in Higher Plants with an Emphasis on Sorghum

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Journal of Integrative Plant Biology 2011年第3期53卷 212-231页

作者： Jizhou Wang Junxia Zhou Baolan Zhang Jeevanandam Vanitha Srinivasan Ramachandran Shu-Ye Jiang Institute of Botany and Temasek Life Sciences Laboratory Joint Research & Development Laboratory Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Temasek Life Sciences Laboratory 1 Research Link the National University of Singapore Singapore 117604 Singapore

Plant bZIP transcription factors play crucial roles in multiple biological processes. However, little is known about the sorghum bZIP gene family although the sorghum genome has been completely sequenced. In this study, we have carried out a genome-wide identification and characterization of this gene family in sorghum. Our data show that the genome encodes at least 92 bZIP transcription factors. These bZIP genes have been expanded mainly by segmental duplication. Such an expansion mechanism has also been observed in rice, arabidopsis and many other plant organisms, suggesting a common expansion mode of this gene family in plants. Further investigation shows that most of the bZIP members have been present in the most recent common ancestor of sorghum and rice and the major expansion would occur before the sorghum-rice split era. Although these bZlP genes have been duplicated with a long history, they exhibited limited functional divergence as shown by nonsynonymous substitutions （Ka）lsynonymous substitutions （Ks） analyses. Their retention was mainly due to the high percentages of expression divergence. Our data also showed that this gene family might play a role in multiple developmental stages and tissues and might be regarded as important regulators of various abiotic stresses and sugar signaling.

关键词： LEUCINE zippers TRANSCRIPTION factors SORGHUM GENETICS PLANT genomes PLANT gene expression DIVERGENCE (Biology) CARRIER proteins

Carbon Isotope Gradient of the Ediacaran Cap Carbonate in the Shennongjia Area and Its Implications for Ocean Stratification and Palaeogeography

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Journal of Earth Science 2017年第2期28卷 187-195页

作者： Guangzhe Wang Jiasheng Wang zhou Wang Can Chen junxia Yang State Key laboratory of Biogeology and Environment Geology School of Earth Sciences China University of Geosciences Institute of Karst Geology CAGS Key Laboratory of Karst Ecosystem and Treatment of Rocky Desertification MLR

The geochemistry and paleogeography of the Doushantuo succession in the Shennongjia area have been insufficiently studied. Here, we report on the carbon and oxygen isotope compositions of Ediacaran Doushantuo cap carbonates from four sections（Longxi, Muyu, Yazikou and Songluo） in the Shennongjia area. A large C-isotopic gradient（~5‰） between the Longxi and Songluo sections, here identified for the first time, is inferred to have been dynamically maintained by photosynthesis in surface waters and anaerobic oxidation of dissolved organic carbon（DOC） in deep waters. Spatial variation in C-isotope chemostratigraphy among the four sections was related to Marinoan post-glacial sea-level elevation changes. At Longxi, a positive δ^（13）C_（carb） shift below the horizon containing tepee-like structure resulted from intense photosynthesis during early regression. A negative δ^（13）C_（carb） shift within the tepee-horizon was triggered by sulfate reduction and freshwater mixing with ^（13）C-depleted dissolved inorganic carbon（DIC） during late regression. A positive δ^（13）C_（carb） excursion in the uppermost part of the cap carbonate was related to enhance primary productivity and organic matter burial during early transgression. At Muyu, the carbon isotopic variation tendency, which is similar to that at Longxi, may have been mildly influenced by the surface water environment. At Songluo, the positive δ^（13）C_（carb） excursion, up to-4‰ in the lower part of the cap carbonate, was probably associated with methanogenesis in deep waters during late transgression to early regression and subsequently disappeared due to decomposition of methane hydrate during late regression. At Yazikou, the consistently stable δ^（13）C_（carb） values around-4‰ indicate that the cap carbonate may have deposited at intermediate water depths. As evidenced by diagnostic sedimentary characteristics of the study sections, the palaeogeographic framework of the Shennongjia area exhibited deepening from SE to NW during the Early Ediacaran Period in the aftermath

关键词： Ediacaran Doushantuo cap carbonate carbon isotope stratification palaeogeography,Shennongjia.

Novel Ag-bridged dual Z-scheme g-C_(3)N_(4)/BiOI/AgI plasmonic heterojunction: Exceptional photocatalytic activity towards tetracycline and the mechanism insight

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Journal of Environmental Sciences 2023年第9期131卷 123-140页

作者： Wenxia Wang Zhen Li Kailin Wu Guodong Dai Qingping Chen Lihua zhou junxia Zheng Liang Ma Guiying Li Wanjun Wang Taicheng An School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key lab of Clean Transport Energy and Chemistry Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Rational design and synthesis of highly efficient and robust photocatalysts with positive exciton splitting and interfacial charge transfer for environmental applications is critical.Herein,aiming at overcoming the common shortcomings of traditional photocatalysts such as weak photoresponsivity,rapid combination of photo-generated carriers and unstable structure,a novel Ag-bridged dual Z-scheme g-C_(3)N_(4)/BiOI/AgI plasmonic heterojunction was successfully synthesized using a facile method.Results showed that Ag-AgI nanoparticles and three-dimensional(3D)BiOI microspheres were decorated highly uniformly on the 3D porous g-C_(3)N_(4) nanosheet,resulting in a higher specific surface area and abundant active sites.The optimized 3D porous dual Z-scheme g-C_(3)N_(4)/BiOI/Ag-AgI manifested exceptional photocatalytic degradation efficiency of tetracycline(TC)in water with approximately 91.8%degradation efficiency within 165 min,outperforming majority of the reported g-C_(3)N_(4)-based photocatalysts.Moreover,g-C_(3)N_(4)/BiOI/Ag-AgI exhibited good stability in terms of activity and structure.In-depth radical scavenging and electron paramagnetic resonance(EPR)analyses confirmed the relative contributions of various scavengers.Mechanism analysis indicated that the improved photocatalytic performance and stability were ascribed to the highly ordered 3D porous framework,fast electron transfer of dual Z-scheme heterojunction,desirable photocatalytic performance of BiOI/AgI and synergistic effect of Ag plasmas.Therefore,the 3D porous Z-scheme g-C_(3)N_(4)/BiOI/Ag-AgI heterojunction had a good prospect for applications in water remediation.The current work provides new insight and useful guidance for designing novel structural photocatalysts for environment-related applications.

关键词： Three-dimensional Porous heterostructure Graphitic carbon nitride(g-C_(3)N_(4)) Dual Z-scheme heterojunction Tetracycline(TC)degradation Mechanism insight

Analysis of Boundary Layer Structure,Turbulence,and Flux Variations before and after the Passage of a Sea Breeze Front Using Meteorological Tower Data

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Journal of Meteorological Research 2023年第6期37卷 855-877页

作者： Ju LI junxia DOU Donald H. LENSCHOW Mingyu zhou Lihong MENG Xiaobin QIU Yubing PAN Jingjiang ZHANG Institute of Urban Meteorology(Key Laboratory of Urban Meteorology) China Meteorological AdministrationBeijing100089China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing100081China Beijing Research Center for Urban Meteorological Engineering and Technology Beijing100081China National Center for Atmospheric Research BoulderCO80307USA National Marine Environmental Prediction Center Beijing100081China Tianjin Key Laboratory for Oceanic Meteorology Tianjin300074China Tianjin Institute of Meteorological Science Tianjin300074China

A detailed analysis of a sea breeze front(SBF)that penetrated inland in the Beijing–Tianjin–Hebei urban agglomeration of China was conducted.We focused on the boundary layer structure,turbulence intensity,and fluxes before and after the SBF passed through two meteorological towers in the urban areas of Tianjin and Beijing,respectively.Significant changes in temperature,humidity,winds,CO_(2),and aerosol concentrations were observed as the SBF passed.Differences in these changes at the two towers mainly resulted from their distances from the ocean,boundary layer conditions,and background turbulences.As the SBF approached,a strong updraft appeared in the boundary layer,carrying near-surface aerosols aloft and forming the SBF head.This was followed by a broad downdraft,which destroyed the near-surface inversion layer and temporarily increased the surface air temperature at night.The feeder flow after the thermodynamic front was characterized by low-level jets horizontally,and downdrafts and occasional updrafts vertically.Turbulence increased significantly during the SBF’s passage,causing an increase in the standard deviation of wind components in speed.The increase in turbulence was more pronounced in a stable boundary layer compared to that in a convective boundary layer.The passage of the SBF generated more mechanical turbulences,as indicated by increased friction velocity and turbulent kinetic energy(TKE).The shear term in the TKE budget equation increased more significantly than the buoyancy term.The atmosphere shifted to a forced convective state after the SBF’s passage,with near isotropic turbulences and uniform mixing and diffusion of aerosols.Sensible heat fluxes(latent heat and CO_(2)fluxes)showed positive(negative)peaks after the SBF’s passage,primarily caused by horizontal and vertical transport of heat(water vapor and CO_(2))during its passage.This study enhances understanding of boundary layer changes,turbulences,and fluxes during the passage of SBFs over urban areas.

关键词： sea breeze front boundary layer structure turbulence flux meteorological tower