Editing of eIF(iso)4E.c confers resistance against Turnip mosaic virus in Brassica rapa

Turnip mosaic virus(TuMV)constitutes one of the primary diseases affecting Brassica rapa,severely impacting its production and resulting in crop failures in various regions worldwide.Recent research has demonstrated the significance of plant translation initiation factors,specifically the eIF4E and eIF4G family genes,as essential recessive disease resistance genes.In our study,we conducted evolutionary and gene expression studies,leading us to identify e IF(iso)4E.c as a potential TuMV-resistant gene.Leveraging CRISPR/Cas9 technology,we obtained mutant B.rapa plants with edited eIF(iso)4E.c gene.We confirmed eIF(iso)4E.c confers resistance against TuMV through phenotypic observations and virus content evaluations.Furthermore,we employed ribosome profiling assays on eif(iso)4e.c mutant seedlings to unravel the translation landscape in response to TuMV.Interestingly,we observed a moderate correlation between the fold changes in gene expression at the transcriptional and translational levels(R^(2)=0.729).Comparative analysis of ribosome profiling and RNA-seq data revealed that plant-pathogen interaction,and MAPK signaling pathway-plant pathways were involved in eIF(iso)4E.c-mediated TuMV resistance.Further analysis revealed that sequence features,coding sequence length,and normalized minimal free energy,influenced the translation efficiency of genes.Our study highlights that the loss of e IF(iso)4E.c can result in a highly intricate translation mechanism,acting synergistically with transcription to confer resistance against TuMV.

Development of a Novel Extrusion Process for Preparing Rice Straw/LLDPE Composites

Straw utilization is a key issue related to agricultural production and air pollution control.In this study,a novel extrusion process was proposed to improve the physical and mechanical properties of the straw-reinforced linear low-density polyethylene(LLDPE)composite.Instead of crushing the straw and mixing it with plastic matrix,the new method mixes straw with plastic matrix in its original form.The intact long rice straws were parallelly spread on the LLDPE film and then rolled up together into a prefabricated roll.The rolls experienced three extrusion processes as follows:(1)twin-screw melting,cooling and crushing,single-screw extruding;(2)twin-screw melting and single-screw extruding;(3)directly single-screw extruding.The testing results showed that the straw/LLDPE composite(with a ratio of 6:4)prepared by Method(2)exhibited optimized properties.Characterization by scanning electron microscopy indicated that the damage to rice straw fibers was relatively minor,the orientation of long fibers was good,and the binding of fibers with the LLDPE matrix was excellent in this case.The results of dynamic mechanical testing(DMA),differential scanning calorimetry(DSC)and thermogravimetric(TG)analysis demonstrated that composites prepared by the new process exhibited significantly improved thermal stability and energy storage modulus,compared with those prepared by conventional processes(e.g.,extruded straw particles/LLDPE composite).The new proposed method yielded significantly enhanced mechanical properties while reducing dust pollution.

苯甲酸、对甲苯胺、乙酰苯胺三组分分离实验教学设计

分离提纯是有机合成中关键的实验步骤,反应后处理这部分的工作内容要占到90%的工作量。为提高学生从混合物中分离目标化合物的实验技能,进一步锻炼学生综合运用萃取、蒸馏、重结晶等纯化实验操作,中南大学化学化工学院有机化学教学组在有机化学实验教学中安排了"三组分混合物分离"实验,面向的学生为医学临床五年制和八年制、化学化工学院的制药工程及应用化学专业。本文详细探讨了该实验的酸、碱分离两种教学方案,对先加酸分离得到的三个组分进行了1H NMR测试。从两个方案的实验教学效果来看,先加酸或先加碱对实验结果没有影响。

Effect of three tree species on UV weathering of wood flour-HDPE composites

Eucalyptus urophylla, Acacia mangium, and Pinus caribaea are the primary species for the wood industry in Vietnam. Wood residues of these species were used to reinforce high-density polyethylene(HDPE) composites. The flexural or bending property, impact strength and surface color were evaluated after exposure to accelerated ultraviolet weathering up to 2000 h. The weathered surface was characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy. The results indicate that A. mangium/HDPE composites had the lowest color change and least fading,and remained stable after 1500 h exposure. FTIR spectroscopy showed that the oxidation of the composites increased in parallel with duration of exposure by assessing the concentration of carbonyl groups on the surfaces. SEM showed that all three species reinforced composites exhibited similar severe cracks after 1000 h;however, at the end of the weathering test, E. urophylla and P. caribaea composites were more severely cracked than A. mangium composites. A. mangium also had the highest flexural strength, impact strength and crystallinity duringweathering. A. mangium is the most preferable among the three species to reinforce HDPE.

Identification of long noncoding RNAs involved in resistance to downy mildew in Chinese cabbage

Brassica downy mildew,a severe disease caused by Hyaloperonospora brassicae,can cause enormous economic losses in Chinese cabbage(Brassica rapa L.ssp.pekinensis)production.Although some research has been reported recently concerning the underlying resistance to this disease,no studies have identified or characterized long noncoding RNAs involved in this defense response.In this study,using high-throughput RNA sequencing,we analyzed the disease-responding mRNAs and long noncoding RNAs in two resistant lines(T12–19 and 12–85)and one susceptible line(91–112).Clustering and Gene Ontology analysis of differentially expressed genes(DEGs)showed that more DEGs were involved in the defense response in the two resistant lines than in the susceptible line.Different expression patterns and proposed functions of differentially expressed long noncoding RNAs among T12–19,12–85,and 91–112 indicated that each has a distinct disease response mechanism.There were significantly more cis-and trans-functional long noncoding RNAs in the resistant lines than in the susceptible line,and the genes regulated by these RNAs mostly participated in the disease defense response.Furthermore,we identified a candidate resistance-related long noncoding RNA,MSTRG.19915,which is a long noncoding natural antisense transcript of a MAPK gene,BrMAPK15.Via an agroinfiltration-mediated transient overexpression system and virus-induced gene silencing technology,BrMAPK15 was indicated to have a greater ability to defend against pathogens.MSTRG.19915-silenced seedlings showed enhanced resistance to downy mildew,probably because of the upregulated expression of BrMAPK15.This research identified and characterized long noncoding RNAs involved in resistance to downy mildew,laying a foundation for future in-depth studies of disease resistance mechanisms in Chinese cabbage.

Degenerative alterations in noradrenergic neurons of the locus coeruleus in Alzheimer's disease

Mice carrying mutant amyloid precursor protein and presenilin-1 genes （APP/PS1 double trans- genic mice） have frequently been used in studies of Alzheimer＇s disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer＇s disease is known to correlate with the amount of amyloid-13 protein deposition and the number of dead neurons in the locus coeruleus. In the present study, we assigned APP/PS1 double transgenic mice to two groups according to age： young mice （5-6 months old） and aged mice （16-17 months old）. Age-matched wild-type mice were used as controls. Immunohistochemistry for tyrosine hydroxylase （a marker of catecholaminergic neurons in the locus coeruleus） revealed that APP/PS1 mice had 23% fewer cells in the locus coeruleus compared with aged wild-type mice. APP/PS1 mice also had increased numbers of cell bodies of neurons positive for tyrosine hydroxylase, but fewer tyrosine hydroxylase-positive fibers, which were also short, thick and broken. Quantitative analysis using unbiased stereology showed a significant age-related increase in the mean volume of tyrosine hy- droxylase-positive neurons in aged APP/PS1 mice compared with young APP/PS1 mice. Moreover, the mean volume of tyrosine hydroxylase-positive neurons was positively correlated with the total volume of the locus coeruleus. These findings indicate that noradrenergic neurons and fibers in the locus coeruleus are predisposed to degenerative alterations in APP/PS1 double transgenic mice.

Properties of paper mill sludge–wood fiber–HDPE composites after exposure to xenon-arc weathering

We used paper mill sludge（PMS） to substitute for part of the wood fibers（WF） used to reinforce high density polyethylene（HDPE）.The resulting composites were subjected to xenon-arc weathering.The composite filled with limited PMS（under 10 %） had mechanical properties and aging resistance similar to those without PMS.The composites containing more PMS faded and cracked more readily than those without PMS.Based on the carbonyl index,crystallinity,and wood index,PMS appeared to accelerate the degradation of composites during weathering.Adding PMS to WF–HDPE composites reduced the weathering resistance,and this reduction was not significant if the PMS content did not exceed 20 % of the wood fibers.Therefore,PMS could be used as a reinforcement in wood-plastic composites at levels less than20 % of the wood fiber content.

Genome-wide analysis of changes in miRNA and target gene expression reveals key roles in heterosis for chinese cabbage biomass

Heterosis is a complex phenomenon in which hybrids show better phenotypic characteristics than their parents do.Chinese cabbage(Brassica rapa L.spp.pekinensis)is a popular leafy crop species,hybrids of which are widely used in commercial production;however,the molecular basis of heterosis for biomass of Chinese cabbage is poorly understood.We characterized heterosis in a Chinese cabbage hybrid cultivar and its parental lines from the seedling stage to the heading stage;marked heterosis of leaf weight and biomass yield were observed.Small RNA sequencing revealed 63 and 50 differentially expressed microRNAs(DEMs)at the seedling and early-heading stages,respectively.The expression levels ofthe majority of miRNA clusters in the hybrid were lower than the mid-parent values(MPVs).Using degradome sequencing,we identi fied 1,819 miRNA target genes.Gene ontology(GO)analyses demonstrated that the target genes ofthe MPV-DEMs and low parental expression level dominance(ELD)miRNAs were signi ficantly enriched in leaf morphogenesis,leaf development,and leaf shaping.Transcriptome analysis revealed that the expression levels of photosynthesis and chlorophyll synthesis-related MPV-DEGs(differentially expressed genes)were signi ficantly different in the F_(1) hybrid compared to the parental lines,resulting in increased photosynthesis capacity and chlorophyll content in the former.Furthermore,expression of genes known to regulate leaf development was also observed at the seedling stage.Arabidopsis plants overexpressing BrGRF4.2 and bra-miR396 presented increased and decreased leaf sizes,respectively.These results provide new insight into the regulation of target genes and miRNA expression patterns in leaf size and heterosis for biomass of B.rapa.

Non-isothermal crystallization kinetics of wood-flour/polypropylene composites in the presence of b-nucleating agent

The influence of aryl amide compounds（TMB）as b-nucleating agents, on the non-isothermal crystallization of a wood-flour/polypropylene composite（WF/PP）prepared by compression molding was investigated by wide-angle X-ray diffraction and differential scanning calorimetry. TMB was proved to be an effective b-crystalline nucleating agent for WF/PP. The DSC data showed that the crystallization peak temperature（Tp） increased and the half-time（t1/2） decreased with the addition of TMB.Three theoretical models were used to analyze the nonisothermal crystallization process. The modified Avrami method and Mo method successfully explained the nonisothermal crystallization behavior of PP and its composites. Their activation energies for non-isothermal crystallization were determined basing on the Kissinger method.

Effect of an antioxidant on the life cycle of wood flour/polypropylene composites

This study assessed the life cycle of biocomposites with antioxidants by repeated processing.The effects of antioxidants on the life cycle of wood flour/polypropylene(PP)composites were determined by analyzing their mechanical and thermal properties.The composites were repeatedly processed for seven times with pelletizing and extruding.An antioxidant,pentaerythritoltetrakys 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate,was used.The mechanical strength of the biocomposites decreased after reprocessing.Fourier transformed infrared analysis showed that thermo-oxidative aging occurred during reprocessing.The thermal performance of the resulting composites decreased because of reprocessing.Wood flour/PP has a long lifetime and antioxidants can slow the thermo-oxidative and mechanical degradation during reprocessing.

Decorative Wood Fiber/High-Density Polyethylene Composite with Canvas or Polyester Fabric

Wood-plastic composite is an environmentally friendly material,due to its use of recycled thermoplastics and plant fibers.However,its surface lacks attractive aesthetic qualities.In this paper,a method of decorating wood fiber/high-density polyethylene(WF/HDPE)without adding adhesive was explored.Canvas or polyester fabrics were selected as the surface decoration materials.The influence of hot-pressing temperature and WF/HDPE ratio on the adhesion was studied.The surface bonding strength,water resistance,and surface color were evaluated,and observation within the infrared spectrum and under scanning electron microscopy was used to analyze the bonding process.The results showed that the fabric and WF/HDPE substrate could be closely laminated together depending on the HDPE layer accumulated on the WF/HDPE surface.The molten HDPE matrix penetrates canvas more easily than polyester fabric,and the canvasveneered composite shows a greater bonding strength than does the polyester fabric-veneered composite.A higher proportion of the thermoplastic component in the substrate improved the bonding.When the hot-pressing temperature exceeded 160°C,the fabric-veneered WF/HDPE panels had greater water resistance,although the canvas fabric changed more obviously in terms of fiber shape and color,compared with the polyester fabric.For the canvas fabric,140°C–160°C was a suitable hot-pressing temperature,whereas 160°C–180°C was more suitable for polyester fabric.The proportion of the thermoplastic component in the composite should be not less than 30%to achieve adequate bonding strength.

Biocomposites of Polylactic Acid Reinforced by DL-Lactic Acid-Grafted Microfibrillated Cellulose

Microfibrillated cellulose(MFC)is often added to polylactic acid(PLA)matrixes as a reinforcing filler to obtain fully-biodegradable composites with improved mechanical properties.However,the incompatibility between MFC and the PLA matrix limits the mechanical performance of MFC-reinforced PLA composites.In this paper,DL-lactic acid-grafted-MFC(MFC-g-DL)was used to improve the compatibility with PLA.Reinforced composites were prepared by melt extrusion and hot-cold pressing.The tensile strength of the PLA/MFC-g-DL composite increased by 22.1%compared with that of PLA after adding 1%MFC-g-DL.Scanning electron microscopy(SEM),differential scanning calorimetry(DSC),and dynamic thermomechanical analysis(DMA)were used to explore the enhancement mechanism.The energy dissipation in the MFC network and the improved compatibility between PLA and MFC-g-DL played important roles in the reinforcement.The SEM results showed that there was a closer combination between PLA and MFC-g-DL.The DSC results showed that the addition of cellulose changed the glass transition temperature,melting temperature,and crystallization temperature of PLA.The TG results showed that the initial and maximum decomposition temperature were lower than those of PLA.The ultraviolet spectra showed that the composite had good transparency at a low concentration of MFC-g-DL.

Improvement in the Performance of the Polylactic Acid Composites by Using Deep Eutectic Solvent Treated Pulp Fiber

As the most favorable alternative to petroleum-based polymers,polylactic acid(PLA)which is the most promising degradable polymer has attracted increasing attention.However,the addition of cellulose to improve its strength often results in a reduction in its toughness.In this work,microscale cellulose is first prepared from pulp fibers by using a deep eutectic solvent,and then is used as the reinforcement of PLA.A microcrystalline cellulose(MCC)/PLA sheet with uniform texture is obtained by the solution mixing,melt blending,hot-pressing and cold-pressing process.The effects of MCC on the crystallization,thermal stability and mechanical properties of the PLA matrix were studied.Upon the addition of 1%cellulose fiber,the tensile strength of MCC/PLA composite sheet increased by 27%,and the elongation at break did not shown an evident decrease.The strength enhancement mechanism was elucidated using scanning electron microscopy,differential scanning calorimetry,and dynamic thermomechanical analysis.The energy dissipation during the deformation process and the compatibility of AMCC and rougher surface of MCC play important role in the strength enhancement.Additionally,UV spectroscopy showed that the composite material absorbed some ultraviolet light.Our results show that the combined use of a deep eutectic solvent and solution mixing is an effective approach for improving the strength of PLA while maintaining its toughness.

Research on Ecological Corridor Planning of Lanzhou Yuzhong Ecological Innovation City from the Perspective of Ecological Civilization

The practice and research of ecological civilization is a focus of current planning and design,as well as a scientific strategy under the current situation of resource constraint,environmental degradation and ecosystem degradation.Urban elements such as buildings,green land,farmland,water systems and mountains can be connected by ecological corridors into a green ecological system design.At present,many ecological and environmental problems,such as urban heat island effect,fog and haze,automobile exhaust have a negative effect on the construction of social ecological environment.In order to build a new modern city with prosperous economy,beautiful environment and social civilization,scientific and efficient ecological corridors should be designed to improve the environmental quality of the eco-city,and promote the construction and development of ecological civilization and green cities.Based on the relevant research and specific practices of ecological corridors at home and abroad,combine the needs of the planning and construction of the Yuzhong Ecological Innovation City,and discuss on the connotation and characteristics of ecological corridors,and discuss the key elements of ecological corridor planning.This article will take the ecological corridor planning of Yuzhong Eco-Innovation City as an example.We design ecological corridor based on field investigation,literature and geographic information system..The planning and design of the ecological corridor in the planning area proposed in this paper can provide positive suggestion on the planning and design of the ecological corridor in other ecological innovation cities.

Radiation injury and gut microbiota-based treatment

The exposure to either medical sources or accidental radiation can cause varying degrees of radiation injury(RI).RI is a common disease involving multiple human body parts and organs,yet effective treatments are currently limited.Accumulating evidence suggests gut microbiota are closely associated with the development and prevention of various RI.This article summarizes 10 common types of RI and their possible mechanisms.It also highlights the changes and potential microbiota-based treatments for RI,including probiotics,metabolites,and microbiota transplantation.Additionally,a 5P-Framework is proposed to provide a comprehensive strategy for managing RI.

Cyber-Physical Resilience Enhancement for Power Transmission Systems with Energy Storage Systems

In a power system, when extreme events occur, such as ice storm, large scale blackouts may be unavoidable. Such small probability but high risk events have huge impact on power systems. Most resilience research in power systems only considers faults on the physical side, which would lead to overly idealistic results. This paper proposes a two-stage cyber-physical resilience enhancement method considering energy storage (ES) systems. The first stage calculates optimal planning of ES systems, and the second stage assesses resilience and enhancement of ES systems during the disaster. In the proposed model, cyber faults indirectly damage the system by disabling monitoring and control function of control center. As a result, when detection and response process of physical faults are blocked by cyber failures, serious load shedding occurs. Such a cyber-physical coupling mechanism of fault, response, restoration process is demonstrated in the modified IEEE Reliable Test System-79 (RTS-79). Simulation results show compared with the physical-only system, the cyber-physical system has a more accurate but degraded resilient performance. Besides, ES systems setting at proper place effectively enhance resilience of the cyber-physical transmission system with less load Shedding.

Identifiability Analysis of Load Model Parameters by Estimating Confidential Intervals

The identification of load model parameters from practical measurement data has become an essential method to build load models for power system simulation,analysis and control.In practical situations,the accuracy of the load model parameters identification results is impacted by data quality and measurement accuracy,which leads to the problem of identifiability.In this paper,an identifiability analysis methodology of load model parameters,by estimating the confidential intervals(CIs)of the parameters,is proposed.The load model structure and the combined optimization and regression method to identify the parameters are first introduced.Then,the definition and analysis method of identifiability are discussed.The CIs of the parameters are estimated through the profile likelihood method,based on which a practical identifiability index(PII)is defined to quantitatively evaluate identifiability.Finally,the effectiveness of the proposed analysis approach is validated by the case study results in a practical provincial power grid.The results show that the impact of various disturbance magnitudes,measurement errors and data length can all be reflected by the proposed PII.Furthermore,the proposed PII can provide guidance in data length selection in practical load model identification situations.

表达Elafin的益生菌Nissle 1917对小鼠实验性结肠炎的保护作用

目的构建能够表达人重组蛋白Elafin的益生菌大肠杆菌Nissle 1917(EcN),并探讨其对葡聚糖硫酸钠(DSS)诱导的急性小鼠结肠炎的保护作用。方法构建带有Elafin基因的重组质粒,将其转入感受态EcN,构建能够表达Elafin蛋白的益生菌EcN-Elafin。通过Western印迹证实该益生菌在体外成功表达Elafin。C57/BL6J小鼠随机分为4组:健康对照组(PBS组)、结肠炎组(DSS组)、野生型EcN(EcN-WT)治疗结肠炎组(EcN-WT组)、EcN-Elafin治疗结肠炎组(EcN-Elafin组)。每天同一时间测量小鼠体重、观察小鼠排便情况及计算疾病活动度指数(DAI)。小鼠处以安乐死后测量结肠长度,苏木精-伊红(HE)染色及组织病理学评分比较各组肠黏膜炎症程度,流式细胞术检测结肠固有层浸润中性粒细胞和巨噬细胞的比例,酶联免疫吸附法(ELISA)定量结肠组织中的肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6及趋化因子CXCL-1的蛋白表达水平。结果在EcN-Elafin的培养基上清和菌体沉淀中均能检测到Elafin蛋白。与DSS组相比,EcN-Elafin组和EcN-WT组小鼠体重减轻状况和DAI评分均明显改善。EcN-Elafin组小鼠结肠长度显著长于DSS组。EcN-Elafin组结肠炎组织学评分显著低于DSS组(5.3±2.3比9.3±1.4,P<0.05)。与DSS组小鼠相比,EcN-Elafin组小鼠结肠固有层浸润的中性粒细胞[(8.65±1.49)%比(17.60±2.16)%,P<0.01]和巨噬细胞[(3.79±0.26)%比(5.73±0.45)%,P<0.01]比例均显著降低。EcN-Elafin组和EcN-WT组结肠中TNF-α、IL-6、和CXCL-1蛋白质表达水平均显著低于DSS组。结论表达Elafin的益生菌EcN-Elafin能够显著减轻DSS诱导的急性小鼠结肠炎,对肠黏膜炎症具有保护作用,为临床炎症性肠病的治疗提供一种新的经济有效的方法。

A Genomic Variation Map Provides Insights into the Genetic Basis of Spring Chinese Cabbage (Brassica rapa ssp.pekinensis)Selection

Chinese cabbage is the most consumed leafy crop in East Asian countries.However,premature bolting induced by continuous low temperatures severely decreases the yield and quality of the Chinese cabbage, and therefore restricts its planting season and geographic distribution.In the past 40years,spring Chinese cabbage with strong winterness has been selected to meet the market demand.Here,we report a genome variation map of Chinese cabbage generated from the resequencing data of 194 geographically diverse accessions of three ecotypes.In-depth analyses of the selection sweeps and genome-wide patterns revealed that spring Chinese cabbage was selected from a specific population of autumn Chinese cabbage around the area of Shandong peninsula in northern China.We identified 23 genomic loci that underwent intensive selection,and further demonstrated by gene expression and haplotype analyses that the incorporation of elite alleles of VERNALISATION INSENTIVE 3.1(BrVIN3.1)and FLOWER LOCUS C 1(BrFLC1)is a determinant genetic source of variation during selection.Moreover,we showed that the quantitative response of BrVIN3.1 to cold due to the sequence variations in the cis elements of the BrVlN3.1 promoter significantly contributes to bolting-time variation in Chinese cabbage.Collectively, our study provides valuable insights into the genetic basis of spring Chinese cabbage selection and will facilitate the breeding of bolting-resistant Varieties by molecular-marker-assisted selection,transgenic or gene editingapproaches.

Macrophage-derived IL-1α promotes sterile inflammation in a mouse model of acetaminophen hepatotoxicity

The metabolic intermediate of acetaminophen(APAP)can cause severe hepatocyte necrosis,which triggers aberrant immune activation of liver non-parenchymal cells(NPC).Overzealous hepatic inflammation determines the morbidity and mortality of APAP-induced liver injury(AILI).Interleukin-1 receptor(IL-1R)signaling has been shown to play a critical role in various inflammatory conditions,but its precise role and underlying mechanism in AILI remain debatable.Herein,we show that NLRP3 inflammasome activation of IL-1βis dispensable to AILI,whereas IL-1α,the other ligand of IL-1R1,accounts for hepatic injury by a lethal dose of APAP.Furthermore,Kupffer cells function as a major source of activated IL-1αin the liver,which is activated by damaged hepatocytes through TLR4/MyD88 signaling.Finally,IL-1αis able to chemoattract and activate CD11b^(+)Gr-1^(+) myeloid cells,mostly neutrophils and inflammatory monocytes,to amplify deteriorated inflammation in the lesion.Therefore,this work identifies that MyD88-dependent activation of IL-1αin Kupffer cells plays a central role in the immunopathogenesis of AILI and implicates that IL-1αis a promising therapeutic target for AILI treatment.