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Unlocking the bacterial contact-dependent antibacterial activity to engineer a biocontrol alliance of two species from natural incompatibility to artificial compatibility

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Stress Biology 2021年第1期1卷 230-242页

作者： qianhua wu Bozhen Wang Xi Shen Danyu Shen Bingxin Wang Qinggang Guo Tao Li Xiaolong Shao Guoliang Qian College of Plant Protection Laboratory of Plant ImmunityKey Laboratory of Integrated Management of Crop Diseases and PestsNanjing Agricultural UniversityNo.1 WeigangNanjingJiangsu 210095People’s Republic of China Institute of Plant Protection Hebei Academy of Agricultural and Forestry SciencesIntegrated Pest Management Center of Hebei ProvinceKey Laboratory of IPM on Crops in Northern Region of North ChinaMinistry of Agriculture and Rural Affairs of ChinaBaoding 071000People’s Republic of China Shanghai Veterinary Research Institute Chinese Academy of Agricultural SciencesShanghai 200241People’s Republic of China

Plant growth-promoting rhizobacteria(PGPR)contain various biocontrol bacteria with broad-spectrum antimicrobial activity,and their single species has been extensively applied to control crop diseases.The development of complex biocontrol community by mixing two or more PGPR members together is a promising strategy to enlarge the efficacy and scope of biocontrol.However,an effective method to assess the natural compatibility of PGPR members has not yet been established to date.Here,we developed such a tool by using the bacterial contactdependent antibacterial activity(CDAA)as a probe.We showed that the CDAA events are common in two-species interactions in the four selected representative PGPRs,represented by the incompatible interaction of Lysobacter enzymogenes strain OH11(OH11)and Lysobacter antibioticus strain OH13(OH13).We further showed that the CDAA between OH11 and OH13 is jointly controlled by a contact-dependent killing device,called the type IV secretion system(T4SS).By deleting the respective T4SS synthesis genes,the T4SS in both strains was co-inactivated and this step unlocked their natural CDAA,resulting in an engineered,compatible mutant alliance that co-displayed antibacterial and antifungal activity.Therefore,this study reveals that releasing bacterial CDAA is effective to rationally engineer the biocontrol community.

关键词： PGPR Biocontrol Contact-dependent antibacterial activity T4SS Engineering

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黄河中游典型流域土地利用对径流的调控作用

水土保持研究 2024年第3期31卷 61-68,78页

作者：王倩华张攀王伟肖培青吴晓玲河海大学水文水资源学院南京210024 黄河水利委员会黄河水利科学研究院水利部黄土高原水土保持重点实验室郑州450003 河南省水土保持监测总站郑州450008

[目的]深入研究黄河中游不同土地利用对径流变化的调节效应及其阈值,对于山洪防治和流域高质量发展至关重要。[方法]以大理河流域为重点研究区域,分析其近20年来的土地利用变化特征,基于流域月尺度SWAT模型定量分析了土地利用变化对径... 详细信息

[目的]深入研究黄河中游不同土地利用对径流变化的调节效应及其阈值,对于山洪防治和流域高质量发展至关重要。[方法]以大理河流域为重点研究区域,分析其近20年来的土地利用变化特征,基于流域月尺度SWAT模型定量分析了土地利用变化对径流年内分配的影响;通过设置4种极端土地利用情况研究了不同土地利用类型对于汛期径流的影响;并通过设置12种不同的土地利用覆盖度情景,揭示了影响流域径流的土地利用的覆盖临界。[结果]大理河流域主要的土地利用方式为耕地、草地和林地,草地和林地对径流有抑制作用,耕地对径流存在促进作用,三者的影响系数分别为-0.125,-0.130,0.122。土地利用对径流的年内分配有一定的调控作用,但当土地利用变化较小时,这种调控作用不明显。土地利用覆盖度存在明显的边际效应,其下临界约为5%,草地的上临界为95%,林地的上临界为91%。[结论]由于流域内实际的植被条件较差,林草覆盖度仍处于较低水平,因此修复植被和适当地退耕、退草还林仍能对该流域的水土保持工作和防洪建设起到促进作用。

关键词： SWAT模型土地利用变化阈值大理河流域

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化学诱变提高植物抗逆性的研究进展

核农学报 2024年第2期38卷 274-281页

作者：吴正景职钤华刘素娟张昊安冰洁武静静龙圆李辰方河南科技大学园艺与植物保护学院河南洛阳471003

化学诱变是农业上一种传统的育种技术,在植物抗逆育种方面受到育种家的青睐,用于改善植物的抗寒、抗旱、耐盐碱性等育种方面的研究。植物组织培养技术是实现细胞或个体快速繁殖的有效途径。以上两种技术的结合,可有效提高突变的频率,人... 详细信息

化学诱变是农业上一种传统的育种技术,在植物抗逆育种方面受到育种家的青睐,用于改善植物的抗寒、抗旱、耐盐碱性等育种方面的研究。植物组织培养技术是实现细胞或个体快速繁殖的有效途径。以上两种技术的结合,可有效提高突变的频率,人为扩大植物遗传变异范围。近年来,化学诱变与生物技术结合在植物抗逆诱变育种方面展现出了积极的发展前景,对于植物新品种选育具有重要的实践意义。本研究综述了化学诱变的特点、常用化学诱变剂[主要是甲基磺酸乙酯(EMS)和叠氮化钠(NaN3)]的诱变机制、使用方法、诱变效果以及影响化学诱变的因素等,并介绍了化学诱变在植物抗逆育种领域中的新近研究进展。

关键词：化学诱变抗逆育种甲基磺酸乙酯(EMS) 叠氮化钠(NaN3) 植物诱变育种

Enhanced osteoarthritis therapy by nanoengineered mesenchymal stem cells using biomimetic CuS nanoparticles loaded with plasmid DNA encoding TGF-β1

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Bioactive Materials 2023年第1期19卷 444-457页

作者： Yu Cai Cuixi wu qianhua Ou Muhui Zeng Song Xue Jieli Chen Yao Lu Changhai Ding Clinical Research Center Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong510282China Orthopedic Center Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong510282China Guangdong Key Lab of Orthopedic Technology and Implant GuangzhouGuangdong510010China Department of Rheumatology and Immunology Arthritis Research InstituteThe First Affiliated Hospital of Anhui Medical UniversityHefeiAnhui230032China Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases Academy of OrthopedicsSouthern Medical UniversityGuangzhouGuangdong510630China Menzies Institute for Medical Research University of TasmaniaHobartTasmania7000Australia

Mesenchymal stem cells(MSCs)therapy shows the potential benefits to relieve clinical symptoms of osteoarthritis(OA),but it is uncertain if it can repair articular cartilage lesions-the main pathology of OA.Here,we prepared biomimetic cupper sulfide@phosphatidylcholine(CuS@PC)nanoparticles(NPs)loaded with plasmid DNA(pDNA)encoding transforming growth factor-beta 1(TGF-β1)to engineer MSCs for enhanced OA therapy via cartilage regeneration.We found that the NPs not only promoted cell proliferation and migration,but also presented a higher pDNA transfection efficiency relative to commercial transfection reagent lipofectamine 3000.The resultant CuS/TGF-β1@PC NP-engineered MSCs(termed CTP-MSCs)were better than pure MSCs in terms of chondrogenic gene expression,glycosaminoglycan deposition and type II collagen formation,favoring cartilage repair.Further,CTP-MSCs inhibited extracellular matrix degradation in interleukin-1β-induced chondrocytes.Consequently,intraarticular administration of CTP-MSCs significantly enhanced the repair of damaged cartilage,whereas pure MSCs exhibited very limited effects on cartilage regeneration in destabilization of the medial meniscus(DMM)surgical instability mice.Hence,this work provides a new strategy to overcome the limitation of current stem cell therapy in OA treatment through developing more effective nanoengineered MSCs.

关键词： Osteoarthritis Stem cell therapy Cartilage regeneration Cupper sulfide nanoparticles Gene delivery

类风湿关节炎患者乙型肝炎病毒感染状态及临床特征分析

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中华医学杂志 2024年第3期104卷 205-211页

作者：郑湖伟欧阳志明潘婕贾霈雯邹耀威马剑达陈乐锋李谦华吴滔戴冽中山大学孙逸仙纪念医院风湿免疫科广州510120

目的了解类风湿关节炎(RA)患者的乙型肝炎病毒(HBV)感染状态及其与临床特征的关系。方法本研究为横断面研究。回顾性纳入2001年1月至2023年2月就诊于中山大学孙逸仙纪念医院风湿免疫科的RA患者,收集患者临床资料,包括年龄、性别、病程... 详细信息

目的了解类风湿关节炎(RA)患者的乙型肝炎病毒(HBV)感染状态及其与临床特征的关系。方法本研究为横断面研究。回顾性纳入2001年1月至2023年2月就诊于中山大学孙逸仙纪念医院风湿免疫科的RA患者,收集患者临床资料,包括年龄、性别、病程、吸烟、RA疾病活动、功能及放射学评估指标、HBV筛查及肝功能指标等。依HBV感染情况,将患者分为慢性HBV感染、既往HBV感染和无HBV感染组,分析各组感染分布情况和RA患者的临床特征。结果共纳入1941例RA患者,其中1461例(75.3%)完成HBV筛查,其中男335例(22.9%),女1126例(77.1%),年龄为(55.4±13.1)岁。148例(10.1%)RA患者合并慢性HBV感染,其中男性合并慢性HBV感染的发生率高于女性[14.6%(49/335)比8.8%(99/1126),P<0.001],尤其是在1970至1979年[20.0%(7/35)比8.5%(17/201),P=0.037]和1980至1989年[31.8%(7/22)比10.5%(14/133),P=0.007]出生的RA患者。148例慢性HBV感染者中,有5例(3.4%)慢性乙型肝炎,2例(1.4%)HBV相关肝硬化和1例(0.7%)肝细胞癌。841例(57.6%)RA患者合并既往HBV感染。472例(32.3%)RA患者无HBV感染,其中267例(56.6%)抗乙型肝炎表面抗体阴性。所有RA患者中,15例(1.0%)有肝功能异常,其中7例为药物性肝损伤,5例为慢性乙型肝炎,2例为脂肪肝,1例为原发性胆汁性胆管炎。结论慢性HBV感染仍是我国RA患者的常见合并症,感染率10.1%,临床应加强对HBV感染的筛查与管理。

关键词：类风湿关节炎乙型肝炎病毒患病率

高响应交流永磁伺服系统快速电流环带宽扩展方法

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浙江理工大学学报（自然科学版） 2024年第1期51卷 91-99页

作者：丁签华纪科辉吴昊熊卫华浙江理工大学信息科学与工程学院杭州310018

交流永磁伺服控制系统中现有电流采样和脉冲宽度调制(Pulse width modulation,PWM)占空比更新的方法延迟时间较长,在一定程度上会影响电机的电流环带宽和动态特性;针对该问题,建立了电流环闭环系统数学模型,分析了电流环的内部延迟和影... 详细信息

交流永磁伺服控制系统中现有电流采样和脉冲宽度调制(Pulse width modulation,PWM)占空比更新的方法延迟时间较长,在一定程度上会影响电机的电流环带宽和动态特性;针对该问题,建立了电流环闭环系统数学模型,分析了电流环的内部延迟和影响电流环带宽的因素,在此基础上提出了一种通过改进电流采样与PWM更新时间的电流环带宽扩展方法。该方法通过提前PWM占空比更新时机来降低电流采样和PWM占空比更新之间的延迟,减小信号传输滞后,从而扩展电流环系统的闭环带宽,提高系统响应速度。仿真与实验结果表明,相比现有电流采样方法,采用新方法的交流永磁伺服控制系统的电流环具有更宽的带宽和更高的动态响应能力,从而提高了交流伺服系统的动态响应能力和稳态精度。该方法可为交流伺服系统在机器人、高端智能装备等对响应速度和定位精度要求较高领域的应用提供参考。

关键词：交流永磁伺服快速电流环电流采样占空比更新电流环带宽扩展

Effects of Different Farming Methods and Their Effects on Soil Physicochemical Properties of Guilin Maojian Tea Gardens

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Agricultural Biotechnology 2018年第5期7卷 186-190页

作者： Lingyun ZHANG Shuyi LI Sisi Qin Changjian JIANG Qifa LONG Min SU Chusheng LIU qianhua wu Guangxi Guilin Tea Research Institute Guilin 541004China

In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties of tea garden soil were studied through the modification of the test sites with the non-farming land as the control. The results showed that human farming, mini-tiller farming and crawler tractor farming could improve the physical and chemical properties of soil. After farming, the soil had good water retention but low moisture content compared to the control group, while the soil bulk density and hardness value were significantly lower than those of the control, and the porosity of soil was significantly higher than that of contrast. With the passage of time, soil bulk density and hardness value gradually increased after farming, while the porosity of soil decreased gradually. There were great differences in the effects, efficiencies and costs of different farming methods. Crawler tractor had the best and most stable farming effect, and the operation efficiency was 10 times that of human farming while the cost was only 0.39 times of human farming. Therefore, it was feasible to adopt mini-tiller or crawler tractor to carry out mechanical farming of Guilin Maojian tea garden, which provided theoretical references for the soil property improvement using mechanical farming and was favorable for promoting the popularization of farming machines and the acceleration of mechanization of tea gardens. But for tea plantations that are intended to be mechanized, apart from the mechanical and technical personnel to be configured in place, the site conditions, planting modes and mechanical way reservation of tea garden should be planned accordingly. It is recommended to select flat or gentle slope for reclamation, and preference is given to non-sexual tea tree varieties with big line spacing over 180 cm long. Moreover, the main road construction should be more than 3.0 m, and trunk road 2.0 m or above. And isolat

关键词： Guilin Maojian tea Tea garden Farming methods Soil Physical and chemical properties

Thermal shock resistance enhancement by improved interfacial bonding for carbon/aluminium composites

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High Voltage 2022年第5期7卷 960-967页

作者： Wenfu Wei Zhanglin Huang Guofeng Yin Zefeng Yang Xiaobo Li Haozi Zuo Qin Deng Guizao Huang Junwen Ren qianhua Liao Yan Yang Guangning wu School of Electrical Engineering Southwest Jiaotong UniversityChengduChina Handley Electronic Co. LtdChangzhouChina College of Electrical Engineering Sichuan UniversityChengduChina School of Electrical&Electronic Engineering Nanyang Technological UniversitySingaporeSingapore

Carbon/aluminium(C/Al)composites have the advantages of low density and high electrical conductivity,which have potential applications in aerospace,rail transportation and other fields.However,the unstable bonding of the C/Al interface and significant thermal expansion differences have resulted in risks of the composites'failure once suffering from severe thermal shock.In this work,the C/Al composites were prepared by the pressure impregnation method,and silicon(Si)was added to overcome the problems of C/Al non-wettability and thermal expansion differences.The effects of mass fractions of doped silicon on the mechanical properties,electrical conductivity and thermal shock resistance of C/Al composites were also examined.Results show that the formed SiC interlayer has effectively enhanced the interfacial bonding and reduced the differences in the thermal expansion coefficient of each component.As a result,the thermal shock resistance of the composites has been remarkably improved,and the flexural strength could remain 90%of the original level after the thermal shock test,compared with 50%of that without Si doping.

关键词： composites bonding shock

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硬顶法压井技术在渤海油田的应用

河南科技 2024年第7期51卷 42-45页

作者：罗黎敏廖前华张兴华朱鹏飞吴智文中海石油(中国)有限公司天津分公司天津300452 中海油能源发展股份有限公司工程技术分公司天津300452

【目的】海上油田钻井作业面临的地质条件、井下工况日趋复杂,部分井无法采用常规的压井方法实施压井,不仅增加了作业工期,而且可能形成井控风险。为了实现渤海油田复杂井安全压井,避免井控事故发生,在渤海油田应用了硬顶法压井技术。... 详细信息

【目的】海上油田钻井作业面临的地质条件、井下工况日趋复杂,部分井无法采用常规的压井方法实施压井,不仅增加了作业工期,而且可能形成井控风险。为了实现渤海油田复杂井安全压井,避免井控事故发生,在渤海油田应用了硬顶法压井技术。【方法】针对渤海油田的特殊工况,分析硬顶法压井技术适用的工况,指出硬顶法压井技术相关计算原则。通过分析硬顶法压井应用实例,提出该技术应用时的注意事项。【结果】研究结果表明,硬顶法压井技术适用于关井钻头离井底远、地层含有毒有害气体、钻具或钻头水眼堵塞、关井后发生井漏导致喷漏同存、长裸眼段测试后压井等五个方面,计算原则可从压井液密度计算、压井排量选择和过程计算等三个方面考虑。针对该技术在渤海油田A井的应用实例,提出了井口关键设备耐压等级的确定、上层套管鞋处地层承压能力、设备的选择、薄弱地层的处理四个方面需要注意的事项。【结论】研究结果明确了硬顶法压井技术使用原则和注意事项,可为硬顶法压井技术在复杂海上油田应用提供技术支持与参考。

关键词：渤海油田压井钻井工程井控溢流