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Functional characterization of a Niemann-Pick type C2 protein in the parasitoid wasp Micropfitis mediator

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Insect Science 2018年第5期25卷 765-777页

作者： Yao zheng Shan-Ning Wang yong Peng Zi-Yun Lu Shuang Shan Ye-Qing Yang Rui-Jun Li yong-Jun zhang Yu-Yuan Guo State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing China College of Plant Protection Agricultural University of Hebei Baoding Hebei Province China IPM Center of Hebei Province Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China Ministry of Agriculture Plant Protection Institute Hebei Academy of Agricultural and Forestry Sciences Baoding Hebei Province China College of Plant Protection China Agricultural University Beijing China

Niemann-Pick type C2 （NPC2） is a type of small soluble protein involved in lipid metabolism and triglyceride accumulation in vertebrates and arthropods. Recent stud- ies have determined that NPC2 also participates in chemical communication of arthropods. In this work, two novel NPC2 proteins （MmedNPC2a and MmedNPC2b） in Microplitis mediator were identified. Real-time quantitative PCR （qPCR） analysis revealed that Mmed- NPC2a was expressed higher in the antennae than in other tissues of adult wasps compared with MmedNPC2b. Subsequent immunolocalization results demonstrated that NPC2a was located in the lymph cavities of sensilla placodea. To further explore the binding charac- terization of recombinant MmedNPC2a to 54 candidate odor molecules, a fluorescence binding assay was performed. It was found MmedNPC2a could not bind with selected fatty acids, such as linoleic acid, palmitic acid, stearic acid and octadecenoic acid. How- ever, seven cotton volatiles, 4-ethylbenzaldehyde, 3,4-dimethylbenzaldehyde, fl-ionone, linalool, m-xylene, benzaldehyde and trans-2-hexen-l-al showed certain binding abilities with MmedNPC2a. Moreover, the predicted 3D model of MmedNPC2a was composed of seven r-sheets and three pairs of disulfide bridges. In this model, the key binding residues for oleic acid in CjapNPC2 of Camponotus japonicus, Lue68, Lys69, Lys70, Phe97, Thr103 and Phe127, are replaced with Phe85, Ser86, His87, Leu113, Tyr119 and Ile143 in MmedNPC2a, respectively. We proposed that MmedNPC2a in M. mediator may play roles in perception of plant volatiles.

关键词： binding ability chemical communication immunolocalization Microplitismediator NPC2 protein 3D model

Influence of double-inlet design on the flow-head characteristics of axial-flow pump

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Journal of Hydrodynamics 2021年第4期33卷 763-772页

作者： yong-sheng Zhou Hua zhang Bin Chen School of Mechanical Engineering Hefei University of TechnologyHefei230009China College of Hydraulic Science and Engineering Yangzhou UniversityYangzhou225127China School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing210044China

The internal flow field of an axial-flow pump under low flow rate conditions is extremely turbulent. The unstable flow region is formed due to the tip leakage and the rotating stall, and is distinguished by a saddle patterned zone in its flow-head curve that demonstrates restrictions in its workable flow range. It is therefore important to understand and improve the operational characteristics of an axial-flow pump under low flow rate conditions. In this study, experiments are performed for the performances of an axial-flow pump at the flow rate in a range between 0.8Qd and 1.2Qd, with the internal flow field measured by the particle image velocimetry (PIV), and with the pump performances and the internal flow field simulated by the Ansys CFX. The simulation results agree well with the experimental results. From the predicted heads at the flow rate in the range between 0.1Qd and 0.7Qd by the numerical simulation, the complete flow-head curves are obtained. The streamlines and the velocity contours in the region in front of the impeller leading edge under different flow conditions are analyzed. By adopting the double-inlet structures, the flow-head characteristics are studied by varying the values of δ and σ respectively, where δ denotes the gap between the inner cylinder end and the impeller leading edge, and σ denotes the gap between the inner cylinder and the outer cylinder. The findings indicate that with the double-inlet design, the velocity distribution can be effectively improved in the region in front of the impeller leading edge, as well as the head performance under the low flow rate conditions, and the positive slope value of the head curve is reduced in the unstable flow range. The optimal δ and σ values are determined.

关键词： Double-inlet particle image velocimetry(PIV) tip leakage numerical simulation axial-flow pump

面向微光学元件表面形貌测量的涡旋相移数字全息技术

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中国光学（中英文） 2024年第4期17卷 852-861页

作者：薛一梦刘丙才潘永强房鑫萌田爱玲张瑞轩西安工业大学光电工程学院陕西西安710021 西安工业大学陕西省薄膜技术与光学检测重点实验室陕西西安710021

非接触、无损害的相移数字全息技术对微光学元件检测具有独特优势。因传统的相移数字全息技术需要对相移器进行精细控制和繁琐校准,同时其光路易受到机械振动干扰,导致全息再现像的质量降低。本文借助涡旋光特殊的相位分布,提出了一种... 详细信息

非接触、无损害的相移数字全息技术对微光学元件检测具有独特优势。因传统的相移数字全息技术需要对相移器进行精细控制和繁琐校准,同时其光路易受到机械振动干扰,导致全息再现像的质量降低。本文借助涡旋光特殊的相位分布,提出了一种基于涡旋相移数字全息的微光学元件表面形貌测量方法。该方法利用螺旋相位板调制涡旋相位,引入高精度相移。基于构建的涡旋相移数字全息显微实验装置,采用干涉极值法确定了相移干涉图之间的真实相移量,并对螺旋相位板的旋转角度与相移量的关系进行标定,实验验证了涡旋相移的可行性;对微透镜阵列进行了重复测量实验,将测试结果与ZYGO白光干涉仪的测试结果进行比较。结果表明:测量得到单个微透镜的平均纵向矢高为12.897μm,平均相对误差为0.155%。所提方法可以实现对被测微光学元件表面形貌的高精度测量,具有易操作、稳定可靠、准确性高等优点。

关键词：涡旋相移数字全息显微螺旋相位板相位重建

Effect of homogenization annealing on internal residual stress distribution and texture in ME21 magnesium alloy extruded plates

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Journal of Magnesium and Alloys 2019年第1期7卷 186-192页

作者： yong Lian Pengfei Ji Jin zhang Xiaomin Yuan Weisheng Xu yongle Zhao Jiahao Mo Lin zheng Shitao Dou Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Corrosion Erosion and Surface TechnologyBeijing 100083China Capital Aerospace Machinery Company Beijing 10076China Institute of Southwest Technology and Engineering Chongqing 400039China

The distribution of residual stresses through thickness of 5 mm-thick ME21 magnesium alloy extruded plates was analyzed non-destructively using short-wavelength X-ray diffraction(SWXRD),and the effect of homogenization annealing before extrusion on the residual stress was *** classic d 0 method with an annealed stress-free reference specimen was employed to determine the residual stress of the extruded *** residual stress results showed that the gradient of residual stress in the transverse direction was larger than that of the extrusion *** homogenization process prior to extrusion weaken the formed sample’s *** maximum residual stress of the as-extruded plate was reduced,and the residual stress distribution was homogenized.

关键词： ME21 magnesium alloy Homogenization annealing Residual stress Short-wavelength X-ray diffraction

MR颅颈一体化高分辨血管壁成像定量分析在脑卒中相关血管床斑块负荷中应用

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中国临床医学影像杂志 2024年第1期35卷 11-16页

作者：郑艳龙吴丽鹏张杨张曦赵启利王秋艳廊坊市人民医院磁共振/CT科河北廊坊065000

目的:探究MR颅颈一体化高分辨血管壁成像定量分析在脑卒中相关血管床斑块负荷中应用。方法:选取2018年12月—2020年12月院内诊治缺血性脑卒中患者100例作为研究组,无症状危险人群50例和健康志愿者50例作为对照组,均接受平扫及增强颅颈... 详细信息

目的:探究MR颅颈一体化高分辨血管壁成像定量分析在脑卒中相关血管床斑块负荷中应用。方法:选取2018年12月—2020年12月院内诊治缺血性脑卒中患者100例作为研究组,无症状危险人群50例和健康志愿者50例作为对照组,均接受平扫及增强颅颈一体化血管壁成像。记录研究组缺血侧和非缺血侧颈动脉血管壁参数,并以是否发生脑组织不可逆死亡分为良好预后组与不良预后组,分析2组缺血侧颈动脉管壁参数、对疾病预后价值、与美国国立卫生研究院卒中量表(NIHSS)相关性。随访对照组2年,以是否发生缺血性脑卒中分为疾病组和正常组,分析2组颈动脉管壁参数及其预测价值。结果:缺血侧管腔面积小于非缺血侧,血管总面积、管壁面积、管壁标准化指数大于非缺血侧(P<0.05)。良好预后组管腔面积大于不良预后组,血管总面积、管壁面积、管壁标准化指数小于不良预后组(P<0.05)。颈动脉管壁参数联合检测缺血性脑卒中预后ROC曲线下面积AUC(0.824)最大。研究组管腔面积与NIHSS呈负相关关系(P<0.05)。疾病组管腔面积小于正常组,血管总面积、管壁面积、管壁标准化指数大于正常组(P<0.05)。颈动脉管壁参数联合检测无症状危险人群缺血性脑卒中发病ROC曲线下面积AUC(0.838)最大。结论:颈动脉管壁参数对缺血性脑卒中预后及无症状危险人群缺血性脑卒中发病具有较高预测价值,同时管腔面积越大其神经功能损伤越严重。

关键词：卒中磁共振成像

Directed evolution of the fusion enzyme for improving astaxanthin biosynthesis in Saccharomyces cerevisiae

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Synthetic and Systems Biotechnology 2023年第1期8卷 46-53页

作者： yong-Wen Ding Chuan-Zhen Lu Yan zheng Han-zhang Ma Jin Jin Bin Jia Ying-Jin Yuan Frontier Science Center for Synthetic Biology(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

catalyzed byβ-carotene hydroxylase(crtZ)andβ-carotene ketolase(crtW)decreases the content of the ***,we exploited directed evolution of the fusion of crtZ and crtW for improving astaxanthin biosynthesis in Saccharomyces *** results demonstrated that the fusion enzyme of crtZ-crtW with 2 X GGGGS peptides linker can effectively reduce the accumulation of intermediates and improves the content of *** with the control strain,the fusion enzyme of ketase and hydroxylase reduced zeaxanthin and canthaxanthin by 7 and 14 times and increased astaxanthin by 1.6 times,***,9 variant fusion mutants with improved astaxanthin production were generated through directed *** these dominant mutants generated a variant,L95S+I206L,which increased the astaxanthin content of 3.8 times than the control *** AlphaFold2 assisted structural analysis indicated that these two mutations alter the interaction between the substrate and the enzymes *** research provided an efficient idea to reduce the accumulation of the intermediate products in complex biosynthesis pathway.

关键词： Astaxanthin Directed evolution Fusion enzyme Saccharomyces cerevisiae Synthetic biology

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褐藻胶的酶法降解及其产物的体外免疫活性

食品科学 2024年第2期45卷 89-96页

作者：章倩戚慧敏卞斌马俊美赖晨欢黄曹兴凌喆勇强南京林业大学江苏省林业资源高效加工利用协同创新中心江苏南京210037

本研究以褐藻胶为底物,探究其在褐藻胶酶法降解过程中的分子质量变化以及酶法降解制备褐藻胶低聚糖的工艺参数,并在此基础上,评价了不同分子质量褐藻胶酶解产物的体外免疫活性。结果表明,褐藻胶经褐藻胶裂解酶降解后分子质量显著下降,... 详细信息

本研究以褐藻胶为底物,探究其在褐藻胶酶法降解过程中的分子质量变化以及酶法降解制备褐藻胶低聚糖的工艺参数,并在此基础上,评价了不同分子质量褐藻胶酶解产物的体外免疫活性。结果表明,褐藻胶经褐藻胶裂解酶降解后分子质量显著下降,通过乙醇分级分离可获得3种不同分子质量的降解产物,其重均分子质量分别为13.4、5.73kDa和3.85kDa。单因素试验优化获得酶法制备褐藻胶低聚糖的最适工艺参数为pH7.0、褐藻胶裂解酶用量15U/g(底物质量计)、酶解时间24h,此时,褐藻胶低聚糖得率为28.05%。利用小鼠巨噬细胞模型对褐藻胶及其3种分子质量降解产物的体外免疫活性进行评价,发现褐藻胶及其酶解产物均具有一定的免疫增强活性,且重均分子质量为5.73kDa的酶解组分免疫增强活性最好,优于褐藻胶低聚糖。同时,通过添加巨噬细胞受体蛋白Toll样受体4(Toll-like receptor 4,TLR4)的阻断剂(TAK-242),验证了褐藻胶酶解产物通过诱导巨噬细胞TLR4的分泌,引起级联反应,增加NO、肿瘤坏死因子-α和白细胞介素6的分泌,从而调节巨噬细胞免疫活性。研究结果可为褐藻胶高值化利用提供理论依据。

关键词：褐藻胶低聚糖免疫活性分子质量褐藻胶酶解产物细胞因子

MoS2-graphene in-plane contact for high interfacial thermal conduction

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Nano Research 2017年第9期10卷 2944-2953页

作者： Xiangjun Liu Junfeng Gao Gang zhang yong-Wei zhang Institute of High Performance Computing A＊STAR Singapore 138632 Singapore

Recent studies have indicated that two-dimensional (2D) MoS2 exhibits low in-plane and inter-plane thermal conductivities. This poses a significant challenge to heat management in MoS2-based electronic devices. To address this challenge, we have designed MoS2-graphene interfaces that fully utilize graphene, a 2D material that exhibits very high thermal conductivity. First, we performed ab initio atomistic simulations to understand bonding and structural stability at the interfaces. The interfaces that we designed, which were connected via strong covalent bonds between Mo and C atoms, were energetically stable. We then performed molecular dynamics simulations to investigate interfacial thermal conductance in these materials. Surprisingly, the interfacial thermal conductance was high and comparable to those of covalently bonded graphene-metal interfaces. Importantly, each interfacial Mo–C bond served as an independent thermal channel, enabling modulation of the interfacial thermal conductance by controlling the Mo vacancy concentration at the interface. The present work provides a viable heat management strategy for MoS2-based electronic devices.

关键词： MoS 2 graphene interfacial thermal conductance thermal management

Assessing Soil Erosion Rates on Manually-Tilled Hillslopes in the Sichuan Hilly Basin Using ^(137)Cs and ^(210)Pb_(ex) Measurements

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Pedosphere 2007年第3期17卷 273-283页

作者： zheng Jin-Jun HE Xiu-Bin D. WALLING zhang Xin-Bao D. FLANAGAN QI yong- Qing Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 （China） Graduate University of the Chinese Academy of Sciences Beijing 100049 （China） Department of Geography University of Exeter Exeter EX4 4RJ （UK） State Key laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of SciencesXi＇an 710075 （China） USDA-ARS National Soil Erosion Research Laboratory West Lafayette Indiana 47907 （USA） Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101（China）

Purple soils are widely distributed in the Sichuan Hilly Basin and are highly susceptible to erosion, especially on the cultivated slopes. Quantitative assessment of the erosion rates is, however, difficult due to small size of the plots of the manually-tilled land, the complex land use, and steep hillslopes. ^137Cs and ^210Pbex （excess ^210Pb） tracing techniques were used to investigate the spatial pattern of soil erosion rates associated with slope-land under hoe tillage in Neijiang of the Sichuan Hilly Basin. The ^137Cs and ^210Pbex inventories at the top of the cultivated slope were extremely low, and the highest inventories were found at the bottom of the cultivated slope. By combining the erosion rates estimates provided by both ^137Cs and 21~Pbex measurements, the weighted mean net soil loss from the study slope was estimated to be 3 100 t km^-2 year^-1, which was significantly less than 6 930 t km^-2 year^-1 reported for runoff plots on a 10° cultivated slope at the Suining Station of Soil Erosion. The spatial pattern of soil erosion rates on the steep agricultural land showed that hoe tillage played an important role in soil redistribution along the slope. Also, traditional farming practices had a significant role in reducing soil loss, leading to a lower net erosion rate for the field.

关键词： ^137Cs hoe tillage, ^210Pbex purple soil soil erosion