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Biosynthetic pathway of prescription cucurbitacin IIa and high-level production of key triterpenoid intermediates in engineered yeast and tobacco

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Plant Communications 2024年第6期5卷 154-172页

作者： Geng Chen Zhaokuan Guo yanyu shu Yan Zhao Lei Qiu Shaofeng Duan Yuan Lin Simei He Xiaobo Li Xiaolin Feng Guisheng Xiang Bo Nian Yina Wang Zhiyuan Li Chongkang Yang Yang Shi Yingchun Lu Guanze Liu Shengchao Yang Guanghui Zhang Bing Hao State Key Laboratory of Conservation and Utilization of Bio-resources in Yunnan The Key Laboratory of Medicinal Plant Biology of Yunnan ProvinceNational&Local Joint Engineering Research Center on Germplasms Innovation&Utilization of Chinese Medicinal Materials in Southwest ChinaYunnan Agricultural UniversityKunming 650201China Yunnan Characteristic Plant Extraction Laboratory KunmingYunnan 650106China

Cucurbitacin IIa is a triterpenoid isolated exclusively from Hemsleya plants and a non-steroidal anti-inflammatory drug that functions as the main ingredient of prescription Hemslecin capsules and tablets in *** biology provides new strategies for production of such valuable cucurbitacins at a large scale;however,the biosynthetic pathway of cucurbitacin IIa has been unknown,and the heterologous production of cucurbitacins in galactose medium has been expensive and low *** this study,we characterized the functions of genes encoding two squalene epoxidases(HcSE1-2),six oxidosqualene cyclases(HcOSC1-6),two CYP450s(HcCYP87D20 and HcCYP81Q59),and an acyltransferase(HcAT1)in cucurbitacin IIa biosynthesis by heterologous expression in Saccharomyces cerevisiae and Nicotiana *** achieved high-level production of the key cucurbitacin precursor 11-carbonyl-20b-hydroxy-Cuol from glucose in yeast via modular engineering of the mevalonate pathway and optimization of P450 expression *** resulting yields of 46.41 mg/l 11-carbonyl-20b-hydroxy-Cuol and 126.47 mg/l total cucurbitacin triterpenoids in shake flasks are the highest yields yet reported from engineered ***,production of 11-carbonyl-20b-hydroxy-Cuol by transient gene expression in tobacco resulted in yields of 1.28 mg/g dry weight in *** work reveals the key genes involved in biosynthesis of prescription cucurbitacin IIa and demonstrates that engineered yeast cultivated with glucose can produce high yields of key triterpenoid *** describe a low-cost and highly efficient platform for rapid screening of candidate genes and high-yield production of pharmacological triterpenoids.

关键词： cucurbitacin IIa oxidosqualene cyclase OSC 11-carbonyl-20b-hydroxy-Cuol Saccharomyces cerevisiae Nicotiana benthamiana Hemsleya chinensis

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Effect of Ni content on the wear behavior of Al-Si-Cu-Mg-Ni/SiC particles composites

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 374-383页

作者： yanyu Liu Lina Jia Wenbo Wang Zuheng Jin Hu Zhang School of Materials Science and Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315100China Qingdao Research Institute of Beihang University Qingdao 266000China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

In recent years,the addition of Ni has been widely acknowledged to be capable of enhancing the mechanical properties of Al-Si ***,the effect of Ni on the wear behaviors of Al-Si alloys and Al matrix composites,particularly at elevated temperat-ures,remains an understudied *** this study,Al-Si-Cu-Mg-Ni/20wt%SiC particles(SiCp)composites with varying Ni contents were prepared by using a semisolid stir casting *** effect of Ni content on the dry sliding wear behavior of the prepared compos-ites was investigated through sliding tests at 25 and 350℃.Results indicated that theθ-Al_(2)Cu phase gradually diminished and eventually disappeared as the Ni content increased from 0wt%to 3wt%.This change was accompanied by the formation and increase inδ-Al_(3)CuNi andε-Al_(3)Ni phases in *** hardness and ultimate tensile strength of the as-cast composites improved,and the wear rates of the composites decreased from 5.29×10^(−4)to 1.94×10^(−4)mm^(3)/(N∙m)at 25℃and from 20.2×10^(−4)to 7×10^(−4)mm^(3)/(N∙m)at 350℃with the increase in Ni content from 0wt%to 2wt%.The enhancement in performance was due to the presence of strengthening network structures and additional Ni-containing phases in the ***,the wear rate of the 3Ni composite was approximately two times higher than that of the 2Ni composite due to the fracture and debonding of theε-Al_(3)Ni *** wear,delamination wear,and oxidation wear were the predominant wear mechanisms of the investigated composites at 25℃,whereas delamination wear and oxid-ation wear were dominant during sliding at 350℃.

关键词： Al matrix composite microstructure sliding test high temperature wear mechanism

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Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

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Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU yanyu SONG Wei FU Xiaoguo SONG Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

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Charge Accumulation Characteristics of SF6-Epoxy Interface Under Negative Repetitive Nanosecond Pulses

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1808-1815页

作者： Shaocong Wu Geng Chen Yuming Shao Hao Xu Xuanning Zhang yanyu Liang Youping Tu State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

Repetitve nanosecond impulses in gas-insulated metal-enclosed switchgear (GIS) are likely to trigger inside flashover. Interface charges on the spacer in GIS are considered one of the main factors damaging insulation performance and may be induced by overvoltage. For good understanding of insulation failures, accumulation characteristics of charges between SF6 and epoxy spacers under repetitive nanosecond impulses are investigated. It can be found under nanosecond impulses, the charge source in gas volume contributes to interface charge accumulation predominantly. Interface charges will be promoted by impulse number and amplitude. Accumulation processes are analyzed based on runaway electrons mechanism. When impulse amplitude exceeds a threshold value, discharge in the gas volume turns to a runaway mode. A runaway electron leads to the interface charge accumulation. Affected by motion of the runaway electrons, the potential peak gradually moves close to the grounded electrode when impulse amplitude is raised. Meanwhile, increasing impulse number can enhance surface potential. Surface potential will reach saturation eventually. However, memory effect of the repetitive impulse discharge makes the half-peak width of the surface potential at the interface change little. Design of GIS gas-solid insulations can refer to this research.

关键词： GIS interface charge repetitive nano-second pulse SF6

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Replacement of fish meal with cottonseed protein concentrate in Chinese mitten crab(Eriocheir sinensis): Nutrient digestibility, growth performance, free amino acid profile, and expression of genes related to nutrient metabolism

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Animal Nutrition 2024年第2期17卷 447-462页

作者： Xinting Liu Danyang Zou Yizhu Wang Yutong Zhuang Yang Liu yanyu Li Zhenzhu Sun Chaoxia Ye Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring Institute of Modern Aquaculture Science and Engineering School of Life Science South China Normal University

This study aimed to investigate the application of cottonseed protein concentrate(CPC) in Chinese mitten crabs(Eriocheir sinensis). First, the apparent digestibility coefficient(ADC) of CPC, fish meal and soybean meal were compared in crabs(21.72 ± 0.33 g). The protein ADC of CPC was 90.42%, which was significantly higher than that of soybean meal(83.16%)(P < 0.05). The ADC of Phe, Cys and Glu of CPC were significantly higher than those of fish meal, while the ADC of Ile, Leu, Lys, Met, Thr and Ala of CPC were significantly lower(P < 0.05). Second, we investigated the effects of fish meal substitution by CPC on growth performance, free amino acid profile, and expression of genes related to nutrient metabolism in crabs. Six diets were formulated by replacing 0%, 15%, 30%, 45%, 60% and 75% fish meal with CPC, namely FM, CPC15, CPC30, CPC45, CPC60, and CPC75. A total of 630 crabs(1.68 ± 0.00 g) were randomly divided into 18 tanks(3 tanks per group) and fed 3 times daily for 9 weeks. Results showed that CPC75 group significantly reduced growth performance, feed conversion efficiency, and free Ile, Leu, Lys, Met, and Thr contents in muscle(P < 0.05). The contents of free amino acids(Arg, His, Ile, Leu, Lys, Met, Phe, Thr, Val,Ala, Cys, Glu, Gly, Ser and Tyr) in hepatopancreas decreased linearly with the increase of dietary CPC level(P < 0.05). The substitution of more than 45% fish meal with CPC significantly decreased the concentration of delicious amino acids(Ala, Glu and Gly) in hepatopancreas(P < 0.05), which might adversely affect crab flavor. The expression of genes related to antioxidant capacity, protein transport, TOR pathway and lipid metabolism was significantly downregulated by increasing dietary CPC level(P < 0.05). In conclusion, based on the quadratic regression analysis of FCR and PER, the optimal replacement levels of fish meal with CPC in crab diet containing 35% fish meal were 32.36% and 35.38%, respectively. It is recommended that Ile, Leu and Thr be

关键词： Eriocheir sinensis Cottonseed protein concentrate Digestibility Amino acid TOR signaling pathway

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关于武昌鱼申遗情况的现状分析

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科教文汇 2012年第27期 205-206页

作者：舒烟雨中国地质大学(武汉)经济管理学院湖北武汉430074

中华老字号是我国工商业发展中孕育的民族品牌,是我国宝贵的精神财富和文化遗产,对工农业发展、繁荣市场、拉动消费、振兴经济、弘扬祖国优秀文化都发挥着重要的作用。而中华老字号中的武昌鱼早在毛主席时期就赢得"武汉第一菜"的美名,... 详细信息

中华老字号是我国工商业发展中孕育的民族品牌,是我国宝贵的精神财富和文化遗产,对工农业发展、繁荣市场、拉动消费、振兴经济、弘扬祖国优秀文化都发挥着重要的作用。而中华老字号中的武昌鱼早在毛主席时期就赢得"武汉第一菜"的美名,并因味道鲜美而闻名天下,然而武昌鱼却在申遗的道路上遭遇尴尬。本文就其申遗情况的现状进行分析,对其将来的发展提供前瞻性的意见。

关键词：武昌鱼文化传承申遗

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ⅢA-ⅡB multicomponent perovskite rare earth ferrites with promising electromagnetic wave absorption properties

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Journal of Rare Earths 2024年第6期42卷 1118-1127,I0005页

作者： Yanyan He Tao Chen yanyu Pan Minzhong Huang Kaixian Wang Liyan Xue Yazhu Li Fengzhi Tan Fan Yang Tongkuan Xu Heng Chen School of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian116034China Xiamen Institute of Rare EarthMaterials Haixi InstitutesChinese Academy of SciencesXiamen36021China Fujian Institute of Research on the Structure of Matter Chinese Academyof SciencesFuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China Xiamen Key-Laboratoryof Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou3410ooChina

Perovskite-type rare-earth ferrites(REFeO_(3))are promising materials for absorbing electromagnetic(EM)wave ***,insufficient dielectric loss and poor impedance matching are key factors that limit the broader implementation of REFeO_(3).Herein,a series of multicomponent perovskite-type ferrites with strong EM wave absorption capabilities was *** the synergistic effect of chemical constitution regulation and entropy regulation,optimization of the dielectric loss and impedance matching is achieved by strengthening the structural defect mechanism,thus further adjusting the EM wave absorption *** with(LaGdSmNdBa)FeO_(3)(HE-1)and(LaGdPrSmNdBa)FeO_(3)(HE-2),(LaGdBa)FeO_(3)(ME-1)and(LaGdSmBa)FeO_(3)(ME-2)exhibit favorable performance,with optimal minimum reflection loss(RL_(min))of-56.35 dB(at 11.12 GHz)and-63.25 dB(at 7.22 GHz)and effective absorption bandwidth(EAB)of 4.46 and 4.72 GHz,*** multicomponent design provides a new strategy for the development of EM wave absorption materials.

关键词： Rare earths Multicomponent design Rare earth ferrites Entropy regulation Electromagnetic wave absorption

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High-entropy rare earth stannate ceramics:Acid corrosion resistant radiative cooling materials with high atmospheric transparency window emissivity and high near-infrared solar reflectivity

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Journal of Advanced Ceramics 2024年第5期13卷 630-640页

作者： Tao Chen Yanyan He yanyu Pan Kaixian Wang Minzhong Huang Liyan Xue Yazhu Li Fan Yang Yanchun Zhou Heng Chen Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117China Xiamen Institute of Rare Earth Materials Haixi InstitutesChinese Academy of SciencesXiamen 361021China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341000China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

In response to the development of the concepts of“carbon neutrality”and“carbon peak”,it is critical to developing materials with high near-infrared(NIR)solar reflectivity and high emissivity in the atmospheric transparency window(ATW;8–13μm)to advance zero energy consumption radiative cooling *** regulate emission and reflection properties,a series of high-entropy rare earth stannate ceramics(HE-RE_(2)Sn_(2)O_(7):(Y_(0.2)La_(0.2)Nd_(0.2)Eu_(0.2)Gd_(0.2))_(2)Sn_(2)O_(7),(Y_(0.2)La_(0.2)Sm_(0.2)Eu_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7),and(Y_(0.2)La_(0.2)Gd_(0.2)Yb_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7))with severe lattice distortion were prepared using a solid phase reaction followed by a pressureless sintering method for the first *** distortion is accomplished by introducing rare earth elements with different cation radii and *** as-synthesized HE-RE_(2)Sn_(2)O_(7)ceramics possess high ATW emissivity(91.38%–95.41%),high NIR solar reflectivity(92.74%–97.62%),low thermal conductivity(1.080–1.619 W·m^(−1)·K^(−1)),and excellent chemical *** the one hand,the lattice distortion intensifies the asymmetry of the structural unit to cause a notable alteration in the electric dipole moment,ultimately enlarging the ATW *** the other hand,by selecting difficult excitation elements,HE-RE_(2)Sn_(2)O_(7),which has a wide band gap(Eg),exhibits high NIR solar ***,the multi-component design can effectively enhance radiative cooling ability of HE-RE_(2)Sn_(2)O_(7)and provide a novel strategy for developing radiative cooling materials.

关键词： radiative cooling materials high-entropy ceramics(HECs) rare earth stannate(RE_(2)Sn_(2)O_(7)) high atmospheric transparency window emissivity high near-infrared(NIR)solar reflectivity

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PRRSV degrades MDA5 via dual autophagy receptors P62 and CCT2 to evade antiviral innate immunity

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Virologica Sinica 2024年第2期39卷 264-276页

作者： Ruiqi Sun yanyu Guo Lilin Zhang Huixia Zhang Boxuan Yin Xiaoyang Li Changyan Li Liu Yang Lei Zhang Zexing Li Jinhai Huang School of Life Sciences Tianjin UniversityTianjin300072China

Porcine reproductive and respiratory syndrome virus(PRRSV)is a major economically devastating pathogen that has evolved various strategies to evade innate *** of antiviral interferon largely promotes PRRSV immunoevasion by utilizing cytoplasmic melanoma differentiation-associated gene 5(MDA5),a receptor that senses viral *** this study,the downregulated transcription and expression levels of porcine MDA5 in PRRSV infection were observed,and the detailed mechanisms were *** found that the interaction between P62 and MDA5 is enhanced due to two factors:the phosphorylation modification of the autophagic receptor P62 by the upregulated kinase CK2αand the K63 ubiquitination of porcine MDA5 catalyzed by the E3 ubiquitinase TRIM21 in PRRSV-infected *** a result of these modifications,the classic P62-mediated autophagy is ***,porcine MDA5 interacts with the chaperonin containing TCP1 subunit 2(CCT2),which is enhanced by PRRSV *** interaction promotes the aggregate formation and autophagic clearance of MDA5-CCT2-nsp3 independently of *** summary,enhanced MDA5 degradation occurs in PRRSV infection via two autophagic pathways:the binding of MDA5 with the autophagy receptor P62 and the aggrephagy receptor CCT2,leading to intense innate immune *** research reveals a novel mechanism of immune evasion in PRRSV infection and provides fundamental insights for the development of new vaccines or therapeutic strategies.

关键词： Porcine reproductive and respiratory syndrome virus(PRRSV) nsp3 Autophagy MDA5

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Glucocorticoid receptor signaling in the brain and its involvement in cognitive function

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Neural Regeneration Research 2025年第9期20卷 2520-2537页

作者： Chonglin Su Taiqi Huang Meiyu Zhang yanyu Zhang Yan Zeng Xingxing Chen Brain Science and Advanced Technology Institute Hubei Province Key Laboratory of Occupational Hazard Identification and ControlSchool of MedicineWuhan University of Science and TechnologyWuhanHubei ProvinceChina

The hypothalamic-pituitary-adrenal axis regulates the secretion of glucoco rticoids in response to environmental *** the brain,a nuclear receptor transcription fa ctor,the glucocorticoid recepto r,is an important component of the hypothalamicpituitary-a d renal axis's negative feedback loop and plays a key role in regulating cognitive equilibrium and *** glucoco rticoid receptor influences cognitive processes,including glutamate neurotransmission,calcium signaling,and the activation of brain-derived neurotrophic factor-mediated pathways,through a combination of genomic and non-genomic *** interactions within the central nervous system can alter the expression and activity of the glucocorticoid receptor,there by affecting the hypothalamic-pituitary-a d renal axis and stress-related cognitive *** appropriate level of glucocorticoid receptor expression can improve cognitive function,while excessive glucocorticoid receptors or long-term exposure to glucoco rticoids may lead to cognitive *** with cognitive impairment-associated diseases,such as Alzheimer's disease,aging,depression,Parkinson's disease,Huntington's disease,stroke,and addiction,often present with dysregulation of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor *** review provides a comprehensive overview of the functions of the glucoco rticoid receptor in the hypothalamic-pituitary-a d renal axis and cognitive *** emphasizes that appropriate glucocorticoid receptor signaling fa cilitates learning and memory,while its dysregulation can lead to cognitive *** provides clues about how glucocorticoid receptor signaling can be targeted to ove rcome cognitive disability-related disorders.

关键词： brain-derived neurotrophic factor calcium signaling glucocorticoid receptor glucocorticoid glutamate transmission hypothalamic-pituitary-adrenal axis long-term potentiation neurocognitive disorders neuroplasticity stress

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