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Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-CoA reductased from developing cotton fibers

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Cell Research 2005年第6期15卷 465-473页

作者： Francois ma PUjOL,Alexander j KAsTANIOTIs,j Kalervo HILTUNEN Biocenter Oulu and Department of Biochemistry University of Oulu P.O. Box 3000 FIN-90014 University of Oulu Finland Biocenter Oulu and Department of Biochemistry University of Oulu P.O. Box 3000 FIN-90014 University of Oulu Finland Biocenter Oulu and Department of Biochemistry University of Oulu P.O. Box 3000 FIN-90014 University of Oulu Finland

Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase ***-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker scKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of scYbr159p.

关键词： very-long-chain fatty acids endoplasmic reticulum fatty acid elongation system 3-ketoacyl-CoA reductase Gossypium hirsutum short-chain alcohol dehydrogenase/reductase protein family.

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Nonlinear free vibrations of porous composite microplates incorporating various microstructural-dependent strain gradient tensors

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Applied mathematics and Mechanics(English Edition) 2022年第6期43卷 825-844页

作者： Duquan ZUO B.sAFAEI s.sAHmaNI Guoling ma Aviation Engineering College Civil Aviation Flight University of ChinaGuanghan 618307Sichuan ProvinceChina Chongqing Engineering Research Center for Advanced Intelligent manufacturing Technology Chongqing Three Gorges UniversityChongqing 404100China Department of Mechanical Engineering Eastern Mediterranean UniversityFamagusta 99628North Cyprus via Mersin 10Turkey school of science and Technology The University of GeorgiaTbilisi 0171Georgia

The main objective of the present numerical analysis is to predict the nonlinear frequency ratios associated with the nonlinear free vibration response of porous composite plates at microscale in the presence of different microstructural gradient *** achieve this end,by taking cubic-type elements into account,isogeometric models of porous composite microplates are obtained with and without a central cutout and relevant to various porosity patterns of distribution along the plate *** established unconventional models have the capability to capture the effects of various unconventional gradient tensors continuity on the basis of a refined shear deformable plate *** the simply supported microsized uniform porous functionally graded material(UPFGM)plate having the oscillation amplitude equal to the plate thickness,it is revealed that the rotation gradient tensor causes to reduce the frequency ratio about 0.73%,the dilatation gradient tensor causes to reduce it about 1.93%,and the deviatoric stretch gradient tensor leads to a decrease of it about 5.19%.On the other hand,for the clamped microsized U-PFGM plate having the oscillation amplitude equal to the plate thickness,these percentages are equal to 0.62%,1.64%,and 4.40%,***,it is found that by changing the boundary conditions from clamped to simply supported,the effect of microsize on the reduction of frequency ratio decreases a bit.

关键词： size dependency isogeometric approach nonlinear dynamics geometric approximation micromechanics

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不同运动模式影响心肌梗死致心力衰竭大鼠骨骼肌重塑的机制

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中国组织工程研究 2025年第2期29卷 221-230页

作者：付常喜何瑞波马刚朱政马文超徐州工程学院体育学院江苏省徐州市221008 中国人民武装警察部队后勤学院卫生勤务系天津市300309

背景:急性心肌梗死可引起心脏重塑和心力衰竭,同时导致骨骼肌病变,影响患者生活质量。运动疗法是心力衰竭患者的重要康复手段,然而最佳运动处方尚未明确。目的:对比不同运动模式(有氧运动、抗阻运动)对急性心肌梗死诱导心力衰竭模型大... 详细信息

背景:急性心肌梗死可引起心脏重塑和心力衰竭,同时导致骨骼肌病变,影响患者生活质量。运动疗法是心力衰竭患者的重要康复手段,然而最佳运动处方尚未明确。目的:对比不同运动模式(有氧运动、抗阻运动)对急性心肌梗死诱导心力衰竭模型大鼠骨骼肌重塑的影响,探讨其可能的作用机制,为优化运动康复方案提供依据。方法:48只sD大鼠随机分为假手术组、心肌梗死组、有氧运动组和抗阻运动组。利用冠状动脉结扎术进行心力衰竭模型制作,3个月后有氧运动组和抗阻运动组进行12周相应运动模式干预,假手术组和心肌梗死组于鼠笼内安静饲养。实验后,利用递增负荷跑台运动实验和爬梯实验分别测定大鼠最高跑速和最大负重,超声心动图评估心脏结构与功能;分离出心脏,分别行苏木精-伊红染色和天狼星红染色观察心脏重塑情况;分离出腓肠肌,行ATP酶染色观察肌纤维类型和细胞横截面积改变,二氢乙锭法评估活性氧水平,酶联免疫吸附法测定丙二醛含量以及抗氧化酶活性,免疫印迹法测定泛素-蛋白酶体系统蛋白表达量,双重免疫荧光染色检测活化的卫星细胞数(Pax7^(+)/MyoD^(+))。结果与结论:①运动能力:与假手术组比较,心肌梗死组最高跑速和最大负重下降(P0.05)。③骨骼肌重塑:与假手术组比较,心肌梗死组腓肠肌质量、腓肠肌质量指数、细胞横截面积、超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性、活化的卫星细胞数量下降(PmaFbx蛋白表达量上调(PmaFbx蛋白表达量降低(P<0.05);与有氧运动组比较,抗阻运动组腓肠肌质量、腓肠肌质量指数、细胞横截面积、活性氧水平、丙二醛含量、活化的卫星细胞数量升高(P<0.05),超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性下调(P<0.05)。结果表明:有氧运动和抗阻运动均可提升心力衰竭大鼠的运动能力,其机制与减轻氧化应激、抑制泛素-蛋白酶体系统活性以及激活卫星细胞进而改善骨骼肌重塑有关。有氧运动对于改善骨骼肌氧化应激作用更佳,而抗阻运动促进骨骼肌再生方面效果更为显著。

关键词：心肌梗死心力衰竭运动心脏骨骼肌重塑

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Waste to energy(WTE)in China:from latecomer to front runner

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Waste Disposal and sustainable Energy 2021年第4期3卷 267-274页

作者： Nickolas j.Themelis Wenchao ma Earth Engineering Center(EEC) Columbia University and Chair of Global WtERT Council(GWC)New YorkNYUSA Faculty of Environmental science and Engineering Tianjin UniversityTianjin 300072China

This paper discusses the 2000-2018 evolution of energy and metals recovery from urban wastes in the European Union and *** a result of the zero-landfilling directive,in twenty years the European Union tripled its recycling rate(11%-30%)and its composting rate(6%-17%),doubled its WTE rate(14%-28%)and more than halved its landfilling(64%-25%).At the beginning of this century,the rapidly growing cities of China were literally surrounded by ***,the national government instituted policies,such as a credit of Us$30 per MWh of WTE(waste to energy)electricity that resulted in the construction,by 2020,of 510 WTE plants with an annual WTE capacity of 193 million *** comparison,the European Union(EU)WTE capacity is 96 million tons and the UsA has remained static at about 27 million tons,i.e.,10%of its post-recycling MsW(municipal solid waste),with the other 90%being *** the first decade of this century,two WTE technologies,moving grate and circulating fluid bed were developed in China at about the same ***,since 2010,the moving grate technology has become dominant and the WTE plants are built functionally and esthetically comparable to and ***.

关键词： Waste to energy WTE capacity Moving grate Circulating fluid bed sustainable waste management

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sleep as a window to understand and regulate Alzheimer's disease:emerging roles of thalamic reticular nucleus

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Neural Regeneration Research 2025年第6期20卷 1711-1712页

作者： Haoqi sun shiqian shen Robert j.Thomas M.Brandon Westover Can Zhang Department of Neurology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Center for Translational Pain Research Department of AnesthesiaCritical Care and Pain MedicineMassachusetis General HospitalHarvard Medical SchoolBostonMAUSA Division of Pulmonary Critical Care and Sleep MedicineDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Genetics and Aging Research Unit McCance Center for Brain HealthMass General Institute for Neurodegenerative DiseaseDepartment of NeurologyMassachusetts General HospitalHarvard Medical SchoolBostonMAUSA

Introduction:Alzheimer 's disease(AD) is a common neurodegenerative disorder and the primary cause of dementia. Considerable evidence supports the “amyloid hypothesis,” stating that the pathogenesis of AD is primarily caused by the deposition of amyloid-β(Aβ), which drives tau phosphorylation, neuroinflammation, and neurodegeneration in the brain. The amyloid hypothesis is strengthened by the significant and moderate benefit of lecanemab, a humanized antibody through an anti-amyloid mechanism,showing slowed clinical decline(van Dyck et al.,2023). The recent positive results of anti-amyloid trials have brought back focus on the amyloid hypothesis through biochemical, genetic, and pharmacological approaches(Zhang, 2023).

关键词： Alzheimer inflammation hypothesis

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Touristic urbanization and greening of coastal dune fields:A long-term assessment of a temperate sandy barrier of Argentina

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journal of Geographical sciences 2025年第1期35卷 206-230页

作者： GARZO Pedro Andrés DADON josé Roberto IsLA Federico Ignacio Instituto de Investigaciones marinas y Costeras (IIMyC-CONICET/UNMDP) Instituto de Geología de Costas y del Cuaternario Dr.Enrique j.schnack (IGCC-CIC/UNMDP) Universidad de Buenos Aires Facultad de Arquitectura Dise?o y Urbanismo Centro de Investigaciones Gestión de Espacios Costeros (GEC-FADU/UBA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Dune barrier systems represent highly sought-after coastal landscapes for tourism and urban development around the world. However, a century ago, they were considered hazardous environments due to their great dynamic nature. As a result, stabilization practices were considered necessary. The systematic introduction of fast-growing exotic trees helped stabilize the sand, making it easier for tourism urbanization to take place, but also leading to erosion processes. This paper aims to assess long-term changes in vegetation cover over a large temperate barrier in Argentina. This complex region includes urban resorts, afforestation zones, and protected areas. A GIs-based geospatial analysis was conducted using a large satellite database(> 350 images), and the future evolution of the vegetation was modeled. The results revealed two primary spatiotemporal patterns associated with a gradual expansion of vegetation cover, accompanied by a concurrent reduction in sandy areas. In 1986, the dune area comprised 75% more surface than vegetation, whereas in 2021, it represented 60% less than vegetation. Furthermore, the 2050 scenario suggests a potential 40% reduction of dunes in certain areas. It is necessary to enhance management actions aimed at maintaining dune mobility and ensuring local and regional sediment balance. Long-term management strategies must focus on restoring native plant communities and controlling invasive species, and avoiding new dune fixation initiatives based on the introduction of exotic species.

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Mixing and Recirculation Characteristics of A Double Concentric Burner with Bluff-Body

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journal of Thermal science 1993年第4期2卷 294-303页

作者： H.K.ma C.H.Chiou j.s.Harn Department of Mechanical Engineering National Taiwan University

The concentric bluff-body jet burner is widely used in industrial combustion *** kind of burner often generates a considerably complex recirculation zone behind the bluff *** a result, the fuel often remains in the recirculation zone,achieving stability of *** study investigates, by means of experiments,the variations of the aerodynamics as the fluid is injected into a combustion chamber through a double concentric burner with a *** observation and measurement of the aerodynamics in our experiment are conducted under a cold *** controlled parameters in our experiment are:variations in the blockage ratio of the center bluff body,the cone angle of the bluff body,and the velocity ratio(U_s/U_p)of the secondary jet and primary jet;the injection of helium bubbles into the primary and secondary jets to observe the recirculation zone behind the bluff body;using Tufts for observing the characteristics of corner recirculation zone in a combustion chamber,measuring the average velocity of each point within the aerodynamics by the 5-hole pitot tube;measuring the distribution of static pressure of the combustion chamber walls with a static pressure tap.

关键词： concentric jet burner with bluff body internal aerodynamics of the burner parameters affecting the flow fields in the burner

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Timoshenko beam model for chiral materials

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Acta Mechanica sinica 2018年第3期34卷 549-560页

作者： T.Y.ma Y.N.Wang L.Yuan j.s.Wang Q.H.Qin Department of Mechanics Tianjin University school of Engineering Deakin University Research school of Engineering Australian National University

Natural and artificial chiral materials such as deoxyribonucleic acid （DNA）, chromatin fibers, flagellar filaments, chiral nanotubes, and chiral lattice materials widely exist. Due to the chirality of intricately helical or twisted microstructures, such materials hold great promise for use in diverse applications in smart sensors and actuators, force probes in biomedical engineering, structural elements for absorption of microwaves and elastic waves, etc. In this paper, a Timoshenko beam model for chiral materials is developed based on noncentrosymmetric micropolar elasticity theory. The governing equations and boundary conditions for a chiral beam problem are derived using the variational method and Hamilton＇s principle. The static bending and free vibration problem of a chiral beam are investigated using the proposed model. It is found that chirality can significantly affect the mechanical behavior of beams, making materials more flexible compared with nonchiral counterparts, inducing coupled twisting deformation, relatively larger deflection, and lower natural frequency. This study is helpful not only for understanding the mechanical behavior of chiral materials such as DNA and chromatin fibers and characterizing their mechanical properties, but also for the design of hierarchically structured chiral materials.

关键词： Timoshenko beam model Chiral material Chirality Deflection Microrotation

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Mechanical Properties of a Low-thermal-expansion Aluminum/silicon Composite Produced by Powder Metallurgy

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journal of materials science & Technology 2014年第4期30卷 417-422页

作者： Y.Q.Liu s.H.Wei j.Z.Fan Z.L.ma T.Zuo National Engineering & Technology Research Center for Nonferrous Metal matrix Composites Beijing General Research Institute for Nonferrous Metals

AI matrix composite containing high volume fraction silicon has been promising candidate for lightweight and low-thermal-expansion components. Whereas, optimization of its mechanical properties still is an open challenge. In this article, a flexile powder metallurgy processing was used to produce a fully dense AI-4.0Cu （wt%） alloy composite reinforced with 65 vol.% si particles. In this composite, si particles were homogenously distributed, and the particle size was refined to the range of 3-15 μm. Tensile and flexural strength of the composite were 282 and 455 MPa, respectively, about 100% and 50% higher than the best properties reported in literature. The measured fracture toughness of the composite was 4.90 MPa m1/2. The improved strength of 65%si/AI was attributed to the optimized particle characteristics and matrix properties. This investigation is expected to provide a primary understanding of the mechanical behaviors of si/AI composites, and also promote the structural applications of this low-thermal-expansion material.

关键词： Aluminum matrix composite Powder metallurgy Mechanical properties Coefficient of thermal expansion Fracture

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CHARACTERIZATION OF si_(1-x-y)Ge_xC_y FILMs GROWN BY ION IMPLANTATION AND sUBsEQUENT sOLID PHAsE EPITAXY

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Acta Metallurgica sinica(English Letters) 2002年第1期15卷 49-52页

作者： X.Q. Liu Y.Y. Wang W.j. Cheng j. Zhang s.Y. ma Dept. of Phys. Lanzhou Univ. Lanzhou 730000 China

si1-x-yGexCy ternary alloy films were grown on monocrystalline silicon substrates by C+ ion implantation and subsequent solid phase epitaxy (sPE). Two-step annealing technique was employed in the sPE. The structure and electrical properties of the alloy films were determined using Fourier transform infrared spectroscopy and van der Pauw Hall measurements, respectively. With the optimization of two-step annealing technique for the implanted si1-x-yGexCy layers, a certain amount of C atoms occupied substitutional sites and no siC was formed.

关键词： si1-x-yGexCu film ion implantation sPE

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