检索结果-南通市图书馆

Skeletal phenotypes and molecular mechanisms in aging mice

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2024年第4期45卷 724-746页

作者： Qiao Guan Yuan Zhang zhi-Kun Wang Xiao-Hua Liu Jun Zou ling-Li Zhang School of Exercise and Health Shanghai University of SportShanghai 200438China College of Athletic Performance Shanghai University of SportShanghai 200438China

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health *** on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial ***,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation *** this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial ***,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

关键词： Aging Premature aging Mice Bone Gene knockout

In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第3期43卷 478-488页

作者： yi Cui Hanjie Wen Zhengbing Zhou Kunyue ling Lin Xu Shirong Liu Fei Xu School of Earth Sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences and Resources Chang’an UniversityXi’an 710054China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for *** McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,***,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous ***,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic *** results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic *** the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay *** to the octahedral sites of Mg-smectite bounded in Li,it is referred to be *** interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt *** conclusion can be supported by the coexistence of spherulitic calcite and ***,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.

关键词： McDermitt caldera Lithium occurrence Tuffaceous sediments Mineralogy Hectorite neoformation

Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-ling Zheng Shao-Xiang Li Jia-Le Ma Qing-Yan Xu Hai-Dong Zhao zhi-Qiang Han Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly *** samples were solution treated at 535℃ for 15 min to 12 *** microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy(OM),scanning electron microscopy(SEM) and oscillography impact *** results show that the addition of Sr and La refined the eutectic Si particles significantly from~ 2.05 μm(modified with Sr alone) to~ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 *** alloy exhibits excellent impact toughness up to 75 J·cm^(-2),which is much higher than the maximum impact toughness of the alloys modified by Sr alone(~ 46 J·cm^(-2)).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation *** dispersoid-free zones(DFZs)near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent *** ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism

Cutting performance of saw blades with microtextured rougher and finisher sawteeth

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 317-334页

作者： Yang Lu Jian-Xin Deng zhi-Hui Zhang Jia-Xing Wu Ran Wang yi-Chen Bao Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE School of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China

The problems of severe sawtooth wear,harsh sawing noise,and low surface quality during the processing of circular saw blades need to be *** improve the cutting performance of TiC-based cermet saw blades,microtextures parallel to the cutting edge were fabricated on rough and fine sawteeth by laser *** cutting tests were performed on a sawing platform under lubricated *** of the sawing arc length and working sawtooth cutting force variations were developed for sawing steel pipes,and the accuracy of the sawing force model was verified *** results indicate that the variations in the sawing force are proportional to the sawing arc *** circular saw blades with microtextures that did not penetrate the sawtooth rake face exhibited the lowest cutting force,sawing noise,and highest machined surface ***,the worn-out distance of the rougher and finisher sawteeth was reduced by approximately 7.4%and 44.1%,respectively,compared with conventional circular saw *** main failure modes of sawteeth were tip wear,rake face adhesion,and oxidative *** addition,the mechanism by which the textures improve the cutting and wear properties of TiC-based circular saw blades was *** study provided a significant concept for enhancing the cutting performance of circular saw blades and improving the machined surface quality.

关键词： Circular saw blades Micro textures Cutting performance Wear performance

Does the Hartman effect exist in triangular barriers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 214-230页

作者：李青玲郑爽肖智 Department of Mathematics and Physics North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000Chin

We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and height for a pair of mirror-symmetric(MS)exact triangular barriers(ETBs)are quite different,as the two ETBs have quite distinct scattering *** comparison,the dependence of the transmitted phase or Larmor times is exactly the same,since the transmitted amplitudes are the same for a pair of MS *** further study the Hartman effect by defining the phase and Larmor velocities associated with the phase and Larmor *** find no barrier width saturation effect for the transmitted and reflected *** is indicated by the fact that all the velocities approach finite constants that are much smaller than the speed of light in vacuum for TBs with positive-slope impact *** for ETBs with vertical left edges,the naive velocities seem to also indicate the absence of the Hartman *** are quite distinct from rectangular barriers and may shed new light on the clarification of the tunneling time issues.

关键词： triangular barrier Hartman effect

Establishment of a selectable marker recycling system for iterative gene editing in Fusarium fujikuroi

在线全文

学校读者我要写书评

暂无评论

Synthetic and Systems Biotechnology 2024年第1期9卷 159-164页

作者： Tian-Qiong Shi Cai-ling Yang Dong-Xun Li Yue-Tong Wang zhi-Kui Nie Jiangxi New Reyphon Biochemical Co. LtdSalt&Chemical IndustryXinganJiangxi331399People’s Republic of China School of Food Science and Pharmaceutical Engineering Nanjing Normal University2 Xuelin RoadQixia DistrictNanjing210023People’s Republic of China

Gibberellic acid(GA3)is a vital plant growth hormone widely used in ***,GA3 production relies on liquid fermentation by the filamentous fungus Fusarium ***,the lack of an effective selection marker recycling system hampers the application of metabolic engineering technology in ***,as multiple-gene editing and positive-strain screening still rely on a limited number of *** this study,we developed a strategy using pyr4-blaster and CRISPR/Cas9 tools for recycling orotidine-5'-phosphate decarboxylase(Pyr4)selection *** demonstrated the effectiveness of this method for iterative gene integration and large gene-cluster *** also successfully improved GA3 titers by overexpressing geranylgeranyl pyrophosphate synthase and truncated 3-hydroxy-3-methyl glutaryl coenzyme A reductase,which rewired the GA3 biosynthesis *** results highlight the efficiency of our established system in recycling selection markers during iterative gene editing ***,the selection marker recycling system lays the foundation for further research on metabolic engineering for GA3 industrial production.

关键词： F.fujikuroi Gibberellic acid Plant growth hormone Selection marker recycling system CRISPR/Cas9 pyr4-blaster

Cone-beam computed tomography noise reduction method based on U-Net with convolutional block attention module in proton therapy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 89-100页

作者： Xing-Yue Ruan Xiu-Fang Li Meng-Ya Guo Mei Chen Ming Lv Rui Li zhi-ling Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201800China University of Chinese Academy of Sciences Beijing100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China Department of Radiation Oncology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China Shanghai Key Laboratory of Proton therapy Shanghai201801China

Cone-beam computed tomography(CBCT) is mostly used for position verification during the treatment process. However,severe image artifacts in CBCT hinder its direct use in dose calculation and adaptive radiation therapy re-planning for proton therapy. In this study, an improved U-Net neural network named CBAM-U-Net was proposed for CBCT noise reduction in proton therapy, which is a CBCT denoised U-Net network with convolutional block attention modules. The datasets contained 20 groups of head and neck images. The CT images were registered to CBCT images as ground truth. The original CBCT denoised U-Net network, sCTU-Net, was trained for model performance comparison. The synthetic CT(SCT) images generated by CBAM-U-Net and the original sCTU-Net are called CBAM-SCT and U-Net-SCT images, respectively. The HU accuracies of the CT, CBCT, and SCT images were compared using four metrics: mean absolute error(MAE), root mean square error(RMSE), peak signal-to-noise ratio(PSNR), and structure similarity index measure(SSIM). The mean values of the MAE, RMSE, PSNR, and SSIM of CBAM-SCT images were 23.80 HU, 64.63 HU, 52.27 dB, and 0.9919, respectively,which were superior to those of the U-Net-SCT images. To evaluate dosimetric accuracy, the range accuracy was compared for a single-energy proton beam. The γ-index pass rates of a 4 cm × 4 cm scanned field and simple plan were calculated to compare the effects of the noise reduction capabilities of the original U-Net and CBAM-U-Net on the dose calculation results. CBAM-U-Net reduced noise more effectively than sCTU-Net, particularly in high-density tissues. We proposed a CBAM-U-Net model for CBCT noise reduction in proton therapy. Owing to the excellent noise reduction capabilities of CBAM-U-Net, the proposed model provided relatively explicit information regarding patient tissues. Moreover, it maybe be used in dose calculation and adaptive treatment planning in the future.

关键词： Proton therapy Cone-beam CT CBAM-U-Net γ-index

An Efficient Optimization Design Framework for Low-Resistance Shape of Bionic Amphibious Robot

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第1期38卷 117-128页

作者： ZHANG Dai-yu ZHANG Man-yu WANG zhi-dong ZHENG Wen-sheng ling Hong-jie HU Jun-ming School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

To realize the low-resistance shape optimization design of amphibious robots,an efficient optimization design framework is proposed to improve the geometric deformation flexibility and optimization *** the proposed framework,the free-form deformation parametric model of the flat slender body is established and an analytical calculation method for the height constraints is *** method is introduced to carry out the high-precision resistance calculation and a constrained Kriging-based optimization method is built to improve the optimization efficiency by circularly infilling the new sample points which satisfying the ***,the shape of an amphibious robot example is optimized to get the low-resistance shape and the results demonstrate that the presented optimization design framework has the advantages of simplicity,flexibility and high efficiency.

关键词： amphibious robot optimization method free-form deformation CFD-based hydrodynamic calculation

Influence of heat treatment on microstructure,mechanical and corrosion behavior of WE43 alloy fabricated by laser-beam powder bed fusion

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第1期6卷 258-275页

作者： Chenrong ling Qiang Li Zhe Zhang Youwen Yang Wenhao Zhou Wenlong Chen zhi Dong Chunrong Pan Cijun Shuai College of Mechanical and Electrical Engineering Jiangxi University of Science and TechnologyGanzhou 341000People’s Republic of China School of Mechanical and Electronic Engineering Suzhou UniversitySuzhou 234000People’s Republic of China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016People’s Republic of China Department of Orthopedics First Afffliated Hospital of Gannan Medical CollegeGanzhou 341000People’s Republic of China School of Mechanical and Automotive Engineering South China university of technologyGuangzhou 510641People’s Republic of China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083People’s Republic of China Double Medical Technology Inc. Xiamen 361026People’s Republic of China

Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical ***-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated ***,the as-built part usually exhibits undesirable microstructure and unsatisfactory *** this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat *** a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich *** heat treatment,fine and nano-scaled Mg24Y5particles were ***,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the *** a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation ***,the degradation rate of WE43 parts was decreased by an order of ***,in-vitro cell experiments proved their favorable biocompatibility.

关键词： laser-beam powder bed fusion WE43 alloys heat treatment mechanical performance biodegradation behavior