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Autophagic deficiency is related to steroidogenic decline in aged rat Leydig cells

Asian Journal of Andrology 2011年第6期13卷 881-888页

作者： Wei-Ren Li Liang Chen Zhi-Jie Chang Hua Xin Tao Liu yan-Quan Zhang Guang-Yong Li Feng Zhou yan-qing gong Zhe-Zhu Gao Zhong-Cheng Xin Andrology Center Peking University First Hospital Peking University Beijing 100034 China Department of Urology China Meitan General Hospital Beijing 100028 China Department of Biological Sciences and Biotechnology School of Medicine Tsinghua University Beijing 100084 China

Late-onset hypogonadism （LOH） is closely related to secondary androgen deficiency in aged males, but the mechanism remains unclear. In this study, we found that reduced testosterone production in aged rat Leydig cells is associated with decreased autophagic activity. Primary rat Leydig cells and the TM3 mouse Leydig cell line were used to study the effect of autophagic deficiency on Leydig cell testosterone production. In Leydig cells from young and aged rats, treatment with wortmannin, an autophagy inhibitor, inhibited luteinising hormone （LH）-stimulated steroidogenic acute regulatory （STAR） protein expression and decreased testosterone production. In contrast, treatment with rapamycin, an autophagy activator, enhanced LH-stimulated steroidogenesis in Leydig cells from aged, but not young, rats. Intracellular reactive oxygen species （ROS） levels were increased in both young and aged Leydig cells treated with wortmannin but decreased only in aged Leydig cells treated with rapamycin. Furthermore, an increased level of ROS, induced by H2O2, resulted in LH-stimulated steroidogenic inhibition. Finally, knockdown of Beclin 1 decreased LH-stimulated StAR expression and testosterone production in TM3 mouse Leydig cells, which were associated with increased intracellular ROS level. These results suggested that autophagic deficiency is related to steroidogenic decline in aged rat Leydig cells, which might be influenced by intracellular ROS levels.

关键词： ageing autophagy late onset hypogonadism Leydig cell reactive oxygen species testosterone

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Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China Earth Sciences 2024年第5期67卷 1436-1458页

作者： qing gong Ming-Xing LING Wang ZHENG State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)***,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic *** stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic *** date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the ***,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of *** a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

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Anomalous thermal expansion and enhanced magnetocaloric effect in<001>-textured Mn_(x)Fe_(5-x)Si_(3) alloys

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Rare Metals 2024年第5期43卷 2263-2274页

作者： Yong gong Xue-Fei Miao Tapas Samanta Chris Taake Jun Liu Feng-Jiao Qian yan-yan Shao Yu-Jing Zhang qing-Yong Ren Luana Caron Feng Xu MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Department of Physics Bielefeld University33501BielefeldGermany College of Physics Nanjing University of Aeronautics and AstronauticsNanjing210016China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Spallation Neutron Source Science Center Dongguan523803China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology Dongguan523803China Department of Physics Bielefeld University33501BielefeldGermany Helmholtz-Zentrum Berlin für Materialien und Energie12489BerlinGermany

The development of zero and negative therma expansion(i.e.,ZTE and NTE)materials is of crucial importance to the control of undesirable thermal expansion for high-precision *** the present work,ZTE and NTE were obtained in directionally-solidified Mn_(x)Fe_(5-x)Si_(3)alloys with a strongtexture,in striking contrast to positive thermal expansion in their isotropic counterparts Magnetometry and in-situ X-ray diffraction(XRD)measurements were performed to uncover the origin of the anomalous thermal *** measurements indicate a strong easy-plane magnetocrystalline anisotropy in the textured samples,where the magnetic moments are aligned within the ab plane of the hexagonal structure Temperature-dependent XRD on the x=1 sample reveals a ZTE character in the ab plane that is coupled to a ferromagnetic *** a result,the macroscopic ZTE(~0.22×10^(-6)K^(-1))in the x=1 sample can be attributed to the microscopic magneto volume effect within the ab plane,which is realized by the introduction of the-textured ***,the competition between antiferromagnetic and ferromagnetic exchange coupling leads to NTE in textured x=1.5 and 2 ***,textured x=1 sample displays enhanced magnetocaloric properties as compared to the conventional counterparts with randomly-oriented *** this work demonstrates a new strategy toward the exploration of anomalous thermal expansion properties as well as the enhancement of magnetocaloric properties for materials with a strong magnetocrystalline anisotropy.

关键词： MnFeySis Magnetocaloric effect Magnetic phase transition Negative thermal expansion

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Recent geomagnetic storms observed by Macao Science Satellite-1

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Earth and Planetary Physics 2024年第4期8卷 565-569页

作者： qing yan HongBo Yao Macao Institute of Space Technology and Application Macao University of Science and TechnologyMacao 999078China

Geomagnetic storms are rapid disturbances of the Earth’s *** are related to many geophysical phenomena and have large influences on human *** and studying geomagnetic storms is thus of great significance to both scientific research and geomagnetic hazards *** Macao Science Satellite-1(MSS-1)project includes two high-precision Chinese geomagnetic satellites successfully launched on May 21,*** main purpose of MSS-1 is to accurately measure the Earth’s magnetic ***,we analyze early MSS-1 geomagnetic field measurements and report observations of two recent geomagnetic storms that occurred on March 24,2024 and May 11,*** also calculate the related geoelectric fields as an initial step towards a quantitative assessment of geomagnetic hazards.

关键词： Macao Science Satellite-1 geomagnetic storms satellite magnetics electromagnetic induction geoelectric fields

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Lightweight innovation ADIs help development of renewable energy and new technology industries in China

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China Foundry 2024年第5期21卷 507-515页

作者： Qi-dong yan Xu-dong gong Wen-bang gong Jin-cheng Liu ADI Committee of China Foundry Association Beijing 100000China Yuzhou Henglilai New Materials Co. Ltd.Xuchang 452570HenanChina Kunshan Changjian Foundry Industry Co.Ltd. Kunshan 215311JiangsuChina School of Mechanical Engineering and Automation Wuhan Textile UniversityWuhan 430200China WFO Ferrous Metals Commission Shenyang 110022China

The world is undergoing profound changes in energy and *** are vigorously developing new sustainable energy sources and *** energy sources encompass various technologies such as wind turbines,solar energy,nuclear energy,and ***,emerging technology fields include new energy vehicles,robots,and artificial intelligence devices,among *** renewable energy industries and implementation of new technologies necessitate the development and adoption of new equipment and *** ductile iron(ADI)is renowned for its unique microstructure and superior *** utilizing ADI,lightweight and innovative castings can be designed to not only reduce weight but also save energy and decrease *** importantly,these castings enhance the efficiency and reliability of new energy equipment and emerging technology *** paper describes the development,applications,and future prospects of lightweight and innovative ADI castings within sectors such as solar photovoltaic(PV),wind power generation,industry robots,and trucks in China.

关键词： lightweight ADI renewable energy emission reduction

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Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter

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Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin yan gong Bin Yue Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for High Energy Physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope(JWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the JWST *** this work,we study WDM as a possible solution to reconcile the JWST stellar mass density of high-z massive galaxies and reionization *** find that,the JWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the JWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe

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Numerical simulation on directional solidification and heat treatment processes of turbine blades

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China Foundry 2024年第5期21卷 476-490页

作者： Ye-yuan Hu Ju-huai Ma qing-yan Xu School of Materials Science and Engineering Tsinghua UniversityKey Laboratory for Advanced Materials Processing TechnologyMinistry of EducationBeijing 100084China

Study on turbine blades is crucial due to their critical role in ensuring the efficient and reliable operation of aircraft ***-based single crystal superalloys are extensively used in the hot manufacturing of turbine blades due to their exceptional high-temperature mechanical *** hot manufacturing of single crystal blades involves directional solidification and heat *** manufacturing of these blades is time-consuming,capital-intensive,and often insufficient to meet industrial *** simulation techniques have gained widespread acceptance in blade manufacturing research due to their low energy consumption,high efficiency,and rapid turnaround *** article introduces the modeling and simulation of hot manufacturing in single crystal *** discussion outlines the prevalent mathematical models employed in numerical simulations related to blade hot *** encapsulates the advancements in research concerning macro to micro-level numerical simulation techniques for directional solidification and heat treatment ***,potential future trajectories for the numerical simulation of single crystal blade hot manufacturing are also discussed.

关键词： single crystal blades Ni-based superalloy directional solidification heat treatment numerical simulation

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Sponge as Scaffolds in Bone and Cartilage Tissue Engineering

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Chemical Research in Chinese Universities 2024年第5期40卷 786-797页

作者： LUO Lei gong Yining yan Liang BU Yazhong yan’an University Yan’an716000P.R.China Department of Spine Surgery Honghui HospitalXi’an Jiaotong UniversityXi’an710054P.R.China Institute of Medical Engineering Department of BiophysicsSchool of Basic Medical SciencesHealth Science CenterXi’an Jiaotong UniversityXi’an710061P.R.China

In recent years,tissue scaffolds have emerged as a new therapeutic method for bone and cartilage regeneration,with sponge scaffolds gaining increasing *** scaffolds possess several favorable characteristics,including appropriate biodegradability,excellent biocompatibility,good processability,powerful osteogenic ability,a unique porous structure,and adjustable pore size and *** attributes make sponge scaffolds a promising option for bone and cartilage ***,to date,there is a lack of comprehensive reviews summarizing the use of sponge scaffolds in this *** this review,our objective is to provide a comprehensive overview of the research progress and development trends of sponge ***,we introduce the various materials used for sponge ***,we summarize the different preparation methods employed for creating sponge ***,we discuss the functional additives that can be incorporated into the ***,we present some special structures that can be achieved in sponge *** aim is for this review to offer valuable insights and serve as a comprehensive resource for the design of sponge scaffolds in cartilage and bone regeneration.

关键词： Bone Sponge Scaffold Tissue regeneration

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Cut-off value of glycated hemoglobin A1c for detecting diabetic retinopathy in the Chinese population

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World Journal of Diabetes 2024年第7期15卷 1531-1536页

作者： yan Wen qing Wang Department of Endocrinology China-Japan Union Hospital of Jilin UniversityChangchun 130033Jilin ProvinceChina

BACKGROUND Glycated hemoglobin A1c(HbA1c)is considered the most suitable for diabetes mellitus diagnosis due to its accuracy and ***,the effect of HbA1c on diabetic retinopathy(DR)in the Han and Korean populations in Jilin,China,remains *** To determine the best cut-off of HbA1c for diagnosing DR among the *** This cross-sectional study included 1933 participants from the yanbian area of Jilin Province,*** investigators employed a questionnaire-based survey,physical examination,laboratory tests,and fundus photography for the *** best cut-off value for HbA1c was established via the receiver operating characteristic *** factors associated with HbA1c-associated risk factors were determined via linear *** The analysis included 887 eligible Chinese Han and Korean participants,591 of whom were assigned randomly to the training set and 296 to the validation *** prevalence of DR was 3.27% in the total ***1c of 6.2% was the best cut-off value in the training set,while it was 5.9% in the validation *** both Chinese Han and Korean populations,an HbA1c level of 6.2% was the best cut-off *** optimal cut-off values of fasting blood glucose(FBG)≥7 mmol/L and<7 mmol/L were 8.1% and 6.2% respectively in Han populations,while those in Korean populations were 6.9%and 5.3%,***,body mass index,and FBG were determined as the risk factors impacting HbA1c *** HbA1c may serve as a useful diagnostic indicator for *** HbA1c level of 6.2% may be an appropriate cut-off value for DR detection in the Chinese population.

关键词： Diabetic retinopathy Glycated hemoglobin A1c Cut-off value Age Body mass index Fasting blood glucose

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Model Parameters Identification and Backstepping Control of Lower Limb Exoskeleton Based on Enhanced Whale Algorithm

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 100-114页

作者： yan Shi Jiange Kou Zhenlei Chen Yixuan Wang qing Guo School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China

Exoskeletons generally require accurate dynamic models to design the model-based controller conveniently under the human-robot interaction ***,due to unknown model parameters such as the mass,moment of inertia and mechanical size,the dynamic model of exoskeletons is difficult to ***,an enhanced whale optimization algorithm(EWOA)is proposed to identify the exoskeleton model ***,the periodic excitation trajectories are designed by finite Fourier series to input the desired position demand of exoskeletons with mechanical physical *** a backstepping controller based on the identified model is adopted to improve the human-robot wearable comfortable performance under cooperative ***,the proposed Model parameters identification and control are verified by a two-DOF exoskeletons *** knee joint motion achieves a steady-state response after 0.5 ***,the position error of hip joint response is less than 0.03 rad after 0.9 *** addition,the steady-state human-robot interaction torque of the two joints is constrained within 15 N·*** research proposes a whale optimization algorithm to optimize the excitation trajectory and identify model ***,an enhanced mutation strategy is adopted to avoid whale evolution’s unsatisfactory local optimal value.

关键词： Parameter identification Enhanced whale optimization algorithm(EWOA) Backstepping Human-robot interaction Lower limb exoskeleton

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