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Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable Mg-3Y alloy prepared by selective laser melting and spark plasma sintering

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Journal of Magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： P.Minárik M.Zemková S.Šašek J.Dittrich M.Knapek F.Lukáˇc D.Koutný J.Jaroš R.král Faculty of Mathematics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of Plasma Physics of the Czech Academy of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of Machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy Mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SPS)and selective laser melting(SLM).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLM material and unmeasurably low porosity in the SPS *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 MPa in tension and compression and relatively good deformability of∼9%and∼21%for the SLM and SPS materials,*** corrosion resistance of the SPS material in 0.1 M NaCl solution was superior to the SLM one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLM *** the other hand,one of the primary outcomes of this study is that the SPS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： Magnesium Yttrium Powder metallurgy Microstructure Mechanical strength Corrosion resistance

Diameter distributions in Pinus sylvestris ***:evaluating modelling approaches including a machine learning technique

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林业研究:英文版 2023年第6期34卷 1829-1842页

作者： Şükrü Teoman Güner Maria J.Diamantopoulou Ramazan Özçelik Department of Forestry Ulus Vocational SchoolBartın University74600 UlusBartınTurkey Faculty of Agriculture Forestry and Natural EnvironmentSchool of Forestry and Natural EnvironmentAristotle University of Thessaloniki54124 ThessalonikiGreece Faculty of Forestry Isparta University of Applied ScienceEast Campus32260 IspartaTurkey

The diameter distribution of trees in a stand provides the basis for determining the stand’s ecological and economic value,its structure and stability and appropriate management *** pine(Pinus sylvestris L.)is one of the most common and important conifers in Turkey,so a well-planned management schedule is *** distribution models to accurately describe the stand structure help improve management strategies,but developing reliable models requires a deep understanding of the growth,output and constraints of the *** most important information derived by diameter distribution models is primary data on horizontal stand structure for each diameter class of trees:basal area and volume per unit *** predictions are required to estimate the range of products and predicted volume and yield from a forest ***,to construct an accurate,reliable diameter distribution model for natural Scots pine stands in the Türkmen Mountain region,we used Johnson’s SBdistribution to represent the empirical diameter distributions of the stands using ground-based measurements from 55 sample plots that included1219 trees in natural distribution zones of the *** an alternative,nonparametric approach,which does not require any predefined function,an artificial intelligence model was constructed based on support vector machine *** error index was calculated to evaluate the ***,both Johnson’s SB probability density function with a three-parameter recovery approach and the support vector regression methodology provided reliable estimates of the diameter distribution of these stands.

关键词： Diameter distribution Johnson’s S_(B) Support vector regression Scots pine Türkmen mountains

Inhibition of Ehrlich ascites carcinoma growth by melatonin:Studies with micro-CT

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Oncology Research 2024年第1期32卷 175-185页

作者： SEHER YILMAZ ZÜLEYHA DOĞANYIĞIT MERT OCAK EVRIM SUNA ARIKAN SÖYLEMEZ ASLI OKAN OFLAMAZ SÜMEYYE UÇAR ŞÜkrÜATEŞ AMMAD AHMAD FAROOQI Department of Anatomy Faculty of MedicineYozgat Bozok UniversityYozgatTurkey Department of Mechanical and Aerospace Engineering Case Western Reserve UniversityClevelandOhioUSA Department of Histology and Embriology Faculty of MedicineYozgat Bozok UniversityYozgatTurkey Department of Anatomy Faculty of DentistryAnkara UniversityAnkaraTurkey Department of Medical Biology Faculty of MedicineAfyonkarahisar Health Sciences UniversityAfyonTurkey Department of Anatomy Faculty of MedicineErciyes UniversityKayseriTurkey Department of Molecular Oncology Institute of Biomedical and Genetic Engineering(IBGE)IslamabadPakistan

Melatonin is a versatile indolamine synthesized and secreted by the pineal gland in response to the photoperiodic information received by the retinohypothalamic signaling *** has many benefits,such as organizing circadian rhythms and acting as a powerful *** aimed to show the antitumor effects of melatonin in both in vivo and in vitro models through the mammalian target of rapamycin(mTOR)signaling pathway and the Argyrophilic Nucleolar Regulatory Region(AgNOR),using the Microcomputed Tomography(Micro CT).Ehrlich ascites carcinoma(EAC)cells were administered into the mice by subcutaneous *** with solid tumors were injected intraperitoneally with 50 and 100 mg/kg melatonin for 14 *** measurements for the taken tumors were made with micro-CT imaging,immunohistochemistry(IHC),real-time polymerase chain reaction(PCR)and ***,the tumor tissue volume in the Tumor+100 mg/kg melatonin group was significantly lower than that in the other groups in the data obtained from micro-CT *** the IHC analysis,the groups treated with Tumor+100 mg/kg melatonin were compared when the mTOR signaling pathway and factor 8(F8)expression were compared with the control *** was determined that there was a significant decrease(p<0.05).Significant differences were found in the total AgNOR area/nuclear area(TAA/NA)ratio in the treatment groups(p<0.05).Furthermore,there were significant differences between the amount of mTOR mRNA for the phosphatidylinositol 3-kinase(PI3K),AKT Serine/Threonine Kinase(PKB/AKT)genes(p<0.05).Cell apoptosis was evaluated with Annexin V in an in vitro study with different doses of melatonin;It was observed that 100µg/mL melatonin dose caused an increase in the apoptotic cell *** this study,we have reported anti-tumor effects of melatonin in cell culture studies as well as in mice *** characterization of the melatonin-mediated cancer inhibitory effects will be valuable in advanc

关键词： Signaling pathway Apoptosis Real-time PCR AgNOR

Subpopulations of regulatory T cells are associated with subclinical atherosclerotic plaques,levels of LDL,and cardiorespiratory fitness in the elderly

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Journal of Sport and Health Science 2024年第3期13卷 288-296,I0002页

作者： Tim Böttrich Pascal Bauer Vincent Gröβer Magdalena Huber Hartmann Raifer Torsten Frech Svenja Nolte Theresa Dombrowski Franz Cemic Natascha Sommer Robert Ringseis Klaus Eder Karsten krüger Christopher Weyh Department of Exercise Physiology and Sports Therapy Institute of Sports ScienceJustus-Liebig-UniversityGiessen 35394Germany Department of Cardiology and Angiology Justus-Liebig-University GiessenGiessen 35392Germany Institute for Systems Immunology Center for Tumor und ImmunologyMarburg 35032Germany TH Mittelhessen Department of Computer ScienceUniversity of Applied Sciences GiessenGiessen 35390Germany Department of Internal Medicine Universities of Giessen and Marburg Lung Center(UGMLC)Member of the German Center for Lung Research(DZL)Giessen 35394Germany Excellence Cluster Cardio-Pulmonary Institute(CPI) Justus-Liebig UniversityGiessen 35394Germany Institute of Animal Nutrition and Nutrition Physiology Justus-Liebig-University GiessenGiessen 35390Germany

Background:Atherosclerosis forms the pathological basis for the development of cardiovascular *** pathological processes initially develop without clinically relevant symptoms,the identification of early markers in the subclinical stage plays an important role for initiating early *** is evidence that regulatory T cells(Tregs)are involved in the development of ***,the present study aimed to identify and investigate associations with Tregs and their subsets in a cohort of healthy elderly individuals with and without subclinical atherosclerotic plaques(SAP).In addition,various lifestyle and risk factors,such as cardiorespiratory fitness,were investigated as associated ***:A cross-sectional study was performed in 79 participants(male:n=50;age=63.6±3.7 years;body mass index=24.9±3.1 kg/m2;mean±SD)who had no previous diagnosis of chronic disease and were not taking *** of the carotids to identify SAP,cardiovascular function measurement for vascular assessment and a cardiorespiratory fitness test to determine peak oxygen uptake were ***,tests were conducted to assess blood lipids and determine glucose *** of Tregs and their subtypes(resting(rTregs)and effector/memory(mTregs))was performed by 8-chanel flow *** were categorized according to atherosclerotic plaque *** and logistic regression models were used to analyze associations between ***:SAP was detected in a total of 29 *** participants with plaque were older(64.8±3.6 years vs.62.9±3.5 years)and had higher peripheral systolic blood pressure(133.8±14.7 mmHg vs.125.8±10.9 mmHg).The participants with SAP were characterized by a lower percentage of rTregs(28.8%±10.7%vs.34.6%±10.7%)and a higher percentage of mTregs(40.3%±14.7%vs.30.0%±11.9%).Multiple logistic regression identified age(odds ratio(OR)=1.20(95%confidence interval(95%CI):1.011.42))and

关键词： Cardiorespiratory fitness Elderly Regulatory T cells Subclinical atherosclerosis

Rethinking neurodegenerative diseases:neurometabolic concept linking lipid oxidation to diseases in the central nervous system

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Neural Regeneration Research 2024年第7期19卷 1437-1445页

作者： Steinunn Sara Helgudóttir Anne Skøttrup Mørkholt Jacek Lichota Preben Bruun-Nyzell Mads Christian Andersen Nanna Marie Juhl kristensen Amanda.krøger Johansen Mikela Reinholdt Zinn Hulda Maria Jensdóttir John Dirk Vestergaard Nieland 2N Pharma ApS NOVI Science ParkAalborgDenmark Molecular Pharmacology Group Department of Health Science and TechnologyAalborg UniversityAalborgDenmark

Currently,there is a lack of effective medicines capable of halting or reve rsing the progression of neurodegenerative disorde rs,including amyotrophic lateral sclerosis,Parkinson s disease,multiple sclerosis,or Alzheimer s *** the unmet medical need,it is necessary to reevaluate the existing para digms of how to to rget these *** considering neurodegenerative diseases from a systemic neurometabolic perspective,it becomes possible to explain the shared pathological *** innovative approach presented in this paper draws upon exte nsive research conducted by the authors and researchers *** this review,we highlight the importance of metabolic mitochondrial dysfunction in the context of neurodegenerative *** provide an overview of the risk factors associated with developing neurodegenerative disorders,including genetic,epigenetic,and environmental fa ***,we examine pathological mechanisms implicated in these diseases such as oxidative stress,accumulation of misfolded proteins,inflammation,demyelination,death of neurons,insulin resistance,dysbiosis,and neurotransmitter ***,we outline a proposal for the restoration of mitochondrial metabolism,a crucial aspect that may hold the key to facilitating curative therapeutic interventions for neurodegenerative disorders in forthcoming advancements.

关键词： brain disease carnitine palmitoyl transferase 1 epigenetics metabolism gut microbiome mitochondrial dysfunction neurodegeneration oxidative stress

Sc元素添加对双辊铸轧Al−Cu−Li−Mg−Zr基合金热处理的影响

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Transactions of Nonferrous Metals Society of China 2024年第6期34卷 1759-1773页

作者： Rostislav krÁLÍK Barbora KŘIVSKÁ Lucia BAJTOŠOVÁ Mykhailo STOLBCHENKO Mirko SCHAPER Olexandr GRYDIN Miroslav CIESLAR Department of Physics of Materials Faculty of Mathematics and PhysicsCharles UniversityKe Karlovu 512116PragueCzech Republic Department of Materials Science Faculty of Mechanical EngineeringUniversity of PaderbornWarburger Straße 10033098PaderbornGermany

提出制备含Sc的Al−Cu−Li−Mg−Zr基合金带材的工艺方案。即先采用双辊铸轧技术制备近净形状的3 mm厚带材,再对其进行均匀化/固溶处理。研究两种Al−Cu−Li−Mg−Zr基双辊铸轧合金,其中一种添加质量分数为0.17%的Sc,另一种未添加Sc。两种合金... 详细信息

提出制备含Sc的Al−Cu−Li−Mg−Zr基合金带材的工艺方案。即先采用双辊铸轧技术制备近净形状的3 mm厚带材,再对其进行均匀化/固溶处理。研究两种Al−Cu−Li−Mg−Zr基双辊铸轧合金,其中一种添加质量分数为0.17%的Sc,另一种未添加Sc。两种合金均先在300℃下退火30 min,然后在450℃下退火30 min以及530℃下退火30 min,随后进行室温水淬。前两段退火后组织中生成了细小、弥散的Al_(3)Zr/Al_(3)(Sc,Zr)颗粒。最后的退火步骤起到了均匀化/固溶处理的作用。双辊铸轧材料的细小晶粒结构使含有主要合金元素的原始颗粒在较短的退火时间内溶解。缩短保温时间可以限制表面层中Li的耗尽和Al_(3)Zr/Al_(3)(Sc,Zr)弥散相的明显粗化。铸态含Sc材料已经具有明显细小的晶粒结构,而经均匀化/固溶处理后生成的Al_(3)(Sc,Zr)弥散相抑制了晶粒在高温下发生粗化。在后续180℃下时效处理后,形成了θʹ(Al_(2)Cu)、T1(Al_(2)CuLi)和S'(Al_(2)CuMg)强化相。在峰值时效状态下,屈服强度提高了200 MPa,这一数值与类似直接冷却铸造材料的相当,从而证实了所提方案的合理性。

关键词：显微组织力学性能 Al−Cu−Li基合金 Sc合金化双辊铸轧

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Optimization of Biofuel Formulation by Mixture Design

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Advances in Chemical Engineering and Science 2024年第1期14卷 48-56页

作者： Konan Edmond Kouassi Abollé Abollé Kouamé Olivier-Marc Kouakou David Boa N’guessan Raymond kré Kouassi Benjamin Yao Laboratory of Thermodynamics and Physical Chemistry of the Environment (LTPCM) UFR-SFA University of Nangui ABROGOUA Abidjan C&#244te d’Ivoire Laboratory of Fundamental and Applied Physics (LPFA) UFR-SFA University of Nangui ABROGOUA Abidjan C&#244te d’Ivoire Laboratory of Industrial Processes for the Synthesis of the Environment and New Energies (LAPISEN) of the Félix Houphouë t Boigny National Polytechnic Institute Yamoussoukro C&#244te d’Ivoire

With the full growth of energy needs in the world, several studies are now focused on finding renewable sources. The aim of this work is to optimise biofuel formulation from a mixture design by studying physical properties, such as specific gravity and kinematic viscosity of various formulated mixtures. Optimization from the mixture plan revealed that in the chosen experimental domain, the optimal conditions are: 40% for used frying oil (UFO), 50% for bioethanol and 10% for diesel. These experimental conditions lead to a biofuel with a density of 0.84 and a kinematic viscosity of 2.97 cSt. These parameters are compliant with the diesel quality certificate in tropical areas. These density and viscosity values were determined according to respective desirability values of 0.68 and 0.75.

关键词： Biofuel Optimization Mixture Design

Changes in carbon stocks of soil and forest floor in black pine plantations in Turkey

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Journal of Forestry Research 2021年第1期32卷 339-347页

作者： SükrüTeoman Güner Dilek Güner General Directorate of Forestry Research Institute for Forest Soil and Ecology26160 EskisehirTurkey

The objectives of this study were:(1)to determine carbon stock changes in the soil and forest floor of black pine(Pinus nigra ***)plantations in Turkey;(2)to determine the effects of thinning on annual carbon accumulation in both;and,(3)to investigate relationships between annual carbon storage in soil and forest floor and stand characteristics of black *** were taken in 90 plots from stands at the pole(dbh=11.0–19.9 cm)and sawlog(dbh=20.0–35.9 cm)*** analyses of soil and forest floor samples showed that in unthinned plantations signifi cant organic carbon was sequestered an average of 1.47 Mg ha^−1 a^−1 in the soil and 0.20 Mg ha^−1 a^−1 in the forest *** carbon sequestered annually in the soil was signifi cantly lower in thinned than in unthinned stands,while diff erences in the forest floor were insignifi *** were positive correlations between carbon sequestered in the soil and stand age,average DBH,mean stand height,basal area,and site *** sequestered the forest floor increased with basal *** a result,carbon sequestered in the soil should not be ignored in greenhouse gas inventories because carbon stored belowground was approximately 70%of the aboveground pool.

关键词： Pinus nigra Belowground Forest floor Carbon sequestration Thinning

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

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National Science Review 2022年第3期9卷 110-118页

作者： Xiaolei Wang Ming Tang Jeff Moyen Di Wang Alfred kr?ner Chris Hawkesworth Xiaoping Xia Hangqiang Xie Carl Anhaeusser Axel Hofmann Junyong Li Linsen Li State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University School of Earth and Space Sciences Peking University Laboratoire Magmas et Volcans UMR6524 Université de LyonUJM-UCA-CNRS-IRD Institut für Geowissenschaften Universit?t Mainz Department of Earth Sciences University of Bristol State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Economic Geology Research Unit University of the Witwatersrand Department of Geology University of Johannesburg

The recycling of supracrustal materials, and in particular hydrated rocks, has a profound impact on mantle composition and thus on the formation of continental crust, because water modifies the physical properties of lithological systems and the mechanisms of partial melting and fractional fractionation. On the modern Earth, plate tectonics offers an efficient mechanism for mass transport from the Earth’s surface to its interior, but how far this mechanism dates back in the Earth’s history is still uncertain. Here, we use zircon oxygen(O) isotopes to track recycling of supracrustal materials into the magma sources of early Archean igneous suites from the Kaapvaal Craton, southern Africa. The mean δ18O values of zircon from TTG(tonalite–trondhjemite–granodiorite) rocks abruptly increase at the Paleo-Mesoarchean boundary(ca.3230 million years ago; Ma), from mantle zircon values of 5‰–6‰ to approaching 7.1‰, and this increase occurs in ≤3230 Ma rocks with elevated Dy/Yb ratios. The18O enrichment is a unique signature of low-temperature water–rock interaction on the Earth’s surface. Because the later phase was emplaced into the same crustal level as the older one and TTG magmas would derive from melting processes in the garnet stability field(>40 km depth), we suggest that this evident shift in TTG zircon O isotopic compositions records the onset of recycling of the mafic oceanic crust that underwent seawater hydrothermal alteration at low temperature. The onset of the enhanced recycling of supracrustal materials may also have developed elsewhere in other Archean cratons and reflects a significant change in the tectonic realm during craton formation and stabilization, which may be important processes for the operation of plate tectonics on early Earth.

关键词： zircon oxygen isotopes TTG plate tectonics deep recycling Paleo-Mesoarchean boundary