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Customized scaffolds for large bone defects using 3D‑printed modular blocks from 2D‑medical images

Bio-Design and Manufacturing 2024年第1期7卷 74-87页

作者： Anil AAcar Evangelos Daskalakis Paulo Bartolo Andrew Weightman Glen Cooper Gordon Blunn Bahattin koc Faculty of Engineering and Natural sciences Sabanci UniversityIstanbul 34956Türkiye D Bioprinting Laboratory Sabanci University Nanotechnology Research and Application CenterIstanbul 34956Türkiye school of Mechanical Aerospace and Civil EngineeringManchester Institute of BiotechnologyUniversity of ManchesterManchester M139PLUK singapore Centre for 3D Printing School of Mechanical and Aerospace EngineeringNanyang Technological UniversitySingapore 639798Singapore school of Pharmacy and Biomedical sciences University of PortsmouthPortsmouth PO12UPUK

Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering *** use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and ***,these sophisticated techniques can be timeconsuming,labor-intensive,and ***,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma *** this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a *** modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during *** proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or *** algorithm can generate both patient-specific and average bone ***,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or *** algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM *** and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects.

关键词： Additive manufacturing Modular scaffolds Large bone defect Customized scaffold design Patient-specific scaffolds

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The first record of a Konservat-Lagerstätten in which early post-settlement stages of fossil archaeobalanids(Cirripedia:Balanomorpha)are preserved

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Integrative Zoology 2024年第2期19卷 200-223页

作者： Tomáš kocÍ Rok GAŠPARIC John BUCKERIDGE Martina kocOVÁ VEsELsKÁ Aleš ŠOsTER Ivancická581 PragueCzech Republic Palaeontological Department Natural History MuseumNational MuseumPragueCzech Republic Oertijdmuseum Bosscheweg 80Boxtel5293 WBThe Netherlands Institute for Palaeobiology and Evolution Novi TrgKamnikSlovenia Earth and Oceanic systems Group RMIT UniversityMelbourneAustralia Museums Victoria CarltonVictoriaAustralia Department of Paleobiology and Paleoecology Institute of Geology of the Czech Academy of SciencesPragueCzech Republic Institute of Geology and Palaeontology Charles UniversityPragueCzech Republic Faculty of Natural sciences and Engineering University of LjubljanaLjubljanaSlovenia

A diverse sessile barnacle fauna from a Miocene shallow-water deposit at Dolnja stara vas in slovenia is *** includes the first descriptions of early post settlement juveniles of Actinobalanus sloveniensis attached to mangrove *** represent three distinct growth phases,the earliest being interpreted as being less than 24 h post settlement,the others being 1 to 2 days post *** assessment of their taphonomy is *** adult balanomorphs are attached to a variety of organic substrates,including mangrove leaves and branches,fragments of the conifers?Taxodioxylon,Carapoxylon,pine cones,molluscs,and cetacean *** barnacles include ***,Amphibalanus venustus,and Perforatus perforatus—many with opercula retained within the *** retains some of the original shell *** is the second record of barnacle–plant associations from the Central Paratethys from Kamnik and *** paleoecology and paleogeography of the site are discussed.

关键词： acorn barnacles barnacle metamorphosis epibiont paleoecology taxonomy

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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(psignificant differences were found in the total AgNOR area/nuclear area(TAA/NA)ratio in the treatment groups(psignificant differences between the amount of mTOR mRNA for the phosphatidylinositol 3-kinase(PI3K),AKT serine/Threonine Kinase(PKB/AKT)genes(psis 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

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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

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Fluid Inclusion studies and Geochemistry of Rare Earth Elements of Hydrothermal Fluorites from Pohrenk,Kirsehir,Central Turkey

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Acta Geologica sinica(English Edition) 2001年第1期75卷 59-65页

作者： s.kr. koc Ali RECBER Geology Department Ankara UniversityAnkara 06100Turkey General Directorate of Mineral Research and Exploration Ankara

Fluorite mineralization occurs along fractures and cracks of Middle Eocene and Pliocene limestones and marls in the north and northeast of the P?hrenk region (?i?ekdagi, Kirsehir). Tb/Ca – Tb/La and Y/Ho ratios were obtained from REE contents of fluorites which have revealed that mineralization is of hydrothermal type. Negative Ce anomalies and positive Eu anomalies reflect that hydrothermal solutions once had high oxygen fugacity. Fluid inclusion studies indicate that homogenization temperatures of mineralization varied between 90°C and 200°C, and hydrothermal solutions are composed of NaCl + KCl + MgCl2 + H2O. In addition, salinity measurements show that hydrothermal solutions were mixed with meteoric or rock formation water. Geologic setting, REE geochemistry and fluid inclusion studies suggest that mineralization was deposited from a solution generated by mixing of magmatic and meteoric water under epithermal conditions.

关键词： fluorite rare earth elements fluid inclusions

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Geochemistry of Kestelek Colemanite Deposit, Bursa, Turkey

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Journal of Earth science 2017年第1期28卷 63-77页

作者： s.kr. koc Ozge Kavrazh ismail kocak Faculty of Department of Geological Engineering Ankara University Ankara 06100 Turkey Graduate school of Natural and Applied sciences Ankara University Ankara 06100 Turkey Department of Geological Engineering Bozok University Yozgat 66100 Turkey

The Kestelek borate deposit has been the subject of geological and mineralogical research over the last decades, but major and trace element geochemistry of this deposit was first investigated in the present study. A total of 22 samples collected from surface exposures and different depths of deposit in boreholes（e.g., lower, middle and upper） comprise the material of this study. Major, trace and REE element analyses of samples were conducted with ICP-Ms and ICP-Es methods. The Kestelek borate deposit of Miocene age was formed in playa lakes in an intermountain closed basin which was developed in volcanically and seismically active areas associated with growth faults and grabens affected the whole Anatolia at the beginning of Paleogene. Only colemanite was found as the borate mineral accompanied in lesser amount by calcite, aragonite, smectite, illite, chlorite, corrensite, heulandite and quartz. In colemanite samples, all major elements, except for Ca, show depletion trends with respect to average of earth crust and andesite. For the trace elements, Li, Cs, sb, As, sr and se are characterized by significantly high concentrations. Evaluation of element concentrations and geochemical characteristics reveal that As, Cs, sb and Li are of detrital origin, se together with B and Ca are of non-detrital and sr is indicative of both detrital and non-detrital origin. REE distributions indicate that at least two different depositional regimes prevail in the environment. Corrensite, a clay mineral forming in lake waters, is derived from volcanism. Negative Ce and positive Eu anomalies are indicative of contribution from hydrothermal solutions and fluids.

关键词： borate mineralogy geochemistry REE Kestelek Turkey.

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Factors Controlling Low Uranium and Thorium Concentrations in the Cayirhan Bituminous shales(CBs)in the Beypazari(Ankara)Area,Turkey

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Acta Geologica sinica(English Edition) 2014年第1期88卷 248-252,I0009,I0010,253-259页

作者： Berna Yavuz PEHLIVANLI s.kr. koc Ali sARI Hilal ENGIN Department of Geological Engineering Faculty of Engineering and Architecture Bozok University Department of Geological Engineering Faculty of Engineernig Ankara University Graduate school of Natural and Applied sciences Ankara University

In this study uranium and thorium contents and depositional characteristics of ay rhan bituminous shales（ Bs）, west of Ankara（central Anatolia）, are investigated. samples used were collected from boreholes opened by Park Holding Ltd. A total of 25 samples were taken from bituminous shale levels in boreholes drilled at 6 different locations in the study area. The H rka formation which hosts bituminous shale deposits is a volcanosedimentary sequence and all lithofacies indicate that a lacustrine environment where the water level was continuously changed. In addition to hydrocarbon generation potential, bituminous shales also accumulate significant amount of radioactive elements such as uranium and thorium. The average uranium and thorium concentrations of Bs（1.83/2.62 ppm） are much lower than averages of UC, NAsK and PAAs（uranium： 2.70/2.66/3.10 ppm; thorium： 8.50/12.30/14.60 ppm）. Low uranium contents in comparison to those of similar lacustrine environments might be attributed to that waters of depositional environment of Bs contain low concentration of dissolved uranium and redox conditions were of oxic and dioxic character. Correlation data indicate that U and Th have a similar source and are associated predominantly with clays and phosphates and dominantly with organic material. Radioactive elements in the basin might be derived from Paleozoic granites and metamorphites（e.g. gneiss, schist） which comprise the basement and volcanism which was active in the region throughout the Miocene period. These elements are probably associated with uraniferous phosphate minerals（e.g. autunite, torbernite） which occur in granite, gneiss and schist. Bs with average TOC content of 10.96 % shows very good/perfect source rock potential. Positive correlations between Gamma-Ray values and U, Th and K concentrations imply that radioactivity might be originated from these three elements.

关键词： Uranium and Thorium concentrations ay rhan bituminous shales Beypazar area Turkey

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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

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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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First-principles study of the structural,elastic,electronic,optical,and vibrational properties of intermetallic Pd_2Ga

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Chinese Physics B 2012年第3期21卷 341-348页

作者： Yildirim A koc H Deligoz E Department of Physics Siirt University Department of Physics Aksaray University

The structural, elastic, electronic, optical, and vibrational properties of the orthorhombic Pd2Ga compound are investigated using the norm-conserving pseudopotentials within the local density approximation in the frame of density functional theory. The calculated lattice parameters have been compared with the experimental values and found to be in good agreement with these results. The second-order elastic constants and the other relevant quantities, such as the Young＇s modulus, shear modulus, Poisson＇s ratio, anisotropy factor, sound velocity, and Debye temperature, have been calculated. It is shown that this compound is mechanically stable after analysing the calculated elastic constants. Furthermore, the real and imaginary parts of the dielectric function and the optical constants, such as the optical dielectric constant and the effective number of electrons per unit cell, are calculated and presented. The phonon dispersion curves are derived using the direct method. The present results demonstrate that this compound is dynamically stable.

关键词： Pd2Ga vibrational properties optical properties elastic constants

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