54 research outputs found

    Namotani kondenzator realizovan u Fused Fabricated Filament tehnologiji

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    Ideja za razvoj ovih 3D štampanih kondenzatora y FFF (Fused Fabricated Filament) tehnologiji je proistekla iz istraživanja u oblasti 3D štampe. Provodni ABS kompozitni materijal je korišćen za proizvodnju 3D štampanih elektroda namotanog kondenzatora primenom komercijalno dostupnog 3D štampača (nano3Dprint A2200). Kondenzator sadrži Arhimedove spiralne elektrode čije su dimenzije: unutrašnji prečnik 10mm , debljina elektroda 0,6 mm, visina 10 mm

    PARALLEL ANALYSIS OF IMPEDANCE CHANGE OF FERRITE MULTILAYER CHIP INDUCTORS AND SMALL MULTI-APERTURE CORES IN THE EMI RANGE

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    Dobijanje čip induktora višeslojnom tehnologijom (spajanjem zelenih feritnih listova na kojima su naneti delovi namotaja štampanjem PdAg paste) opisano je u najkraćem. Svojstva MnZn ferita u EMI opsegu data su na osnovu merenja impedanse Z(ω) i proračuna realativne permeabilnosti μr i dielektrične konstante εr. Merenje impedanse čip induktora različitih dimenzija i konstrukcije vršeno je takoće u EMI opsegu. Paralelno su u istom frekventnom opsegu vršena merenja impedanse na malim jezgrima sa više otvora dobijenim presovanjem i sinterovnjem istog materijala. Za kvalitativno-kvantitativnu analizu kao model usvojeno je paralelno RLC kolo. Dobijeni rezultati upoređeni su međusobno i sa najboljim literaturnim rezultatima

    Ectopic bone formation by mesenchymal stem cells derived from human term placenta and the decidua

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    Mesenchymal stem cells (MSCs) are one of the most attractive cell types for cell-based bone tissue repair applications. Fetal-derived MSCs and maternal-derived MSCs have been isolated from chorionic villi of human term placenta and the decidua basalis attached to the placenta following delivery, respectively. Chorionic-derived MSCs (CMSCs) and decidua-derived MSCs (DMSCs) generated in this study met the MSCs criteria set by International Society of Cellular Therapy. These criteria include: (i) adherence to plastic; (ii) >90% expression of CD73, CD105, CD90, CD146, CD44 and CD166 combined with <5% expression of CD45, CD19 and HLA-DR; and (iii) ability to differentiate into osteogenic, adipogenic, and chondrogenic lineages. In vivo subcutaneous implantation into SCID mice showed that both bromo-deoxyuridine (BrdU)-labelled CMSCs and DMSCs when implanted together with hydroxyapatite/tricalcium phosphate particles were capable of forming ectopic bone at 8-weeks post-transplantation. Histological assessment showed expression of bone markers, osteopontin (OPN), osteocalcin (OCN), biglycan (BGN), bone sialoprotein (BSP), and also a marker of vasculature, alpha-smooth muscle actin (α-SMA). This study provides evidence to support CMSCs and DMSCs as cellular candidates with potent bone forming capacity.Gina D. Kusuma, Danijela Menicanin, Stan Gronthos, Ursula Manuelpillai, Mohamed H. Abumaree, Mark D. Pertile, Shaun P. Brennecke, Bill Kalioni

    Loss of Grem1-lineage chondrogenic progenitor cells causes osteoarthritis

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    Published online: 31 October 2023Osteoarthritis (OA) is characterised by an irreversible degeneration of articular cartilage. Here we show that the BMP-antagonist Gremlin 1 (Grem1) marks a bipotent chondrogenic and osteogenic progenitor cell population within the articular surface. Notably, these progenitors are depleted by injury-induced OA and increasing age. OA is also caused by ablation of Grem1 cells in mice. Transcriptomic and functional analysis in mice found that articular surface Grem1-lineage cells are dependent on Foxo1 and ablation of Foxo1 in Grem1-lineage cells caused OA. FGFR3 signalling was confirmed as a promising therapeutic pathway by administration of pathway activator, FGF18, resulting in Grem1-lineage chondrocyte progenitor cell proliferation, increased cartilage thickness and reduced OA. These findings suggest that OA, in part, is caused by mechanical, developmental or age-related attrition of Grem1 expressing articular cartilage progenitor cells. These cells, and the FGFR3 signalling pathway that sustains them, may be effective future targets for biological management of OA.Jia Q. Ng, Toghrul H. Jafarov, Christopher B. Little, Tongtong Wang, Abdullah M. Ali, YanMa, Georgette A. Radford, Laura Vrbanac, Mari Ichinose, Samuel Whittle, David J. Hunter, Tamsin R. M. Lannagan, Nobumi Suzuki, JarradM. Goyne, Hiroki Kobayashi, Timothy C. Wang, David R. Haynes, Danijela Menicanin, Stan Gronthos, Daniel L. Worthley, Susan L. Woods and Siddhartha Mukherje

    Transcriptional landscape of bone marrow-derived very small embryonic-like stem cells during hypoxia

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    <p>Abstract</p> <p>Background</p> <p>Hypoxia is a ubiquitous feature of many lung diseases and elicits cell-specific responses. While the effects of hypoxia on stem cells have been examined under <it>in vitro </it>conditions, the consequences of <it>in vivo </it>oxygen deprivation have not been studied.</p> <p>Methods</p> <p>We investigated the effects of <it>in vivo </it>hypoxia on a recently characterized population of pluripotent stem cells known as very small embryonic-like stem cells (VSELs) by whole-genome expression profiling and measuring peripheral blood stem cell chemokine levels.</p> <p>Results</p> <p>We found that exposure to hypoxia in mice mobilized VSELs from the bone marrow to peripheral blood, and induced a distinct genome-wide transcriptional signature. Applying a computationally-intensive methodology, we identified a hypoxia-induced gene interaction network that was functionally enriched in a diverse array of programs including organ-specific development, stress response, and wound repair. Topographic analysis of the network highlighted a number of densely connected hubs that may represent key controllers of stem cell response during hypoxia and, therefore, serve as putative targets for altering the pathophysiologic consequences of hypoxic burden.</p> <p>Conclusions</p> <p>A brief exposure to hypoxia recruits pluripotent stem cells to the peripheral circulation and actives diverse transcriptional programs that are orchestrated by a selective number of key genes.</p

    INK-JET PRINTED CPW INDUCTOR IN FLEXIBLE TECHNOLOGY WITH CONDUCTIVE LAYER CONTAINING SILVER NANOPARTICLES

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    U ovom radu je predstavljen koplanarni induktor u fleksibilnoj tehnologiji dobijen postupkom ink-jet štampanja. Prikazani su projektovanje, simulacija, proizvodnja, merenja i karakterizacija ovih struktura. Ova tehnologija predstavlja rešenje za veoma jeftinu masovnu proizvodnju. Koplanarni induktori, koji su razvijeni za fleksibilnu štampanu elektroniku, su dobijeni na polimernoj podlozi sa provodnim slojem od nanočestičnog srebra.In this paper we present an ink-jet printed coplanar waveguide (CPW) inductors in flexible technology. We show design, simulation, fabrication, characterization and measurement technique of such devices. This is solution for ultra low-cost mass production. CPW inductors were developed as a technology for much simpler and faster fabrication on/in plastic foil. Structures are printed on Kapton substrate with polyamide silver nanoparticle ink

    Identification of a common gene expression signature associated with immature clonal mesenchymal cell populations derived from bone marrow and dental tissues

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    Mesenchymal stem/stromal cell-like populations derived from adult bone marrow (BMSC), dental pulp (DPSC), and periodontal ligament (PDLSC) have the ability to differentiate into cells of mesenchymal and non-mesenchymal tissues in vitro and in vivo. However, culture-expanded MSC-like populations are a heterogeneous mix of stem/committed progenitor cells that exhibit altered growth and developmental potentials. In the present study we isolated and characterized clonal populations of BMSCs, DPSCs, and PDLSCs to identify potential biomarkers associated with long-lived multipotential stem cells. Microarray analysis was used to compare the global gene expression profiles of high growth/multipotential clones with low growth potential cell clones derived from 3 stromal tissues. Cross-comparison analyses of genes expressed by high growth/multipotential clones derived from bone marrow, dental pulp, and periodontal ligament identified 24 genes that are differentially up-regulated in all tissues. Notably, the transcription factors, E2F2, PTTG1, TWIST-1, and transcriptional cofactor, LDB2, each with critical roles in cell growth and survival, were highly expressed in all stem cell populations examined. These findings provide a model system for identifying a common molecular fingerprint associated with immature mesenchymal stem-like cells from different organs and implicate a potential role for these genes in MSC growth and development.Danijela Menicanin, P. Mark Bartold, Andrew C. W. Zannettino and Stan Grontho

    Cementum and periodontal ligament regeneration

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    The unique anatomy and composition of the periodontium make periodontal tissue healing and regeneration a complex process. Periodontal regeneration aims to recapitulate the crucial stages of wound healing associated with periodontal development in order to restore lost tissues to their original form and function and for regeneration to occur, healing events must progress in an ordered and programmed sequence both temporally and spatially, replicating key developmental events. A number of procedures have been employed to promote true and predictable regeneration of the periodontium. Principally, the approaches are based on the use of graft materials to compensate for the bone loss incurred as a result of periodontal disease, use of barrier membranes for guided tissue regeneration and use of bioactive molecules. More recently, the concept of tissue engineering has been integrated into research and applications of regenerative dentistry, including periodontics, to aim to manage damaged and lost oral tissues, through reconstruction and regeneration of the periodontium and alleviate the shortcomings of more conventional therapeutic options. The essential components for generating effective cellular based therapeutic strategies include a population of multi-potential progenitor cells, presence of signalling molecules/inductive morphogenic signals and a conductive extracellular matrix scaffold or appropriate delivery system. Mesenchymal stem cells are considered suitable candidates for cell-based tissue engineering strategies owing to their extensive expansion rate and potential to differentiate into cells of multiple organs and systems. Mesenchymal stem cells derived from multiple tissue sources have been investigated in pre-clinical animal studies and clinical settings for the treatment and regeneration of the periodontium.Danijela Menicanin, K. Hynes, J. Han, S. Gronthos and P. M. Bartol
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