1,148 research outputs found
First person - Carina Lund
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Disease Models & Mechanisms (DMM), helping early-career researchers promote themselves alongside their papers. Carina Lund is first author on 'Characterization of the human GnRH neuron developmental transcriptome using a GNRH1-TdTomato reporter line in human pluripotent stem cells', published in DMM. Carina is a PhD student in the lab of Taneli Raivio at the University of Helsinki, Finland, investigating neuronal differentiation from human pluripotent stem cells.Non peer reviewe
Pre-clinical screening of novel two-photon photopolymerized biomaterials for bone implantation.
No full textWirkung verschiedener Biomaterialien auf Osteoblasten in vitro
No full textKnochenschäden infolge von traumatischen Verletzungen, Tumorresektionen oder operativen Rekonstruktionen erfordern die Anwendung von Knochenersatzmaterialien. Gegenwärtig verfügbare Transplantate, wie die Verwendung von autologen oder allogenen Knochenmaterialen, und Allotransplantaten mit demineralisierter Matrix oder osteogenen Proteinen sind nur limitiert verfügbar. Das Forschungsgebiet der Knochenregenerationsmedizin hat sich aufgrund dieser Notwendigkeit rasch weiterentwickelt und die Entwicklung von Biomaterialien als Knochenersatz stellt dabei einen wichtigen Forschungsbereich dar.
Ziel dieser Diplomarbeit war die Untersuchung von Effekten potentieller Biomaterialen für den Bereich „bone tissue engeneering“. Getestet wurden zwei verschiedene Klassen von abbaubaren Biomaterialien. Einerseits wurden Einflüsse von Gelatine und andererseits von einem synthetischen Copolymer auf den Differenzierungsprozess und der Mineralisationsfähigkeit von Osteoblasten untersucht. Zur Beurteilung dieser Materialien wurden Parameter wie Zellviabilität und knochenspezifische Marker (Alkalische Phosphatase Aktivität und Matrixmineralisation) herangezogen.
Weder das Verfahren zur Gewinnung der Gelatine, noch Unterschiede in physikochemische Parameter wie isoelektrischer Punkt oder Gelierfähigkeit hatten einen Einfluss auf die Alkalische Phosphatase Aktivität MC3T3-E1 Zellen über den getesteten Zeitraum. Aktive Alkalische Phosphatase konnte in sämtlichen Gruppen mittels Färbemethode detektiert werden. Die Fähigkeit extrazelluläre Matrix zu mineralisieren wurde jedoch bei allen Gelatinegruppen gefördert. Physikochemische Parameter und Gewinnungsmethode der Gelatine bewirkten deutliche Unterschiede in der Matrixmineralisation. Sämtliche Beschichtungen, die als Einzelkomponente Gelatine Typ B enthielten oder in einer Mischung mit Gelatine Typ B gefertigt wurden, führten im Vergleich zu den anderen Gelatinebeschichtungen zu einer höheren Matrixmineralisation.
Bei Gegenüberstellung beider Ausgangsmaterialien als Scaffoldmaterial hinsichtlich ihres Effektes auf Zellviabilität und –proliferation, Osteoblastendifferenzierung und Mineralisation extrazellulärer Matrix, zeigte sich in sämtlichen Experimenten, dass LCM6 einen deutlich stärkeren Einfluss auf zelluläre Prozesse ausübt als LCM3. Primären Maus-Osteoblasten konnten auf dem Materialtyp LCM3 adhärieren, proliferieren, differenzieren und schließlich synthetisierte Matrix mineralisieren. In den in vitro Experimenten resultierte für diese Gruppe, trotz verminderter Anzahl an metabolisch aktiven Zellen, eine positive Färbung für das Enzym Alkalische Phosphatase und für die Matrixmineralisation. Im Gegensatz dazu kam es beim Biomaterial LCM6 neben der starken Reduktion in Proliferation und Viabilität zu einer Hemmung der Aktivität der Alkalischen Phosphatase und zu einem nur sehr geringen Anstieg an mineralisierter Matrix über 21 Tage.
Die Materialzusammensetzung, vor allem das Verhältnis der Einzelkomponenten zueinander (Lactid, Caprolacton und Methacrylat) und die damit verbundenen Eigenschaften, nehmen laut den erhaltenen Ergebnissen Einfluss auf Proliferation, den Differenzierungsprozess und auf die Matrixmineralisationsfähigkeit. Im Falle des Biomaterial LCM6 erwiesen sich eine Erhöhung des Lactid-Anteils und ein verringerter Prozentsatz an Methacrylat als nicht günstig für die getesteten Zellfunktionsparameter.Bone loss causing from trauma, surgical tumor removal or reconstructive surgeries requires the usage of bone graft substitutes. Current treatments as autologous or allogenic bone grafts, allografts with demineralized matrix or osteogenic proteins are limited available. Therefore the design of biomaterials with osteogenic, osteoinductive and osteoconductive properties become more and more interesting.
In the present diploma thesis work, the effect of potential biomaterials for bone grafting was tested on osteoblast proliferation and differentiation. Two polymers were investigated. One polymer was the macromolecule gelatin and the other one was a synthetic copolymer (LCM) Mouse calvarial derived osteoblasts or MC3T3-E1 cells were cultured on various gelatine coatings or on different photopolymerized LCM discs. Cells were directed to osteoblast lineage by growing them in differentiation media containing ascorbic acid (50µg/ml) and β-glycerophosphate (5mM). To determine effects on osteoblast proliferation, differentiation and mineralization, assays were performed for cell viability and proliferation (MTS-assay), alkaline phosphatase (ALP) activity and mineralized matrix was visualised with alizarin red.
Independent from the extraction method or gel strength of the tested gelatin coatings, osteoblasts attached on the pre-coated surfaces and showed ALP activity in all groups. There was no significant difference observed between the different investigated gelatin types according to ALP activity. But mineralized matrix production was enhanced in the presence of gelatin compared to the control on tissue culture plastic.
Osteoblast attachment and proliferation was also observed by culturing cells on different synthetic polymer-compositions (LCM3 and LCM6). Even if a reduction in the metabolic activity of osteoblasts on LCM3 and LCM6 was monitored, LCM3, but not LCM6, supported alkaline phosphatase expression and matrix mineralization.
In conclusion, both biomaterials showed supporting effects on osteoblast differentiation in vitro. In the process of bone healing, both, osteoblast and osteoclast play a major role. Therefore further experiments have to be established to determine effects on osteoclast development as well as to determine the potency of these materials for in vivo bone formation
Bone healing around titanium implants in a preclinical model of bile duct ligation‐induced liver injury
No full textOBJECTIVES
Chronic liver disease increases the risk for periodontal disease and osteoporotic fractures, but its impacts on bone regeneration remain unknown. Herein, we studied the impact of liver cirrhosis on peri-implant bone formation.
MATERIAL AND METHODS
A total of 20 male Wistar rats were randomly divided into two groups: one with the common bile duct ligated (BDL) and the respective sham-treated control group (SHAM). After four weeks of disease induction, titanium mini-screws were inserted into the tibia. Successful induction of liver cirrhosis was confirmed by the presence of clinical symptoms. Another four weeks later, peri-implant bone volume per tissue volume (BV/TV) and bone-to-implant contact (BIC) were determined by histomorphometric analysis.
RESULTS
Peri-implant bone formation was not significantly different between the SHAM and BDL groups. In the cortical compartment, the median percentage of peri-implant new bone was 10.1% (95% CI of mean 4.0-35.7) and 22.5% (13.8-30.6) in the SHAM and BDL groups, respectively (p = .26). Consistently, the new bone in direct contact with the implant was 18.1% (0.4-37.8) and 23.3% (9.2-32.8) in SHAM and BDL groups, respectively (p = .38). When measuring the medullary compartment, the new bone area was 7.1% (4.8-10.4) and 10.4% (7.2-13.5) in the SHAM and BDL groups, respectively (p = .17). Medullary new bone in direct contact with the implant was 10.0% (1.2-50.4) and 20.6% (16.8-35.3) in SHAM and BDL groups, respectively, and thus comparable between the two groups (p = .46).
CONCLUSIONS
Bile duct ligation has no significant impact on the early stages of peri-implant bone formation
Influence of surface properties on the bondability of electrical steel sheets
No full textAuthor Carina Kern, BScMasterarbeit Universität Linz 2022Arbeit nach Ablauf der Sperre auf den öffentlichen PCs in den Bibliotheken der JKU+Medizin abrufba
Influence of surface properties on the bondability of electrical steel sheets
No full textAuthor Carina Kern, BScMasterarbeit Universität Linz 2022Arbeit nach Ablauf der Sperre auf den öffentlichen PCs in den Bibliotheken der JKU+Medizin abrufba
Probing ISM Structure in Trumpler 14 and Carina i Using the Stratospheric Terahertz Observatory 2
No full textWe present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2. The Trumpler 14/Carina I region is in the western part of the Carina Nebula Complex (CNC), which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 μm transition of [C ii] with a spatial resolution of 48″ and a velocity resolution of 0.17 km s-1. The observations cover a 0.25 by 0.28 area with central position l = 297.34, b = -0.60. The kinematics show that bright [C ii] structures are spatially and spectrally correlated with the surfaces of CO clouds, tracing the photodissociation region (PDR) and ionization front of each molecular cloud. Along seven lines of sight (LOSs) that traverse Tr 14 into the dark ridge to the southwest, we find that the [C ii] luminosity from the H ii region is 3.7 times that from the PDR. In the same LOS, we find in the PDRs an average ratio of 1 : 4.1 : 5.6 for the mass in atomic gas : dark CO gas : molecular gas traced by CO. Comparing multiple gas tracers, including H i 21 cm, [C ii], CO, and radio recombination lines, we find that the H ii regions of the CNC are well described as H ii regions with one side freely expanding toward us, consistent with the Champagne model of ionized gas evolution. The dispersal of the GMC in this region is dominated by EUV photoevaporation; the dispersal timescale is 20-30 Myr.QN/Gao La
Dino Carina. Istruzione, lavoro, studi comparativi. I
No full textDino Carina (1836-1872), studioso toscano di economia e di politica scolastica, a partire dagli anni Sessanta dell’Ottocento compie diversi “viaggi pedagogici” in Francia, Belgio, Germania e Inghilterra. È autore di diversi lavori riguardanti l’educazione comparata: Sulla istruzione primaria e industriale della Francia, dell'Inghilterra, del Belgio (1861), Della istruzione primaria e industriale considerata nelle sue relazioni colla pubblica economia. Nuovi studi comparativi (1868), Dell’ozio in Italia (1870). Ciò nonostante, è un autore ancora poco conosciuto e studiato.
In questo articolo si prende in considerazione il suo contributo al processo di sviluppo degli studi comparativi in educazione in Italia negli anni dell’unificazione nazionale. In particolare, si focalizza l’attenzione sul suo interesse per il contesto socio-politico-culturale nel quale nascono e si modificano i sistemi d’istruzione e per i diversi fattori – e, anzitutto, quello economico-produttivo – che rivestono un ruolo chiave nell’organizzazione dei sistemi d’istruzione.Dino Carina (1836-1872) is a Tuscan scholar of economics and of school policy; starting from the Sixties of the Nineteenth Century, he performs several journeys made in order to study the educational situations existing outside Italy (France, Belgium, Germany and England). He’s the author of several comparative education studies (e.g. Sulla istruzione primaria e industriale della Francia, dell'Inghilterra, del Belgio, 1861; Della istruzione primaria e industriale considerata nelle sue relazioni colla pubblica economia. Nuovi studi comparative, 1868; Dell’ozio in Italia, 1870). Nevertheless, Dino Carina is an author still little known and studied.
This paper considers his contribution to the process of development of comparative education studies in Italy in the years of the national unification. In particular, attention is focused on his interest in the socio-political and cultural environment in which education systems are born and modified and to the various factors – first of all the economic factor-productive – which play a key role in the organization of education systems
Dino Carina. Istruzione, lavoro, studi comparativi. II
No full textDino Carina (1836-1872), studioso toscano di economia e di politica scolastica, a partire dagli anni Sessanta dell’Ottocento compie diversi “viaggi pedagogici” in Francia, Belgio, Germania e Inghilterra. È autore di diversi lavori riguardanti l’educazione comparata: Sulla istruzione primaria e industriale della Francia, dell'Inghilterra, del Belgio (1861), Della istruzione primaria e industriale considerata nelle sue relazioni colla pubblica economia. Nuovi studi comparativi (1868), Dell’ozio in Italia (1870). Ciò nonostante, è un autore ancora poco conosciuto e studiato. In questo articolo si prende in considerazione il suo contributo al processo di sviluppo degli studi comparativi in educazione in Italia negli anni dell’unificazione nazionale. In particolare, si focalizza l’attenzione sul suo interesse per il contesto socio-politico-culturale nel quale nascono e si modificano i sistemi d’istruzione e per i diversi fattori – e, anzitutto, quello economico-produttivo – che rivestono un ruolo chiave nell’organizzazione dei sistemi d’istruzione.Dino Carina (1836-1872) is a Tuscan scholar of economics and of school policy; starting from the Sixties of the Nineteenth Century, he performs several journeys made in order to study the educational situations existing outside Italy (France, Belgium, Germany and England). He’s the author of several comparative education studies (e.g. Sulla istruzione primaria e industriale della Francia, dell'Inghilterra, del Belgio, 1861; Della istruzione primaria e industriale considerata nelle sue relazioni colla pubblica economia. Nuovi studi comparative, 1868; Dell’ozio in Italia, 1870). Nevertheless, Dino Carina is an author still little known and studied. This paper considers his contribution to the process of development of comparative education studies in Italy in the years of the national unification. In particular, attention is focused on his interest in the socio-political and cultural environment in which education systems are born and modified and to the various factors – first of all the economic factor-productive – which play a key role in the organization of education systems
Impact of a Static Magnetic Field on Early Osseointegration: A Pilot Study in Canines
No full textA static magnetic field generated by neodymium–iron–boron (NdFeB) magnets placed in the inner cavity of dental implants can enhance bone regeneration in rabbits. It is, however, unknown whether static magnetic fields support osseointegration in a canine model. We therefore determined the potential osteogenic effect of implants carrying NdFeB magnets inserted in the tibia of six adult canines in the early stages of osseointegration. Here, we report that after 15 days of healing, magnetic and regular implants showed a high variation with a median new bone-to-implant contact (nBIC) in the cortical (41.3% and 7.3%) and the medullary (28.6% and 44.8%) region, respectively. Consistently, the median new bone volume/tissue volume (nBV/TV) in the cortical (14.9% and 5.4%) and the medullary (22.2% and 22.4%) region were not significantly different. One week of healing only resulted in negligible bone formation. These findings suggest that considering the large variation and the pilot nature of this study, magnetic implants failed to support peri-implant bone formation in a canine model
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