54 resultados para BONE BIO-OSS


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21 x 27 cm

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kuv., 22 x 30 cm

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Due to technical restrictions of the database system the title of the thesis does not show corretly on this page. Numbers in the title are in superscript. Please see the PDF-file for correct title. ---- Osteomyelitis is a progressive inflammatory disease of bone and bone marrow that results in bone destruction due to an infective microorganism, most frequently Staphylococcus aureus. Orthopaedic concern relates to the need for reconstructive and trauma-related surgical procedures in the fast grow¬ing population of fragile, aged patients, who have an increased susceptibility to surgical site infections. Depending on the type of osteomyelitis, infection may be acute or a slowly progressing, low-grade infection. Peri-implant infections lead to implant loosening. The emerging antibiotic resistance of com¬mon pathogens further complicates the situation. With current imaging methods, significant limitations exist in the diagnosing of osteomyelitis and implant-related infections. Positron emission tomography (PET) with a glucose analogue, 18F-fluoro¬deoxyglucose (18F-FDG), seems to facilitate a more accurate diagnosis of chronic osteomyelitis. The method is based on the increased glucose consumption of activated inflammatory cells. Unfortunately, 18F-FDG accumulates also in sterile inflammation regions and causes false-positive findings, for exam¬ple, due to post-operative healing processes. Therefore, there is a clinical need for new, more infection-specific tracers. In addition, it is still unknown why 18F-FDG PET imaging is less accurate in the detec¬tion of periprosthetic joint infections, most frequently due to Staphylococcus epidermidis. This doctoral thesis focused on testing novel PET tracers (68Ga-chloride and 68Ga-DOTAVAP-P1) for early detections of bone infections and evaluated the role of pathogen-related factors in the appli¬cations of 18F-FDG PET in the diagnostics of bone infections. For preclinical models of S. epidermidis and S. aureus bone/implant infections, the significance of the causative pathogen was studied with respect to 18F-FDG uptake. In a retrospective analysis of patients with confirmed bone infections, the significance of the presence or absence of positive bacterial cultures on 18F-FDG uptake was evalu¬ated. 18F-FDG and 68Ga-chloride resulted in a similar uptake in S. aureus osteomyelitic bones. However, 68Ga-chloride did not show uptake in healing bones, and therefore it may be a more-specific tracer in the early post-operative or post-traumatic phase. 68Ga-DOTAVAP-P1, a novel synthetic peptide bind¬ing to vascular adhesion protein 1 (VAP-1), was able to detect the phase of inflammation in healing bones, but the uptake of the tracer was elevated also in osteomyelitis. Low-grade peri-implant infec¬tions due to S. epidermidis were characterized by a low uptake of 18F-FDG, which reflects the virulence of the causative pathogen and the degree of leukocyte infiltration. In the clinical study, no relationship was found between the level of 18F-FDG uptake and the presence of positive or negative bacterial cul¬tures. Thus 18F-FDG PET may help to confirm metabolically active infection process in patients with culture-negative, histologically confirmed, low-grade osteomyelitis.

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The main objective of the present study was to verify the approach on starch-gelatin blending for the paperboard coating formulations with enhanced barrier and mechanical properties. Based on that, another objective was to find out, how the approach will function with wood-based polysaccharides (CMC, EHEC and HPC) by analyzing their barrier properties and convertibility. The last objective was to find out, if pigments can be used in the composition of polysaccharide-protein blends without causing any negative effect on stated properties. The whole process chain of the barrier coating development was studied in the research. The methodology applied included pilot-scale coating and converting trials for the evaluation of mechanical properties of obtained coatings, namely their exposure to cracking with the loss of barrier properties. The results obtained indicated that the combination of starch with gelatin, in fact, improves the grease barrier properties and flexibility of starch-based coatings, thereby confirming the offered approach. The similar results were obtained for CMC, exhibited elevated barrier properties and surface coverage, proving that the approach also functions with wood-based polysaccharides. The introduction of equal amounts of talc gave various effects at different gelatin dosages on barrier properties of wood-based polysaccharides. Mainly, the elevation of grease barrier properties was observed. The convertibility of talc-filled coatings was not sufficient.

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Cranial bone reconstructions are necessary for correcting large skull bone defects due to trauma, tumors, infections and craniotomies. Traditional synthetic implant materials include solid or mesh titanium, various plastics and ceramics. Recently, biostable glass-fiber reinforced composites (FRC), which are based on bifunctional methacrylate resin, were introduced as novel implant solution. FRCs were originally developed and clinically used in dental applications. As a result of further in vitro and in vivo testing, these composites were also approved for clinical use in cranial surgery. To date, reconstructions of large bone defects were performed in 35 patients. This thesis is dedicated to the development of a novel FRC-based implant for cranial reconstructions. The proposed multi-component implant consists of three main parts: (i) porous FRC structure; (ii) bioactive glass granules embedded between FRC layers and (iii) a silver-polysaccharide nanocomposite coating. The porosity of the FRC structure should allow bone ingrowth. Bioactive glass as an osteopromotive material is expected to stimulate the formation of new bone. The polysaccharide coating is expected to prevent bacterial colonization of the implant. The FRC implants developed in this study are based on the porous network of randomly-oriented E-glass fibers bound together by non-resorbable photopolymerizable methacrylate resin. These structures had a total porosity of 10–70 volume %, of which > 70% were open pores. The pore sizes > 100 μm were in the biologically-relevant range (50-400 μm), which is essential for vascularization and bone ingrowth. Bone ingrowth into these structures was simulated by imbedding of porous FRC specimens in gypsum. Results of push-out tests indicated the increase in the shear strength and fracture toughness of the interface with the increase in the total porosity of FRC specimens. The osteopromotive effect of bioactive glass is based on its dissolution in the physiological environment. Here, calcium and phosphate ions, released from the glass, precipitated on the glass surface and its proximity (the FRC) and formed bone-like apatite. The biomineralization of the FRC structure, due to the bioactive glass reactions, was studied in Simulated Body Fluid (SBF) in static and dynamic conditions. An antimicrobial, non-cytotoxic polysaccharide coating, containing silver nanoparticles, was obtained through strong electrostatic interactions with the surface of FRC. In in vitro conditions the lactose-modified chitosan (chitlac) coating showed no signs of degradation within seven days of exposure to lysozyme or one day to hydrogen peroxide (H2O2). The antimicrobial efficacy of the coating was tested against Staphylococcus aureus and Pseudomonas aeruginosa. The contact-active coating had an excellent short time antimicrobial effect. The coating neither affected the initial adhesion of microorganisms to the implant surface nor the biofilm formation after 24 h and 72 h of incubation. Silver ions released to the aqueous environment led to a reduction of bacterial growth in the culture medium.

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Skeletal tissue is constantly remodeled in a process where osteoclasts resorb old bone and osteoblasts form new bone. Balance in bone remodeling is related to age, gender and genetic factors, but also many skeletal diseases, such as osteoporosis and cancer-induced bone metastasis, cause imbalance in bone turnover and lead to decreased bone mass and increased fracture risk. Biochemical markers of bone turnover are surrogates for bone metabolism and may be used as indicators of the balance between bone resorption and formation. They are released during the remodeling process and can be conveniently and reliably measured from blood or urine by immunoassays. Most commonly used bone formation markers include N-terminal propeptides of type I collagen (PINP) and osteocalcin, whereas tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) and C-terminal cross-linked telopeptide of type I collagen (CTX) are common resorption markers. Of these, PINP has been, until recently, the only marker not commercially available for preclinical use. To date, widespread use of bone markers is still limited due to their unclear biological significance, variability, and insufficient evidence of their prognostic value to reflect long term changes. In this study, the feasibility of bone markers as predictors of drug efficacy in preclinical osteoporosis models was elucidated. A non-radioactive PINP immunoassay for preclinical use was characterized and validated. The levels of PINP, N-terminal mid-fragment of osteocalcin, TRACP 5b and CTX were studied in preclinical osteoporosis models and the results were compared with the results obtained by traditional analysis methods such as histology, densitometry and microscopy. Changes in all bone markers at early timepoints correlated strongly with the changes observed in bone mass and bone quality parameters at the end of the study. TRACP 5b correlated strongly with the osteoclast number and CTX correlated with the osteoclast activity in both in vitro and in vivo studies. The concept “resorption index” was applied to the relation of CTX/TRACP 5b to describe the mean osteoclast activity. The index showed more substantial changes than either of the markers alone in the preclinical osteoporosis models used in this study. PINP was strongly associated with bone formation whereas osteocalcin was associated with both bone formation and resorption. These results provide novel insight into the feasibility of PINP, osteocalcin, TRACP 5b and CTX as predictors of drug efficacy in preclinical osteoporosis models. The results support clinical findings which indicate that short-term changes of these markers reflect long-term responses in bone mass and quality. Furthermore, this information may be useful when considering cost-efficient and clinically predictive drug screening and development assays for mining new drug candidates for skeletal diseases.

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Varsinais-Suomen ELY-keskus teettää säännöllisesti maakunnan valikoiduille toimialoille työvoiman ja koulutuksen tarvetutkimuksia (TKTT). Tähän raporttiin on koottu bio- ja terveysalan TKTT-prosessin kaikki osiot: toimialan tilastotiedot, yrityshaastattelut syksyltä 2009, 2.3.2010 järjestetyn asiantuntijaraadin yhteenveto ja Delfoi-kierroksen tulokset. Varsinais-Suomi on kotimaassa lääketieteellisen bioalan kärkeä ja kansainvälistä huippua tietyillä tutkimusalueilla. Tässä työssä toimiala luokitellaan määritelmällä ”bioja terveysala”, johon kuuluvat lääkkeiden kehitys- ja valmistus, diagnostiikka, bioalan palvelut ja biomateriaalit. Toimialalla oli yrityksiä vuonna 2008 tehdyn kartoituksen perusteella noin 100, liikevaihdon ollessa yhteensä noin 522 miljoonaa €. Ala työllisti suoraan yli 2500 henkilöä, jonka lisäksi on huomioitava merkittävä alihankintaverkosto. Bio- ja terveysalan yrityskenttä jakautuu useisiin pienyrityksiin ja muutamiin suuryrityksiin, jotka työllistävät pääosan alan henkilöstöstä. Bioalan kehitystä koordinoi Turku Science Parkin BioTurku, joka on luonut vuonna 2009 uusimman strategian kasvuodotusten toteuttamiseksi. Viime vuosina Varsinais-Suomeen on syntynyt erityisesti biopalvelu- ja liiketoiminnankehitysyrityksiä. Alan koulutusta tarjotaan runsaasti, pääasiassa yliopistoissa ja ammattikorkeakoulussa. Aloituspaikkoja vuonna 2009 oli Turussa yhteensä 174. TKTT-haastattelut tehtiin yrityksissä loka-marraskuussa 2009: niissä haastateltiin 24 toimijaa, jotka työllistivät kaikkiaan 1849 henkilöä. Muutaman suuren yrityksen ansiosta määrä vastaa noin 70 % alan koko työvoimasta, mutta kattaa myös kaikki toimialamäärittelyssä esitetyt alaluokat Varsinais-Suomessa. Tutkimuskohteista pkyrityksiin lukeutui 80 %, mutta kokonaishenkilöstöstä 86 % työskenteli kolmen suurimman yrityksen palveluksessa. Yritysten näkymät vuonna 2009 olivat tilastollisesti optimistisia taloustilanteeseen nähden, ja lama on selvästikin taittumassa alalla. Vuoden kuluessa työllistävyyskehitys on kuitenkin vielä varovaista. Henkilöstön nettomäärä haastatelluissa yrityksissä lisääntyy syksyyn 2010 mennessä noin 11 henkilöllä. Suurin kasvu (20 %) on alle 10 henkeä työllistävissä mikroyrityksissä, ja työvoiman vähenemä koostuu pääasiassa suurempien yritysten eläkkeelle siirtyvistä työntekijöistä. Bio- ja terveysalalla on moninaisia tutkimukseen ja tuotantoon liittyviä toimenkuvia. Yleisimpiä ammattinimikkeitä haastatelluissa yrityksissä olivat kemisti, laborantti, insinööri ja tuotantotyöntekijä. Diagnostiikka-alan alihankintatöissä tarvitaan elektroniikka-asentajia. Henkilöstön ikärakenne painottuu 25-39-vuotiaisiin, joita on yli 40 % työvoimasta. Nuoria alle 24-vuotiaita työntekijöitä on erittäin vähän, mutta toisaalta vain 2 % työntekijöistä on eläköitymässä kahden vuoden kuluessa. Haastattelutulosten mukaan syksyllä 2009 noin puolessa yrityksistä elettiin nousukauden alkua, ja lamaan itsensä sijoitti viidennes. Syksyllä 2010 yrityksistä jo 95 % uskoo olevansa suhdannekäyrän positiivisella puolella, mutta kasvupotentiaalia on vielä huomattavasti. Haastatteluhetkellä työvoiman käyttöaste oli pääosin sopiva ja vain neljällä yrityksellä alhainen.

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Närings-, trafik- och miljöcentralen (ELY-centralen) i Egentliga Finland är en mångsidig och branschövergripande utvecklings- och servicecentral som grundades i och med regionförvaltningsreformen. Vårt mål är att stärka en hållbar välfärd i Egentliga Finland och Satakunta. Utgångspunkten för vår verksamhet är ett nätverksbaserat samarbete med andra aktörer i regionen. Den bästa genomslagskraften och de bästa målen uppnår man genom gott samarbete och genom att rikta och sammanjämka resurser på ett effektivt sätt.

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Bio-ethanol has been used as a fuel additive in modern society aimed at reducing CO2-emissions and dependence on oil. However, ethanol is unsuitable as fuel supplement in higher proportions due to its physico-chemical properties. One option to counteract the negative effects is to upgrade ethanol in a continuous fixed bed reactor to more valuable C4 products such as 1-butanol providing chemical similarity with traditional gasoline components. Bio-ethanol based valorization products also have other end-uses than just fuel additives. E.g. 1-butanol and ethyl acetate are well characterised industrial solvents and platform chemicals providing greener alternatives. The modern approach is to apply heterogeneous catalysts in the investigated reactions. The research was concentrated on aluminium oxide (Al2O3) and zeolites that were used as catalysts and catalyst supports. The metals supported (Cu, Ni, Co) gave very different product profiles and, thus, a profound view of different catalyst preparation methods and characterisation techniques was necessary. Additionally, acidity and basicity of the catalyst surface have an important role in determining the product profile. It was observed that ordinary determination of acid strength was not enough to explain all the phenomena e.g. the reaction mechanism. One of the main findings of the thesis is based on the catalytically active site which originates from crystallite structure. As a consequence, the overall evaluation of different by-products and intermediates was carried out by combining the information. Further kinetic analysis was carried out on metal (Cu, Ni, Co) supported self-prepared alumina catalysts. The thesis gives information for further catalyst developments aimed to scale-up towards industrially feasible operations.

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Arbetet undersöker uttryck för konservativ, klassisk och bekännelsetrogen kristen tro inom Svenska kyrkan av idag och vill erbjuda ny kunskap om den konservativa trosövertygelsens psykologiska dynamik. Ett publicerat textmaterial skrivet av tre präster inom Svenska kyrkan analyseras med en hermeneutisk metod. Arbetet hör till den etablerade traditionen av kvalitativa religionspsykologiska studier i Skandinavien. Analysen av tankestrukturerna i texterna visat på ett specifikt förhållningssätt till kunskap på personligt viktiga områden, t ex trosfrågeområdet. Med hjälp av teorin om ovisshetsorientering har jag slutit mig till ett visshetsorienterat förhållningssätt till kunskap: ny kunskap undviks när det gäller trosfrågor. Jag ser istället en tydlig strävan efter att få den redan kända kunskapen och det entydiga bekräftat. Jag har också undersökt var denna visshetsorienterade inställning till kunskap kunde tänkas ha sitt ursprung. Det tycks föreligga en bristande tillit i relation till världen och till medmänniskorna. Texterna förmedlar en uttalad hotupplevelse. Med hjälp av anknytningsteorin, som vill beskriva något av samspelet mellan den första vårdnadsgivaren och barnet, har jag kunna dra några preliminära slutsatser. Det kunde finnas en s k otrygg avvisande anknytningsstil i bakgrunden. Det betyder förenklat att den första vårdnadsgivaren upplevdes som på något sätt mindre tillgänglig, inte så förutsägbar eller avvisande. Konservativ kristen tro betonar läran om den dubbla utgången - en föreställning om att bara de människor som har den rätta tron kan räkna med ett evigt liv, medan de andra döms till helvetet och därmed upphör att existera. Texterna uttrycker tydligt detta synsätt. Det finns spår av en uttalad rädsla för att inte vinna det eviga livet. Istället uttrycks en fruktan för att gå evigt förlorad. Jag ser det som ett tecken på att insikten om människans dödlighet har en mycket specifik emotionell laddning hos de konservativt troende. Frågan om den personliga eviga saligheten ses ända fram till dödsögonblicket som oavgjord. Insikten om vår dödlighet kallar den tredje av de av mig använda teorierna för dödens terror. På en djuppsykologisk nivå tycks denna ångest för att hjälpligt kunna hanteras bli projicerad in i det öde som väntar den icke troende. Därmed får den konservativa trosläran näring från ett omedvetet känsloladdat konfliktområde.

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Työssä tarkastellaan bio- ja maakaasun käyttöä Suomen tieliikenteen polttoaineena. Työn lähtökohtana on selvittää kaasukäyttöisten ajoneuvojen käytön kannattavuutta Suomessa ja niiden etuja muihin polttoaineisiin nähden. Tutkielmassa perehdytään erityisesti biokaasun käyttöön fossiilisten polttoaineiden korvaajana ja mitä vaatimuksia sen käytön lisääminen edellyttää. Työssä perehdytään kaasujen tuotantomenetelmiin, jakeluun, taloudelliseen kannattavuuteen, ympäristöystävällisyyteen ja tulevaisuuden näkymiin.

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Non-metallic implants made of bioresorbable or biostable synthetic polymers are attractive options in many surgical procedures, ranging from bioresorbable suture anchors of arthroscopic surgery to reconstructive skull implants made of biostable fiber-reinforced composites. Among other benefits, non-metallic implants produce less interference in imaging. Bioresorbable polymer implants may be true multifunctional, serving as osteoconductive scaffolds and as matrices for simultaneous delivery of bone enhancement agents. As a major advantage for loading conditions, mechanical properties of biostable fiber-reinforced composites can be matched with those of the bone. Unsolved problems of these biomaterials are related to the risk of staphylococcal biofilm infections and to the low osteoconductivity of contemporary bioresorbable composite implants. This thesis was focused on the research and development of a multifunctional implant model with enhanced osteoconductivity and low susceptibility to infection. In addition, the experimental models for assessment, diagnostics and prophylaxis of biomaterial-related infections were established. The first experiment (Study I) established an in vitro method for simultaneous evaluation of calcium phosphate and biofilm formation on bisphenol-Aglycidyldimethacrylate and triethylenglycoldimethacrylate (BisGMA-TEGDMA) thermosets with different content of bioactive glass 45S5. The second experiment (Study II) showed no significant difference in osteointegration of nanostructured and microsized polylactide-co-glycolide/β-tricalcium phosphate (PLGA /β-TCP) composites in a minipig model. The third experiment (Study III) demonstrated that positron emission tomography (PET) imaging with the novel 68Ga labelled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) CD33 related sialic-acid immunoglobulin like lectins (Siglec-9) tracer was able to detect inflammatory response to S. epidermidis and S. aureus peri-implant infections in an intraosseous polytetrafluoroethylene catheter model. In the fourth experiment (Study IV), BisGMATEGDMA thermosets coated with lactose-modified chitosan (Chitlac) and silver nanoparticles exhibited antibacterial activity against S. aureus and P. aeruginosa strains in an in vitro biofilm model and showed in vivo biocompatibility in a minipig model. In the last experiment (Study V), a selective androgen modulator (SARM) released from a poly(lactide)-co-ε-caprolactone (PLCL) polymer matrix failed to produce a dose-dependent enhancement of peri-implant osteogenesis in a bone marrow ablation model.

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The objective of this thesis was to identify the determinants of bone strength and predictors of hip fracture in representative samples of Finnish adults. A secondary objective was to construct a simple multifactorial model for hip fracture prediction over a 10-year follow-up period. The study was based on the Health 2000 Survey conducted during 2000 to 2001 (men and women aged 30 years or over, n=6 035) and the Mini-Finland Health Survey conducted during 1978 to 1980 (women aged 45 years or over, n=2 039). Study subjects participated in health interviews and comprehensive health examination. In the Health 2000 Survey, bone strength was assessed by means of calcaneal quantitative ultrasound (QUS). The follow-up information about hip fractures was drawn from the National Hospital Discharge Register. In this study, age, weight, height, serum 25-hydroxyvitamin D (S-25(OH)D), physical activity, smoking and alcohol consumption as well as menopause and eventual HRT in women were found to be associated with calcaneal broadband ultrasound attenuation (BUA) and speed of sound (SOS). Parity was associated with a decreased risk of hip fracture in postmenopausal women. Age, height, weight or waist circumference, quantitative ultrasound index (QUI), S-25(OH)D and fall-related factors, such as maximal walking speed, Parkinson’s disease, and the number of prescribed CNS active medication were significant independent predictors of hip fracture. At the population level, the incremental value of QUS appeared to be minor in hip fracture prediction when the fall-related risk factors were taken into account. A simple multifactorial model for hip fracture prediction presented in this study was based on readily available factors (age, gender, height, waist circumference, and fallrelated factors). Prospective studies are needed to test this model in patient-based study populations.

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The thesis aims to build a coherent view and understanding of the innovation process and organizational technology adoption in Finnish bio-economy companies with a focus on innovations of a disruptive nature. Disruptive innovations are exceptional hence in order to create generalizations and a unified view of the subject the perspective is also on less radical innovations. Other interests of the thesis are how ideas are discovered and generated and how the nature of the innovation and size of the company affect the technology adoption and innovation process. The data was collected by interviewing six small and six large Finnish bio-economy companies. The results suggest companies regardless of size consider innovation as a core asset in the competitive markets. Organizations want to be considered innovators and early adopters yet these qualities are limited by certain, mainly resource-based factors. In addition the industry, scalability and Finland’s geographical location when seeking funding provide certain challenges. The innovation process may be considered relatively similar whether the idea or technology stems from an internal or external source suggesting the technology adoption process can in fact be linked to the innovation process theories. Thus the thesis introduces a new theoretical model which based on the results of the study and the theories of technology adoption and innovation process aims on characterizing how ideas and technology from both external and internal sources generate into innovations. The innovation process is in large bio-economy companies most often similar to or a modified version of the stage-gate model, while small companies generally have less structured processes. Nevertheless the more disruptive the innovation, the less it fits in the structured processes. This implies disruptive innovation cannot be put in a certain mould but it is rather processed case-by-case.