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- Elgali, Ibrahim, et al.
(författare)
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Molecular and structural patterns of bone regeneration in surgically created defects containing bone substitutes
- 2014
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 35:10, s. 3229-3242
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Tidskriftsartikel (refereegranskat)abstract
- Several biomaterials have been introduced for bone augmentation. However, information is lacking about the mechanisms of bone regeneration and/or integration of these materials in the recipient bone. This study aimed to determine the molecular and structural events in bone defects after augmentation with synthetic tetrapod-shaped calcium phosphate (Tetrabone; TetraB) compared with natural deproteinized bovine bone (DBB). Defects were created in the epiphyses of rat femurs and filled with TetraB or DBB or left empty (Sham). After 3, 6, 14 and 28 d, samples were harvested for histology, histomorphometry, ultrastructure and gene expression analyses. At 3 d, higher expressions of bone formation (ALP and DC) and remodeling (CatK) genes were detected in TetraB compared with DBB and Sham. Downregulation of bone remodeling genes (TRAP and CatK) was detected in DBB as compared to Sham after 14 d. Histomorphometry at 6 and 14 d demonstrated greater bone contact with the granules in TetraB. At 28 d, a larger bone area per defect was found in TetraB. The present experiments show that a synthetic substitute, consisting of alpha-tricalcium and octacalcium phosphates, induces early osteogenic and osteoclastic activities and promotes bone formation in trabecular bone defects.
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| 2. |
- Suska, Felicia, 1974, et al.
(författare)
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Enhancement of CRF-PEEK osseointegration by plasma-sprayed hydroxyapatite: A rabbit model.
- 2014
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Ingår i: Journal of biomaterials applications. - : SAGE Publications. - 1530-8022 .- 0885-3282. ; 29:2, s. 234-242
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Tidskriftsartikel (refereegranskat)abstract
- Carbon-fibre-reinforced polyether ether ketone (CFR-PEEK) exhibits excellent biomechanical properties as it has an elastic modulus similar to bone. However, CFR-PEEK displays inferior biocompatibility compared with titanium alloy and coating techniques are therefore of interest in order to improve integration. In this paper, the early biological response to CFR-PEEK implants, with and without hydroxyapatite coating, was investigated. Furthermore, a hydroxyapatite-coated titanium alloy reference served as a clinically relevant control. The study was conducted in a rabbit model, both in femur trabecular bone as well as in tibia cortical bone. The results demonstrated that an hydroxyapatite coating significantly enhances the bone response to PEEK implants invivo. Moreover, in cortical bone, hydroxyapatite-coated PEEK implants induced superior bone response compared with hydroxyapatite-coated Ti ones. These results suggest that hydroxyapatite-coated CFR-PEEK is a suitable material for invivo implantation.
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| 7. |
- Bagdadi, Omar, 1974-, et al.
(författare)
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Dynamiska farthinder : en litteraturstudie
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- För att motverka de negativa konsekvenserna av solida farthinder, speciellt väggupp, har alternativa farthinder börjat komma, om än i begränsad omfattning. Ett alternativt farthinder kan vara utformat på olika sätt och vara antingen passivt dynamiskt eller aktivt dynamiskt. Passivt dynamiska farthinder är utformade så att tunga fordon kan passera nästan obemärkt med litet obehag medan vanliga bilister upplever liknande obehag som vid solida hinder och tvingas sänka hastigheten ordentligt. Aktivt dynamiska farthinder är däremot konstruerade så att det ska gå att hålla ett högt trafikflöde på en vägsträcka i jämn hastighet. Farthindret kräver inte att vare sig bilister eller tunga fordon saktar in under den tillåtna hastigheten för att passera obehindrat. De slutsatser som denna studie kan göra är att både passivt dynamiska och aktivt dynamiska farthinder är intressanta och kan till viss utsträckning ersätta och komplettera befintliga traditionella solida farthinder. Det är dock viktigt att påpeka att man bör vara tydlig med syftet och vilka effekter man vill åstadkomma i och med installationen av farthindret.
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| 8. |
- Bakker, D. C. E., et al.
(författare)
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An update to the surface ocean CO2 atlas (SOCAT version 2)
- 2014
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Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 6:1, s. 69-90
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Tidskriftsartikel (refereegranskat)abstract
- The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO 2 values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models. © Author(s) 2014. CC Attribution 3.0 License.
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| 9. |
- Bjermer, Leif, et al.
(författare)
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Current evidence and future research needs for FeNO measurement in respiratory diseases
- 2014
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 108:6, s. 830-841
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Forskningsöversikt (refereegranskat)abstract
- Although not yet widely implemented, fraction of exhaled nitric oxide (FeNO) has emerged in recent years as a potentially useful biomarker for the assessment of airway inflammation both in undiagnosed patients with non-specific respiratory symptoms and in those with established airway disease. Research to date essentially suggests that FeNO measurement facilitates the identification of patients exhibiting T-helper cell type 2 (Th2)-mediated airway inflammation, and effectively those in whom anti-inflammatory therapy, particularly inhaled corticosteroids (ICS), is beneficial. In some studies, FeNO-guided management of patients with established airway disease is associated with lower exacerbation rates, improvements in adherence to anti-inflammatory therapy, and the ability to predict risk of future exacerbations or decline in lung function. Despite these data, concerns regarding the applicability and utility of FeNO in clinical practice still remain. This article reviews the current evidence, both supportive and critical of FeNO measurement, in the diagnosis and management of asthma and other inflammatory airway diseases. It additionally provides suggestions regarding the practical application of FeNO measurement: how it could be integrated into routine clinical practice, how its utility could be assessed and its true value to both clinicians and patients could be established. Although some unanswered questions remain, current evidence suggests that FeNO is potentially a valuable tool for improving the personalised management of inflammatory airway diseases.
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| 10. |
- El-Bealy, Mostafa Omar
(författare)
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On the Formation of Macrosegregation and Interdendritic Cracks During Dendritic Solidification of Continuous Casting of Steel
- 2014
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Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science. - : Springer Science and Business Media LLC. - 1073-5615 .- 1543-1916. ; 45:3, s. 988-1017
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the current article is to elucidate the significant effects of macrosegregation distribution and its level on the different stages of interdendritic crack formation during dendritic solidification in continuously cast steel slabs. Couple formations of macrosegregation and interdendritic crack phenomena during dendritic solidification of peritectic carbon steels have been investigated by metallographic study of collected slab samples and by performing a set of mathematical analyses. The metallographic study involved plant trails to measure slab surface temperature of different secondary spray cooling conditions. Also, macro-microexaminations, measurements of dendrite arm spacing, macrosegregation analysis, and interdendritic distance between the dendrites of collected samples from plant trials have been performed. The experimental results show a fluctuation of carbon segregation with respect to distance from slab surface. These results also reveal that the interdendritic cracks vary with this fluctuation in various nano, macro, and microscales based on the cooling conditions. A mathematical model of heat transfer, solidification, structure evolution, interdendritic strain, macrosegregation, and elementary interdendritic area "EIA" has been developed. This model takes also into account the calculating of interdendritic distance between the dendrites "IDD" to evaluate the interdendritic crack width. The model predictions of different thermal and solidification phenomena show a good agreement with measurements. The results pointed out also that the coupled effect of interdendritic strain and macrosegregation phenomena and their distributions can be considered as the most important tools to evaluate the surface and internal interdendritic cracks in continuously cast steel slabs. The formation mechanisms of different types of interdendritic crack with interdendritic strain patterns and fluctuation of macrosegregation levels during various cooling zones have been explained, and the possible solutions to these problems have been discussed.
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