| 1. |
- Galli, Silvia, et al.
(författare)
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Evaluation of the degradation behavior of resorbable metal implants for in vivo osteosynthesis by synchrotron radiation based x-ray tomography and histology
- 2016
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Ingår i: Developments in X-Ray Tomography X. - : SPIE - International Society for Optical Engineering.
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Konferensbidrag (refereegranskat)abstract
- Magnesium(Mg)-alloys are promising candidates as temporary implants for orthopedic and cranio-facial applications. They can sustain tissues during healing, thanks to favorable mechanical properties, and then they slowly degrade into biocompatible products, avoiding the need of a second surgery for implant removal. They have the potential to benefit a vast number of patients, especially children and elderly patients. However, to be able to tailor their degradation to match the speed of tissue regeneration it is crucial to understand how they actually degrade in the living organism. We utilized high-resolution synchrotron-based tomography at the beamline P05 operated by HZG at the storage ring PETRA III at DESY to study the degradation of 3 novel Mg-alloys in rat bone and the consequent bone response. On three-dimensional reconstructions of the bone-implant explants we were able to follow the dynamic transformation that the materials underwent at different healing times and on the basis of absorption coefficients we could distinguish and quantify the amount of remaining implants, the corrosion layers and the new bone. This was a great advantage compared to laboratory CT, for which the limitation in contrast and in resolution made impossible to discriminate between original alloy, degradation products and bone, leading to inaccurate determination of the materials degradation rates. The same samples imaged by tomography were used for non-decalcified histology. The combination of histological and tomographical images provided new insight on the nature of the bone-to-implant interface and of the degradation products, which appeared to have great similarities to the host bone.
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| 2. |
- Williamson, Alice, et al.
(författare)
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Genome-wide association study and functional characterization identifies candidate genes for insulin-stimulated glucose uptake
- 2023
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Ingår i: Nature Genetics. - : Springer Nature. - 1061-4036 .- 1546-1718. ; 55:6, s. 973-983
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Tidskriftsartikel (refereegranskat)abstract
- Distinct tissue-specific mechanisms mediate insulin action in fasting and postprandial states. Previous genetic studies have largely focused on insulin resistance in the fasting state, where hepatic insulin action dominates. Here we studied genetic variants influencing insulin levels measured 2 h after a glucose challenge in >55,000 participants from three ancestry groups. We identified ten new loci (P < 5 × 10-8) not previously associated with postchallenge insulin resistance, eight of which were shown to share their genetic architecture with type 2 diabetes in colocalization analyses. We investigated candidate genes at a subset of associated loci in cultured cells and identified nine candidate genes newly implicated in the expression or trafficking of GLUT4, the key glucose transporter in postprandial glucose uptake in muscle and fat. By focusing on postprandial insulin resistance, we highlighted the mechanisms of action at type 2 diabetes loci that are not adequately captured by studies of fasting glycemic traits.
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