| 1. |
- Engström, Gunnar, et al.
(författare)
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The Swedish CArdioPulmonary BioImage Study : objectives and design
- 2015
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 278:6, s. 645-659
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Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.
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| 2. |
- Hansson, Malin, 1967, et al.
(författare)
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CCL28 is increased in human Helicobacter pylori induced gastritis and mediates recruitment of gastric IgA-secreting cells.
- 2008
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Ingår i: Infection and Immunity. - 0019-9567. ; 76:7, s. 3304-11
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Tidskriftsartikel (refereegranskat)abstract
- Human Helicobacter pylori infection gives rise to an active chronic gastritis and is a major risk factor for the development of duodenal ulcer disease and gastric adenocarcinoma. The infection is accompanied by a large accumulation of immunoglobulin A (IgA)-secreting cells in the gastric mucosa, and following mucosal immunization only H. pylori-infected volunteers mounted a B-cell response in the gastric mucosa. To identify the signals for recruitment of gastric IgA-secreting cells, we investigated the gastric production of CCL28 (mucosa-associated epithelial chemokine) and CCL25 (thymus-expressed chemokine) in H. pylori-infected and uninfected individuals and the potential of gastric B-cell populations to migrate toward these chemokines. Gastric tissue from H. pylori-infected individuals contained significantly more CCL28 protein and mRNA than that from uninfected individuals, while CCL25 levels remained unchanged. Chemokine-induced migration of gastric lamina propria lymphocytes isolated from patients undergoing gastric resection was then assessed using the Transwell system. IgA-secreting cells and IgA+ memory B cells from H. pylori-infected tissues migrated toward CCL28 but not CCL25, while the corresponding cells from uninfected patients did not. Furthermore, IgG-secreting cells from H. pylori-infected patients did not migrate to CCL28 but instead to CXCL12 (SDF-1). However, chemokine receptor expression did not correlate to the migratory pattern of the different B-cell populations. These studies are the first to show increased CCL28 production during gastrointestinal infection in humans and provide an explanation for the large influx of IgA-secreting cells to the gastric mucosa in H. pylori-infected individuals.
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| 3. |
- Holm, Sten, 1948, et al.
(författare)
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Reactive changes in the adolescent porcine spine with disc degeneration due to endplate injury
- 2007
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Ingår i: Vet Comp Orthop Traumatol. - 0932-0814. ; 20:1, s. 12-7
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Tidskriftsartikel (refereegranskat)abstract
- Degenerative and reactive structural alterations occurring after experimentally-induced disc degeneration were evaluated using a porcine model. A cranial perforation was made through the L4 vertebral endplate into the nucleus pulposus. Three months later, the lumbar intervertebral disc and adjacent vertebrae were dissected, fixed in formalin and further processed for histopathological analyses. The results showed that there were nucleus pulposus fragments, rather than a distinct border between the nucleus and annulus fibrosus. The central lamellae were distorted and delamination of the outer anterior layers was observed. Blood vessels emerged from the adjacent tissue, penetrated the annulus and branched into the residues of the nucleus. Nerve fibres accompanying the blood vessels could be recognized in the disc within the connective scar tissue. The epiphyseal cartilage plates in the vertebrae were hypertrophic in several areas and there was bone formation directed towards the centre of the vertebral body and the disc. Hypertrophic hyaline cartilage, newly formed bone and scar tissue filled the injury canal. A slight chronic inflammatory reaction was evident along vascular buds. The reactive changes dominated over the degenerated features in the operated disc. Physiological loading enhanced the infiltration of various tissue types characterizing immature cartilage formation. Prominent neovascularisation of the central parts of the disc is likely to be of key importance in turning the degenerative features of the remaining tissue into reactive healthy structures.
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| 4. |
- Couceiro, José, 1983-, et al.
(författare)
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CT scanning of capillary phenomena in bio-based materials
- 2017
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Ingår i: Pro Ligno. - Romania : Pro Ligno Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 181-187
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Tidskriftsartikel (refereegranskat)abstract
- X-ray computed tomography (CT) is a powerful tool for the non-destructive study of dynamic moisture processes in wood and other bio-based materials. In the CT facilities at Luleå University of Technology, it is possible to study wood-moisture relations such as water absorption, drying and related material deformation under a temperature- and humidity-controlled environment.An increase in the use of bio-based materials in building construction has led to an increased interest in capillary phenomena in these materials, because of an increasing number of moisture-related damage in timber and hybrid-timber buildings. This article shows some examples of how different bio-materials used in construction interact with liquid water over time. The overall purpose has been to develop the CT technique as a powerful tool for the determination and visualization of capillary flow that can be a base for modelling and an increased understanding of moisture flow in new bio-based building materials.Early-stage observation of the behaviour of different traditional and new bio-based building materials shows that CT scanning, combined with image processing, has a high potential to be used in performing non-destructive and non-contact tests that can help to increase the knowledge of water-material interactions and develop building materials with an optimized performance.
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| 5. |
- Couceiro, José, 1983-, et al.
(författare)
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CT-scanning of the drying process of Eucalyptus nitens.
- 2018
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Ingår i: Proceedings of 21st International Drying Symposium.. - Valencia : Editorial Universitat Politècnica de València. - 9788490486887 ; , s. 1269-1276
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Konferensbidrag (refereegranskat)abstract
- The drying of Eucalyptus nitens is a troublesome process as the species is extremely prone to drying defects. This paper reports ongoing research toimprove the understanding of surface checking and cell collapse in Chilean grown Eucalyptus nitens during drying. Computed tomography (CT) scanning was used as a powerful tool for studying the internal changes in the wood-material during the drying process. Different levels of temperatures have been tested with the same equilibrium moisture content (EMC) conditions and low air velocity. The results confirm that a low drying temperature and a low air velocity, which results in a slow rate of drying, reduce internal cell collapse and surface checking .
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| 6. |
- Couceiro, José, 1983-, et al.
(författare)
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CT-studies during the Conditioning phase of the Wood Drying Process
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Computed tomography (CT) during drying of sawn timber is an excellent non-destructivetechnique to study the moisture flux as a function of drying time. In this study, a climatechamber combined with a medical CT- scanner has been used for non-destructive studies ofdensity changes in sawn timber during drying and conditioning.Green sawn timber contains large amounts of water and has to be dried before it can befurther processed and used in various building applications. The most common dryingmethod is convective air-circulation drying in large industrial kilns, where the relativehumidity (RH) of the hot circulating air is gradually reduced until the timber reaches thetarget moisture content (MC).Drying of sawn timber is driven by the existence of a difference in MC between the coreand the surface, so that moisture moves from the wet inner region towards the drier outerregion. During the early capillary stages of drying, the drying rate is high while, at the laterstages when all liquid water has evaporated, the drying rate is slow and diffusioncontrolled.At the end of the drying process, the timber surface is always drier than its core.In addition to this moisture gradient, internal stresses develop within the cross section withcompression stresses in the timber surface and tension in the inner regions. To avoidunwanted distortions, both these stresses and the moisture gradient, need to be eliminatedbefore the timber is further processed. This is achieved in a final conditioning stage withinthe drying process by moistening the circulating air through steaming or water spraying.The aim of the present work was to optimize the conditioning stage by developing amethod for studying of moisture gradients, deformations and internal and externaldimensional changes in sawn timber during the conditioning phase by using a CT-scannercombined with a drying unit for in-situ measurements of moisture flow.The results show that it is possible to detect the moisture gradient between the surface andcore of the timber with satisfactory reliability, but not the internal and external dimensionalchanges. However, this method creates a potential for increasing the knowledge andunderstanding of the conditioning phase and makes it possible to optimize and develop thisstep in the drying process to improve the yield and ensure a higher quality of the sawntimber.
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| 7. |
- Couceiro, José, 1983-, et al.
(författare)
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Dual-Energy X-Ray Absorptiometry for Measuring Moisture Content in Wood : Is It Possible?
- 2019
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Ingår i: Proceedings. - : United States Department of Agriculture. ; , s. 292-292
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Medical computer tomography (CT) uses dual-energy x-ray absorptiometry (DXA) for basis material differentiation. DXA is based on the different interactions between x-ray photons and the scanned material based on the energy of the x ray, the effective atomic number of the material components, and their electron density. Considering wood and water as the only components of a wood specimen at a given moisture content (MC), DXA has been suggested for quantification of the wood-water proportion and thus for the determination of MC. Such an approach can provide great improvements and advantages in the use of CT technology in the sawmill industry, for example, detection of fresh knots in sapwood and optimization of timber drying. However, the approach in wood science is recent and still presents doubts. This study tries to clarify the possibilities of dual-energy CT for estimation of moisture in wood through the approach of the ratio method, which has been used as the theoretical basis for establishing the feasibility of the DXA in wood science and which is often used for differentiation between components of a scanned material. Two-dimensional x-ray measurements were confronted with theoretical calculations. The theoretical calculations show that the attenuation of water and wood at different acceleration voltages differs enough to apply the ratio method, but the practical experiments cannot prove it. The authors suggest that the inhomogeneity in wood introduces large errors that cause misleading results. Also, the equipment providing measurements of photon count could present different results.
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| 8. |
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| 9. |
- Couceiro, José, 1983-, et al.
(författare)
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In situ CT-scanning for detection of internal checking and cell collapse during drying of hardwood species
- 2016
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Ingår i: The 7th European Conference on Hardwood, Eco-efficient resource wood with special focus on hardwoods. - Sopron : University of West Hungary. - 9789633342916 ; , s. 58-59
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Konferensbidrag (refereegranskat)abstract
- During the drying of sawn timber, hydrostatic tension forces within the cell may exceed the compressive strength perpendicular to the grain of the thin cell wall and the cell then collapses. This phenomenon is common in hardwoods such as Sequoia sempervirens, Thuja plicata, Tsuga heterophylla, Juglans nigraand many species of eucalyptus and oak. Usually, this leads to severe surface deformation, and both surface and internal checking(honeycombing) may occur. The quality of the final product is lowered by these cracks and deformations. The aim of this study was to investigate, by CT-scanning samples throughout the drying process, whether it is possible to detect when and how cracking and deformation occurs and develops in specimens of Eucalyptus nitens. Based on this knowledge, better drying schedules can be developed to improve the yield and ensure a higher quality of the sawn timber. Three specimens, one specimen in each drying run, of Eucalyptus nitens were used for the tests. Their cross-sectional dimensions, prior to drying, were 105x23 mm2 and their length was 70 cm. A specially designed laboratory drying kiln that fits within the gantry of a Siemens Somatom Emotion medical CT-scanner was used (Fig. 1). With this equipment, it is possible to scan the inside of the kiln without interrupting the drying process.
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| 10. |
- Couceiro, José, 1983-, et al.
(författare)
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Industrial CT scanning in wood research
- 2022
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Ingår i: Proceedings: 22nd International Nondestructive Testing and Evaluation of Wood Symposium. - Madison (WI), USA : United States Department of Agriculture. ; , s. 17-17
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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