| 1. |
- Bachinger, Angelika, et al.
(author)
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Stiffness-modifiable composite for pedestrian protection
- 2014
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In: 16th European Conference on Composite Materials, ECCM 2014. - : European Conference on Composite Materials, ECCM. - 9780000000002
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Conference paper (peer-reviewed)abstract
- A novel functional material allowing stiffness-reduction upon external stimulation was developed. Implementation of such technology in the design of a car front has high potential to result in increased protection of vulnerable road users (VRUs). The composite material is obtained by coating carbon fibres with a thermoplastic polymer in a continuous process, followed by infusion with an epoxy resin. The process is scalable for industrial use. The coating process was optimized regarding coating efficiency, energy consumption, risks involved for operating personnel and environment, and tailored to gain the optimal coating thickness obtained from numerical calculations. A drastic decrease in transversal stiffness could be detected for the composite material by dynamic mechanical thermal analysis (DMTA), when the temperature was increased above the glass transition temperature of the thermoplastic interphase. The ability of the material to achieve such temperature and associated reduction in stiffness by the application of current was verified using a special 3-point bending setup developed for this task.
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| 2. |
- Fredriksson, Ann-Charlotte, et al.
(author)
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Patients' perception of music versus ordinary sound in a postanaesthesia care unit : a randomised crossover trial
- 2009
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In: Intensive & Critical Care Nursing. - : Elsevier BV. - 0964-3397 .- 1532-4036. ; 25:4, s. 208-213
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Journal article (peer-reviewed)abstract
- We performed an experimental single-blind crossover design study in a postanaesthesia care unit (PACU): (i) to test the hypothesis that patients will experience a higher degree of wellbeing if they listen to music compared to ordinary PACU sounds during their early postoperative care, (ii) to determine if there is a difference over time, and (iii) to evaluate the importance of the acoustic environment and whether patients prefer listening to music during their stay. Two groups received a three-phase intervention: one group (n=23) experienced music-ordinary sound-music and the second group (n=21) experienced ordinary sound-music-ordinary sound. Each period lasted 30 min, and after each period the patients assessed their experience of the sound. The results demonstrated a significant difference (p<0.001) between groups in the proportions of patients reporting that the acoustic environment was of great importance for their wellbeing during the three-phase intervention, and most participants (n=36 versus n=8) noticed that they were exposed to different sounds during the PACU period. The results also revealed that most participants (n=32) preferred listening to music versus listening to ordinary sound (n=3) while in the PACU (p<0.001). These findings promote use of listening to music to establish a healing environment for patients in a postanaesthesia care unit.
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| 3. |
- Bachinger, Angelika, et al.
(author)
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Materials with variable stiffness
- 2015
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In: ICCM International Conferences on Composite Materials. - : International Committee on Composite Materials.
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Conference paper (peer-reviewed)abstract
- In this study different concepts to attain a material that can reduce its stiffness upon external stimulation were evaluated regarding their suitability for traffic safety applications. All concepts rely on resistive heating of a carbon fibre reinforcement upon application of electric current through the fibres. The stiffness reduction is achieved by a phase transformation due to heating of the material. The phase transformation takes place either in a thermoplastic interphase, in a thermoplastic matrix or in a thermoset matrix, depending on the concept. The different concepts were studied regarding their thermomechanical and processing properties and their ability to reduce their stiffness upon application of an electric current was tested. Moreover, the materials were evaluated regarding their potential for fast activation, which is crucial for applications in traffic safety. Stiffness-reduction was achieved upon application of an electric current, where the activation temperature was between 60 and 120°C and the extent of stiffness-reduction varied between 50 and 90%, depending on the material. The response time was found to depend to a large extent on the amount of material, which leads to the conclusion that smart design solutions are required for larger parts. It is concluded that the concepts vary in their thermal, mechanical and processing properties as well as in their extent of stiffness-reduction upon activation. The results presented in this work prove the feasibility of the studied materials for traffic safety applications and the concepts allow further optimization of the materials for specific applications
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| 4. |
- Baranto, Adad, 1966, et al.
(author)
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Acute chest pain in a top soccer player due to thoracic disc herniation
- 2009
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In: Spine (Phila Pa 1976). - 1528-1159. ; 34:10
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Journal article (peer-reviewed)abstract
- STUDY DESIGN: Case report. OBJECTIVE: An unusual and previously not reported case of upper thoracic disc herniation combined with acute chest pain, is presented. SUMMARY OF BACKGROUND DATA: Disc herniation in the thoracic spine is rare. There are only a few cases of thoracic disc herniation in top athletes presented in the literature. The clinical presentation of a thoracic disc herniation can vary widely depending on its location and morphologic characteristics. Clinically, the acute symptoms may be severe. METHODS: A 24-year-old soccer player with acute left-sided chest pain that started in the middle of a soccer game has been followed clinically and with MRI examinations for 3 years. RESULTS: MRI of the thoracic spine showed a left-sided paramedial disc herniation at T2-T3 level and the right-sided paramedial disc herniation at T3-T4 level. The player was prescribed initial rest and subsequent physical rehabilitation. He had no further symptoms during rehabilitation to full training, and could resume play and remained symptom free for the rest of the season.The following season, the player experienced a similar sudden thoracic pain episode during training. This time the chest pain was right-sided. A new MRI of the thoracic spine showed unchanged findings. The initial rehabilitation was similar to the one used in the first episode. After 15 months with no symptoms during normal life the player was allowed to increase the intensity of training gradually and after 2 years the patient played soccer at elite level again. However, 3 years later the symptoms relapsed and the player ended his career after another rehabilitation period. CONCLUSION: In conclusion, it is important to consider thoracic disc herniation as acute chest pain in athletes and that the long-term prognosis of this entity is not always good.
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| 5. |
- Baranto, Adad, 1966, et al.
(author)
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Acute injury of an intervertebral disc in an elite tennis player: a case report.
- 2010
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In: Spine. - 1528-1159 .- 0362-2436. ; 35:6
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Journal article (peer-reviewed)abstract
- A case report.To present a previously not described rare case of intradiscal hematoma due to acute trauma in an elite tennis player.Several studies have demonstrated a high frequency of radiological changes in the spine of athletes, especially in sports with high loads on the back. Signs of disc degeneration without disc herniation have frequently been found in magnetic resonance imaging (MRI) studies of the spine of athletes. It has also been shown that radiological abnormalities of the spine in young athletes are correlated to back pain.An elite male tennis player experienced pain in the right buttock after a backhand stroke. He was successfully treated for hip problems and started to play competitive tennis, 2 weeks later. After few games, a backhand stroke again resulted in intense pain projected in the os coccyx region. At examination, there were no neurologic disturbances. At palpation over the spinal processes (Springing test) of L1-L2, the patient experienced intense pain projected to the os coccyx region.MRI examination showed an injured L1-L2 disc with fluid inside the disc with a signal similar to blood. Four additional MRI examinations were performed 2 weeks and 2 years after the injury until disc degeneration is formed. Radiograph examination before and 2 years after the injury is available.In conclusion, trauma in athletes can cause intradiscal hematoma, which probably is a new etiology for disc degeneration. Also that sudden onset of pain in the hip or the gluteal region may be caused by referred pain due to a disc lesion. Intradiscal hematoma can be visualized using MRI.
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| 6. |
- Baranto, Adad, 1966, et al.
(author)
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Back pain and degenerative abnormalities in the spine of young elite divers: a 5-year follow-up magnetic resonance imaging study
- 2006
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In: Knee Surg Sports Traumatol Arthrosc. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 14:9, s. 907-14
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Journal article (peer-reviewed)abstract
- Several studies have been published on disc degeneration among young athletes in sports with great demands on the back, but few on competitive divers; however, there are no long-term follow-up studies. Twenty elite divers between 10 and 21 years of age, with the highest possible national ranking, were selected at random without knowledge of previous or present back injuries or symptoms for an MRI study of the thoraco-lumbar spine in a 5-year longitudinal study. The occurrence of MRI abnormalities and their correlation with back pain were evaluated. Eighty-nine percent of the divers had a history of back pain and the median age at the first episode of back pain was 15 years. Sixty-five percent of the divers had MRI abnormalities in the thoraco-lumbar spine already at baseline. Only one diver without abnormalities at baseline had developed abnormalities at follow-up. Deterioration of any type of abnormality was found in 9 of 17 (53%) divers. Including all disc levels in all divers, the total number of abnormalities increased by 29% at follow-up, as compared to baseline. The most common abnormalities were reduced disc signal, Schmorl's nodes, and disc height reduction. Since almost all divers had previous or present back pain, a differentiated analysis of the relationship between pain and MRI findings was not possible. However, the high frequency of both back pain and MRI changes suggests a causal relationship. In conclusion, elite divers had high frequency of back pain at young ages and they run a high risk of developing degenerative abnormalities of the thoraco-lumbar spine, probably due to injuries to the spine during the growth spurt.
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| 7. |
- Baranto, Adad, 1966, et al.
(author)
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Back pain and MRI changes in the thoraco-lumbar spine of top athletes in four different sports: a 15-year follow-up study
- 2009
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In: Knee surgery, Sports traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 17:9, s. 1125-1134
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Journal article (peer-reviewed)abstract
- A total 71 male athletes (weight lifters, wrestlers, orienteers, and ice-hockey players) and 21 non-athletes were randomly selected, for a baseline MRI study. After 15 years all the participants at baseline were invited to take part in a follow-up examination, including a questionnaire on back pain and a follow-up MRI examination. Thirty-two athletes and all non-athletes had disc height reduction at one or several disc levels. Disc degeneration was found in more than 90% of the athletes and deterioration had occurred in 88% of the athletes, with the highest frequency in weight lifters and ice-hockey players. 78% of the athletes and 38% of the non-athletes reported previous or present history of back pain at baseline and 71 and 75%, respectively at follow-up. There was no statistically significant correlation between back pain and MRI changes. In conclusion, athletes in sports with severe or moderate demands on the back run a high risk of developing disc degeneration and other abnormalities of the spine on MRI and they report high frequency of back pain. The study confirmed our hypothesis, i.e. that most of the spinal abnormalities in athletes seem to occur during the growth spurt, since the majority of the abnormalities demonstrated at follow-up MRI after the sports career were present already at baseline. The abnormalities found at young age deteriorated to a varying degree during the 15-year follow-up, probably due to a combination of continued high load sporting activities and normal ageing. Preventive measures should be considered to avoid the development of these injuries in young athletes.
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| 8. |
- Baranto, Adad, 1966, et al.
(author)
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Fracture patterns of the adolescent porcine spine: an experimental loading study in bending-compression
- 2005
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In: Spine. - 1528-1159. ; 30:1, s. 75-82
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Journal article (peer-reviewed)abstract
- STUDY DESIGN: To expose functional spinal units from adolescent porcine to mechanical flexion-compression and extension-compression to failure. The biomechanical, radiologic, magnetic resonance imaging, and histologic characteristics are described. OBJECTIVES: The aim of the present study was to investigate the fracture pattern of functional spinal units from adolescent porcine lumbar spines in in vitro compression loading and bending. SUMMARY OF BACKGROUND DATA: In several studies, it has been shown that the adolescent spine, especially the vertebral growth zones, is vulnerable to trauma. A high frequency of abnormalities affecting the spine has been found among athletes participating in sports with high demands on the back. The etiology of these abnormalities is still a controversial issue. METHODS: Sixteen functional spinal units obtained from eight adolescent male pigs were used. Eight functional spinal units were exposed to flexion-compression and eight functional spinal units to extension-compression loading to failure. They were examined with plain radiography and magnetic resonance imaging before and after the loading. The functional spinal units were finally examined macroscopically and histologically. RESULTS: Fractures/separations were seen in the growth zone anteriorly and more frequently, posteriorly in functional spinal units exposed to flexion-compression. In the extension-compression group, such injuries occurred only anteriorly. Only large fractures could be seen on plain radiographs and on magnetic resonance imaging. Macroscopically, a fracture/separation could be seen in 15 cases and histologically in all 16 cases. The median angle at failure for the flexion group was 17 degrees (range, 12-19) and for the extension group 17 degrees (range, 13-19 degrees). The median ultimate compression load in the flexion-compression group was 1894 N (range, 1607-3138 N) and in the extension-compression group 1801 N (range, 1158-2368 N). CONCLUSIONS: The weakest part of the growing porcine lumbar spine, when compressed into flexion- or extension-compression, was the growth zone. The injury was more extensive in extension loading than during flexion loading. Growth zone injuries of the adolescent spine may go undetected on plain radiographs and magnetic resonance imaging.
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| 9. |
- Baranto, Adad, 1966, et al.
(author)
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Vertebral fractures and separations of endplates after traumatic loading of adolescent porcine spines with experimentally-induced disc degeneration
- 2005
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In: Clin Biomech (Bristol, Avon). - : Elsevier BV. - 0268-0033. ; 20:10, s. 1046-54
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Journal article (peer-reviewed)abstract
- BACKGROUND: Abnormalities of the intervertebral discs have been found in a high frequency among young elite athletes. Several studies have also reported that the adolescent spine, especially the vertebral growth zones, is vulnerable to trauma. However, there is incomplete knowledge regarding the injury mechanism of the growing spine. In this study, the injury patterns of the adolescent porcine spine with disc degeneration were examined. METHODS: Twenty-four male pigs were used. A degenerative disc was created by drilling a hole through the cranial endplate of a lumbar vertebra into the disc. Two months later the animals were sacrificed and the degenerative functional spinal units (segments) were harvested. The segments were divided into three groups and exposed to axial compression, flexion compression or extension compression to failure. The load and angle at failure were measured for each group. The segments were examined with magnetic resonance imaging and plain radiography before and after the loading and finally examined macroscopically and histologically. FINDINGS: The degenerated segments required considerably more compressive load to failure than non-degenerated segments. Creating a flexion injury required significantly more load than an extension injury. Fractures and/or separations of the endplates from the vertebral bodies were seen at the margins of the endplates and in the growth zone. Only severe separations and fractures could be seen on plain radiography and magnetic resonance imaging. INTERPRETATION: The weakest part of the adolescent porcine lumbar spine with experimentally-induced degeneration, when loaded in axial compression, flexion compression or extension compression, was the growth zone, and, to a lesser extent, the endplate. Degenerated discs seem to withstand higher mechanical loads than non-degenerated discs, probably due to altered stress distribution.
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| 10. |
- Bi, Huijuan, et al.
(author)
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A frame-shift mutation in COMTD1 is associated with impaired pheomelanin pigmentation in chicken
- 2023
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In: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 19:4
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Journal article (peer-reviewed)abstract
- The biochemical pathway regulating the synthesis of yellow/red pheomelanin is less well characterized than the synthesis of black/brown eumelanin. Inhibitor of gold (IG phenotype) is a plumage colour variant in chicken that provides an opportunity to further explore this pathway since the recessive allele (IG) at this locus is associated with a defect in the production of pheomelanin. IG/IG homozygotes display a marked dilution of red pheomelanin pigmentation, whilst black pigmentation (eumelanin) is only slightly affected. Here we show that a 2-base pair insertion (frame-shift mutation) in the 5th exon of the Catechol-O-methyltransferase containing domain 1 gene (COMTD1), expected to cause a complete or partial loss-of-function of the COMTD1 enzyme, shows complete concordance with the IG phenotype within and across breeds. We show that the COMTD1 protein is localized to mitochondria in pigment cells. Knockout of Comtd1 in a mouse melanocytic cell line results in a reduction in pheomelanin metabolites and significant alterations in metabolites of glutamate/glutathione, riboflavin, and the tricarboxylic acid cycle. Furthermore, COMTD1 overexpression enhanced cellular proliferation following chemical-induced transfection, a potential inducer of oxidative stress. These observations suggest that COMTD1 plays a protective role for melanocytes against oxidative stress and that this supports their ability to produce pheomelanin.
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