| 1. |
- Fischer, J., et al.
(författare)
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In children and adolescents with temporomandibular disorder assembled with juvenile idiopathic arthritis-no association were found between pain and TMJ deformities using CBCT
- 2021
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Ingår i: BMC Oral Health. - : BioMed Central. - 1472-6831. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Children and adolescents with juvenile idiopathic arthritis (JIA) may suffer from temporomandibular disorder (TMD). Due to this, imaging diagnosis is crucial in JIA with non-symptomatic TM joint (TMJ) involvement. The aim of the study was to examine the association between clinical TMD signs/symptoms and cone-beam computed tomography (CBCT) findings of TMJ structural deformities in children and adolescents with JIA. Methods This cross-sectional study is part of a longitudinal prospective multi-centre study performed from 2015-2020, including 228 children and adolescents aged 4-16 years diagnosed with JIA, according to the International League of Associations for Rheumatology (ILAR). For this sub-study, we included the Bergen cohort of 72 patients (32 female, median age 13.1 years, median duration of JIA 4.5 years). Clinical TMD signs/symptoms were registered as pain on palpation, pain on jaw movement, and combined pain of those two. The severity of TMJ deformity was classified as sound (no deformity), mild, or moderate/severe according to the radiographic findings of CBCT. Results Of 72 patients, 21 (29.2%) had pain on palpation at and around the lateral pole, while 41 (56.9%) had TMJ pain upon jaw movement and 26 (36.1%) had pain from both. Of 141 TMJs, 18.4% had mild and 14.2% had moderate/severe structural deformities visible on CBCT. CBCT findings were not significantly associated with either the pain on palpation or the pain on jaw movement. A significant difference was found between structural deformities in CBCT and the combined pain outcome (pain at both palpation and movement) for both TMJs for the persistent oligoarticular subtype (p = 0.031). Conclusions There was no association between painful TMD and CBCT imaging features of the TMJ in patients with JIA, but the oligoarticular subtype of JIA, there was a significant difference associated with TMJ pain and structural CBCT deformities.
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| 2. |
- Gatchell, Michael, et al.
(författare)
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Commissioning of the DESIREE storage rings - a new facility for cold ion-ion collisions
- 2014
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Ingår i: XXVIII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2013). - : Institute of Physics (IOP). ; 488:1
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Konferensbidrag (refereegranskat)abstract
- We report on the ongoing commissioning of the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. Beams of atomic carbon anions (C-) and smaller carbon anion molecules (C-2(-), C-3(-), C-4(-) etc.) have been produced in a sputter ion source, accelerated to 10 keV or 20 keV, and stored successfully in the two electrostatic rings. The rings are enclosed in a common vacuum chamber cooled to below 13 Kelvin. The DESIREE facility allows for studies of internally relaxed single isolated atomic, molecular and cluster ions and for collision experiments between cat-and anions down to very low center-of-mass collision energies (meV scale). The total thermal load of the vacuum chamber at this temperature is measured to be 32 W. The decay rates of stored ion beams have two components: a non-exponential component caused by the space charge of the beam itself which dominates at early times and an exponential term from the neutralization of the beam in collisions with residual gas at later times. The residual gas limited storage lifetime of carbon anions in the symmetric ring is over seven minutes while the 1/e lifetime in the asymmetric ring is measured to be about 30 seconds. Although we aim to improve the storage in the second ring, the number of stored ions are now sufficient for many merged beams experiments with positive and negative ions requiring milliseconds to seconds ion storage.
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| 3. |
- Hartman, Henrik, et al.
(författare)
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First storage of ion beams in the Double Electrostatic Ion-Ring Experiment : DESIREE
- 2013
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 84:5
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Tidskriftsartikel (refereegranskat)abstract
- We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (Cn-, n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2- molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s +/- 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10-14 mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.
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| 4. |
- Thomas, Richard D., et al.
(författare)
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DESIREE : Physics with cold stored ion beams
- 2015
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Ingår i: DR2013. - : EDP Sciences. ; 84, s. 01004-01004
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Konferensbidrag (refereegranskat)abstract
- Here we will briefly describe the commissioning of the Double ElectroStatic Ion Ring ExpEriment (DESIREE) facility at Stockholm University, Sweden. This device uses purely electrostatic focussing and deflection elements and allows ion beams of opposite charge to be confined under extreme high vacuum and cryogenic conditions in separate rings and then merged over a common straight section. This apparatus allows for studies of interactions between cations and anions at very low and well-defined centre-of-mass energies (down to a few meV) and at very low internal temperatures (down to a few K).
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