| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Abdalla Elsayed, Maram E.A., et al.
(författare)
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Incidence of Intraocular Lens Exchange after Cataract Surgery
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Intraocular lens (IOL) exchange after cataract surgery is unusual but may be associated with suboptimal visual outcome. The incidence of IOL exchange has not been consistently estimated. Such information is invaluable when counseling patients prior to cataract surgery. We examined the incidence of, and indications and risk factors for, IOL exchange after cataract surgery. We also assessed visual outcome of eyes that had an IOL exchange. A cohort design was used to estimate the incidence of IOL exchange and a case-control design to identify factors associated with it. All phacoemulsification surgeries with IOL (n = 17415 eyes) during 2010-2017 and those that had a subsequent IOL removal or replacement during the same time period were identified (n = 34 eyes). The incidence of IOL exchange was 2 per 1000 surgeries (95% confidence interval [CI] 1 to 3) over 8 years. Eyes that underwent subsequent IOL removal or replacement were compared with eyes that had cataract surgery only (n = 47) across demographic and clinical characteristics. In a binary logistic regression analysis, two factors were significantly associated with IOL exchange/removal: an adverse event during cataract surgery (adjusted odds ratio [aOR] 19.45; 95% CI 4.89-77.30, P < 0.001) and a pre-existing ocular comorbidity (aOR 10.70; 95% CI 1.69-67.63, P = 0.021). The effect of gender was marginally significant (P = 0.077). Eyes that underwent IOL exchange or explantation were nearly two and a half times more likely to have a final best-corrected visual acuity of <20/60 compared to those that had cataract surgery alone (adjusted RR 2.60 95% CI, 1.13-6.02; P = 0.025).
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| 3. |
- Abdalla Elsayed, Maram E.A., et al.
(författare)
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Sickle cell retinopathy. A focused review
- 2019
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Ingår i: Graefe's Archive for Clinical and Experimental Ophthalmology. - : Springer Science and Business Media LLC. - 0721-832X .- 1435-702X. ; 257:7, s. 1353-1364
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Forskningsöversikt (refereegranskat)abstract
- Purpose: To provide a focused review of sickle cell retinopathy in the light of recent advances in the pathogenesis, multimodal retinal imaging, management of the condition, and migration trends, which may lead to increased prevalence of the condition in the Western world. Methods: Non-systematic focused literature review. Results: Sickle retinopathy results from aggregation of abnormal hemoglobin in the red blood cells in the retinal microcirculation, leading to reduced deformability of the red blood cells, stagnant blood flow in the retinal precapillary arterioles, thrombosis, and ischemia. This may be precipitated by hypoxia, acidosis, and hyperosmolarity. Sickle retinopathy may result in sight threatening complications, such as paracentral middle maculopathy or sequelae of proliferative retinopathy, such as vitreous hemorrhage and retinal detachment. New imaging modalities, such as wide-field imaging and optical coherence tomography angiography, have revealed the microstructural features of sickle retinopathy, enabling earlier diagnosis. The vascular growth factor ANGPTL-4 has recently been identified as a potential mediator of progression to proliferative retinopathy and may represent a possible therapeutic target. Laser therapy should be considered for proliferative retinopathy in order to prevent visual loss; however, the evidence is not very strong. With recent development of wide-field imaging, targeted laser to ischemic retina may prove to be beneficial. Exact control of intraoperative intraocular pressure, including valved trocar vitrectomy systems, may improve the outcomes of vitreoretinal surgery for complications, such as vitreous hemorrhage and retinal detachment. Stem cell transplantation and gene therapy are potentially curative treatments, which may prevent retinopathy. Conclusions: There is lack of evidence regarding the optimal management of sickle retinopathy. Further study is needed to determine if recent progress in the understanding of the pathophysiology and diagnosis of sickle retinopathy may translate into improved management and outcome.
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| 4. |
- Albabtain, Budoor, et al.
(författare)
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Comparison of posterior hyaloid assessment using preoperative optical coherence tomography and intraoperative triamcinolone acetonide staining during vitrectomy
- 2021
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Ingår i: Clinical Ophthalmology. - 1177-5467. ; 15, s. 3939-3945
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare the specificity of diagnosing posterior vitreous detachment (PVD) using preoperative optical coherence tomography (OCT) versus intraoperative triamcinolone acetonide (TA) staining in patients undergoing vitrectomy. Patients and Methods: This retrospective cohort study included patients undergoing pars plana vitrectomy for diverse retinal pathologies. Intraoperatively, surgeons evaluated the posterior hyaloid status with TA staining and compared it with preoperative OCT findings. Results: One hundred six patients underwent intraoperative assessments of posterior hyaloid status, with 72% (76/106) of the eyes showing positive staining. Sixty-two patients had also undergone preoperative OCT. Of the patients diagnosed with PVD on preoperative OCT, 50% (15/30) showed positive TA staining intraoperatively. The sensitivity of preoperative OCT assessment was 83.3%, and its specificity was 65.9%. Conclusion: Preoperative OCT imaging is associated with lower sensitivity and specificity for diagnosing PVD when compared to intraoperative TA staining.
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| 5. |
- Badawi, Abdulrahman, et al.
(författare)
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Cone dystrophy associated with autoimmune polyglandular syndrome type 1
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- To report the association of autoimmune polyglandular syndrome type 1 (APS1) with cone dystrophy in a large Saudi family. This is a Retrospective chart review and prospective genetic testing and ophthalmic examination of a large multiplex consanguineous family. Genetic testing was performed on 14 family members, seven of whom had detailed ophthalmic examinations. Medical history, ocular history and evaluation, visual field testing, full-field electroretinogram (ERG), and Whole Exome Sequencing (WES) results were analyzed. Three family members were homozygous for c.205_208dupCAGG;p.(Asp70Alafs*148) in AIRE and homozygous for c.481-1G>A in PDE6C. One additional family member was homozygous for only the AIRE variant and another additional family member was homozygous for only the PDE6C variant. All patients with homozygosity for the PDE6C variant had cone dystrophy, and all patients with homozygosity for the AIRE variant had APS1. In addition, two of the family members who were homozygous for the PDE6C and AIRE variants had reduced rod function on ERG. We report the co-inheritance for APS1 and PDE6C-related cone dystrophy, an unusual example of two seemingly independent recessive conditions coinciding within a family. Dual molecular diagnosis must be taken into account by ophthalmologists facing unusual constellations of findings, especially in consanguineous families.
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| 6. |
- Maffei, Antonio, 1982-, et al.
(författare)
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Dynamic Mixed Reality Assembly Guidance Using Optical Recognition Methods
- 2023
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Ingår i: Applied Sciences. - : MDPI AG. - 2076-3417. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Augmented (AR) and Mixed Reality (MR) technologies are enablers of the Industry 4.0 paradigm and are spreading at high speed in production. Main applications include design, training, and assembly guidance. The latter is a pressing concern, because assembly is the process that accounts for the biggest portion of total cost within production. Teaching and guiding operators to assemble with minimal effort and error rates is pivotal. This work presents the development of a comprehensive MR application for guiding novice operators in following simple assembly instructions. The app follows innovative programming logic and component tracking in a dynamic environment, providing an immersive experience that includes different guidance aids. The application was tested by experienced and novice users, data were drawn from the performed experiments, and a questionnaire was submitted to collect the users' perception. Results indicate that the MR application was easy to follow and even gave confidence to inexperienced subjects. The guidance support was perceived as useful by the users, though at times invasive in the field of view. Further development effort is required to draw from this work a complete and usable architecture for MR application in assembly, but this research forms the basis to achieve better, more consistent instructions for assembly guidance based on component tracking.
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| 7. |
- Nowilaty, Sawsan R., et al.
(författare)
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Incidence and Natural History of Retinochoroidal Neovascularization in Enhanced S-Cone Syndrome
- 2021
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Ingår i: American Journal of Ophthalmology. - : Elsevier BV. - 0002-9394. ; 222, s. 174-184
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We examined the incidence and natural history of macular retinochoroidal neovascularization (RCN) in enhanced S-cone syndrome (ESCS). Design: Retrospective case series. Methods: This single-center study included 14 of 93 patients with ESCS who had signs of active or inactive RCN in ≥1 eye. We conducted multimodal retinal imaging, full-field electroretinography, and molecular genetic analysis of NR2E3 gene. Our main outcome measures included the cumulative incidence of RCN in ESCS, type of RCN, and mode of evolution of RCN. Results: Fourteen (15.1%) of 93 patients with ESCS had RCN in ≥1 eye at 2 to 27 years of age. All 22 RCNs (21 eyes of 14 patients) were macular. Twelve of the RCNs were active with exudates/hemorrhages. Of these, 5 appeared de novo in a subretinal location, with photographic evidence of no pre-existing lesions. The latter were compatible with type 3 neovascularization or retinal angiomatous proliferation and subsequently evolved into unifocal fibrotic nodules. The remaining active lesions all had some degree of pre-existing fibrosis and remained stable. Ten inactive fibrotic nodules, identical to end-stage de novo lesions, were found and were presumed to represent healed RCNs. Conclusions: RCN, a treatable condition, may occur as early as 2 years of age and may be much more common in patients with ESCS than previously estimated. It may be the primary cause of the unifocal submacular fibrosis that is commonly observed in this condition. Additional research is needed to establish the pathogenesis of RCN in patients with ESCS and its optimal management.
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| 8. |
- Schatz, Patrik, et al.
(författare)
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Serous retinal detachment after panretinal photocoagulation for proliferative diabetic retinopathy : A case report
- 2017
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Ingår i: Journal of Medical Case Reports. - : Springer Science and Business Media LLC. - 1752-1947. ; 11:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Proliferative diabetic retinopathy is a major cause of visual impairment in working-age adults worldwide. Panretinal photocoagulation is a cornerstone in its management; however, it may include a range of side effects and complications, one of these being serous retinal detachment. To the best of our knowledge, this is the first report of the use of intravitreal injection of bevacizumab for serous retinal detachment after panretinal photocoagulation. Case presentation: A 24-year-old Saudi man with poorly controlled type 1 diabetes presented with bilateral progressive proliferative retinopathy in spite of several sessions of panretinal photocoagulation. After one additional such session, he developed bilateral serous retinal detachment and vision loss, which was managed with a single bilateral intravitreal bevacizumab injection. The serous retinal detachment subsided with partial recovery of vision. Conclusions: Serous retinal detachment after panretinal photocoagulation for proliferative diabetic retinopathy is a rare complication nowadays. In this case, it seems that excessive photocoagulation exceeded the energy-absorbing capacity of the retinal pigment epithelium, leading to a disruption of the blood-retinal barrier. A single injection of bilateral intravitreal bevacizumab was sufficient to control the serous retinal detachment. This effect may have been due to a reduction of vascular leakage resulting from the mechanism of action of this drug. No complications were noted from the injection. Caution should be exerted when attempting bilateral panretinal photocoagulation.
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| 9. |
- Semidey, Valmore, et al.
(författare)
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Surgical management of hemorrhagic retinal detachment secondary to peripheral exudative hemorrhagic chorioretinopathy
- 2021
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Ingår i: Middle East African Journal of Ophthalmology. - 0974-9233. ; 28:1, s. 57-59
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the study is to report a case of peripheral exudative hemorrhagic chorioretinopathy (PEHCR), managed surgically with favorable visual outcome. A 66-year-old female presented with painless visual loss due to dense vitreous and subretinal hemorrhage extending from the far periphery to the macula. Pars plana vitrectomy (PPV) with subretinal tissue plasminogen activator (TPA) injection was performed resulting in good anatomical and visual outcome. PEHCR can present with severe visual loss. Surgical management with PPV and subretinal TPA injection might result in favorable anatomical and visual outcome.
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| 10. |
- Tinetti, G., et al.
(författare)
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A chemical survey of exoplanets with ARIEL
- 2018
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Ingår i: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 46:1, s. 135-209
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Tidskriftsartikel (refereegranskat)abstract
- Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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