| 1. |
- Bombarda, F., et al.
(författare)
-
Runaway electron beam control
- 2019
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
-
- 2018
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
-
Forskningsöversikt (refereegranskat)
|
|
| 3. |
-
- 2018
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:9
-
Tidskriftsartikel (refereegranskat)
|
|
| 4. |
- Meyer, H., et al.
(författare)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Tidskriftsartikel (refereegranskat)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
|
|
| 5. |
- Meyer, H., et al.
(författare)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Tidskriftsartikel (refereegranskat)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
|
|
| 6. |
|
|
| 7. |
- Meyer, H.F., et al.
(författare)
-
Overview of physics studies on ASDEX Upgrade
- 2019
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
-
Forskningsöversikt (refereegranskat)abstract
- The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heating power, flexible heating mix and comprehensive diagnostic set allows studies ranging from mimicking the scrape-off-layer and divertor conditions of ITER and DEMO at high density to fully non-inductive operation (q 95 = 5.5, ) at low density. Higher installed electron cyclotron resonance heating power 6 MW, new diagnostics and improved analysis techniques have further enhanced the capabilities of AUG. Stable high-density H-modes with MW m-1 with fully detached strike-points have been demonstrated. The ballooning instability close to the separatrix has been identified as a potential cause leading to the H-mode density limit and is also found to play an important role for the access to small edge-localized modes (ELMs). Density limit disruptions have been successfully avoided using a path-oriented approach to disruption handling and progress has been made in understanding the dissipation and avoidance of runaway electron beams. ELM suppression with resonant magnetic perturbations is now routinely achieved reaching transiently . This gives new insight into the field penetration physics, in particular with respect to plasma flows. Modelling agrees well with plasma response measurements and a helically localised ballooning structure observed prior to the ELM is evidence for the changed edge stability due to the magnetic perturbations. The impact of 3D perturbations on heat load patterns and fast-ion losses have been further elaborated. Progress has also been made in understanding the ELM cycle itself. Here, new fast measurements of and E r allow for inter ELM transport analysis confirming that E r is dominated by the diamagnetic term even for fast timescales. New analysis techniques allow detailed comparison of the ELM crash and are in good agreement with nonlinear MHD modelling. The observation of accelerated ions during the ELM crash can be seen as evidence for the reconnection during the ELM. As type-I ELMs (even mitigated) are likely not a viable operational regime in DEMO studies of 'natural' no ELM regimes have been extended. Stable I-modes up to have been characterised using -feedback. Core physics has been advanced by more detailed characterisation of the turbulence with new measurements such as the eddy tilt angle - measured for the first time - or the cross-phase angle of and fluctuations. These new data put strong constraints on gyro-kinetic turbulence modelling. In addition, carefully executed studies in different main species (H, D and He) and with different heating mixes highlight the importance of the collisional energy exchange for interpreting energy confinement. A new regime with a hollow profile now gives access to regimes mimicking aspects of burning plasma conditions and lead to nonlinear interactions of energetic particle modes despite the sub-Alfvénic beam energy. This will help to validate the fast-ion codes for predicting ITER and DEMO.
|
|
| 8. |
- Stroth, U., et al.
(författare)
-
Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development
- 2022
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 62:4
-
Tidskriftsartikel (refereegranskat)abstract
- An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L-H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced D α H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts.
|
|
| 9. |
- Ledoux, X, et al.
(författare)
-
Spallation neutron production by 0.8, 1.2, and 1.6 GeV protons on Pb targets
- 1999
-
Ingår i: PHYSICAL REVIEW LETTERS. - : AMERICAN PHYSICAL SOC. - 0031-9007. ; 82:22, s. 4412-4415
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Spallation neutron production in proton induced reactions on Pb targets at 0.8, 1.2, and 1.6 GeV has been measured at the SATURNE accelerator. Double-differential cross sections were obtained over a broad angular range from which averaged neutron multipli
|
|
| 10. |
- Borne, F, et al.
(författare)
-
Spallation neutron spectra measurements .1. Time-of-flight technique
- 1997
-
Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT. - : ELSEVIER SCIENCE BV. - 0168-9002. ; 385:2, s. 339-344
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present an experimental method based on a time-of-flight technique between the tagged incident particles and a thick liquid NE213 scintillator to measure neutron energy spectra from 3 to 400 MeV at the Saturne synchrotron of Saclay. Efficiency measurem
|
|
| 11. |
- Martinez, E, et al.
(författare)
-
Spallation neutron spectra measurements .2. Proton recoil spectrometer
- 1997
-
Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT. - : ELSEVIER SCIENCE BV. - 0168-9002. ; 385:2, s. 345-353
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present the experimental method conceived to measure high energy neutrons in the range (200 less than or equal to E less than or equal to 1600 MeV). The neutrons produce recoil protons in a liquid hydrogen converter. Momentum evaluation and identificat
|
|
| 12. |
- Dommersnes, Paul Gunnar, 1971, et al.
(författare)
-
Marangoni transport in lipid nanotubes
- 2005
-
Ingår i: Europhysics Letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 70:2, s. 271-277
-
Tidskriftsartikel (refereegranskat)abstract
- We give a simple picture of transient and stationary transport in lipid nanotubes connecting two vesicles, when a difference of membrane tension is imposed at time t = 0, either by pressing one vesicle with a micro-fiber, or by adding a surplus of membrane lipid. The net result is a transport of membrane from the tense towards the floppy vesicle. In the early stage, the tube remains cylindrical, and the gradient of surface tension gives rise to two opposite flows of the internal liquid: a Marangoni flow towards the direction of high tension, and a Poiseuille flow (induced by Laplace pressures) in the opposite direction. At longer time, the tube reaches a stationary state, where curvature and Laplace pressure are balanced. Marangoni flows dominate for giant vesicles, where Laplace pressure is negligible.
|
|
| 13. |
- Bellani, Giacomo, et al.
(författare)
-
Epidemiology, Patterns of Care, and Mortality for Patients With Acute Respiratory Distress Syndrome in Intensive Care Units in 50 Countries
- 2016
-
Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 315:8, s. 788-800
-
Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Limited information exists about the epidemiology, recognition, management, and outcomes of patients with the acute respiratory distress syndrome (ARDS). OBJECTIVES To evaluate intensive care unit (ICU) incidence and outcome of ARDS and to assess clinician recognition, ventilation management, and use of adjuncts-for example prone positioning-in routine clinical practice for patients fulfilling the ARDS Berlin Definition. DESIGN, SETTING, AND PARTICIPANTS The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents. EXPOSURES Acute respiratory distress syndrome. MAIN OUTCOMES AND MEASURES The primary outcome was ICU incidence of ARDS. Secondary outcomes included assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS. RESULTS Of 29 144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0%(95% CI, 28.2%-31.9%); of moderate ARDS, 46.6%(95% CI, 44.5%-48.6%); and of severe ARDS, 23.4%(95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4%(95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5%(95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1%(95% CI, 38.2-42.1), whereas 82.6%(95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3%(95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9%(95% CI, 31.4%-38.5%) for those with mild, 40.3%(95% CI, 37.4%-43.3%) for those with moderate, and 46.1%(95% CI, 41.9%-50.4%) for those with severe ARDS. CONCLUSIONS AND RELEVANCE Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS.
|
|
| 14. |
- Bellani, Giacomo, et al.
(författare)
-
Noninvasive Ventilation of Patients with Acute Respiratory Distress Syndrome. Insights from the LUNG SAFE Study.
- 2017
-
Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X .- 1535-4970. ; 195:1, s. 67-77
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale: Noninvasive ventilation (NIV) is increasingly used in patients with acute respiratory distress syndrome (ARDS). The evidence supporting NIV use in patients with ARDS remains relatively sparse.Objectives: To determine whether, during NIV, the categorization of ARDS severity based on the PaO2/FiO2 Berlin criteria is useful.Methods: The LUNG SAFE (Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure) study described the management of patients with ARDS. This substudy examines the current practice of NIV use in ARDS, the utility of the PaO2/FiO2 ratio in classifying patients receiving NIV, and the impact of NIV on outcome.Measurements and Main Results: Of 2,813 patients with ARDS, 436 (15.5%) were managed with NIV on Days 1 and 2 following fulfillment of diagnostic criteria. Classification of ARDS severity based on PaO2/FiO2 ratio was associated with an increase in intensity of ventilatory support, NIV failure, and intensive care unit (ICU) mortality. NIV failure occurred in 22.2% of mild, 42.3% of moderate, and 47.1% of patients with severe ARDS. Hospital mortality in patients with NIV success and failure was 16.1% and 45.4%, respectively. NIV use was independently associated with increased ICU (hazard ratio, 1.446 [95% confidence interval, 1.159–1.805]), but not hospital, mortality. In a propensity matched analysis, ICU mortality was higher in NIV than invasively ventilated patients with a PaO2/FiO2 lower than 150 mm Hg.Conclusions: NIV was used in 15% of patients with ARDS, irrespective of severity category. NIV seems to be associated with higher ICU mortality in patients with a PaO2/FiO2 lower than 150 mm Hg.
|
|
| 15. |
- Brochard, Laurent, et al.
(författare)
-
Clinical review: Respiratory monitoring in the ICU - a consensus of 16.
- 2012
-
Ingår i: Critical care (London, England). - : Springer Science and Business Media LLC. - 1466-609X .- 1364-8535. ; 16:2
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Monitoring plays an important role in the current management of patients with acute respiratory failure but sometimes lacks definition regarding which 'signals' and 'derived variables' should be prioritized as well as specifics related to timing (continuous versus intermittent) and modality (static versus dynamic). Many new techniques of respiratory monitoring have been made available for clinical use recently, but their place is not always well defined. Appropriate use of available monitoring techniques and correct interpretation of the data provided can help improve our understanding of the disease processes involved and the effects of clinical interventions. In this consensus paper, we provide an overview of the important parameters that can and should be monitored in the critically ill patient with respiratory failure and discuss how the data provided can impact on clinical management.
|
|
| 16. |
- Charles-Orszag, A, et al.
(författare)
-
Adhesion to nanofibers drives cell membrane remodeling through one-dimensional wetting
- 2018
-
Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 4450-
-
Tidskriftsartikel (refereegranskat)abstract
- The shape of cellular membranes is highly regulated by a set of conserved mechanisms that can be manipulated by bacterial pathogens to infect cells. Remodeling of the plasma membrane of endothelial cells by the bacterium Neisseria meningitidis is thought to be essential during the blood phase of meningococcal infection, but the underlying mechanisms are unclear. Here we show that plasma membrane remodeling occurs independently of F-actin, along meningococcal type IV pili fibers, by a physical mechanism that we term ‘one-dimensional’ membrane wetting. We provide a theoretical model that describes the physical basis of one-dimensional wetting and show that this mechanism occurs in model membranes interacting with nanofibers, and in human cells interacting with extracellular matrix meshworks. We propose one-dimensional wetting as a new general principle driving the interaction of cells with their environment at the nanoscale that is diverted by meningococci during infection.
|
|
| 17. |
- De Angeli, M., et al.
(författare)
-
Post-mortem and in-situ investigations of magnetic dust in ASDEX Upgrade
- 2023
-
Ingår i: Nuclear Materials and Energy. - : Elsevier BV. - 2352-1791. ; 36
-
Tidskriftsartikel (refereegranskat)abstract
- Pre-plasma mobilization of magnetic dust can be an important issue for future fusion reactors where plasma breakdown is critical. A combined on-line and off-line study of magnetic dust in ASDEX Upgrade is reported. Post-mortem collection revealed similar composition and morphology compared to other tokamaks, but the overall amount was much smaller. Optical and IR camera diagnostics excluded dust flybys prior to plasma start-up. The negative detection is discussed in light of the magnetic dust properties, the strength of mobilizing forces and the temporal evolution of the magnetic field.
|
|
| 18. |
- Grasselli, Giacomo, et al.
(författare)
-
ESICM guidelines on acute respiratory distress syndrome : definition, phenotyping and respiratory support strategies
- 2023
-
Ingår i: Intensive Care Medicine. - : Springer Nature. - 0342-4642 .- 1432-1238. ; 49, s. 727-759
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of these guidelines is to update the 2017 clinical practice guideline (CPG) of the European Society of Intensive Care Medicine (ESICM). The scope of this CPG is limited to adult patients and to non-pharmacological respiratory support strategies across different aspects of acute respiratory distress syndrome (ARDS), including ARDS due to coronavirus disease 2019 (COVID-19). These guidelines were formulated by an international panel of clinical experts, one methodologist and patients' representatives on behalf of the ESICM. The review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence and grade recommendations and the quality of reporting of each study based on the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) network guidelines. The CPG addressed 21 questions and formulates 21 recommendations on the following domains: (1) definition; (2) phenotyping, and respiratory support strategies including (3) high-flow nasal cannula oxygen (HFNO); (4) non-invasive ventilation (NIV); (5) tidal volume setting; (6) positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM); (7) prone positioning; (8) neuromuscular blockade, and (9) extracorporeal life support (ECLS). In addition, the CPG includes expert opinion on clinical practice and identifies the areas of future research.
|
|
| 19. |
- Guérin, C, et al.
(författare)
-
A prospective international observational prevalence study on prone positioning of ARDS patients : the APRONET (ARDS Prone Position Network) study
- 2018
-
Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 44:1, s. 22-37
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: While prone positioning (PP) has been shown to improve patient survival in moderate to severe acute respiratory distress syndrome (ARDS) patients, the rate of application of PP in clinical practice still appears low.AIM: This study aimed to determine the prevalence of use of PP in ARDS patients (primary endpoint), the physiological effects of PP, and the reasons for not using it (secondary endpoints).METHODS: The APRONET study was a prospective international 1-day prevalence study performed four times in April, July, and October 2016 and January 2017. On each study day, investigators in each ICU had to screen every patient. For patients with ARDS, use of PP, gas exchange, ventilator settings and plateau pressure (Pplat) were recorded before and at the end of the PP session. Complications of PP and reasons for not using PP were also documented. Values are presented as median (1st-3rd quartiles).RESULTS: Over the study period, 6723 patients were screened in 141 ICUs from 20 countries (77% of the ICUs were European), of whom 735 had ARDS and were analyzed. Overall 101 ARDS patients had at least one session of PP (13.7%), with no differences among the 4 study days. The rate of PP use was 5.9% (11/187), 10.3% (41/399) and 32.9% (49/149) in mild, moderate and severe ARDS, respectively (P = 0.0001). The duration of the first PP session was 18 (16-23) hours. Measured with the patient in the supine position before and at the end of the first PP session, PaO2/FIO2 increased from 101 (76-136) to 171 (118-220) mmHg (P = 0.0001) driving pressure decreased from 14 [11-17] to 13 [10-16] cmH2O (P = 0.001), and Pplat decreased from 26 [23-29] to 25 [23-28] cmH2O (P = 0.04). The most prevalent reason for not using PP (64.3%) was that hypoxemia was not considered sufficiently severe. Complications were reported in 12 patients (11.9%) in whom PP was used (pressure sores in five, hypoxemia in two, endotracheal tube-related in two ocular in two, and a transient increase in intracranial pressure in one).CONCLUSIONS: In conclusion, this prospective international prevalence study found that PP was used in 32.9% of patients with severe ARDS, and was associated with low complication rates, significant increase in oxygenation and a significant decrease in driving pressure.
|
|
| 20. |
- Laffey, John G, et al.
(författare)
-
Potentially modifiable factors contributing to outcome from acute respiratory distress syndrome : the LUNG SAFE study
- 2016
-
Ingår i: Intensive Care Medicine. - : Springer. - 0342-4642 .- 1432-1238. ; 42:12, s. 1865-1876
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To improve the outcome of the acute respiratory distress syndrome (ARDS), one needs to identify potentially modifiable factors associated with mortality.Methods: The large observational study to understand the global impact of severe acute respiratory failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients with severe respiratory failure, conducted in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across five continents. A pre-specified secondary aim was to examine the factors associated with outcome. Analyses were restricted to patients (93.1 %) fulfilling ARDS criteria on day 1-2 who received invasive mechanical ventilation.Result: 2377 patients were included in the analysis. Potentially modifiable factors associated with increased hospital mortality in multivariable analyses include lower PEEP, higher peak inspiratory, plateau, and driving pressures, and increased respiratory rate. The impact of tidal volume on outcome was unclear. Having fewer ICU beds was also associated with higher hospital mortality. Non-modifiable factors associated with worsened outcome from ARDS included older age, active neoplasm, hematologic neoplasm, and chronic liver failure. Severity of illness indices including lower pH, lower PaO2/FiO2 ratio, and higher non-pulmonary SOFA score were associated with poorer outcome. Of the 578 (24.3 %) patients with a limitation of life-sustaining therapies or measures decision, 498 (86.0 %) died in hospital. Factors associated with increased likelihood of limitation of life-sustaining therapies or measures decision included older age, immunosuppression, neoplasia, lower pH and increased non-pulmonary SOFA scores.Conclusions: Higher PEEP, lower peak, plateau, and driving pressures, and lower respiratory rate are associated with improved survival from ARDS.
|
|
| 21. |
- Pham, Tai, et al.
(författare)
-
Outcome of acute hypoxaemic respiratory failure : insights from the LUNG SAFE Study
- 2021
-
Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 57:6
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Current incidence and outcome of patients with acute hypoxaemic respiratory failure requiring mechanical ventilation in the intensive care unit (ICU) are unknown, especially for patients not meeting criteria for acute respiratory distress syndrome (ARDS). Methods: An international, multicentre, prospective cohort study of patients presenting with hypoxaemia early in the course of mechanical ventilation, conducted during four consecutive weeks in the winter of 2014 in 459 ICUs from 50 countries (LUNG SAFE). Patients were enrolled with arterial oxygen tension/inspiratory oxygen fraction ratio <= 300 mmHg, new pulmonary infiltrates and need for mechanical ventilation with a positive end-expiratory pressure of >= 5 cmH(2)O. ICU prevalence, causes of hypoxaemia, hospital survival and factors associated with hospital mortality were measured. Patients with unilateral versus bilateral opacities were compared. Findings: 12 906 critically ill patients received mechanical ventilation and 34.9% with hypoxaemia and new infiltrates were enrolled, separated into ARDS (69.0%), unilateral infiltrate (22.7%) and congestive heart failure (CHF; 8.2%). The global hospital mortality was 38.6%. CHF patients had a mortality comparable to ARDS (44.1% versus 40.4%). Patients with unilateral-infiltrate had lower unadjusted mortality, but similar adjusted mortality compared to those with ARDS. The number of quadrants on chest imaging was associated with an increased risk of death. There was no difference in mortality comparing patients with unilateral-infiltrate and ARDS with only two quadrants involved. Interpretation: More than one-third of patients receiving mechanical ventilation have hypoxaemia and new infiltrates with a hospital mortality of 38.6%. Survival is dependent on the degree of pulmonary involvement whether or not ARDS criteria are reached.
|
|
| 22. |
- Ratynskaia, Svetlana, et al.
(författare)
-
Elastic-plastic adhesive impacts of tungsten dust with metal surfaces in plasma environments
- 2015
-
Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 463, s. 877-880
-
Tidskriftsartikel (refereegranskat)abstract
- Dust-surface collisions impose size selectivity on the ability of dust grains to migrate in scrape-off layer and divertor plasmas and to adhere to plasma-facing components. Here, we report first experimental evidence of dust impact phenomena in plasma environments concerning low-speed collisions of tungsten dust with tungsten surfaces: re-bouncing, adhesion, sliding and rolling. The results comply with the predictions of the model of elastic-perfectly plastic adhesive spheres employed in the dust dynamics code MIGRAINe for sub- to several meters per second impacts of micrometer-range metal dust.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Shalpegin, A., et al.
(författare)
-
Fast camera observations of injected and intrinsic dust in TEXTOR
- 2015
-
Ingår i: Plasma Physics and Controlled Fusion. - : Institute of Physics (IOP). - 0741-3335 .- 1361-6587. ; 57:12
-
Tidskriftsartikel (refereegranskat)abstract
- Stereoscopic fast camera observations of pre-characterized carbon and tungsten dust injection in TEXTOR are reported, along with the modelling of tungsten particle trajectories with MIGRAINe. Particle tracking analysis of the video data showed significant differences in dust dynamics: while carbon flakes were prone to agglomeration and explosive destruction, spherical tungsten particles followed quasi-inertial trajectories. Although this inertial nature prevented any validation of the force models used in MIGRAINe, comparisons between the experimental and simulated lifetimes provide a direct evidence of dust temperature overestimation in dust dynamics codes. Furthermore, wide-view observations of the TEXTOR interior revealed the main production mechanism of intrinsic carbon dust, as well as the location of probable dust remobilization sites.
|
|
| 27. |
- Shalpegin, A., et al.
(författare)
-
Highly resolved measurements of dust motion in the sheath boundary of magnetized plasmas
- 2015
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 55:11
-
Tidskriftsartikel (refereegranskat)abstract
- Dust trajectories have been recorded with an unprecedented, under fusion-relevant plasma conditions, spatial resolution of 9 mu m/pixel in Pilot-PSI. The optical setup allowed the use of fast cameras as a basic microscope. It is demonstrated that such a resolution is essential for the correct interpretation of experiments on several aspects of dust-surface interactions. Highly resolved tungsten dust dynamics measurements are presented from dedicated experiments on dust collisions with plasma facing components, motion in the vicinity of castellated samples and remobilization from planar samples.
|
|
| 28. |
- Tolias, Panagiotis, et al.
(författare)
-
Dust remobilization in fusion plasmas under steady state conditions
- 2016
-
Ingår i: Plasma Physics and Controlled Fusion. - : Institute of Physics (IOP). - 0741-3335 .- 1361-6587. ; 58:2
-
Tidskriftsartikel (refereegranskat)abstract
- The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization in fusion devices under steady state conditions are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic remobilization conditions-direct lift-up, sliding, rolling-are formulated. A novel experimental technique is proposed, based on controlled adhesion of dust grains on tungsten samples combined with detailed mapping of the dust deposition profile prior and post plasma exposure. Proof-of-principle experiments in the TEXTOR tokamak and the EXTRAP-T2R reversed-field pinch are presented. The versatile environment of the linear device Pilot-PSI allowed for experiments with different magnetic field topologies and varying plasma conditions that were complemented with camera observations.
|
|
| 29. |
- Tolias, Panagiotis, 1984-, et al.
(författare)
-
Experimental validation of the analytical model for tungsten dust - wall mechanical impacts incorporated in the MIGRAINe dust dynamics code
- 2017
-
Ingår i: NUCLEAR MATERIALS AND ENERGY. - : Elsevier BV. - 2352-1791. ; 12, s. 524-529
-
Tidskriftsartikel (refereegranskat)abstract
- Mechanical dust-wall collisions are unavoidable in fusion devices and their accurate modeling is essential for the understanding of dust transport. The MIGRAINe dust dynamics code features analytical models addressing all facets of dust-surface impacts, some aspects of which have not been experimentally validated thus far. Dedicated dust injection experiments have been carried out in Pilot-PSI resulting to the visualization of in-plasma tungsten dust-surface impacts with an unprecedented resolution. They allowed for a calibration of key quantities of the MIGRAINe impact model.
|
|
| 30. |
- Vignitchouk, Ladislas, et al.
(författare)
-
Validating heat balance models for tungsten dust in cold dense plasmas
- 2018
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP PUBLISHING LTD. - 0741-3335 .- 1361-6587. ; 60:11
-
Tidskriftsartikel (refereegranskat)abstract
- The first comparison of dust radius and surface temperature estimates, obtained from spectroscopic measurements of thermal radiation, with simulations of dust heating and vaporization by the MIGRAINe dust dynamics code is reported. The measurements were performed during controlled tungsten dust injection experiments in the cold and dense plasmas of Pilot-PSI, reproducing ITER divertor conditions. The comparison has allowed us to single out the dominating role of the work function contribution to the dust heating budget. However, in the plasmas of interest, dust was found to enter the strong vaporization regime, in which its temperature is practically insensitive to plasma properties and the various uncertainties in modeling. This makes the dust temperature a poor figure of merit for model validation purposes. On the other hand, simple numerical scalings obtained from orbital-motion-limited estimates were found to be remarkably robust and sufficient to understand the main physics at play in such cold and dense plasmas.
|
|
