| 1. |
- Dankiewicz, Josef, et al.
(författare)
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Hypothermia versus Normothermia after Out-of-Hospital Cardiac Arrest
- 2021
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Ingår i: New England Journal of Medicine. - : MASSACHUSETTS MEDICAL SOC. - 0028-4793 .- 1533-4406. ; 384:24, s. 2283-2294
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Tidskriftsartikel (refereegranskat)abstract
- Hypothermia or Normothermia after Cardiac Arrest This trial randomly assigned patients with coma after out-of-hospital cardiac arrest to undergo targeted hypothermia at 33 degrees C or normothermia with treatment of fever. At 6 months, there were no significant between-group differences regarding death or functional outcomes. Background Targeted temperature management is recommended for patients after cardiac arrest, but the supporting evidence is of low certainty. Methods In an open-label trial with blinded assessment of outcomes, we randomly assigned 1900 adults with coma who had had an out-of-hospital cardiac arrest of presumed cardiac or unknown cause to undergo targeted hypothermia at 33 degrees C, followed by controlled rewarming, or targeted normothermia with early treatment of fever (body temperature, >= 37.8 degrees C). The primary outcome was death from any cause at 6 months. Secondary outcomes included functional outcome at 6 months as assessed with the modified Rankin scale. Prespecified subgroups were defined according to sex, age, initial cardiac rhythm, time to return of spontaneous circulation, and presence or absence of shock on admission. Prespecified adverse events were pneumonia, sepsis, bleeding, arrhythmia resulting in hemodynamic compromise, and skin complications related to the temperature management device. Results A total of 1850 patients were evaluated for the primary outcome. At 6 months, 465 of 925 patients (50%) in the hypothermia group had died, as compared with 446 of 925 (48%) in the normothermia group (relative risk with hypothermia, 1.04; 95% confidence interval [CI], 0.94 to 1.14; P=0.37). Of the 1747 patients in whom the functional outcome was assessed, 488 of 881 (55%) in the hypothermia group had moderately severe disability or worse (modified Rankin scale score >= 4), as compared with 479 of 866 (55%) in the normothermia group (relative risk with hypothermia, 1.00; 95% CI, 0.92 to 1.09). Outcomes were consistent in the prespecified subgroups. Arrhythmia resulting in hemodynamic compromise was more common in the hypothermia group than in the normothermia group (24% vs. 17%, P<0.001). The incidence of other adverse events did not differ significantly between the two groups. Conclusions In patients with coma after out-of-hospital cardiac arrest, targeted hypothermia did not lead to a lower incidence of death by 6 months than targeted normothermia. (Funded by the Swedish Research Council and others; TTM2 ClinicalTrials.gov number, .)
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| 2. |
- Hermann, M., et al.
(författare)
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Nearly stress-free substrates for GaN homoepitaxy
- 2006
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 293:2, s. 462-468
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Tidskriftsartikel (refereegranskat)abstract
- High-quality 300 µm thick GaN crack-free layers grown by hydride vapor phase epitaxy (HVPE) on c-plane sapphire without buffer layers and separated from the substrate by laser lift-off were investigated by high resolution X-ray diffraction (XRD), low-temperature photoluminescence and cathodoluminescence. All these characterization techniques confirm the high structural quality of the resulting material. Lateral X-ray mapping of the free-standing bulk-like GaN shows a homogeneous compressive stress of less than 40 MPa and a heterogeneous stress of about 80 MPa. The formation of twin grains (domains) were observed both in the reciprocal space mapping of the (2 0 .5) reflection and in rocking curve measurements. The latter ones revealed an estimated lateral coherence length of about 1.2 µm. The crystallite size along the c-axis is estimated to be larger than 20 µm. An upper limit of the density of dislocations with a component of the Burgers vector along the c-axis (screw and mixed type) of 1.3×107 cm-2 was extracted from the XRD data, while transmission electron microscopy measurements revealed a dislocation density of 1.7×107 cm-2. Thus, these layers are suitable as lattice-parameter and thermal-expansion matched substrates for strain-free homoepitaxy of GaN-based device heterostructures. © 2006 Elsevier B.V. All rights reserved.
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| 3. |
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| 4. |
- Larsson, M, et al.
(författare)
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When Life-Saving Is Life-Threatening
- 2014
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Ingår i: SCIENCE TRANSLATIONAL MEDICINE. - 1946-6234. ; 6:222
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Lopes-Oliveira, V., et al.
(författare)
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Strain and localization effects in InGaAs(N) quantum wells: Tuning the magnetic response
- 2014
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 116:23
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Tidskriftsartikel (refereegranskat)abstract
- We investigated effects of localization and strain on the optical and magneto-optical properties of diluted nitrogen III-V quantum wells theoretically and experimentally. High-resolution x-ray diffraction, photoluminescence (PL), and magneto-PL measurements under high magnetic fields up to 15 T were performed at low temperatures. Bir-Pikus Hamiltonian formalism was used to study the influence of strain, confinement, and localization effects. The circularly polarized magneto-PL was interpreted considering localization aspects in the valence band ground state. An anomalous behavior of the electron-hole pair magnetic shift was observed at low magnetic fields, ascribed to the increase in the exciton reduced mass due to the negative effective mass of the valence band ground state.
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| 6. |
- Gogova, D, et al.
(författare)
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Microscopic lateral overgrowth by physical vapour transport of GaN on self-organized diamond-like carbon masks
- 2009
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Ingår i: CRYSTAL RESEARCH AND TECHNOLOGY. - : Wiley. - 0232-1300 .- 1521-4079. ; 44:10, s. 1078-1082
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Tidskriftsartikel (refereegranskat)abstract
- Techniques to reduce dislocation densities in GaN grown on foreign substrates are an interesting alternative to bulk growth as long as efficient bulk crystals growth techniques are not available, In this paper a new approach for epitaxial lateral overgrowth (ELO) of GaN through an in-situ grown self-organized amorphous (diamond-like) carbon mask is demonstrated. The ELO was done for the first time by physical vapour transport of Ga, using NH3 as a nitrogen source. The overgrowth results in a decrease of the threading dislocation density by at least one order of magnitude compared to that of the MOCVD GaN/sapphire templates.
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| 7. |
- Greite, Robert, et al.
(författare)
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Free heme and hemopexin in acute kidney injury after cardiopulmonary bypass and transient renal ischemia
- 2023
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Ingår i: Clinical and Translational Science. - 1752-8054. ; 16:12, s. 2729-2743
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Tidskriftsartikel (refereegranskat)abstract
- Free heme is released from hemoproteins during hemolysis or ischemia reperfusion injury and can be pro-inflammatory. Most studies on nephrotoxicity of hemolysis-derived proteins focus on free hemoglobin (fHb) with heme as a prosthetic group. Measurement of heme in its free, non-protein bound, form is challenging and not commonly used in clinical routine diagnostics. In contrast to fHb, the role of free heme in acute kidney injury (AKI) after cardiopulmonary bypass (CPB) surgery is unknown. Using an apo-horseradish peroxidase-based assay, we identified free heme during CPB surgery as predictor of AKI in patients undergoing cardiac valve replacement (n = 37). Free heme levels during CPB surgery correlated with depletion of hemopexin (Hx), a heme scavenger-protein. In mice, the impact of high levels of circulating free heme on the development of AKI following transient renal ischemia and the therapeutic potential of Hx were investigated. C57BL/6 mice were subjected to bilateral renal ischemia/reperfusion injury for 15 min which did not cause AKI. However, additional administration of free heme in this model promoted overt AKI with reduced renal function, increased renal inflammation, and reduced renal perfusion on functional magnetic resonance imaging. Hx treatment attenuated AKI. Free heme administration to sham operated control mice did not cause AKI. In conclusion, free heme is a predictor of AKI in CPB surgery patients and promotes AKI in transient renal ischemia. Depletion of Hx in CPB surgery patients and attenuation of AKI by Hx in the in vivo model encourage further research on Hx therapy in patients with increased free heme levels during CPB surgery.
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| 8. |
- Yates, E. J., et al.
(författare)
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Out-of-hospital cardiac arrest termination of resuscitation with ongoing CPR : An observational study
- 2018
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572. ; 130, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Termination of resuscitation guidelines for out-of-hospital cardiac arrest can identify patients in whom continuing resuscitation has little chance of success. This study examined the outcomes of patients transferred to hospital with ongoing CPR. It assessed outcomes for those who would have met the universal prehospital termination of resuscitation criteria (no shocks administered, unwitnessed by emergency medical services, no return of spontaneous circulation). Methods: A retrospective cohort study of consecutive adult patients who were transported to hospital with ongoing CPR was conducted at three hospitals in the West Midlands, UK between September 2016 and November 2017. Patient characteristics, interventions and response to treatment (ROSC, survival to discharge) were identified. Results: 227 (median age 69 years, 67.8% male) patients were identified. 89 (39.2%) met the universal prehospital termination of resuscitation criteria. Seven (3.1%) were identified with a potentially reversible cause of cardiac arrest. After hospital arrival, patients received few specialist interventions that were not available in the prehospital setting. Most (n = 210, 92.5%) died in the emergency department. 17 were admitted (14 to intensive care), of which 3 (1.3%) survived to hospital discharge. There were no survivors (0%) in those who met the criteria for universal prehospital termination of resuscitation. Conclusion: Overall survival amongst patients transported to hospital with ongoing CPR was very poor. Application of the universal prehospital termination of resuscitation rule, in patients without obvious reversible causes of cardiac arrest, would have allowed resuscitation to have been discontinued at the scene for 39.2% of patients who did not survive.
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| 9. |
- Gogova, D., et al.
(författare)
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HVPE GaN substrates : growth and characterization
- 2010
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 7:7-8, s. 1756-1759
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Tidskriftsartikel (refereegranskat)abstract
- GaN substrates with low dislocation densities were prepared by halide vapor-phase epitaxy (HVPE) on c-plane sapphire and by means of a post-growth laser-induced lift-off or natural stress-induced (self-) separation process. The HVPE growth on InGaN/GaN buffer layers and subsequent self-separation method was seen as advantageous, in comparison with the laser-induced lift-off one, in terms of lower cost and better crystalline quality of the GaN material obtained. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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