| 1. |
- Anghel, Clara, et al.
(författare)
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Gas-tight oxides – Reality or just a Hope
- 2006
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 522-523, s. 93-101
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Tidskriftsartikel (refereegranskat)abstract
- A better understanding of the transport properties of gases in oxides is certainly very important in many applications. In the case of metals, a general protection measure against corrosion implies formation of a dense metal oxide scale. The scale should act as a barrier against gas transport and consequently it needs to be gas-tight. This is often assumed but rarely, if ever, confirmed. Hence there is a need for characterization of micro- and/or meso- pores formed especially during the early oxidation stage of metallic materials. This paper presents a novel and relatively straightforward method for characterization of gas release from an oxide previously equilibrated in a controlled atmosphere. The geometry of the sample is approximated to be a plate. The plate can be self-supporting or constitute a scale on a substrate. A mathematical model for calculation of diffusivity and gas content is given for this geometry. A desorption experiment, involving a mass spectrometer placed in ultra high vacuum, can be used to determine diffusivity and amount of gas released with aid of the mathematical model. The method is validated in measurements of diffusivity and solubility of He in quartz and applied in characterization of two Zr-oxides and one Fe oxide. From the outgassed amounts of water and nitrogen the H2O/N-2 molar ratio can be used to estimate an effective pore size in oxides.
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| 2. |
- Gilje, Patrik, et al.
(författare)
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The association between plasma miR-122-5p release pattern at admission and all-cause mortality or shock after out-of-hospital cardiac arrest
- 2019
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Ingår i: Biomarkers. - 1354-750X. ; 24:1, s. 29-35
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Tidskriftsartikel (refereegranskat)abstract
- Background: Data suggests that the plasma levels of the liver-specific miR-122-5p might both be a marker of cardiogenic shock and a prognostic marker of out-of-hospital cardiac arrest (OHCA). Our aim was to characterize plasma miR-122-5p at admission after OHCA and to assess the association between miR-122-5p and relevant clinical factors such all-cause mortality and shock at admission after OHCA. Methods: In the pilot trial, 10 survivors after OHCA were compared to 10 age- and sex-matched controls. In the main trial, 167 unconscious survivors of OHCA from the Targeted Temperature Management (TTM) trial were included. Results: In the pilot trial, plasma miR-122-5p at admission after OHCA was 400-fold elevated compared to controls. In the main trial, plasma miR-122-5p at admission was independently associated with lactate and bystander cardiopulmonary resuscitation. miR-122-5p at admission was not associated with shock at admission (p = 0.14) or all-cause mortality (p = 0.35). Target temperature (33 °C vs 36 °C) was not associated with miR-122-5p levels at any time point. Conclusions: After OHCA, miR-122-5p demonstrated a marked acute increase in plasma and was independently associated with lactate and bystander resuscitation. However, miR-122-5p at admission was not associated with all-cause mortality or shock at admission.
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| 3. |
- Grand, Johannes, et al.
(författare)
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Cardiac output during targeted temperature management and renal function after out-of-hospital cardiac arrest
- 2019
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Ingår i: Journal of Critical Care. - : Elsevier BV. - 0883-9441. ; 54, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: After resuscitation from out-of-hospital cardiac arrest (OHCA), renal injury and hemodynamic instability are common. We aimed to assess the association between low cardiac output during targeted temperature management (TTM) and acute kidney injury (AKI) after OHCA. Materials and methods: Single-center substudy of 171 patients included in the prospective, randomized TTM-trial. Hemodynamic evaluation was performed with serial measurements by pulmonary artery catheter. AKI was the primary endpoint and was defined according to the KDIGO-criteria. Results: Of 152 patients with available hemodynamic data, 49 (32%) had AKI and 21 (14%) had AKI with need for renal replacement therapy (RRT) in the first three days. During targeted temperature management, patients with AKI had higher heart rate (11 beats/min, pgroup < 0.0001), higher mean arterial pressure (MAP) (4 mmHg, pgroup = 0.001) and higher lactate (1 mmol/L, pgroup < 0.0001) compared to patients without AKI. However, there was no difference in cardiac index (pgroup = 0.25). In a multivariate logistic regression model, adjusting for potential confounders, MAP (p = .03), heart rate (p = .01) and lactate (p = .006), but not cardiac output, were independently associated with AKI. Conclusions: Blood pressure, heart rate and lactate, but not cardiac output, during 24 h of TTM were associated with AKI in comatose OHCA-patients.
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| 4. |
- Lilja, Gisela, et al.
(författare)
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Cognitive Function in Survivors of Out-of-Hospital Cardiac Arrest After Target Temperature Management at 33ºC Versus 36ºC.
- 2015
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Ingår i: Circulation. - 1524-4539. ; 131:15, s. 77-1340
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Tidskriftsartikel (refereegranskat)abstract
- -Target temperature management is recommended as a neuro-protective strategy after out-of-hospital cardiac arrest. Potential effects of different target temperatures on cognitive impairment commonly described in survivors are not sufficiently investigated. The primary aim of this study was to evaluate whether a target temperature of 33ºC compared to 36ºC was favourable for cognitive function, and secondary to describe cognitive impairment in cardiac arrest survivors in general.
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| 5. |
- Lilja, Gisela, et al.
(författare)
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Cognitive Function in Survivors of Out-of-Hospital Cardiac Arrest After Target Temperature Management at 33 degrees C Versus 36 degrees C
- 2015
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Ingår i: Circulation. - 0009-7322. ; 131:15, s. 1340-1349
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Tidskriftsartikel (refereegranskat)abstract
- -Target temperature management is recommended as a neuro-protective strategy after out-of-hospital cardiac arrest. Potential effects of different target temperatures on cognitive impairment commonly described in survivors are not sufficiently investigated. The primary aim of this study was to evaluate whether a target temperature of 33ºC compared to 36ºC was favourable for cognitive function, and secondary to describe cognitive impairment in cardiac arrest survivors in general.
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| 6. |
- Moore, R. G., et al.
(författare)
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Manifestations of broken symmetry : The surface phases of Ca2-xSrxRuO4
- 2008
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 100:6, s. 066102-
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Tidskriftsartikel (refereegranskat)abstract
- The surface structural phases of Ca2-xSrxRuO4 are investigated using quantitative low energy electron diffraction. The broken symmetry at the surface enhances the structural instability against the RuO6 rotational distortion while diminishing the instability against the RuO6 tilt distortion occurring within the bulk crystal. As a result, suppressed structural and electronic surface phase transition temperatures are observed, including the appearance of an inherent Mott metal-to-insulator transition for x=0.1 and possible modifications of the surface quantum critical point near x(c)similar to 0.5.
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| 7. |
- Nascimento, V. B., et al.
(författare)
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Procedure for LEED I-V structural analysis of metal oxide surfaces : Ca1.5Sr0.5RuO4(001)
- 2007
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 75:3, s. 035408-
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Tidskriftsartikel (refereegranskat)abstract
- Transition metal oxides (TMOs) are famous for the intimate coupling between the lattice, electrons, and spin, creating exotic functionality. Creating a surface, breaking the symmetry, should result in lattice distortions that due to the close coupling could create different "surface phases." Historically it has been very difficult to use low energy electron diffraction I-V to quantitatively determine the surface structure of TMOs. A signature of this problem is the large values commonly reported in the literature of the Pendry reliability factor (R-P), which is used to quantify the agreement between experimental data and calculated diffraction. In this paper we describe a consistent procedure for determining the phase shifts using an optimized muffin-tin potential approach combined with an energy-dependent real and imaginary inner potential. This procedure is used to determine the surface structure of the layered TMO Ca1.5Sr0.5RuO4. An acceptable Pendry reliability factor is achieved (R-P=0.28).
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| 8. |
- Nascimento, V. B., et al.
(författare)
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Surface-Stabilized Nonferromagnetic Ordering of a Layered Ferromagnetic Manganite
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:22, s. 227201-
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Tidskriftsartikel (refereegranskat)abstract
- An outstanding question regarding the probing or possible device applications of correlated electronic materials (CEMs) with layered structure is the extent to which their bulk and surface properties differ or not. The broken translational symmetry at the surface can lead to distinct functionality due to the charge, lattice, orbital, and spin coupling. Here we report on the case of bilayered manganites with hole doping levels corresponding to bulk ferromagnetic order. We find that, although the hole doping level is measured to be the same as in the bulk, the surface layer is not ferromagnetic. Further, our low-energy electron diffraction and x-ray measurements show that there is a c-axis collapse in the outermost layer. Bulk theoretical calculations reveal that, even at fixed doping level, the relaxation of the Jahn-Teller distortion at the surface is consistent with the stabilization of an A-type antiferromagnetic state.
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| 9. |
- Nielsen, Niklas, et al.
(författare)
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Target temperature management after out-of-hospital cardiac arrest-a randomized, parallel-group, assessor-blinded clinical trial-rationale and design
- 2012
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Ingår i: American Heart Journal. - : Elsevier. - 0002-8703 .- 1097-6744. ; 163:4, s. 541-548
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Tidskriftsartikel (refereegranskat)abstract
- Background Experimental animal studies and previous randomized trials suggest an improvement in mortality and neurologic function with induced hypothermia after cardiac arrest. International guidelines advocate the use of a target temperature management of 32 degrees C to 34 degrees C for 12 to 24 hours after resuscitation from out-of-hospital cardiac arrest. A systematic review indicates that the evidence for recommending this intervention is inconclusive, and the GRADE level of evidence is low. Previous trials were small, with high risk of bias, evaluated select populations, and did not treat hyperthermia in the control groups. The optimal target temperature management strategy is not known. less thanbrgreater than less thanbrgreater thanMethods The TTM trial is an investigator-initiated, international, randomized, parallel-group, and assessor-blinded clinical trial designed to enroll at least 850 adult, unconscious patients resuscitated after out-of-hospital cardiac arrest of a presumed cardiac cause. The patients will be randomized to a target temperature management of either 33 degrees C or 36 degrees C after return of spontaneous circulation. In both groups, the intervention will last 36 hours. The primary outcome is all-cause mortality at maximal follow-up. The main secondary outcomes are the composite outcome of all-cause mortality and poor neurologic function (cerebral performance categories 3 and 4) at hospital discharge and at 180 days, cognitive status and quality of life at 180 days, assessment of safety and harm. less thanbrgreater than less thanbrgreater thanDiscussion The TTM trial will investigate potential benefit and harm of 2 target temperature strategies, both avoiding hyperthermia in a large proportion of the out-of-hospital cardiac arrest population.
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| 10. |
- Nielsen, Niklas, et al.
(författare)
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Targeted Temperature Management at 33 degrees C versus 36 degrees C after Cardiac Arrest
- 2013
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Ingår i: New England Journal of Medicine. - 0028-4793. ; 369:23, s. 2197-2206
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundUnconscious survivors of out-of-hospital cardiac arrest have a high risk of death or poor neurologic function. Therapeutic hypothermia is recommended by international guidelines, but the supporting evidence is limited, and the target temperature associated with the best outcome is unknown. Our objective was to compare two target temperatures, both intended to prevent fever. MethodsIn an international trial, we randomly assigned 950 unconscious adults after out-of-hospital cardiac arrest of presumed cardiac cause to targeted temperature management at either 33 degrees C or 36 degrees C. The primary outcome was all-cause mortality through the end of the trial. Secondary outcomes included a composite of poor neurologic function or death at 180 days, as evaluated with the Cerebral Performance Category (CPC) scale and the modified Rankin scale. ResultsIn total, 939 patients were included in the primary analysis. At the end of the trial, 50% of the patients in the 33 degrees C group (235 of 473 patients) had died, as compared with 48% of the patients in the 36 degrees C group (225 of 466 patients) (hazard ratio with a temperature of 33 degrees C, 1.06; 95% confidence interval [CI], 0.89 to 1.28; P=0.51). At the 180-day follow-up, 54% of the patients in the 33 degrees C group had died or had poor neurologic function according to the CPC, as compared with 52% of patients in the 36 degrees C group (risk ratio, 1.02; 95% CI, 0.88 to 1.16; P=0.78). In the analysis using the modified Rankin scale, the comparable rate was 52% in both groups (risk ratio, 1.01; 95% CI, 0.89 to 1.14; P=0.87). The results of analyses adjusted for known prognostic factors were similar. ConclusionsIn unconscious survivors of out-of-hospital cardiac arrest of presumed cardiac cause, hypothermia at a targeted temperature of 33 degrees C did not confer a benefit as compared with a targeted temperature of 36 degrees C. (Funded by the Swedish Heart-Lung Foundation and others; TTM ClinicalTrials.gov number, NCT01020916.)
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