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- Borg, S, et al.
(författare)
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Structure study of Bi2.5Na0.5Ta2O9 and B2.5Nam-1.5NbmO3m+3 (m=2-4) by neutron powder diffraction and electron microscopy
- 2002
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Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596. ; 167:1, s. 86-96
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Tidskriftsartikel (refereegranskat)abstract
- The crystal structures of Bi2.5Na0.5Ta2O9 and Bi2.5Nam-1.5NbmO3m+3 (m = 3,4) have been investigated.ysis of their neutron powder diffraction by the Rietveld anal patterns (lambda = 1.470 Angstrom). These compounds belong to the Aurivillius phase family and are built up by (Bi2O2)(2+) fluorite layers and (A(m-1)BnO(3m+1))(2-) (m = 2-4) pseudo-perovskite slabs. Bi2.5Na0.5Ta2O9 (m = 2) and Bi2.5Na2.5Nb4O15 (m = 4) crystallize in the orthorhombic space group A2(1)am, Z = 4, with lattice constants of a = 5.4763(4), b = 5.4478(4), c 24.9710 (15) and a = 5.5095(5), b = 5.4783(5), c = 40.553(3) Angstrom, respectively. Bi2.5Na1.5Nb3O12 (m = 3) has been refined in the orthorhombic space group B2cb, Z = 4, with the unit-cell parameters a = 5.5024(7), b = 5.4622(7), and c = 32.735(4) Angstrom. In comparison with its isostructural Nb analogue, the structure of Bi2.5Na0.5Ta2O9 is less distorted and bond valence sum calculations indicate that the Ta-O bonds are somewhat stronger than the Nb-O bonds. The cell parameters a and h increase with increasing m for the compounds Bi2.5Nam-1.5NbmO3m+3 (m = 2-4), causing a greater strain in the structure. Electron microscopy studies verify that the intergrowth of mixed perovskite layers, caused by stacking faults, also increases with increasing m. (C) 2002 Elsevier Science (USA).
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| 3. |
- Vidlund, Mårten, et al.
(författare)
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GLUTAMICS : a randomized clinical trial on glutamate infusion in patients operated for acute coronary syndrome
- 2011
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Glutamate has been claimed to protect the heart from ischemia and to facilitate metabolic and hemodynamic recovery after ischemia. The GLUTAMICS-trial investigated if intravenous glutamate infusion given in association with surgery for acute coronary syndrome can reduce mortality and prevent or mitigate myocardial injury and postoperative heart failure. Methods: In this investigator-initiated prospective, double-blind study 861 patients undergoing surgery for acute coronary syndrome in three Swedish Hospitals were randomly assigned to intravenous infusion of glutamate (n=428) or saline (n=433) perioperatively. The primary endpoint was a composite of postoperative mortality (30 days), perioperative myocardial infarction and left ventricular heart failure on weaning from cardiopulmonary bypass. Results: Thirty-day mortality was 0.9 % in the glutamate group and 1.2% in the control group. Cardiac mortality was 0.2% in the glutamate group and 0.9% the control group. The incidence of the composite primary end point was 7.2% in the glutamate group and 5.8% in the control group. None of these differences were statistically significant. Regarding secondary end points significantly fewer patients in the glutamate group were hemodynamically unstable at completion of surgery (0.3% v 1.8%; p=0.035) or in need of intra-aortic balloon pump on arrival to the intensive care unit (0.0% v 1.2%; p=0.026). In patients with severe unstable angina (CCS class IV; n=475) the incidence of severe circulatory failure according to prespecified criteria was significantly lower in the glutamate group (2.6% v 6.6%; p=0.036). Conclusions: The primary endpoint did not differ significantly between the groups. Regarding secondary end points there were significant differences compatible with a beneficial effect of glutamate on myocardial recovery. (ClinicalTrials.gov Identifier: NCT00489827)
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| 4. |
- Vidlund, Mårten, 1968-, et al.
(författare)
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GLUTAMICS-a randomized clinical trial on glutamate infusion in 861 patients undergoing surgery for acute coronary syndrome
- 2012
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - New York, USA : Elsevier. - 0022-5223 .- 1097-685X .- 1524-0274. ; 144:4, s. 922-
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Glutamate has been claimed to protect the heart from ischemia and to facilitate metabolic and hemodynamic recovery after ischemia. The GLUTAmate for Metabolic Intervention in Coronary Surgery trial investigated whether an intravenous glutamate infusion given in association with surgery for acute coronary syndrome could reduce mortality and prevent or mitigate myocardial injury and postoperative heart failure. less thanbrgreater than less thanbrgreater thanMethods: In the present prospective, triple-center, double-blind study, 861 patients undergoing surgery for acute coronary syndrome were randomly assigned to an intravenous infusion of glutamate (n=428) or saline (n=433) perioperatively. less thanbrgreater than less thanbrgreater thanResults: The incidence of the primary endpoint-a composite of 30-day mortality, perioperative myocardial infarction, and left ventricular heart failure at weaning from cardiopulmonary bypass-was 7.3% versus 5.8% (P=.41) in the glutamate and control groups, respectively. Patients with left ventricular failure at weaning from cardiopulmonary bypass had a shorter median intensive care unit stay (25 vs 92 hours; P=.02) if they were treated with glutamate. In patients with unstable angina (Canadian Cardiovascular Society class IV) undergoing isolated coronary artery bypass grafting (n=458), the incidence of severe circulatory failure according to the prespecified criteria was significantly lower in the glutamate group (1.3% vs 6.9%; P=.004). On multivariate analysis, glutamate infusion was associated with a reduced risk of developing severe circulatory failure (odds ratio, 0.17; 95% confidence interval, 0.04-0.72; P=.02). A relative risk reduction exceeding 50% for developing severe circulatory failure was seen in most risk groups undergoing isolated coronary artery bypass grafting, with those with diabetes a notable exception. less thanbrgreater than less thanbrgreater thanConclusions: The primary endpoint did not differ significantly between the groups. The secondary outcomes and post hoc analyses warrant additional studies with regard to the potential beneficial effect of glutamate on postischemic myocardial recovery.
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