| 3. |
- Iftekhar, Shahriar, et al.
(författare)
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Structural Characterizations of Lanthanum Aluminosilicate Glasses by 27Al and 29Si Solid State NMR
- 2009
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Ingår i: Journal of Non-Crystalline Solids. - : Elsevier BV. - 0022-3093 .- 1873-4812. ; 355:43-44, s. 2165-2174
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the network structures of LaSiAlO glasses by 29Si magic-angle-spinning (MAS) nuclear magnetic resonance (NMR). Their compositions span most of the glass-forming region of the ternary La2O3Al2O3SiO2 system at 1600 °C. The 29Si NMR resonances narrow and become progressively deshielded when Al substitutes for Si in the network, as well as for increasing La-content of the glass, which leads to network depolymerization. We compare experimental and calculated center of gravities of the 29Si NMR peaks, the latter generated from different simplified models for the distributions of Al and Si as well as bridging oxygen (BO) and non-bridging oxygen (NBO) atoms over the networks. The data do not permit accurate quantifications and may only be interpreted in limiting scenarios. However, they indicate that both distributions are essentially randomized, implying a clear deviation of the Al/Si ordering from that according to a Loewenstein Al-avoidance, coupled with a nearly uniform partitioning of the NBO atoms between Al and Si tetrahedra.
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| 4. |
- Newcomer, J. W., et al.
(författare)
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A 24-week, multicenter, open-label, randomized study to compare changes in glucose metabolism in patients with schizophrenia receiving treatment with olanzapine, quetiapine, or risperidone
- 2009
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Ingår i: J Clin Psychiatry. - 1555-2101 .- 1555-2101 .- 0160-6689. ; 70:4, s. 487-99
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This randomized, 24-week, flexible-dose study compared changes in glucose metabolism in patients with DSM-IV schizophrenia receiving initial exposure to olanzapine, quetiapine, or risperidone. METHOD: The hypothesized primary endpoint was change (baseline to week 24) in area under the curve (AUC) 0- to 2-hour plasma glucose values during an oral glucose tolerance test (OGTT); primary analysis: olanzapine versus quetiapine. Secondary endpoints included mean change in AUC 0- to 2-hour plasma insulin values, insulin sensitivity index, and fasting lipids. The first patient enrolled on April 29, 2004, and the last patient completed the study on October 24, 2005. RESULTS: Mean weight change (kg) over 24 weeks was +3.7 (quetiapine), +4.6 (olanzapine), and +3.6 (risperidone). Based on data from 395 patients (quetiapine, N = 115 [mean dose = 607.0 mg/day], olanzapine, N = 146 [mean dose = 15.2 mg/day], and risperidone, N = 134 [mean dose = 5.2 mg/day]), mean change in AUC 0- to 2-hour glucose value (mg/dL x h) at week 24 was significantly lower for quetiapine versus olanzapine (t = 1.98, df = 377, p = .048). Increases in AUC 0- to 2-hour glucose values were statistically significant with olanzapine (+21.9 mg/dL x h, 95% CI = 11.5 to 32.4 mg/dL x h) and risperidone (+18.8 mg/dL x h, 95% CI = 8.1 to 29.4 mg/dL x h), but not quetiapine (+9.1 mg/dL x h, 95% CI = -2.3 to 20.5 mg/dL x h). AUC 0- to 2-hour insulin values increased statistically significantly with olanzapine (+24.5%, 95% CI = 11.5% to 39.0%), but not with quetiapine or risperidone. Reductions in insulin sensitivity index were statistically significant with olanzapine (-19.1%, 95% CI = -27.9% to -9.3%) and risperidone (-15.8%, 95% CI = -25.1% to -5.4%), but not quetiapine. Total cholesterol and low-density lipoprotein levels increased statistically significantly with olanzapine (+21.1 mg/dL, 95% CI = 13.0 to 29.2 mg/dL, and +20.5 mg/dL, 95% CI = 13.8 to 27.1 mg/dL, respectively) and quetiapine (+13.1 mg/dL, 95% CI = 4.3 to 21.9 mg/dL, and +13.3 mg/dL, 95% CI = 6.1 to 20.5 mg/dL, respectively), but not risperidone. Statistically significant increases in triglycerides (+30.9 mg/dL, 95% CI = 10.9 to 51.0 mg/dL), total cholesterol/high-density lipoprotein (HDL) ratio (0.5, 95% CI = 0.2 to 0.8), and triglyceride/HDL ratio (0.3, 95% CI = 0.0 to 0.6) were observed with olanzapine only. CONCLUSION: The results indicate a significant difference in the change in glucose tolerance during 6 months' treatment with olanzapine versus quetiapine, with significant reductions on olanzapine and risperidone, but not quetiapine; these differential changes were largely explained by changes in insulin sensitivity. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00214578.
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