| 1. |
- Abrahamsson, Maria, et al.
(author)
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Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.
- 2008
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In: Inorganic Chemistry. - : ACS. - 0020-1669 .- 1520-510X. ; 47:9, s. 3540-3548
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Journal article (peer-reviewed)abstract
- The structural effect on the metal-to-ligand charge transfer (MLCT) excited-state lifetime has been investigated in bis-tridentate Ru(II)-polypyridyl complexes based on the terpyridine-like ligands [6-(2,2'-bipyridyl)](2-pyridyl)methane (1) and 2-[6-(2,2'-bipyridyl)]-2-(2-pyridyl)propane (2). A homoleptic ([Ru(2)(2)](2+)) and a heteroleptic complex ([Ru(ttpy)(2)](2+)) based on the new ligand 2 have been prepared and their photophysical and structural properties studied experimentally and theoretically and compared to the results for the previously reported [Ru(1)(2)](2+). The excited-state lifetime of the homoleptic Ru-II complex with the isopropylene-bridged ligand 2 was found to be 50 times shorter than that of the corresponding homoleptic Ru-II complex of ligand 1, containing a methylene bridge. A comparison of the ground-state geometries of the two homoleptic complexes shows that steric interactions involving the isopropylene bridges make the coordination to the central Ru-II ion less octahedral in [Ru(2)(2)](2+) than in [Ru(1)(2))(2+). Calculations indicate that the structural differences in these complexes influence their ligand field splittings as well as the relative stabilities of the triplet metal-to-ligand charge transfer ((MLCT)-M-3) and metal-centered ((MC)-M-3) excited states. The large difference in measured excited-state lifetimes for the two homoleptic Ru-II complexes is attributed to a strong influence of steric interactions on the ligand field strength, which in turn affects the activation barriers for thermal conversion from (MLCT)-M-3 states to short-lived (MC)-M-3 states.
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| 2. |
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| 3. |
- Andersson, Niklas, 1970, et al.
(author)
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A gene expression fingerprint of mouse stomach ECL cells.
- 2005
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In: Biochemical and biophysical research communications. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 332:2, s. 404-10
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Journal article (peer-reviewed)abstract
- Many of the endocrine cells in the stomach are poorly characterized with respect to physiological significance. In some cases, the anticipated hormone has not yet been identified. Global gene expression analysis of mouse stomach was performed in an attempt to identify the ECL-cell peptide/protein. Specific functional activation (omeprazole-induced hypergastrinaemia) was used as a tool to generate a gene expression fingerprint of the ECL cells. The proposed fingerprint includes 14 genes, among them six are known to be expressed by ECL cells (=positive controls), and some novel ones, which are likely to be ECL-cell-related. The known ECL-cell-related genes are those encoding histidine decarboxylase, chromogranin A and B, vesicular monoamine transporter 2, synaptophysin, and the cholecystokinin-B receptor. In addition, the fingerprint included five genes, which might be involved in the process of secretion and three ESTs with unknown function. Interestingly, parathyroid hormone-like hormone (Pthlh) was identified as a candidate ECL-cell peptide hormone.
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| 4. |
- Andersson, Niklas, 1970, et al.
(author)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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In: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Journal article (peer-reviewed)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 5. |
- Anevski, Dragi, 1965, et al.
(author)
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A general asymptotic scheme for inference under order restrictions
- 2006
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In: Annals of Statistics. - : Institute of Mathematical Statistics. - 0090-5364. ; 34:4, s. 1874-1930
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Journal article (peer-reviewed)abstract
- Limit distributions for the greatest convex minorant and its derivative are considered for a general class of stochastic processes including partial sum processes and empirical processes, for independent, weakly dependent and long range dependent data. The results are applied to isotonic regression, isotonic regression after kernel smoothing, estimation of convex regression functions, and estimation of monotone and convex density functions. Various pointwise limit distributions are obtained, and the rate of convergence depends on the self similarity properties and on the rate of convergence of the processes considered. © Institute of Mathematical Statistics, 2006.
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| 6. |
- Backmark, Anna, 1979, et al.
(author)
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Affinity tags can reduce merohedral twinning of membrane protein crystals
- 2008
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In: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047 .- 0907-4449. ; D64, s. 1183-1186
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Journal article (peer-reviewed)abstract
- This work presents a comparison of the crystal packing of three eukaryotic membrane proteins: human aquaporin 1, human aquaporin 5 and a spinach plasma membrane aquaporin. All were purified from expression constructs both with and without affinity tags. With the exception of tagged aquaporin 1, all constructs yielded crystals. Two significant effects of the affinity tags were observed: crystals containing a tag typically diffracted to lower resolution than those from constructs encoding the protein sequence alone and constructs without a tag frequently produced crystals that suffered from merohedral twinning. Twinning is a challenging crystallographic problem that can seriously hinder solution of the structure. Thus, for integral membrane proteins, the addition of an affinity tag may help to disrupt the approximate symmetry of the protein and thereby reduce or avoid merohedral twinning.
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| 7. |
- Baxevani, Anastassia, 1969, et al.
(author)
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Fatigue life prediction for a vessel sailing the North Atlantic route
- 2007
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In: Probabilistic Engineering Mechanics. - : Elsevier BV. ; 22:2, s. 159-169
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Journal article (peer-reviewed)abstract
- A method for calculating the wave load induced fatigue damage accumulated by a vessel sailing along the North Atlantic route (NAr) is presented. This method is based on the Palmgren-Miner additive rule and the rainflow cycle (RFC) count. For simplicity, the load the vessel experiences is assumed to be proportional to the encountered significant wave height process, $H_s$. The asymptotically normal character of the nominal damage is proved and used to derive the probability distribution of the fatigue life prediction. The proposed method improves the already existing ones by making use of the information contained in the variance of the fatigue damage accumulated during the voyages. The method is illustrated through numerical examples.
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| 8. |
- Baxevani, Anastassia, 1969, et al.
(author)
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Spatio-temporal statistical modelling of significant wave height
- 2009
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In: Environmetrics. - : Wiley. - 1180-4009 .- 1099-095X. ; 20:1, s. 14-31
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Journal article (peer-reviewed)abstract
- In this paper. we construct a homogeneous spatio-temporal model to describe the variability of significant wave height over small regions of the sea and over short periods of time. Then. the model is extended to a non-homogeneous one that is valid over larger areas of the sea and for time periods of up to 10 h. To validate the proposed model. we reconstruct the significant wave height surface under different scenarios and then compare it to satellite measurements and the C-ERA-40 field. Copyright (C) 2008 John Wiley & Sons, Ltd.
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| 9. |
- Bengtsson, Anders, et al.
(author)
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Uncertainty in fatigue life prediction of structures subject to Gaussian loads
- 2009
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In: Probabilistic Engineering Mechanics. - : Elsevier BV. - 0266-8920 .- 1878-4275. ; 24:2, s. 224-235
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Journal article (peer-reviewed)abstract
- In this paper we shall concentrate on Gaussian (or close to Gaussian) loads acting on a structure. The goal is to compute a measure of risk for fatigue of a component during a specific time period and the so called "safety index" will be used to combine different types of uncertainties. The presented methodology can be applied in a more general situation of environmental loads which properties may vary with time of the year. The load is assumed to be "locally" stationary such that the mean load is constant (and taken to be zero) but the variance of the load can change slowly with time. Non-stationary hierarchical processes, separable into a stationary Gaussian process and a process describing the load amplitude and period, e.g. processes with Pierson-Moskowitz or JONSWAP spectrum, are treated in detail. The variability of a load, relevant for the fatigue accumulation process, will be described by means of rainflow cycles counted in the load. Moreover, common damage intensity approximations are reviewed and evaluated in a simulation study. © 2008 Elsevier Ltd. All rights reserved.
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| 10. |
- Bengtsson, Anders, et al.
(author)
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Uncertainty of estimated rainflow damage for random loads
- 2009
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In: Marine Structures. - : Elsevier BV. - 0951-8339 .- 1873-4170. ; 22:2, s. 261-274
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Journal article (peer-reviewed)abstract
- One way to assess the uncertainty in fatigue damage analysis is to use a so-called safety index. In the computation of such an index the coefficient of variation for the accumulated damage is needed. Employing the rainflow cycle count method for fatigue damage leads to, in most cases, complicated calculations. Here we present a new and simplified method to estimate the coefficient of variation for the accumulated damage when only one sample path of the load is available. Non-stationary, slowly changing, Gaussian loads are given special attention. The approach is illustrated by means of stationary Gaussian loads with nine different spectra, a measured non-Gaussian load, a skewed load and the wave load accumulated during one year in a "seasonally changing environment"
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