146 research outputs found
Ion beam induced selfdiffusion in graphite and its dependence on structure and impurities
State-of-the-art of design and operation of power systems with large amounts of wind power, summary of IEA Wind collaboration
An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The task âDesign and Operation of Power Systems with Large Amounts of Wind Powerâ is analysing existing case studies from different power systems.There are a multitude of studies made and ongoing related to cost of wind integration. However, the results are not easy to compare. This paper summarises the results from 15 case studies
Increases in bioactive IGF do not parallel increases in total IGF-I during growth hormone treatment of children born SGA.
BACKGROUND: Some children born small for gestational age (SGA) experience supra-physiological insulin-like growth factor-I (IGF-I) concentrations during GH treatment. However, measurements of total IGF-I concentrations may not reflect the bioactive fraction of IGF-I which reaches the IGF-I receptor at target organs. We examined endogenous IGF-bioactivity using an IGF-I kinase receptor activation (KIRA) assay that measures the ability of IGF-I to activate the IGF-IR in vitro. AIM: To compare responses of bioactive IGF and total IGF-I concentrations in short GH treated SGA children in the North European Small for Gestational Age Study (NESGAS). RESULTS: Bioactive IGF increased with age in healthy pre-pubertal children (n=94). SGA children had low-normal bioactive IGF levels at baseline (-0.12 (1.8 SD), increasing significantly after one year of high-dose GH treatment to 1.1 (1.4) SD, p2SD (mean IGF-I 2.8 SDS), whereas only 15% (n=15) had levels of bioactive IGF slightly above normal reference values. At baseline, bioactive IGF (SDS) was significantly correlated to height (SDS) (r=0.29, p=0.005), in contrast to IGF-I (SDS) (r=0.17, p=0.10). IGF-I (SDS) was inversely correlated to delta height (SDS) after one year of high-dose GH treatment (r=-0.22, p=0.02). CONCLUSION: In contrast to total IGF-I concentrations, bioactive IGF stayed within the normal reference ranges for most SGA children during the first year of GH treatment
Genetic markers of insulin sensitivity and insulin secretion are associated with spontaneous postnatal growth and response to growth hormone treatment in short SGA children: the North European SGA Study (NESGAS).
PURPOSE: The wide heterogeneity in the early growth and metabolism of children born small for gestational age (SGA), both before and during GH therapy, may reflect common genetic variations related to insulin secretion or sensitivity. METHOD: Combined multiallele single nucleotide polymorphism scores with known associations with insulin sensitivity or insulin secretion were analyzed for their relationships with spontaneous postnatal growth and first-year responses to GH therapy in 96 short SGA children. RESULTS: The insulin sensitivity allele score (GS-InSens) was positively associated with spontaneous postnatal weight gain (regression coefficient [B]: 0.12 SD scores per allele; 95% confidence interval [CI], 0.01-0.23; P = .03) and also in response to GH therapy with first-year height velocity (B: 0.18 cm/y per allele; 95% CI, 0.02-0.35; P = .03) and change in IGF-1 (B: 0.17 SD scores per allele; 95% CI, 0.00-0.32; P = .03). The association with first-year height velocity was independent of reported predictors of response to GH therapy (adjusted P = .04). The insulin secretion allele score (GS-InSec) was positively associated with spontaneous postnatal height gain (B: 0.15; 95% CI, 0.01-0.30; P = .03) and disposition index both before (B: 0.02; 95% CI, 0.00-0.04; P = .04) and after 1 year of GH therapy (B: 0.03; 95% CI, 0.01-0.05; P = .002), but not with growth and IGF-1 responses to GH therapy. Neither of the allele scores was associated with size at birth. CONCLUSION: Genetic allele scores indicative of insulin sensitivity and insulin secretion were associated with spontaneous postnatal growth and responses to GH therapy in short SGA children. Further pharmacogenetic studies may support the rationale for adjuvant therapies by informing the mechanisms of treatment response.This study was funded by a research grant from The Danish Council for
Independent Research/ Medical Sciences and a research grant from Novo Nordisk A/S.This is the accepted manuscript. The final version is available at http://dx.doi.org/10.1210/jc.2014-3469
Compound-Specific Chlorine Isotope Analysis: A Comparison of Gas Chromatography/Isotope Ratio Mass Spectrometry and Gas Chromatography/Quadrupole Mass Spectrometry Methods in an Interlaboratory Study
Proteolytic Activities of Oral Bacteria on ProMMP-9 and the Effect of Synthetic Proteinase Inhibitors
Tissue reactions to bacteria lead to proinflammatory reactions involving matrix metalloproteinases (MMPs). Synthetic protease inhibitors may offer new possibilities to regulate bacterial proteases. We investigated proteolytic activities of certain periodontal bacteria, their effects on the latent proMMP-9, and the effects of synthetic MMP inhibitors and a serine protease inhibitor Pefabloc. The strains studied were Porphyromonas gingivalis, Prevotella intermedia, Peptostreptoccus micros, Prevotella nigrescens, Fusobacterium nucleatum, and 5 Aggregatibacter actinomycetemcomitans serotypes. Their gelatinolytic activities and the effects of certain synthetic MMP inhibitors and Pefabloc were analyzed by zymography. Bacterial effects on proMMP-9 conversion were investigated by Western immunoblot. All investigated periodontal bacteria produced gelatinolytic cell-bound and extracellular proteinases which could fragment latent proMMP-9, suggesting co-operative processing cascades in oral tissue remodeling. A. actinomycetemcomitans produced the weakest gelatinolytic activity. Synthetic proteinase inhibitors exhibited slight but clear reductive effects on the bacterial proteolytic activities. We conclude that targeted anti-proteolytic treatment modalities against bacterial-host proteolytic cascades can be developed
Adiposity in Children Born Small for Gestational Age Is Associated With ÎČ-Cell Function, Genetic Variants for Insulin Resistance, and Response to Growth Hormone Treatment.
BACKGROUND: Genetic susceptibility to insulin resistance is associated with lower adiposity in adults. Insulin resistance, and therefore adiposity, may alter sensitivity to GH. We aimed to determine the relationship between adiposity, genetic susceptibility to insulin resistance or insulin secretion, and response to GH treatment in short children born small for gestational age (SGA). METHODS: In 89 short prepubertal SGA children (age, 6.2 ± 1.6 y; 55 boys) treated with GH for 1 year in a multicenter study, body fat percentage was estimated at baseline and 1 year using dual-energy x-ray absorptiometry. The main outcome measures were treatment-related changes in height, IGF-1 standard deviation score, insulin sensitivity, insulin secretion, and disposition index. Combined multiallele gene scores based on single nucleotide polymorphisms with known associations with lower insulin sensitivity (gene scores for insulin resistance [GS-InRes]) and insulin secretion (gene scores for insulin secretion [GS-InSec]) were analyzed for their relationships with adiposity. RESULTS: Mean percentage body fat at baseline was low compared to normative data (P = .045) and decreased even further on GH treatment (baseline vs 1-year z-scores, -0.26 ± 1.2 vs -1.23 ± 1.54; P < .0001). Baseline percentage body fat was positively associated with IGF-1 responses (p-trends = .042), first-year height gains (B [95% confidence interval], 0.61 cm/y [0.28,0.95]; P < .0001), insulin secretion at baseline (p-trends = .020) and 1 year (p-trends = .004), and disposition index at 1 year (p-trends = .024). GS-InRes was inversely associated with body mass index (-0.13 SD score per allele [-0.26, -0.01]; P = .040), body fat (-0.49% per allele [-0.97, -0.007]; P = .047), and limb fat (-0.81% per allele [-1.62, 0.00]; P = .049) at baseline. During GH treatment, GS-InRes was related to a lesser decline in trunk fat (0.38% per allele [0.16, 0.59]; P = .001) and a higher trunk-limb fat ratio at 1 year (0.04 per allele [0.01, 0.08]; P = .008). GS-InSec was positively associated with truncal fat (0.36% per allele [0.09, 0.63]; P = .009). CONCLUSIONS: Adiposity in SGA children has favorable effects on GH sensitivity and glucose metabolism. The associations with multiallele scores support a causal role of insulin resistance in linking lesser body fat to reduced sensitivity to exogenous GH.This study was funded by research grants from the Danish Council for Independent Research/Medical Sciences and Novo Nordisk A/S. The research work was also supported by International Center for Research and Research Training in Endocrine Disrupting Effects on Male Reproduction and Child Health (EDMaRC), Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Denmark.This is the author accepted manuscript. The final version is available from Endocrine Society via http://dx.doi.org/10.1210/jc.2015-301
Strategies for continuous balancing in future power systems with high wind and solar shares
The use of wind power has grown strongly in recent years and is expected to continue to increase in the coming decades. Solar power is also expected to increase significantly. In a power system, a continuous balance is maintained between total production and demand. This balancing is currently mainly managed with conventional power plants, but with larger amounts of wind and solar power, other sources will also be needed. Interesting possibilities include continuous control of wind and solar power, battery storage, electric vehicles, hydrogen production, and other demand resources with flexibility potential. The aim of this article is to describe and compare the different challenges and future possibilities in six systems concerning how to keep a continuous balance in the future with significantly larger amounts of variable renewable power production. A realistic understanding of how these systems plan to handle continuous balancing is central to effectively develop a carbon-dioxide-free electricity system of the future. The systems included in the overview are the Nordic synchronous area, the island of Ireland, the Iberian Peninsula, Texas (ERCOT), the central European system, and Great Britain
Identification of a Shared Genetic Susceptibility Locus for Coronary Heart Disease and Periodontitis
Recent studies indicate a mutual epidemiological relationship between coronary heart disease (CHD) and periodontitis. Both diseases are associated with similar risk factors and are characterized by a chronic inflammatory process. In a candidate-gene association study, we identify an association of a genetic susceptibility locus shared by both diseases. We confirm the known association of two neighboring linkage disequilibrium regions on human chromosome 9p21.3 with CHD and show the additional strong association of these loci with the risk of aggressive periodontitis. For the lead SNP of the main associated linkage disequilibrium region, rs1333048, the odds ratio of the autosomal-recessive mode of inheritance is 1.99 (95% confidence interval 1.33â2.94; Pâ=â6.9Ă10â4) for generalized aggressive periodontitis, and 1.72 (1.06â2.76; Pâ=â2.6Ă10â2) for localized aggressive periodontitis. The two associated linkage disequilibrium regions map to the sequence of the large antisense noncoding RNA ANRIL, which partly overlaps regulatory and coding sequences of CDKN2A/CDKN2B. A closely located diabetes-associated variant was independent of the CHD and periodontitis risk haplotypes. Our study demonstrates that CHD and periodontitis are genetically related by at least one susceptibility locus, which is possibly involved in ANRIL activity and independent of diabetes associated risk variants within this region. Elucidation of the interplay of ANRIL transcript variants and their involvement in increased susceptibility to the interactive diseases CHD and periodontitis promises new insight into the underlying shared pathogenic mechanisms of these complex common diseases
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