27 research outputs found
Clustering and the hyperbolic geometry of complex networks
Clustering is a fundamental property of complex networks and it is the
mathematical expression of a ubiquitous phenomenon that arises in various types
of self-organized networks such as biological networks, computer networks or
social networks. In this paper, we consider what is called the global
clustering coefficient of random graphs on the hyperbolic plane. This model of
random graphs was proposed recently by Krioukov et al. as a mathematical model
of complex networks, under the fundamental assumption that hyperbolic geometry
underlies the structure of these networks. We give a rigorous analysis of
clustering and characterize the global clustering coefficient in terms of the
parameters of the model. We show how the global clustering coefficient can be
tuned by these parameters and we give an explicit formula for this function.Comment: 51 pages, 1 figur
Butanediol conversion to gamma-hydroxybutyrate markedly reduced by the alcohol dehydrogenase blocker fomepizole.
1,4-Butanediol (BDO) - used as solvent, and abused for its euphoric effects - is converted to gamma-hydroxybutyrate (GHB) by the enzyme alcohol dehydrogenase (ADH). This double-blind, placebo-controlled crossover study with six healthy volunteers is the first to date investigating the role of the ADH inhibitor fomepizole (4MP) in moderating this conversion in humans. Participants received on two different days either intravenous placebo or 15 mg/kg 4MP, followed by oral administration of 25 mg/kg BDO. Pretreatment with 4MP resulted in significantly higher BDO maximal plasma concentration (p=0.001) and AUC (p=0.028), confirming that ADH is the primary pathway for the conversion of BDO to GHB in humans. With 4MP, the mean arterial pressure was significantly lower at 105 minutes compared to baseline (p=0.003), indicating that blood pressure lowering, observed not with a temporal relationship to 4MP administration but after the maximum BDO concentration was reached, may be an intrinsic effect of BDO. This article is protected by copyright. All rights reserved
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Butanediol Conversion to Gamma-Hydroxybutyrate Markedly Reduced by the Alcohol Dehydrogenase Blocker Fomepizole.
1,4-Butanediol (BDO)-used as solvent and abused for its euphoric effects-is converted to gamma-hydroxybutyrate (GHB) by the enzyme alcohol dehydrogenase. This double-blind, placebo-controlled crossover study with six healthy volunteers is the first to date investigating the role of the ADH inhibitor fomepizole (4-methylpyrazole (4MP)) in moderating this conversion in humans. Participants received on two different days either intravenous placebo or 15 mg/kg 4MP followed by oral administration of 25 mg/kg BDO. Pretreatment with 4MP resulted in significantly higher BDO maximal plasma concentration (P = 0.001) and area under the concentration-time curve (AUC; P = 0.028), confirming that ADH is the primary pathway for the conversion of BDO to GHB in humans. With 4MP, the mean arterial pressure was significantly lower at 105 minutes compared to baseline (P = 0.003), indicating that blood pressure lowering, observed not with a temporal relationship to 4MP administration but after the maximum BDO concentration was reached, may be an intrinsic effect of BDO