Search results for "RELATION"

Age-dependent differences in the effect of phenprocoumon on the vitamin K1-epoxide cycle in rats

1980

Abstract The anticoagulant activity and the pharmacokinetics of phenprocoumon as well as the effect of phenprocoumon on the vitamin K1-epoxide cycle in younger (12 weeks) and older (36 weeks) male inbred Lewis rats has been examined in a study of the mechanism responsible for the increase in the responsiveness to oral anticoagulant drugs (OAD's) with increasing age. After a single i.v.-dose of phenprocoumon (0†355 mg kg−1 the anticoagulant effect obtained was greater in older than in younger rats. There were no differences between younger and older rats in the rate of elimination, volume of distribution and in the free fraction and free concentration values of phenprocoumon in plasma and li…

Comparative assessment of the toxicology of vitamin A and retinoids in man.

1989

As the title implies, any assessment of the toxic effects of vitamin A derivatives must distinguish between vitamin A in the truest sense, i.e. retinol, and retinoic acid and its synthetic derivatives. Just as no single description is universally applicable to the mode of action of vitamin A derivatives, so too do their toxic effects defy generalization. The recommendation made in 1982 by IUPAC [Eur. J. Biochem., 129 (1989) 1] to designate all derivatives with the typical structure of the vitamin as being retinoids may be chemically logical and correct but, when it comes to describing the effects and side-effects of vitamin A derivatives, it leads to misunderstandings. Retinol, which is fre…

Part-of-Speech Induction by Singular Value Decomposition and Hierarchical Clustering

2006

Part-of-speech induction involves the automatic discovery of word classes and the assignment of each word of a vocabulary to one or several of these classes. The approach proposed here is based on the analysis of word distributions in a large collection of German newspaper texts. Its main advantage over other attempts is that it combines the hierarchical clustering of context vectors with a previous step of dimensionality reduction that minimizes the effects of sampling errors.

Optimal configuration for size-based burst assembly algorithms at the edge node for video traffic transmissions over OBS networks

2008

Optical burst switching (OBS) has been proposed to be a technology for implementing the next generation optical Internet. In this architecture, burst assembly algorithms have an important influence in the pattern traffic that characteristic this sort of optical networks. On the other hand, traffic coming from new applications (such as video on demand, Voice over IP, online gaming or Grid computing) that have real time and bandwidth constraints, has been experimented a rapid increment. Consequently, we consider important to evaluate the performance of traffic from real time applications over OBS networks. In this paper, we evaluate the effects of implementing a size-based burst assembly sche…

Structure-dynamics-function relationships in Asian elephant (Elephas maximus) myoglobin. An optical spectroscopy and flash photolysis study on functi…

1993

In this work we report the thermal behavior (10–300 K) of the Soret band lineshape of deoxy and carbonmonoxy derivatives of Asian elephant (Elephas maximus) and horse myoglobins together with their carbon monoxide recombination kinetics after flash photolysis; the results are compared to analogous data relative to sperm whale myoglobin. The Soret band profile is modeled as a Voigt function that accounts for the coupling with high and low frequency vibrational modes, while inhomogeneous broadening is taken into account with suitable distributions of purely electronic transition frequencies. This analysis makes it possible to isolate the various contributions to the overall lineshape that; in…

La relation à la marque du Z consommateur : une étude exploratoire des causes de détachement

2021

Beyond GDP: an analysis of the socio-economic diversity of European regions

2019

International audience; This paper aims to analyze the socioeconomic diversity of the European Union (EU-28) regions from a dynamic perspective. For that purpose, we combine a series of exploratory space-time analysis approaches to multiple Factor Analysis (MFA) applied to a large range of indicators collected at the NUTS-2 level for the period 2000–2015 for the EU-28. First, we find that the first factor of MFA, interpreted as economic development (ECO-DEV), is spatially clustered and that a moderate convergence process is at work between European regions from 2000 to 2015. Second, when comparing these results with those obtained for Gross Domestic Product (GDP) per capita, we show that th…

Modulation of voltage-gated Na+ and K+ channels by pumiliotoxin 251D: A “joint venture” alkaloid from arthropods and amphibians

2008

Abstract Certain amphibians provide themselves with a chemical defense by accumulating lipophilic alkaloids into skin glands from dietary arthropods. Examples of such alkaloids are pumiliotoxins (PTXs). In general, PTXs are known as positive modulators of voltage-gated sodium channels (VGSCs). Unlike other PTXs, PTX 251D does not share this characteristic. However, mice and insect studies showed that PTX 251D is highly toxic and to date the basis of its toxicity remains unknown. In this work, we searched for the possible target of PTX 251D . The toxin was therefore made synthetically and tested on four VGSCs (mammalian rNa v 1.2/β 1 , rNa v 1.4/β 1 , hNa v 1.5/β 1 and insect Para/tipE ) and…

Retention pharmacokinetic and pharmacodynamic parameter relationships of antihistamine drugs using biopartitioning micellar chromatography

2001

Abstract Antihistamines are drugs which act by competitive inhibition of the H1 or H2 histamine receptors. Little has been known about their clinical pharmacokinetics and biological responses until the last few years. In this paper, we propose quantitative retention–activity relationship, QRAR, models based on the retention data of antihistamines in a biopartitioning micellar chromatography (BMC) system using a Brij35 mobile phase for describing pharmacokinetic parameters such as half-life and volume of distribution, or the pharmacodynamic parameters, therapeutic plasma levels, lethal doses and drug-receptor dissociation constant. The predictive ability of these models is statistically vali…

Digitalisation of municipal healthcare collaboration with volunteers: a case study applying normalization process theory

2021

Abstract Background Increasing use of volunteers in healthcare requires structured collaboration between healthcare services and volunteers. The aim of this research was to explore critical issues and strategies in the implementation process of a digital solution for collaboration with and coordination of volunteers in municipal healthcare services. Methods Qualitative data collection was used to study implementation of a digital system for collaboration with volunteers in three Norwegian municipalities. Three rounds of interviews were conducted with healthcare employees from a volunteer centre and from municipality healthcare units in three municipalities: before implementation, and 6 and …