Dutch studies Subject

The methods EN 1528 1996 and EN 12393 1998 comprise a range of old multiresidue methods of equal status, which are widely accepted throughout Europe. These are, e.g., the Luke method and the German Deutsche Forschungsgemeinschaft (DFG) methods S8 and S19 ° (all based on extraction with acetone), the Association of Official Analytical Chemists (AOAC) method 970.52 (using acetonitrile extraction and liquid-liquid partition combined with Horisil column cleanup) and the Dutch ethyl acetate extraction combined with GPC. All methods have been subjected to inter-laboratory studies, although not with all pesticide/matrix combinations, which would be impossible to achieve. 

Several European investigations have compared the effects of boiled vs. filtered coffee on serum cholesterol. In a study with 101 Dutch men and women17who typically consumed an average of 5.6 cups/day of filtered coffee, investigators assigned subjects randomly to drink 4 to 6 cups/day... 

The research described in this paper was funded by the Dutch Ministry of Social Affairs and Employment. We want to thank the subjects for volunteering to participate in this study. For assistance in the field work we would like to thank Marieke Beelen, Bert Bierman, Marcel de Haan, Ceciel Lansink, and John Matulessy. Usha Soekoe, Roel Engel, and Lambert Leenheers are acknowledged for performing chemical analyses. 

Most polysaccharides used today are of plant origin. However, also bacteria produce polysaccharides. Especially extracellular polysaccharides (eps s) produced by lactic acid bacteria may find application in foods. Lactic acid bacteria are food-grade organisms and the eps s produced offer a wide variety of structures. The presence of eps is considered to contribute greatly to texture and structure of fermented milk products. An exopolysaccharide produced by Lactococcus lactis ssp. cremoris B40 was chosen as a subject of study. The eps was a gift from the Dutch Institute of Dairy Research (NIZO), Ede, the Netherlands. The eps had no gelling properties, could not be precipitated in plates by ethanol or cetylpyridinium chloride and did not show interaction with Congo red. 

To assess in a single session the incidence of the poor-metabolizer phenotypes for sparteine and mephenytoin, and the variability in nifedipine metabolism, in a Dutch population of 172 subjects [20]. A 7.4% incidence of poor metabolizers of sparteine was detected, which is quite similar to that found in other Caucasian populations. For mephenytoin 2.3% of this population was found to poorly metabolize it to para-hydroxymephenytoin. In a similar study in 130 healthy subjects a cocktail of phenytoin, sparteine and nifedipine was administered [22], The results of this study for nifedipine have been presented in Fig. 1, whereas a similar extent of variability in the plasma kinetic (AUC) for phenytoin was observed. Correlations between relevant kinetic and metabolic parameters of the three probe drags were all low and non-significant. None of the data of nifedipine and phenytoin were different between extensive and poor metabolizers of sparteine. Thus the major oxidative metabolic pathways of nifedipine, sparteine and phenytoin are not related to each other. The three compounds can in principle be used... 

Just like in several other European countries, chemistry as a teaching subject was first institutionalized during the seventeenth century in medical faculties of the Dutch universities. Next to that, there were several so-called athenea that prepared for university studies. In the eighteenth century almost all universities and athenea had chairs of chemistry, although often in combination with botany or medicine. After the Napoleonic wars, only three out of five universities were continued by the national government - Leiden, Groningen and Utrecht - and in the course of the nineteenth century only two athenea survived - Amsterdam and Deventer. In 1876 the Atheneum Illustre of Amsterdam was raised to university status. Outside the universities chemistry was practiced mainly by pharmacists, just like abroad. 

Van t Hoff, Jacobus Henricus (1852-1911) Dutch theoretical chemist. Van t Hoff made important contributions to stereochemistry, thermodynamics, the kinetics of chemical reactions and the theory of chemical solutions. In 1874 Van t Hoff initiated the subject of stereochemistry when he postulated that the four chemical bonds which a carbon atom can form are directed toward the corners of a regular tetrahedron. This enabled the phenomenon of optical activity to be understood in terms of the structures of optical isomers. Van t Hoff introduced this idea independently of Joseph le Bel. Many of the contributions of Van t Hoff to thermodynamics, kinetics and solutions were expounded in his book Studies of Chemical Dynamics (1884). This included the application of thermodynamics to chemical equilibrium. He was awarded the first Nobel Prize for chemistry in 1901. 

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