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  • 1
    Electronic Resource
    Electronic Resource
    A new route for the synthesis of phenazine di-N-oxides (1995)
    Springer
    Monatshefte für Chemie 126 (1995), S. 1217-1223 
    Details
    ISSN: 1434-4475
    Keywords: 2-Methyl-3-acetylquinoxaline-1,4-dioxide ; Cinnamoylquinoxaline 1,4-dioxide ; Phenazine 5,10-dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Mehrere Phenazin-5,10-dioxide (7a–d) wurden durch Reaktion von 2-Methyl-3-acetylchinoxalin-1,4-dioxid (2) mit verschiedenen aromatischen Aldehyden oder durch direkte Cyclisierung der Chinoxalinderivate3 in basischem Milieuhergestellt. Zusätzlich wurden die Phenazinderivate8 und9–12 in einer Eintopfreaktion von substituierteno-Nitroanilinen mit verschiedenen Hydroxyverbindungen in Gegenwart von Natriumhypochloritlösung synthetisiert.
    Notes: Summary Several phenazine 5,10-dioxides (7a–d) were prepared by the reaction of 2-methyl-3-acetylquinoxaline 1,4-dioxide (2) with different aromatic aldehydes or by direct cyclization of the quinoxaline cinnamoyl derivatives3 in basic medium. In addition, the phenazine derivatives8 and9–12 were synthesized by a one-pot reaction of substitutedo-nitroanilines with different hydroxy compounds in the presence of sodium hypochlorite solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00824300
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  • 2
    Electronic Resource
    Electronic Resource
    Lactate dehydrogenase and glutamate dehydrogenase activities in the circumventricular organs of rat brain following neonatal monosodium glutamate (1993)
    Springer
    Cellular and molecular life sciences 49 (1993), S. 1092-1094 
    Details
    ISSN: 1420-9071
    Keywords: Monosodium glutamate ; LDH ; GDH ; excitotoxin ; blood-brain barrier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Glutamate (glu) an excitatory neurotransmitter amino acid, is present in high concentrations in the mammalian central nervous system and is the most abundant amino acid in our daily diet. In the present study the activities of lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) were evaluated in the circumventricular organs (CVO) of the brain in 25-day-old rats following MSG administration at a dose of 4 mg/g b.wt during the first ten days of life. The results show the LDH activity increased to 265% of that in the control (p〈0.001), whereas GDH activity was significantly decreased (p〈0.05), The great elevation in LDH, a cytoplasmic marker enzyme, is apparently due to cytoskeletal changes brought about as a consequence of glu toxicity, whereas lowered GDH activity indicates altered glu homostasis in the blood-brain-barrier deficient areas following neonatal exposure to glu.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01929919
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  • 3
    Electronic Resource
    Electronic Resource
    Ventral neural tube cells differentiate into hepatocytes in the chick embryo (1999)
    Springer
    Cellular and molecular life sciences 55 (1999), S. 128-130 
    Details
    ISSN: 1420-9071
    Keywords: Key words. Ventral neural tube cells; chick embryo; hepatocytes; development; liver.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A population of ventral neural tube cells has recently been shown to migrate out of the hind brain neural tube via the vagus nerve and contribute to the developing gastrointestinal tract. Since liver is also innervated by the vagus nerve, we sought to determine if these cells also migrate into the liver. Ventral neural tube cells in the caudal hindbrain of chick embryos were tagged with a replication-deficient retroviral vector containing the LacZ gene on embryonic day 2. Embryos were processed for detection of labeled cells on embryonic day 5 and 11. Labeled cells were seen in the liver on both days and identified as hepatocytes. Previously, it was believed that all hepatocytes develop from the gut endoderm. Results of the present study show an additional source for the formation of liver cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000180050276
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of neonatal monosodium glutamate on the activities of glutamate dehydrogenase and aminotransferases in the circumventricular organs of rat brain (1995)
    Springer
    Amino acids 8 (1995), S. 393-395 
    Details
    ISSN: 1438-2199
    Keywords: Amino acids ; Monosodium glutamate ; Glutamate dehydrogenase ; Aminotransferases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Glutamate (Glu) the major amino acid in mammalian brain and most dietary proteins possesses neurotransmitter as well as neurotoxic properties. We administered monosodium glutamate (MSG) 4 mg/g bwt, sc on postnatal day (PND) 1 through 10 to rats on alternate days or daily and sacrificed them on PND 45 or PND 90 respectively. The activities of glutamate dehydrogenase and aminotransferases were evaluated in the circumventricular organs of brain. Results show that neonatal MSG produces alterations in glutamate metabolism in blood-brain-barrier deficient regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00806557
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  • 5
    Electronic Resource
    Electronic Resource
    The impact of three industrial effluents on submerged aquatic plants in the River Nile, Egypt (1996)
    Springer
    Hydrobiologia 340 (1996), S. 77-83 
    Details
    ISSN: 1573-5117
    Keywords: River Nile ; industrial pollution ; submerged macrophytes ; canonical ordination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The submerged vegetation growing in the drainage channels taking effluent from three factories (two processing sugar cane plus one producing chipboard or paper pulp; and one large fertilizer plant) into the River Nile in Upper Egypt, and in the river itself upstream and downstream of the discharge points, was studied during 1994. The main pollutants from the sugar cane factory effluents comprised organic matter, including carbohydrates; from the fertilizer plant ammonia was the principal pollutant. The study investigated the effect of these different pollutants on aquatic plant standing crop and distribution, in relation to physico-chemical characteristics of water and hydrosoil. In the effluent channels, dominated by large growths of sewage fungus, submerged vegetation was absent, although some emergent vegetation survived. In the most polluted river sites, up to 2 km downstream of discharge points, the flora was restricted to Potamogeton pectinatus L. Elsewhere in the river, a more diverse submerged flora was present, including Ceratophyllum demersum L. and Potamogeton crispus L.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00012737
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  • 6
    Electronic Resource
    Electronic Resource
    Macrophyte functional variables versus species assemblages as predictors of trophic status in flowing waters (1999)
    Springer
    Hydrobiologia 415 (1999), S. 131-138 
    Details
    ISSN: 1573-5117
    Keywords: phosphate ; modelling ; eutrophication ; aquatic plants ; rivers ; irrigation channels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A series of models was developed using functionally-derived variables (mainly based on morphological attributes of freshwater macrophytes) to predict the trophic status of river and associated channel systems. The models were compared with an existing species-assemblage based procedure for predicting British river trophic conditions (the Macrophyte Trophic Ranking scheme, MTR). We compared sites in cooler temperate conditions (in Scotland) and warmer, sub-tropical conditions (in Egypt). In total, we made measurements of 13 traits from 〉600 individual plant specimens of 33 species growing at 42 sites (divided into independent input and test site datasets). N status (as annual mean concentration in water of total oxidised nitrogen, TON) was only very poorly predicted by this approach. However, P (as annual mean concentration in water of soluble reactive phosphate, SRP) was better predicted: both by a model based on MTR (r = −0.585, p〈0.001), and by models using functional attributes of the macrophyte vegetation. River Trophic Status Indicator (RTSI) models based on ranked plant functional group relationship to river water P concentrations (RTSIFG), or field-measured trait sets of the plants (RTSITR) could also individually explain up to about 34% of the variation in P, both for the total dataset and for subsets from Egypt or Scotland alone or for high v. low-flow sites. Combining both types of RTSI measure produced the most powerful predictive model (r = 0.72, p〈0.001), explaining just over half the variability in P.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003833419359
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  • 7
    Electronic Resource
    Electronic Resource
    Topographical Multilevel Single Linkage (1994)
    Springer
    Journal of global optimization 5 (1994), S. 349-358 
    Details
    ISSN: 1573-2916
    Keywords: Global optimization ; multilevel single linkage ; topographs ; graph minima
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract An iterative topographical Multilevel Single Linkage (TMSL) method has been introduced. The approach uses topographical information on the objective function, in particular theg-nearest-neighbour graph. The algorithm uses evenly distributed points from a Halten sequence of uniform limiting density. We discuss the implementation of the algorithm and compare its performance with other well-known algorithms. The new algorithm performs much better (in some cases several times) than the Multilevel Single Linkage method in terms of number of function evaluations but is not quite so competitive with respect to CPU time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01096684
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  • 8
    Electronic Resource
    Electronic Resource
    A Numerical Comparison of Some Modified Controlled Random Search Algorithms (1997)
    Springer
    Journal of global optimization 11 (1997), S. 377-385 
    Details
    ISSN: 1573-2916
    Keywords: Global optimization ; β-distribution ; controlled random search
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper we propose a new version of the Controlled Random Search(CRS) algorithm of Price. The new algorithmhas been tested on thirteen global optimization test problems. Numericalexperiments indicate that the resulting algorithm performs considerablybetter than the earlier versions of the CRS algorithms. The algorithm,therefore, could offer a reasonable alternative to many currently availablestochastic algorithms, especially for problems requiring ’direct search‘type methods. Also a classification of the CRS algorithms is made based on’global technique‘ – ’local technique‘ and the relative performance ofclasses is numerically explored.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008236920512
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  • 9
    Electronic Resource
    Electronic Resource
    Application of Stochastic Global Optimization Algorithms to Practical Problems (1997)
    Springer
    Journal of optimization theory and applications 95 (1997), S. 545-563 
    Details
    ISSN: 1573-2878
    Keywords: Global optimization ; real life problems ; pig liver likelihood function ; many-body potential function ; tank reactor ; optimal control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We describe global optimization problems from three different fields representing many-body potentials in physical chemistry, optimal control of a chemical reactor, and fitting a statistical model to empirical data. Historical background for each of the problems as well as the practical significance of the first two are given. The problems are solved by using eight recently developed stochastic global optimization algorithms representing controlled random search (4 algorithms), simulated annealing (2 algorithms), and clustering (2 algorithms). The results are discussed, and the importance of global optimization in each respective field is focused.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022617804737
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  • 10
    Electronic Resource
    Electronic Resource
    Aspiration Based Simulated Annealing Algorithm (1997)
    Springer
    Journal of global optimization 11 (1997), S. 181-191 
    Details
    ISSN: 1573-2916
    Keywords: Global optimization ; continuous variables ; aspiration value ; simulated annealing ; stochastic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract An aspiration based simulated annealing algorithm for continuousvariables has been proposed. The new algorithm is similar to the one givenby Dekkers and Aarts (1991) except that a kind of memory is introduced intothe procedure with a self-regulatory mechanism. The algorithm has beenapplied to a set of standard global optimization problems and a number ofmore difficult, complex, practical problems and its performance comparedwith that of the algorithm of Dekkers and Aarts (1991). The new algorithmappears to offer a useful alternative to some of the currently availablestochastic algorithms for global optimization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008202703889
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