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101.
Résumé On a étudié les méthodes pour la détermination du phosphate dans des produits biologiques et on a élaboré une nouvelle méthode basée sur la formation de l'acide phosphomolybdique jaune, qui est photocolorimétré en ultraviolet et milieu hydro-acétonique.La méthode proposée a été vérifiée sur le sang et l'urine, en absence ou en présence de l'étalon du phosphate, l'erreur variant entre 0–1%, avec une valeur moyenne de ± 0,45%.
Study of the microdetermination of phosphate in biological products
Summary A study has been made of the methods for the determination of phosphate in biological products and a new method has been worked out that is based on the formation of yellow/phosphomolybdic acid, which is subjected to photocolorimetry in the ultraviolet region in a water-acetone medium.The proposed procedure has been verified on blood and urine, in the absence or presence of additional phosphate. The error varies between 0 and 1%, with a mean value of ± 0,45%.
Zusammenfassung Die Methoden zur Phosphorbestimmung in biologischen Produkten wurden untersucht und ein neues Verfahren ausgearbeitet, das auf der Bildung von gelber Phosphormolybdänsäure beruht, die in wäßrig-acetonischem Milieu im UV gemessen wird. Dieses Verfahren wurde mit Blut- und Harnproben mit und ohne Zugabe gemessener Phosphatmengen geprüft. Der Fehler beträgt 0 bis 1%, der Mittelwert ± 0,45%.相似文献
102.
M. Badea R. Olar D. Marinescu G. Vasile 《Journal of Thermal Analysis and Calorimetry》2006,85(2):285-288
This paper reports the
investigation of the thermal stability of a series of new complexes with mixed
ligands of the type M(dipy)(C3H3O2)2(H2O)y ((1) M: Mn, y=1; (2) M: Ni, y=2; (3) M: Cu, y=1; (4) M: Zn, y=2; dipy: 2,2’-dipyridine and C3H3O2
is acrylate anion). The thermal behaviour steps were investigated. The thermal
transformations are complex processes according to TG and DTG curves including
dehydration, oxidative condensation of acrylate and thermolysis processes.
The final products of decomposition are the most stable metal oxides. 相似文献
103.
Alkylation of 1H-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole and 1H-7-ethoxycarbonyl-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole using different alkylating agents leads regioselectively to 1-N-alkylated products. The hydrolysis-decarboxylation of 1,6-dimethyl-7-ethoxycarbonyl-pyrazolo[5,1-c][1,2,4]triazole yields a compound identical with that obtained by the direct methylation of 1H-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole. The 1-N-alkylation is confirmed by NMR spectroscopy and mass spectrometry. 相似文献
104.
A screen-printed biosensor for the detection of pesticides in water miscible organic solvents is described based on the use of p-aminophenyl acetate as acetylcholinesterase substrate. The oxidation of p-aminophenol, product of the enzymatic reaction was monitored at 100 mV vs. Ag/AgCl screen-printed reference electrode. Miscible organic solvents as ethanol and acetonitrile were tested. The acetylcholinesterase (AChE) was immobilised on a screen-printed electrode surface by entrapment in a PVA-SbQ polymer and the catalytic activity of immobilised AChE was studied in the presence of different percentages of organic solvents in buffer solution. The sensor shows good characteristics when experiments were performed in concentrations of organic solvents below 10%. No significant differences were observed when working with 1 and 5% acetonitrile in the reaction media. Detection limits as low as 1.91x10(-8) M paraoxon and 1.24x10(-9) M chlorpyrifos ethyl oxon were obtained when experiments are carried out in 5% acetonitrile. 相似文献
105.
Bernd Berchtold Vasile Lozan Paul‐Gerhard Lassahn Christoph Janiak 《Journal of polymer science. Part A, Polymer chemistry》2002,40(21):3604-3614
Nickel(II) and palladium(II) complexes with α‐dioxime ligands dimethylglyoxime, diphenylglyoxime, and 1,2‐cyclohexanedionedioxime represent six new precatalysts for the polymerization of norbornene that can be activated with methylaluminoxane (MAO), the organo‐Lewis acid tris(pentafluorophenyl)borane [B(C6F5)3], and triethylaluminum (TEA) AlEt3. The palladium but not the nickel precatalysts could also be activated by B(C6F5)3 alone, whereas two of the three nickel precatalysts but none of the palladium systems are somewhat active with only TEA as a cocatalyst. It was possible to achieve very high polymerization activities up to 3.2 · 107 gpolymer/molmetal · h. With the system B(C6F5)3/AlEt3, the activation process can be formulated as the following two‐step reaction: (1) B(C6F5)3 and TEA lead to an aryl/alkyl group exchange and result in the formation of Al(C6F5)nEt3?n and B(C6F5)3?nEtn; and (2) Al(C6F5)nEt3?n will then react with the precatalysts to form the active species for the polymerization of norbornene. Variation of the B:Al ratio shows that Al(C6F5)Et2 is sufficient for high activation. Gel permeation chromatography indicated that it was possible to control the molar mass of poly(norbornene)s by TEA or 1‐dodecene as chain‐transfer agents; the molar mass can be varied in the number‐average molecular weight range from 2 · 103 to 9 · 105 g · mol?1. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3604–3614, 2002 相似文献
106.
Emil Dinga Camelia Oprean-Stan Cristina-Roxana Tnsescu Vasile Brtian Gabriela-Mariana Ionescu 《Entropy (Basel, Switzerland)》2021,23(11)
The most known and used abstract model of the financial market is based on the concept of the informational efficiency (EMH) of that market. The paper proposes an alternative which could be named the behavioural efficiency of the financial market, which is based on the behavioural entropy instead of the informational entropy. More specifically, the paper supports the idea that, in the financial market, the only measure (if any) of the entropy is the available behaviours indicated by the implicit information. Therefore, the behavioural entropy is linked to the concept of behavioural efficiency. The paper argues that, in fact, in the financial markets, there is not a (real) informational efficiency, but there exists a behavioural efficiency instead. The proposal is based both on a new typology of information in the financial market (which provides the concept of implicit information—that is, that information ”translated” by the economic agents from observing the actual behaviours) and on a non-linear (more exactly, a logistic) curve linking the behavioural entropy to the behavioural efficiency of the financial markets. Finally, the paper proposes a synergic overcoming of both EMH and AMH based on the new concept of behavioural entropy in the financial market. 相似文献
107.
It is not straightforward to find a new feasible solution when several conic constraints are added to a conic optimization
problem. Examples of conic constraints include semidefinite constraints and second order cone constraints. In this paper,
a method to slightly modify the constraints is proposed. Because of this modification, a simple procedure to generate strictly
feasible points in both the primal and dual spaces can be defined. A second benefit of the modification is an improvement
in the complexity analysis of conic cutting surface algorithms. Complexity results for conic cutting surface algorithms proved
to date have depended on a condition number of the added constraints. The proposed modification of the constraints leads to
a stronger result, with the convergence of the resulting algorithm not dependent on the condition number.
Research supported in part by NSF grant number DMS-0317323. Any opinions, findings, and conclusions or recommendations expressed
in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. 相似文献
108.
Ernö Lindner Vasile V. Cosofret Stefan Ufer Timothy A. Johnson R. Bruce Ash H. Troy Nagle Michael R. Neuman Richard P. Buck 《Fresenius' Journal of Analytical Chemistry》1993,346(6-9):584-588
Summary Ion-sensitive, planar micro-electrode arrays were fabricated by photolithographic microelectronics technology on a flexible polyimide substrate. The steps of the microelectronics processing are summarized. The electrodes were tested in blood serum, whole blood and in the hamstring muscle of anesthetized rabbits. The performance characteristics of planar pH-sensors are compared with commercial glass electrodes. The close correlation of the data are encouraging for further acute and later chronic applications.Dedicated to Professor Dr. Wilhelm Fresenius 相似文献
109.
110.