| Author (s): |
Lavinel G. Ionescu
|
| Title: |
ERNESTO GIESBRECHT, GREAT CHEMICAL EDUCATOR AND FATHER OF BRAZILIAN INORGANIC CHEMISTRY |
| Abstract: |
Ernesto Giesbrecht, Brazil s foremost inorganic chemist, and chemical educator was born in Ponta Grossa, Parana, Brazil in 1921 and passed away in Sao Paulo in 1996. He obtained the Bachelor Degree in Chemistry from the University of Sao Paulo in 1943 and was awarded a Doctor of Science Degree by the same institution in 1947. He worked at the University of Sao Paulo most of his life and published over one hundred and fifty scientific papers dealing with alkaloids, compounds of sulfur, selenium, and tellurium, chemical education, and the chemistry of Lanthanides and actinides. He trained approximately thirty research scientists in inorganic chemistry, which eventually spread chemical education and inorganic chemistry throughout Brazi I. Prof. Ernesto Giesbrecht was a great chemical educator and may be considered the father of Brazilian Inorganic Chemistry.
|
| Keywords: |
History of Chemistry, ActiAides, Lanthanides, Compounds of S, Se, Te .
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| Year: |
1996
|
| Initial page: |
1
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| Final page: |
8
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.4_1996.pdf |
|
|
| Author (s): |
MihaeJa Cheregi; Cristina Matachescu; Danila Moscone; Anton Ciucu
|
| Title: |
GLUCOSE AND LACTATE BIOSENSORS COUPLED WITH MICRODIALYSIS PROBE FOR CONTINUOUS MONITORING |
| Abstract: |
Several microdialysis probes coupled to a microcell, where an amperometric biosensor for glucose or lactate was inserted, have been tested to evaluate the stability of the biosensor response for in vivo monitoring of glucose and lactate levels. Microdialysis probes with a molecular weight cut-off ranging from 6000 to 20000 Daltons (Da) were compared. A good sensitivity, reproducibility, and stability of the signal were noticed for both systems with different biosensors.
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| Keywords: |
glucose, lactate, microdialysis probe, flow through analysis.
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| Year: |
1996
|
| Initial page: |
9
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| Final page: |
17
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.12_1996.pdf |
|
|
| Author (s): |
Marcos Aires de Brito
|
| Title: |
MODELS FOR THE ACTIVE SITE STRUCTURE OF PURPLE ACID PHOSPHATASES |
| Abstract: |
This review article examines the current and most relevant models proposed for purple acid phosphatases (PAPs). It also presents a new possibility for the active site structure of mammalian PAPs based on the work that we and other researchers have done in bioinorganic chemistry.
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| Keywords: |
purple acid phosphatases, model complexes, active site, bioinorganic chemistry. .
|
| Year: |
1996
|
| Initial page: |
19
|
| Final page: |
26
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.22_1996.pdf |
|
|
| Author (s): |
MARIA GREABU, R. OLINESCU
|
| Title: |
HIGH SERUM LIPID PEROXIDES AND THEIR SIGNIFICANCE IN PATIENTS WITH LIVER DEFICIENCY |
| Abstract: |
Various significant levels of lipid peroxides were observed in patients with different liver diseases. The increased values of lipid peroxides might be correlated with the modifications in pathological way of bilirubin, glutamate, pyruvate-transaminase, glutathione, triglycerides, and chemiluminescence. This correlation was observed in the acute hepatic insufficiency such as acute viral hepatitis, hepatic coma, ethylic cyrrhosis. The increase of lipid peroxides in the serum of these patients is related to tissue destructions, cellular membrane lysis, and subsequent release of polyunsaturated fatty acids. The determination of lipid peroxides in liver deficiency might indicate an irreversible liver damage and the failure of the antioxidant systems to exert a protective role.
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| Keywords: |
Lipid peroxidation, Chemiluminescence, Oxidative stress, Liver deficiency.
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| Year: |
1996
|
| Initial page: |
27
|
| Final page: |
33
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.30_1996.pdf |
|
|
| Author (s): |
Rogerio Gomes Rodrigues; Graziela Finger; Paulo Cesar Pereira das Neves
|
| Title: |
USE OF MONTMORILLONITE (SMECTITE) AS CATALYST FOR OLEFIN POLYMERIZATION AND TRANSFORMATION OF SULFUR COMPOUNDS |
| Abstract: |
Acid-activated montmorillonite (smectite) clay was used to eliminate olefins and transform thiophenes and mercaptans present in aromatic BTX (benzene-toluene-xylene) streams from the aromatic extraction unit of COPESUL - Companhia Petroqufmica do Sul. The working temperature of the mineral clay was raised above normally specified values since difficulties were encountered to meet the specification for hydrogen sulfide in xylene and trimethylbenzene. The experimental results showed that montmorillonite (smectite) clay was suitable for olefin elimination and sulfur compounds transformation at higher reaction temperatures (200 °C) and that the useful life for catalytic operations could be prolonged by raising the temperature.
|
| Keywords: |
Montmorillonite (Smectite); clay; olefin polymerization; desulfurization; BTX (benzene-toluene-xylene) streams.
|
| Year: |
1996
|
| Initial page: |
35
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| Final page: |
44
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.37_1996.pdf |
|
|
| Author (s): |
Tudor Rosu; Lidia PARUTA; Anca EMANDI
|
| Title: |
THE ELECIRICAL BEHAVIOUR OF THE MXHgI4 INORGANIC COMBINATION AND SOME STRUCTURAL ALTERATIONS VERSUS THE PRESSURE |
| Abstract: |
In this paper the structural changes of the MXHgI4 -type combinations (M =Ag+, Cu+, Tl+, Pb+2, Cd2+ and x = 1,2) which occur due to pressure (5 -30 MPa) applied on the powder of these complexes are presented. These alterations were confirmed by the X-ray diffraction spectra and by electrital conductibility measurements.
|
| Keywords: |
etraiodomercurates, electrital conductibility, X-ray diffraction, structural alterations..
|
| Year: |
1996
|
| Initial page: |
45
|
| Final page: |
58
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.47_1996.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu; Danil A. R. Rubio; Elizabeth Fatima De Souza
|
| Title: |
MICELLAR CATALYZED HYDROLYSIS OF LITHIUM p-NITROPHENYL ETHYL PHOSPHATE (LiPNEF) AND THE PSEUDO PHASE ION EXCHANGE MODEL |
| Abstract: |
The hydrolysis of lithium p-nitrophenyl ethyl phosphate (LiPNEF) was studied at 25°, 35°, and 45 °C by spectrophotometric techniques in the presence of micelles of cetyltrimethylammonium bromide (CTAB), sodium hydroxide, and salt. The concentration of NaOH used varied from 0,050 to 5,00 M and the NaCl ranged from 0,0050 to 0,030 M. Pseudo-first order rate constants (kw) and second-order rate constants (k2) and activation parameters such as Ea, ΔH≠, ΔG≠, and ΔS≠ were measured. The system was also studied by tensiometric, viscosity, and quasi-elastic light scattering methods. At low concentrations of NaOH (below 0,55 M), the reaction can be explained in terms of conventional models of micellar catalysis, including the pseudo-phase ion exchange model. For a higher concentration of NaOH, conventional models of micellar catalysis are not applicable. In fact, at high hydroxide concentration, the system no longer contains micelles but liquid crystalline mesophases, and a model analogous to phase transfer catalysis appears to be more appropriate.
|
| Keywords: |
Micellar Catalysis, Phosphate Esters, Pseudo Phase Ion Exchange Model.
|
| Year: |
1996
|
| Initial page: |
59
|
| Final page: |
82
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.61_1996.pdf |
|
|
| Author (s): |
Corneliu Oniscu; Adina Dumitrascu; Eugen Horoba; Dan Cascaval
|
| Title: |
SYNTHESIS OF SOME THEOPHYLLINE DERIVATIVES |
| Abstract: |
Eight new theophyllines derived from the methyl esters of chlorosulphonyl-aryloxyalkylcarboxylic acids, with a possible action on the vascular system, have been prepared Their structures have been elucidated by IR, 1H-NMR, and elementary analysis.
|
| Keywords: |
8-substituted theophyllines, theophyllinyl-sulphonyl-phenoxyacetats, phenoxyacetic esters, esters of sulphonamidated aryloxyalkylcarboxylic acids.
|
| Year: |
1996
|
| Initial page: |
83
|
| Final page: |
91
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.85_1996.pdf |
|
|
| Author (s): |
Paulo Irajara Borba Carneiro; Roberto Rittner
|
| Title: |
CARBON-13 NMR OF ALIPHATIC TERTIARY AMIDES |
| Abstract: |
This work presents unpublished Carbon-13 NMR data for eight aliphatic tertiary amides. The substituent chemical shifts of the CONMe2 and CONEt2 groups were determined and can be useful in correlation analysis.
|
| Keywords: |
Carbon-13 NMR, chemical shifts, aliphatic tertiary amides..
|
| Year: |
1996
|
| Initial page: |
93
|
| Final page: |
96
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.94_1996.pdf |
|
|
| Author (s): |
Joseph A. Schufle
|
| Title: |
DUNCAN ARTHUR MACINNES, FOREMOST AMERICAN ELECTROCHEMIST |
| Abstract: |
Duncan Arthur Macinnes, one of the worlds outstanding electrochemists, was born in Salt Lake City, Utah, on Marah 3l, l885, and died on September 23, 1965. He graduated from the University of Utah with a bachelor of science degree in chemical engineering in 1907 and obtained a Ph.D. degree in chemistry from the University of Illinois in 1911. He held positions mainly at M.I.T and the Rockefeller Institute for Medical Research. His most important contributions deal with the determination of transference numbers by the moving boundary method, development of the glass electrode, and experimental confirmation of the Debye-Hllakel Theory.
|
| Keywords: |
Duncan Arthur Macinnes.
|
| Year: |
1996
|
| Initial page: |
97
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| Final page: |
100
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.98_1996.pdf |
|
|
| Author (s): |
Stelian Florea; Anca Nicolae; Ovidiu Maior
|
| Title: |
SYNTHESIS OF NEW BENZO[e]DIBENZOFURO[2,3-b]-OXEPIN-5(14H)-ONES. |
| Abstract: |
The new ring systems, benzo[e]dibenzofuro[2,3-b]oxepin-5(14H)-one and benzo[e]dibenzofuro[2,1-b]oxepin-5(14H)-one were obtained by cyclizing of 2-(2-dibenzoftuyloxymethyl)benzoic acid in the presence of polyphosphoric acid ester.By cyclization of the 2-(1-methoxy-2-dibenzofuryloxymethyl) benzoic acid was obtained benzo[e]dibenzofuro[2,3-b]-oxepin-12-methoxy-5-one with a indubitable structure. The structure of the new compounds was proved by means of 1H-and 13C-NMR spectra.
|
| Keywords: |
Polycyclic heterocycles/Benzodibenzofuro-oxepinones .
|
| Year: |
1996
|
| Initial page: |
101
|
| Final page: |
108
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v4.n4.1996.101_1996.pdf |
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