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1.
Chronobiol Int ; 10(1): 63-72, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8443845

RESUMO

In order to determine whether a decrease in the amplitude of heart rate circadian rhythm (HRCR) could represent a chronobiological marker of depression and to answer the question of the possible role of this alteration in the reduction of rapid eye movement sleep latency (REM latency) observed in depression, 22 major depressed patients (DSM III R, Montgomery Asberg Depression Rating Scale) and 11 healthy volunteers entered this study, which included the simultaneous recordings of sleep and heart rate (HR) during two consecutive 24-h periods. After a smoothing procedure, the HR data, obtained from a portable device providing mean HR/min, were computed with the single cosinor method for the classical circadian parameters. We also determined the cosinor fitting index (CFI = percentage to fit). When studied as a single group and compared to the control group, the depressed patients, who had difficulties in sleep initiation and whose REM latencies were within normal limits, were characterized by a dampening of the amplitude HRCR and of the day-night HR difference. This was linked to a lesser increase of HR during the day and a reduced decrease at night. No significant phase modification of HRCR was observed in this group of depressives. In a second step, the depressives were divided into a depressed arrhythmic group (DAG, CFI < 50%, 11 patients) and a depressed rhythmic group (DRG, CFI > 50%, 11 patients) who did not differ on MADRS scores. Even though the amplitude of HRCR was reduced in the DAG only, with HR higher at night and lower during the daytime than for controls, both DAG and DRG significantly differed from controls on those items related to sleep induction and maintenance. In the DAG only was there a tendency toward a reduction of total sleep time and REM sleep time while REM latency was normal. This finding suggests that sleep problems are not responsible for the differences in HRCR parameters between the two depressed groups. These differences in HR and sleep parameters between two groups of similarly depressed patients also suggest that a short REM latency does not systematically imply a disruption of all circadian clocks.


Assuntos
Ritmo Circadiano/fisiologia , Depressão/fisiopatologia , Adulto , Idoso , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Sono/fisiologia , Sono REM/fisiologia
2.
Pest Manag Sci ; 57(12): 1119-26, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11802599

RESUMO

UV irradiation of metoxuron in aerated aqueous solution at 254 nm or between 300 and 450 nm led initially to an almost specific photohydrolysis of the C-Cl bond, resulting in the formation of 3-(3-hydroxy-4-methoxyphenyl)-1,1-dimethylurea (MX3) and hydrogen chloride. The quantum yield was determined to be 0.020 (+/- 0.005) in solutions irradiated at 254 nm. Five minor photoproducts were also identified, in particular the dihydroxydimethoxybiphenyl derivatives resulting from the phototransformation of MX3. Irradiation increased the toxicity of an aqueous solution of metoxuron to the marine bacterium Vibrio fischeri.


Assuntos
Herbicidas/metabolismo , Compostos de Metilureia/metabolismo , Resíduos de Praguicidas/metabolismo , Compostos de Fenilureia/metabolismo , Fotólise/efeitos da radiação , Herbicidas/química , Herbicidas/toxicidade , Hidrólise/efeitos da radiação , Cinética , Espectroscopia de Ressonância Magnética , Compostos de Metilureia/toxicidade , Estrutura Molecular , Resíduos de Praguicidas/química , Resíduos de Praguicidas/toxicidade , Compostos de Fenilureia/química , Compostos de Fenilureia/toxicidade , Testes de Toxicidade , Raios Ultravioleta , Vibrio/efeitos dos fármacos , Água/administração & dosagem
3.
Environ Technol ; 24(8): 1025-30, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14509394

RESUMO

The efficiency of the photocatalytic degradation of dyes and dyeing industry pollutants on immobilized photocatalysts can be improved by addition of hydrogen peroxide, due to its photocatalytic decomposition on TiO2. Experiments were carried out with two azodyes, Acid Orange-7 (AO-7) and Tartrazine (Tart), with 3-nitrobenzenesulfonic add (3-NBSA) which is a chemical intermediate in the dye industry and with real industrial wastewaters, using a thin-film fixed bed reactor. The effect of hydrogen peroxide is only significant for concentrations higher than 5 x 10(-3) M (170 mg l(-1)).


Assuntos
Corantes/química , Peróxido de Hidrogênio/química , Oxidantes/química , Purificação da Água/métodos , Reatores Biológicos , Catálise , Resíduos Industriais , Fotoquímica , Titânio/química , Poluentes Químicos da Água
4.
Ecotoxicol Environ Saf ; 19(3): 327-54, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2194781

RESUMO

Hazard assessment of hydroquinone has been evaluated from bibliographical and original data on the physicochemical properties, the environmental behavior, and the biological effects of this aromatic compound. Hydroquinone, which is produced in large amounts and widely used, must be considered as an environmental contaminant. However, it is not persistent. The ecotoxicity of this molecule, which must be linked to its physicochemical properties, varies from species to species. Its acute and chronic toxicity toward higher terrestrial organisms is moderate. Hydroquinone is estimated to be nonmutagenic by the Ames test but induces chromosome aberrations or karyotypic effects in eucaryotic cells. Carcinogenic and teratogenic potentials have been at present inadequately studied. The study underlines the complementarity of QSAR models and experimental approaches when an attempt is made to obtain ecotoxicological profiles of pollutants.


Assuntos
Poluentes Ambientais/toxicidade , Substâncias Perigosas/toxicidade , Hidroquinonas/toxicidade , Animais , Fenômenos Químicos , Química , Poluentes Ambientais/análise , Poluentes Ambientais/síntese química , Substâncias Perigosas/análise , Substâncias Perigosas/síntese química , Humanos , Hidroquinonas/efeitos adversos , Hidroquinonas/análise , Hidroquinonas/síntese química , Fatores de Risco , Especificidade da Espécie
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