RESUMO
In this work, the degradation of sulfamethazine (SMT), sulfadiazine (SMD), and sulfamethoxazole (SMX) by using UV light, UV/H2O2, and UV/S2O8-2 was analyzed. Direct photolysis was studied by varying the lamp power and the solution pH. DFT calculations were carried out to corroborate the efficiency of the degradation as a function of the solution pH. The variation of the apparent rate constant, kap, was determined in the indirect photolysis by employing an experimental Box-Behnken-type response surface design. The results evidenced that SMX can be efficiently degraded by applying UV radiation independent of the operating conditions. Nevertheless, the quantum yields for SMT and SMD were close to zero, indicating a low energy efficiency for their photochemical transformation. The effect of the solution pH showed that the photodegradation of sulfonamides depends both on the amount of radiation absorbed as the electronic density. Calculations based on density functional theory and supported by the quantum theory of atoms in molecules allowed to describe fragmentation patterns in the systems under study, proving the lability of S14-C2, N17-C18, and N22-O22 bonds, for SMT, SMD, and SMX, respectively. From response surface methodology, four statistically reliable equations were obtained to determine the kap value as a function of the system operating conditions. Finally, SO4â¢- radicals proved to have a higher reactivity to degrade SMT and SMD compared with HO⢠radicals regardless of the operating conditions of the system.
Assuntos
Sulfametoxazol , Poluentes Químicos da Água , Teoria da Densidade Funcional , Peróxido de Hidrogênio , Cinética , Oxirredução , Fotólise , Sulfadiazina , Sulfametazina , Raios UltravioletaRESUMO
The current view of the neurobiology of learning and memory suggests that long-term memory (LTM) depends not only on the de novo protein synthesis but also on the synthesis of mRNA even hours after the acquisition of memory, as well as that the regulation of transcription through the histone acetylation is essential for the memory establishment. Our previous studies showed that protein synthesis inhibition around the time of training and 5-7 hours after acquisition in the insular cortex (IC) prevents the consolidation of conditioned taste aversion (CTA), a well-established learning and memory paradigm in which an animal learns to associate a novel taste with nausea. However, the participation of mRNA synthesis and the epigenetic regulation through histone acetylation in this process remains unexplored. In the present study we evaluated the effect of the inhibition of transcription as well as deacetylation of histones at two temporal windows on the consolidation of CTA. Thus, immediately or seven hours after CTA acquisition animals received a microinfusion of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) or MS-275 in the IC, respectively. The present results show that transcription inhibition immediately and 7 h after acquisition impairs the CTA memory consolidation, whereas the inhibition of histone deacetylation strengths this memory at those temporal windows. These findings reveal that CTA memory requires recurrent rounds of transcriptional modulation events in the IC in order to consolidate this memory trace, demonstrating that transcriptional and epigenetic modulation substantially contribute to memory-consolidation-related functions performed by a neocortical area even several hours after memory acquisition.
Assuntos
Córtex Cerebral/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Memória/efeitos dos fármacos , Paladar/efeitos dos fármacos , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Córtex Cerebral/fisiologia , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Masculino , Memória/fisiologia , Memória de Longo Prazo/efeitos dos fármacos , Ratos WistarRESUMO
El empleo del software educativo ha constituido una exigencia en las transformaciones que en la Educación Médica Superior (EMS) en Cuba han tenido lugar para perfeccionar el Proceso de Enseñanza Aprendizaje (PEA). Al respecto el trabajo expone las características más sobresalientes de las tres etapas por las que ha transitado su gestión nacional en cuanto a infraestructura, administración del ciclo de vida del software y gestión del conocimiento. Entre los métodos empíricos más empleados se destaca la observación participante, el análisis documental y la encuesta y entre los teóricos el histórico-lógico, análisis-síntesis e inductivo-deductivo. Los resultados muestran que la gestión del Proceso de Desarrollo del Software Educativo (PDSE) ha constituido una necesidad histórica en el de cursar de la EMS y un proceso en continuo perfeccionamiento(AU)
Educational software has been a need in the transformations of medical superior education to make tuitional process perfect learning, work exposes the more outstanding characteristics of three stages that he has transited for his national steps as to infrastructure, administration of life cycle of the software and steps of knowledge. Enter empiric further methods used participating observation stands out, documentary analysis and the opinion poll and among the theorists the historic logician, analysis synthesis and inductive deductive. Aftermath evidence that the Educative Software Process Development steps has constituted a historic need in the EMS's in the time and a process in continuous perfecting(AU)
Assuntos
Humanos , Masculino , Feminino , Aplicações da Informática Médica , Linguagens de Programação , Software/história , Software , CubaRESUMO
In previous studies, the anxiolytic-like effects of Montanoa tomentosa and Montanoa frutescens were reported in male rats, but the potential anxiolytic-like effects of Montanoa plants during the different phases of the ovarian cycle in rats remain to be explored. The anxiolytic-like effects of the aqueous crude extracts of M. frutescens (25 and 50 mg/kg) and M. grandiflora (25 and 50 mg/kg) in the elevated plus maze were investigated in Wistar rats during the estrous cycle and compared with 2 mg/kg diazepam as a reference anxiolytic drug. To investigate any motor effect (i.e., hyperactivity, no changes, or hypoactivity) associated with the treatments, the rats were evaluated in the open field test. The M. frutescens (25 and 50 mg/kg) and M. grandiflora (50 mg/kg) extracts exerted anxiolytic-like effects during the metestrus-diestrus phase, similar to diazepam, without disrupting spontaneous motor activity. No significant effects of the extracts were detected in either behavioral test during the proestrus-estrus phase, whereas diazepam produced motor hypoactivity in the open field test. These results indicate that the M. frutescens and M. grandiflora extracts possess anxiolytic-like effects that depend on the ovarian cycle phase, supporting the Mexican ancient medicinal use of these plants to ameliorate anxiety disorders.