RESUMO
AIM: The aim of this study was to investigate the effect of plasma-enhanced chemical vapour deposition (PECVD) treatment on selected bacteria and spores and to contribute to the understanding of the synergistic effect of UV-directed plasma. METHODS AND RESULTS: The experiments were conducted on pure cultures of Aspergillus brasiliensis and Escherichia coli and on naturally contaminated pistachios that were exposed to pure oxygen-, pure argon- and to a mixture of oxygen-argon-generated plasma for different treatment times and at different micro-organism concentrations. Optical emission spectroscopy (OES) measurements were performed to observe the active species in the plasma. After exposure, the effectiveness of decontamination was assessed through microbiological techniques by calculating the growth reduction on a logarithmic scale. A treatment time of 30 min resulted in a 3·5 log reduction of A. brasiliensis using pure oxygen or argon, while treatment times of 5 min, 1 min and 15 s resulted in a 5·4 log reduction using a mixture of argon and oxygen (10 : 1 v/v). Treatment times of 1 min and 30 s resulted in a 4 log reduction of E. coli with oxygen and argon, respectively, which led to a complete elimination of the micro-organisms. Two-log reductions of fungi were achieved for pistachios after a treatment time of 1 min. CONCLUSIONS: These results suggest that this newly designed plasma reactor offers good potential applications for the reduction in micro-organisms on heat-sensitive materials, such as foods. The plasma that was generated with Ar/O2 was more effective than that which was generated with pure oxygen and pure argon. SIGNIFICANCE AND IMPACT OF THE STUDY: An improvement in the knowledge about PECVD mechanisms was acquired from the chemical and biological points of view, and the suitability of the method for treating dry food surfaces was demonstrated.
Assuntos
Aspergillus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Pistacia/microbiologia , Gases em Plasma/farmacologia , Esterilização/métodos , Argônio , Temperatura Baixa , Oxigênio/química , Gases em Plasma/química , PressãoRESUMO
En la primera parte de este trabajo, se plantea la problemática actual referente al protagonismo del paciente en la toma de decisiones y los límites que éste y la sociedad en su conjunto imponen a la medicina; en ejercicio de los principios de autonomía y de justicia distributiva. Se analiza la licitud de dichos límites, los modelos de toma de decisiones y los instrumentos válidos para pacientes y médicos, destacando la categorización de pacientes como una ayuda de primer orden en el ejercicio de la práctica hospitalaria. Se analizan, de acuerdo a experiencias previas, las posturas de los médicos, de los pacientes y de sus familias, enfatizando la necesidad de un relacionamiento más armónico que impida las desinteligencias que ocurren frecuentemente entre los distintos protagonistas de la toma de decisiones. En la segunda parte se conceptualizan, desde el punto de vista de la psicología médica, algunos elementos teórico-prácticos tendientes a dotar a los equipos asistenciales que se desempeñan en el área hospitalaria, de los instrumentos que les posibiliten el enfrentamiento con mayor eficacia a las situaciones relacionadas con la toma de decisiones y los límites impuestos a la medicina
Assuntos
Humanos , Tomada de Decisões , Ética Médica , Relações Médico-Paciente , Psicologia Médica , Triagem , Consentimento Livre e Esclarecido , Cuidados para Prolongar a VidaRESUMO
En la primera parte de este trabajo, se plantea la problemática actual referente al protagonismo del paciente en la toma de decisiones y los límites que éste y la sociedad en su conjunto imponen a la medicina; en ejercicio de los principios de autonomía y de justicia distributiva. Se analiza la licitud de dichos límites, los modelos de toma de decisiones y los instrumentos válidos para pacientes y médicos, destacando la categorización de pacientes como una ayuda de primer orden en el ejercicio de la práctica hospitalaria. Se analizan, de acuerdo a experiencias previas, las posturas de los médicos, de los pacientes y de sus familias, enfatizando la necesidad de un relacionamiento más armónico que impida las desinteligencias que ocurren frecuentemente entre los distintos protagonistas de la toma de decisiones. En la segunda parte se conceptualizan, desde el punto de vista de la psicología médica, algunos elementos teórico-prácticos tendientes a dotar a los equipos asistenciales que se desempeñan en el área hospitalaria, de los instrumentos que les posibiliten el enfrentamiento con mayor eficacia a las situaciones relacionadas con la toma de decisiones y los límites impuestos a la medicina (AU)
Assuntos
Humanos , Tomada de Decisões , Ética Médica , Relações Médico-Paciente , Psicologia Médica , Cuidados para Prolongar a Vida , Triagem , Consentimento Livre e EsclarecidoRESUMO
In a previous study by our group with patients having asymptomatic teeth with pulpal necrosis and an associated periapical radiolucent lesion (PN/PL), it was shown that prophylactic administration of penicillin V or erythromycin (high-dose, 1-day regimen) resulted in a low incidence of flare-up (mean = 2.2%) and a low incidence of swelling and pain not associated with flare-up. No hypersensitivity responses occurred, and gastrointestinal side effects were found primarily with the erythromycins. To ascertain whether a single-dose administration of a long-acting 1-gm tablet of the cephalosporin antibiotic cefadroxil would result in a similar outcome, the present study was undertaken with 200 patients having quiescent PN/PL. The patients were randomly given either cefadroxil or erythromycin (base or stearate). Evaluations of flare-up were done 1 day, 1 week, and 2 months after endodontic treatment. A 2.0% flare-up incidence was found, with no statistically significant differences for cefadroxil (1.0%), stearate (2.0%), or base (4.0%). No hypersensitivity responses occurred. Gastrointestinal side effects were found primarily with the erythromycins (19.0%). The results showed that a 1-gm, single-dose regimen of cefadroxil was as effective as erythromycin and penicillin in preventing flare-ups and serious sequelae. A comparative analysis of the data from our first study (no peritreatment antibiotics) and the pooled data from our last three investigations (including the current trial) showed that peritreatment antibiotic coverage significantly reduced flare-ups and serious sequelae after endodontic treatment of asymptomatic PN/PL (p less than 0.001).