RESUMO
Slow sand filtration is a common technology providing potable water in rural households across Latin America, Asia and Africa. Two PVC household slow sand filters (HSSF) were operated in continuous (C-HSSF) and intermittent (I-HSSF) flow modes for eight consecutive months. A non-woven blanket was installed on the fine sand top to facilitate cleaning with scheduled maintenance undertaken every 30 days. The efficiency of each HSSF was evaluated via physico-chemical indicators (reduction of turbidity and colour) with biological performance assessed via total coliform and E. coli enumeration post treatment. There were no statistically significant differences between the continuous flow and intermittent flow models for physical-chemical and total coliform reduction parameters. However, when evaluating E. coli, C-HSSF performed better (p = 0.02). The non-woven blanket was subjected to weekly analysis using a Clark-type amperometric microsensor (diameter < 20â µm), which measured dissolved oxygen (DO) concentration in the adherent biofilm. DO microprofiles illustrated a variation in biofilm growth, which were associated with a progressive increase in the HSSF efficiency. The maximum DO depletion value measured during several months of operation showed no significant difference between I-HSSF and C-HSSF (p = 0.98). The microsensor measurements provided unprecedented results in real time. These results can help to understand the efficiency of the filter in relation to the biofilm growth, the dissolved oxygen depletion and turbidity removal.
Assuntos
Água Potável , Purificação da Água , Purificação da Água/métodos , Escherichia coli , Filtração/métodos , Oxigênio , Dióxido de SilícioRESUMO
This study aimed to evaluate the efficiency of four household slow sand filter (HSSF) models for the removal of microorganisms from river water throughout the development of their biological layers (schmutzdecke). Two models were designed to be operated continuously (HSSF-CC and HSSF-CT) and two intermittently (HSSF-ID and HSSF-IF). Filters were fed daily with 48 L pre-treated river water (24â h sedimentation followed by filtration through a non-woven synthetic blanket). Water samples were quantified by coliform group bacteria and analysed by bright field microscopy to visualize the microorganisms. Total coliform reduction was between 1.42 ± 0.59 log and 2.96 ± 0.58 log, with continuous models showing a better performance (p-values < 0.004). Escherichia coli reduction varied from 1.49 ± 0.58 log to 2.09 ± 0.66 log and HSSF-IF, HSSF-CC and HSSF-CT presented a similar performance (p-values > 0.06), slightly better than the one presented by HSSF-ID (p-value=0.04). Microorganisms, such as algae, protozoa and helminths were detected by microscopy in raw water and pre-treated water. Algae were the most significant group in these samples, although they were not visualized by bright field microscopy in the filtered water. Results showed the potential of HSSF in microbiological risk reduction from river water, which increases the range of point-of-use water treatments in rural communities. However, additional studies of the HSSF biological layer must be performed.
Assuntos
Rios , Purificação da Água , Escherichia coli , Características da Família , Filtração/métodos , Água Doce , Dióxido de Silício , Purificação da Água/métodosRESUMO
In this study, disinfection of urban wastewater (UWW) with two solar processes (H2O2 -20 mg/L and photo-Fenton 10 mg/L-Fe2+/20 mg/L-H2O2 at natural water pH) at pilot scale using a 60 L compound parabolic collector reactor for irrigation of two raw-eaten vegetables (lettuce and radish) has been investigated. Several microbial targets (total coliforms, Escherichia coli, Salmonella spp., and Enterococcus spp.) naturally occurring in UWW and 74 organic microcontaminants (OMCs) were monitored. Disinfection results showed no significant differences between both processes, showing the following inactivation resistance order: Salmonella spp. < E. coli < total coliforms < Enterococcus spp. Reductions of target microorganisms to concentrations below the limit of detection (LOD) was achieved in all cases with cumulative solar UV energy per volume (QUV) ranged from 12 to 40 kJ/L (90 min to 5 h). Solar photo-Fenton showed a reduction of 66% of OMCs and solar/H2O2 of 56% in 5 h treatment. Irrigation of radish and lettuce with solar treated effluents, secondary effluents, and mineral water was performed for 6 and 16 weeks, respectively. The presence of bacteria was monitored in surfaces and uptake of leaves, fruit, and also in soil. The bacterial concentrations detected were below the LOD in the 81.2% (lettuce) and the 87.5% (radish) of the total number of samples evaluated. Moreover, uptake of OMCs was reduced above 70% in crops irrigated with solar treated effluents in comparison with secondary effluents of UWW.
Assuntos
Raphanus , Águas Residuárias , Escherichia coli , Peróxido de Hidrogênio , LactucaRESUMO
BACKGROUND: Medical education should prepare students to face a dynamic environment, through competencies that allow them to learn independently. AIM: To evaluate the relationship between self-directed learning and value profile of undergraduate first year students in a medical school in Chile. MATERIAL AND METHODS: Self-Directed Learning Scale and Schwartz's Values Questionnaire were applied to 235 medical students from the University of Concepción, Chile. RESULTS: Self-direction and Security are value types that correlate directly and significantly with the overall scale and with the five subscales of Self-Directed Learning. CONCLUSIONS: In first year medical students ofUniversity of Concepcion, Chile, Self-direction and Security are values that facilitate Self-directed Learning.
Assuntos
Educação Baseada em Competências/métodos , Educação de Graduação em Medicina/métodos , Aprendizagem , Autoavaliação (Psicologia) , Estudantes de Medicina/estatística & dados numéricos , Adolescente , Adulto , Chile , Educação Baseada em Competências/normas , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Estudantes de Medicina/psicologia , Adulto JovemRESUMO
Background: Medical education should prepare students to face a dynamic environment, through competencies that allow them to learn independently. Aim: To evaluate the relationship between self-directed learning and value profile of undergraduate first year students in a medical school in Chile. Material and Methods: Self-Directed Learning Scale and Schwartz's Values Questionnaire were applied to 235 medical students from the University of Concepción, Chile. Results: Self-direction and Security are value types that correlate directly and significantly with the overall scale and with the five subscales of Self-Directed Learning. Conclusions: In first year medical students ofUniversity of Concepcion, Chile, Self-direction and Security are values that facilitate Self-directed Learning.
Assuntos
Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Educação Baseada em Competências/métodos , Educação de Graduação em Medicina/métodos , Aprendizagem , Autoavaliação (Psicologia) , Estudantes de Medicina/estatística & dados numéricos , Chile , Educação Baseada em Competências/normas , Estudos Transversais , Modelos Lineares , Estudantes de Medicina/psicologiaRESUMO
El extracto etanólico de Croton schiedeanus Schlecht, especie medicinal utilizada por la tradición popular en Colombia con fines antihipertensivos, relaja los anillos vasculares de la aorta de ratas Wistar contraídos con fenilefrina (10-6 M, agonista del receptor adrenérgico alfa), en función de la dosis, con una CE50 de 1,3 × 10-5 g/mL. Este efecto es superior al ejercido sobre anillos contraídos con KCl (6 × 10-2 M, activador de canales de calcio dependientes de voltaje) y se reduce, pero no se suprime en anillos vasculares sin endotelio. La vasodilatación se revierte en presencia de azul de metileno (10-4 M, inhibidor de guanilato ciclasa) y L-NAME (10-4 M, inhibidor de óxido nítrico sintasa), en tanto que no se afecta en presencia de propranolol (10-6 M, antagonista del receptor beta), atropina (3 × 10-5 M, antagonista muscarínico) e indometacina (10-6 M, inhibidor de ciclooxigenasa). Además, las contracciones inducidas por CaCl2 (10-5 - 10-2 M, activador de las corrientes de calcio) no se afectan significativamente en presencia del extracto etanólico de C. schiedeanus (5 × 10-5 g/mL). Por otro lado, al efectuar diluciones sucesivas de L-NAME y azul de metileno (hasta 10-14 M) se observa que C. schiedeanus recupera casi totalmente sus efectos vasodilatadores en presencia de L-NAME, pero no en presencia de azul de metileno (91% y 68% de Emax, respectivamente). Además, la potencia y eficacia vasodilatadora inducida por el extracto de C. schiedeanus fue superior a la ejercida por su metabolito activo mayoritario, ayanina (CI50: 1,3 vs. 4,9 × 10-5 g/mL, Emax: 100 vs. 67%). Estos hallazgos sugieren que C. schiedeanus ejerce efectos vasodilatadores vinculados especialmente con la ruta metabólica de guanilato ciclasa y da soporte al uso tradicional de esta especie.
The EtOH extract of Croton shiedeanus Schlecht, medicinal species used by the popular tradition in Colombia for hypertension, relaxes vascular rings of Wistar rat aorta stimulated with phenylephrine (10-6 M, alpha adrenergic receptor agonist), in a dose-depending manner, with an EC50 of 1.3 × 10-5 g/mL. This effect is superior to that exercised over rings stimulated with KCl (6,0 × 10-2 M, voltage-dependent calcium channel activator) and is reduced in vascular rings without endothelium. The vascular relaxation is reversed in the presence of methylene blue (1.0 × 10-4 M, guanylate cyclase inhibitor) and L-NAME (10-4 M, nitric oxide synthase inhibitor), and is not affected in presence of propranolol (10-6 M, beta receptor antagonist), atropine (30 × 10-5 M, muscarinic antagonist) and indomethacin (10-6 M, cyclooxygenase inhibitor). Additionally, the contractions induced by CaCl2 (10-5 - 10-2 M, calcium currents activator) are not affected in the presence of EtOH C. schiedeanus extract (5.0 × 10-5 g/mL). Serial dilutions of L-NAME and methylene blue (until 10-14 M) show that C. schiedeanus recovers almost entirely the vasodilator effect in presence of L-NAME but not in presence of methylene blue (91 versus 68% of Emax, respectively). In addition, the relaxant potency and efficacy of C. schiedeanus is greater than its predominant active metabolite, ayanin (IC50: 1,3 vs. 4,9 × 10-5 g/mL, Emax: 100 vs. 67%). These findings suggest that C. schiedeanus exerts vasodilating effects, particularly related to the metabolic pathway of guanylate cyclase and gives support the traditional use of this species.
RESUMO
OBJECTIVES: To evaluate the changes experienced over 15 years in the prevalence, state of awareness, treatment and control of hypertension, in urban communities of the VIII Region of Chile. METHODOLOGY: In order to ensure an objective analysis in comparison of the indicators, the methodological design used in 1988 was replicated: a representative, non-institutionalized sample, considering age, gender and socio-economic level. Blood pressure was measured using mercury manometers during two visits carried out on different days. Hypertension criteria: systolic blood pressure>or=140 mmHg and/or diastolic blood pressure>or=90 mmHg, or patients under treatment. RESULTS: A sample of 8472 residents was obtained, based on the previously defined stratification. Hypertension prevalence increased from 18.6% in 1988 to 21.7% in 2004. This occurred in all age groups and in both genders. The state of awareness remained stable: 66.9% in 1988 and 66.6% in 2004. The state of treatment increased from 35.6% (1988) to 59.9% (2004), and the state of hypertension control from 7.5 to 30.7%, respectively. CONCLUSION: This study demonstrated an increase in hypertension prevalence from 1988 to 2004. Meanwhile the state of awareness remained stable but there was a significant increase in the state of treatment and control, which were in accordance with public policies and changes in antihypertensive treatment.
Assuntos
Conscientização , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , População Urbana , Chile/epidemiologia , Humanos , Hipertensão/prevenção & controle , PrevalênciaRESUMO
Desde 1997, en el contexto de las políticas públicas de salud a nivel local y nacional, el Hospital Roberto del Río ha desarrollado un programa de apoyo en atención de Salud Primaria (PAAP), cuyos objetivos son: a) Mejorar la integración de la red local de atención de salud, considerando a la atención primaria (AP) como uno de sus componentes estratégicos. b) Mejorar la interrelación del personal de la red, mediante comunicaciones expeditas, solidarias y respetuosas. c) Apoyar la resolutividad de la AP mediante actividades de capacitación continuas y apropiadas. Las actividades específicas orientadas a lograr estos objetivos son: 1) Programa anual de reuniones clínicas quincenales, considerando necesidades de la AP, en el hospital y consultorios. 2) Pasantías de capacitación por las unidades especializadas donde se resuelven las referencias de la AP (duración 5 a 60 días). 3) Sistema vía fax de consultas clínico-epidemiológicas formuladas desde el nivel primario, con respuesta en 1 a 24 horas desde el nivel secundario terciario. 4) Apoyo bibliográfico mediante envío periódico de artículos actualizados apropiados para la atención primaria, y creación de una sección de biblioteca para uso exclusivo de AP, con solicitud por fax y envío por estafeta. 5) Asesoría directa en consultorios, quincenal, por especialistas IRA. Comentario: el programa ha permitido mejorar la integración y resolutividad tendiendo a un desarrollo equilibrado de la red; ha contribuido a la interrelación de los especialistas con el nivel primario y el progreso científico-técnico de la AP, en beneficio de una mejor atención a la población