Influence of novel lignocellulosic residues in a biobed biopurification system on the degradation of pesticides applied in repeatedly high doses

Background: The biobed is a simple biopurification system used to prevent the point-source pesticide contamination that occurs at farm level. The typical composition of the biomixture used in this system is soil, peat and straw in volumetric proportions of 1:1:2. The principal component is straw due to its positive effects on biological activity and thus pesticide degradation. However, access to straw can be limited in some regions, so it must be replaced by other more readily available lignocellulosic residues. Results: Therefore, two alternate lignocellulosic materials (barley husks and pine sawdust) were evaluated as partial substitutes for straw. The degradation of a repeatedly applied mixture of six pesticides by these alternates was assessed. The microbial respiration and fluorescein diacetate (FDA) hydrolysis activity were also assessed. The results showed that the highest degradation efficiency was found in mixtures containing straw and barley husks. Each biomixtures tested achieved a high degradation (50 to 90%) of all the pesticides used except iprodione. Repeated applications of pesticides resulted in a slowing of the degradation rate of all pesticide types in all biomixtures. FDA activity and microbial respiration were higher in the biomixtures containing barley husks and straw compared to the mixture with pine sawdust, a result consistent with the pesticide degradations observed. Conclusions: This paper demonstrates that the straw in the traditional biomixture can be partially replaced by other lignocellulosic materials to efficiently degrade a mixture of pesticides, even when the pesticides are added in successive applications and high concentrations.

Selection of white-rot fungi to formulate complex and coated pellets for Reactive Orange 165 decolourization

Six strains of white-rot fungi isolated from southern Chile were evaluated for their ergosterol/biomass correlation and ligninolytic potential in solid medium to formulate pellets for Reactive Orange 165 (RO165) decolourization. The fungus Anthracophyllum discolor was selected to formulate complex pellets (fungal mycelium, sawdust, and activated carbon), coated pellets (complex pellet + alginate) and simple pellets (fungal mycelium). The activity of ligninolytic enzymes (laccase, manganese peroxidase, manganese-independent peroxidase, and lignin peroxidase) was evaluated in both the complex and coated pellets in modified Kirk medium, and the morphology of the pellets was studied using scanning electron microscopy (SEM). Complex pellets of A. discolor showed a higher enzymatic production mainly MnP (38 U L-1 at day 15) compared to coated and simple pellets. Examinations using SEM showed that both pellets produced a black core that was entrapped by a layer of fungal mycelium. Decolourization of RO165 was demonstrated with all the pellets formulated. However, the highest and fastest decolourization was obtained with complex pellets (100 percent at day 8). Therefore, complex pellets of A. discolor can be used for the biological treatment of wastewater contaminated with RO165.

Cateterismo uretral: un tema para la reflexión / Urethral catheterism: A subject for the reflection

El presente artículo trata del cateterismo uretral inspirado en acciones de prevención y de cuidado integral a la persona. Se propone una guía técnica para el procedimiento con aportes de otras guías basadas en evidencia, además invita a la reflexión a partir del análisis de los riesgos que implica, especialmente los que tienen que ver con la infección urinaria, importante causa de la infección intrahospitalaria. De esta manera se quiere problematizar el papel y la responsabilidad del profesional de enfermería frente a este procedimiento, subrayando la necesidad de practicarlo de manera consciente, con un conocimiento profundo de las indicaciones, riesgos, manejo y medidas alternas que facilitan la eliminación urinaria. Se hace énfasis en los principios éticos de beneficencia no maleficencia como garantes de la calidad del cuidado de enfermería, expresada en el bienestar integral del paciente y su familia.

Hemorroidectomía con electrobisturí vs láser: estudio prospectivo randomizado / Hemorrhoidectomy with electrocautery versus laser: randomized prospective study

Se presenta un estudio prospectivo randomizado de 40 pacientes, divididos en dos grupos semejantes, a los que se realizó una hemorroidectomía abierta con electrobisturí y con láser de CO2: Los resultados de ambos grupos con respecto a la morbilidad y mortalidad postoperatoria inmediata y tardía fueron similares. Sólo 2 pacientes del grupo control (10 por ciento) presentaron sangrado postoperatorio, y en un paciente de cada grupo (5 por ciento) se observó retardo de cicatrización. No hubo infecciones ni estenosis anal. Se evaluó el dolor postoperatorio utilizando la escala visual análoga del dolor. Los controles se realizaron a las 2, 4, 8 y 24 horas. El grupo láser presentó menos dolor en las primeras 8 horas de la cirugía, pero no hubo diferencias luego de las 24 horas de operados. No hubo diferencias en la necesidad de analgesia extra. La hemorroidectomía láser no presenta ventajas claras en cuanto a morbimortalidad, dolor y evolución con respecto a la cirugía tradicional de las hemorroides

Evaluation of sequential aerated treatment of wastewater from hardboard mill

Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD) was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90 percent except when the inlet COD concentration was lower than 25 g/L.

Água residual proveniente de uma indústria de tabuleiro de fibra dura caracterizada por ter um elevado conteúdo orgânico (15-30 g/L DQO) foi estudada utilizando um sistema arejado seqüêncial de forma a definir uma estratégia de start up. A concentração de DQO na entrada do sistema variou na faixa de 0,5-25 g/L e o tempo de residência hidráulico foi mantido em 5 dias. O sistema seqüêncial proposto reduziu DBO, DQO, SST e fenol sobre 90 por cento quando a concentração de DQO na entrada foi menor a 25 g/L.

Evaluation of different Bradyrhizobium sp strains on nityrogen fixation capacity in two forage legumes

Nineteen avaiable strains of Bradyrhizobium sp were used to test two forage legumes, Crotalaria juncea(Crotalaria) and Cajanus cajans (Guandu) for symbiotic N-fixation ability. Greenhouse experiments were conducted for nine weeks in order to evaluate shoot, root, and nodule dry weight, nodule number, and shoot nitrogen content. Nine strains presented relative nitrogen efficiency (RNE) over 100 per cent with Crotalaria cultivar, whereas only 3 strains were more efficient with Guandu. Strain 633 was the only which presented a high yield with both cultivars. Finally, plant dry weight accumulation followed N accumulation obtaining 0.6757 correlation coefficient for Crotalaria and Guandu, respectively

Parasitosis, nutrición e inmunidad / parasitosis, nutrition and immunity

La interacción entre nutrición, función inmune e infección, funciona en ambos sentidos. La desnutrición deteriora la función inmune y la infección parasitaria es más grave en el paciente desnutrido e inmunodeficiente que en una persona bien nutrida e inmunocompetente, aunque en algunos casos la desnutrición parece proteger al huésped de algunas infecciones. A su vez, la infección parasitaria deteriora el estado nutricional y la función del sistema inmune del huésped. Finalmente, la inmunodeficiencia favorece la infección por determinados parásitos con la subsiguiente pérdida de nutrimentos y mayor afectación del estado general del paciente