Uso de quitina e quitosana como adsorventes de amônia de efluentes aquícolas: revisão de literatura / Use of chitin and quitosan as adsorvents of ammonia of aquaculture effluents: a literature review / Uso de quitina y quitosana como adsorbentes de amonia de efluentes acuícolas: revisión de literatura

Os resíduos provenientes da aquicultura são derivados da ração e da excreção dos peixes e podem estar sedimentados, suspensos ou dissolvidos, ocasionando elevados valores de DBO, DQO, nitrogênio e fósforo. A produção de camarões no Brasil tem gerado elevadas quantidades de resíduos sólidos, tendo em vista que os exoesqueletos dos camarões correspondem a cerca de 40% do seu peso total, resultando num forte impacto ambiental. Diversas pesquisas envolvendo a quitina estão sendo desenvolvidas na área de tratamento de água, devido principalmente a sua capacidade de formar filme, sendo utilizada em sistemas filtrantes. Este polissacarídeo também pode ser utilizado como agente floculante no tratamento de efluentes, como adsorvente na clarificação de óleos, e principalmente na produção de quitosana. Atualmente a quitosana possui aplicações multidimensionais, desde áreas como a nutrição humana, biotecnologia, ciência dos materiais, indústria farmacêutica, agricultura, terapia genética e proteção ambiental. A quitosana é muito eficiente na remoção de poluentes em diferentes concentrações. Apresenta alta capacidade e grande velocidade de adsorção, boa eficiência e seletividade tanto em soluções que possuem altas ou baixas concentrações. O uso da biotecnologia, através do processo de adsorção utilizando adsorventes naturais e baratos, como a quitina e quitosana, minimiza os impactos ambientais da aquicultura tanto em relação aos provocados pelo lançamento de efluentes no meio ambiente quanto aos causados pelo descarte inadequado dos resíduos do processamento de camarões.(AU)

Aquaculture residues are derived from fish feed and excretion and may be sedimented, suspended or dissolved, resulting in high BOD, COD, nitrogen and phosphorus values. Shrimp production in Brazil has generated high amounts of solid waste, since shrimp exoskeletons account for about 40% of their total weight, resulting in a strong environmental impact. Several researches involving chitin are being developed in the area of water treatment, mainly due to its ability to form film, being used in filter systems. This polysaccharide can also be used as a flocculating agent in the treatment of effluents, as an adsorbent in the clarification of oils, and especially in the production of chitosan. Currently, chitosan has multidimensional applications, from areas such as human nutrition, biotechnology, materials science, pharmaceutical industry, agriculture, gene therapy and environmental protection. Chitosan is very efficient in the removal of pollutants at different concentrations. It presents high capacity and high adsorption velocity, good efficiency and selectivity both in solutions that have high or low concentrations. The use of biotechnology, through the adsorption process using natural and cheap adsorbents such as chitin and chitosan, minimizes the environmental impacts of aquaculture both in relation to those caused by the release of effluents into the environment and those caused by the inappropriate disposal of processing residues of shrimps.(AU)

Los residuos procedentes de la acuicultura se derivan de la ración y de la excreción de los peces y pueden estar sedimentados, suspendidos o disueltos, ocasionando elevados valores de DBO, DQO, nitrógeno y fósforo. La producción de camarones en Brasil ha generado grandes cantidades de residuos sólidos, teniendo en cuenta que los exoesqueletos de los camarones corresponden a cerca del 40% de su peso total, resultando en un fuerte impacto ambiental. Varias investigaciones involucrando la quitina se están desarrollando en el área de tratamiento de agua, debido principalmente a su capacidad de formar película, siendo utilizada en sistemas filtrantes. Este polisacárido también puede ser utilizado como agente floculante en el tratamiento de efluentes, como adsorbente en la clarificación de aceites, y principalmente en la producción de quitosana. Actualmente la quitosana posee aplicaciones multidimensionales, desde áreas como la nutrición humana, biotecnología, ciencia de los materiales, industria farmacéutica, agricultura, terapia genética y protección ambiental. La quitosana es muy eficiente en la eliminación de contaminantes en diferentes concentraciones. Presenta alta capacidad y gran velocidad de adsorción, buena eficiencia y selectividad tanto en soluciones que poseen altas o bajas concentraciones. El uso de la biotecnología, a través del proceso de adsorción utilizando adsorbentes naturales y baratos, como la quitina y quitosana, minimiza los impactos ambientales de la acuicultura tanto en relación a los provocados por el lanzamiento de efluentes en el medio ambiente en cuanto a los causados por el descarte inadecuado de los residuos del procesamiento de camarones.(AU)

Embolización de colaterales portosistémicas espontáneas como tratamiento de la encefalopatía hepática refractaria / Embolization of spontaneous portosystemic shunts as treatment for refractory hepatic encephalopathy

BACKGROUND: Hepatic encephalopathy (HE) is a common complication of cirrhosis associated with a reduced survival. The presence of high-flux spontaneous porto-systemic shunts can induce HE even in patients with preserved liver function. AIM: To evaluate the effect of spontaneous porto-systemic shunt embolization (SPSE) over HE and its long-term evolution. MATERIAL AND METHODS: Retrospective analysis of 11 patients (91% males) with severe HE non-responsive to medical treatment in whom a SPSE was performed. The grade of HE (employing West Haven score), survival, MELD and Child-Pugh score, ammonia levels, degree of disability (employing the modified Rankin scale (mRs)) were evaluated before and at thirty days after procedure. RESULTS: The most common etiology found was non-alcoholic steatohepatitis (63.6%). A reduction of at least two score points of HE was observed in all patients after thirty days. There was a significant reduction on median (IQR) West Haven score from 3 (2-3) at baseline to 1 (0-1) after the procedure (p < 0.01). Twelve months survival was 63.6%. There was a decrease in median ammonia level from 106.5 (79-165) (ug/dL) to 56 (43-61) after SPSE (p = 0.006). The median mRS score before and after the procedure was 3 (3-5) and 1 (1-2.5), respectively (p < 0.01). Conclusions: According to our experience, SPSE is a feasible and effective alternative to improve HE and functionality of patients with refractory EH.

Ammonia levels during broiler rearing cycle

The evaluated ammonia volatilization rates and its association with humidity, temperature, and pH in broiler litter in conventional and dark house rearing systems. Evaluations were performed at 0.01, 1.00, and 1.50 m high, using a completely randomized design, at a weekly frequency for 12 weeks­from the sanitary void to the end of the 42-day cycle. Litter temperature had no significant difference for different types of house. Humidity and pH levels varied according to houses and evaluation periods. No ammonia volatilization was detected during initial periods. However, up from the 21st day of rearing, rates started to increase, showing higher concentrations at 0.01 m height. At 1.00 and 1.50 m, values around 20 mL·m­3, were obtained and considered an acceptable exposure level for the broilers and employees directly working in this sector. Yet, broiler breeders should target lower levels due to environmental impacts.

Ammonia gas for bacterial control in poultry litter / Gás amônia para controle bacteriano em cama aviária

The current techniques used in the disinfection of reused poultry litter, such as lime addition, windrowing and plastic cover on the surface, do not guarantee the elimination of pathogenic microorganisms, causing damage to the environment and animal health. Gram negative bacteria, i.e., Salmonella and Escherichia coli, can be transmitted from one batch to another through reused litter, causing health damage to broilers and humans that consume food contaminated by these agents. Our study assessed the effectiveness of the methods plastic cover on the surface (PCS) and plastic cover on the surface with ammonia gas injection (PCSAI) in the control of Gram negative bacteria. The results obtained, both in laboratory conditions (Experiment 1) and in the field (Experiment 2), demonstrate that the method PCSAI with 0.22% ammonia gas had a significant reduction (P<0.05) of Gram negative bacteria in the period of 48 hours This new methodology for disinfecting poultry litter will allow its reuse in a practical and safe way, improving the preservation of the environment, of the health of broilers and consumers of poultry products.

O reaproveitamento de camas aviárias na criação de frangos de corte é uma prática muito utilizada no Brasil. Essa prática reduz custos de produção e contribui na conservação do meio ambiente. As técnicas atuais utilizadas na desinfecção de camas aviárias reaproveitadas, como adição de cal, enleiramento e lona na superfície, não garantem a eliminação de microrganismos patogênicos porque não geram quantidade suficiente de amônia. O gás amônia, em concentrações elevadas, tem efeito biocida. Bactérias Gram negativas, como as Salmonelas e Escherichia coli, podem ser transmitidas de um lote para outro através do reaproveitamento da cama, ocasionando prejuízos para a saúde das aves e dos humanos que consomem alimentos contaminados por estes agentes. Este trabalho avaliou a eficácia do método lona na superfície com injeção de gás amônia no controle de microrganismos Gram negativos. Os resultados obtidos demostraram que esse método controlou os microrganismos Gram negativos num período de 48 horas em camas de frangos de corte reaproveitadas. Assim, essa nova metodologia de desinfecção de camas de aviário permitirá sua reutilização de forma prática e segura, melhorando a saúde das aves e dos consumidores dos produtos avícolas.

Calidad del aire interior mediante indicadores ecológicos y sociales asociados a la inmisión de material particulado (PM10) en la zona este 2 / Indoor air quality through ecological and social indicators associated with the immission of particulate matter (PM10) in the eastern zone 2

El material particulado (PM) es uno de los contaminantes más importantes presentes en el aire, representando un riesgo medioambiental para la salud. Las partículas con un diámetro de 10 micrones o menos (PM10), al ser inhalables, pueden penetrar y alojarse profundamente en los pulmones, contribuyendo al riesgo de desarrollar enfermedades cardiovasculares y respiratorias, así como cáncer de pulmón, enfermedades mentales, dermatitis, daño ocular e incluso al aumento en las tasas de mortalidad. Se estableció como objetivo determinar la calidad del aire interior asociada a la inmisión de material particulado (PM10) en la zona este 2, un sector industrial ubicado en los distritos san juan de Lurigancho y Lurigancho-Chosica, Perú. Para tal fin, se propone el uso de indicadores duales: ecológicos y sociales. De acuerdo a los indicadores ecológicos explorados, la concentración media de PM10 en el aire exterior (CME) superó el límite de 100 µg/m3 establecido por MINAM. Aunque la mediana de CME (93,7µg/m3; IC 95%=89,07-98,33) estuvo por debajo de este límite, el cuartil superior lo superó, entendido por elevaciones puntuales de hasta 131 µg/m3 (Figura 2), potencialmente dañinos para la salud humana. El coeficiente de correlación de Spearman de 0,921, obtenido del análisis bivariado entre los valores de concentración media diaria de PM10 exterior e interior, previo a la instalación de filtros en los sistemas de ventilación, es sugerente del efecto que puede tener la inmisión de aire ambiental con material particulado como vector de la contaminación del aire interior. al considerar los valores de la concentración media diaria, obtenidos en los 15 días posteriores a la instalación de los filtros (CMIFI), se observa que la concentración media de PM10 en el interior disminuyó en relación a la quincena anterior. El coeficiente de correlación de Spearman de 0,869 entre los indicadores CMIFI y CME, permite proponer que, en esta segunda fase, la calidad del aire interior fue influenciada en menor proporción por la contaminación de material particulado del aire ambiental, es decir que se presentó menos inmisión de PM10, gracias al proceso de filtrado, lo que disminuye el riesgo para la salud de los trabajadores(AU)

Particulate matter (PM) is one of the most important pollutants present in the air, representing an environmental risk to health. Particles with a diameter of 10 microns or less (PM10), being inhalable, can penetrate and lodge deep in the lungs, contributing to the risk of developing cardiovascular and respiratory diseases, as well as lung cancer, mental illness, dermatitis, eye damage and even increased mortality rates. The objective was to determine the indoor air quality associated with the immission of particulate matter (PM10) in East Zone 2, an industrial sector located in the districts of San Juan de Lurigancho and Lurigancho-Chosica, Peru. To this end, the use of dual indicators is proposed: ecological and social. According to the ecological indicators explored, the average concentration of PM10 in outdoor air (CME) exceeded the limit of 100 µg/m3 established by MINAM. Although the CME median (93.7µg/m3; 95% CI=89.07-98.33) was below this limit, the upper quartile exceeded it, understood as point elevations of up to 131µg/m3 (Figure 2 ), potentially harmful to human health. Spearman's correlation coefficient of 0.921, obtained from the bivariate analysis between the daily average concentration values of outdoor and indoor PM10, prior to the installation of filters in the ventilation systems, is suggestive of the effect that the immission of ambient air can have with particulate matter as a vector of indoor air pollution. When considering the values of the average daily concentration, obtained in the 15 days after the installation of the filters (CMIFI), it is observed that the average concentration of PM10 in the interior decreased in relation to the previous fortnight. Spearman's correlation coefficient of 0.869 between the CMIFI and CME indicators allows us to propose that, in this second phase, indoor air quality was influenced to a lesser extent by particulate matter contamination in the ambient air, that is, there was less PM10 immission, thanks to the filtering process, which reduces the risk to the health of workers(AU)

Estructura organizacional del policlínico Julián Grimau para la respuesta médica ante emergencias químicas por amoníaco / Organizational structure of Julián Grimau polyclinic for medical response to chemical emergencies by ammonia

Introducción: El amoníaco constituye riesgo de emergencia química en el Policlínico Docente Julián Grimau del municipio Arroyo Naranjo, lo que hace necesario asumir una estructura organizacional que viabilice la respuesta médica frente a este tipo de eventos. Objetivo: Diseñar una propuesta de estructura organizacional del policlínico Julián Grimau para la respuesta médica ante emergencias químicas por amoníaco. Métodos: Se realizó una investigación en sistemas y servicios de salud, entre septiembre de 2017 y diciembre de 2018, en el Policlínico Docente Julián Grimau. Se analizaron documentos relacionados con las acciones médicas en las emergencias químicas en la atención primaria de salud. Se empleó el método sistémico estructural-funcional para diseñar la estructura organizacional, y el informante clave para su concreción. Resultados: Se propone una estructura organizacional de la respuesta médica a emergencias químicas por amoníaco en el Policlínico Docente Julián Grimau que se conformó por nueve áreas: punto de recepción (1), tratamiento especial (2), clasificación (3), tratamiento de urgencia al intoxicado grave (4), tratamiento de urgencia al intoxicado leve (5), aseguramiento al diagnóstico (6), aseguramiento médico material (7), el área de fallecidos (8) y asintomáticos (9). Conclusiones: La estructura organizacional de la respuesta médica a emergencias químicas por amoníaco en el Policlínico Docente Julián Grimau quedó conformada en áreas con sustento en los principios clínicos, evolutivos y de tratamiento del paciente intoxicado agudo, donde se aprovechan las potencialidades orgánicas y funcionales de la institución. Se caracteriza por ser sistémica, flexible, objetiva, participativa, oportuna, adecuada y selectiva(AU)

Introduction: At Julián Grimau Teaching Polyclinic in Arroyo Naranjo municipality, ammonia is a risk of chemical emergency. Hence, it is necessary for the medical response to these situations to implement an organizational structure. Objective: Design a proposal of organizational structure in Julián Grimau Polyclinic for the medical response to chemical emergency by ammonia. Methods: A research was carried out on health systems and services, from September 2017 to December 2018, in Julián Grimau Teaching Polyclinic. A documentary analysis related to medical actions in chemical emergencies was conducted in primary health care's level. In addition, the following methods were used: structural-functional system for the design of the organizational structure and the key informant for its concretion. Result: It is proposed an organizational structure of the medical response to chemical emergencies by ammonia in the Polyclinic, that was formed by nine areas: reception point (1), special treatment (2), classification (3), emergency treatment to severe poisoned patient (4), emergency treatment to slightly poisoned patient (5), logistics for the diagnosis (6), medical-material logistics (7), deceased´s area (8), and asymptomatic patients (9). Conclusions: The organizational structure of the medical response to chemical emergencies by ammonia in Julián Grimau Teaching Polyclinic was formed of areas secured by principles of clinical, evolutive and of acute poisoned patient´s treatment where the organic and functional potentials of the institution are seized. Hence, this proposal is flexible, objective, participatory, timely, adequate and selective(AU)

Aerobic stability of tifton 85 silage with and without pre-drying in the sun

The objective of this study was to evaluate pH, ammoniacal nitrogen, and aerobic stability of silage of Tifton 85 grass silage with two dry matter contents at different silos opening times. The experimental design was completely randomized, in a subdivided plots scheme, in which the silages constituted the plots and aerobic exposure times the subplots, with four replications. To verify the aerobic stability of the silages, the temperature and pH were analyzed at seven hours after the silos were opened (1, 24, 48, 72, 96, 120, and 144 hours). The pH reached adequate levels for conservation only after 90 days of fermentation for the silages with and without pre-drying in the sun. Ammoniacal nitrogen remained below the recommended limits in both silages. As for the silage temperature, no loss of aerobic stability was observed. However, the observed pH revealed a break instability after 72 hours when the silos were opened at 28 days, with no changes for the remaining silage periods. It is possible to obtain suitable silages from Tifton 85 with or without pre-warming in the sun, however, a minimum fermentation period of 90 days should be adopted. The studied silages presented high aerobic stability, but when kept silage for only 28 days, they should be consumed by the animals within 48 hours after the supply.

Effect of Fluoxetine Hydrochloride on Routine Metabolism of Lambari (Deuterodon iguape, Eigenmann, 1907) and Phantom Shrimp (Palaemon pandaliformis, Stimpson, 1871)

HIGHLIGHTS Fluoxetine increases the metabolic rate and excretion of ammonia in both species. O:N ratio in fish showed higher values in the highest concentrations of fluoxetine. The LC50 - 96 hour values of Palaemon pandaliformis represented greater toxicity. Both species are a good biological model for fluoxetine exposure studies.

Abstract Fluoxetine is an emerging pollutant that acts as a selective serotonin reuptake inhibitor (SSRI) and being a hydrolytic molecule that is photolytically stable and accumulaties in biological tissues, its disposal in the aquatic environment can interfere with the physiology of fish and shrimp. Thus, the objective of this study was to analyze the effects of fluoxetine on routine metabolism (metabolic rate, specific ammonia excretion and O:N ratio) of Deuterodon iguape and Palaemon pandaliformis. For this, five groups of each species, were exposed to different concentrations of fluoxetine for 24 hours (D. iguape) and 2 hours (P. pandaliformis). The results demonstrated that in D. iguape exposure to fluoxetine significantly increased both the metabolic rate by 75%, 85%, 55% and 50% for concentrations of 0.05; 0.1; 0.5 and 1.0 mgL-1, respectively, and the specific ammonia excretion by 40%, 48% and 20% for concentrations of 0.05; 0.1 and 0.5 mgL-1, respectively, when compared with their control. The O:N ratio was statistically greater in concentrations of 0.5 and 1.0 mgL-1. Concerning P. pandaliformis, exposure to fluoxetine increased metabolic rate at concentrations 30.0 and 60.0 µgL-1, and also increased specific ammonia excretion at concentrations 10.0, 30.0 and 60.0 µgL-1, when compared with the control group. It was concluded that exposure to fluoxetine increases the routine metabolism of both species and that at the concentration 1.0 mgL-1, Deuterodon iguape required different energy substrates.

Aquaponic System with White Shrimp Litopenaeus vannamei Rearing and Production of the Plants Batis maritima, Sarcocornia neei and Sporobolus virginicus

Abstract Aquaponics is a system that integrates aquaculture with plant production in which two species are benefited, and there is water saving. In this study was carried out with an aquaponic system to verify the interaction between the growth of the halophytes Batis maritime, Sarcocornia neei, and Sporobolus virginicus associated with white shrimp Litopenaeus vannamei rearing. We also investigated if there were different responses of physicochemical variables of the water in the experimental shrimp culture ponds integrated into the growth of plants and control ponds, without plants, throughout a 56-day period. The treatment experiment and control presented a statistically significant difference in total dissolved solids, salinity, total suspended solids, ammonia, orthophosphate, and nitrite. In the experimental treatment, with the presence of plants and recirculating water, a reduction of total suspended solids, ammonia and orthophosphate was observed. The rate of shrimp production was not significantly different between treatments, and the performance was similar to that of other studies. The biomass gain of the halophyte B. maritima was 876.6 grams in 0.5 m² and of S. neei was 48.8 grams in 0.16 m². All plants of the species S. virginicus died during the experiment.

Volatilization of ammonia in systems of treatment of swine manure with aquatic macrophytes / Volatilização de amônia em sistemas de tratamento de dejetos de suínos com macrófitas aquáticas

Abstract The usage of aquatic plants represents an alternative in the treatment of residues originating from swine. In these systems, one of the N removal methods is the ammonium (NH4 +) uptake and volatilization of ammonia (NH3). In this way, the objective of this work was to evaluate the volatilization rates of NH3 in waste treatment systems swine fluids (SSF) with aquatic macrophytes, as well as the concentration of NH 4+ present in the swine fluids. The experiment was carried out at Campus II/UNOESTE. The treatment systems were composed of 16 boxes of PVC and characterized as: T1 = Control sample 50% of SSF/50% of water; T2 = 50% SSF/50% water + Eichhornia crassipes (Mart.) Solms; T3 = 50% SSF/50% water + Pistia stratiotes L.; T4 = 50% SSF/50% water + Salvinia auriculata Aubl. The design was randomized blocks, with 4 treatments and 4 replicates. The hydrogen potential (pH) and the NH4 + content of the effluent were analyzed weekly, and the volatilization of NH 3 by means of collectors installed in each treatment unit. The presence of aquatic macrophytes promoted the reduction of NH4+ concentration and of the pH values ​​of swine fluids, and this resulted in the reduction of NH3 volatilization rates to the environment, with emphasis on the system with Eichhornia crassipes (Mart.) Solms, which presented the lowest rate of volatilization.

Resumo A utilização de plantas aquáticas representa uma alternativa no tratamento de resíduos oriundos da suinocultura. Nestes sistemas, uma das formas de remoção de nitrogênio (N) é a absorção de amônio (NH4+) pelas plantas, entretanto, também ocorre a volatilização de amônia (NH3). Dessa forma, o objetivo do trabalho foi avaliar as taxas de volatilização de NH3 em sistemas de tratamentos de dejetos líquidos de suínos (DLS) com macrófitas aquáticas, bem como a concentração de NH4+ presente nos dejetos. O experimento foi realizado em área de ambiente aberto no Campus II/UNOESTE. Os sistemas de tratamento foram constituídos de 16 caixas de PVC e caracterizados como: T1 = Testemunha 50% de DLS/50% de água; T2 = 50% de DLS/50% de água + Eichhornia crassipes (Mart.) Solms; T3 = 50% de DLS/50% de água + Pistia stratiotes L.; T4 = 50% de DLS/50% de água + Salvinia auriculata Aubl. O delineamento adotado foi em blocos casualizados, com 4 tratamentos e 4 repetições. Foram analisados o potencial hidrogeniônico (pH) e o teor de NH4 + do efluente semanalmente, e a volatilização de NH3 por meio de coletores instalados em cada unidade de tratamento. A presença das macrófitas aquáticas proporcionou a redução da concentração de NH4+ e dos valores de pH dos dejetos líquidos de suínos, e isto resultou na redução das taxas de volatilização de NH 3 ao meio ambiente, com destaque ao sistema com Eichhornia crassipes (Mart.) Solms, que apresentou a menor taxa de volatilização.

Ammonia volatilization in response to coated and conventional urea in maize crop field / Volatilização de amônia utilizando ureia convencional e revestida na cultura do milho

The properly measurement of gas emissions and nutrient availability to crops using technologies such as polymer-coated urea are required to monitored the possible nitrogen (N) fertilizer pollution in the environment. This study aimed to evaluate N loss through ammonia volatilization from polymer-coated and conventional urea in maize field trials under two different environments. The study was carried out in Chapadão do Sul and Selvíria State of Mato Grosso do Sul evaluating the first and second harvest of maize plants. Nitrogen fertilizers were applied as polymer-coated, conventional urea and control plots were used as reference to evaluate N loss through volatilization (3, 6, 9, 12, and 15 days after fertilizer application). The peak of ammonia volatilization was observed during the first three days after fertilizer application corresponding up to 44% of total N supplied. Polymer-coated urea had promising results showing less ammonia volatilization during the first crop. However, the same result was not observed for second crop.

A necessidade de mensurar adequadamente a emissão de gases e também o fornecimento de nutrientes às culturas por tecnologias como o revestimento da ureia com polímeros são necessários para monitar a possível poluição de fertilizantes nitrogenados no ambiente. Assim, o objetivo desse trabalho foi determinar as perdas de nitrogênio (N) por volatilização pela ureia convencional e ureia revestida compolímero, em duas épocas de cultivo do milho (Zea mays L.), em duas regiões do cerrado brasileiro. Os trabalhos foram desenvolvidos em Chapadão do Sul e Selvíria, Mato Grosso do Sul - Brasil, na cultura do milho "primeira safra" e "segunda safra", respectivamente. Os tratamentos foram constituídos pela ureia e ureia revestida por polímero aplicada em cobertura além de um tratamento controle (sem N) em função de épocas de monitoramento das perdas de N por volatilização (3, 6, 9, 12 e 15 dias após a adubação) com 5 repetições. Foi mensurado as perdas de N por volatilização nas respectivas épocas e o total acumulado no período. O pico de volatilização ocorreu durante os três primeiros dias, atingindo patamares de até 44% do total de N fornecido. O revestimento da ureia com polímeros apresentou resultados promissores, diminuindo as perdas de N-NH3 por volatilização no milho "primeira safra". Todavia, os resultados obtidos no milho "segunda safra" não permitem generalizar tais benefícios.

Ammonia determines transcriptional profile of microorganisms in anaerobic digestion

ABSTRACT Anaerobic digestion is important for the management of livestock manure with high ammonia level. Although ammonia effects on anaerobic digestion have been comprehensively studied, the molecular mechanism underlying ammonia inhibition still remains elusive. In this study, based on metatranscriptomic analysis, the transcriptional profile of microbial community in anaerobic digestion under low (1500 mg L-1) and high NH4 + (5000 mg L-1) concentrations, respectively, were revealed. The results showed that high NH4 + concentrations significantly inhibited methane production but facilitated the accumulations of volatile fatty acids. The expression of methanogenic pathway was significantly inhibited by high NH4 + concentration but most of the other pathways were not significantly affected. Furthermore, the expressions of methanogenic genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase were significantly inhibited by high NH4 + concentration. The inhibition of the co-expressions of the genes which encode acetyl-CoA decarbonylase was observed. Some genes involved in the pathways of aminoacyl-tRNA biosynthesis and ribosome were highly expressed under high NH4 + concentration. Consequently, the ammonia inhibition on anaerobic digestion mainly focused on methanogenic process by suppressing the expressions of genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase. This study improved the accuracy and depth of understanding ammonia inhibition on anaerobic digestion.

Validación de una prueba de amonio en aliento para el diagnóstico de la infección por Helicobacter pylori en pacientes del Hospital Cayetano Heredia / Validation of an ammonia breath test for the diagnosis of Helicobacter pylori infection in patients with dyspepsia at Hospital Cayetano Heredia

Objetivo: Determinar la validez diagnóstica de una prueba de amonio en aire espirado para la infección por Helicobacter pylori en pacientes a los que se le realiza una endoscopía digestiva alta en el Hospital Cayetano Heredia. Material y métodos: De abril a diciembre del 2014 se evaluó a 155 pacientes con una prueba de amonio en aliento y la evaluación histopatológica de las biopsias de estómago (considerada como el patrón de oro) tomadas durante la endoscopía. Los datos fueron analizados en Microsoft Excel y STATA 14 para construir una curva ROC. Resultados: Los pacientes fueron predominantemente mujeres (71%), con una edad media de 53 años (18-84) y una prevalencia de Helicobacter pylori de 51,6%. Al comparar la prueba de amonio en aire espirado con la prueba histológica se obtiene una sensibilidad de 70%, especificidad de 36%, valor predictivo positivo de 53,8%, valor predictivo negativo de 36%, índice de probabilidad positivo de 1,15 e índice de probabilidad negativo de 0,75. De acuerdo a la curva ROC, no se encontró un punto de corte óptimo con adecuados valores de sensibilidad y especificidad y el área bajo la curva es de 0,5517. Conclusiones: Esta prueba de amonio en aliento (aire espirado) no presenta poder diagnóstico y no se recomienda como una herramienta para el diagnóstico de la infección por Helicobacter pylori.

Objetive: To determine the diagnostic validity of an ammonia breath test for Helicobacter pylori infection in patients who undergo an upper gastrointestinal endoscopy at Hospital Cayetano Heredia. Material and methods: From April to December 2014, 155 patients were evaluated with the ammonia breath test and compared with a histological evaluation of the gastric biopsies as the gold standard. Data were evaluated using Microsoft Excel and STATA 14 to build a ROC curve. Results: The patients were predominantly female (71%), with a median age of 53 years (18-84) and a Helicobacter pylori prevalence of 51.6%. The ammonia breath test, when compared to the gastric biopsy has a 70% sensitivity, 36% specificity, 53.8% positive predictive value, 36% negative predictive value, 1.15 positive likelihood ratio and 0.75 negative likelihood ratio. According to the ROC curve, there is not an optimal cut off value and the area under the curve was 0.5517. Conclusions: The ammonia breath test evaluated on this study does not have diagnostic accuracy and is not recommended as a diagnostic tool for Helicobacter pylori infection.

The use of Prevotella bryantii 3C5 for modulation of the ruminal environment in an ovine model

Abstract In the Southern Hemisphere, ruminants are mostly raised in grazing systems where animals consume forage and are supplemented with low amounts of concentrates. Concentrates are usually given separately and are rapidly ingested. This practice leads to changing rumen environment conditions during the day, may alter the rumen microbial metabolism and could affect host performance. The native ruminal Prevotella bryantii strain 3C5 was administered every 48 h to wethers under experimental conditions simulating Southern-Hemisphere feeding to evaluate its potential as a rumen fermentation modulator. The inoculum potential was assessed on day 17. The ammonia nitrogen (NH3-N), volatile fatty acids and ruminal pH were monitored on a 24-h basis 19 days after the beginning of the experiment, and the microbial community structure was assessed by pyrosequencing. The administration of P. bryantii modified the fermentation products and daily pH values compared to the control. The NH3-N concentration in the rumen of treated animals was significantly higher than that of the untreated animals. Modification of the ruminal environment and fermentation pathways was achieved without altering the general structure of the microbial community or the potential methane production. P. bryantii 3C5 could be considered in potential probiotic formulations for ruminants in semi-intensive systems.

Chronic effects of nitrogenous compounds on survival and growth of juvenile pink shrimp / Efeito crônico de compostos nitrogenados sobre a sobrevivência e crescimento de juvenis de camarão rosa

Abstract In response to growing worldwide market demand, intensive shrimp farming, based on high feed, has developed over the past decade. The nitrogenous compounds mainly generated by animal excretion can cause deterioration of water quality and produce chronic or even acute toxicity to aquatic animals. As prevention, theoretical safety levels have been estimated from acute toxicity tests and they are traditionally used to prevent toxic effects on biota. However, are those concentrations of nitrogenous compounds really safe to Farfantepenaeus paulensis? The current study aimed to investigate the lethal and sublethal effects of ammonia, nitrite and nitrate to juvenile F. paulensis based on safety levels. Each experiment was performed independently in 100 L tanks for 30 days. The survival rates and wet weight of all shrimps were recorded every 10 days. The concentrations tested for ammonia, nitrite and nitrate were respectively: treatment "T1/4", a quarter of the safety level (0.91 mg/L TA-N, 2.55 mg/L NO2--N and 80.7 mg/L NO3--N); treatment "TSL", the safety level (3.65 mg/L TA-N, 10.2 mg/L NO2--N and 323 mg/L NO3--N); and treatment "T2X", twice the safety level (7.30 mg/L TA-N, 20.4 mg/L NO2--N and 646 mg/L NO3--N). For F. paulensis cultivation, the real safety level for nitrite was estimated to be 2.55 mg/L NO2--N. For ammonia and nitrate, the recommended concentrations were <0.91 mg/L TA-N corresponding to 0.045 mg/L NH3-N and <80.7 mg/L NO3--N, respectively.

Resumo Em resposta à crescente demanda do mercado mundial, a carcinicultura intensiva tem se desenvolvido ao longo da última década. Os compostos nitrogenados gerados principalmente pela excreção dos animais podem causar a deterioração da qualidade da água e produzir toxicidade crônica ou mesmo aguda para os animais cultivados. Como prevenção, os níveis de segurança teóricos são estimados a partir de testes de toxicidade aguda e são tradicionalmente usados para evitar efeitos tóxicos sobre a biota. No entanto, as estimativas das concentrações dos compostos nitrogenados são realmente seguras para Farfantepenaeus paulensis? O presente estudo teve como objetivo investigar os efeitos letais e subletais da amônia, nitrito e nitrato em juvenis de camarão marinho F. paulensis com base em níveis de segurança. Cada experimento foi realizado de forma independente em tanques com capacidade de 100 L durante 30 dias. As taxas de sobrevivência e peso úmido de todos os camarões foram registrados a cada 10 dias. As concentrações testadas para amônia, nitrito e nitrato foram respectivamente: "T1/4", um quarto do nível de segurança (0,91 mg/L N-AT, 2,55 mg/L de N-NO2- e 80,7 mg/L N-NO3-); "TSL", nível de segurança (3,65 mg/L N-AT, 10,2 mg/L de N-NO2- e 323 mg/L N-NO3-); e "T2X", duas vezes o nível de segurança (7,30 mg/L N-AT, 20,4 mg/L de N-NO2- e 646 mg/L de N-NO3-). Para a criação de F. paulensis, o nível de segurança real para nitrito foi estimado em 2,55 mg/L N-NO2-. Para amônia e nitrato, concentrações recomendadas foram: <0,91 mg/L N-AT correspondente a 0,045 mg/L N-NH3 e <80,7 mg/L N-NO3-, respectivamente.

Immobilization of ammonia-oxidizing bacteria by polyvinyl alcohol and sodium alginate

Abstract Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30 °C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability.

Biogenic amines and mycotoxins concentrations in baled silage from organic and conventional farms / Concentrações de aminas biogênicas e micotoxinas em silagem embalada de fazendas orgânicas e convencionais

The aim of the current study was to investigate biogenic amines and mycotoxins concentrations in baled silage (mainly Poaceae family grasses) prepared in organic and conventional farms and to relate these parameters to fermentative parameters. The mean dry matter (DM) content was 364.10±93.31 and 424.70±95.93g/kg in the silage from organic and conventional farms respectively. The silage samples from organic farms had 17.00% higher (P≤ 0.05) tyramine (TY) than the silage from conventional farms. Conventional farm samples were characterized by 46.00% higher histamine (HIS) (P≤ 0.05), 9.80% higher putrescine (PUT) (P≤ 0.05), 17.30% higher cadaverine (CAD) (P≤ 0.05). Aflatoxins (AFL) (total) and zearalenone (ZEN), T-2/HT-2 concentrations were higher respectively 16.00% (P≤ 0.05) and 13.40% (P≤ 0.05), 1.80% (P≤ 0.05) in the silage prepared in organic farms. Deoxynivalenol (DON) concentration was higher 42.40% (P≤ 0.05) in silage from conventional farms. Volatile fatty acids (VFA), lactic acid, ethanol, pH and ammonia nitrogen showed that the silage samples from organic and conventional farms were of good quality. Our study suggests differences in biogenic amine formation or mycotoxins content in silage from organic and conventional farming, but, overall, the measured values are too low to be relevant for animal health. Furthermore, these differences might as well be due to the difference in dry matter content and plant maturity between the organic and conventional silage samples.(AU)

O objetivo do presente estudo foi investigar concentrações de aminas biogênicas micotoxinas em silagem embalada (principalmente gramíneas da família Poaceae) preparada em fazendas orgânicas e convencionais e relacionar esses parâmetros a parâmetros fermentativos. A massa seca média (MS) foi 364,10±93,31 e 424,70±95,93g/kg na silagem de fazendas orgânicas e convencionais, respectivamente. As amostras de silagem de fazendas orgânicas tinham 17% a mais de tyramina (TY) (p≤ 0,05) que as de fazendas convencionais. As amostras de fazendas convencionais foram caracterizadas por histamina (HIS) 46,00% mais alta (P≤ 0,05), 9,80% putrecina (PUT) mais alta (P≤ 0,05), 17,30% de cadaverina (CAD) mais alta (P≤ 0,05). Aflatoxnas (AFL) (total) e zearalenone (ZEN), T-2/HT-2 tinham concentrações mais altas em respectivamente 16,00% (P≤ 0,05) e 13,40% (P≤ 0,05), 1,80% (P≤ 0,05) na silagem preparada em fazendas orgânicas. Deoxinivalenol (DON) tinha concentração mais alta 42,40% (P≤ 0,05) na silagem de fazendas convencionais. Ácidos graxos voláteis (AGV), ácido lático, etanol, pH e nitrogênio de amônia mostraram que as amostras de silagem de fazendas orgânicas e convencionais tinham boa qualidade. Nosso estudo sugere diferenças na formação biogênica de amônia ou micotoxinas em silagem de fazendas orgânicas ou convencionais mas, em geral, os valores medidos foram muito baixos para serem relevantes à saúde animal. Ademais, essas diferenças podem ser devido à diferença na matéria sólida e maturidade da planta entre as amostras de silagem orgânica e convencional.(AU)

Bacterial selection for biological control of plant disease: criterion determination and validation

Abstract This study aimed to evaluate the biocontrol potential of bacteria isolated from different plant species and soils. The production of compounds related to phytopathogen biocontrol and/or promotion of plant growth in bacterial isolates was evaluated by measuring the production of antimicrobial compounds (ammonia and antibiosis) and hydrolytic enzymes (amylases, lipases, proteases, and chitinases) and phosphate solubilization. Of the 1219 bacterial isolates, 92% produced one or more of the eight compounds evaluated, but only 1% of the isolates produced all the compounds. Proteolytic activity was most frequently observed among the bacterial isolates. Among the compounds which often determine the success of biocontrol, 43% produced compounds which inhibit mycelial growth of Monilinia fructicola, but only 11% hydrolyzed chitin. Bacteria from different plant species (rhizosphere or phylloplane) exhibited differences in the ability to produce the compounds evaluated. Most bacterial isolates with biocontrol potential were isolated from rhizospheric soil. The most efficient bacteria (producing at least five compounds related to phytopathogen biocontrol and/or plant growth), 86 in total, were evaluated for their biocontrol potential by observing their ability to kill juvenile Mesocriconema xenoplax. Thus, we clearly observed that bacteria that produced more compounds related to phytopathogen biocontrol and/or plant growth had a higher efficacy for nematode biocontrol, which validated the selection strategy used.

Zeólitas naturais na dieta de frangos de corte / Natural zeolites in broiler diet

O objetivo deste trabalho foi avaliar o efeito da inclusão de 0,5% da zeólita natural clinoptilolita na dieta de frangos de corte sobre o consumo de água, ração e características das excretas. Foi conduzido um ensaio em gaiolas metabólicas, com frangos de corte de linhagem comercial, no período de 14 a 23 dias de idade. O experimento foi constituído de dois grupos de aves, sendo que um recebeu dieta sem inclusão de zeólitas (controle) e outro dieta com inclusão de 0,5% de zeólita (clinoptilolita) em rações isonutritivas, em um delineamento inteiramente ao acaso, com 10 repetições de 10 aves. Avaliou-se o consumo de água e de ração, nas excretas, pH, teor de nitrogênio total e umidade. A inclusão de 0,5% de zeólitas naturais na dieta não alterou (P>0,05) o consumo de água e de ração e o teor de nitrogênio das excretas, entretanto, reduziu (P<0,05) o pH e a umidade das excretas. Conclui-se que a inclusão de 0,5% de zeólitas naturais na dieta de frangos de corte reduz o pH e a umidade das excretas e pode ser utilizada como aditivo alimentar sem prejudicar o consumo de água e de ração.(AU)

The aim of this study was to evaluate the addition of 0.5% natural zeolites (clinoptilolite) to the diet of broilers and their effect on water and feed intake and excreta characteristics. The test was carried out in metabolic cages, with commercial line broilers, in the period from 14 to 23 days old. The experiment was conducted with two groups of broilers: one group received diet without zeolite inclusion (control) and the other received a diet with 0.5% inclusion of zeolite (clinoptilolite) in balanced diets, in a completely randomized design, with 10 replicates of 10 broilers. Water and feed intake, pH, total nitrogen, and moisture of excreta were evaluated. The inclusion of 0.5% of natural zeolites in the diet did not change (P>0.05) the water and feed intake and total nitrogen of excreta, nevertheless, it decreased (P<0.05) the pH and moisture of excreta. We conclude that the addition of 0.5% natural zeolites to the diet of broilers decreases pH and moisture of excreta and can be used as feed additive without compromising water and feed intake.(AU)

Association between MFN2 gene polymorphisms and the risk and prognosis of acute liver failure: a case-control study in a Chinese population

This study aimed to determine the role of mitofusin 2 (MFN2) gene polymorphisms in the risk and prognosis of acute liver failure (ALF). A total of 298 blood samples were collected from 138 ALF patients (case group) and 160 healthy participants (control group). Coagulation function, glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), total bilirubin (TB), blood ammonia and lactic acid (LA) were measured. The predictive evaluation of MFN2 gene polymorphisms in the risk and prognosis of ALF patients was estimated using Kaplan-Meier survival analysis, haplotype analysis, binary logistic regression analysis and Cox regression analysis. Higher levels of GPT, GOT, TB, blood ammonia and LA were observed in ALF patients with the GG genotype of rs873457 or the TT genotype of rs4846085 than in those with the CC genotype of these two SNPs. The GTACAGC and GTGTGGC haplotypes were a protective factor and a risk factor for ALF, respectively. Blood ammonia and LA levels were independent risk factors and the CC genotype of rs873457 and the CC genotype of rs4846085 were protective factors for ALF. ALF patients with the GG genotype of rs873457 or the TT genotype of rs4846085 had a lower survival rate than those with other genotypes of these two SNPs. The rs4846085 and rs873457 polymorphisms were both independent factors affecting the prognosis of ALF patients. MFN2 gene polymorphisms (rs873457, rs2336384, rs1474868, rs4846085 and rs2236055) may be associated with ALF and the rs873457 and rs4846085 polymorphisms are correlated with the risk and prognosis of ALF.