Reactive Arthritis as a Consequence of Infection by Clostridium difficile in a Pediatric Patient.

Reactive arthritis (RA) is the development of a sterile inflammatory arthritis usually associated with a previously known infection, most commonly from the gastrointestinal or urogenital tract. The diagnosis is clinical, based on the presence of acute oligoarticular arthritis of larger joints developing within two to four weeks of the infection. However, in some cases where the infection is not clear, the diagnosis is a challenge, like in the case presented here. We must always rule out past infections as a cause of arthritis by directly asking about the presence of symptomatology associated with it, presented in the past few weeks. It's important to emphasize that human leukocyte antigen B27 (HLA-B27) should not be used as a diagnostic tool, and it always needs to be correlated with the clinical features. There is no confirmed evidence in the literature that is in favor of prescribing antibiotic therapy during an acute presentation of RA as it usually presents after the infection is cured.

Integration of mesophilic biogas plant in the animal slaughter process under real limitations: Techno-economic evaluation of a colombian bovine slaughterhouse.

Anaerobic digestion (AD) has been a widely tested alternative for the management and valorization of wastewater from the animal slaughter process. However, the integration of AD in slaughterhouses depends on technical and economic aspects. In Colombian slaughterhouses AD integration is limited by the availability of land. In the present study, a techno-economic evaluation of the AD of offal wastewater (OWW) stream in a laboratory scale mesophilic tubular digester was carried out. The digester was operated at organic loading rates (OLR) of 0.28, 0.50, 1.0, 1.5 and 2.0 kg VS/m3 d. Boilers and a CHP (combined heat and power) system were considered for energy integration of biogas. For the economic study, the cost structure of a Colombian slaughterhouse was considered. The AD of OWW at 2.0 kg VS/m3 d OLR was unstable with risk of inhibition. Increasing the OLR from 0.28 to 1.5 kg VS/m3 d caused a reduction in the specific biogas production (SBP) from 0.474 to 0.069 m3/kg VS However, the biogas production rate (BPR) remained constant at around 0.105 m3/m3dig d for OLRs > 0.28 kg VSm3 d. Therefore, OWW anaerobic digestion in low-cost mesophilic biogas plants is technically feasible with OLRs between 0.28 and 1.5 kg VS/m3 d. The implementation of boilers is economically favorable for OLR ≥ 1.0 kg VS/m3 d. Nevertheless, feasibility is very sensitive to variations in the cost structure. The implementation of CHP was feasible in the range of OLRs evaluated and its viability is not affected by changes in assumed costs.

Post-treatment and agricultural reuse of digestate from low-tech digesters: A comparative life cycle assessment.

The objective of this study was to analyse the environmental impacts of the post-treatment and agricultural reuse of digestate from a low-tech digester implemented in a small-scale farm in Colombia using the Life Cycle Assessment methodology. The scenarios considered were: 1) digestate post-treatment with a sand filter and its reuse in agriculture; 2) digestate post-treatment with a vermifilter and the production of compost, and 3) untreated digestate directly applied on the agricultural land (current scenario). Moreover, an economic analysis was also addressed. Results showed that the vermifilter was the most environmentally friendly scenario. It considerably reduced (by up to 9 times) the environmental impacts compared to the other scenarios. From an economic point of view, the implementation of the vermifilter generated an increase in farmers' income (up to 70 $ year-1) since it avoids buying synthetic fertilizer. Finally, the implementation of a vermifilter for the post-treatment and agricultural reuse of digestate from low-tech digesters showed to have both environmental and economic benefits. This technology can help to promote the circular bioeconomy in small-scale farms, reducing poverty and improving the standard of living in rural areas.

Low-cost anaerobic digester to promote the circular bioeconomy in the non-centrifugal cane sugar sector: A life cycle assessment.

This study aimed to assess the potential environmental benefits of implementing low-cost digesters to valorize agro-industrial waste in the non-centrifugal cane sugar (NCS) sector. Two scenarios were considered: i) the current scenario in which organic waste and wastewater were burned outdoor and discharged into a water body, respectively; ii) the anaerobic digestion (AD) scenario, in which low-cost biodigesters were used for organic waste and wastewater treatment on-site. Results showed that low-cost digesters were a sustainable alternative to mitigate environmental impacts, especially those associated with water source pollution. Indeed, in the AD scenario, the environmental impact categories of Freshwater Eutrophication and Marine Eutrophication showed a decrease of 87.6% and 99.4%, respectively, compared to the current scenario. Thus, by treating organic waste and wastewater on-site while producing bioproducts (i.e. biofuel and biofertilizer), low-cost digesters could contribute to boosting the circular bioeconomy in the NCS production sector.

Benefits and risks of agricultural reuse of digestates from plastic tubular digesters in Colombia.

The aim of this study is to characterize the digestates from three plastic tubular digesters implemented in Colombia fed with: i) cattle manure; ii) cattle manure mixed with cheese whey; iii) pig manure. All the digesters worked under psychrophilic conditions. Physico-chemical characteristics, heavy metals, pathogens, and agronomic quality were investigated. All the digestates were characterized by physico-chemical characteristics and nutrients concentration suitable for their reuse as biofertilizer. However, these digestates may only partially replace a mineral fertilizer due to the high nutrients dilution. Heavy metals were under the detection limit of the analytical method (Pb, Hg, Ni, Mo, Cd, Chromium VI) or present at low concentration (Cu, Zn, As, Se) in all the digestates. Biodegradable organic matter and pathogens (coliform, helminths and Salmonella spp.) analysis proved that all the digestates should be post-treated before soil application in order to prevent environmental and health risks, and also to reduce residual phytotoxicity effects. The digestate from pig manure had a higher nutrient percentage (0.2, 0.6 and 0.05 % w/w of total N, P2O5 and K2O, respectively), but also higher residual phytotoxicity than the other digestates. Co-digestion seemed not to significantly improve the digestate fertilizing potential. Finally, further studies should address how to improve fertilizing potential of digestates from plastic tubular digesters, avoiding environmental and health risks.

Evaluating environmental benefits of low-cost biogas digesters in small-scale farms in Colombia: A life cycle assessment.

The aim of this study was to assess the environmental benefits of implementing low-cost digesters in small-scale farms in Colombia by using the LCA methodology. Four scenarios were taken into account considering two small-scale farms located in different areas: two (previous) scenarios where manure was stored in a manure pit and liquefied petroleum gas (LPG) was used for cooking; and two (current) scenarios where manure is treated in low-cost digesters, the digestate replaces the synthetic fertiliser and the biogas is used for cooking replacing the LPG. Results showed that digesters implementation considerably reduced (by up to 80%) potential environmental impacts associated with manure handling, fuel and fertiliser use in the small-scale Colombian farms. This was mainly due to the reduction of LPG and synthetic fertiliser use which were replaced by biogas and digestate. An economic assessment showed that low-cost digesters reduced expenses associated with cooking fuel and fertiliser purchase by 80%.

Spatial decision support system to evaluate crop residue energy potential by anaerobic digestion.

Implementing anaerobic digestion (AD) in energy production from crop residues requires development of decision tools to assess its feasibility and sustainability. A spatial decision support system (SDSS) was constructed to assist decision makers to select appropriate feedstock according to biomethanation potential, identify the most suitable location for biogas facilities, determine optimum plant capacity and supply chain, and evaluate associated risks and costs. SDSS involves a spatially explicit analysis, fuzzy multi-criteria analysis, and statistical and optimization models. The tool was validated on seven crop residues located in Santander, Colombia. For example, fique bagasse generates about 0.21millionm(3)CH4year(-1) (0.329m(3)CH4kg(-1) volatile solids) with a minimum profitable plant of about 2000tonyear(-1) and an internal rate of return of 10.5%. SDSS can be applied to evaluate other biomass resources, availability periods, and co-digestion potential.

Influence of nutritional and physicochemical variables on PHB production from raw glycerol obtained from a Colombian biodiesel plant by a wild-type Bacillus megaterium strain.

Biodegradable polymers are currently viable alternatives to traditional synthetic polymers. For instance, polyhydroxybutyrate (PHB) is intracellularly produced and accumulated by Bacillus species, among others. This study reports several wild-type Bacillus strains with the ability to accumulate PHB using raw glycerol from biodiesel production as the sole carbon source. Out of 15 strains from different sources, B. megaterium B2 was selected as the most promising strain for further statistical optimization of the medium composition. Plackett-Burman and central composite designs were used to establish key variables and optimal culture conditions for PHB production using both 250-mL shake flasks and a 7.5-L bioreactor. Temperature and concentrations of glycerol and Na2HPO4 are the experimental variables with the most significant influence on PHB production by B2. After 14 hours of fermentation in shake flasks with optimized medium, B2 produced 0.43 g/L of PHB with a 34% accumulation in the cells. In contrast, under the same conditions, a maximum PHB concentration of 1.20 g/L in the bioreactor was reached at 11 hours. These values correspond to a 48% and 314% increase in PHB production compared to the initial culture conditions. These results suggest the potential of B2 as a PHB producer using raw glycerol, which is an inexpensive, abundant and readily available carbon source.

Enhancement of starting up anaerobic digestion of lignocellulosic substrate: fique's bagasse as an example.

In Colombia there are 20,000 ha of fique fields (Furcraea sp., family Agavaceae), that produce around 93,400 tons of fique's bagasse per year. These residuals are disposed into rivers and soil causing pollution. According to physicochemical characteristics, the lignocellulosic residues from fique crops (fique's bagasse) are appropriate carbon source to biogas production. Anaerobic digestion from fique's Bagasse (FB) requires a specialized microbial consortium capable of degrading its high lignocellulosic concentration. In this study, the capacities of seven microbial consortia for biomethane potential (BMP) from FB were evaluated. Inoculum of ruminal liquid achieved high hydrolytic activity (0.068 g COD/g VSS day), whereas pig waste sludge inoculum showed high methanogenic activity (0.146 g COD/g VSS day). Mixtures of these two inoculums (RL+PWS) showed the best yields for biomethane potential (0.3 m(3) CH4/Kg VS ad).

Co-digestión anaerobia de vinaza y gallinaza de jaula: alternativa para el manejo de residuos agrícolas colombianos / Anaerobic co-digestion of vinasse and chicken manure: alternative for Colombian agrowaste management

La digestión anaerobia es una tecnología atractiva para el manejo de residuos al producir energía en forma de biogás y estabilizar la materia orgánica. En este estudio, se evaluó el proceso de co-digestión de vinaza y gallinaza de jaula como una alternativa de manejo y estabilización de residuos generados por la agroindustria colombiana. Se llevaron a cabo, ensayos de biometanización en relaciones de mezcla vinaza y gallinaza de 1:0, 3:1, 1:3 y 0:1 en base a VS. La relación de 3:1 de vinaza y gallinaza permitió aumentar la producción específica de metano en un 55% respecto a la producción específica ponderada de 0.65 m³ CH4/kg VS. Las mezclas entre los sustratos presentaron un efecto sinérgico positivo. La gallinaza de jaula mejoró la capacidad de amortiguación de la mezcla, disminuyendo el riesgo de acidificación por cambio drástico en el pH durante la digestión de la vinaza. Por otra parte, la vinaza permitió diluir la concentración total de nitrógeno amoniacal evitando la inhibición de amoniaco. Dado el aumento de la producción de metano, el co-tratamiento de vinaza y gallinaza mejora la recuperación de energía y la viabilidad económica de la instalación de la planta de biogás como parte de la cadena de producción de etanol.

Anaerobic digestion is an attractive technology for waste management meanwhile energy is recovering. This study evaluated the feasibility of codigesting vinasse and chicken manure (CM) as management alternative for Colombian agro industries. Biochemical methane potential was tested for different vinasse to CM ratios of 1:0, 3:1, 1:3 and 0:1 on VS basis. Vinasse and CM ratio of 3:1 increased the specific methane production up to 55% regard to the weighted specific methane production of 0.65 m³CH4/kg VS. Mixtures between the substrates had a positive synergistic effect. CM improved buffer capacity diminishing the risk on acidification by drastic pH shift during vinasse digestion. Furthermore, vinasse allowed dilution of total ammonia nitrogen concentration avoiding ammonia inhibition. Since a higher methane production, vinasse and CM co-treatment improves the energy-recovery and economic feasibility of installing biogas plant as part of the ethanol production chain.

Efecto de la carga orgánica de la gallinaza de jaula en el potencial de biometanización / Effect of chicken manure organic load on biomethane potential

El propósito de este estudio fue evaluar el efecto de la carga orgánica expresada en función de la relación inóculo/sustrato (RIS) sobre el potencial de biometanización de la gallinaza de jaula usando como inóculo lodo estiércol bovino. Se llevaron a cabo ensayos de biodegradación anaerobia a temperatura mesofílica de 39 °C. Para cada una de las cargas orgánicas evaluadas (16.6, 11.0, 8.3, 6.6 y 5.5 g SV/L) se cuantificaron las variables: ácidos grasos volátiles totales, alcalinidad, concentración amonio y volumen acumulado de metano. El mayor potencial de biometanización (0.58 m³ CH4/kg SV) se alcanzó cuando la biodegradación anaerobia se llevó a cabo con una RIS de 1.0. Los resultados obtenidos demuestran que la gallinaza es un sustrato potencial para ser degradado por digestión anaerobia y el rendimiento del proceso es directamente proporcional a la concentración de sustrato. Este estudio también confirma que la RIS permite diluir la concentración de compuestos inhibitorios como el amonio en el caso de la gallinaza de jaula.

The aim of this study was to evaluate the effect of inoculum to substrate radio (ISR) on biomethane potential of chicken manure using cattle slurry as inoculum. Biomethane potential assays were carried out at 39 °C mesophilic temperature. Total fatty acids, total alkalinity, ammonium concentration and accumulative methane volume were measured to evaluate organic load (16.6, 11.0, 8.3, 6.6 y 5.5 g VS/L). The highest biomethane potential (0.58 m³ CH4/kg SV) was reached when anaerobic biodegradation was carried out to ISR of 1.0. The results demonstrated that chicken manure is a potential substrate to be degraded by anaerobic digestion and process performance is directly proportional to substrate concentration. This study also confirms that ISR allow dilution of inhibitory components as ammonium by the case of chicken manure.

Laparoscopia y su utilidad en el tratamiento del testículo impalpable / Usefulness of fluoroscopy in the treatment of impalppable testicle

Se desarrolló una técnica laparoscópica para el diagnóstico y el tratamiento de pacientes con testículo impalpable. A través de una pequeña incisión umbilical fue posible la exploración sistemática de la cavidad abdominopélvica después de inducir neumoperitoneo por medio de un insuflador automático de bióxido de carbono. Fue posible la identificación de los vasos gonadales y el conducto deferente al entrar en el conducto inguinal. Se corroboró el diagnóstico de anorquia al no encontrar estructuras gonadales o de los anexos. Se describe la orquiectomía laparoendoscópica. Se consideró que, entre los procedimientos seguros y eficaces, esta técnica es un recurso importante para la cirugía urológica