Codon-Optimized and de novo-Synthesized E-Selectin/AAV2 Dose-Response Study for Vascular Regeneration Gene Therapy.

OBJECTIVE: This study focuses on dose-response investigation using a codon-optimized and de novo-synthesized E-Selectin/AAV2 (E-Sel/AAV2) vector in preparation for Investigational New Drug (IND)-enabling of subsequent clinical studies. BACKGROUND: Gene therapy is a potential solution for patients suffering from chronic limb-threatening ischemia (CLTI). Understanding the dose for effective gene delivery is crucial for future IND-enabling studies. METHODS: Expression of the codon-optimized E-Selectin gene was assessed by flow cytometry following in vitro cell transfection assay and RT-qPCR for murine limbs injected in vivo with AAV-m-E-Selectin (E-Sel/AAV2). Dose-response studies involved three cohorts of FVB/NJ mice (n=6/group) with escalating log doses of E-Selectin/AAV2 injected intramuscularly (IM) in divided aliquots, ranging from 2×109 VG to 2×1011 VG, into ischemic limbs created by left femoral artery/vein ligation/excision and administration of nitric oxide synthase inhibitor, L-NAME. Limb perfusion, extent of gangrene free limb, functional limb recovery and therapeutic angiogenesis were assessed. RESULTS: Codon-optimized E-Sel/AAV2 gene therapy exhibits superior expression level than WT E-Sel/AAV2 gene therapy both in vitro and in vivo. Mice treated with a high dose (2×1011 VG) of E-Sel/AAV2 showed significantly improved perfusion indices, lower Faber's scores, increased running stamina and neovascularization compared with lower doses tested with control groups, indicating a distinct dose-dependent response. No toxicity was detected in any of the animal groups studied. CONCLUSION: E-Sel/AAV2 Vascular Regeneration Gene Therapy (VRGT) holds promise for enhancing the recovery of ischemic hindlimb perfusion and function, with the effective dose identified in this study as 2×1011 VG aliquots injected IM.

Nectar and floral morphology differ in evolutionary potential in novel pollination environments.

Plants can evolve rapidly after pollinator changes, but the response of different floral traits to novel selection can vary. Floral morphology is often expected to show high integration to maintain pollination accuracy, while nectar traits can be more environmentally sensitive. The relative role of genetic correlations and phenotypic plasticity (PP) in floral evolution remains unclear, particularly for nectar traits, and can be studied in the context of recent pollinator changes. Digitalis purpurea shows rapid recent evolution of corolla morphology but not nectar traits following a range expansion with hummingbirds added as pollinators. We use this species to compare PP, heritability, evolvability and integration of floral morphology and nectar in a common garden. Morphological traits showed higher heritability than nectar traits, and the proximal section of the corolla, which regulates access to nectar and underwent rapid change in introduced populations, presented lower integration than the rest of the floral phenotype. Nectar was more plastic than morphology, driven by highly plastic sugar concentration. Nectar production rate showed high potential to respond to selection. These results explain the differential rapid evolution of floral traits previously observed in this species and show how intrafloral modularity determines variable evolutionary potential in morphological and nectar traits.

Use of metatarsal hook plates in the treatment of multifragmentary patellar fractures - A case series.

The surgical management of patellar fractures typically yielded satisfactory results; however, in situations involving multifragmented patellar fractures or those affecting the inferior pole, it became imperative to employ alternative osteosynthesis techniques that enhanced stability, enabled early rehabilitation initiation, prevented implant failure, and avoided reduction loss before fracture consolidation. In this context, an unconventional osteosynthesis alternative was presented, utilizing an anatomically designed hook plate originally intended for the fifth metatarsal. This technique was successfully applied in three patients with multifragmentary patellar fractures, allowing stable fixation of small or marginal fragments through the plate's hooks without compromising vascularity. Fracture consolidation was achieved without reduction loss, and owing to its low profile, patient discomfort and irritation were minimized compared to traditional tension band or wiring techniques. This approach suggested the potential to forego early plate removal, thereby contributing to a more effective management of patellar fractures. Level of evidence: IV.

An unusual case of small bowel volvulus due to pneumatosis cystoides intestinalis: Case report and literature review.

INTRODUCTION AND IMPORTANCE: Pneumatosis cystoides intestinalis (PCI) is an uncommon condition characterized by intramural gas accumulation in the intestinal submucosa. Idiopathic or secondary is presented with non-specific clinical signs; in some cases, diagnosis is incidental. Its acute presentation is uncommon, and surgical management could be performed in selected cases. CASE PRESENTATION: We present the case of an 85-year-old woman with 3 days of abdominal pain, 6 months of weight loss, and abdominal distension after meals. Abdominal computed tomography evidenced PCI at the small intestine with changes due to intestinal ischemia and internal mesenteric hernia. Intestinal resection and lateral-lateral mechanical anastomosis were performed with no complications after 90 days of follow-up. CLINICAL DISCUSSION: PCI is an infrequent and benign condition; pathophysiology is, to date, poorly understood. Idiopathic or secondary to other gastrointestinal pathologies are described. The final diagnosis is performed with histopathological analysis. Nevertheless, in some cases, the benign nature could be presented as an acute abdomen, and surgical management should be in the physician's armamentarium. CONCLUSION: PCI is an uncommon and benign entity. Nevertheless, in some cases, it could be presented as an acute abdomen. The surgical approach is appropriate, safe, and feasible.

Aplicación de las nuevas tecnologías en Atención Primaria en el control del paciente con sobrepeso u obesidad y factores de riesgo cardiovascular / Application of new technologies in Primary Care to monitor overweight or obese patients with cardiovascular risk factor

El objetivo es evaluar un seguimiento telemático (web o aplicación [app]) para pacientes con sobrepeso/obesidad y otros dos factores de riesgo cardiovascular: hipertensión arterial (HTA), dislipemia, diabetes mellitus (DM), sedentarismo, consumo tabáquico. Diseño: es un estudio de intervención con asignación aleatoria al grupo intervención (web o app) y al grupo control. Emplazamiento: centros de salud rurales y urbanos, docentes y no docentes, del Sector Zaragoza I. Participantes: 261 personas con índice de masa corporal (IMC) > 25 kg/m2 y otros dos factores de riesgo. Intervenciones: seguimiento de 18 meses con puntos de corte al inicio, 1, 6, 12 y 18 meses. Las mediciones principales son peso, tensión arterial, consumo tabáquico, eventos cardiovasculares, calidad de vida y bioquímica. Resultados: el grupo control finalizó el estudio en mayor proporción (79% versus 14%). El grupo control consiguió una pérdida del 8% de la mediana de peso al año y el grupo intervención un 5%. A los 6 meses, el grupo control logró disminuir el 7% la tensión arterial sistólica y el 5% la diastólica. La hemoglobina glicosilada (HbA1c) descendió un 1% en el grupo control y un 0,5% en el grupo intervención (test de Wilcoxon: 10; p = 0,089). El colesterol de lipoproteínas de baja densidad (cLDL) del grupo control descendió 9 mg/dL, y el del grupo intervención, 7 mg/dl (test de Wilcoxon: 1.089; p = 0,018). El hábito tabáquico disminuyó en todos los grupos (test de Wilcoxon: 21; p = 0,036). El grupo control presentó mayor prevalencia de eventos cardiovasculares. La calidad de vida mejoró en todos los grupos (test Wilcoxon: 979; p = 0,041). Conclusiones: las/los pacientes que acuden al centro de salud para un seguimiento de peso consiguen mejores resultados que si el seguimiento se hace de forma telemática.(AU)

The aim was to evaluate remote assistance (Web or App) for overweight/obese patients with two extra cardiovascular risk factors: hypertension, dyslipidemia, diabetes, smoking, sedentary lifestyle. Design: intervention study using random assignment for Web Group and App Group. The App Group was subsequently selected. Location: urban and rural health centres, teaching and non-teaching centres, in the Zaragoza I health area. Subjects: 261 people with BMI> 25 Kg/m2 and two extra cardiovascular risk factors. Interventions: 18 months follow up, initial checkups and after 1, 6, 12 and 18 months. The primary endpoints were: weight, blood pressure, tobacco consumption, cardiovascular events, quality of life and blood tests. Results: The control group completed the study in a higher proportion (79% vs 14%). The control and intervention groups attained a loss of 8% in and 5% median weight per year, respectively. After 6 months, the control group managed to reduce systolic and diastolic blood pressure by 7% and 5%, respectively. Glycosidic haemoglobin was 1% and 0.5% lower in the control and intervention groups, respectively (Wilcoxon Test=10; P= 0.089). Both groups reduced tobacco consumption (Wilcoxon=21; P=0.03). The control group had a higher prevalence of cardiovascular events. Quality of life improved (Wilcoxon Test=979; P=0.041). Conclusion: Patients visiting health centres to monitor weight obtain better results than those remotely assisted.(AU)

Retinopatía Diabética y Edema Macular Diabético en Población de Antioquia. Estudio transversal / Diabetic Retinopathy and Diabetic Macular Edema in a population of Antioquia. Cross-sectional study

Resumen Introducción: la diabetes mellitus (DM) es una epidemia mundial. La retinopatía diabética proliferativa (RDP), el edema macular diabético (EMD) y las complicaciones de la diabetes mellitus son las principales causas de discapacidad visual y ceguera en los adultos en la edad productiva. Aproximadamente, 1 de cada 3 personas con DM tiene retinopatía diabética (RD) y 1 de cada 10 tiene RDP o EMD. En el presente estudio se hace énfasis en esta última, siendo el primero con estas características en Colombia. Métodos: estudio transversal descriptivo donde se incluyeron 1.203 pacientes con diagnóstico de DM atendidos en la jornada "No más ciegos por Diabetes" del Hospital San Vicente Fundación de Medellín, en el 2017 y 2018. Se evaluó la presencia de RD y EMD clínico y sus características epidemiológicas en un análisis bivariado. Resultados: del total de pacientes con DM tamizados (1.203), el 5,4 % (65) tenían EMD; dentro de estos, el 7,7 % tenía DM tipo 1 y el 89,2% DM tipo 2. El 10,8 % tenía RDP, 73,8% tenía RD no proliferativo (RDNP). En un 93,8 % se hizo diagnósticos de novo de RD. La mediana del tiempo de la diabetes fue de 14 años, con un rango intercuartílico (RIQ) entre 7 y 19,5. La mediana de la hemoglobina glicosilada (HbA1C) fue de 8,3 % (RIQ: 7,1-11). De 65 pacientes con EMD, 28 (56 ojos de los 130 con EMD) fueron estudiados con tomografía de coherencia óptica (OCT) y al 85,7 % se le confirmó EMD. La mediana del grosor macular central fue de 249 micras (RIQ: 231-341) en los pacientes con EMD por OCT (n = 48 ojos). Conclusión: las complicaciones de la diabetes son más prevalentes en los pacientes con RD. La media del tiempo de aparición de EMD fue similar al tiempo de inicio de las complicaciones microvasculares de la diabetes reportada en la literatura, pero debe ser considerada en el contexto del control metabólico de los pacientes.

Summary Introduction: Diabetes Mellitus (DM) is a worldwide epidemic disease, with significant microvascular compromise. Proliferative diabetic retinopathy (PDR) as well as diabetic macular edema (DME) are currently two of the leading causes of visual impairment and blindness in adults of productive age. Approximately one in three people with DM have diabetic retinopathy (DR), and 1 in 10 have PDR or DME. This study emphasizes in the last one, being the first one with these characteristics in Colombia. Methods: This descriptive cross-sectional study includes 1203 patients diagnosed with DM evaluated in the "No more blindness due to diabetes" diabetic retinopathy-screening program of the San Vicente Foundation Hospital in Medellín between 2017 and 2018. The presence of DR and clinical macular edema with the epidemiologic variables were evaluated in a bivariate analysis. Results: From the total number of patients with DM screened (1203), 5,4% (65) had DME, 7,7% had DM type 1 and 89,2% had DM type 2, 10,8% had PDR and 73.8% had nonproliferative diabetic retinopathy NPDR. Most of the patients (93,8%) were diagnosed de novo with DR. The median illness time was 14 years with interquartile range (IQR) between 7 and 19,5. The median glycosylated hemoglobin (HbA1C) was 8.3% (IQR:7,1-11). Optical coherence tomography (OCT) study was done in 28 out of 65 patients with DME (56 out of 130 eyes with DME), in which 85.7% of patients were confirmed to have DME and the mean central macular thickness was 249 microns (IQR:231-341) (n=48 eyes). Conclusion: DM complications were more frequent in patients suffering from DR. The median onset time of DME symptoms was found to be similar to the time of microvascular complications appear; however, it should be considered along with the patient's metabolic control.

Comprehensive ADM1 Extensions to Tackle Some Operational and Metabolic Aspects in Anaerobic Digestion.

Modelling in anaerobic digestion will play a crucial role as a tool for smart monitoring and supervision of the process performance and stability. By far, the Anaerobic Digestion Model No. 1 (ADM1) has been the most recognized and exploited model to represent this process. This study aims to propose simple extensions for the ADM1 model to tackle some overlooked operational and metabolic aspects. Extensions for the discontinuous feeding process, the reduction of the active working volume, the transport of the soluble compound from the bulk to the cell interior, and biomass acclimation are presented in this study. The model extensions are included by a change in the mass balance of the process in batch and continuous operation, the incorporation of a transfer equation governed by the gradient between the extra- and intra- cellular concentration, and a saturation-type function where the time has an explicit influence on the kinetic parameters, respectively. By adding minimal complexity to the existing ADM1, the incorporation of these phenomena may help to understand some underlying process issues that remain unexplained by the current model structure, broadening the scope of the model for control and monitoring industrial applications.

New findings on the anaerobic co-digestion of thermally pretreated sludge and food waste: laboratory and pilot-scale studies.

Co-digestion of thermally pretreated sewage sludge with food waste is an innovative strategy that could improve the balance and availability of nutrients needed to increase the efficiency of anaerobic digestion in terms of biogas production. In this context, the aim of this research was to evaluate the impact of different proportions of sewage sludge/food waste in laboratory- and pilot-scale reactors. Special focus was placed on the impact of the variability of food waste composition on the behaviour of the pilot digester. Our results show that by adding 40% of co-substrate, a higher biogas production was possible during laboratory operation. Interestingly, using a co-substrate of variable composition had no negative impact on the reactor's stability at pilot-scale, promoting an increase in biogas production through a more efficient use of organic matter. In both the lab and pilot experiences there was an impact on the amount of nitrogen in the digestate compared to digester operating in monodigestion. This impact is more significant as the proportion of co-substrate rises. Overall, our results show that co-digestion of thermally pretreated sewage sludge with food waste allows better management of food waste, especially when their composition is variable.

Eye Salvage with Intra-Arterial and Intra-Vitreal Chemotherapy in Patients with Retinoblastoma: 8-Year Single-Institution Experience in Colombia.

INTRODUCTION: Intra-arterial chemotherapy (IAC) is useful for eye preservation in advanced retinoblastoma (Rb). Intra-vitreal chemotherapy (IvitC) is the latest treatment for vitreous seeds. METHODS: The present study is a retrospective assessment of 100 eyes, treated with primary or secondary IAC alone or with IvitC. We evaluated demographic and clinical variables, eye salvage, associated adverse events, and patient survival. Data were analyzed using descriptive statistics. Kaplan-Meier survival curves and Cox hazard ratios were utilized to assess the effect of demographic and clinical variables over eye salvage. RESULTS: Bilateral Rb was observed in 61% of patients, and 57% of eyes received secondary treatment. Forty eyes needed intra-arterial plus IvitC and 62 presented advanced disease (group D and E). Three- and 5-year ocular survival probabilities were 75 and 68%. We found a higher risk in group D and E eyes and those requiring 2 or more routes for ophthalmic artery catheterization. Patients coming from other countries also showed increased risk. Using primary or secondary treatment, or IvitC, did not affect this risk. Overall rates of survival and eye salvages were 98.8 and 73%, and we had a 100% catheterization success and none ophthalmic arterial occlusions. CONCLUSIONS: In an upper middle-income country such as Colombia, a specialized institution counting with therapeutic alternatives and a multidisciplinary team can reach rates of patient survival and eye salvage similar to those of high-income countries.

Frecuencia de ansiedad y depresión en niñas y adolescentes de la casa de acogida "Miguel León" en el cantón Cuenca, Ecuador / Frequency of anxiety and depression in girls and adolescents from "Miguel León" foster home in Cuenca, Ecuador

INTRODUCCIÓN: La depresión y ansiedad son dos patologías de alto impacto personal, social y económico; su evolución se da en muchos casos desde edades tempranas. La violencia generada dentro del hogar puede provocar la separación de muchos NNA de su núcleo familiar; siendo enviados, la mayoría de las veces, a casas de acogida. Aquellos niños y adolescentes que se encuentran en casas de acogida, tienden a desarrollaron ansiedad, depresión y estrés y estos trastornos desencadenan en dificultades emocionales y mentales a lo largo de su vida. En este contexto, el principal objetivo de este trabajo fue dar a conocer la frecuencia de ansiedad y depresión en niñas y adolescentes de la casa de acogida "Miguel León" del cantón Cuenca, en el 2016, generando estadísticas que permitan sentar las bases para proyectos de protección y estudios futuros. MATERIALES Y MÉTODOS: Estudio de tipo descriptivo, transversal cuantitativo. Con una población de estudio de 35 niñas y adolescentes, en edades de 5 a 18 años, de una casa de acogida. Para la recolección de datos se usaron, la Escala de Ansiedad Infantil de SPENCE y el Inventario CDI. El procesamiento se realizó mediante el programa Microsoft Excel 2010 y el software SPSS 15.0. Los datos se presentan en tablas y gráficos mediante frecuencias y porcentajes. RESULTADOS: La frecuencia de ansiedad fue de 22.86% y la frecuencia de depresión del 17.14%. El rango de edad más prevalente para ambas patologías fue de 10 a 14 años con 62.5% y 50% respectivamente. Tanto en el grupo de NNA con ansiedad como en el grupo con depresión el tiempo de estancia en la casa de acogida fue de 0 a 6 meses para la mayoría (50 y 66.67% respectivamente). CONCLUSIÓN: La frecuencia de depresión en niñas de 5 a 18 años de edad en la casa de acogida fue de 17.14%. La frecuencia de ansiedad en niñas de 5 a 18 años de edad en la casa de acogida fue del 22.86%, valores inferiores a los encontrados en otros estudios. El rango de edad en el que estas enfermedades fueron más prevalentes fue de 10-14 años. Ambos trastornos fueron más prevalentes cuanto menor fue el tiempo de estadía en la casa de acogida.

BACKGROUND: Depression and anxiety are two pathologies of great personal, social and economic impact; in many cases both have an early onset. Domestic violence can separate children and adolescents from their families; being sent, most of the times, to foster homes. Children and adolescents in foster homes tend to develop anxiety, depression and stress triggering lifelong emotional and mental difficulties. In this context, the aim of this study was to determine the frequency of anxiety and depression in girls and female adolescents from "Miguel León" Shelter, Cuenca, during 2016, creating statistical data that will allow setting protection projects and future studies. METHODS: Descriptive, quantitative cross-sectional study. The study population was stablished with 35 girls and adolescents, aged 5 to 18 years, from a foster home. For data collection, the SPENCE Child Anxiety Scale and the CDI Inventory were applied. Data was processed with Microsoft Excel 2010 and SPSS 15.0. Data is presented in charts and graphics using frequencies and percentages. RESULTS: The frequency of anxiety was 22.86% and the frequent of depression was 17.14%. The most prevalent age range for both pathologies was 10 to 14 years old with 62.5% and 50% respectively. In both groups, diagnosed with anxiety and diagnosed with depression, the length of stay in the foster home was 0 to 6 months for the majority of the population ( 50 and 66.67% respectively). CONCLUSIÓN: The frequency of depression in girls aged 5 to 18 years, was 17.14%. The frequency of anxiety in girls aged from 5 to 18 years in the foster home was 22.86%, values lower than those found in other studies. The age range in which both diseases were most prevalent was, 10-14 years old. Both disorders were more prevalent the shorter the time spent in the foster home.

Exploitation of the ADM1 in a XXI century wastewater resource recovery facility (WRRF): The case of codigestion and thermal hydrolysis.

The aim of this study is to test the capability of the anaerobic digestion model n1 (ADM1) to reproduce data from full-scale digesters operated in a wastewater resource recovery facility (WRRF) where both thermal hydrolysis and codigestion with industrial waste are carried out. Furthermore, the potential uses of the model in a WRRF are also described, with particular relevance for plant engineers/operators. The model capability was calibrated and validated with data from full-scale digesters from the Mapocho-Trebal WRRF (Biofactoría) in Santiago, Chile. A success simulation rate, defined as the percentage of experimental values of a certain variable that lies within the simulation band given by a simulation tolerance established by the user/operator, was established to test the capability of the model as objectively as possible. Regarding the full-scale digester fed with thermally pretreated mixed sludge, success rates of 65% for biogas production and 60-100% for other variables were achieved. Regarding the full-scale digester in codigestion mode, the model had a success rate of approximately 60% for predicting the biogas flow for the whole evaluation period, while for the other variables, values between 70 and 100% were attained. The lowest success rates were observed for the volatile fatty acid (VFA) concentration in the digestate. Despite the lack of available data and the number of assumptions that had to be made, the model was demonstrated to be capable of reproducing the behavior of the full-scale reactors. A proper, up-to-date, calibrated and validated model can aid in the decision-making process in a WRRF, for instance, in determining some unmeasured inlet conditions, in improving the resilience of the process and in managing the incorporation of a new cosubstrate into the plant, among others.

Making sense of parameter estimation and model simulation in bioprocesses.

Most articles that report fitted parameters for kinetic models do not include meaningful statistical information. This study demonstrates the importance of reporting a complete statistical analysis and shows a methodology to perform it, using functionalities implemented in computational tools. As an example, alginate production is studied in a batch stirred-tank fermenter and modeled using the kinetic model proposed by Klimek and Ollis (1980). The model parameters and their 95% confidence intervals are estimated by nonlinear regression. The significance of the parameters value is checked using a hypothesis test. The uncertainty of the parameters is propagated to the output model variables through prediction intervals, showing that the kinetic model of Klimek and Ollis (1980) can simulate with high certainty the dynamic of the alginate production process. Finally, the results obtained in other studies are compared to show how the lack of statistical analysis can hold back a deeper understanding about bioprocesses.

The IDH-TAU-EGFR triad defines the neovascular landscape of diffuse gliomas.

Gliomas that express the mutated isoforms of isocitrate dehydrogenase 1/2 (IDH1/2) have better prognosis than wild-type (wt) IDH1/2 gliomas. However, how these mutant (mut) proteins affect the tumor microenvironment is still a pending question. Here, we describe that the transcription of microtubule-associated protein TAU (MAPT), a gene that has been classically associated with neurodegenerative diseases, is epigenetically controlled by the balance between wt and mut IDH1/2 in mouse and human gliomas. In IDH1/2 mut tumors, we found high expression of TAU that decreased with tumor progression. Furthermore, MAPT was almost absent from tumors with epidermal growth factor receptor (EGFR) mutations, whereas its trancription negatively correlated with overall survival in gliomas carrying wt or amplified (amp) EGFR We demonstrated that the overexpression of TAU, through the stabilization of microtubules, impaired the mesenchymal/pericyte-like transformation of glioma cells by blocking EGFR, nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) and the transcriptional coactivator with PDZ-binding motif (TAZ). Our data also showed that mut EGFR induced a constitutive activation of this pathway, which was no longer sensitive to TAU. By inhibiting the transdifferentiation capacity of EGFRamp/wt tumor cells, TAU protein inhibited angiogenesis and favored vascular normalization, decreasing glioma aggressiveness and increasing their sensitivity to chemotherapy.

Addressing the synergy determination in anaerobic co-digestion and the inoculum activity impact on BMP test.

Anaerobic mono-digestion and co-digestion are nowadays widely used in wastewater treatment plants (WWTP). However, the data processing of the conventional biochemical potential test (BMP) carried out to assess potential substrates should be enhanced to reduce the uncertainty of the results. In this study, two methodologies aiming to improve the data processing in anaerobic digestion studies were proposed. The methodologies aimed at the estimation of synergy in anaerobic co-digestion of organic waste and the standardization of the BMP test results by considering the activity of the inoculums under mono-digestion conditions. Both methodologies comprise the application of the Gompertz equation. For the first methodology, four cosubstrates and two types of substrates were used. Regarding synergy estimation, the cosubstrates dairy whey and grease sludge had an impact on the degradation kinetic. In regard to the second methodology, the results indicate that the activity of the inoculums exerts an influence on the BMP analysis, and it should be considered. This can be meaningful when comparing results among studies when different inoculums are used or even for studies where the same inoculum is used but it is taken at different reactor operational moments.

Assessing the stability of anaerobic co-digestion in the context of a WWTP with thermal pre-treatment of sewage sludge. Case study in Chile.

In this study, beverage wastewater (BW) and extended aeration sewage sludge were assessed as co-substrates with both mixed sludge and thermally hydrolyzed sludge as substrates in an anaerobic codigestion (AcoD) process. The methodology is an integrated methodology that comprises a batch test (BMP) and semicontinuous reactor along with microbial diversity analysis. The results showed that in batch conditions, neither significant synergistic nor antagonistic effects were observed on the maximum potential (P) due to the cosubstrates presence. However, synergistic effects on a kinetic parameter (Rm) were observed when BW was used as cosubstrate. Process instability was observed in semi-continuous mode with cosubstrate BW, which was not predicted by the BMP test. As demonstrated in this study, the BMP approach is also not suitable for predicting continuous performance in real systems; however, it can be used to screen an array of substrates. In semi-continuous mode, one can expect to reach values between 50 and 60% of the biogas potential and 20-40% of the maximum production rate achieved in batch tests. The agreement between batch and semi-continuous results is also dependent on the type of inoculum used. The microbial diversity of the system was more influenced by the reactor stability than the presence of cosubstrates. To predict the performance (and stability) of real anaerobic digesters, dynamic models should be employed.

Comparison of performance in an anaerobic digestion process: one-reactor vs two-reactor configurations.

The present work compares two types of configurations for a two-reaction (acidogenesis and methanogenesis) anaerobic digestion model. These configurations are as follows: (i) a single bioreactor, where the acidogenesis and methanogenesis reactions occur inside and, (ii) two bioreactors connected sequentially, where each reaction occurs separately in each reactor. The mathematical models that describe the mentioned configurations are analyzed at steady state, comparing the following criteria: the stability of the processes (stability properties of desired equilibria) and soluble organic matter removal performance (substrate levels at steady states), concluding that separation of the reactions in two bioreactors does not improve the stability of the process nor the soluble organic matter removal capacity, unless the improvement of the growth functions of both microorganism populations is considerably important at the moment of separating them into two reactors.

Mathematical modelling of in-situ microaerobic desulfurization of biogas from sewage sludge digestion.

Microaeration can be used to cost-effectively remove in-situ H2S from the biogas generated in anaerobic digesters. This study is aimed at developing and validating an extension of the Anaerobic Digestion Model n°1 capable of incorporating the main phenomena which occurs during microaeration. This innovative model was implemented and tested with data from a pilot scale digester microaerated for ∼ 200 d. The results showed that despite the model's initial ability to predict the digester's behavior, its predicted performance was improved by calibrating the most influential parameters. The model's prediction potential was largely enhanced by adding retention parameters that account for the activity of sulfide oxidizing bacteria retained inside the anaerobic digester, which have been consistently shown to be responsible for a large share of the H2S removed.

[Compliance of latent tuberculosis infection treatment in a cohort of TB contacts]. / Cumplimiento del tratamiento de la infección tuberculosa latente en una cohorte de contactos de enfermos de tuberculosis.

OBJECTIVE: Compliance with the treatment of Latent Tuberculous Infection (ITL) is a determining factor in the control of tuberculosis. The objective of this study was to estimate the acceptance and compliance of the ITL treatment, and associated factors in contacts of patients with tuberculosis in Lleida. METHODS: Epidemiological analytical observational study, of a retrospective cohort follow-up, since the 1 January 2015 to 31 December 2016. The Participants were contacts of patients with tuberculosis in Lleida. Variables of the index case and independent and dependent variables (acceptance and compliance of the treatment) of contacts were studied through univariate and bivariate analysis. The strength of association was studied with odds ratio (OR) and confidence interval (IC) of 95% they were adjusted by a multivariate regression model. RESULTS: 69.1% of tuberculosis cases had a contact study, and 47.5% had at least one contact with prescription of preventive treatment. The treatment was accepted by 94.5% of contacts, and only 70.3% finalized this treatment. The completion was more frequent in patients who knew the meaning of latent tuberculosis infection treatment (ORa: 2.0; CI: 95% 1.0-4.1).

OBJETIVO: El cumplimiento del tratamiento de la Infección Tuberculosa Latente (ITL) es un factor determinante del control de la tuberculosis. El objetivo de este trabajo fue estimar la aceptación y el cumplimiento del tratamiento de la ITL y factores asociados en contactos de enfermos con tuberculosis en Lleida. METODOS: Estudio epidemiológico analítico observacional de seguimiento de una cohorte retrospectiva, desde el 1 de enero de 2015 al 31 de diciembre de 2016. Los participantes fueron los contactos de enfermos con tuberculosis de Lleida. Se estudiaron variables del caso índice y variables independientes y dependientes (aceptación y cumplimiento de la ITL) de los contactos, a través del análisis univariado y multivariado. La fuerza de asociación se estudió con el odds ratio (OR) y su intervalo de confianza (IC) del 95% y se ajustaron mediante modelos de regresión logística. RESULTADOS: El 69,1% de los casos de tuberculosis poseían estudio de contactos, y el 47,5% tenían algún contacto con prescripción de tratamiento preventivo. El 94,5% de los contactos aceptó el tratamiento de la ITL, y éste fue finalizado por el 70,3%. El cumplimiento fue más frecuente en los pacientes que conocían el significado del tratamiento de la ITL (ORa: 2,0; IC: 95% 1,0-4,1). CONCLUSIONES: En relación a la aceptación/cumplimiento del tratamiento de la ITL, destaca la influencia positiva de poseer conocimientos sobre la infección y su tratamiento. Los profesionales de Atención Primaria deberían proporcionar mayor educación sanitaria con el fin de mejorar el cumplimiento terapéutico de la ITL.

A need for a standardization in anaerobic digestion experiments? Let's get some insight from meta-analysis and multivariate analysis.

An important variability in the experimental results in anaerobic digestion lab test has been reported. This study presents a meta-analysis coupled with multivariate analysis aiming to assess the impact of this experimental variability in batch and continuous operation at mesophilic and thermophilic anaerobic digestion of waste activated sludge. An analysis of variance showed that there was no significant difference between mesophilic and thermophilic conditions in both continuous and batch conditions. Concerning the operation mode, the values of methane yield were significantly higher in batch experiment than in continuous reactors. According to the PCA, for both cases, the methane yield is positive correlated to the temperature rises. Interestingly, in the batch experiments, the higher the volatile solids in the substrate was, the lowest was the methane production, which is correlated to experimental flaws when setting up those tests. In continuous mode, unlike the batch test, the methane yield is strongly (positively) correlated to the organic content of the substrate. Experimental standardization, above all, in batch conditions are urgently necessary or move to continuous experiments for reporting results. The modeling can also be a source of disturbance in batch test.

Modelling of an anaerobic plug-flow reactor. Process analysis and evaluation approaches with non-ideal mixing considerations.

This study shows the implementation of the Anaerobic Digestion Model (ADM1) in an anaerobic plug-flow reactor (PFR) with two approaches based on the use of consecutive continuous stirred tank reactors (CSTR) connected in serie for considering non-ideal mixing. The two-region (TR) model splits each CSTR into two regions, while the particulate retention (PR) model adds a retention parameter. The models were calibrated and validated based on experimental data from a bench-scale reactor treating cow manure. The PFR conventional model slightly outperformed the non-ideal mixing approaches. However, the PR model showed an increase in biomass retention time treating high solid content substrate. Biogas production was not sensitive to variations of the mixing parameters. The liquid fraction content was better represented by the PR model than the PFR and TR models. The study shows how reactor modelling is useful for monitoring and supervising biogas plants.