Use of spray nozzles to recover dissolved methane from an Upflow Anaerobic Sludge Blanket (UASB) reactor effluent

Methane is a powerful greenhouse gas and a source of energy. Recovering this gas means lower greenhouse gas emission and potential reduction of energetic costs. The lack of full-scale results, the use of different methodologies to detect dissolved methane (d-CH₄) and the fact that no process to remove d-CH₄ from anaerobic effluents is energetically or economically viable at full-scale urged a different approach to the problem. To avoid methodological interference and facilitate comparison of results the Standard Test Method number D8028-17 published by ASTM International can be used to determine d-CH₄. The use of real anaerobic reactor effluent also helps results to be compared. In this study, 80 samples from a full-scale anaerobic reactor showed an average concentration of dissolved methane of 14.9 mg·L^-1, meaning an emission of 229 kg of CO₂ eq·h^-1 and an average of 113.5 kW wasted. Using spray nozzles, an alternative to the methods being researched, the average methane recovery was 11.5 mg·L^-1 of CH₄, an efficiency of 81.6%, meaning 177 kg of CO₂ eq·h^-1 emissions avoided and 87.9 kW of recoverable energy.

Is resveratrol a prospective therapeutic strategy in the co-association of glucose metabolism disorders and neurodegenerative diseases?

Objectives: The mechanism behind the progression of Mild Cognitive Impairment (MCI) to Alzheimer's disease (AD) remains poorly understood. However some evidence pointed out that the co-occurrence of metabolic conditions affecting glucose homeostasis, as type 2 diabetes mellitus (T2DM), may be an important catalyst in this context. Notably, candidate drugs which modulate common pathways in the development of MCI-to-AD mediated by T2DM may offer likely therapy for AD. Nonetheless, limited pharmacological alternatives that modulate common pathways in T2DM, MCI, and AD are available. In the recent decades, studies have shown that resveratrol may act as a neuroprotective compound, but little is known about its potential in improving cognitive and metabolic aspects associated with AD progression mediated by the co-association between TDM2-MCI.Methods: In this review, we discuss possible protective mechanisms of resveratrol on shared pathways associated with AD progression mediated by T2DM-MCI co-occurrence.Results: Some studies indicated that insulin resistance and hyperglycemia may be also a T2DM risk factor for the progression of MCI-to-AD, promoting alterations in metabolic pathways associated with neuronal plasticity, and increasing pro-inflammatory environment. Interestingly, basic research and clinical trials indicate that resveratrol may modulate those pathways, showing a potential neuroprotective effect of this polyphenol.Conclusion: Therefore, there is not enough clinical data supporting the translational therapeutic use of resveratrol in this scenario.

Using hypothesis testing on the mass-transfer effect with sulfate removal as an application

Sulfate and chemical oxygen demand removal by an anaerobic batch reactor treating of acid mine drainage is modelled. Available models are abundant but excessively complex, with large numbers of free parameters. Here, maximum likelihood and chi-squared hypothesis tests are applied to three simple models, with Malthus-Monod and Fick description, in increasing order of complexity: (i) planktonic single population (of sulfate-reducing bacteria); (ii) planktonic double-competing populations (adding fermentative bacteria); (iii) granule bound double-competing populations. The data set consists of 6 time profiles, sampled from 120 days of operation after stabilization of the reactor in pH 4. Single population is refuted by all profiles, in which the sulfate reduction is 72% larger than fermentatives. The planktonic double-competing population description is refuted at 119 days, with inner granule diffusion rate as low as 10% of the previous period. The results showed that, after an operation time, the influence of mass transfer became more evident and the incorporation of Fick's law in the model was fundamental to the description of this trend. All tests and inferences are performed at the 90% confidence interval due to large systematic uncertainties in the data.

Survival recovery rates by six clonal lineages of Daphnia longispina after intermittent exposures to copper

Natural populations are commonly exposed to sequential pulses of contaminants. Accordingly, this study aimed at testing the existence of an association between the tolerance to lethal levels of copper (Cu) and the survival recovery ability from pulsed partially lethal copper exposures in six clonal lineages of Daphnia longispina. It was hypothesized that the most tolerant genotypes would be the ones exhibiting a faster survival recovery from a pulsed contaminant exposure. For each clonal lineage, the intensity of pulses corresponded to the respective concentration of Cu causing 30% of mortality after 24h of exposure (LC_30,24h). The initial hypothesis was not corroborated: obtained results showed no association between survival recovery and lethal tolerance to Cu. Nevertheless, some patterns could be detected. Firstly, the most sensitive lineages to lethal levels of copper revealed a faster survival recovery from a first Cu pulse comparatively to the most tolerant ones, though they were the most sensitive to a second pulse exposure. Secondly, the most tolerant lineages, though being more tolerant to a second exposure, exhibited the lowest survival recovery capacity after exposure to a first pulse of Cu. However, differences in the survival recovery capacity of the six clonal lineages after the exposure to the two pulses of Cu were not observed. Increasing the duration of the recovery period from 24h to 72h did not significantly alter mortality rates, except for the most sensitive and most tolerant clonal lineages. The results here obtained suggests that standard lethality assays may sub-estimate the toxicity of chemicals under realistic exposure scenarios, since sequential pulses are not infrequent in natural conditions.

Differential Age-Dependent Mitochondrial Dysfunction, Oxidative Stress, and Apoptosis Induced by Neonatal Hypoxia-Ischemia in the Immature Rat Brain

Neonatal hypoxia-ischemia (HI) is among the main causes of mortality and morbidity in newborns. Experimental studies show that the immature rat brain is less susceptible to HI injury, suggesting that changes that occur during the first days of life drastically alter its susceptibility. Among the main developmental changes observed is the mitochondrial function, namely, the tricarboxylic acid (TCA) cycle and respiratory complex (RC) activities. Therefore, in the present study, we investigated the influence of neonatal HI on mitochondrial functions, redox homeostasis, and cell damage at different postnatal ages in the hippocampus of neonate rats. For this purpose, animals were divided into four groups: sham postnatal day 3 (ShP3), HIP3, ShP11, and HIP11. We initially observed increased apoptosis in the HIP11 group only, indicating a higher susceptibility of these animals to brain injury. Mitochondrial damage, as determined by flow cytometry showing mitochondrial swelling and loss of mitochondrial membrane potential, was also demonstrated only in the HIP11 group. This was consistent with the decreased mitochondrial oxygen consumption, reduced TCA cycle enzymes, and RC activities and induction of oxidative stress in this group of animals. Considering that HIP3 and the sham animals showed no alteration of mitochondrial functions, redox homeostasis, and showed no apoptosis, our data suggest an age-dependent vulnerability of the hippocampus to hypoxia-ischemia. The present results highlight age-dependent metabolic differences in the brain of neonate rats submitted to HI indicating that different treatments might be needed for HI newborns with different gestational ages.

Gyroxin, a toxin from Crotalus durissus terrificus snake venom, induces a calcium dependent increase in glutamate release in mice brain cortical synaptosomes

Gyroxin is a thrombin-like toxin obtained from the venom of the South American rattlesnake, Crotalus durissus terrificus. Literature has reported "gyroxin syndrome" characterized, in mice, as series of aberrant motor behavior, known as barrel rotation, mainly after intraperitoneal administration. Despites several studies, a physiological mechanism of "gyroxin syndrome" are still not completely understood. In this context, alterations on the central nervous system (CNS), especially causing neurotoxic events, are pointed out as likely candidates. Then, we decided to investigate whether gyroxin induces alterations in glutamate release, one of the most important neurotransmitter involved in neurotoxicity. For that, we performed all experiments, in vitro, using a model of mice brain cortical synaptosomes. Notably, our results indicate that the administration of gyroxin on purified presynaptic brain cortical terminals resulted in an extracellular Ca²⁺- dependent raise in glutamate release. Indeed, our results also showed that gyroxin increases intrasynaptosomal calcium (Ca²⁺) levels through acting on voltage gated calcium channels (VGCC), specifically N and P/Q subtypes. Moreover, our data show that gyroxin increases exocytosis rate. Interestingly, these data suggest that gyroxin might induce neurotoxicity by increasing glutamate levels. However, future investigations are needed in order to elucidate the nature of the following events.

Primary health care attributes of family health teams with and without family physician

Background

The four essential attributes of primary health care (PHC): access, longitudinality, comprehensiveness and coordination, guide the professional practices of service management and also the professionals of the family health strategy teams. Family medicine residence (FMR) is the speciality that trains medical practitioners capable of acting properly in PHC. It develops a person-centred approach, oriented towards the individual, his family and community, which dialogues with the PHC precepts of comprehensive patient care from a social point of view. Thus, the objective of this study was to verify whether there are differences in the PHC attributes perceived by patients treated by teams with FMR doctors and by the others.

Methods

This was an observed cross-sectional study conducted during 2019, which used the Adult Primary Care Assessment Tool (PCATool) to evaluate preliminarily 28 PHC teams working at the city of São Paulo, Brazil. The teams were compared based on 337 patient answers using domains medians and Mann-Whitney tests. The study was approved by the ethics committee.

Results

Eight teams (28.6%) had doctors trained in FMR. The attributes of longitudinality and access were very similar between the two groups. The teams with FMR doctors showed better evaluations in the components: information systems, median 7.78, versus 6.67 (p = 0.391); services available, median 6.52, versus 6.06 (p = 0.086); and services received, median 4.85, versus 3.85 (p = 0.180) of the coordination and comprehensiveness attributes.

Conclusions

We didn't find statistically significant results indicating better PHC attributes of teams with FMR doctors, based on user perception. A continuous study is recommended to follow the evolution of this speciality in the PHC context.

Key messages

FMR is a fundamental key to PHC and must be evaluated continuously. It is necessary to strengthen their insertion in the Brazilian health system and discuss the ways to do so.

Active emigration from climate change-caused seawater intrusion into freshwater habitats

Ecological risk assessment associated with seawater intrusions has been supported on the determination of lethal/sublethal effects following standard protocols that force exposure neglecting the ability of mobile organisms to spatially avoid salinized environments. Thus, this work aimed at assessing active emigration from climate change-caused seawater intrusion into freshwater habitats. To specific objectives were delineated: first, to compute median 12-h avoidance conductivities (AC_50,12h) for freshwater species, and second, to compare it with literature data (LC_{50,48 or 96h}, EC_{50,6 or 21d}) to assess the relevance of the inclusion of stressor-driven emigration into risk assessment frameworks. Four standard test species, representing a broad range of ecological niches - Daphnia magna, Heterocypris incongruens, Danio rerio and Xenopus laevis - were selected. The salt NaCl was used as a surrogate of natural seawater to create the saline gradient, which was established in a 7-compartment system. At each specific LC_{50, 48 or 96h}, the proportion of avoiders were well above 50%, ranging from 71 to 94%. At each LC₅₀, considering also avoiders, populations would decline by 85-97%. Furthermore, for D. magna and X. laevis it was noticed that at the lowest conductivities eliciting mortality, the avoidance already exceeded 50%. The results showed that the emigration from salinity-disturbed habitats exists and that can even be more sensitive than standard endpoints. Looking solely to standard endpoints involving forced exposure may greatly underestimate the risk of local population extinction, because habitat function can be severely disrupted, with subsequent stressor-driven emigration, before any adverse physiological effects at the organism level. Thus, the present study highlights the need to include non-forced exposure testing into ecological risk assessment, namely of salinity-menaced costal freshwaters.

Connective tissue disease-associated interstitial lung disease

BACKGROUND

Connective tissue diseases (CTD) are frequently associated with interstitial lung disease (ILD), significantly impacting their morbidity and mortality.

AIM

Analyze the experience of an autoimmune specialized unit on treating CTD-ILD and characterize the population based on most frequent diseases, imaging patterns, lung function tests results, serology and treatment. Assess mortality and mortality predictors in these patients.

METHODS

Retrospective, descriptive and statistical analysis of the CTD-ILD patients followed up at an autoimmune diseases unit during a 6-year period.

RESULTS

Over the study period, 75 patients with CTD-ILD were treated with a mean follow-up of 49 ± 31 months. The most frequent CTD were systemic sclerosis and rheumatoid arthritis. ILD was diagnosed prior to CTD in 8% of patients and concomitantly in 35%. Nonspecific interstitial pneumonia was the CT pattern in 60% and 35% had an isolated diminished DLCO on lung function tests. Pulmonary hypertension was present in 12% and it was the single most important mortality predictor (OR 14.41, p = 0.006). Corticosteroids are the mainstay of treatment but biologics were prescribed in 39% of the patients (mostly tocilizumab and rituximab). Two scleroderma patients were recently treated with nintedanib.

CONCLUSIONS

ILD is a potential complication of every CTD and can impose a dramatic burden on these patients. The clinical relevance of ILD together with their early expression in the course of the disease underlines the importance of the presence of chest physicians in these units.

Aquatic mesocosms exposed to a fungicide in warm and cold temperate European climate zones: Long-term macroinvertebrate response

At present, the European Union legislation facilitates the use of similar pesticides among European Member States, thereby assuming that biodiversity and ecosystems have equal sensitivities to contaminants throughout the whole of Europe. However, with this assumption, fundamental environmental and biological differences between climatic zones are being ignored in Environmental Risk Assessment. Such differences may strongly influence the behaviour of contaminants, their effects on biodiversity and on the natural functioning of ecosystems. Furthermore, toxicity testing in European ecoregions other than cold-temperate has largely depended on standardized tests using cold-temperate species and conditions, which may lead to a false estimation of risks to organisms from other ecoregions. The present study aim was to determine the response of freshwater macroinvertebrate communities to the fungicide pyrimethanil by conducting aquatic mesocosm experiments in two different ecoregions with different climates: cold-temperate (Frankfurt, Germany) and warm-temperate (Coimbra, Portugal). The results indicate that the community in the cold-temperate climate was more sensitive to the fungicide in comparison to the warm-temperate community. This difference was most likely related to a different rate of fungicide disappearance, which was slower in the colder climate. Based upon our results we discuss important implications for improving Environmental Risk Assessment across climate zones and under present-day global climate change scenarios.

Sensitivity to salinization and acclimation potential of amphibian (Pelophylax perezi) and fish (Lepomis gibbosus) models

Predictions of the International Panel for Climate Changes on sea level rise foresee that the number of coastal regions impacted with salinization will increase in a near future. The present work intended to evaluate the sensitivity to salinization of two freshwater vertebrate species (the frog Pelophylax perezi and the fish Lepomis gibbosus) and their ability to acclimate to this stressor. For this, three specific objectives were targeted: (i) to assess if NaCl may be used as a safe surrogate for risk assessment of seawater (SW) intrusion for freshwater vertebrates; (ii) to evaluate the sensitivity of two freshwater vertebrate models to increased salinity (both due to NaCl or SW); (iii) to determine the capacity of the studied species to acclimate to low levels of salinization. To assess specific objectives (i) and (ii), organisms were exposed to serial concentrations of NaCl or SW dilutions. To assess the capacity of acclimation of both species to salinization, organisms were exposed to low serial concentrations of NaCl during the embryonic development or for a period of two months, respectively, and their sensitivity to NaCl was re-evaluated after this period. Results showed that fish juveniles were more tolerant (96-h LC₅₀ of 21.3 mS cm^-1 for NaCl and 23.6 mS cm^-1 for SW) than frog embryos (96-h LC₅₀ of 10.7 mS cm^-1 for NaCl and 10.7 mS cm^-1 for SW) and tadpoles (96-h LC₅₀ of 19.4 mS cm^-1 for NaCl and 8.72 mS cm^-1 for SW). The fish was able to cope with conductivities of almost one third of SW conductivity, while effect conductivities computed for the amphibian were much lower than SW conductivity (≈ 52 mS cm^-1). The two-fold difference between the sensitivity of the two tested species reinforces the idea that ecological risk assessment for amphibians based on fish toxicity data may underestimate the risk to the former. Acclimation to low levels of salinity caused an increase in tolerance to salinization in P. perezi tadpoles but not in fish.

Sensitivity of freshwater species under single and multigenerational exposure to seawater intrusion

Salinization of coastal freshwater ecosystems is already occurring in some regions of the world. This phenomenon raises serious concerns on the protection of coastal freshwater ecosystems, since many of them support and shelter a large number of species and are considered hotspots of biodiversity. This work intended to assess the adverse effects that salinization, caused by the intrusion of seawater (SW), may pose to freshwater organisms. In this study, three specific goals were addressed: (i) to assess if sodium chloride (NaCl) may be used as a surrogate of natural SW at early-stages of risk assessment; (ii) to identify the most sensitive freshwater species to salinity NaCl; and (iii) to determine if increased tolerance to salinity may be acquired after multigenerational exposure to low levels of salinization (induced with NaCl). A total of 12 standard monospecific bioassays were carried out by exposing organisms from different taxonomic groups (Cyanobacteria: one species, Tracheophyta: two species, Rotifera: one species, Arthropoda: two species and Mollusca: one species) to a series of concentrations of NaCl (ranging from 0.95 to 22.8 mS cm-1) or dilutions of SW (ranging from 1.70 to 52.3 mS cm-1). In general, NaCl exerted similar or higher toxicity than SW, both at lethal and sublethal levels, suggesting that it may be proposed as a protective surrogate of SW for first tiers of salinization risk assessment. Among all tested species, the cyanobacterium Cylindrospermopsis raciborskii, the daphnid Daphnia longispina and the rotifer Brachionus plicatilis were the most sensitive taxa to salinization (EC50 ≤ 4.38 mS cm-1). Given their position at the basis of the food web, it is suggested that small increments of salinity may be enough to induce structural changes in freshwater communities or induce changes in trophic relations. No clear evidences of increased tolerance after multigenerational exposure to low levels of salinity were found.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.

Surgery in ovarian cancer - Brazilian Society of Surgical Oncology consensus

Surgical management in epithelial ovarian cancer (EOC) has a significant impact in overall survival and progression-free survival. The Brazilian Society of Surgical Oncology (BSSO) supported a taskforce of experts to reach a consensus: experienced and specialised trained surgeons, in cancer centres, provide the best EOC surgery. Laparoscopic and/or radiological staging prognosticates the possibility of complete cytoreduction (CC0) and helps to reduce unnecessary laparotomies. Surgical techniques were reviewed. Multidisciplinary input is essential for treatment planning. Quality assurance criteria are proposed and require national consensus. Genetic testing is mandatory. This consensus states the final recommendations from BSSO for management of EOC.

TWEETABLE ABSTRACT

Brazilian Society of Surgical Oncology consensus for surgery in epithelial ovarian cancer patients.

Multigenerational effects of salinity in six clonal lineages of Daphnia longispina

Sea level rise, as a consequence of climate changes, is already causing seawater intrusion in some freshwater coastal ecosystems worldwide. The increase in salinity at these freshwater coastal ecosystems may occur gradually (through groundwater) or abruptly (through extreme weather events). Moreover, many of them are also being altered and threatened by anthropogenic activities. Accordingly, the present study aimed at assessing the multigenerational lethal and sublethal effects caused by increased salinity in six clonal lineages of the freshwater cladoceran Daphnia longispina differing in their sensitivity to lethal levels of copper. Three specific objectives were delineated: i) to compare the lethal and sublethal toxicity of sodium chloride (NaCl) and natural seawater (SW); ii) to evaluate possible multigenerational effects after exposure to low levels of salinity, and iii) to evaluate if an association exists between tolerance to lethal and sublethal levels of salinity and tolerance to metals. Overall, NaCl was found to elicit sublethal effects at lower or similar concentrations than SW, suggesting its use as a protective surrogate of SW in early phases of ecological risk assessment schemes. Multigenerational exposure to conductivities of 0.73±0.015mScm^-1 led to dissimilar responses by the six clonal lineages. Significant associations were found neither between lethal and sublethal endpoints nor between salinity and metals, possibly indicating the absence of common mechanisms responsible to confer metal tolerance and salt stress. However, some clonal lineages presented an inverse sensitivity to lethal levels of NaCl and of copper. These results suggest that natural populations of D. longispina, by exhibiting clonal lineages with differential tolerance to increased salinity, may cope with long-term exposure to small increases of this stressor. However, over time those populations may face the occurrence of genetic erosion due to the loss of the most sensitive genotypes before or after a multigenerational exposure.

Comportamento de Fratura de Estruturas Cerâmicas Monolíticas e Multicamadas Sob Diferentes Condições de Carga

O objetivo do estudo foi verificar o comportamento de fratura de corpos-de-prova (CP) cerâmicos submetidos a dois métodos de ensaio mecânico, flexão biaxial e carga compressiva monotônica. Foram confeccionados 200 CP cerâmicos (120 cimentados e 80 não cimentados), em 4 configurações: CAD-on (e.max ZirCAD + Crystall/Connect + e.max CAD) YLD (e.max ZirCAD + e.max Ceram) LDC monolítico (e.max CAD) YZW monolítico (Zenostar). Os CP (n30) foram cimentados (Multilink N, Ivoclar) em bases de resina epóxica (G10) e submetidos à carga compressiva monotônica (EMIC) com velocidade de 0,5 mm/min, em água destilada (37ºC), o restante dos CP (n20) foram submetidos a flexão biaxial. As falhas foram avaliadas usando princípios de fractografia e transiluminação. Os dados foram analisados por Kurskal-Wallis e teste de Dunn´s que mostraram diferença estatística entre os grupos experimentais (p<0,001). Os grupos mostraram o mesmo ranqueamento estatístico nos dois métodos de teste. Os grupos CAD-on e YZW apresentaram medianas de carga de fratura superiores e estatisticamente semelhantes entre si. O grupo YLD apresentou valores intermediários de carga de fratura, seguido pelo grupo LDC. As falhas nos CP cimentados foram por lascamentos em sua maioria, com exceção do grupo YZW (catastróficas). Para os CP não cimentados as falhas foram catastróficas em sua maioria com exceção do grupo YLD. A YZW e a técnica CAD-on apresentaram melhor comportamento mecânico, independente do método de teste. Os comportamentos de fratura foram diferentes, mas similares aos relatos clínicos.Palavras-chave: Cerâmicas. Estruturas Multicamadas. Cimentação.

Development of in-house lattice-Boltzmann simulator of bioreactors for wastewater treatment: basic concepts and initial results

While computational modelling has increasingly supported wastewater bioreactor engineering, novel numerical techniques have been developed such as the lattice-Boltzmann method (LBM). With vinasse treatment as case study, this work is a first step towards a comprehensive LBM simulator of a continuous-flow anaerobic packed-bed reactor. Extensions from typical models comprise one-dimensional (besides time) dependence, species transport via convection and diffusion, and imposition of either Dirichlet or Danckwerts condition at inlet. The LBM simulator proved to be operational when simulating the bioreactor at different hydraulic retention times (HRTs). Simulated profiles show that stepwise feeding concentrations are smoothed as they are transported towards the bioreactor exit while concentrations increase or decrease in response to generation or degradation kinetics. Good fitting was observed for concentrations of acetic acid (2.1 kg-COD/m³ for HRT = 24 h) and butyric acid (1.3 kg-COD/m³ for HRT = 16 h) at the exit whereas other concentrations were numerically simulated at proper order of magnitude.