Biofilm technology : from support design to reactor operation

The aim of this work was to assess the feasibility of a Sequential Batch Biofilm Reactor (SBBR) to perform carbon and nitrogen removal: from support design to reactor operation. The experimental part was conducted in two phases. In the first phase, different supports were tested to select the most suitable one for SBBR operation. In the second phase, the most appropriate support was used in a SBBR to perform carbon and nitrogen removal. The results demonstrate that the support with the highest internal surface area presented a higher biomass accumulation. Time profiles of nitrogen ions and acetate concentration showed the typical behaviour of a SBBR performing carbon and nitrogen removal. Poly-bhydroxybutyrate (PHB) was formed immediately after acetate depletion and was subsequently consumed for biomass growth, owing to the high oxygen concentration in the reactor

Synthesis and degradation of poly-β-hydroxybutyrate in a sequencing batch biofilm reactor

The aim of this work was the study of poly-β-hydroxybutyrate (PHB) formation and degradation in a sequencing batch biofilm reactor (SBBR). The SBBR was operated in cycles comprising three individual phases: mixed fill, aeration and draw. A synthetic substrate solution with acetate and ammonium was used. PHB was formed during the aeration phase immediately after acetate depletion, and was subsequently consumed for biomass growth, owing to the high oxygen concentration in the reactor. It was observed a combination of suspended and biofilm growth in the SBBR with predominance of the fixed form of biomass (506 Cmmol and 2102 Cmmol, respectively). Maximum PHB fraction of suspended biomass (0.13 Cmol/Cmol) was considerably higher than that of biofilm (0.01 Cmol/Cmol). This may possibly be explained by a combination of two factors: lower mass transfer limitation of acetate and higher fraction of heterotrophs in suspended biomass compared to the ones of biofilm.Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI 2010 (POCI/AMB/61155/2004)Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI BD/19687/9

Impact of biofilm growth in the microbial community composition of a sequencing batch reactor

Conventional activated sludge wastewater treatment plants (WWTP) for carbon and nutrient removal operate at high sludge retention time and, consequently, at a low food to microorganisms ratio. While the first condition is favourable for nitrifying bacteria growth, an excessive growth of certain species of filamentous bacteria often occurs in the presence of the second one. Interestingly, no problems with excessive growth of filamentous bacteria have been reported for the activated sludge process when combined with biofilm growth more than a decade ago. In this context, the present work aims to compare the microbial community composition of two sequencing batch reactors (SBRs) operating in the presence and in the absence of biofilm growth, and to correlate microbial composition with the performance of the reactors. Two SBRs with a working volume of 1.5 L were operated in parallel with a constant cycle time of 4 h, a volume exchange ratio of 0.5 L/L and a resulting hydraulic retention time of 8 h. The duration of the individual operating phases was: 5 min fill, 225 min aerated, 5 min settle and 5 min draw. During the aerated phase airflow was applied through membrane diffusers, causing the reactor contents including the carrier bed to circulate. The SBRs were operated with synthetic water containing acetate as the only carbon source and ammonium as nitrogen source. One SBR was operated just with suspended biomass while the second one combined suspended biomass with biofilm cultivation. The biofilm was formed on a new type of polyethylene support developed by University of Minho, consisting of hollow, star-shaped, carriers with 17 mm external diameter and a height of 10 mm. The bed formed by these carriers had a specific surface area of 407 m2/m3, an average porosity of 0.74 and occupied 20 % of the reactor volume. Grab samples were taken and analyzed for acetate using a HPLC system. Observation of the filamentous microbial and microfauna communities was accomplished by microscope inspection at 100 to 1000X magnification, in fresh samples and after Gram and Neisser staining. The microbial community of the SBR operating just with suspended growth was dominated by fungi micelar growth, while in the other reactor the communities were clearly more complex. The incorporation of carriers for biofilm growth in the other SBR apparently suppressed the excessive growth of fungi. Differences in the microfaunas community were also observed, the SBR operating just with suspended growth showing clearly a delay in the microfauna succession comparing to the other reactor. Despite this, acetate was completely removed in both SBRs

Electrochemical study of butylate: application to the analysis of water

The electroactivity of butylate (BTL) is studied by cyclic voltammetry (CV) and square wave voltammetry (SWV) at a glassy carbon electrode (GCE) and a hanging mercury drop electrode (HMDE). Britton–Robinson buffer solutions of pH 1.9–11.5 are used as supporting electrolyte. CV voltammograms using GCE show a single anodic peak regarding the oxidation of BTL at +1.7V versus AgCl/ Ag, an irreversible process controlled by diffusion. Using a HMDE, a single cathodic peak is observed, at 1.0V versus AgCl/Ag. The reduction of BTL is irreversible and controlled by adsorption. Mechanism proposals are presented for these redox transformations. Optimisation is carried out univaryingly. Linearity ranges were 0.10–0.50 mmol L-1 and 2.0–9.0 µmolL-1 for anodic and cathodic peaks, respectively. The proposed method is applied to the determination of BTL in waters. Analytical results compare well with those obtained by an HPLC method

Ausência de associação entre indicadores de anemia ao nascimento e crescimento de prematuros

OBJECTIVE: To assess the association between iron status at birth and growth of preterm infants. METHODS: Ninety-five premature babies (26 to 36 weeks of gestational age) born from July 2000 to May 2001 in a public hospital in Rio de Janeiro, Southeastern Brazil, were followed up for six months, corrected by gestational age. Iron measurements at birth were available for 82 mothers and 78 children: hemoglobin, hematocrit, mean corpuscular volume and plasma iron. All children received free doses of iron supplement (2 mg/kg/day) during the follow-up period and up to two years of age. Multivariate linear regression analyses with repeated measurements were performed to assess factors associated to linear growth. RESULTS: Growth was more pronounced up to 40 weeks of gestational age, increasing about 1.0 cm/week and then slowing down to 0.75 cm/week. The multivariate analysis showed growth was positively associated with birth weight (0.4 cm/100 g; pOBJETIVO: Avaliar a associação entre indicadores de anemia no nascimento e o crescimento de prematuros. MÉTODOS: Crianças prematuras (26-36 semanas de idade gestacional) (n=95), nascidas de julho de 2000 a maio de 2001, em hospital público do Rio de Janeiro, foram seguidas por seis meses, corrigidos pela idade gestacional. Foram obtidos em 82 mães e 78 crianças os indicadores de anemia: hemoglobina, hematócrito, volume corpuscular médio e ferro plasmático. Os prematuros receberam suplemento de ferro (2 mg/kg/dia) durante o seguimento. Análises de regressão linear multivariadas, com medidas repetidas, avaliaram os fatores associados ao crescimento linear. RESULTADOS: O crescimento dos prematuros foi mais acentuado até as 40 semanas de idade gestacional, com aumento de aproximadamente 1,0cm/semana. Após essa fase, o crescimento foi de 0,75 cm/semana. Na análise multivariada o crescimento associou-se positivamente com o peso ao nascer (0,4 cm/100 g de peso ao nascer;

Molecular genetic analysis of a cattle population to reconstitute the extinct Algarvia breed

<p>Abstract</p> <p>Background</p> <p>Decisions to initiate conservation programmes need to account for extant variability, diversity loss and cultural and economic aspects. Molecular markers were used to investigate if putative Algarvia animals could be identified for use as progenitors in a breeding programme to recover this nearly extinct breed.</p> <p>Methods</p> <p>46 individuals phenotypically representative of Algarvia cattle were genotyped for 27 microsatellite loci and compared with 11 Portuguese autochthonous and three imported breeds. Genetic distances and factorial correspondence analyses (FCA) were performed to investigate the relationship among Algarvia and related breeds. Assignment tests were done to identify representative individuals of the breed. Y chromosome and mtDNA analyses were used to further characterize Algarvia animals. Gene- and allelic-based conservation analyses were used to determine breed contributions to overall genetic diversity.</p> <p>Results</p> <p>Genetic distance and FCA results confirmed the close relationship between Algarvia and southern Portuguese breeds. Assignment tests without breed information classified 17 Algarvia animals in this cluster with a high probability (q > 0.95). With breed information, 30 cows and three bulls were identified (q > 0.95) that could be used to reconstitute the Algarvia breed. Molecular and morphological results were concordant. These animals showed intermediate levels of genetic diversity (MNA = 6.0 ± 1.6, R_t = 5.7 ± 1.4, H_o = 0.63 ± 0.19 and H_e = 0.69 ± 0.10) relative to other Portuguese breeds. Evidence of inbreeding was also detected (F_is = 0.083, <it>P</it> < 0.001). The four Algarvia bulls had Y-haplotypes H6Y2 and H11Y2, common in Portuguese cattle. The mtDNA composition showed prevalence of T3 matrilines and presence of the African-derived T1a haplogroup. This analysis confirmed the genetic proximity of Algarvia and Garvonesa breeds (F_st = 0.028, <it>P</it> > 0.05). Algarvia cattle provide an intermediate contribution (CB = 6.18, CW = -0.06 and D1 = 0.50) to the overall gene diversity of Portuguese cattle. Algarvia and seven other autochthonous breeds made no contribution to the overall allelic diversity.</p> <p>Conclusions</p> <p>Molecular analyses complemented previous morphological findings to identify 33 animals that can be considered remnants of the Algarvia breed. Results of genetic diversity and conservation analyses provide objective information to establish a management program to reconstitute the Algarvia breed.</p

Biocomplementation of SVE to achieve clean-up goals in soils contaminated with toluene and xylene

Soil vapor extraction (SVE) and bioremediation (BR) are two of the most common soil remediation technologies. Their application is widespread; however, both present limitations, namely related to the efficiencies of SVE on organic soils and to the remediation times of some BR processes. This work aimed to study the combination of these two technologies in order to verify the achievement of the legal clean-up goals in soil remediation projects involving seven different simulated soils separately contaminated with toluene and xylene. The remediations consisted of the application of SVE followed by biostimulation. The results show that the combination of these two technologies is effective and manages to achieve the clean-up goals imposed by the Spanish Legislation. Under the experimental conditions used in this work, SVE is sufficient for the remediation of soils, contaminated separately with toluene and xylene, with organic matter contents (OMC) below 4 %. In soils with higher OMC, the use of BR, as a complementary technology, and when the concentration of contaminant in the gas phase of the soil reaches values near 1 mg/L, allows the achievement of the clean-up goals. The OMC was a key parameter because it hindered SVE due to adsorption phenomena but enhanced the BR process because it acted as a microorganism and nutrient source

Sequential application of soil vapor extraction and bioremediation processes for the remediation of ethylbenzene-contaminated soils

Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technologies is presented as a valid option but is not yet entirely studied. This work presents the study of the remediation of ethylbenzene (EB)-contaminated soils, with different soil water and natural organic matter (NOMC) contents, using sequential SVE and BR. The obtained results allow the conclusion that: (1) SVE was sufficient to reach the cleanup goals in 63% of the experiments (all the soils with NOMC below 4%), (2) higher NOMCs led to longer SVE remediation times, (3) BR showed to be a possible and cost-effective option when EB concentrations were lower than 335 mg kgsoil −1, and (4) concentrations of EB above 438 mg kgsoil −1 showed to be inhibitory for microbial activity

Menções sobre o estado nutricional nos rewgistos clínicos de doentes hospitalizados .

Está descrito que a frequência de desnutrição associada à doença (DAD) afecta cerca de 30 a 60% dos doentes no momento da admissão hospitalar e cerca de 10% dos indivíduos na comunidade. A DAD tem vindo a ser associada a graves consequências, como ao maior risco de infecções e de disfunção de órgãos e a um aumento significativo, não só da morbilidade e mortalidade, como da frequência e dos custos com os cuidados de saúde. A falta do reconhecimento e da monitorização dos aspectos relacionados com o estado nutricional, têm sido apontados como factores que contribuem para o aumento da frequência de DAD, durante o internamento hospitalar. Foi objectivo deste estudo avaliar a relevância que é dada a aspectos relacionados com o estado nutricional dos doentes (peso, ingestão alimentar) e saber se os doentes em risco nutricional ou desnutridos serão alvo de maior atenção por parte dos profissionais de saúde. Foi recolhida uma amostra sistemática de seis hospitais portugueses, correspondente a 42-50% do total de camas de cada serviço de internamento. Foram critérios de exclusão a doença crítica, a gravidez, a idade inferior a 18 anos, a incapacidade de aplicação do protocolo de rastreio nutricional e o tempo de internamento inferior a 24h.Recolheram- se dados sócio-demográficos, antropométricos, sobre as menções dos processos clínicos respeitantes ao peso, cuidados alimentares/nutricionais prestados e ingestão alimentar/nutricional dos doentes e aplicou-se uma ferramenta de rastreio nutricional (Nutritional Risk Screening 2002). Em 1152 doentes estudados, a frequência de risco nutricional variou entre os 28,5% e 47,3%, enquanto que a frequência de desnutrição antropométrica oscilou entre 6,3% e 14,9%. Dois em cada três doentes tinha menções acerca de cuidados alimentares/ nutricionais prestados nos processos clínicos, mas apenas um em cada três tinha o seu peso medido e registado. Os doentes desnutridos foram pesados com menor frequência mas a sua alimentação e problemas a ela associados foram monitorizados com maior regularidade. A frequência de DAD, no momento de admissão hospitalar, é muito elevada, enquanto que a de menções relevantes para o estado nutricional é muito escassa. A presente investigação reforça a necessidade de investir na sensibilização dos profissionais de saúde, sobre a importância do rastreio e da prescrição/monitorização da alimentação e do peso dos doentes, na admissão e durante todo o internamento hospitalar.NUTRITIONAL STATUS RECORDING in Hospitalized Patient Notes The prevalence of disease-related malnutrition (DRM) is described to be of 30-60% on admission to hospital, and of 10% in the community. It has been associated with worse clinical outcomes, namely higher morbidity and mortality as well as higher frequency of health care and its associated costs. The lack of screening and monitoring of nutritional status have been said to be risk factors for the increased prevalence of DRM during hospital stay. The aims of this study were to evaluate the importance given by health care professionals to certain aspects related with nutritional status (weight, food intake) of hospital patients and to see if there were any diferences between the under and non undernourished ones. A systematic sample of patients from six hospitals was collected. Pregnancy, paediatric age and critical illness were exclusion criteria as well as incapacity to fulfil nutritional risk screening protocol and length-of-stay less than 24h. Socio-demographic, anthropometric data and clinical notes (e.g. weight, food/nutrient intake) from medical records were collected and Nutritional Risk Screening 2002 protocol was applied. A total of 1152 patients were included in this study.The revalence of nutritional risk varied between 28.5% and 47.3% while undernutrition classified by anthropometrical parameters was considerably lower (6.3% to 14.9%). Two thirds of the patients had their food intake monitored and registered in medical records but only one third were weighted. Undernourished patients had their food intake more frequently monitored but their weight was less frequently measured, than the well-nourished ones. DRM prevalence amongst hospital patients on admission is significantly high. Clinical notes regarding nutritional status is rather infrequent on medical records. This study showed that urges the need to empower health care providers of the importance of the screening and monitoring of weight and food intake, on admission and during hospital stay.info:eu-repo/semantics/publishedVersio

CuMV VLPs Containing the RBM from SARS-CoV-2 Spike Protein Drive Dendritic Cell Activation and Th1 Polarization.

Dendritic cells (DCs) are the most specialized and proficient antigen-presenting cells. They bridge innate and adaptive immunity and display a powerful capacity to prime antigen-specific T cells. The interaction of DCs with the receptor-binding domain of the spike (S) protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pivotal step to induce effective immunity against the S protein-based vaccination protocols, as well as the SARS-CoV-2 virus. Herein, we describe the cellular and molecular events triggered by virus-like particles (VLPs) containing the receptor-binding motif from the SARS-CoV-2 spike protein in human monocyte-derived dendritic cells, or, as controls, in the presence of the Toll-like receptors (TLR)3 and TLR7/8 agonists, comprehending the events of dendritic cell maturation and their crosstalk with T cells. The results demonstrated that VLPs boosted the expression of major histocompatibility complex molecules and co-stimulatory receptors of DCs, indicating their maturation. Furthermore, DCs' interaction with VLPs promoted the activation of the NF-kB pathway, a very important intracellular signalling pathway responsible for triggering the expression and secretion of proinflammatory cytokines. Additionally, co-culture of DCs with T cells triggered CD4+ (mainly CD4+Tbet+) and CD8+ T cell proliferation. Our results suggested that VLPs increase cellular immunity, involving DC maturation and T cell polarization towards a type 1 T cells profile. By providing deeper insight into the mechanisms of activation and regulation of the immune system by DCs, these findings will enable the design of effective vaccines against SARS-CoV-2