Magnetic carbon composites as recycling electron shuttles on anaerobic biotransformations

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] The unique properties of magnetic nanoparticles (MNP), such as high surface area, magnetic, sorption and catalytic characteristics, make them very versatile for many applications in different areas including environmental remediation, as catalysts, adsorbents, immobilising agents for microorganisms and enzymes, and as supports for biofilm growth and water disinfectants. In order to improve their stability and to introduce additional surface properties and functionalities, MNP can be coated with carbon materials (CM) due to their chemical stability, biocompatibility and possibility of tailoring their textural and surface chemical properties for specific applications [1]. We have previously proved that various CM, including activated carbon, carbon xerogels and carbon nanotubes (CNT), can be used as redox mediators (RM) in anaerobic biotransformation, accelerating the electron transfer and, consequently, the reduction rates of organic compounds [1,2]. The combination of CM with MNP offers the possibility of creating magnetic carbon composites with synergistic properties: the adsorptive and catalytic properties of both and the magnetic character of MNP, improving the material performance and rendering it easier to be retained and recovered, by applying a magnetic field. [...]info:eu-repo/semantics/publishedVersio

Performance of Graphene/Polydimethylsiloxane Surfaces against S. aureus and P. aeruginosa Single- and Dual-Species Biofilms

The increasing incidence of implant-associated infections has prompted the development of effective strategies to prevent biofilm formation on these devices. In this work, pristine graphene nanoplatelet/polydimethylsiloxane (GNP/PDMS) surfaces containing different GNP loadings (1, 2, 3, 4, and 5 wt%) were produced and evaluated on their ability to mitigate biofilm development. After GNP loading optimization, the most promising surface was tested against single- and dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. The antibiofilm activity of GNP/PDMS surfaces was determined by the quantification of total, viable, culturable, and viable but nonculturable (VBNC) cells, as well as by confocal laser scanning microscopy (CLSM). Results showed that 5 wt% GNP loading reduced the number of total (57%), viable (69%), culturable (55%), and VBNC cells (85%) of S. aureus biofilms compared to PDMS. A decrease of 25% in total cells and about 52% in viable, culturable, and VBNC cells was observed for P. aeruginosa biofilms. Dual-species biofilms demonstrated higher resistance to the antimicrobial activity of GNP surfaces, with lower biofilm cell reductions (of up to 29% when compared to single-species biofilms). Still, the effectiveness of these surfaces in suppressing single- and dual-species biofilm formation was confirmed by CLSM analysis, where a decrease in biofilm biovolume (83% for S. aureus biofilms and 42% for P. aeruginosa and dual-species biofilms) and thickness (on average 72%) was obtained. Overall, these results showed that pristine GNPs dispersed into the PDMS matrix were able to inhibit biofilm growth, being a starting point for the fabrication of novel surface coatings based on functionalized GNP/PDMS composites

Production and Characterization of Graphene Oxide Surfaces against Uropathogens

Graphene and its functionalized derivatives have been increasingly applied in the biomedi-cal field, particularly in the production of antimicrobial and anti-adhesive surfaces. This study aimed to evaluate the performance of graphene oxide (GO)/polydimethylsiloxane (PDMS) composites against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. GO/PDMS composites containing different GO loadings (1, 3, and 5 wt.%) were synthesized and characterized regarding their morphol-ogy, roughness, and hydrophobicity, and tested for their ability to inhibit biofilm formation under conditions that mimic urinary tract environments. Biofilm formation was assessed by determining the number of total and culturable cells. Additionally, the antibacterial mechanisms of action of GO were investigated for the tested uropathogens. Results indicated that the surfaces containing GO had greater roughness and increased hydrophobicity than PDMS. Biofilm analysis showed that the 1 wt.% GO/PDMS composite was the most effective in reducing S. aureus biofilm formation. In oppo-sition, P. aeruginosa biofilms were not inhibited by any of the synthesized composites. Furthermore, 1% (w/v) GO increased the membrane permeability, metabolic activity, and endogenous reactive oxygen species (ROS) synthesis in S. aureus. Altogether, these results suggest that GO/PDMS com-posites are promising materials for application in urinary catheters, although further investigation is required

PROP1 and CTNNB1 expression in adamantinomatous craniopharyngiomas with or without β-catenin mutations

INTRODUCTION: Activating mutations in exon 3 of the β-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between β-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the β-catenin gene was screened for mutations, and the expression of the β-catenin gene and PROP1 was evaluated. β-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and β-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and β-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the β-catenin gene were identified in 64% of the adamantinomatous craniopharyngiomas samples. Evidence of β-catenin gene overexpression was found in 71% of the tumors with β-catenin mutations and in 40% of the tumors without mutations, and β-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of β-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear β-catenin staining pattern regardless of the presence of a bcatenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort

Estudo do comportamento da dilatação térmica do compósito Mg-B(20%)

O compósito de Mg-B(20%) apresenta aplicações relacionadas à área aeronáutica/aeroespacial, conforme seus históricos de utilização relatados e avaliados por alguns autores, devido a suas propriedades, em especial a relação resistência /peso. O foco do estudo realizado foi levantar pormenorizadamente seu comportamento de expansão térmica para taxas controladas de adição de calor e ciclos térmicos de trabalho. Os resultados mostraram-se dentro do esperado para esta espécie de material, ou seja, as fibras são mais solicitadas numa faixa de temperatura e orientações e a matriz passa a ter maior predomínio global em outras faixas e orienta- ções, o que é comprovado no decorrer deste estudo experimental

Coronavirus Disease 2019 and Human Reproduction: A Changing Perspective

Since the outbreak of severe acute respiratory coronavirus 2 (SARS-CoV-2), the coronavirus disease 2019 has had a wide range of effects on human health. This paper summarizes the data related to the effects of the SARS-CoV-2 infection on human reproduction. Both the male and female reproductive tract express high levels of receptors and proteins needed for viral cell entry. There is presently no evidence that gametes are affected by the infection. Male fertility may be temporarily reduced due to inflammatory responses following infection. The endometrium is highly susceptible to SARS-CoV-2 cell entry; however, it remains unclear whether this could alter receptivity and embryo implantation. Menstrual cycle changes were reported in women who experienced severe infection; however, they tended to be reversible. For couples undergoing assisted reproduction treatment, the pandemic led to a significant psychological burden, with changes in lifestyle that could directly affect the success of the treatment. Human reproduction societies recommend screening all patients prior to cycle initiation and avoiding treatment of women with severe comorbidities until the pandemic is under control. Finally, for pregnant women, it is expected that the infection is more severe in women in the third trimester and in those with comorbidities. Those who are symptomatic for SARS-CoV-2 are more likely to have increased rates of prematurity and intrapartum fetal distress than those who are asymptomatic. Vertical transmission cannot be completely ruled out, but neonatal infection rates are low. Vaccination appears to be safe and is indicated for use in pregnant and lactating women because the benefits outweigh the risks

Ciprofloxacin removal catalysed by conductive carbon materials

Current wastewater treatment technologies are not effective in the removal of pharmaceuticals. In anaerobic bioreactors, the electrons produced during the oxidation of organic matter can potentially be used for the biological reduction of pharmaceuticals. However, these reactions occur generally at a slow rate, due to electron transfer limitations, and might be accelerated through redox mediators (RM). Carbon nanomaterials (CM) have been effective RM in the biological reduction of other pollutants. For instance, CNT@2%Fe were found to increase 76-fold the biological reduction of Acid Orange 10. The magnetic properties of those composites allow their easier recover after the process by using a magnetic field. In this study, CNT and CNT@2%Fe were studied in the anaerobic removal of Ciprofloxacin (CIP). Furthermore, the potential contribution of adsorption and biodegradation processes for CIP removal was assessed. Toxicity assessment is highly important as it is desired that the products formed after the process are not more toxic than the initial compound. Moreover, the evaluation of the possible contribution of nanomaterials used in the process for the final toxic effect of threated solution, is crucial. In this sense, the detoxification of the treated solutions was evaluated towards Vibrio fischeri.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

The effects of two early parenting interventions on child aggression and risk for violence in Brazil (The PIÁ Trial): protocol for a randomised controlled trial

Background Children in many low- and middle-income countries (LMICs) are at high risk for exposure to violence and later violent behaviour. The World Health Organization has declared an urgent need for the evaluation and implementation of low-cost parenting interventions in LMICs to prevent violence. Two areas of significant early risk are harsh parenting and poor child cognitive and socio-emotional development. Parenting interventions suitable for LMIC contexts have been developed targeting these risk factors and have been shown to have promising effects. However, their impact on child aggression, a key precursor of violence, has yet to be determined. The Pelotas Trial of Parenting Interventions for Aggression (PIÁ) has been designed to address this issue. Methods We are conducting a randomised controlled trial to evaluate two early parenting interventions for mothers of children aged between 30 and 42 months in a Brazilian city. The first of these, dialogic book-sharing (DBS), aims to promote child cognitive and socio-emotional development; and the second, the ACT Raising Safe Kids Program (ACT), is designed to reduce harsh parenting. These interventions are being compared with a control group receiving neither intervention. Three hundred and sixty-nine families in a birth cohort are being randomly allocated to one of the three groups (DBS, ACT, Control). Facilitators deliver the interventions to groups of five to 10 mothers at weekly sessions for 8 weeks in DBS and 9 weeks in ACT. Independent assessments of parenting and child development are being made before the interventions, shortly afterwards, and at follow-up 6 months later. The primary outcome is child aggression, and the two main secondary outcomes are: (1) child cognitive and socio-emotional development and (2) harsh parenting. Longer-term outcomes will be investigated as the birth cohort is followed into late childhood, adolescence, and adulthood. Discussion The Pelotas Trial of Parenting Interventions for Aggression (PIÁ) aims to evaluate the impact of two early parenting interventions on child aggression and several other key risk factors for the development of violence, including aspects of parenting and child cognition and socio-emotional functioning. The study is being carried out in a LMIC context where violence constitutes a major social and health burden. Since the two interventions are brief and, with modest levels of training, readily deliverable in LMIC settings, a demonstration that they benefit parenting and reduce risk factors for violence would be of major significance

Effects of Early Changes in Organ Dysfunctions on the Outcomes of Critically Ill Patients in Need of Renal Replacement Therapy

INTRODUCTION: Acute kidney injury usually develops in critically ill patients in the context of multiple organ dysfunctions. OBJECTIVE: To evaluate the effect of changes in associated organ dysfunctions over the first three days of renal replacement therapy on the outcomes of patients with acute kidney injury. METHODS: Over a 19-month period, we evaluated 260 patients admitted to the intensive care units of three tertiary-care hospitals who required renal replacement therapy for > 48 h. Organ dysfunctions were evaluated by SOFA score (excluding renal points) on the first (D1) and third (D3) days of renal replacement therapy. Absolute (A-SOFA) and relative (D-SOFA) changes in SOFA scores were also calculated. RESULTS: Hospital mortality rate was 75%. Organ dysfunctions worsened (A-SOFA>0) in 53%, remained unchanged (A-SOFA=0) in 17% and improved (A-SOFA<0) in 30% of patients; and mortality was lower in the last group (80% vs. 84% vs. 61%, p=0.003). SOFA on D1 (p<0.001), SOFA on D3 (p<0.001), A-SOFA (p=0.019) and D-SOFA (p=0.016) were higher in non-survivors. However, neither A-SOFA nor D-SOFA discriminated survivors from non-survivors on an individual basis. Adjusting for other covariates (including SOFA on D1), A-SOFA and D-SOFA were associated with increased mortality, and patients in whom SOFA scores worsened or remained unchanged had poorer outcomes. CONCLUSIONS: In addition to baseline values, early changes in SOFA score after the start of renal replacement therapy were associated with hospital mortality. However, no prognostic score should be used as the only parameter to predict individual outcomes