Graphene-Based Coating to Mitigate Biofilm Development in Marine Environments

Due to its several economic and ecological consequences, biofouling is a widely recognized concern in the marine sector. The search for non-biocide-release antifouling coatings has been on the rise, with carbon-nanocoated surfaces showing promising activity. This work aimed to study the impact of pristine graphene nanoplatelets (GNP) on biofilm development through the representative marine bacteria Cobetia marina and to investigate the antibacterial mechanisms of action of this material. For this purpose, a flow cytometric analysis was performed and a GNP/polydimethylsiloxane (PDMS) surface containing 5 wt% GNP (G5/PDMS) was produced, characterized, and assessed regarding its biofilm mitigation potential over 42 days in controlled hydrodynamic conditions that mimic marine environments. Flow cytometry revealed membrane damage, greater metabolic activity, and endogenous reactive oxygen species (ROS) production by C. marina when exposed to GNP 5% (w/v) for 24 h. In addition, C. marina biofilms formed on G5/PDMS showed consistently lower cell count and thickness (up to 43% reductions) than PDMS. Biofilm architecture analysis indicated that mature biofilms developed on the graphene-based surface had fewer empty spaces (34% reduction) and reduced biovolume (25% reduction) compared to PDMS. Overall, the GNP-based surface inhibited C. marina biofilm development, showing promising potential as a marine antifouling coating

In-situ fluorescence spectroscopy is a more rapid and resilient indicator of faecal contamination risk in drinking water than faecal indicator organisms

Faecal indicator organisms (FIOs) are limited in their ability to protect public health from the microbial contamination of drinking water because of their transience and time required to deliver a result. We evaluated alternative rapid, and potentially more resilient, approaches against a benchmark FIO of thermotolerant coliforms (TTCs) to characterise faecal contamination over 14 months at 40 groundwater sources in a Ugandan town. Rapid approaches included: in-situ tryptophan-like fluorescence (TLF), humic-like fluorescence (HLF), turbidity; sanitary inspections; and total bacterial cells by flow cytometry. TTCs varied widely in six sampling visits: a third of sources tested both positive and negative, 50% of sources had a range of at least 720 cfu/100 mL, and a two-day heavy rainfall event increased median TTCs five-fold. Using source medians, TLF was the best predictor in logistic regression models of TTCs ≥10 cfu/100 mL (AUC 0.88) and best correlated to TTC enumeration (ρs 0.81), with HLF performing similarly. Relationships between TLF or HLF and TTCs were stronger in the wet season than the dry season, when TLF and HLF were instead more associated with total bacterial cells. Source rank-order between sampling rounds was considerably more consistent, according to cross-correlations, using TLF or HLF (min ρs 0.81) than TTCs (min ρs 0.34). Furthermore, dry season TLF and HLF cross-correlated more strongly (ρs 0.68) than dry season TTCs (ρs 0.50) with wet season TTCs, when TTCs were elevated. In-situ TLF or HLF are more rapid and resilient indicators of faecal contamination risk than TTCs

Synthesis and Anti-Mycobacterium tuberculosis Activity of Imidazo[2,1-b][1,3]oxazine Derivatives against Multidrug-Resistant Strains

The emergence of multidrug-resistant strains of M. tuberculosis has raised concerns due to the greater difficulties in patient treatment and higher mortality rates. Herein, we revisited the 2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine scaffold and identified potent new carbamate derivatives having MIC90 values of 0.18–1.63 μM against Mtb H37Rv. Compounds 47–49, 51–53, and 55 exhibited remarkable activity against a panel of clinical isolates, displaying MIC90 values below 0.5 μM. In Mtb-infected macrophages, several compounds demonstrated a 1-log greater reduction in mycobacterial burden than rifampicin and pretomanid. The compounds tested did not exhibit significant cytotoxicity against three cell lines or any toxicity to Galleria mellonella. Furthermore, the imidazo[2,1-b][1,3]oxazine derivatives did not show substantial activity against other bacteria or fungi. Finally, molecular docking studies revealed that the new compounds could interact with the deazaflavin-dependent nitroreductase (Ddn) in a similar manner to pretomanid. Collectively, our findings highlight the chemical universe of imidazo[2,1-b][1,3]oxazines and their promising potential against MDR-TB

Detección inmunohistoquímica del virus de Epstein-Barr en pacientes con linfoma

El virus de Epstein-Barr es un gammaherpes virus que infecta principalmente a linfocitos B permaneciendo en un estado de latencia en el interior del mismo, pudiendo también infectar a linfocitos T y células epiteliales. La persistencia de la infección viral inmortaliza a los linfocitos y favorece el desarrollo de procesos linfoproliferativos malignos como linfomas. Si bien se conoce que la relación entre la infección crónica del virus y el desarrollo de linfoma, varía de acuerdo al tipo histológico, se incrementa en pacientes inmunocomprometidos y de edad avanzada, la evidencia científica indica no sólo la importancia de este virus como agente infeccioso asociado con la etiología de esta neoplasia, sino también como un marcador asociado a respuesta refractaria y peor supervivencia. El objetivo de este estudio observacional descriptivo, fue detectar la presencia del Epstein-Barr virus por técnicas de inmunohistoquímica empleando anticuerpos monoclonales anti antígeno viral proteína latente de membrana en 86 pacientes con linfoma. La positividad para proteína en el total de pacientes con linfoma fue del 44%, correspondiendo el 20% a pacientes con linfoma de Hodgkin y el 24% a pacientes con linfoma no Hodgkin. La detección del virus en estas enfermedades, contribuye al manejo clínico de las mismas ya que el virus no sólo tiene un rol etiológico, sino además es un marcador pronóstico importante, incluso de interés terapéutico

Leucemia mieloide aguda con t(8; 21)(q22; q22). Reporte de casos

La leucemia mieloide aguda es una neoplasia hematopoyética caracterizada por laproliferación clonal de blastos inmaduros en médulas ósea interfiriendo con sus funcionesnormales. Tiene una supervivencia aproximada de 35% afectando principalmente aadultos mayores de 60 años y niños menores de un año y preferentemente al sexomasculino. Un hallazgo frecuente es la presencia de la translocación cromosómica t (8;21) (q22; q22) que involucra a los genes RUNX1 y RUNX1T1. La detección de estaalteración tiene implicancia diagnóstica y pronóstica de la enfermedad. El objetivo de estetrabajo es describir y reportar dos casos de leucemia mieloide aguda en pacientesmasculinos de 14 y 24 años que presentaron clínica, laboratorio y morfología típicos de laenfermedad pero con edad de aparición no habitual, enfatizando además, el pronósticobueno desde el punto de vista citogenético de esta translocación en ambos casos

Novel Machado-Joseph disease-modifying genes and pathways identified by whole-exome sequencing

Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset-concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases

Safety analysis of software components of a dialysis machine using model checking

The paper describes the practical use of a model checking technique to contribute to the risk analysis of a new paediatric dialysis machine. The formal analysis focuses on one component of the system, namely the table-driven software controller which drives the dialysis cycle and deals with error management. The analysis provided evidence of the verification of risk control measures relating to the software component. The paper describes the productive dialogue between the developers of the device, who had no experience or knowledge of formal methods, and an analyst who had experience of using the formal analysis tools. There were two aspects to this dialogue. The first concerned the translation of safety requirements so that they preserved the meaning of the requirement. The second involved understanding the relationship between the software component under analysis and the broader concern of the system as a whole. The paper focuses on the process, highlighting how the team recognised the advantages over a more traditional testing approach.This work has been funded by: EPSRC research grant EP/G059063/1: CHI+MED (Computer-Human Interaction for Medical Devices). It has also been financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme, and by National Funds through the FCT - Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) within project POCI-01-0145-FEDER-006961

Using Conducting Polymers as Active Agents for Marine Antifouling Paints

Antifouling coatings were prepared with paints containing polyaniline (PAni) and derivatives as active pigment, and evaluated by antifouling performance on metallic or polyvinyl chloride substrates. The paints, PAni and its derivatives were characterized by FT-IR spectrophotometry, thermogravimetric analysis, electrical conductivity and scanning electron microscopy. Coatings were also characterized by salt spray, leaching and erosion tests. Antifouling coatings’ performance was evaluated by immersion tests in a marine environment or in fresh water. Paints containing PAni-ES, PAni/DBSA and SPAN, and a co-biocide PyZn, showed antifouling performance similar to a commercial antifouling paint

Brazil in the Era of Fascism: The “New State” of Getúlio Vargas

The New State established in Brazil by Getúlio Vargas (1937–1945) is the most important case of the institutionalisation of a dictatorship of the fascism era in Latin America. During this time, an impressive spectrum of authoritarian regimes was established, some of which were very instable and poorly institutionalised, while others were more consolidated. Roger Griffin coined the concept of para-fascism for some of them, and the “New State” of Getúlio Vargas in Brazil is a paradigmatic case. In this essay, we analyse the processes of institutional reform in 1930s Brazil paying particular attention to how domestic political actors look at institutional models of fascism and corporatism.info:eu-repo/semantics/publishedVersio