The easy and rapid spread of bacterial contamination and the risk it poses to human health makes evident the need for analytical methods alternative to conventional time-consuming laboratory-based techniques for bacterial detection. To tackle this demand, biosensors based on isothermal DNA amplification methods have emerged, which avoid the need for thermal cycling, thus facilitating their integration into small and low-cost devices for in situ monitoring. This review focuses on the breakthroughs made on biosensors based on isothermal amplification methods for the detection of bacteria in the field of food safety and environmental monitoring. Optical and electrochemical biosensors based on loop mediated isothermal amplification (LAMP), rolling circle amplification (RCA), recombinase polymerase amplification (RPA), helicase dependent amplification (HDA), strand displacement amplification (SDA), and isothermal strand displacement polymerisation (ISDPR) are described, and an overview of their current advantages and limitations is provided. Although further efforts are required to harness the potential of these emerging analytical techniques, the coalescence of the different isothermal amplification techniques with the wide variety of biosensing detection strategies provides multiple possibilities for the efficient detection of bacteria far beyond the laboratory bench.

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Two small Lagocephalus sceleratus juveniles were captured in picarel targeting catches from North Aegean Sea (Greece) in the autumn of 2017. An electrochemical immunosensing tool using magnetic beads as immobilisation support was developed and applied to the rapid 2 screening of tetrodotoxins (TTXs), potent neurotoxins that constitute a food safety hazard when present in seafood. This tool revealed the presence of TTXs in both individuals. Results were compared with those provided by mELISA and LC-HRMS, the latter confirming the presence of TTX. Some of the tissues contained TTX contents close to or above 2 mg/kg. L. sceleratus juveniles had been considered as non-toxic and, to our knowledge, this is the first report of high TTX levels in small L. sceleratus individuals. Such specimens can be mistaken with other edible species, posing a threat to consumers. The availability of low-cost and user-friendly tools for TTXs detection will contribute to guarantee seafood safety.

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ResumoA literatura acadêmica apresenta conceitos que são explorados pelo seu aspecto formal e informal. Também enfatiza que os relacionamentos interpessoais informais complementam e contribuem de forma sinérgica com os relacionamentos formais que ocorrem nas diversas atividades humanas. Alguns autores estudaram a similaridade entre as partes formal e informal, outros indicaram que se poderia estudar os efeitos conjuntos da interação ou o delineamento dos limites da parte informal pela parte formal ou se ambas apresentariam influências recíprocas. Neste trabalho são comparadas as redes sociais formais e informais de duas turmas distintas de alunos universitários e em momentos diferentes para verificar a existência da interação entre os elementos formais e informais dessas redes. Foi realizado um estudo de campo de caráter exploratório com auxílio da análise de redes sociais por meio do software Ucinet 6.0 e Netdraw. Foram coletadas várias medidas com base na percepção dos alunos e a análise dos dados indicou resultados não condizentes com a literatura, indicando a não ocorrência de relação entre os aspectos formal e informal. Dada a importância dessa interação, cabe aos professores e à instituição de ensino prover meios para que isso ocorra. Os resultados indicam a necessidade de mais estudos científicos a respeito do tema.Palavras-chave: análise de redes sociais; redes formais; redes informais; estudante universitário. AbstractThe academic literature presents concepts that are explored by their formal and informal aspects. In addition, it is emphasized that informal interpersonal relationships complement and contribute synergistically with the formal relationships that occur in the various human activities. Some authors have studied the similarity between the formal and informal parts, others have indicated that one could study the joint effects of interaction or the delineation of the boundaries of the informal part by the formal part or if both would have reciprocal influences. In this work we compare the formal and informal social networks of two distinct groups of university students and at different moments to verify the existence of the interaction between the formal and informal elements of these networks. An exploratory field study was carried out with the help of social networks analysis through the software Ucinet 6.0 and Netdraw. Several measures were collected based on the students' perception and the analysis of the data indicated results that were not consistent with the literature, indicating the non-occurrence of a relationship between the formal and informal aspects. Given the importance of this interaction, it is up to the teachers and the educational institution to provide the means for this to occur. The results indicate the need for more scientific studies on the subject.