Passive direct methanol fuel cells acting as fully autonomous electrochemical biosensors: Application to sarcosine detection

This work describes an innovative electrochemical biosensor that advances its autonomy toward an equipment-free design. The biosensor is powered by a passive direct methanol fuel cell (DMFC) and signals the response via an electrochromic display. Briefly, the anode side of the DMFC power source was modified with a biosensor layer developed using molecularly imprinted polymer (MIP) technology to detect sarcosine (an amino acid derivative that is a potential cancer biomarker). The biosensor layer was anchored on the surface of the anode carbon electrode (carbon black with Pt/Ru, 40:20). This was done by bulk radical polymerization with acrylamide, bis-acrylamide, and vinyl phosphonic acid. This layer selectively interacted with sarcosine when integrated into the passive DMFC (single or multiple, in a stack of 4), which acted as a transducer element in a concentration-dependent process. Serial assembly of a stack of hybrid DMFC/biosensor devices triggered an external electrochromic cell (EC) that produced a colour change. Calibrations showed a concentration-dependent sarcosine response from 3.2 to 2000 µM, which is compatible with the concentration of sarcosine in the blood of prostate cancer patients. The final DMFC/biosensor-EC platform showed a colour change perceptible to the naked eye in the presence of increasing sarcosine concentrations. This colour change was controlled by the DMFC operation, making this approach a self-controlled and self-signalling device. Overall, this approach is a proof-of-concept for a fully autonomous biosensor powered by a chemical fuel. This simple and low-cost approach offers the potential to be deployed anywhere and is particularly suitable for point-of-care (POC) analysis.The authors acknowledge the financial support of EU-Horizon 2020 (Symbiotic, FET-Open, GA665046), and from national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, UIDB/50025/2020 and UID/EMS/00532/2019. Nádia Ferreira (SFRH/BD/122955/2016), Liliana Carneiro (SFRH/BD/122954/2016), and Ana Carolina Marques (SFRH/BD/115173/2016) acknowledge Fundação para a Ciência e Tecnologia (FCT) for financial support.info:eu-repo/semantics/publishedVersio

Identification of a bitter-taste receptor gene repertoire in different Lagomorphs species

The repertoires of bitter-taste receptor (T2R) gene have been described for several animal species, but these data are still scarce for Lagomorphs. The aim of the present work is to identify potential repertoires of T2R in several Lagomorph species, covering a wide geographical distribution. We studied these genes in Lepus timidus, L. europaeus, Oryctolagus cuniculus algirus, Romerolagus diazi, and Sylvilagus floridanus, using O. cuniculus cuniculus as control species for PCR and DNA sequencing. We studied the identities of the DNA sequences and built the corresponding phylogenetic tree. Sequencing was successful for both subspecies of O. cuniculus for all T2R genes studied, for five genes in Lepus, and for three genes in R. diazi and S. floridanus. We describe for the first time the partial repertoires of T2R genes for Lagomorphs species, other than the common rabbit. Our phylogenetic analyses indicate that sequence proximity levels follow the established taxonomic classification

The exhibition Plasticity – A History of Plastics in Portugal: A participative process at the Leiria Museum

PTDC/IVC-HFC/5174/2014As part of the project “O Triunfo da Baquelite – Contributos para uma História dos Plásticos em Portugal” (2016-2019), the exhibition Plasticidade – Uma História dos Plásticos em Portugal (2019-2021) was organized on the history of plastic materials, in partnership with the Leiria Museum. The exhibition highlighted the importance of plastics, its relationship with the history of industry, design, consumption and mentalities, and science and technology in Portugal, through a process of musealization. In this article we reflect on the exhibition, its objectives and approaches, and on the formation of a collection of plastics, through a participatory process with the communities. In addition, the novelty in considering these materials as “museum objects” led to the analysis of its conservation and restoration issues. The article emphasises the relevance of this project, whether from the point of view of research, or the contribution to the musealization of these types of objects and its preservation. With the creation of a collection and an exhibition at the Leiria Museum, we contributed to fill the gap with a collection dedicated to plastics, reflecting a history of plastics in its multiple aspects of usability in society.publishersversionpublishe

Sequence analysis of bitter taste receptor gene repertoires in different ruminant species

Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy

Label-Free Nanosensing Platform for Breast Cancer Exosome Profiling

Breast cancer accounts for 11.6% of all cancer cases in both genders. Even though several diagnostic techniques have been developed, the mostly used are invasive, complex, time-consuming, and cannot guarantee an early diagnosis, significantly constraining the tumor treatment success rate. Exosomes are extracellular vesicles that carry biomolecules from tissues to the peripheral circulation, representing an emerging noninvasive source of markers for early cancer diagnosis. Current techniques for exosomes analysis are frequently complex, time-consuming, and expensive. Raman spectroscopy interest has risen lately, because of its nondestructive analysis and little to no sample preparation, while having very low analyte concentration/volume, because of surface enhancement signal (SERS) possibility. However, active SERS substrates are needed, and commercially available substrates come with a high cost and low shelf life. In this work, composites of commercial nata de coco to produce bacterial nanocellulose and in-situ-synthesized silver nanoparticles are tested as SERS substrates, with a low cost and green approach. Enhancement factors from 104 to 105 were obtained, detecting Rhodamine 6G (R6G) concentrations as low as 10−11 M. Exosome samples coming from MCF-10A (nontumorigenic breast epithelium) and MDA-MB-231 (breast cancer) cell cultures were tested on the synthesized substrates, and the obtained Raman spectra were subjected to statistical principal component analysis (PCA). Combining PCA with Raman intravariability and intervariability in exosomal samples, data grouping with 95% confidence was possible, serving as a low-cost, green, and label-free diagnosis method, with promising applicability in clinical settings

Direitos Autorais e Propriedade Intelectual na Era da Informação

Porto AlegreA coletânea é resultado de pesquisas de estudantes e professores do Programa de Pós-graduação em Ciência da Informação da Universidade Federal da Bahia. Apresenta um panorama sobre propriedade intelectual e suas ramificações, com ênfase nas questões de plágio e direitos autorais à luz da Ciência da Informação. Discute a produção artístico-cultural e o uso de conteúdos disseminados em plataformas digitais, evidenciando questões inerentes à multiplicação de dados e seu compartilhamento em multimeios. Sob a perspectiva da Ciência Aberta, a obra visa trazer novos olhares sobre os interesses que perpassam os direitos do autor, visando o interesse coletivo de difusão de saberes