Immobilization of streptavidin on a plasmonic Au-TiO2 thin film towards an LSPR biosensing platform

Optical biosensors based on localized surface plasmon resonance (LSPR) are the future of label-free detection methods. This work reports the development of plasmonic thin films, containing Au nanoparticles dispersed in a TiO2 matrix, as platforms for LSPR biosensors. Post-deposition treatments were employed, namely annealing at 400 °C, to develop an LSPR band, and Ar plasma, to improve the sensitivity of the Au-TiO2 thin film. Streptavidin and biotin conjugated with horseradish peroxidase (HRP) were chosen as the model receptor–analyte, to prove the efficiency of the immobilization method and to demonstrate the potential of the LSPR-based biosensor. The Au-TiO2 thin films were activated with O2 plasma, to promote the streptavidin immobilization as a biorecognition element, by increasing the surface hydrophilicity (contact angle drop to 7°). The interaction between biotin and the immobilized streptavidin was confirmed by the detection of HRP activity (average absorbance 1.9 ± 0.6), following a protocol based on enzyme-linked immunosorbent assay (ELISA). Furthermore, an LSPR wavelength shift was detectable (0.8 ± 0.1 nm), resulting from a plasmonic thin-film platform with a refractive index sensitivity estimated to be 33 nm/RIU. The detection of the analyte using these two different methods proves that the functionalization protocol was successful and the Au-TiO2 thin films have the potential to be used as an LSPR platform for label-free biosensors.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020, UIDB/04050/2020, and UID/EMS/00285/2020, and by the projects NANO4BIO: POCI-01-0145-FEDER-032299, with FCT reference PTDC/FIS-MAC/32299/2017, and CO2Plasmon, with FCT reference EXPL/CTM-REF/0750/2021. Patrícia Pereira-Silva, Diana I. Meira, and Diogo Costa acknowledge FCT for their Ph.D. scholarships, 2020.08235.BD, SFRH/BD/143262/2019, and SFRH/BD/136279/2018, respectively. Augusto Costa-Barbosa also acknowledges FCT for his Ph.D. scholarships SFRH/BD/133513/2017 and COVID/BD/152169/2021. The authors would like to express their gratitude to Nuno P. Barradas (C2TN, University of Lisbon) and Eduardo Alves (IPFN, University of Lisbon) for RBS measurements and analysis

Optimization of Au:CuO thin films by plasma surface modification for high-resolution LSPR gas sensing at room temperature

In this study, thin films composed of gold nanoparticles embedded in a copper oxide matrix (Au:CuO), manifesting Localized Surface Plasmon Resonance (LSPR) behavior, were produced by reactive DC magnetron sputtering and post-deposition in-air annealing. The effect of low-power Ar plasma etching on the surface properties of the plasmonic thin films was studied, envisaging its optimization as gas sensors. Thus, this work pretends to attain the maximum sensing response of the thin film system and to demonstrate its potential as a gas sensor. The results show that as Ar plasma treatment time increases, the host CuO matrix is etched while Au nanoparticles are uncovered, which leads to an enhancement of the sensitivity until a certain limit. Above such a time limit for plasma treatment, the CuO bonds are broken, and oxygen is removed from the film’s surface, resulting in a decrease in the gas sensing capabilities. Hence, the importance of the host matrix for the design of the LSPR sensor is also demonstrated. CuO not only provides stability and protection to the Au NPs but also promotes interactions between the thin film’s surface and the tested gases, thereby improving the nanocomposite film’s sensitivity. The optimized sensor sensitivity was estimated at 849 nm/RIU, which demonstrates that the Au-CuO thin films have the potential to be used as an LSPR platform for gas sensors.This research was sponsored by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020 and by the project CO2Plasmon with reference EXPL/CTM-REF/0750/2021. M.P. acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/137076/2018. Diana I. Meira acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/143262/2019

Compreender a Sintomatologia Depressiva após a Cirurgia Bariátrica: o Papel do Peso, da Alimentação e da Imagem Corporal

INTRODUCTION: Depressive symptoms have been reported as prevalent after bariatric surgery. This study aims to analyze the role of weight, eating behaviors and body image in depressive symptomatology in bariatric surgery patients assessed post-operatively. MATERIAL AND METHODS: This is a cross-sectional study including 52 bariatric surgery patients assessed post-operatively with a follow-up time ranging from 22 to 132 months. Psychological assessment included a clinical interview (Eating Disorder Examination) to assess eating disorders psychopathology, and three self-report measures: Outcome Questionnaire 45--general distress; Beck Depression Inventory--depressive symptoms; and Body Shape Questionnaire--body image. RESULTS: Our data show that depressive symptoms after surgery are associated with loss of control over eating, increased concerns with body image, and body mass index regain. Multiple linear regressions was tested including these variables and showed that body mass index regain after surgery, loss of control over eating and concerns with body image significantly explained 50% of the variance of post-operative depressive symptoms, being the concern with body image the most significant variable: greater dissatisfaction with body image was associated with more depressive symptoms. DISCUSSION: The results of this study showed that a subgroup of patients presents a significant weight gain after bariatric surgery, which is associated with episodes of loss of control over eating, concerns with body image and depressive symptoms. CONCLUSION: These results stress the relevance of body image concerns after surgery and the importance of clinically addressing these issues to optimize psychological functioning after bariatric surgery

Understanding depressive symptoms after bariatric surgery: the role of weight, eating and body image

INTRODUCTION: Depressive symptoms have been reported as prevalent after bariatric surgery. This study aims to analyze the role of weight, eating behaviors and body image in depressive symptomatology in bariatric surgery patients assessed post-operatively. MATERIAL AND METHODS: This is a cross-sectional study including 52 bariatric surgery patients assessed post-operatively with a follow-up time ranging from 22 to 132 months. Psychological assessment included a clinical interview (Eating Disorder Examination) to assess eating disorders psychopathology, and three self-report measures: Outcome Questionnaire 45 - general distress; Beck Depression Inventory - depressive symptoms; and Body Shape Questionnaire - body image. RESULTS: Our data show that depressive symptoms after surgery are associated with loss of control over eating, increased concerns with body image, and body mass index regain. Multiple linear regressions was tested including these variables and showed that body mass index regain after surgery, loss of control over eating and concerns with body image significantly explained 50% of the variance of post-operative depressive symptoms, being the concern with body image the most significant variable: greater dissatisfaction with body image was associated with more depressive symptoms. DISCUSSION: The results of this study showed that a subgroup of patients presents a significant weight gain after bariatric surgery, which is associated with episodes of loss of control over eating, concerns with body image and depressive symptoms. CONCLUSION: These results stress the relevance of body image concerns after surgery and the importance of clinically addressing these issues to optimize psychological functioning after bariatric surgery

Guided play: From instruction to creativity when constructing automata

Play is a very important activity for children development and there are evidences that it can be an added value when used for educational purposes. Research about how to integrate play in education points to the importance of teacher role, namely how children play can be scaffold and guided. However, there is also lack of agreement about how to guide children playing and the impact of the guidance in the activity development and competences promoted. Given the characteristics of automata, especially the fact that they include a narrative and a mechanism, they can be used within a play based pedagogy, to implement activities related to plan and construct toys and to promote competences as observation, problem solving, creativity in the STEM areas. To explore this potential of moving toys to promote STEM in the early years of schooling is the aim of the Erasmus + AutoSTEM project. This work aims to describe the main objectives and resources of the AutoSTEM project, including the description of a workshop to construct a toy with a sliding mechanism, the Jelly Bird. The procedures involved the presentation and observation of the toy, detailed instructions on how to construct it, the decoration and the elaboration of a narrative about it. 23 children from the 2nd year of basic education participated in the workshop. The analysis of the prototypes shows that all the participants built them properly. Also some alternative ideas to the proposal initially presented emerged, as well as a diversity of narratives. These data suggest that the instructions enhanced the construction of the prototype, but did not inhibit the creativity of the work developed.publishedVersio

Outros equipamentos e métodos.

Neste capítulo são apresentados resultados do desenvolvimento de outros equipamentos e métodos não-convencionais realizados pela EMBRAPA-CNPDIA e demais instituições colaboradoras, para atender às demandas julgadas importantes para o avanço da pesquisa agropecuária. Cada equipamento ou método mostrado consta de uma introdução ao assunto, a abordagem do problema, uma breve descrição de como o equipamento ou método contribuiu para a solução, incluindo resultados e recomendações. O texto é ilustrado por figuras, diagramas e fotos, evitando-se o aprofundamento detalhado do tema, o que pode ser obtido pelas referências mencionadas para cada tópico tratado. Esta colocação mais abrangente tem por objetivo mostrar o potencial que os instrumentos aqui apresentados dispõem para enfocar e resolver problemas com o uso de equipamentos e métodos não-convencionais

The mammals of Angola

Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio