Development of highly sensitive temperature microsensors for localized measurements

This paper presents the design, fabrication and characterization of temperature microsensors based on Resistance Temperature Detectors (RTDs) with a meander-shaped geometry. Numerical simulations were performed for studying the sensitivity of the RTDs according to their windings numbers as well as for optimizing their layout. These RTDs were fabricated using well-established microfabrication and photolithographic techniques. The fabricated sensors feature high sensitivity (0.3542 mV/°C), linearity and reproducibility in a temperature range of 35 to 45 °C. Additionally, each sensor has a small size with a strong potential for their integration in microfluidic devices, as organ-on-a-chip, allowing the possibility for in-situ monitoring the physiochemical properties of the cellular microenvironment.This work is the result of the project NORTE-01-0145-FEDER-029394, RTChip4Theranostics, and was supported by Programa Operacional Regional do Norte–Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (FEDER) and by Fundação para a Ciência e Tecnologia (FCT), IP, project reference PTDC/EMD-EMD/29394/2017. The authors also acknowledge the partial financial support by the projects UIDB/04436/2020 and UIDP/04436/2020

Methodology for phytoplankton taxonomic group identification towards the development of a lab-on-a-chip

This paper presents the absorbance and fluorescence optical properties of various phytoplankton species, looking to achieve an accurate method to detect and identify a number of phytoplankton taxonomic groups. The methodology to select the excitation and detection wavelengths that results in superior identification of phytoplankton is reported. The macroscopic analyses and the implemented methodology are the base for designing a lab-on-a-chip device for a phytoplankton group identification, based on cell analysis with multi-wavelength lighting excitation, aiming for a cheap and portable platform. With such methodology in a lab-on-a-chip device, the analysis of the phytoplankton cells’ optical properties, e.g., fluorescence, diffraction, absorption and reflection, will be possible. This device will offer, in the future, a platform for continuous, autonomous and in situ underwater measurements, in opposition to the conventional methodology. A proof-of-concept device with LED light excitation at 450 nm and a detection photodiode at 680 nm was fabricated. This device was able to quantify the concentration of the phytoplankton chlorophyll a. A lock-in amplifier electronic circuit was developed and integrated in a portable and low-cost sensor, featuring continuous, autonomous and in situ underwater measurements. This device has a detection limit of 0.01 µ/L of chlorophyll a, in a range up to 300 µg/L, with a linear voltage output with chlorophyll concentration.European Regional Development Fund (ERDF) through the Interreg VA Spain-Portugal (POCTEP) 2014–2020 Program under grant agreement 0591_FOODSENS_1_E, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020, and by project NORTE-08-5369-FSE-000039 co-founded by the European Social Fund FSE and through National funds NORTE 2020 and Regional Operacional Programa of North 2014/2020. The University of Vigo work was funded by a Xunta de Galicia grant to the Biological Oceanography Research Group (Consolidación e estruturación de unidades). This output reflects only the views of the authors, and the program authorities cannot be held responsible for any use that may be made of the information contained therei

PtOEP–PDMS-based optical oxygen sensor

The advanced and widespread use of microfluidic devices, which are usually fabricated in polydimethylsiloxane (PDMS), requires the integration of many sensors, always compatible with microfluidic fabrication processes. Moreover, current limitations of the existing optical and electrochemical oxygen sensors regarding long-term stability due to sensor degradation, biofouling, fabrication processes and cost have led to the development of new approaches. Thus, this manuscript reports the development, fabrication and characterization of a low-cost and highly sensitive dissolved oxygen optical sensor based on a membrane of PDMS doped with platinum octaethylporphyrin (PtOEP) film, fabricated using standard microfluidic materials and processes. The excellent mechanical and chemical properties (high permeability to oxygen, anti-biofouling characteristics) of PDMS result in membranes with superior sensitivity compared with other matrix materials. The wide use of PtOEP in sensing applications, due to its advantage of being easily synthesized using microtechnologies, its strong phosphorescence at room temperature with a quantum yield close to 50%, its excellent Strokes Shift as well as its relatively long lifetime (75 µs), provide the suitable conditions for the development of a miniaturized luminescence optical oxygen sensor allowing long-term applications. The influence of the PDMS film thickness (0.1–2.5 mm) and the PtOEP concentration (363, 545, 727 ppm) in luminescent properties are presented. This enables to achieve low detection levels in a gas media range from 0.5% up to 20%, and in liquid media from 0.5 mg/L up to 3.3 mg/L at 1 atm, 25 °C. As a result, we propose a simple and cost-effective system based on a LED membrane photodiode system to detect low oxygen concentrations for in situ applications.This work was co-financed by national funds through FCT—Fundação para a Ciência e Tecnologia, I.P. under project SONDA (PTDC/EME-SIS/1960/2020), by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER), Project NORTE-01-0145-FEDER-000032—NextSea, by the European Regional Development Fund (ERDF) through INTERREG V-A Spain-Portugal Programme (POCTEP) 2014–2020, Project N. 0591_FOODSENS_1_E and by FCT national funds, under the national support to R&D units grants, through the reference projects UIDB/04436/2020 and UIDP/04436/2020

Arbustus unedo essence: morphological and genetic characterization of the strawberry tree of Castelo de Paiva

O medronheiro é um arbusto da região mediterrânica que pode ser encontrada por todo o país. Ao contrário do que verifica na região sul do país, no concelho de Castelo de Paiva é atribuída uma reduzida importância económica a esta espécie. Com o intuito de preservar e potenciar a produção desta espécie e contribuir para a dinamização da economia do concelho, procedeu-se à caracterização morfológica e genética de uma amostra da população de medronheiros de Castelo de Paiva. A caracterização morfológica e genética foi realizada para um total de 10 genótipos. Para tal recolheram-se 70 folhas aleatoriamente em cada árvore. Em 40 folhas mediu-se o comprimento, largura, comprimento do pedúnculo, peso fresco, peso seco e determinou-se a área foliar. Dos caracteres morfológicos analisados, aqueles que se revelaram mais úteis na distinção dos vários genótipos foram: comprimento do pedúnculo, peso fresco e peso seco. As restantes 30 folhas foram utilizadas para a caracterização genética. Esta caracterização foi realizada recorrendo a um marcador de DNA, ISSR. Os 5 primeiros exemplaresutilizados na técnica de ISSR demonstraram-se polimórficos. Os resultados da caracterização genética sugerem que a variabilidade genética na população é média a alta.The strawberry tree is a shrub native in the Mediterranean region and it can be found throughout Portugal. Unlike the case in the southern region of the country, in Castelo de Paiva a minor economic importance is given to this species. In order to preserve, to enhance the production of this species and to contribute to the boosting of the economy of the region, we proceeded to the characterization of a small sample population of this fruit tree of Castelo de Paiva in what concerns to its morphology and genetics. The morphological and genetic characterization was performed for a total of 10 genotypes. For this, 70 leaves were randomly collected from each tree. For 40 leaves, it was measured the length, the width, the peduncle length, the wet weight, the dry weight and determined the leaf area. Of the morphological characteristics analyzed, the ones that proved most useful in distinguishing the various genotypes were: the length peduncle, the wet weight and the dry weight. The remaining 30 leaves were used in the genetic characterization. This characterization was performed using a DNA marker, the ISSR. The 5 primers used in the ISSR technique proved to be polymorphic. The results from the genetic characterization suggest that variability in population genetics is medium to high

MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal

Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications

Imunossensor microfluídico para quantificação de cortisol salivar

Tese de Doutoramento em Engenharia BiomédicaO stress físico e psicológico resultante do estilo de vida da sociedade atual é responsável pelo aparecimento de diversas doenças tais como depressão, ansiedade, enfarte do miocárdio, entre outras. A exposição prolongada ao stress ativa uma série de processos fisiológicos com consequente alteração dos níveis de alguns biomarcadores, especialmente da hormona de cortisol que tem sido descrita como um dos principais biomarcadores para a monitorização de stress. Os níveis desta hormona são caracterizados por um ciclo circadiano com um nível máximo pela manhã e uma diminuição ao longo do dia. Este ciclo circadiano do cortisol apresenta um papel crucial na regulação de vários processos fisiológicos e, por isso, é de extrema importância monitorizar a concentração de cortisol no corpo humano, principalmente ao longo do dia, para verificar se as variações dos níveis de cortisol advêm, por exemplo, do stress crónico. Além disso, muitos estadios patológicos resultam de perturbações dos níveis de cortisol inerentes ao mau funcionamento das glândulas, como o síndrome de Cushing e doença de Addison. Desta forma, torna-se importante desenvolver ferramentas de monitorização do cortisol capazes de realizar análises rápidas ao longo do seu ciclo circadiano. O presente trabalho apresenta o desenvolvimento de um novo imunossensor microfluídico fabricado em poli(dimetilsiloxano) (PDMS) que integra sistemas de deteção ótica fabricados em CMOS (complementary metal oxide semiconductor) para a quantificação rápida e extremamente sensível de cortisol salivar. O método de recolha simples e não invasivo de amostras de saliva fornece uma alternativa interessante ao sangue, permitindo amostragens em curtos intervalos de tempo, o que é um requisito na avaliação dos níveis de cortisol ao longo do dia, sendo de igual modo relevante para muitas outras aplicações de diagnóstico clínico. A abordagem desenvolvida baseia-se num imunoensaio competitivo, no qual são imobilizados covalentemente anticorpos (Ac) de revestimento (anti-IgG policlonais) sobre a superfície do PDMS previamente funcionalizada com grupos amina. Os Ac de revestimento ligam-se à região Fc (fração constante) dos Ac específicos para o cortisol (Ac de captura) permitindo a sua correta orientação. O cortisol marcado com a enzima HRP (horseradish peroxidase) é utilizado para a quantificação, inversamente proporcional, do cortisol da amostra. Os locais de ligação aos Ac de captura vão sendo ocupados pela competição do cortisol da amostra com o cortisol marcado com HRP. Este último, ligado ao Ac de captura, é medido através da reação entre a enzima HRP e o substrato colorimétrico TMB (3,3’,5,5’-tetramethylbenzidine) por absorção ótica a 450 nm, utilizando como fotodetetor um fotodíodo CMOS integrado on-chip. Com as condições otimizadas apresentadas neste trabalho, isto é, a geometria dos canais microfluídicos, os métodos de imobilização e as condições do imunoensaio, o imunossensor desenvolvido apresenta um consumo de reagentes entre 5-20 μL, uma gama linear de deteção entre 0,01-20 ng/mL com um limite de deteção de 18 pg/mL e um tempo de análise de 35 min. Assim, o imunossensor desenvolvido fornece uma alternativa vantajosa quando comparado com os métodos bem estabelecidos de análises clínicas (designados de gold-standard) apresentando grande potencial para aplicações point-of-care (POC) que requerem monitorização contínua dos níveis de cortisol salivar.The physical and psychological stress resulting from the current society's lifestyle is responsible for the appearance of several diseases, such as depression, anxiety, myocardial infarction, among others. Prolonged exposure to stress actives several physiological effects with consequent change in some biomarkers levels, especially cortisol hormone, that has been described as one of the main biomarkers for stress monitoring. Cortisol hormone levels are characterized by a circadian cycle with a morning maximum and a decrease throughout the day. This circadian cycle of cortisol plays a crucial role in various physiological processes regulation and, therefore, it is extremely important to monitor the cortisol concentration in the human body, mainly throughout the day, in order to verify if the changes that can occur in cortisol levels are a result, for example, of a chromic stress. In addition, many pathological stages result from disorders of cortisol levels inherent to the glands malfunctioning such as Cushing's syndrome and Addison's disease. Thus, it is important to develop cortisol monitoring tools capable of performing rapid analyses throughout the circadian cycle. This work presents a novel poly(dimethylsiloxane) (PDMS) microfluidic immunosensor that integrates a complementary metal oxide semiconductor (CMOS) optical detection system for a rapid and highly-sensitive quantification of salivary cortisol. The simple and non-invasive method of saliva sampling provides an interesting alternative to the blood, allowing a fast sampling at short intervals, advantageous for many clinical diagnostic applications. The developed approach is based on competitive immunoassay, where coating antibodies (anti-IgG polyclonal) are immobilized on the PDMS surface, previously functionalized with amine groups. Coating antibodies binds the Fc (constant fraction) region of the capture antibodies allowing their correct orientation. Horseradish peroxidase (HRP)- labelled cortisol is used to perform the inversely proportional quantification of the sample cortisol. The capture Ab binding sites are occupied by competition between the cortisol of the sample and the HRP-labelled cortisol. The latter, bound to the capture antibodies, is measured, after the reaction between HRP enzyme and the TMB (3,3’,5,5’- tetramethylbenzidine) that produces a colorimetric substrate, through optical absorption at 450 nm, using a CMOS silicon photodiode as the photodetector. Under the developed optimized conditions presented here, e.g., microfluidic channels geometry, immobilization method and immunoassay conditions, the immunosensor shows a reagent consumption between 5-20 μL, a linear range of detection between 0.01-20 ng/mL, a limit of detection of 18 pg/mL and an analysis time of 35 min. So, the developed immunosensor provides an advantageous alternative when compared to the well-established methods of clinical analyses (gold standard) featuring a great potential for point-of-care (POC) applications requiring continuous monitoring of the salivary cortisol levels

PDMS biofunctionalization study for the development of a microfluidic device: Application to salivary cortisol

The authors acknowledge to Sofia Neves from ICVS for her help in the antibodies selection.This paper presents the study of the PDMS (poly(dimethylsiloxane)) surface functionalization for the development of a microfluidic immunosensor that quantitatively analyss salivary cortisol by optical detection. The functionalization was performed using different antibodies immobilization methods on PDMS surface: (a) immobilization by passive adsorption on pristine PDMS; (b) silanization of PDMS surface with (3-aminopropyl)-triethoxysilane (APTES) to generate amino groups and posterior covalent immobilization of antibodies on APTES-PDMS using cross-linker glutaraldehyde (GA); (c) coating the PDMS surface with BSA to block non-specific protein adsorption, and then covalent bond of the protein A via GA. In this last approach, the antibodies were covalently immobilized to protein A due to its high affinity with the constant fraction (Fc) region of the antibodies. Atomic force microscope (AFM) and spectrophotometric analysis demonstrated that the immobilization method using protein A is more efficient since a higher roughness and uniformity on the PDMS surface and higher absorbance signals were obtainedThis work is funded by FEDER funds through the "Eixo I do Programa Operacional Fatores de Competitividade (POFC) QREN, project references COMPETE: FCOMP-01-0124FEDER-020241 and by FCT – Fundação para a Ciência e a Tecnologia, project reference PTDC/EBB-EBI/120334/2010. V. C. Pinto thanks the FCT for the SFRH/BD/81526/2011 PhD grant. The authors acknowledge to Sofia Neves from ICVS for her help in the antibodies selection

Special issue on novel technology and applications of micro/nano devices and system

[Excerpt] The development of novel technologies and applications for micro/nano devices is an interdisciplinary subject that demands an integration of several research fields, such as material science, biotechnology, medicine, chemistry, informatics, optics, electronics, mechanics, and micro/nanotechnologies. In this regard, this Special Issue on “Novel Technology and Applications of Micro/Nano Devices and Systems” seeks to gather the ultimate breakthroughs and innovative development techniques used in this multidisciplinary area, aiming toward an end-use of this technology