1,953 research outputs found

    A new LED-LED portable CO2 gas sensor based on an interchangeable membrane system for industrial applications

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    A new system for CO2 measurement (0-100%) by based on a paired emitter-detector diode arrangement as a colorimetric detection system is described. Two different configurations were tested: configuration 1 (an opposite side configuration) where a secondary inner-filter effect accounts for CO2 sensitivity. This configuration involves the absorption of the phosphorescence emitted from a CO2-insensitive luminophore by an acid-base indicator and configuration 2 wherein the membrane containing the luminophore is removed, simplifying the sensing membrane that now only contains the acid-base indicator. In addition, two different instrumental configurations have been studied, using a paired emitter-detector diode system, consisting of two LEDs wherein one is used as the light source (emitter) and the other is used in reverse bias mode as the light detector. The first configuration uses a green LED as emitter and a red LED as detector, whereas in the second case two identical red LEDs are used as emitter and detector. The system was characterised in terms of sensitivity, dynamic response, reproducibility, stability and temperature influence. We found that configuration 2 presented a better CO2 response in terms of sensitivity

    The cult of St Nicholas in medieval Italy

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    St Nicholas was one of the most popular saints in medieval Italy. His cult attracted the attention of popes, kings and emperors, and his shrine at Bari became an important international pilgrimage destination. This thesis asks how the cult of St Nicholas came to be so widespread and popular in Italy, and why the saint attracted the attention of diverse groups and individuals. This thesis is structured around four chapters. The first demonstrates that through a process of Latinisation the cult of St Nicholas became integrated within Italian literary traditions and within a new spiritual era. Chapter Two reveals that this Latinisation also occurred within the saint’s iconography. Chapters Three and Four are case studies of the cult in Puglia and Venice, locations which claimed possession of the saint’s relics. These case studies show that the general developments that the cult of St Nicholas underwent in Italy, identified in Chapters One and Two, did not apply universally. Instead, the presence of the saint’s relics resulted in a different profile of the saint in Bari and Venice. Through the process of Latinisation, the cult of St Nicholas became updated and remained relevant for its new Italian audience; Chapters Three and Four show alternative ways that the cult of St Nicholas gained widespread popularity. This thesis presents for the first time an iconographical study of St Nicholas in Italian art, which develops existing research of the saint’s Byzantine iconography. Chapter Four presents a profile of the cult of St Nicholas in Venice in the Middle Ages, which is a significant oversight in the literature. The thesis uses a variety of visual and textual sources, in particular fresco and altarpiece representations, archival documents from Venice and Rome (including the Apostolic Visitations), and under-exploited contemporary and antiquarian Venetian sources

    Dabigatran, rivaroxaban, or apixaban versus enoxaparin for thromboprophylaxis after total hip or knee replacement: systematic review, meta-analysis, and indirect treatment comparisons

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    Objective To analyse clinical outcomes with new oral anticoagulants for prophylaxis against venous thromboembolism after total hip or knee replacement

    Near Infrared Sensor to Determine Carbon Dioxide Gas Based on Ionic Liquid

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    In this study we present an NIR carbon dioxide gas sensor based on an inner filter process that includes an ionic liquid (IL), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), to improve its stability, dynamic behavior and lifetime, which are usually the main drawbacks with these sensors. The presence of CO2 causes a displacement of a simple boron-dipyrromethene-type fluorophore, azaBODIPY, as the pH indicator towards its acid form. This increases the emission intensity of Cr(III)-doped gadolinium aluminium borate (GAB) as the luminophore. The characterization of the prepared sensor was carried out and a discussion of the results is presented. The response and recovery times improved considerably, 23 and 49 s, respectively, with respect to the sensor without IL, at 60 and 120 s, respectively,. Additionally, the measurement range is extended when using IL, able in this case to measure in the complete range up to 100% CO2; without IL the measurement range is limited to 60% CO2. The detection limit ranges from 0.57% CO2 without IL to 0.26% CO2 when IL is added. The useful lifetime of the sensing membrane was 20 days for membranes with IL and only 6 days for membranes without IL, with the sensor always kept in the dark and without the need to maintain a special atmosphere

    Carbon dioxide sensors for food packaging

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    Traditional food packaging objective is the isolation of products from the outer atmosphere to extend their shelf life. In response to current necessities, traditional food packaging has led to smart packaging. CO2 inside food packages is a key factor to control. CO2 sensors can give information about the modified atmosphere integrity, indicating that the inner atmosphere is intact or if it has been broken and therefore the used by date must not be trusted, or about how fresh is the packaged product. This article briefly describes the types of packaging (traditional and smart) and how CO2 sensors can be used in the food industry. Different approaches for their integration in packaged food are described and the characteristics that must comply in order to be integrated in the agro-alimentary industry.European Union's Horizon 2020 research and innovation programme under grant agreement No 706303 (Multisens)CTQ2016–78754-C2-1-R project from the Spanish MINECO

    Evaluation of the Chagas VirCliaÂź and Chagas TESA VirCliaÂź for the Diagnosis of Trypanosoma cruzi Infection

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    Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is an important problem of public health even in regions where it is not endemic. Spain ranks second worldwide in terms of imported cases of T. cruzi infection in the chronic phase. The diagnosis in this stage is made via the detection of antibodies against T. cruzi. Therefore, we aimed to evaluate the sensitivity and specificity of two fully automated chemiluminescence immunoassays, Chagas VirCliaÂź (CHR), which uses a mixture of recombinant antigens, and Chagas TESA VirCliaÂź (TESA), the first chemiluminescence assay based on excretion-secretion antigens of trypomastigotes, both designed in monotest format. A retrospective case-control study was performed using 105 well-characterized samples: 49 from patients with CD, 22 from uninfected individuals, and 32 from patients with other pathologies. Sensitivity was 98% for CHR and 92% for TESA. In contrast, the specificity in both was 100%. Cross-reactivity was observed in leishmaniasis (2/10). CHR meets the criteria to become a tool for serological screening, while TESA has the potential for confirmation and cross-reaction discrimination. The monotest format allows its application in laboratories with a small number of samples. The high specificity of both assays is useful in areas where leishmaniasis is endemic.This research was funded by Surveillance Program of Chagas disease in Spain of CNM, Instituto de Salud Carlos III (ISCIII), Madrid, Spain, and Mundo Sano Foundation-Spain.S

    A new LED-LED portable CO2 gas sensor based on an interchangeable membrane system for industrial applications

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    CO2 monitoring is important for many areas of high economic relevance, like environmental monitoring, control of biotechnological processes in bio-pharmaceutical industries, and the food industry, particularly controlled atmosphere storage rooms and modified atmosphere packaging [ ]. CO2 sensing is not a trivial area of research, as is testified by the increasing numbers of publications regarding this topic over the past decade. The main reason is that CO2 chemically is relatively unreactive, and therefore finding a mechanism for signal generation is difficult. Most publications are based on its well-known acidic properties. In this communication, we present a portable optical sensor for gaseous CO2 detection based on the phosphorescence intensity variation of a platinum octaethylporphyrin (PtOEP) complex trapped in oxygen-insensitive poly(vinylidene chloride-co-vinyl chloride) (PVCD) membranes. The sensing mechanism arises from the increasing displacement of the α-naphtholphthalein acid–base equilibrium with rising CO2 concentrations [ ]. The low-power LED-based optical sensing instrumentation for monitoring CO2 is based on a pair of light emitting diodes (LEDs) arranged to face each other, wherein one LED functions as the light source and the other LED is reverse biased to function as a light detector [ ]. A transparent polymer substrate coated on both sides with the CO2 sensitive membrane placed between the two LEDs serves as a chemically responsive filter between the light source and the detector

    Learning Experiences of Future Healthcare Support Workers Enrolled in a Dual Mode Vocational Training Programme

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    With life expectancy increasing, there is a growing need to train healthcare support workers who provide care for dependent people in healthcare centres and at home. This qualitative study, based on Gadamer's hermeneutic philosophy, aimed to understand the learning experiences of future healthcare support workers currently enrolled in an intermediate, dual modality vocational training programme with regard to caring for dependent people. Methods: Convenience sampling was used to recruit the participants, who were all students enrolled in an intermediate level vocational training programme in care for dependent people. Fourteen in-depth interviews and one focus group session were conducted with the students. Atlas.ti 8.0 software was used to analyse the participants' accounts. Results: The students highlighted the vocational nature of their studies and the need to feel competent and useful as a healthcare support worker for dependent people. Practice-based learning and the need for training in core competences are complementary and essential elements of the training process. Conclusions:The participants' previous experiences were key in determining their academic trajectory and reflect their motivation and interest to learn. However, they feel vulnerable, unprotected, and lack training in psychosocial skills. Educational institutions should focus training programmes on the practice and development of psychosocial skills that motivate students to acquire transversal competencesThis work was funded by Ayudas a la Transferencia de investigaciĂłn de la Universidad de AlmerĂ­a UALtransfierE2022. Referencia TRFE-SI-2022/009
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