1,805 research outputs found

    Design of Molecularly Imprinted Polymers Using Supercritical Carbon Dioxide Technology

    Get PDF
    Funding Information: This research was funded from Fundação para a Ciência e a Tecnologia (FCT/MCTES, Portugal) through the projects PTDC/EQU–EQU/32473/2017, PTDC/MEC–ONC/29327/2017 and PTDC/QUI–QIN/30649/2017 (REALM); and by national funds LAQV–REQUIMTE: UIDB/50006/2020, UIDP/50006/2020, and UID/QUI/50006/2020, and co–financed by the ERDF under the PT2020 Partnership Agreement number POCI–01–0145–FEDER−007265. PhD grant (SFRH/BD/150696/2020) in the aim of the International Year of the Periodic Table—A protocol established between the Portuguese Chemical Society (SPQ) and FCT/MCTES is financed the PhD of A.I.F. Individual Scientific Employment Stimulus (CEEC–IND, reference 2020.00377.CEECIND) from the FCT/MCTES is financed the research work of R.V. The Associate Laboratory Research Unit for Green Chemistry−Clean Technologies and Processes−LAQV–REQUIMTE is financed by national funds from FCT/MCTES (UIDB/50006/2020, UIDP/50006/2020, and UID/QUI/50006/2020) and co–financed by the ERDF under the PT2020 Partnership Agreement (POCI–01–0145–FEDER−007265). Publisher Copyright: © 2024 by the authors.The design and development of affinity polymeric materials through the use of green technology, such as supercritical carbon dioxide (scCO2), is a rapidly evolving field of research with vast applications across diverse areas, including analytical chemistry, pharmaceuticals, biomedicine, energy, food, and environmental remediation. These affinity polymeric materials are specifically engineered to interact with target molecules, demonstrating high affinity and selectivity. The unique properties of scCO2, which present both liquid– and gas–like properties and an accessible critical point, offer an environmentally–friendly and highly efficient technology for the synthesis and processing of polymers. The design and the synthesis of affinity polymeric materials in scCO2 involve several strategies. Commonly, the incorporation of functional groups or ligands into the polymer matrix allows for selective interactions with target compounds. The choice of monomer type, ligands, and synthesis conditions are key parameters of material performance in terms of both affinity and selectivity. In addition, molecular imprinting allied with co–polymerization and surface modification are commonly used in these strategies, enhancing the materials’ performance and versatility. This review aims to provide an overview of the key strategies and recent advancements in the design of affinity polymeric materials using scCO2.publishersversionpublishe

    Design, Green Synthesis and Performance of L-Leucine-Molecularly Imprinted Polymers

    Get PDF
    The authors would like to acknowledge financial support from Fundação para a Ciência e a Tecnologia, Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES), Portugal, through projects PTDC/EQU-EQU/32473/2017, PTDC/MEC-ONC/29327/2017, and PTDC/QUI-QIN/30649/2017 (REALM). A.I.F. acknowledges her PhD grant (SFRH/BD/150696/2020) in the aim of the International Year of the Periodic Table─a protocol established between the Portuguese Chemical Society (SPQ) and the Portuguese Foundation for Science and Technology (FCT/MCTES). R.V. would like to acknowledge Individual Scientific Employment Stimulus (CEEC-IND), reference 2020.00377.CEECIND from the FCT/MCTES, Portugal. The Associate Laboratory Research Unit for Green Chemistry–Clean Technologies and Processes–LAQV-REQUIMTE is financed by national funds from FCT/MCTES (UIDB/50006/2020, UIDP/50006/2020, and UID/QUI/50006/2020) and cofinanced by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER–007265).Biopurification is a challenging and growing market. Despite great efforts in the past years, current purification strategies still lack specificity, efficiency, and cost-effectiveness. The development of more sustainable functional materials and processes needs to address pressing environmental goals, efficiency, scale-up, and cost. Herein, l-leucine (LEU)-molecularly imprinted polymers (MIPs), LEU-MIPs, are presented as novel biomolecular fishing polymers for affinity sustainable biopurification. Rational design was performed using quantum mechanics calculations and molecular modeling for selecting the most appropriate monomers. LEU-MIPs were synthesized for the first time by two different green approaches, supercritical carbon dioxide (scCO2) technology and mechanochemistry. A significant imprinting factor of 12 and a binding capacity of 27 mg LEU/g polymer were obtained for the LEU-MIP synthesized in scCO2 using 2-vinylpyridine as a functional monomer, while the LEU-MIP using acrylamide as a functional monomer synthesized by mechanochemistry showed an imprinting factor of 1.4 and a binding capacity of 18 mg LEU/g polymer, both systems operating at a low binding concentration (0.5 mg LEU/mL) under physiological conditions. As expected, at a higher concentration (1.5 mg LEU/mL), the binding capacity was considerably increased. Both green technologies show high potential in obtaining ready-to-use, stable, and low-cost polymers with a molecular recognition ability for target biomolecules, being promising materials for biopurification processes.publishersversionpublishe

    Severity of post-cardiac surgery acute kidney injury and long-term mortality: is chronic kidney disease the missing link?

    Get PDF
    While the retrospective cohort study by Lopez-Delgado and colleagues suggests a strong association of the RIFLE classification and long-term mortality of acute kidney injury (AKI) after post-cardiac surgery, it has a number of limitations. The numbers of patients with pre-existing chronic kidney disease (CKD) or with non-recovery of renal function, de novo CKD or progression of CKD to stage V are not given. The authors used an obsolete definition of CKD and a modified RIFLE classification system for definition and grading of AKI. Taken together, numerous studies underscore the strong association between AKI and de novo CKD. Severity, duration and frequency of AKI as well as age, comorbidities and pre-existing CKD are known risk factors for the development and/or progression of CKD. Careful analyses of the cumulative mortality curves reported by Lopez-Delgado and colleagues or by our group revealed a triphasic pattern. In the early phase, survival rates drop steeply due to critical illness, followed by a phase of smaller decline (caused by patient characteristics and development of CKD) and later on by a flatter survival curve attributable to the high cardiovascular mortality of progressive CKD. Physicians need to consider the long-term sequels of severe AKI. Lopez Delgado and colleagues's study provides further arguments for an early follow-up of survivors of AKI by nephrologists

    Impact of non-neurological complications in severe traumatic brain injury outcome

    Full text link
    Introduction: Non-neurological complications in patients with severe traumatic brain injury (TBI) are frequent, worsening the prognosis, but the pathophysiology of systemic complications after TBI is unclear. The purpose of this study was to analyze non-neurological complications in patients with severe TBI admitted to the ICU, the impact of these complications on mortality, and their possible correlation with TBI severity. Methods: An observational retrospective cohort study was conducted in one multidisciplinary ICU of a university hospital (35 beds); 224 consecutive adult patients with severe TBI (initial Glasgow Coma Scale (GCS) < 9) admitted to the ICU were included. Neurological and non-neurological variables were recorded. Results: Sepsis occurred in 75% of patients, respiratory infections in 68%, hypotension in 44%, severe respiratory failure (arterial oxygen pressure/oxygen inspired fraction ratio (PaO2/FiO(2)) < 200) in 41% and acute kidney injury (AKI) in 8%. The multivariate analysis showed that Glasgow Outcome Score (GOS) at one year was independently associated with age, initial GCS 3 to 5, worst Traumatic Coma Data Bank (TCDB) first computed tomography (CT) scan and the presence of intracranial hypertension but not AKI. Hospital mortality was independently associated with initial GSC 3 to 5, worst TCDB first CT scan, the presence of intracranial hypertension and AKI. The presence of AKI regardless of GCS multiplied risk of death 6.17 times (95% confidence interval (CI): 1.37 to 27.78) (P < 0.02), while ICU hypotension increased the risk of death in patients with initial scores of 3 to 5 on the GCS 4.28 times (95% CI: 1.22 to15.07) (P < 0.05). Conclusions: Low initial GCS, worst first CT scan, intracranial hypertension and AKI determined hospital mortality in severe TBI patients. Besides the direct effect of low GCS on mortality, this neurological condition also is associated with ICU hypotension which increases hospital mortality among patients with severe TBI. These findings add to previous studies that showed that non-neurological complications increase the length of stay and morbidity in the ICU but do not increase mortality, with the exception of AKI and hypotension in low GCS (3 to 5)

    Portuguese 16th to Early 18th Century tin Glazed Ceramics Found at the Tagus Estuary Saltpans

    Get PDF
    UID/NAN/50024/2019 M-ERA-MNT/0002/2015 UIDB/04209/2020 UIDP/04209/2020Salt was extracted from saltpans, in the South shore of Tagus River by evaporation of the salted sea water which penetrates into the estuary. The walls and the bottom of those saltpans were made of local clays to retain the sea water, and ceramic sherds have been used to endure those walls and also to allow people to walk on the saltpans’ walls. Those sherds constitute an example of the ceramics production in Lisbon workshops, starting in the mid-16th century and reaching high levels of quality in the 17th and 18th century. A detailed archaeometric study of 14 selected sherds dated from the 16th to the early 18th century has been made and the conjugation of the information provided by the micro-Raman, XRD and XRF experiments for those sherds and clays collected locally, allowed us the characterisation of the Lisbon ceramics in that period. Three main groups could be identified in the ceramic bodies; all made with locally collected clays of Miocene origin. In the first group, the potters used raw materials from the clay sources located at Santa Catarina area in Lisbon, most probably mixed with Lapa clays, which were fired at a high temperatures, ranging from 850ºC to 950ºC. Gehlenite and quartz are the dominant minerals of these ceramic bodies. In the second and third groups of Lisbon ceramic bodies, made with Prazeres clays, diopside was also detected but with variable amounts of gehlenite. Clay formations mineralogy mainly include kaolinite, muscovite/illite, quartz, calcite, and feldspars (albite and microcline).publishersversionpublishe

    An archaeometric study of lead glazed medieval ceramics (13th-14th centuries) from Santarém

    Get PDF
    UIDB/04004/2020Ceramic sherds from approximately 20 samples of lead-glazed tableware, recovered from diverse archaeological sites, including three repurposed storage pits transformed into dumpsters within the medieval city of Santarém (13th–14th century), underwent a meticulous examination. This investigation utilised techniques such as micro-Raman, ground-state diffuse reflectance absorption, and X-ray fluorescence spectroscopies, in addition to X-ray diffraction and stereomicroscopy. A parallel study was conducted on contemporaneous European ceramics (glazed sherds) sourced from archaeological sites dating back to the 13th–15th centuries in Saintonge (France), Ardenne, Zomergem, and Bruges (Belgium), as well as Surrey–Hampshire, Kingston, and Cheam (England). The first premise for comparing the Santarem samples with European production locations was their frequent commercial relations with Portugal and the frequency of these productions being found in Portugal. The colour of the ceramic bodies is predominantly white or whitish, with a few exhibiting a vivid red hue. Analyses of the fabric, mineralogical, and elemental composition of the sherds suggest that the majority of Santarém’s glazed ceramics were locally or regionally produced, potentially derived from a Pliocene kaolin-rich sand formation. However, this conclusion is not supported by the absence of discovered lead glaze kilns or workshops in Santarém for the late Middle Ages.publishersversionpublishe

    Laboratori d'habilitats: aprenentatge i avaluació dels continguts pràctics de Fisiologia Humana

    Get PDF
    Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Un dels reptes en els ensenyaments amb docència pràctica és avaluar els coneixements i les habilitats que els estudiants adquireixen al laboratori. En aquest sentit, els estudiants de Ciències Mèdiques Bàsiques, actualment Ciències Biomèdiques, durant els cursos 11-12 i 13-14 van participar en el laboratori d’habilitats de l’assignatura Fisiologia Humana I i II. El laboratori d’habilitats consisteix en un laboratori que disposa dels equips i materials que es fan servir a les pràctiques de l’assignatura i que està a lliure disposició dels estudiants en un horari concret. Un cop realitzades les pràctiques, els estudiants poden participar lliurement en el laboratori d’habilitats per consultar dubtes i practicar les habilitats que han adquirit durant el normal desenvolupament de les pràctiques i que seran objecte d’avaluació. L’avaluació es realitza en el mateix laboratori d’habilitats i consisteix en un examen escrit i oral sobre els continguts de pràctiques, a més d’una demostració de les habilitats adquirides. Les habilitats ponderen un 10% en l’avaluació continuada i són avaluades mitjançant una rúbrica que permet al professorat puntuar objectivament l’estudiant. Un cop realitzat l’examen pràctic els estudiants van ser enquestats per tal de conèixer la seva opinió respecte al “laboratori d’habilitats” i al nou sistema d’avaluació de la docència pràctica. La majoria d’estudiants creuen que el laboratori d’habilitats els ha fet treballar i comprendre millor els continguts de les pràctiques (obtenint una puntuació de 4.2 de mitjana dels dos cursos, sobre 5), prefereixen aquest mètode d’avaluació enfront al tradicional, basat en preguntes a l'examen teòric (4.6 sobre 5), els ha resultat interessant (4.4 sobre 5) i globalment l’experiència els ha resultat satisfactòria (4.5 sobre 5). Les puntuacions obtingudes en l’examen d’habilitats han estat de 8,5 sobre 10 (de mitjana en els darrers 2 cursos). Així, es pot concloure que aquesta metodologia docent, àmpliament acceptada pels estudiants, permet reforçar i avaluar les habilitats treballades al laboratori
    corecore