Desenvolvimento de materiais baseados em grafeno para aplicações ambientais

As terras raras (TR), elementos associados ao desenvolvimento tecnológico, tornaram-se fundamentais para o mundo tal como o conhecemos hoje. Estes elementos são de difícil extração, a qual tem impactos ambientais negativos associados, e apresentam elevado risco de fornecimento devido à crescente procura. Assim, torna-se relevante explorar formas alternativas de obtenção desses elementos. A água, como consequência da atividade de mineração, descarga de efluentes industriais e lixo eletrónico, poderá ser uma fonte secundária para a obtenção de TR. Aproveitando as potencialidades da sorção, como a simplicidade, versatilidade e viabilidade económica, e dos nanocompósitos baseados em grafeno, que têm uma elevada área superficial, esta dissertação teve como objetivo a recuperação de TR a partir de água contaminada. Os elementos em estudo foram o neodímio (Nd), európio (Eu), térbio (Tb), disprósio (Dy) e ítrio (Y), por serem os elementos considerados mais críticos, e o lantânio (La) devido à sua diversificada utilização. Optou-se por estudar sistemas multielementares, contendo os elementos em concentrações relativamente baixas (100 μg L-1) de modo a mimetizar condições reais, para as quais existem lacunas detetadas na literatura. Foram testados vários sorventes baseados em óxido de grafeno, sendo que o óxido de grafeno funcionalizado com polietilenoimina (GO-PEI) foi o que se revelou mais promissor. A sua estrutura, morfologia e carga superficial foram estudadas por FTIR-ATR, SEM e PZ, respetivamente. Os ensaios de sorção incluíram diferentes parâmetros: dose de sorvente, matriz de água e pH inicial da solução. Os resultados mostraram que para doses ≥ a 25 mg L-1 obtêm-se remoções superiores a 90 %, e que a sorção é positivamente afetada pelo aumento da dose de sorvente. O pH 6 foi considerado o ótimo e não se observaram diferenças relevantes entre água ultrapura e água mineral engarrafada, evidenciando a potencial aplicabilidade do GO-PEI num contexto real. Os dados experimentais foram ajustados através da utilização dos modelos cinéticos de pseudo primeira ordem, pseudo segunda ordem e Elovich. O modelo que apresentou melhor desempenho foi o modelo de pseudo segunda ordem, inferindo-se, assim, que o mecanismo que controla a sorção é a quimiossorção. Os dados experimentais de equilíbrio foram ajustados com recurso aos modelos de Langmuir, Freundlich e SIPS e o modelo que melhor ajustou os dados foi o de SIPS. Foi estimada a capacidade máxima de sorção para os elementos, que variou entre 5494±366 μg g-1 e 6876±1023 μg g-1 para o Y(III) e Eu(III), respetivamente. Os resultados obtidos indicam que se trata de um processo promissor, com remoções rápidas e elevadas para todos os elementos em estudo.Rare earth elements (REE) are associated with technological development, and have become central to the world as we know it today. These elements are of difficult extraction from ores, which process is associated with negative environmental impacts, and present a high supply risk due to increasing demand. Thus, it becomes relevant to explore alternative ways of obtaining these elements. Water from mining activity, industrial effluent discharge and electronic waste, may be a secondary source for obtaining REE. Taking advantage of the potential of sorption, such as simplicity, versatility and economic viability, and of graphene-based nanocomposites, which have a high surface area, this dissertation aimed to recover REE from contaminated water. The elements under study were neodymium (Nd), europium (Eu), terbium (Tb), dysprosium (Dy) and yttrium (Y), being considered the most critical elements, and lanthanum (La) due to its diverse use. Multi-elemental systems, containing the elements in relatively low concentrations (100 μg L-1) were selected to mimic real conditions, for which there are gaps detected in the literature. Several sorbents based on graphene oxide were tested, and graphene oxide functionalized with polyethylenimine (GO-PEI) showed to be the most promising. Its structure, morphology and surface charge were studied by FTIR-ATR, SEM and PZ, respectively. Sorption assays included different parameters: sorbent dose, water type and initial pH of the solution. The results showed that for doses ≥ 25 mg L-1, removals greater than 90 % are obtained, and that sorption is positively affected by the increase of sorbent dose. The pH 6 was considered optimal and no relevant differences were observed between ultrapure water and mineral bottled water, evidencing the potential applicability of GO-PEI in a real context. The experimental data were adjusted using the pseudo first order, pseudo second order and Elovich kinetic models. The model with the best performance was the pseudo second order model, thus inferring that the mechanism that controls sorption is chemisorption. The experimental equilibrium data were adjusted using the Langmuir, Freundlich and SIPS models and the best fit model was that achieved by the SIPS model. The maximum sorption capacity for the elements, were in the range of 5494 ± 366 μg g-1 to 6876 ± 1023 μg g-1 for Y (III) and Eu (III), respectively. The results indicate that this is a promising process, with fast and high removals for all elements under study.CENTRO 2020, FEDER, FCT, CENTRO-01-0145-FEDER-030513, TEMA-UA, CESAM-UA.Mestrado em Engenharia Químic

Práticas artísticas no ensino básico e secundário

A mediação entre os conteúdos culturais e a Educação Artística formal tem emergido como uma distinta área de inovação e de intervenção, como o mostram os 18 artigos selecionados nesta nona edição da revista Matéria-Prima.Entre a identidade, fundada nos focos de conhecimento local, e uma inserção integrada nos problemas e conteúdos globais joga-se a problematização da Educação Artística. As propostas articulam quer discursos curatoriais (museu, bienal, exposição), como ações de mediação visando uma expansão das atividades, a que se juntam as reflexões sobre a realidade da formação de professores, nas suas diversas modalidades, em diversas realidades sociais.Propiciam-se oportunidades de ações de intervenção, concertadas ou não, entre os agentes artísticos e os educadores. O resultado pode ser potenciado se se conseguir uma perspetiva informada e integrada das realidades artísticas: pede-se a todos os intervenientes mais integração e disponibilidade para um conhecimento mútuo consequente.info:eu-repo/semantics/publishedVersio

Integrated monitoring of mola mola behaviour in space and time

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of finescale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) videorecorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (r(s) = 0.184, p < 0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's finescale behaviour observed over a two weeks in May 2014

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6&nbsp;years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P &lt; 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100&nbsp;years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others