23 research outputs found

    Influence of Processing Route on the Surface Reactivity of Cu47Ti33Zr11Ni6Sn2Si1 Metallic Glass

    Get PDF
    Recently, laser additive manufacturing (AM) techniques have emerged as a promising alternative for the synthesis of bulk metallic glasses (BMGs) with massively increased freedom in part size and geometry, thus extending their economic applicability of this material class. Nevertheless, porosity, compositional inhomogeneity, and crystallization display themselves to be the emerging challenges for this processing route. The impact of these “defects” on the surface reactivity and susceptibility to corrosion was seldom investigated but is critical for the further development of 3D-printed BMGs. This work compares the surface reactivity of cast and additively manufactured (via laser powder bed fusion—LPBF) Cu47Ti33Zr11Ni6Sn2Si1 metallic glass after 21 days of immersion in a corrosive HCl solution. The cast material presents lower oxygen content, homogeneous chemical distribution of the main elements, and the surface remains unaffected after the corrosion experimentation based on vertical scanning interferometry (VSI) investigation. On the contrary, the LPBF material presents a considerably higher reactivity seen through crack propagations on the surface. It exhibits higher oxygen content, heterogeneous chemical distribution, and presence of defects (porosity and cracks) generated during the manufacturing process

    Laser powder bed fusion of Cu-Ti-Zr-Ni bulk metallic glasses in the Vit101 alloy system

    Get PDF
    Laser powder bed fusion (PBF-LB/M) of bulk metallic glasses (BMGs) has experienced growing scientific and industrial interest in the last years, with a special focus on application relevant systems based on zirconium. The high cooling rates and the layer-wise build-up process allow overcoming size and geometry limitations typical for conventional casting routes. Yet, the novel production approach requires different alloy characteristics than casting processes. The present work reports for the first time on the PBF-LB/M-processing of three CuTi-based bulk metallic glass formers in the Vit101 system, allowing to exceed the mechanical performance of most additively formed Zr-based BMGs. Furthermore, the influence of alloy properties like thermal stability and toughness on the PBF-LB/M applicability are systematically studied. Thermal stability plays a minor role to produce amorphous specimen, while notch toughness is found to be a more crucial aspect to achieve parts with low defect density and resulting high mechanical performance. The results suggest fundamentally different alloy development strategies adapted to the needs of the PBF-LB/M-process, leaving classical casting-based optimization of glass forming ability behind and evolving towards a rather toughness-oriented optimization

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Diretrizes Brasileiras de Medidas da Pressão Arterial Dentro e Fora do Consultório – 2023

    Get PDF
    Hypertension is one of the primary modifiable risk factors for morbidity and mortality worldwide, being a major risk factor for coronary artery disease, stroke, and kidney failure. Furthermore, it is highly prevalent, affecting more than one-third of the global population. Blood pressure measurement is a MANDATORY procedure in any medical care setting and is carried out by various healthcare professionals. However, it is still commonly performed without the necessary technical care. Since the diagnosis relies on blood pressure measurement, it is clear how important it is to handle the techniques, methods, and equipment used in its execution with care. It should be emphasized that once the diagnosis is made, all short-term, medium-term, and long-term investigations and treatments are based on the results of blood pressure measurement. Therefore, improper techniques and/or equipment can lead to incorrect diagnoses, either underestimating or overestimating values, resulting in inappropriate actions and significant health and economic losses for individuals and nations. Once the correct diagnosis is made, as knowledge of the importance of proper treatment advances, with the adoption of more detailed normal values and careful treatment objectives towards achieving stricter blood pressure goals, the importance of precision in blood pressure measurement is also reinforced. Blood pressure measurement (described below) is usually performed using the traditional method, the so-called casual or office measurement. Over time, alternatives have been added to it, through the use of semi-automatic or automatic devices by the patients themselves, in waiting rooms or outside the office, in their own homes, or in public spaces. A step further was taken with the use of semi-automatic devices equipped with memory that allow sequential measurements outside the office (ABPM; or HBPM) and other automatic devices that allow programmed measurements over longer periods (HBPM). Some aspects of blood pressure measurement can interfere with obtaining reliable results and, consequently, cause harm in decision-making. These include the importance of using average values, the variation in blood pressure during the day, and short-term variability. These aspects have encouraged the performance of a greater number of measurements in various situations, and different guidelines have advocated the use of equipment that promotes these actions. Devices that perform HBPM or ABPM, which, in addition to allowing greater precision, when used together, detect white coat hypertension (WCH), masked hypertension (MH), sleep blood pressure alterations, and resistant hypertension (RHT) (defined in Chapter 2 of this guideline), are gaining more and more importance. Taking these details into account, we must emphasize that information related to diagnosis, classification, and goal setting is still based on office blood pressure measurement, and for this reason, all attention must be given to the proper execution of this procedure.La hipertensión arterial (HTA) es uno de los principales factores de riesgo modificables para la morbilidad y mortalidad en todo el mundo, siendo uno de los mayores factores de riesgo para la enfermedad de las arterias coronarias, el accidente cerebrovascular (ACV) y la insuficiencia renal. Además, es altamente prevalente y afecta a más de un tercio de la población mundial. La medición de la presión arterial (PA) es un procedimiento OBLIGATORIO en cualquier atención médica o realizado por diferentes profesionales de la salud. Sin embargo, todavía se realiza comúnmente sin los cuidados técnicos necesarios. Dado que el diagnóstico se basa en la medición de la PA, es claro el cuidado que debe haber con las técnicas, los métodos y los equipos utilizados en su realización. Debemos enfatizar que una vez realizado el diagnóstico, todas las investigaciones y tratamientos a corto, mediano y largo plazo se basan en los resultados de la medición de la PA. Por lo tanto, las técnicas y/o equipos inadecuados pueden llevar a diagnósticos incorrectos, subestimando o sobreestimando valores y resultando en conductas inadecuadas y pérdidas significativas para la salud y la economía de las personas y las naciones. Una vez realizado el diagnóstico correcto, a medida que avanza el conocimiento sobre la importancia del tratamiento adecuado, con la adopción de valores de normalidad más detallados y objetivos de tratamiento más cuidadosos hacia metas de PA más estrictas, también se refuerza la importancia de la precisión en la medición de la PA. La medición de la PA (descrita a continuación) generalmente se realiza mediante el método tradicional, la llamada medición casual o de consultorio. Con el tiempo, se han agregado alternativas a través del uso de dispositivos semiautomáticos o automáticos por parte del propio paciente, en salas de espera o fuera del consultorio, en su propia residencia o en espacios públicos. Se dio un paso más con el uso de dispositivos semiautomáticos equipados con memoria que permiten mediciones secuenciales fuera del consultorio (AMPA; o MRPA) y otros automáticos que permiten mediciones programadas durante períodos más largos (MAPA). Algunos aspectos en la medición de la PA pueden interferir en la obtención de resultados confiables y, en consecuencia, causar daños en las decisiones a tomar. Estos incluyen la importancia de usar valores promedio, la variación de la PA durante el día y la variabilidad a corto plazo. Estos aspectos han alentado la realización de un mayor número de mediciones en diversas situaciones, y diferentes pautas han abogado por el uso de equipos que promuevan estas acciones. Los dispositivos que realizan MRPA o MAPA, que además de permitir una mayor precisión, cuando se usan juntos, detectan la hipertensión de bata blanca (HBB), la hipertensión enmascarada (HM), las alteraciones de la PA durante el sueño y la hipertensión resistente (HR) (definida en el Capítulo 2 de esta guía), están ganando cada vez más importancia. Teniendo en cuenta estos detalles, debemos enfatizar que la información relacionada con el diagnóstico, la clasificación y el establecimiento de objetivos todavía se basa en la medición de la presión arterial en el consultorio, y por esta razón, se debe prestar toda la atención a la ejecución adecuada de este procedimiento.A hipertensão arterial (HA) é um dos principais fatores de risco modificáveis para morbidade e mortalidade em todo o mundo, sendo um dos maiores fatores de risco para doença arterial coronária, acidente vascular cerebral (AVC) e insuficiência renal. Além disso, é altamente prevalente e atinge mais de um terço da população mundial. A medida da PA é procedimento OBRIGATÓRIO em qualquer atendimento médico ou realizado por diferentes profissionais de saúde. Contudo, ainda é comumente realizada sem os cuidados técnicos necessários. Como o diagnóstico se baseia na medida da PA, fica claro o cuidado que deve haver com as técnicas, os métodos e os equipamentos utilizados na sua realização. Deve-se reforçar que, feito o diagnóstico, toda a investigação e os tratamentos de curto, médio e longo prazos são feitos com base nos resultados da medida da PA. Assim, técnicas e/ou equipamentos inadequados podem levar a diagnósticos incorretos, tanto subestimando quanto superestimando valores e levando a condutas inadequadas e grandes prejuízos à saúde e à economia das pessoas e das nações. Uma vez feito o diagnóstico correto, na medida em que avança o conhecimento da importância do tratamento adequado, com a adoção de valores de normalidade mais detalhados e com objetivos de tratamento mais cuidadosos no sentido do alcance de metas de PA mais rigorosas, fica também reforçada a importância da precisão na medida da PA. A medida da PA (descrita a seguir) é habitualmente feita pelo método tradicional, a assim chamada medida casual ou de consultório. Ao longo do tempo, foram agregadas alternativas a ela, mediante o uso de equipamentos semiautomáticos ou automáticos pelo próprio paciente, nas salas de espera ou fora do consultório, em sua própria residência ou em espaços públicos. Um passo adiante foi dado com o uso de equipamentos semiautomáticos providos de memória que permitem medidas sequenciais fora do consultório (AMPA; ou MRPA) e outros automáticos que permitem medidas programadas por períodos mais prolongados (MAPA). Alguns aspectos na medida da PA podem interferir na obtenção de resultados fidedignos e, consequentemente, causar prejuízo nas condutas a serem tomadas. Entre eles, estão: a importância de serem utilizados valores médios, a variação da PA durante o dia e a variabilidade a curto prazo. Esses aspectos têm estimulado a realização de maior número de medidas em diversas situações, e as diferentes diretrizes têm preconizado o uso de equipamentos que favoreçam essas ações. Ganham cada vez mais espaço os equipamentos que realizam MRPA ou MAPA, que, além de permitirem maior precisão, se empregados em conjunto, detectam a HA do avental branco (HAB), HA mascarada (HM), alterações da PA no sono e HA resistente (HAR) (definidos no Capítulo 2 desta diretriz). Resguardados esses detalhes, devemos ressaltar que as informações relacionadas a diagnóstico, classificação e estabelecimento de metas ainda são baseadas na medida da PA de consultório e, por esse motivo, toda a atenção deve ser dada à realização desse procedimento

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

    Get PDF
    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Influence of Processing Route on the Surface Reactivity of Cu47Ti33Zr11Ni6Sn2Si1 Metallic Glass

    No full text
    Recently, laser additive manufacturing (AM) techniques have emerged as a promising alternative for the synthesis of bulk metallic glasses (BMGs) with massively increased freedom in part size and geometry, thus extending their economic applicability of this material class. Nevertheless, porosity, compositional inhomogeneity, and crystallization display themselves to be the emerging challenges for this processing route. The impact of these “defects” on the surface reactivity and susceptibility to corrosion was seldom investigated but is critical for the further development of 3D-printed BMGs. This work compares the surface reactivity of cast and additively manufactured (via laser powder bed fusion—LPBF) Cu47Ti33Zr11Ni6Sn2Si1 metallic glass after 21 days of immersion in a corrosive HCl solution. The cast material presents lower oxygen content, homogeneous chemical distribution of the main elements, and the surface remains unaffected after the corrosion experimentation based on vertical scanning interferometry (VSI) investigation. On the contrary, the LPBF material presents a considerably higher reactivity seen through crack propagations on the surface. It exhibits higher oxygen content, heterogeneous chemical distribution, and presence of defects (porosity and cracks) generated during the manufacturing process

    AS DIFERENÇAS DE GÊNERO NOS RELACIONAMENTOS AMOROSOS HETEROSESUAIS

    No full text
    As diferenças de gênero são assunto que diz respeito a todos nós, visto que vivemos em um ambiente social onde lidar com tais diferenças torna-se imprescindível a todo momento. Dizer que as diferenças de gênero são construções sociais e variam de acordo com cada sociedade não é novidade. O presente estudo busca identificar através da literatura, como as diferenças entre homens e mulheres interfere nos relacionamentos afetivos heterossexuais, de forma a identificar quais são os comportamentos que mais colaboram para a manutenção de um bom relacionamento, e quais os comportamentos que prejudicam a relação entre os pares. Para isso, temos utilizado a metodologia de  revisão bibliográfica, através da qual buscamos artigos e bibliografias que apontem contribuições para a reflexão do tema proposto. Palavras-chave: Diferença; Gênero; Heterossexuais
    corecore