23 research outputs found
Influence of Processing Route on the Surface Reactivity of Cu47Ti33Zr11Ni6Sn2Si1 Metallic Glass
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
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
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Analytical Modeling of Cooling Rates in PBF-LB/M of Bulk Metallic Glasses
Additive manufacturing through laser powder bed fusion (PBF-LB/M) inheres great
potential for the processing of bulk metallic glasses (BMGs). The size-independent high cooling
rates during the process benefit the fabrication of large and elaborate amorphous components.
Albeit, partial crystallization poses a challenge in additively manufactured BMGs, potentially
limiting the resulting mechanical properties. In this matter, the complex thermal history during
processing often states a remaining uncertainty. Besides in situ measurements and numerical
estimations, analytical models can be used to achieve a deeper understanding of the transient
temperature evolution. In this work, an iterative solution to the analytical Rosenthal equation is
developed and applied to ZrCuAlNb- and CuTiZrNi-BMGs to predict melt pool dimensions
and cooling rates during PBF-LB/M. Therefore, temperature-dependent thermal properties are
determined via laser flash measurements. The effective absorptivity of the two materials is
measured, and single-line experiments were performed as a validation for the approach.Mechanical Engineerin
Pervasive gaps in Amazonian ecological research
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
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 mediciĂłn de la presiĂłn arterial (PA) es un procedimiento OBLIGATORIO en cualquier atenciĂłn mĂ©dica o realizado por diferentes profesionales de la salud. Sin embargo, todavĂa se realiza comĂşnmente sin los cuidados tĂ©cnicos necesarios. Dado que el diagnĂłstico se basa en la mediciĂłn de la PA, es claro el cuidado que debe haber con las tĂ©cnicas, los mĂ©todos y los equipos utilizados en su realizaciĂłn.
Debemos enfatizar que una vez realizado el diagnĂłstico, todas las investigaciones y tratamientos a corto, mediano y largo plazo se basan en los resultados de la mediciĂłn de la PA. Por lo tanto, las tĂ©cnicas y/o equipos inadecuados pueden llevar a diagnĂłsticos incorrectos, subestimando o sobreestimando valores y resultando en conductas inadecuadas y pĂ©rdidas significativas para la salud y la economĂa 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 mediciĂłn de la PA (descrita a continuaciĂłn) generalmente se realiza mediante el mĂ©todo tradicional, la llamada mediciĂłn casual o de consultorio. Con el tiempo, se han agregado alternativas a travĂ©s 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 pĂşblicos. 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 perĂodos más largos (MAPA).
Algunos aspectos en la mediciĂłn de la PA pueden interferir en la obtenciĂłn de resultados confiables y, en consecuencia, causar daños en las decisiones a tomar. Estos incluyen la importancia de usar valores promedio, la variaciĂłn de la PA durante el dĂa y la variabilidad a corto plazo. Estos aspectos han alentado la realizaciĂłn de un mayor nĂşmero 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 precisiĂłn, cuando se usan juntos, detectan la hipertensiĂłn de bata blanca (HBB), la hipertensiĂłn enmascarada (HM), las alteraciones de la PA durante el sueño y la hipertensiĂłn resistente (HR) (definida en el CapĂtulo 2 de esta guĂa), están ganando cada vez más importancia.
Teniendo en cuenta estos detalles, debemos enfatizar que la informaciĂłn relacionada con el diagnĂłstico, la clasificaciĂłn y el establecimiento de objetivos todavĂa se basa en la mediciĂłn de la presiĂłn arterial en el consultorio, y por esta razĂłn, se debe prestar toda la atenciĂłn a la ejecuciĂłn adecuada de este procedimiento.A hipertensĂŁo arterial (HA) Ă© 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 insuficiĂŞncia renal. AlĂ©m disso, Ă© 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 diagnĂłstico, toda a investigação e os tratamentos de curto, mĂ©dio e longo prazos sĂŁo feitos com base nos resultados da medida da PA. Assim, tĂ©cnicas e/ou equipamentos inadequados podem levar a diagnĂłsticos incorretos, tanto subestimando quanto superestimando valores e levando a condutas inadequadas e grandes prejuĂzos Ă saĂşde e Ă 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) Ă© habitualmente feita pelo mĂ©todo tradicional, a assim chamada medida casual ou de consultĂłrio. Ao longo do tempo, foram agregadas alternativas a ela, mediante o uso de equipamentos semiautomáticos ou automáticos pelo prĂłprio paciente, nas salas de espera ou fora do consultĂłrio, em sua prĂłpria residĂŞncia ou em espaços pĂşblicos. Um passo adiante foi dado com o uso de equipamentos semiautomáticos providos de memĂłria que permitem medidas sequenciais fora do consultĂłrio (AMPA; ou MRPA) e outros automáticos que permitem medidas programadas por perĂodos mais prolongados (MAPA).
Alguns aspectos na medida da PA podem interferir na obtenção de resultados fidedignos e, consequentemente, causar prejuĂzo nas condutas a serem tomadas. Entre eles, estĂŁo: a importância de serem utilizados valores mĂ©dios, a variação da PA durante o dia e a variabilidade a curto prazo. Esses aspectos tĂŞm estimulado a realização de maior nĂşmero de medidas em diversas situações, e as diferentes diretrizes tĂŞm preconizado o uso de equipamentos que favoreçam essas ações. Ganham cada vez mais espaço os equipamentos que realizam MRPA ou MAPA, que, alĂ©m de permitirem maior precisĂŁo, 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 CapĂtulo 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
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
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
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
As diferenças de gĂŞnero sĂŁo assunto que diz respeito a todos nĂłs, visto que vivemos em um ambiente social onde lidar com tais diferenças torna-se imprescindĂvel a todo momento. Dizer que as diferenças de gĂŞnero sĂŁo construções sociais e variam de acordo com cada sociedade nĂŁo Ă© novidade. O presente estudo busca identificar atravĂ©s da literatura, como as diferenças entre homens e mulheres interfere nos relacionamentos afetivos heterossexuais, de forma a identificar quais sĂŁo 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 revisĂŁo bibliográfica, atravĂ©s da qual buscamos artigos e bibliografias que apontem contribuições para a reflexĂŁo do tema proposto.
Palavras-chave: Diferença; Gênero; Heterossexuais