Thermomechanical Analysis on Ti-Ni Shape Memory Helical Springs Under Cyclic Tensile Loads

Recent developments of smart actuators using the two-way shape memory effect (TWSME) for industrial applications are becoming more common in scientific research. Shape memory alloys (SMAs) present some characteristics, which make it unique material to be use in applications that require strength and shape recovery. Ti-Ni alloys are an important class of memory alloys due to the shape memory effect (SME) and superelasticity (SE), which are govern by the thermoelastic martensitic transformation (MT). This material was been used to manufacture smart actuators for mechanical industry devices and several other applications in areas as medicine, robotics, aerospace, petroleum and gas industries. In general, Ti-Ni SMAs undergo one-step (austenite martensite) transformation, but in some cases, there exists intermediate R-phase giving rise two-step (austenite R-phase martensite) transformation. This investigation is interesting due to the importance of knowing the actuators response to external stimulus (heat source, electrical current and/or external stress). In this work it was investigated the mechanical behavior in helical actuators produced from Ti-Ni alloy commercial wires. Different characterization techniques were employ for analyzing the samples as: differential scanning calorimeter (DSC), scanning electron microscopy (SEM), optical microscopy (OM) and a non-commercial apparatus developed to apply an external traction stress in helical actuators during thermal cycles

Eficácia de novas abordagens terapêuticas para a doença de Chagas: uma revisão integrativa

A doença de Chagas é uma doença tropical negligenciada, caracterizada pela infecção humana crônica decorrente do protozoário Trypanosoma cruzi e que afeta cerca de 8 a 10 milhões de pessoas em todo o mundo. O presente estudo de revisão buscou avaliar novos avanços e atualizações na abordagem terapêutica da doença de Chagas, documentados por meio de estudos clínicos e randomizados. Trata-se de uma pesquisa de revisão integrativa realizada por meio da base de dados PubMed, que levou em consideração os seguintes critérios de inclusão: ensaios clínicos e testes controlados e randomizados; artigos publicados nos últimos três anos; que possuíam texto completo disponível e que abordassem acerca da terapêutica da doença de Chagas. Ficou constatado que o nifurtimox ajustado para idade e peso por 60 dias alcançou uma resposta sorológica 12 meses após o tratamento que foi superior ao placebo, sendo tolerado e com um perfil de segurança favorável em crianças com doença de Chagas. Ademais, o benznidazol, em associação com o fosravuconazol, conseguiu induzir resposta antiparasitária e eficaz, independente da duração do tratamento, dose ou combinação com o fosravuconazol, sendo bem tolerado em pacientes adultos na fase crônica da doença de Chagas. Por fim, o fexinidazol possibilitou a eliminação precoce e completa do T. cruzi que se manteve por 12 meses. No entanto, 20% dos pacientes tratados com fexinidazol desenvolveram neutropenia, além de apresentarem elevação de enzimas hepáticas durante o período de acompanhamento, sendo aplicada a interrupção do tratamento

A Dança Descontrolada do Coração: Uma Revisão Sistemática sobre Taquiarritmias - Estratégias de Diagnóstico, Abordagens Terapêuticas e Desafios Emergentes

Introduction: A profound understanding of these arrhythmias extends beyond mere identification of irregular patterns in the electrocardiogram. It demands a meticulous analysis of diagnostic strategies, aiming not only for early detection but also for the precise differentiation among various forms of tachyarrhythmias.   Methodology: The present study comprises a systematic review addressing tachyarrhythmias, with a focus on Diagnostic Strategies, Therapeutic Approaches, and Emerging Challenges. The investigation was conducted on the PUBMED platform, using specific MESH descriptors such as Tachycardia, Therapeutics, and Diagnosis. Results: Similar to atrial fibrillation, the therapeutic approach to atrial flutter faces emerging challenges. The individualization of treatment, considering the specific characteristics of each patient, remains a critical aspect, especially when dealing with more vulnerable populations such as the elderly. Furthermore, the integration of innovative technologies, like artificial intelligence and remote monitoring devices, presents opportunities and challenges in the ongoing management of atrial flutter. Conclusion: Clinical challenges manifest as opportunities for significant advancements in the management of cardiac arrhythmias. Early identification, prevention of complications, and the pursuit of more effective therapeutic approaches are goals that permeate the core of contemporary cardiological practice.Introdução: A compreensão profunda dessas arritmias vai além da mera identificação de padrões irregulares no eletrocardiograma. Ela demanda uma análise minuciosa das estratégias de diagnóstico, visando não apenas a detecção precoce, mas também a diferenciação precisa entre as várias formas de taquiarritmias. Metodologia: A presente pesquisa consiste em uma revisão sistemática abordando as Taquiarritmias, com foco nas Estratégias de Diagnóstico, Abordagens Terapêuticas e Desafios Emergentes. A investigação foi conduzida na plataforma PUBMED, utilizando descritores MESH específicos, tais como Tachycardia, Therapeutics e Diagnosis. Resultado: semelhante à fibrilação atrial, a abordagem terapêutica do flutter atrial enfrenta desafios emergentes. A individualização do tratamento, considerando as características específicas de cada paciente, permanece um aspecto crítico, especialmente ao lidar com populações mais vulneráveis, como idosos. Além disso, a integração de tecnologias inovadoras, como a inteligência artificial e dispositivos de monitoramento remoto, apresenta oportunidades e desafios na gestão contínua do flutter atrial. Conclusão: Os desafios clínicos apresentam-se como oportunidades para avanços significativos na gestão das arritmias cardíacas. A identificação precoce, a prevenção de complicações e a busca por abordagens terapêuticas mais eficazes são metas que permeiam o cerne da prática cardiológica contemporânea

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

Lidar Observations in South America. Part I - Mesosphere and Stratosphere

South America covers a large area of the globe and plays a fundamental function in its climate change, geographical features, and natural resources. However, it still is a developing area, and natural resource management and energy production are far from a sustainable framework, impacting the air quality of the area and needs much improvement in monitoring. There are significant activities regarding laser remote sensing of the atmosphere at different levels for different purposes. Among these activities, we can mention the mesospheric probing of sodium measurements and stratospheric monitoring of ozone, and the study of wind and gravity waves. Some of these activities are long-lasting and count on the support from the Latin American Lidar Network (LALINET). We intend to pinpoint the most significant scientific achievements and show the potential of carrying out remote sensing activities in the continent and show its correlations with other earth science connections and synergies. In Part I of this chapter, we will present an overview and significant results of lidar observations in the mesosphere and stratosphere. Part II will be dedicated to tropospheric observations

Lidar Observations in South America. Part II - Troposphere

In Part II of this chapter, we intend to show the significant advances and results concerning aerosols’ tropospheric monitoring in South America. The tropospheric lidar monitoring is also supported by the Latin American Lidar Network (LALINET). It is concerned about aerosols originating from urban pollution, biomass burning, desert dust, sea spray, and other primary sources. Cloud studies and their impact on radiative transfer using tropospheric lidar measurements are also presented

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

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