Neutral-cluster implantation in polymers by computer experiments

In this work we perform atomistic model potential molecular dynamics simulations by means of state-of-the art force-fields to study the implantation of a single Au nanocluster on a Polydimethylsiloxane substrate. All the simulations have ben performed on realistic substrate models containing up to 4.6 millions of atoms having depths up to 90 nm and lateral dimensions up to 25 nm. We consider both entangled-melt and cross-linked Polydimethylsiloxane amorphous structures. We show that even a single cluster impact on the Polydimethylsiloxane substrate remarkably changes the polymer local temperature and pressure. Moreover we observe the presence of craters created on the polymer surface having lateral dimensions comparable to the cluster radius and depths strongly dependent on the implantation energy. Present simulations suggest that the substrate morphology is largely affected by the cluster impact and that most-likely such modifications favor the the penetration of the next impinging clusters

Electronic and optical properties of nanometer-sized chromophores in bacterial cellulose

We present a computational investigation on the electronic and optical properties of the principal chromophores found in bacterial cellulose (BC). We focus on the three key structures that were isolated from aged BC: (A) 2,5Dihydroxy[ 1,4]benzoquinone, (B) 5,8Dihydroxy[ 1,4]naphthoquinone (C) 2,5Dihydroxyacetophenone, while (D) p-benzoquinone was used as a reference structure. For all the isolated molecules, we performed allelectrons Density Functional Theory (DFT) and Time Dependent DFT (TDDFT) calculations with a localized Gaussian basisset and the hybrid exchangecorrelation functionals B3LYP and PBE0. We computed and analyzed their electronic and optical properties and compare with available experimental data

O Custo da Sustentabilidade: Transição Energética à luz dos Marcos Normativos de Empresas e Direitos Humanos e ESG

This paper aims to understand cost involving the process of energy transition to a more sustainable planet considering Business and Human Rights and ESG frameworks, since this transition is driven by the urgent need to address the irreversible impacts of climate change, requiring international society and States to adapt to new realities. A major negative aspect of developing clean and sustainable energy is the increasing reliance on minerals often extracted in Global South States, marked by economic, social, and cultural disparities, and non-democratic structures. These conditions frequently lead to human rights violations, as highlighted in recent reports on illegal mining in Myanmar. The Non-Governmental Organization Global Witness reported serious human rights and environmental abuses in Myanmar, where rare minerals are extracted for EVs and wind turbines. These violations have been exacerbated by the political instability following the 2021 military coup. This work critically examines how energy transition dynamics must be redesigned to avoid replicating exploitative practices commonly seen in the Global North-South corporate dynamics. It emphasizes, on this regard, the need for these processes to support, rather than undermine, democratic and human rights standards. The analysis draws on several references: BHR frameworks, ESG corporate practices, academic research on human rights violations in supply chains, TWAIL literature, and academic considerations on the role of democracy in human rights protection and its close connection to sustainability in a broad sense.This paper aims to understand cost involving the process of energy transition to a more sustainable planet considering Business and Human Rights and ESG frameworks, since this transition is driven by the urgent need to address the irreversible impacts of climate change, requiring international society and States to adapt to new realities. A major negative aspect of developing clean and sustainable energy is the increasing reliance on minerals often extracted in Global South States, marked by economic, social, and cultural disparities, and non-democratic structures. These conditions frequently lead to human rights violations, as highlighted in recent reports on illegal mining in Myanmar. The Non-Governmental Organization Global Witness reported serious human rights and environmental abuses in Myanmar, where rare minerals are extracted for EVs and wind turbines. These violations have been exacerbated by the political instability following the 2021 military coup. This work critically examines how energy transition dynamics must be redesigned to avoid replicating exploitative practices commonly seen in the Global North-South corporate dynamics. It emphasizes, on this regard, the need for these processes to support, rather than undermine, democratic and human rights standards. The analysis draws on several references: BHR frameworks, ESG corporate practices, academic research on human rights violations in supply chains, TWAIL literature, and academic considerations on the role of democracy in human rights protection and its close connection to sustainability in a broad sense.Este artigo tem como objetivo compreender os custos que envolvem o processo de transição energética para um planeta mais sustentável considerando os marcos de Direitos Humanos e Empresas e ESG, uma vez que esta transição é impulsionada pela necessidade urgente de enfrentar os impactos irreversíveis das alterações climáticas, exigindo que a sociedade internacional e os Estados se adaptem às novas realidades. Um aspecto negativo importante do desenvolvimento de energia limpa e sustentável é a crescente dependência de minerais frequentemente extraídos nos Estados do Sul Global, marcados por disparidades econômicas, sociais e culturais e por estruturas não democráticas. Estas condições conduzem frequentemente a violações dos direitos humanos, conforme salientado em relatórios recentes sobre a mineração ilegal em Mianmar. A Organização Não-Governamental Global Witness relatou graves violações dos direitos humanos e do meio-ambiente em Myanmar, onde minerais raros são extraídos para veículos eléctricos e turbinas eólicas. Estas violações foram exacerbadas pela instabilidade política que se seguiu ao golpe militar de 2021. Este trabalho examina criticamente como a dinâmica de transição energética deve ser redesenhada para evitar a replicação de práticas de exploração comumente vistas na dinâmica corporativa envolvendo o Norte e o Sul Global. Enfatiza, nesse sentido, a necessidade de estes processos apoiarem, em vez de prejudicarem, os padrões democráticos e de direitos humanos. A análise baseia-se em diversas referências: estruturas BHR, práticas empresariais ESG, investigação acadêmica sobre violações dos direitos humanos nas cadeias de abastecimento, literatura TWAIL e considerações acadêmicas sobre o papel da democracia na proteção dos direitos humanos e a sua estreita ligação com a sustentabilidade num sentido amplo

How are climate policies assessed in emerging economies? A study of ex-ante policy appraisal in Brazil, China, and India

Effective mitigation of climate change requires a robust set of policy interventions. Existing policy appraisal frameworks and approaches impact the design and choice of these policy options. However, their application to transformative climate policy can present several shortcomings. In light of criticism around current appraisal methods, we review the climate policy appraisal landscape and interview policy experts in three major emerging economies: Brazil, China and India. Little research has been done on the perception, approach, and practice of policy appraisal in these countries, even though they will have a significant impact on global progress to mitigate climate change. We find that policy appraisal in Brazil, China, and India is supported by guidelines, but the detail and implementation of those guidelines vary significantly. Cost–benefit analysis (CBA) is the prevailing decision-making framework in both Brazil and India whereas multi-criteria analysis is the dominant framework in China. Practitioners appear to understand CBA and its limitations well but also value its usability and the perception of robustness. Across all countries, political considerations can outweigh appraisal findings; respondents suggested this can be negative, in the sense that appraisal results are sometimes ignored, but can also be positive in the sense that other objectives are considered. Existing approaches present several limitations, particularly regarding transformational change, which could hamper progress to formulate and implement effective climate and energy policy

Deciphering Molecular Mechanisms of Interface Buildup and Stability in Porous Si/Eumelanin Hybrids

Porous Si/eumelanin hybrids are a novel class of organic–inorganic hybrid materials that hold considerable promise for photovoltaic applications. Current progress toward device setup is, however, hindered by photocurrent stability issues, which require a detailed understanding of the mechanisms underlying the buildup and consolidation of the eumelanin–silicon interface. Herein we report an integrated experimental and computational study aimed at probing interface stability via surface modification and eumelanin manipulation, and at modeling the organic–inorganic interface via formation of a 5,6-dihydroxyindole (DHI) tetramer and its adhesion to silicon. The results indicated that mild silicon oxidation increases photocurrent stability via enhancement of the DHI–surface interaction, and that higher oxidation states in DHI oligomers create more favorable conditions for the efficient adhesion of growing eumelanin

Exercício e ciclo circadiano induzem variações na contagem de leucócitos sangüineos em jovens jogadores de futebol

O propósito deste estudo6 foi investigar a influência do ciclo circadiano e do exercício na contagem de leucócitos sangüineos. Amostras de sangue foram coletadas antes e após o Yo-Yo Endurance Test em jovens jogadores de futebol (13-16 anos). Os atletas que treinavam pela manhã (12 jovens) realizaram os testes pela manhã (8:00 e 9:30), e os que treinavam à tarde (16 jovens) realizaram os testes à tarde (16:00 e 17:30). Os números de leucócitos, neutrófilos e linfócitos foram significantemente aumentados após o teste pela manhã. Também foram significantes os aumentos dos números de leucócitos, neutrófilos, linfócitos no grupo que realizou o teste no período da tarde incluindo os eosinófilos. As concentrações basais de leucócitos, neutrófilos, linfócitos e monócitos no sangue apresentaram-se significantemente mais elevadas no grupo da tarde. Os aumentos dos números absolutos de leucócitos, linfócitos e eosinófilos presentes no sangue foram maiores no final do teste no grupo da tarde. O Yo-Yo Endurance modificou as concentrações de leucócitos, provavelmente pela ação das catecolaminas. Pela manhã ficou observado que as concentrações de leucócitos responderam menos ao estresse do exercício, talvez em função das variações nos níveis dos glicocorticóides, pois não existiu correlação com o VO2max.

Orientações para Realização de Exames de Ressonância Magnética Nuclear em Pacientes com Dispositivos Eletrônicos Cardíacos

Estima-se que até 75% dos pacientes com dispositivos cardíacos eletrônicos implantáveis (DCEIs) terão indicação de exame de ressonância nuclear magnética (RNM) ao longo da vida. Pelas características dos dispositivos, esses foram excluídos historicamente do rol de pacientes considerados elegíveis ao exame

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery