Organization of chemical reactions by phase separation

All living things are driven by chemical reactions. Reactions provide energy and transform matter. Thus, maintaining the system out of equilibrium. However, these chemical reactions have to be organized in space. One way for this spatial organization is via the process of phase separation. Motivated by the recent discovery of liquid-like droplets in cells, this thesis studies the organization of chemical reactions in phase-separated systems, with and without broken detailed balance. After introducing the underlying thermodynamic principles, we generalize mass-action kinetics to systems with homogeneous compartments formed by phase separation. Here, we discuss the constraints resulting from phase equilibrium on chemical reactions. We study the relaxation kinetics towards thermodynamic equilibrium and investigate non-equilibrium states that arise when detailed balance is broken in the rates of reactions such that phase and chemical equilibria contradict each other. We then turn to spatially continuous systems with spatial gradients within formed compartments. We derive thermodynamic consistent dynamical equations for reactions and diffusion processes in such systems. Again, we study the relaxation kinetics towards equilibrium and discuss non-equilibrium states. We investigate the dynamics of droplets in the presence of reactions with broken detailed balance. Furthermore, we introduce active droplet systems maintained away from equilibrium via coupling to reservoirs at their boundaries and organizing reactions solely within droplets. Here, detailed balance is only broken at the boundaries. Nevertheless, stationary chemically active droplets exist in open systems, and droplets can divide. To quantitatively study chemically active droplet systems in multi-component mixtures, we introduce an effective description. Therefore, we couple linearized reaction-diffusion equations via a moving interface within a sharp interface limit. At the interface, the boundary conditions are set by a local phase equilibrium and the continuity of fluxes. Equipped with these tools, we introduce and study protocell models of chemically active droplets. We explicitly model these protocells’ nutrient and waste dynamics, leading to simple models of their metabolism. Next, we study the energetics of these droplets and identify processes responsible for growth or shrinkage and maintaining the system out of equilibrium. Furthermore, we discuss the energy balance leading to the heating and cooling of droplets. Finally, we show why chemically active droplets do not spontaneously divide in two-dimensional systems with bulk-driven reactions. Here, droplets can elongate but do not pinch off. To have a minimal two-dimensional model with droplet division, we introduce additional reactions. When these reactions are localized at the interface and dependent on its mean curvature, droplets robustly divide in 2D. In summary, this thesis contributes to the theoretical understanding of how the existence of droplets changes the kinetics of reactions and, vice versa, how chemical reactions can alter droplet dynamics.:1 Introduction 1.1 Thermodynamics of phase separation 1.1.1 Phase equilibrium in the thermodynamic limit 1.1.2 Relaxation dynamics towards equilibrium 1.1.3 Local stability of homogeneous phases 1.2 Thermodynamics of chemical reactions in homogenous mixtures 1.2.1 Conserved densities and reaction extents 1.2.2 Equilibrium of chemical reactions 1.2.3 Mass-action kinetics towards equilibrium 1.3 Simultaneous equilibrium of chemical reactions and phase separation 1.4 Chemical reactions maintained away from equilibrium 1.5 Structure of this thesis 2 Chemical reactions in compartmentalized systems 2.1 Mass-action kinetics for compartments built by phase separation 2.1.1 Dynamical equations for densities and phase volumes 2.1.2 Relaxation kinetics in a simple example 2.2 Driven chemical reactions in compartmentalized systems 2.2.1 Non-equilibrium steady states at phase equilibrium 2.2.2 The tie line selecting manifold 2.3 Discussion 3 Dynamics of concentration fields in phase-separating systems with chemical reactions 3.1 Reaction-diffusion equations for phase-separating systems 3.2 Relaxation towards thermodynamic equilibrium in spatial systems 3.2.1 Relaxation kinetics and fast diffusion 3.2.2 Relaxation kinetics with spatial gradients 3.3 Driven chemical reactions in phase-separating systems 3.3.1 Driven chemical reaction and fast diffusion 3.3.2 Non-equilibrium steady states and spatial gradients 3.3.3 Droplets growth and ripening with driven chemical reactions 3.4 Boundary-driven chemically active droplets 3.4.1 Droplets in open systems 3.4.2 Non-equilibrium steady droplets and shape instabilities 3.5 Discussion 4 Chemically active droplets in the sharp interface limit 4.1 Droplet dynamics via reaction-diffusion equations coupled by a moving interface 4.2 Stationary interface positions in spherical symmetry 4.2.1 Interface conditions in closed systems 4.2.2 Interface conditions in open systems 4.3 Shape instabilities of spherical droplets 4.4 Discussion 5 Models of protocells and their metabolism as chemically active droplets 5.1 Breaking detailed balance in protocell models 5.1.1 Boundary-driven protocell models 5.1.2 Bulk-driven protocell models 5.2 Protocell dynamics 5.2.1 Steady states droplets 5.2.2 Shape stability of spherical symmetric droplets 5.3 Energetics of protocells 5.3.1 Mass conservation and droplet growth or shrinkage 5.3.2 Energy conservation and droplet heating or cooling 5.4 Discussion 6 The role of dimensionality on droplet division 6.1 Stability of chemically active droplets in 2D vs. 3D 6.1.1 Stationary droplets in 1D, 2D and 3D 6.1.2 Elongation instability 6.1.3 Pinch-off instability 6.2 Pinch-off in 2D via curvature-dependent chemical reactions 6.2.1 Determining the mean curvature of the droplet interface 6.2.2 Chemical reactions at the interface 6.3 Discussion 7 Conclusion and Outlook A Free energy considerations B Surface tension in multi-component mixtures C Figure details Bibliograph

Individual choice in a residential building and heating model: An application case for Germany

In Germany and other Central and Northern European countries, energy demand for space heating dominates the energy demand of households. In line with European and national energy efficiency and emission reduction objectives, policy makers have identified the residential building sector potentials for the achieving of reduction targets. This paper presents an extended logit model approach for the residential heating market with special regard to the development of the built environment and the heating system choice. A policy as usual scenario for Germany is calculated as an application example to evaluate the likeliness of target achievement for the heating market, its energy demand and associated emissions

Relationships between ICT Use for Task and Social Functions, Work Characteristics, and Employee Task Proficiency and Job Satisfaction: Does Age Matter?

Digitalization and demographic change represent two megatrends that impact organizations and workplaces around the globe. Rapid developments in information and communication technology (ICT) are fundamentally changing the ways in which work is conducted. At the same time, workforces are becoming increasingly older and age diverse. Integrating the model of workplace ICT use and work design with socioemotional selectivity theory from the lifespan development literature, we investigate employee age as a moderator of the indirect and total effects of ICT use for task and social functions on self-rated task proficiency and job satisfaction. As potential mediators, we focus on three job-related resources: job autonomy, team cohesion, and task significance. Data were collected from 1761 employees at three measurement points across two months. The results showed that ICT use for task and social functions were not significantly associated with job autonomy, team cohesion, task significance, task proficiency, and job satisfaction, while controlling for baseline levels of these mediator and outcome variables. Job autonomy was negatively related to task proficiency, and team cohesion was positively related, whereas both job autonomy and team cohesion were positively related to job satisfaction. Contrary to expectations, age did not moderate the indirect and total effects of ICT use for task and social functions on task proficiency and job satisfaction. We discuss the implications of our findings for future research and practice regarding ICT use and age in the work context

DIGNIFIED DEATH IN BRAZIL

The present article seeks to argue about the history of death, the philosophical opinions on this phenomenon; to check whether euthanasia and assisted suicide would be probable motivators for the happening of the called slippery slope; whether orthothanasia would be a dignified way to die; to evaluate the concrete validity of the constitutional right to dignified death in the Brazilian juridical legislation and to examine the palliative care methods applied in this country, by using the deductive method of qualitative approach with bibliographic research technique on national e international references. It is concluded that may be found the traditional, the modern and the contemporary as ways of dying in Brazil.

Portuguese-Brazilian evidence-based guideline on the management of hyperglycemia in type 2 diabetes mellitus

Background: In current management of type 2 diabetes (T2DM), cardiovascular and renal prevention have become important targets to be achieved. In this context, a joint panel of four endocrinology societies from Brazil and Portugal was established to develop an evidence-based guideline for treatment of hyperglycemia in T2DM. Methods: MEDLINE (via PubMed) was searched for randomized clinical trials, meta-analyses, and observational studies related to diabetes treatment. When there was insufficient high-quality evidence, expert opinion was sought. Updated positions on treatment of T2DM patients with heart failure (HF), atherosclerotic CV disease (ASCVD), chronic kidney disease (CKD), and patients with no vascular complications were developed. The degree of recommendation and the level of evidence were determined using predefined criteria. Results and conclusions: In non-pregnant adults, the recommended HbA1c target is below 7%. Higher levels are recommended in frail older adults and patients at higher risk of hypoglycemia. Lifestyle modification is recommended at all phases of treatment. Metformin is the first choice when HbA1c is 6.5–7.5%. When HbA1c is 7.5–9.0%, dual therapy with metformin plus an SGLT2i and/or GLP-1RA (first-line antidiabetic agents, AD1) is recommended due to cardiovascular and renal benefits. If an AD1 is unaffordable, other antidiabetic drugs (AD) may be used. Triple or quadruple therapy should be considered when HbA1c remains above target. In patients with clinical or subclinical atherosclerosis, the combination of one AD1 plus metformin is the recommended first-line therapy to reduce cardiovascular events and improve blood glucose control. In stable heart failure with low ejection fraction ( 30 mL/min/1.73 m2, metformin plus an SGLT-2i is recommended to reduce cardiovascular mortality and heart failure hospitalizations and improve blood glucose control. In patients with diabetes-associated chronic kidney disease (CKD) (eGFR 30–60 mL/min/1.73 m2 or eGFR 30–90 mL/min/1.73 m2 with albuminuria > 30 mg/g), the combination of metformin and an SGLT2i is recommended to attenuate loss of renal function, reduce albuminuria and improve blood glucose control. In patients with severe renal failure, insulin-based therapy is recommended to improve blood glucose control. Alternatively, GLP-1RA, DPP4i, gliclazide MR and pioglitazone may be considered to reduce albuminuria. In conclusion, the current evidence supports individualizing anti-hyperglycemic treatment for T2DM

Energy and matter supply for active droplets

Chemically active droplets provide simple models for cell-like systems that can grow and divide. Such active droplet systems are driven away from thermodynamic equilibrium and turn over chemically, which corresponds to a simple metabolism. We consider two scenarios of non-equilibrium driving. First, droplets are driven via the system boundaries by external reservoirs that supply nutrient and remove waste (boundary-driven). Second, droplets are driven by a chemical energy provided by a fuel in the bulk (bulk-driven). For both scenarios, we discuss the conservation of energy and matter as well as the balance of entropy. We use conserved and non-conserved fields to analyze the non-equilibrium steady states of active droplets. Using an effective droplet model, we explore droplet stability and instabilities leading to droplet division. Our work reveals that droplet division occurs quite generally in active droplet systems. Our results suggest that life-like processes such as metabolism and division can emerge in simple non-equilibrium systems that combine the physics of phase separation and chemical reactions

The quality of information on maternal breast feeding and complementary feeding on Brazilian internet sites available for health professionals

OBJETIVOS: analisar as informações de sites da internet sobre o aleitamento materno e alimentação complementar de acordo com a adequação às recomendações do Ministério da Saúde do Brasil. MÉTODOS: realizado estudo transversal, com amostra de 103 sites de profissionais de saúde. Analisaram-se informações sobre aleitamento materno (AM) e alimentação complementar (AC). As informações foram quantificadas e analisadas qualitativamente. RESULTADOS: as recomendações relativas ao AM foram: exclusivo até 6º mês (64,1%); sem água e chá (31,1%); duração de dois anos ou mais (36,9%); e não utilizar mamadeira e chupeta (33%). Para a AC foi utilizada a terminologia desmame (30,1%), recomendada a introdução alimentar no 6º mês (47,9%), introdução da primeira papa com fruta (11,6%) ou suco (9,7%); e a oferta de sopa (14,6%) como refeição. Na análise qualitativa, entre as informações incorretas, constavam recomendações de consumo de carne no 12º mês, horários regulares para refeições, introdução de alimentos no 7º mês e consumo de leite de vaca no 6º mês. CONCLUSÕES: a maior parte das informações sobre aleitamento materno está de acordo com o preconizado pelo Ministério da Saúde, mas são insuficientes para estimular a prática do aleitamento materno. Já as informações sobre alimentação complementar na sua maioria divergem do recomendado.Objectives:to analyze the information available on internet sites regarding maternal breast feeding and complementary feeding according to the recommendations of the Brazilian Ministry of Health. Methods: a cross-sectional study was carried out using a sample of 103 sites for professional healthcare workers. Information was analyzed on maternal breast feeding (MB) and complementary feeding (CF). The information was quantified and analyzed qualitatively. Results: the recommendations for MB were: that it should be exclusive up to the 6th month of life (64.1%); that no water or tea should be added (31.1%); that it should last for two years or more (36.9%); and that bottles and/or pacifiers should not be used (33%). For CF, the term weaning was used (30.1%), it was recommended that solid feeding begin in the 6th month of life (47.9%), involving fruit pulp (11.6%) or juice (9.7%); and soup (14.6%). According to the qualitative analysis, incorrect information included recommending the consumption of meat in the 12th month of life, regular meals, the introduction of solid food in the 7th month and the consumption of cow’s milk in the 6th month. Conclusions: most of the information on breast feeding accords with the advice of the Brazilian Ministry of Health, but is not sufficient to encourage breast feeding. The information on complementary feeding mostly diverges from the official recommendations

Capacitação de Manipuladores de alimentos de serviços de alimentação

Anais do 35º Seminário de Extensão Universitária da Região Sul - Área temática: SaúdeO comércio ambulante de alimentos pode constituir um alto risco para a saúde dos consumidores, seja pela falta de estrutura física adequada, exposição dos alimentos a temperaturas inadequadas e manipuladores de alimentos não capacitados. Esses fatores podem influenciar diretamente na qualidade e segurança dos alimentos comercializados por estes estabelecimentos. Desta forma o presente projeto de extensão tem como objetivo capacitar os fiscais e agentes da Vigilância Sanitária e o comércio ambulante de alimentos e bebidas de um festival nativista da região noroeste do estado do Rio Grande do Sul e verificar as condições higiênicas, por meio de uma lista de verificação em boas práticas. As capacitações para os agentes da Vigilância Sanitária foram ministradas nos anos de 2015, 2016 e 2017 em todos os anos antes do início do festival. Participaram da capacitação 90 estabelecimentos ambulantes de alimentos, sendo que os mesmos obtiveram baixo percentual de adequação conforme resultados da lista de verificação. Desta forma a realização de capacitações para o comercio ambulante de alimentos e bebidas visou incentivar as adequações dos estabelecimentos segundo as legislações sanitárias vigente

A associação do desenho da figura humana com personalidade e problemas de comportamento em crianças

O Desenho da Figura Humana (DFH) é uma técnica gráfica com ampla aceitação em vários países do mundo. No Brasil, especialmente, é um teste psicológico muito utilizado pelos profissionais da Psicologia, em diferentes contextos. Além de permitir a avaliação do funcionamento cognitivo, estudos demonstram que o DFH possibilita a detecção de aspectos emocionais infantis. Dessa maneira, o Estudo 1 teve como objetivo verificar a associação entre índices do DFH e personalidade. Participaram do estudo 296 crianças, com idades entre 5 e 10 anos. Os participantes foram classificados em três perfis distintos de personalidade, de acordo com suas pontuações na Escala de Traços de Personalidade para Criancas (ETPC). O Estudo 2, por sua vez, buscou a identificação de indicadores emocionais nos desenhos de 163 crianças, com idades entre 6 e 12 anos. Os participantes foram classificados em grupos clínico e não clínico, de acordo com a amostra normativa do Child Behavior Checklist (CBCL 6/18), o qual foi preenchido pelos pais e/ou cuidadores. O teste Matrizes Progressivas Coloridas de Raven foi utilizado em ambos os estudos para excluir os participantes com classificação deficiente. Todos os desenhos foram pontuados com base em uma lista de 114 indicadores emocionais encontrados na literatura sobre o tema, abrangendo autores como Machover, Koppitz, Buck e Naglieri. As análises estatísticas foram realizadas de acordo com o sexo da criança, portanto os resultados são diferentes para meninos e meninas. Inicialmente, foram levantados 30 desenhos para verificar a concordância entre as pontuações. Após a discussão dos pontos divergentes, a realização de um novo treinamento e a verificação da existência de concordância, cada uma das juízas procedeu as análises de maneira individual. Através desse estudo, foi possível a associação entre alguns itens do DFH e personalidade em crianças. O DFH também mostrou-se uma ferramenta de triagem importante na avaliação de problemas de comportamento infantil, em especial do tipo internalizante.The Draw-A-Person test (DAP) is a graphic technique with a large acceptance in many countries. In Brazil, mainly, it is a psychological test frequently used by the psychologysts, in different contexts. In addition to permit the cognitive assessment, studies evidence that DAP enables the evaluation of emotional aspects in children. Thus, Study 1 set out to explore the association between DAP items and personality. The study sample consisted of 296 children, aged between 5-10 years old. The participants were classified in three personality clusters, according to their score at the Children Personality Traits Scale. On the other hand, Study 2 aimed the assessment of emotional indicators in the drawings of 163 children, aged between 6-12 years old. The participants were classified in clinical and non-clinical groups, according to the Child Behavior Checklist (CBCL 6/18). The Raven Progressive Matrices was used in both studies to exclude those participants with deficient classification. All the drawings were scored based on a list of 114 emotional indicators, which were found at the literature about DAP, based on authors as Machover, Koppitz, Buck and Naglieri. The statistical analysis was done according to the sex of the chid, therefore the results are different for boys and girls. The drawing analyses were made by three independent judges, trained by the author of this research. Firstly, 30 drawings were evaluated to verify the agreement between the ratings. After the discussion about the divergent aspects, the realization of a new training and the new agreement between judges, each judge continued the analysis individually. Through this research, it was possible the association between some DAP items and personality in children. DAP also showed to be an important screening tool in children`s emotional problems evaluation, specially the internalizing type