CIRURGIA BARIÁTRICA: INDICAÇÕES E TÉCNICAS CIRÚRGICAS

Obesity is a complex global health issue that demands an integrated approach. Understanding its epidemiology, risk factors, progression, early diagnosis, and social and economic implications is crucial to addressing this growing challenge. Bariatric surgery in the adult population is a dynamic and intricate field where techniques, indications, contraindications, complications, and historical evolution intricately intertwine. The examined literature reveals a continuous need for personalized and multidisciplinary approaches, considering not only the physical but also the psychological and social aspects of patients undergoing this intervention. Surgical techniques in addressing obesity have specificities that should be carefully evaluated by healthcare professionals. The reviewed literature provides valuable insights to support clinical decisions, highlighting the benefits and specific considerations associated with adjustable gastric banding, vertical gastrectomy, and gastric bypass. The significance of the multidisciplinary team in bariatric surgery lies in the comprehensive approach to the patient, addressing various medical, nutritional, psychological, and social aspects involved. This collaborative approach is essential to ensure successful outcomes, patient satisfaction, and the prevention of short- and long-term complications.A obesidade é um problema de saúde global complexo que exige uma abordagem integrada. A compreensão de sua epidemiologia, fatores de risco, evolução, diagnóstico precoce e implicações sociais e econômicas é crucial para enfrentar esse desafio crescente. a cirurgia bariátrica na população adulta é um campo dinâmico e complexo, onde as técnicas, indicações, contraindicações, complicações e a evolução histórica se entrelaçam de maneira intrincada. A literatura examinada revela a necessidade contínua de abordagens personalizadas e multidisciplinares, considerando não apenas os aspectos físicos, mas também os psicológicos e sociais dos pacientes submetidos a essa intervenção. as técnicas cirúrgicas na abordagem da obesidade apresentam particularidades que devem ser cuidadosamente avaliadas pelos profissionais de saúde. A literatura revisada fornece subsídios valiosos para embasar decisões clínicas, evidenciando os benefícios e as considerações específicas associadas à banda gástrica ajustável, à gastrectomia vertical e ao bypass gástrico. A importância da equipe multidisciplinar na cirurgia bariátrica reside na abordagem integral do paciente, contemplando os diversos aspectos médicos, nutricionais, psicológicos e sociais envolvidos. Essa abordagem colaborativa é essencial para garantir resultados bem-sucedidos, a satisfação do paciente e a prevenção de complicações a curto e longo prazo

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

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

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

Obtenção de camadas de difusão gasosa para célula a combustível do tipo PEM utilizando fibras curtas de carbono foto-funcionalizadas por luz UV

As células a combustível do tipo PEMFC necessitam de alta durabilidade, eficiência e custo baixo de produção para que tenham aplicação prática. Um dos componentes da célula denominado MEA (Membrane Electrode Assembly) é composto por uma membrana trocadora de prótons e por camadas de difusão gasosa (CDG) que devem ser altamente condutores, porosos e hidrofóbicos. CDGs com alta hidrofobicidade são geralmente preparadas com revestimentos à base de Nafion® e PTFE (politetrafluoretileno) sobre a superfície do substrato (polímero reforçado com fibra/papel de carbono). No entanto, alguns estudos têm demonstrado que o desempenho das CDG’s tende a diminuir com o aumento de PTFE na superfície. O presente trabalho apresenta um método de tratamento superficial através de modificação assistida por radiação UV na presença do agente hidrofóbico Trimetóxipropilsilano (TMPSi). Foram realizadas modificações superficiais inserindo grupos hidrofóbicos na superfície da CDG por meio da imersão da mesma em H2O2 10% por 2 minutos, seguida da irradiação (254 nm) na presença de TMPSi por 60 e 120 min. Aplicou-se também um tratamento térmico a 80 °C por 120 minutos após a irradiação. As amostras foram caracterizadas quanto à molhabilidade por monitoramento do ângulo de contato (WCA - water contact angle), que evidenciou um aumento de aproximadamente 30° no WCA para as amostras. Análises de FTIR-ATR evidenciaram a evolução das ligações químicas realizadas na superfície do polímero e medidas de condutividade elétrica mostraram que houve um decréscimo menor com o tratamento superficial por foto-funcionalização hidrofóbica do que com os tratamentos a base de PTFE. Os resultados evidenciaram a eficiência do tratamento proposto para a produção de CDGs hidrofóbicas em alternativa aos tratamentos convencionais com PTFE e a um custo reduzido.The PEMFC type fuel cell requires high durability, efficiency and low production cost to achieve wide-spread practical application. One of the components of the cell, called MEA (Membrane Electrode Assembly), comprises a proton exchange membrane and gas diffusion electrodes (GDL) that must be highly conductive, porous and hydrophobic. The highly hydrophobic GDL are usually prepared with coatings based on PTFE (polytetrafluoroethylene) on the surface of the substrate (fiber reinforced polymer/carbon paper), even though some studies have shown that the performance of CDG's tends to decrease with increasing PTFE surface. This work focuses on a surface treatment method assisted by UV radiation in the presence of a hydrophobic agent (trimetoxipropylsilane - TMPSi). Surface modifications were carried out by inserting hydrophobic groups on the surface of CDG by its immersion on 10% H2O2 solution for 2 min, followed by irradiation (254 nm) in the presence of TMPSi for 60 and 120 min. A heat treatment, 80 °C for 120 min, was also applied after irradiation. The samples were characterized, among others, by WCA (water contact angle) which showed an increase of nearly 30°, whereas FTIR-ATR showed change in chemical bonds on the polymer surface. Conductivity measurements showed higher values with the hydrophobic photo-functionalization surface treatment than the treatments based on PTFE. The results evidenced the effectiveness of the proposed treatment for the production of hydrophobic CDGs as an alternative to conventional PTFE treatments and at low cost

Obtenção de camadas de difusão gasosa para célula a combustível do tipo PEM utilizando fibras curtas de carbono foto-funcionalizadas por luz UV

As células a combustível do tipo PEMFC necessitam de alta durabilidade, eficiência e custo baixo de produção para que tenham aplicação prática. Um dos componentes da célula denominado MEA (Membrane Electrode Assembly) é composto por uma membrana trocadora de prótons e por camadas de difusão gasosa (CDG) que devem ser altamente condutores, porosos e hidrofóbicos. CDGs com alta hidrofobicidade são geralmente preparadas com revestimentos à base de Nafion® e PTFE (politetrafluoretileno) sobre a superfície do substrato (polímero reforçado com fibra/papel de carbono). No entanto, alguns estudos têm demonstrado que o desempenho das CDG’s tende a diminuir com o aumento de PTFE na superfície. O presente trabalho apresenta um método de tratamento superficial através de modificação assistida por radiação UV na presença do agente hidrofóbico Trimetóxipropilsilano (TMPSi). Foram realizadas modificações superficiais inserindo grupos hidrofóbicos na superfície da CDG por meio da imersão da mesma em H2O2 10% por 2 minutos, seguida da irradiação (254 nm) na presença de TMPSi por 60 e 120 min. Aplicou-se também um tratamento térmico a 80 °C por 120 minutos após a irradiação. As amostras foram caracterizadas quanto à molhabilidade por monitoramento do ângulo de contato (WCA - water contact angle), que evidenciou um aumento de aproximadamente 30° no WCA para as amostras. Análises de FTIR-ATR evidenciaram a evolução das ligações químicas realizadas na superfície do polímero e medidas de condutividade elétrica mostraram que houve um decréscimo menor com o tratamento superficial por foto-funcionalização hidrofóbica do que com os tratamentos a base de PTFE. Os resultados evidenciaram a eficiência do tratamento proposto para a produção de CDGs hidrofóbicas em alternativa aos tratamentos convencionais com PTFE e a um custo reduzido.The PEMFC type fuel cell requires high durability, efficiency and low production cost to achieve wide-spread practical application. One of the components of the cell, called MEA (Membrane Electrode Assembly), comprises a proton exchange membrane and gas diffusion electrodes (GDL) that must be highly conductive, porous and hydrophobic. The highly hydrophobic GDL are usually prepared with coatings based on PTFE (polytetrafluoroethylene) on the surface of the substrate (fiber reinforced polymer/carbon paper), even though some studies have shown that the performance of CDG's tends to decrease with increasing PTFE surface. This work focuses on a surface treatment method assisted by UV radiation in the presence of a hydrophobic agent (trimetoxipropylsilane - TMPSi). Surface modifications were carried out by inserting hydrophobic groups on the surface of CDG by its immersion on 10% H2O2 solution for 2 min, followed by irradiation (254 nm) in the presence of TMPSi for 60 and 120 min. A heat treatment, 80 °C for 120 min, was also applied after irradiation. The samples were characterized, among others, by WCA (water contact angle) which showed an increase of nearly 30°, whereas FTIR-ATR showed change in chemical bonds on the polymer surface. Conductivity measurements showed higher values with the hydrophobic photo-functionalization surface treatment than the treatments based on PTFE. The results evidenced the effectiveness of the proposed treatment for the production of hydrophobic CDGs as an alternative to conventional PTFE treatments and at low cost

Modelagem experimental e num?rica da geoqu?mica do sistema CO2-Fluido-Rocha em reservat?rios carbon?ticos no contexto do armazenamento de carbono e recupera??o avan?ada de petr?leo

Submitted by PPG Engenharia e Tecnologia de Materiais ([email protected]) on 2019-01-10T19:28:50Z No. of bitstreams: 1 Tese_DOUTORADO_TiagoSiqueira2018.pdf: 9579783 bytes, checksum: d08e2b4f354be642a971f019a41d8dda (MD5)Approved for entry into archive by Caroline Xavier ([email protected]) on 2019-01-16T15:39:14Z (GMT) No. of bitstreams: 1 Tese_DOUTORADO_TiagoSiqueira2018.pdf: 9579783 bytes, checksum: d08e2b4f354be642a971f019a41d8dda (MD5)Made available in DSpace on 2019-01-16T15:46:08Z (GMT). No. of bitstreams: 1 Tese_DOUTORADO_TiagoSiqueira2018.pdf: 9579783 bytes, checksum: d08e2b4f354be642a971f019a41d8dda (MD5) Previous issue date: 2018-01-26Carbon dioxide capture and storage in geological formations is an interesting technological solution for avoiding the emission of greenhouse gases from large industrial sources to the atmosphere. Also, it is largely employed in the oil & gas exploration industry, for enhanced oil recovery (EOR) operations. It is a known fact that injection of massive amounts of CO2 into geological reservoirs may lead to a series of alterations due to chemical and physical interactions with the fluid and minerals of the reservoir formation. Experimental and numerical models have been employed in many studies in the past decades, in order to investigate these effects on the geological environment. So far, most of these studies were focused in siliciclastic formations, whereas carbonate reservoirs, which are known to be much more chemically reactive when interacting with CO2, were less investigated. In this study, experiments were performed with rocks of carbonate composition found in typical oil and gas reservoirs with the purpose of evaluating the changes resulting from CO2-fluid-rock interactions under geological carbon storage conditions.A captura e armazenamento de di?xido de CO2 atrav?s da inje??o em forma??es geol?gicas ? uma solu??o tecnol?gica v?lida para evitar a emiss?o de gases de efeito estufa para a atmosfera a partir de grandes fontes industriais. Al?m disso, ? amplamente utilizada na ind?stria de explora??o de petr?leo e g?s, associada ? recupera??o avan?ada de petr?leo (EOR). ? fato conhecido que a inje??o de grandes quantidades de CO2 em reservat?rios geol?gicos pode conduzir a uma s?rie de altera??es devido a intera??es qu?micas e f?sicas com o fluido e os minerais da forma??o do reservat?rio. Modelos experimentais e num?ricos foram empregados em v?rios estudos nas ?ltimas d?cadas, a fim de investigar estes efeitos sobre o ambiente geol?gico. At? agora, a maior parte destes estudos foram focados em forma??es silicicl?sticas, ao passo que os reservat?rios de carbonato, que s?o conhecidos por serem muito mais reativos quimicamente quando interagindo com CO2, foram muito menos investigados. Neste estudo, foram realizados experimentos com rochas de composi??o similar aos carbonatos encontrados nos reservat?rios de ?leo e g?s com o intuito de avaliar as mudan?as decorrentes das intera??es CO2-fluido-rocha em condi??es de armazenamento de carbono em escala de reservat?rio