Search

Há uma lacuna de estudos empíricos acerca dos incentivos econômicos e modelos de financiamento das indústrias e iniciativas de desinformação no Brasil. O objetivo deste artigo é oferecer uma análise das publicidades programáticas que são exibidas em matérias do website de extrema-direta Terra Brasil Notícias. Para isso, desenvolvemos um script de raspagem de dados de anúncios nativos da empresa MGID, compondo uma base de dados de 27.602 inserções durante um mês. Encontramos uma rede de fazenda de conteúdos e anúncios contendo vírus, casas de apostas, fraudes financeiras e compostos milagrosos para redução de peso corporal. Ao final do artigo, debatemos as contribuições com a literatura sobre desinformação e apontamos caminhos para estudos futuros.

Contrary to the methane steam reforming process, the methane thermal cracking route forms only hydrogen and solid carbon throughout the process. The generated hydrogen has a high degree of purity, and the solid carbon can be commercialized for other industrial purposes. This work seeks to thermodynamically characterize the thermal cracking reaction of methane to maximize the formation of hydrogen, minimize the impacts caused by the formation of coke throughout the process and discuss the possibility of using part of the generated hydrogen as a source of energy for the development of the process. Methodologies based on Gibbs energy minimization and entropy maximization are used, simulating operating conditions of isothermal and adiabatic reactors, respectively. The combined chemical and phase equilibrium problems were solved in the software GAMS version 23.9.5, with the aid of the solver CONOPT3. High temperatures and low pressures favour the decomposition of methane into hydrogen as expected due to the stoichiometry of the reaction and its endothermic effect. When conditioned to adiabatic reactors, the addition of hydrogen along with methane in the feed stream tends to maximize methane decomposition, minimizing the endothermic effect of the process. Setting the CH4/H2 ratio at 1:10 in the process feed at 1600 K, varying the system pressure from 50 to 1 bar, the methane conversion varies from 0 to 94.62 %, thus indicating the possibility of promoting the reaction by the effect of depressurization, which can be promoted by an isentropic valve. Keeping the CH4/H2 ratio at 1:6 at 1300 K and 50 bar, recycling part of the methane generated and using part of the hydrogen to generate energy for the process to occur, about 66% of the product stream is composed of hydrogen generated after the depressurization to 1 bar and of this total, approximately 38% would be destined to generate energy for the occurrence of the process, being this the optimal theoretical operational condition for this process.

Lung cancer is the second leading cause of cancer death worldwide and is strongly associated with cisplatin resistance. The transcription factor signal transducer and activator of transcription 3 (STAT3) is constitutively activated in cancer cells and coordinates critical cellular processes as survival, self-renewal, and inflammation. In several types of cancer, STAT3 controls the development, immunogenicity, and malignant behavior of tumor cells while it dictates the responsiveness to radio- and chemotherapy. It is known that STAT3 phosphorylation at Ser727 by mechanistic target of rapamycin (mTOR) is necessary for its maximal activation, but the crosstalk between STAT3 and mTOR signaling in cisplatin resistance remains elusive. In this study, using a proteomic approach, we revealed important targets and signaling pathways altered in cisplatin-resistant A549 lung adenocarcinoma cells. STAT3 had increased expression in a resistance context, which can be associated with a poor prognosis. STAT3 knockout (SKO) resulted in a decreased mesenchymal phenotype in A549 cells, observed by clonogenic potential and by the expression of epithelial-mesenchymal transition markers. Importantly, SKO cells did not acquire the mTOR pathway overactivation induced by cisplatin resistance. Consistently, SKO cells were more responsive to mTOR inhibition by rapamycin and presented impairment of the feedback activation loop in Akt. Therefore, rapamycin was even more potent in inhibiting the clonogenic potential in SKO cells and sensitized to cisplatin treatment. Mechanistically, STAT3 partially coordinated the cisplatin resistance phenotype via the mTOR pathway in non-small cell lung cancer. Thus, our findings reveal important targets and highlight the significance of the crosstalk between STAT3 and mTOR signaling in cisplatin resistance. The synergic inhibition of STAT3 and mTOR potentially unveil a potential mechanism of synthetic lethality to be explored for human lung cancer treatment.

Nesta investigação apresentamos os resultados de como a colaboração favorece o desenvolvimento profissional de um grupo de professoras dos anos iniciais de uma escola pública que se propuseram a implementar a alfabetização científica em suas aulas. As docentes se reuniram virtualmente em função da pandemia com o objetivo de discutir e propor soluções para trabalharem a alfabetização científica. Neste processo, emergiram questões que se relacionavam com a sua formação inicial, sua identidade profissional e a suas respectivas práticas pedagógicas, entre outros aspectos. O grupo colaborativo mostrou-se efetivo para fomentar novas aprendizagens e visões fundamentais para o processo de desenvolvimento profissional. Tentou-se localizar quais elementos deste processo forma mais valorizados pelas professoras. Neste sentido utilizamos um modelo analítico que relaciona o desenvolvimento profissional com reflexões alinhadas a oito contextos formativos que, por sua vez, dialogam com a academia, a escola e a sociedade. Nossos achados apontam que tais reflexões foram favorecidas em função do engajamento das professoras na cultura colaborativa.

Covering: 2019 to 2023. Even with the advent of modern and complementary spectroscopy techniques, comprehensive characterization of natural product continues to represent an onerous and time-consuming task, being far away to become rather "routine". Mainly due to their highly complex structures and small amount of isolated sample, in milligram or sub-milligram quantities, structural misassignment of natural products are still a recurrence theme in the modern literature. Since the seminal paper from Nicolau and Snider, in 2005, evaluating the various cases of reassignment of natural products, from the present era, in which NMR parameters calculations play such an important role in the structural elucidation of natural products, helping to uncover and ultimately revise the structure of previously reported compounds, a pertinent question arises: are we still chasing molecules that were never there? In this minireview, we intent to discuss the current state of computational NMR parameter calculations, with a particular focus on their application in the structural determination of natural products. Additionally, we have conducted a comprehensive survey of the literature spanning the years 2019-2023, in order to select and discuss recent noteworthy cases of incorrectly assigned structures that were revised through NMR calculations. Therefore, our main goal is to show what can be done through computational simulations of NMR parameters, currently user-friendly and easily implemented by non-expert users with basic skills in computational chemistry, before venturing into complex and time-consuming total synthesis projects. In conclusion, we anticipate a promising future for NMR parameter calculations, fueled by the ongoing development of user-friendly tools and the integration of artificial intelligence. The emergence of these advancements is poised to broaden the applications of NMR simulations, offering a more accessible and reliable means to address the persistent challenge of structural misassignments in natural product chemistry. [ABSTRACT FROM AUTHOR]

Brazil is one of the most biodiverse countries in the world, with a coastline that stretches over 7,000 km including various marine ecosystems, such as coral reefs, mangroves, and seagrass beds, among other habitats. These diverse environments provide a rich source of compounds, derived from primary or secondary metabolism, which may have countless biological activities. Research onmarine natural products (MNP) in Brazil has been ongoing for several decades and led to the discovery of numerous bioactive compounds with potential applications in medicine, agriculture, and cosmetics. These MNP are structurally complex, both from an architectural and stereochemical point of view. However, even with all the well-established techniques for the absolute configuration (AC) assignment, this stage of structural characterization of natural products is still under-explored and remains a challenge. This review presents an overview of natural product chemistry in Brazil, focusing on the stereochemical assignment of marine chiral compounds. The main goals are to describe the techniques employed in the assignments as well as to highlight the importance of choosing the appropriate methods for chiral natural products AC determinations. [ABSTRACT FROM AUTHOR]

No Estado do Rio Grande do Norte encontram-se falésias constituídas por sedimentos da Formação Barreiras sobre os quais se desenvolvem cidades e obras de infraestrutura. Nesta região são relatados, movimentos de massa, em proporções relevantes, principalmente em períodos de chuva. O objetivo deste trabalho foi estudar as propriedades geotécnicas dos solos da Formação Barreiras que compõem a falésia da praia da Barra de Tabatinga/RN. A falésia estudada foi dividida em três solos predominantes, os quais estão localizados na camada de base (AM-01), meio (AM-02) e topo (AM-03). Nesses solos, foram realizados ensaios de caracterização (geotécnica, química e mineralógica), ensaios para determinação da curva de retenção, ensaios de permeabilidade, compressão triaxial e diametral nas condições saturada e não saturada. As amostras AM-01 e AM-02 apresentaram curvas de retenção bimodais, diferentemente da amostra do topo, que apresentou formato unimodal. Além disso, todas elas apresentaram coesão próxima de zero e ângulo de atrito em torno de 30° na condição saturada. No entanto, quando não saturadas, os parâmetros de resistência aumentaram consideravelmente, apresentando diferenças significativas entre as amostras. A resistência a tração diminuiu com o aumento do grau de saturação chegando a atingir valores desprezíveis em todos os solos quando saturadas. O solo do topo é o mais permeável dos solos estudados, apresentando coeficiente de permeabilidade compatível com uma areia pura.

OBJECTIVES: This observational, cross-sectional study based aimed to test whether heart failure (HF)-disease management program (DMP) components are influencing care and clinical decision-making in Brazil. METHODS: The survey respondents were cardiologists recommended by experts in the field and invited to participate in the survey via printed form or email. The survey consisted of 29 questions addressing site demographics, public versus private infrastructure, HF baseline data of patients, clinical management of HF, performance indicators, and perceptions about HF treatment. RESULTS: Data were obtained from 98 centers (58% public and 42% private practice) distributed across Brazil. Public HF-DMPs compared to private HF-DMP were associated with a higher percentage of HF-DMP-dedicated services (79% vs 24%; OR: 12, 95% CI: 94-34), multidisciplinary HF (MHF)-DMP [84% vs 65%; OR: 3; 95% CI: 1-8), HF educational programs (49% vs 18%; OR: 4; 95% CI: 1-2), written instructions before hospital discharge (83% vs 76%; OR: 1; 95% CI: 0-5), rehabilitation (69% vs 39%; OR: 3; 95% CI: 1-9), monitoring (44% vs 29%; OR: 2; 95% CI: 1-5), guideline-directed medical therapy-HF use (94% vs 85%; OR: 3; 95% CI: 0-15), and less B-type natriuretic peptide (BNP) dosage (73% vs 88%; OR: 3; 95% CI: 1-9), and key performance indicators (37% vs 60%; OR: 3; 95% CI: 1-7). In comparison to non- MHF-DMP, MHF-DMP was associated with more educational initiatives (42% vs 6%; OR: 12; 95% CI: 1-97), written instructions (83% vs 68%; OR: 2: 95% CI: 1-7), rehabilitation (69% vs 17%; OR: 11; 95% CI: 3-44), monitoring (47% vs 6%; OR: 14; 95% CI: 2-115), GDMT-HF (92% vs 83%; OR: 3; 95% CI: 0-15). In addition, there were less use of BNP as a biomarker (70% vs 84%; OR: 2; 95% CI: 1-8) and key performance indicators (35% vs 51%; OR: 2; 95% CI: 91,6) in the non-MHF group. Physicians considered changing or introducing new medications mostly when patients were hospitalized or when observing worsening disease and/or symptoms. Adherence to drug treatment and non-drug treatment factors were the greatest medical problems associated with HF treatment. CONCLUSION: HF-DMPs are highly heterogeneous. New strategies for HF care should consider the present study highlights and clinical decision-making processes to improve HF patient care.

We document for the first time three predation events notoriously hard to come by in the Caatinga biome in Brazil: Philodryas nattereri by preying on a specimen of Leptodactylus sp.; the predation of Tropidurus hispidus by the spider Iridopelma katiae; and the predation of Gymnodactylus geckoides by T. hispidus. Although these are basic records, the descriptions of the predation events contribute to the knowledge of the diet of different species of herpetofauna in a Brazilian biome that is threatened by accelerated deforestation. [ABSTRACT FROM AUTHOR]

Predation events are difficult to observe due to the unpredictable nature of the environment and timing, which may result in researchers and observers being unable to document them or having to leave before the event is completed. Here, we present predation attempts on Crotophaga major and Thraupis palmarum by Oxybelis fulgidus. These events provide important aspects that contribute to our understanding of the interspecific relationships between predator and prey that can be observed. In addition, we present C. major and T. palmarum as potencial novel food items in the diet of O. fulgidus. [ABSTRACT FROM AUTHOR]