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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.

Este trabalho apresenta a caracterização geotécnica e as propriedades de compressibilidade do solo residual da Formação Potengi presente na cidade de Natal-RN. Foram executados ensaios de caracterização geotécnica e de compressão unidimensional confinada. Os ensaios de compressão confinada foram realizados na umidade natural, na condição saturada, em uma amostra amolgada preparada com o teor de umidade próximo do Limite de Liquidez e em uma amostra compactada com a energia do Proctor Normal. Foram ainda realizados ensaios inundados em vários estágios de carregamento com vistas a analisar a colapsibilidade do solo. Os resultados mostraram que o solo sofre colapso devido a inundação para os níveis de tensões ensaiados. Verificou-se ainda que as deformações de colapso aumentam com o aumento da tensão de compressão na qual o solo foi inundado, não tendo sido caracterizado uma deformação de colapso máximo.

The fungus Moniliophthora perniciosa is the causal agent of the witches’ broom disease of cacao (Theobroma cacao). This fungus has a pyrophosphorylase enzyme to catalyze the formation of UDP-N-acetylglucosamine-1-phosphate, an intermediate in the biosynthesis of the fungal cell wall. This enzyme was studied by QM/MM methods to understand its catalytic mechanism. Initially, the structure was refined and submitted to molecular dynamics simulations. Next, QM/MM calculations were used to scan the coordinates of the reaction from the reactants to products; an SN2 mechanism has been proposed of the aforementioned reaction. In this system, the nucleophile is the oxygen atom of the phosphate group from N-acetylglucosamine-1-phosphate. It attacks the phosphorus of the alfa-phosphate from the uridine triphosphate to form UDP-N-acetylglucosamine and pyrophosphate. The calculated reaction was exothermic (ΔH = -81.01 Kcal/mol). On the reaction pathway, the most energetic structure had the phosphorus atom attacked in a pentacoordinate configuration. This structure interacts with the catalytic site composed by the residues Gly112, Gly113, Arg116, Lys123 and Gly225 through hydrogen bonds. During the mechanism study, the geometry of the transition state was obtained. Thus, the generation of new compounds sharing a geometric similarity with this pentacoordinate transition state can lead to the development of more active compounds possessing antifungal proprieties against witch's broom. DOI: http://dx.doi.org/10.17807/orbital.v7i3.629

Brazil has the second-highest COVID-19 death rate worldwide, and Rio de Janeiro is among the states with the highest rate in the country. Although vaccine coverage has been achieved, it is anticipated that COVID-19 will transition into an endemic disease. It is concerning that the molecular mechanisms underlying clinical evolution from mild to severe disease, as well as the mechanisms leading to long COVID-19, are not yet fully understood. NMR and MS-based metabolomics were used to identify metabolites associated with COVID-19 pathophysiology and disease outcome. Severe COVID-19 cases (n = 35) were enrolled in two reference centers in Rio de Janeiro within 72 h of ICU admission, alongside 12 non-infected control subjects. COVID-19 patients were grouped into survivors (n = 18) and non-survivors (n = 17). Choline-related metabolites, serine, glycine, and betaine, were reduced in severe COVID-19, indicating dysregulation in methyl donors. Non-survivors had higher levels of creatine/creatinine, 4-hydroxyproline, gluconic acid, and N-acetylserine, indicating liver and kidney dysfunction. Several changes were greater in women; thus, patients' sex should be considered in pandemic surveillance to achieve better disease stratification and improve outcomes. These metabolic alterations may be useful to monitor organ (dys) function and to understand the pathophysiology of acute and possibly post-acute COVID-19 syndromes. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to determine whether performing bedside ultrasound impacts the occurrence of acute kidney injury (AKI) in the immediate postoperative period (POP) of high-risk surgery patients. Methods: POP patients were randomly assigned to two groups: (i) ultrasound (US) group, in which hemodynamic management was guided with clinical parameters supplemented with the bedside US findings; (ii) control group, hemodynamic management based solely on clinical parameters. Two exams were performed in the first 24 h of admission. Results: Fifty-one patients were randomized to the US group and 60 to the control group. There was no significant difference for incidence of AKI in both groups assessed 12 h (31.4% vs 35.0%, P = 0.84), 24 h (27.5% vs 23.3%, P = 0.66), or 7 days (17.6 vs 8.3%, P = 0.16) after surgery. No difference was found in the amounts of volume administered over the first 12 h (1000 [500–2000] vs. 1000 [500–1500], P = 0.72) and 24 h (1000 [0–1500] vs. 1000 [0–1500], P = 0.95) between the groups. Patients without AKI in the control group received higher amounts of volume during the ICU stay. Conclusion: The use of bedside US in the immediate postoperative period of high-risk surgery did not show benefits in reducing AKI incidence. [ABSTRACT FROM AUTHOR]

O uso das tecnologias na Educação Matemática apresenta uma abordagem na busca por uma Matemática significativa e relacionada à realidade do aluno, possibilitando a construção do conhecimento, a comunicação matemática e a resolução de problemas. Aplicativos computacionais educacionais surgiram oportunizando aos alunos a aplicação dos conceitos matemáticos bem como aproximações com linguagens de programação. Um exemplo destes aplicativos é o Scratch. O presente artigo traz uma compilação bibliográfica com objetivo de auxiliar professores no entendimento da ferramenta Scratch e suas finalidades, bem como identificar diferentes conteúdos que podem ser trabalhados em sala de aula por meio dela como atividade prática, considerando os anos finais do Ensino Fundamental e os Conteúdos Estruturantes dispostos nas Diretrizes Curriculares Estaduais do Estado do Paraná. Para a concretização deste estudo, foi realizado um levantamento dos conteúdos matemáticos a serem trabalhados nos anos finais do Ensino Fundamental, bem como a identificação de quais conteúdos podem ser ensinados através do Scratch. Percebeu-se que o Scratch é uma importante ferramenta que pode ser amplamente explorada no processo de ensino e aprendizagem da Matemática, entretanto é importante que haja um entendimento a respeito dos conteúdos e das formas de aplicação prática no software.

This study presents an innovative and original biomaterial designed to substitute for articular cartilage and mimic its mechanical behavior, including elastic cushioning and the characteristics of fiber-reinforced gel. The material was composed of polyurethane and bioglass microfiber 45S5. It was designed to present a tribological surface to the cartilage of the tibial plateau, and to convert over a functional gradient to an osteointegrable region for self-anchorage to the subchondral bone. The biomaterial samples showed no toxicity and promoted cell spreading. Subsequent in vivo studies in rabbits demonstrated the formation of a rigid structure similar to bone trabeculae in the distal region of the tribological surface of the implant. The tribological surface of the proximal region showed a fibrocartilaginous tissue with highly vascularized chondrocytes, thus validating the proposed concept for the design of the implant incorporating a functional gradient and auto-stability.

This paper proposes a modification in both topology and operation algorithm for the existent 2/3 level converter. The modified strategy is of simple implementation. In addition, the modified topology reduces the switching losses and the command complexity. The harmonic distortion and losses of the two- level converter, the three-level Neutral-Point-Clamped (NPC) converter and the 2/3-level converter are compared. Also the limitation of the modified topology operation is investigated. Simulated and experimental results demonstrate the validity of the proposed topology and pulsewidth modulation method.

Introduction Panstrongylus megistus is commonly found in wild environments of the State of Rio Grande do Sul, Brazil. The aim of this study was to characterize the network of refuges used by triatomine in a forest fragment of Porto Alegre and to identify Trypanosoma cruzi infection, associated hosts and the epidemiological importance of both hosts and triatomines. Methods Techniques including the spool-and-line method and active searching (transects) were used to identify natural foci. Results The food source for each triatomine was determined using the precipitin test, and the infection of marsupials was determined by xenodiagnosis. A total of 33 adults (domestic environment) and 27 nymphs (wild environment) of P. megistus were found in addition to 43 Didelphis albiventris specimens. The infection rates of triatomine adults, triatomine nymphs and opossums with T. cruzi I were 64%, 73% and 69%, respectively. Birds, rodents and opossums were the main resources used by triatomine. Conclusions This work presents the first characterization of a natural focus of P. megistus in Rio Grande do Sul. The natural characteristics of this focus and its implication in the transmission of T. cruzi are discussed.

The prime objective in the surgical treatment of basilar impression (BI), Chiari malformation (CM), and/or syringomyelia (SM) is based on restoration of the normal cerebrospinal fluid (CSF) dynamics at the craniovertebral junction and creation of a large artificial cisterna magna, avoiding the caudal migration of the hindbrain. It is observed that a large craniectomy might facilitate an upward migration of the posterior fossa structures. There are many surgical techniques to decompress the posterior fossa; however, a gold standard approach remains unclear. The authors present the results of 192 cases of BI, CM, and SM treated between 1975 and 2008 and whose surgical treatment was characterized by a large craniectomy without tonsillectomy with the patient in the sitting position, large opening of the fourth ventricle, and duraplasty.