Soluções para problemas de otimização no ensino médio através da teoria de grafos / Solutions for optimization problems in high school through graph theory

O presente trabalho apresenta um recorte de uma, de nove atividades, abordadas no Programa de Residência à Docência do Colégio Pedro II. Tal atividade tem por objetivo trabalhar análise combinatória no contexto de resolução de problemas com a utilização intuitiva dos grafos. A receptividade dos alunos foi positiva. Eles tiveram oportunidade de perceber a utilidade dessa área de conhecimento no meio em que vivem, como ela está presente no meio tecnológico e como auxilia na tomada de decisões.

Otimização discreta com grafos no Ensino Médio

O estudo de combinatória na Educação Básica tem sido alvo de pesquisas em Educação Matemática em diversos países, principalmente nas últimas décadas, incluindo as realizadas no Brasil (Kenneth, 2008; Neves & bolinhas, 2016; MUNIZ, 2007; SILVA, 2009). Entretanto, nossa revisão da literatura indicou que há um foco nos processos cognitivos voltados para a combinatória de contagem, sendo escassos os trabalhos que abordam combinatória de existência e/ou otimização combinatorial, incluindo os problemas envolvendo Grafos, conforme se pode ver em MUNIZ (2006;2007a). Este trabalho visa analisar a contribuição do ensino de grafos no ensino médio através de atividades investigativas e sem uso de fórmulas o ensino da Teoria de Grafos prévia. E o artigo mostra uma breve apresentação dos dados parciais de nossa investigação com os alunos

Otimização Discreta com Grafos no Ensino Médio

O objetivo desse artigo é apresentar o desenho de um produto educacional sobre combinatória e otimização, a partir de tarefas envolvendo otimização discreta com Grafos, voltado a sala de aula de matemática do Ensino Médio. Para isso, discutiremos as três etapas de desenvolvimento desse produto, que foram: (i) formulação de tarefas a partir de estudos recentes em educação matemática e das recomendações dos principais documentos curriculares vigentes no Brasil, aliadas às experiências curriculares de Portugal, Espanha e França sobre o tema, incluindo livros didáticos; (ii) implementação das tarefas com alunos de uma escola pública estadual na cidade Rio de Janeiro, Brasil; (iii) elaboração de um material didático para alunos – produto educacional – a partir dos resultados das etapas anteriores, incluindo uma investigação dos significados e conhecimentos produzidos pelos estudantes na fase de implementação

Conexões: questões de análise combinatória nos vestibulares ENEM e UERJ & possíveis reflexões para resolução de problemas no ensino médio / Connections: combinatorial analysis questions in ENEM and UERJ entrance exams & possible reflections for Problem Solving in High School

Este trabalho faz uma análise de uma coletânea de questões de análise combinatória de vestibulares do ENEM e Uerj. Buscamos analisar as questões e classificá-las em cinco categorias: contagem, existência, enumeração, otimização e classificação. Tal estudo é consequência da intersecção de estudos anteriores dos autores e o interesse em comum por essa temática. Ao abordarmos análise combinatória em sala de aula      vemos uma ênfase maior em problemas de contagem com aplicação de fórmulas. Nosso objetivo nesse trabalho foi investigar se nas questões de vestibular esse comportamento também se repete e criar observações acerca das questões e possíveis estratégias de resolução de problemas. Selecionamos dois vestibulares: ENEM e Uerj. Nossa escolha pelo ENEM se deu porque é um exame aplicado nacionalmente e Uerj porque é uma das poucas instituições públicas que manteve seu vestibular autônomo. Na tentativa de classificar tais questões de acordo com o referencial teórico usado, chegamos a outras análises e conexões interessantes que abordamos ao longo deste artigo

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Computational Mathematical Model Based on Lyapunov Function for the Hormonal Storage Control

Computational mathematical models have shown promise in the biological mechanism's reproduction. This work presents a computational mathematical model of the hormonal storage control applied to an endocrine cell. The model is based on a system of differential equations representing the internal cell dynamics and governed by the Lyapunov control function. Among the stages of these dynamics, we analyze the storage and degradation, which occur within some endocrine cells. The model’s evaluation considers, as an example, the synthesis–storage-release regulation of catecholamine in the adrenal medulla. Seven experiments, varying the input parameters, were performed to validate and evaluate the model. Different behaviors could be observed according to the numerical data used for future research and scientific contributions, besides confirming that Lyapunov control function is feasible to govern the cell dynamics

Aprendendo por osmose

Conhecimentos básicos sobre estrutura de células animais e vegetais, soluto, solvente, difusão e gradiente de concentraçãoCompreender o processo de osmose e os conceitos relacionados, tais como: gradiente de concentração, pressão osmótica, plasmólise, hemólise e etc, em células animais e vegetais, bem como suas implicações no funcionamento destes organismosComponente Curricular::Ensino Médio::Biologi

Aprendendo por osmose

Conhecimentos básicos sobre estrutura de células animais e vegetais, soluto, solvente, difusão e gradiente de concentraçãoCompreender o processo de osmose e os conceitos relacionados, tais como: gradiente de concentração, pressão osmótica, plasmólise, hemólise e etc, em células animais e vegetais, bem como suas implicações no funcionamento destes organismosComponente Curricular::Ensino Médio::Biologi

Article Synthesis and Trypanocidal Activity of Novel 2,4,5-Triaryl-N-Hydroxylimidazole Derivatives

Herein, we report the design, synthesis and trypanocidal activity of some novel trisubstituted imidazole derivatives. These heterocyclic derivatives were structurally planned by exploring the concept of molecular hybridisation between two arylhydrazones derived from megazol, which has potent trypanocidal activity. The trypanocidal activity of these triarylimidazole derivatives was evaluated against infective trypomastigote forms of T. cruzi and the derivative 2'-(4-bromophenyl)-1-methyl-5'-phenyl-1H,3'H-2,4'-biimidazol-3'-ol showed moderate biological activity (IC50 = 23.9 µM) when compared to benznidazole, a standard trypanocidal drug. These compounds did not present cytotoxic effects at concentrations near the trypanocidal IC50, being considered a good starting point for the development of new anti-Chagas drug candidates