COVID-19 associated mucormycosis – a recent challenge

Dear Editor, Mucormycosis has been considered an uncommon, life-threatening infection by filamentous fungi living in the soil and vegetable or animal-decomposing matter, causing the infection through superficial lesions and spore inhalation or ingestion, mainly in people with diabetes, malignancy, hematological diseases, or immunosuppression condition.1-12 We read the report by Bhowmik et al.2 about gastric mucormycosis incidentally diagnosed in the autopsy of an Indian man who died of septicemia one week after a road traffic accident. Gastrointestinal (GI) mucormycosis is estimated to occur in up to 13% of the invasive infections, involving the stomach in 58% of the cases, or the small and large intestines. However, only one-fourth of these cases have been clinically diagnosed.2 The authors emphasized the incidental diagnosis of this life-threatening mycosis by endoscopy or autopsy, which has increasing in frequency in recent decades.2 The mortality rate of GI mucormycosis is up to 78% of cases, with perforated ulcers and peritonitis being the leading causes of death.2 This letter aims to present a review of this issue, including articles from 2020 to 2023. Gurjar et al.1 reported a 22-year-old Indian woman who had acute pancreatitis two months after the normal delivery and evolved with thrombosis of the left cavernous venous sinus, diabetic ketoacidosis, and GI bleeding due to a large gastric perforation. Gastric samples revealed broad aseptate and foldable fungal hyphae and angioinvasion. She received intensive care support and underwent a laparotomy with subtotal gastrectomy, feeding jejunostomy, and ileostomy, in addition to amphotericin B and oral posaconazole. Notwithstanding, her clinical condition worsened, and she succumbed after six weeks. The authors emphasized the association of mucormycosis with diabetic ketoacidosis.1 Khsiba et al.7 reported fatal invasive gastric mucormycosis in a 61‐year‐old diabetic Tunisian woman and a previously healthy 59‐year‐old foreign man living in Tunisia. The woman had a one-week history of vomiting after 4 months of inhaled corticoids for cough, and the upper GI endoscopy with biopsy revealed invasive mucormycosis by Rhisopus arrhizus. The patient had to stop conventional amphotericin B due to a renal function impairment; she also underwent total gastrectomy 2 months after the diagnosis but died 10 days later.7 The male patient presented with gastric pain, vomiting, worsened general state, and fever; the upper GI endoscopy showed a bleeding gastric ulcer, and the biopsy study detected typical zygomycetes hyphae. He did not undergo specific treatment for mucormycosis, and the outcome included septic shock and hemophagocytic syndrome, dying after eight days of admission.7 The authors stressed the mortality being up to 85% without early diagnosis and therapy.7 Noor et al.10 reported a 21-year-old man presenting gastritis-like symptoms, who was recently treated for hemophagocytic lymphohistiocytosis, and a fungal sinusitis. The upper GI endoscopy revealed an extensive gastric involvement by mucormycosis, and the patient underwent antifungal drugs and resection of the necrotic gastric tissue. In this case, it was worthy of note the young age, the lack of risk factors such as diabetes or immunosuppression, and the development of hemophagocytic lymphohistiocytosis. The authors highlighted the role of early diagnosis and prompt treatment on outcome.10 Yuvaraj et al.12 described a 53-year-old man with diabetes mellitus and alcoholism who had acute abdominal pain and hematemesis. The imaging studies showed a gastric wall thickening and exophytic ulceration involving the greater curvature and the splenic hilum, and evidence of splenic infarction. Biopsy studies of the mass revealed broad aseptate branched fungal hyphae consistent with the diagnosis of gastric mucormycosis, and amphotericin-B was administered; however, the gastrectomy and splenectomy procedures were not performed because of the patient’s clinical condition, and he irreversibly evolved to death.12 The authors highlighted the high index of suspicion and physicians’ awareness needed for early diagnosis and treatment of mucormycosis, mainly in immunocompromised patients.12 Recent articles on COVID-19-associated mucormycosis (CAM) have been published.3-6,8,9 It is estimated a higher prevalence of CAM than the reported cases because of the lack of population-based research. Thus, CAM cases may be higher than the described ones.4 Patients with COVID-19 treated with intensive care support are prone to nosocomial and ventilator-associated infections.4,13 Chauhan et al.3 reported a 35-year-old man with fever, vomiting, delirium, dyspnea, and cough, in addition to melena. Pulmonary thromboembolism and bilateral ground glass opacities were revealed by chest imaging study. The upper GI endoscopy showed multiple gastric black ulcers. Histopathological examination of the gastric biopsy revealed a broad, classical aseptate, ribbon-like, and foldable pattern of the mucormycosis fungal hyphae. Under amphotericin B therapy, he presented mental confusion, paraparesis, and left upper limb weakness. Contrasted computed tomography showed ring-enhancing brain lesions that were considered as a manifestation of the yeast infection. Due to clinical suspicion of recent infection by SARS-CoV-2, the IgM test was positive. Treatment of this patient included posaconazole evolving to an asymptomatic clinical status and complete vanishing of the CNS lesions.3 Worthy of note is the disseminated mucormycosis in the absence of any apparent risk factor, except for COVID-19 infection that has been associated with prothrombotic conditions.3 Malakar et al.8 described an 82-year-old man with GI bleeding for five days who utilized prednisolone for 21 days to treat moderate COVID-19 infection 2 months ago. The upper GI endoscopy detected a gastric ulcer extending from the gastroesophageal junction, and biopsy studies showed fungal hyphae consistent with gastric mucormycosis. For 13 days, he used pantoprazole and amphotericin B, which was changed by posaconazole due to worsening renal function and continued for three months till the ulcer was healed.8 The authors emphasized a rare cause of GI bleeding in a patient who had COVID-19, and the extensive mucormycosis successfully treated by anti-fungal therapy without surgery.8 Monte et al.9 described an 86-year-old man presenting with acute diarrhea, cough, dyspnea, and fever five days before, and a throat swab confirmed COVID-19.9 With acute respiratory failure and hemodynamic instability, he had intensive care support and underwent a schedule of ceftriaxone, azithromycin, oseltamivir, and hydrocortisone. Five days later, he had melena, and the upper GI endoscopy showed two giant gastric ulcers in greater and lesser curvatures; a histopathological study confirmed mucormycosis, but the patient died one week following admission and before the established diagnosis. The authors cited preemptive therapy in a patient with features suggesting mucormycosis.9 Dam et al.4 reviewed the pathogenesis, causal agents, determinants, distributions, manifestations, virulence factors, case reports, diagnosis, and treatment related to the increasing trend of mucormycosis in several countries and the COVID-19 co-infections. The study comprised 388 cases and showed 46.7% of global mortality; 56.8% of the cases were associated with uncontrolled diabetes and 10.2% with trauma, the majority of cases and the higher mortality rate were observed in North India (82.7%).4 GI infection was uncommon and with nonspecific symptoms, affecting the large intestine (∼43.2%), stomach (∼33%) often in adults, and small intestine (∼28.4%), mainly in children. The mortality was 96% in disseminated, 85% in GI, and 76% in pulmonary infections.4 The authors stressed the risk of improper use of antifungal drugs for the mucormycosis surge in the present pandemic, which might contribute to antifungal resistance over time.4 Didehdar et al.5 reviewed 87 reports of GI mucormycosis from 2015 to November 2021, including 70 adults and ten neonatal patients, the majority of cases (57.5%) from Asia. The mortality rate of neonatal patients was 70%, the other cases had a mortality rate of 44%; corticosteroid use and diabetes were the main risk factors, 11% were immunocompetent, and four of the adults presented with specific positivity tests of COVID-19 infection.5 Abdominal pain, fever, and perforation were common; 40% of the neonatal cases presented vomiting. Surgery plus antimycotic agent (61%), antimycotic therapy alone (28%), and surgery alone (11%) were the therapeutic approaches. All neonatal patients underwent a surgical procedure; posaconazole (30%) and isavuconazole (11%) effectively treated these patients.5 The authors commented on low immunity during the COVID-19 pandemic favoring the high prevalence of mucormycosis in India and the difficulties of early diagnosis and treatment.5 Divakar6 reviewed data about mucormycosis in general and the cases associated with the two waves of COVID-19 infections in India.6 The estimated mortality rate of mucormycosis (50%) may be over 90% if untreated; Rhizopus arrhizus was the most common agent of human mucormycosis described in Indian patients, followed by Apophysomyces variabilis, R. microsporus, and R. homothallicus.6 Mucormycosis among COVID-19 patients, including the mortality rate, are increasing in India and some of the neighboring countries such as Bangladesh, Nepal, and Pakistan.6 Because of species-specific differences, there are therapeutic challenges in India, with only three potentially efficient drugs (amphotericin B, posaconazole, and isavuconazole). The authors cited accurate species identification as crucial for the correct diagnosis of mucormycosis, and for developing species-specific antifungal drugs.6 In conclusion, although considered a rare entity, GI mucormycosis must be a plausible hypothesis if an atypical gastric ulcer is detected in people with COVID-19

GESTÃO E AVALIAÇÃO DA EDUCAÇÃO SUPERIOR NO BRASIL A PART

Resumo O artigo pretende contribuir com a discussão sobre a relação entre gestão e avaliação da educação superior no Brasil a partir dos anos de 1990 até a contemporaneidade. Tem como objetivo analisar as perspectivas de avaliação adotadas em diferentes momentos da gestão governamental e suas vinculações com os contextos sócio-políticos e econômicos mais amplos. Apresenta argumento que visam demonstrar que, apesar dos discursos mais recentes acerca do caráter formativo do modelo de avaliação da educação superior adotada no Brasil, o vetor que direciona a avaliação tende, ainda, para o seu papel de controle e regulação da gestão. Para dar conta do objetivo proposto, o artigo se apresenta estruturado em dois itens que tratam dos seguintes aspectos: a) reflexões acerca da relação entre avaliação e gestão da educação na contemporaneidade; b) a relação entre avaliação e gestão na educação superior no Brasil a partir dos anos 1990. Nas considerações finais apresenta um conjunto de reflexões que sinalizam para novas pesquisas na área, propondo o aprofundamento de estudos que vislumbrem como no cotidiano das IES se evidenciam as contradições entre os objetivos da regulação e da emancipação presentes no modelo de avaliação da educação superior brasileira

Metastatic leiomyosarcoma of the excluded stomach: a case report

Background:Leiomyosarcoma (LMS) represents about 1% of primary malignancies of the stomach, usually evolves with hepatic implants in 2-thirds of cases, and the outcome is frequently poor. With an insidious course, late diagnosis and misdiagnosis with other gastric neoplasia occur. Immunohistochemical evaluations are mandatory to confirm the diagnostic hypothesis. Surgical resection has been the more effective treatment ofgastric LMS; however, recurrences after resections and distant metastases may develop in up to 50% of the patients. Doxorubicin, gemcitabine, and docetaxel are therapeutic options, with variable responses.Case presentation:The 52-year-old male herein described with a diagnosis of LMS in the gastric pouch and liver metastasis underwent a Roux-en-Y bypass to treat morbid obesity more than a decade ago. Persistent abdominal pain was a unique symptom, and he had liver metastasis at diagnosis. The initial hypothesis was a metastatic gastrointestinal stromal tumor (GIST) of the excluded stomach and the patient underwent a schedule with imatinib without significant response. After a complete revision of the anatomopathological findings,the patient underwent a new biopsy of the gastric mass, and the immunohistochemical data were consistent with LMS. Then doxorubicin replaced imatinib, later changed by gemcitabine associated with docetaxel. As last control found lesions in the central nervous system, he is under radiotherapy sessions.Conclusion:The diagnosis of gastric LMS often occurs at late stages because of the insidious clinical course. The rate of liver metastasis at diagnosis is high. Besides, the relatively poor response to the alternative management for non-surgical stages of the disease yields severe outcomes

Lean logistics as support for strategic management practice

According to Hines, Holweg and Rich (2004), lean can be applied across several segments, including supply chain aspects, providing benefits to the organization. Within these practices, the logistics aspects are heavily involved and, for this reason, are fundamental to the added value and success of the philosophy. The term "lean logistics", which for Nishida (2009), covers the planning and management of all logistic activities, under the lean thinking approach.Logistics, besides being responsible for meeting the needs of customers and companies, also adds value to the product, since customers value the fact that a product is available at the precise moment, and also in the place. Santos and Santos (2018) complements and cites that the main goal of logistics is to deliver the right materials, in the right places, in the right quantities, and secondly to do all these activities as efficiently as possible. In this context, this intervention aims to analyze improvements in the level of logistics service of a company from the application of lean tools

Influência e persuasão na negociação

Monografia (graduação)—Universidade de Brasília, Faculdade de Direito, 2015.Este trabalho monográfico se dedica a estudar a negociação, especificamente, a relação que possui com a influência e a persuasão. A negociação tem ganhado cada vez mais espaço na resolução de disputas em razão de suas diversas vantagens. É notório o estímulo que o Judiciário, o Executivo e o Legislativo têm feito para que cresça o número de conflitos solucionados pelos meios consensuais. A negociação é uma das maneiras mais eficientes e céleres para tanto, e possui forte relação com o direito, uma vez que negociar faz parte da prática jurídica. Além disso, os acordos produzidos em uma negociação devem ser legítimos e justos, de modo que o advogado possui relevante papel nesse contexto. A negociação é entendida aqui como uma comunicação que se volta à persuasão e, por isso, o estudo da persuasão e da influência serão aprofundados neste trabalho. O modelo intuitivo de negociação não é o mais satisfatório e eficaz, de forma que o negociador deve utilizar-se das estratégias e técnicas apresentadas por cientistas sociais que estudam o processo de tomada de decisões do ser humano, bem como técnicas de influência. Este trabalho monográfico buscou pesquisar diversos métodos para aumentar a influência em uma negociação, de maneira especial, as rotas de influência de Lewicki e os princípios de influência de Cialdini. Apropriar-se desse conhecimento traz benefícios aos negociadores e seus clientes, e proporciona negociações mais eficazes. _____________________________________________________________________________ ABSTRACTThis monograph is devoted to studying the negotiation, specifically, the relationship it has with the influence and persuasion. The negotiation has gained more and more space in resolving disputes because of its various advantages. It is clear the stimulus that the Judiciary, the Executive and the Legislature have done to grow the number of conflicts resolved by consensual means. Negotiation is one of the most efficient and fastest ways to do so, and has a strong relationship with the Law, since negotiating is part of the legal practice. In addition, the agreements produced in a negotiation must be legitimate and fair, so lawyers have an important role in this context. Negotiation is understood here as a communication that refers to persuasion and therefore the study of persuasion and influence will be further developed in this work. The intuitive model of negotiation is not the most satisfactory and effective, so that the negotiator should be used strategies and techniques presented by social scientists who study the process of decision making of the human being, and influence techniques. This monographic study aimed to research several methods to increase the influence in a negotiation, in a special way Lewicki's routes of influence and Cialdini's principles of influence. Taking ownership of this knowledge brings benefits to dealers and customers, and provides more effective negotiations

O manejo neonatal e suas implicações na rinotraqueite viral felina: relato de caso

Esse trabalho objetivou relatar dois casos de Rinotraqueíte Viral Felina em neonatos felinos atendidos no Hospital Veterinário Adílio Santos de Azevedo (HV-ASA), avaliando a influência do manejo neonatal na ocorrência da doença. Quatro neonatos felinos, SRD, em média de cinco dias de vida e 60g, resgatados, foram atendidos no Hospital Veterinário Adílio Santos de Azevedo (HV-ASA) do IFPB, com histórico de exposição a uma fêmea felina e seu filhote com sintomas respiratórios na tentativa de aleitamento natural, sem sucesso. Após cinco dias, do contato, dois animais apresentaram conjuntivite, secreção nasal serosa, espirros e crepitação inspiratória. Tendo diagnóstico presuntivo de Rinotraqueíte Viral Felina que se deu baseado na anamnese e sinais clínicos apresentados nos animais e epidemiologia da doença. Orientações de manejo foram repassados aos tutores, instituída terapia a base de Cefalexina, suplemento vitamínico, óleo mineral e limpeza ocular com NaCl 0,9%. Após o tratamento os dois animais se recuperaram, receberam transição de alimentação e manejo higiênico de caixa de areia sem dificuldades na aceitação, e sanitário com vacinação e castração. Conclui-se que, diversas falhas de manejo neonatal juntamente com a baixa imunidade fisiológica, pela não ingestão do colostro contribuíram para a manifestação clínica do Herpes vírus Felino tipo 1 (FHV-1) em dois neonatos felinos

A criatividade no trabalho pedagógico do Professor e o movimento em sua subjetividade

Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2014.Esta pesquisa possui como tema a criatividade no trabalho pedagógico do professor e os movimentos na subjetividade dos docentes, a partir das produções subjetivas que se formam no curso dessa expressão criativa. Tivemos como objetivo geral: compreender processos subjetivos que configuram a criatividade no trabalho pedagógico do professor e suas inter-relações com o movimento em sua subjetividade. Assumimos, neste estudo, a definição de criatividade como processo complexo da subjetividade humana, na simultânea condição de subjetividade individual e subjetividade social, a qual se expressa no trabalho pedagógico por meio de novidades com valor para o processo de aprendizagem e desenvolvimento dos estudantes, conforme a abordagem teórica de Mitjáns Martínez. E a subjetividade que se define segundo a perspectiva Histórico-Cultural desenvolvida por González Rey. Para a investigação empreendida, pautamo-nos na Epistemologia Qualitativa e na realização de três estudos de casos com professores da rede pública de ensino do Distrito Federal. Para a construção das informações, utilizamos como instrumentos: observação; análise documental; entrevistas; túnel do tempo; redações; completamento de frases; resolução de situações do cotidiano educativo; conversas informais; dentre outros. O processo construtivo-interpretativo nos permitiu formular a tese de que os processos subjetivos que configuram a criatividade no trabalho pedagógico do professor são singulares, históricos e atuais e se relacionam de forma recursiva aos próprios processos de movimento em sua subjetividade. Dentre os processos subjetivos que configuram essa criatividade, encontram-se: a subjetivação do papel do professor, vinculado à responsabilidade frente ao trabalho pedagógico; a subjetivação do aluno como ativo e participativo no processo de aprendizagem; a subjetivação da aprendizagem escolar relacionada à compreensão e a elaboração pessoal a partir do aprendido; a subjetivação da função social da educação concebida como a formação integral dos estudantes; a subjetivação de conhecimentos de áreas específicas, que se expressam no trabalho pedagógico realizado. Além desses processos, a construção das informações do estudo de casos nos permitiu compreender a participação, na criatividade do trabalho pedagógico do professor: da imaginação; da intencionalidade pedagógica, da autoria e protagonismo do professor como expressão de sua condição de sujeito; de núcleos subjetivos específicos de sua subjetividade individual; e, do funcionamento psicológico criativo, expressão da dimensão funcional da criatividade. Por último, uma importante construção desta pesquisa, foi a consideração do aluno como um outro social que participa da criatividade no trabalho pedagógico do professor, por meio de necessidades pedagógicas e desafios educativos que implicam o docente para a produção de novidades com valor para o seu processo de aprendizagem e desenvolvimento.The main theme of this research relates to teachers’ creativity in pedagogical work and the movements in the subjectivity of teachers derived from subjective productions that form in the course of this creative expression. Its general objective is to understand subjective processes that configure the teacher’s creativity in pedagogical work and their interrelations with the movement in the teacher’s subjectivity. In accordance with Mitjáns Martínez’s theoretical approach, we assume, in this study, the definition of creativity as a complex process of human subjectivity, in its simultaneous condition of individual subjectivity and social subjectivity, which is expressed in the pedagogical work through innovations of value to the process of learning and development of students. We assume, as well, the conception of subjectivity from a Historical-Cultural perspective as developed by González Rey. As for the research methodology, we undertook the Qualitative Epistemology approach through the analysis of three case studies with teachers in public schools of the Federal District. For the construction of information, we used instruments such as: observation; document analysis; interviews; time warp; essays; completing phrases; resolution of the education everyday situations; and informal conversations. The constructive-interpretive process allowed us to formulate the hypothesis that the subjective processes that shape the creativity in the teacher’s pedagogical work are singular, historic and actual; and they recursively relate to movement processes of the teacher’s subjectivity. Among the subjective processes that shape this creativity are: the subjectivation of the teacher's role associated to the responsibility towards the pedagogical work; the subjectivation of the learner as an active and participative instance in the learning process; the subjectivation of school learning as the understanding and the personalization of what is learnt; the subjectivation of the social function of education, conceived as the integral formation of the students; the subjectivation of knowledge in specific areas that are expressed through the intended pedagogical work. In addition to these subjective processes, the construction of information in the case studies allowed us to understand the participation of the following aspects in the teacher’s creativity in pedagogical work: the imagination; the pedagogical intentionality, the authourship and the protagonism of the teacher as an expression of his/her subject condition; specific subjective cores of his individual subjectivity; and the creative psychological functioning, an expression of the functional dimension of creativity. Finally, one of our significant research constructions was the understanding of the student as a social other who participates in the teacher’s creativity in pedagogical work through his/her educational needs and educational challenges that require the teacher to produce novelty with value for his/her learning and development processes.Cette recherche a pour thème la créativité dans le travail pédagogique des enseignants et les mouvements de la subjectivité des enseignants, depuis des productions subjectives qui se forment pendant cette expression créative. L’objectif général est comprendre processus subjectifs qui configurent la créativité dans le travail pédagogique d’ enseignant et de leurs interrelations avec le mouvement dans sa subjectivité. Dans cette étude, on supposée la définition de la créativité comme un processus complexe de la subjectivité humaine, dans la condition simultanée de la subjectivité individuelle et de la subjectivité sociale, qui s’exprime dans le travail pédagogique au moyen des innovations avec la valeur au processus d'apprentissage et de développement des élèves, selon l’approche théorique de Mitjáns Martínez. Et la subjectivité qui se définie en fonction de la perspective Historique et Culturelle développée par González Rey. Dans le recherche menée, on a guidé pour l’Épistémologie Qualitative et pour la réalisation des études de cas avec trois enseignants des écoles publiques du District Fédéral (Brésil). Pour obtenir les informations, on a utilisé les instruments suivants: l’observation; l'analyse de documents; les interviews; tunnel de temps; les essais; le compléter des phrases; le résolution des situations quotidiennes d’éducation; conversations informelles; et autres. Le processus de construction et interprétation a permis formuler l'hypothèse que les processus subjectifs qui façonnent la créativité dans le travail pédagogique des enseignants sont uniques, historiques et actuelles et se rapportent de manière récursive aux prope processus de mouvement dans leur subjectivité. Parmi les processus subjectifs qui façonnent cette créativité, on trouve: la subjectivation du rôle de l'enseignant, liée à la responsabilité pour le travail pédagogique; la subjectivation d’éleve comme un actif et participatif dans le processus d'apprentissage; la subjectivation de l'apprentissage scolaire lié à la compréhension et le développement personnel depuis l'appris; la subjectivation de la fonction sociale de l'éducation conçue comme la formation intégrale des étudiants; la subjectivation des connaissances dans des domaines spécifiques, qui sont exprimés dans le travail pédagogique. En plus de ces processus, la construction de l'information d’étude de cas nous a permis de comprendre la participation dans la créativité du travail pédagogique de l'enseignant: l'imagination; l’intentionnalité pédagogique, l’écrit et le rôle de l'enseignant comme une expression de sa condition de sujet; le noyau subjective spécifique de sa subjectivité individuelle; et le fonctionnement psychologique de création, qui est l'expression de la dimension fonctionnelle de la créativité. Enfin, un important construction de cette recherche, c’était la consideration de l'élève comme un autre sociale qui participant de la créativité dans le travail pédagogique d’enseignants, par l'intermédiaire de demandes éducatifs et de défis de l'éducation qui impliquent des enseignants à produire des nouvelles avec valeur pour le processus d'apprentissage et le développement

Desenvolvimento de sensores eletroquímicos a base de Ni E NiCo (Liga eletrodepositada) para detecção de processos de fragilização por hidrogênio

Orientador : Prof. Dr. Cláudia E. B. MarinoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Materiais e Processos - PIPE. Defesa: Curitiba, 18/03/2011Bibliografia: fls. 133-150Área de concentração: Engenharia e ciência de materiaisResumo: Nos ultimos anos, o Brasil vem se destacando com a ampliacao na prospeccao e extracao de petroleo. Desta forma ha um aumento da incidencia dos processos de corrosao e fragilizacao por hidrogenio em dutos. O principal desafio e como quantificar, de modo seguro, rapido e economicamente viavel, a presenca de hidrogenio proximo a uma superficie sujeita a corrosao. Sendo assim, esta pesquisa teve como objetivo estudar o comportamento eletroquimico do sistema a base de niquel e liga de niquel-cobalto eletrodepositados em substrato de aco inoxidavel AISI 316, sob carregamentos ciclicos de hidrogenio em tres densidades de corrente catodica (40, 60 e 80 mA/cm2) em tres tempos (10,20 e 30 min), atraves da variacao do seu potencial de circuito aberto (OCP), para verificar a interacao destes materiais frente ao hidrogenio. A tecnica eletroquimica de voltametria ciclica, e de caracterizacao, como microscopia eletronica de varredura (MEV) e difratometria de raios-X (DRX) foram empregadas antes e depois dos ciclos de carregamento de hidrogenio para verificar possiveis alteracoes nos eletrodos. Como forma complementar, foram realizados ensaios de permeacao de hidrogenio utilizando a tecnica de Devanathan-Stachurski com o intuito de estimar a sensibilidade e permeabilidade destes materiais. De acordo com as curvas de potencial de circuito aberto obtidas, os eletrodos de niquel eletrodepositado e da liga de iquel-cobalto eletrodepositada apresentaram resposta ao hidrogenio reduzido na superficie ja nos estagios iniciais de carregamento. Isto foi constatado com a variacao entre o primeiro e o ultimo ciclo de carregamento de hidrogenio para a densidade de corrente catodica de 40 mA/cm2 no tempo de 10 minutos, sendo mais evidenciada no eletrodo de niquel eletrodepositado (ƒ'E=0,09), em relacao a liga de niquel-cobalto (ƒ'E=0,03). Alem disso, o eletrodo de niquel eletrodepositado apresentou uma maior reversibilidade em relacao a liga de niquel-cobalto eletrodepositada. Esta conclusao esta sustentada na variacao do potencial de equilibrio (Ciclo 0), onde para o eletrodo de niquel eletrodepositado os valores tendem para valores menos catodicos devido a reducao do oxido/hidroxido observada tambem pela tecnica de voltametria ciclica, enquanto que o potencial de equilibrio para a liga de niquel-cobalto tende para valores mais catodicos indicando que o hidrogenio interage diretamente com a superficie do material. Esta metodologia empregada se mostrou eficiente e de baixo custo, detectando o hidrogenio ja nos estagios iniciais de incorporacao e permitindo estudar os mecanismos de interacao. Ja a caracterizacao por MEV confirmou que os eletrodos nao sofreram alteracoes na morfologia. E pela tecnica de DRX o diametro medio foi calculado permitindo verificar que o hidrogenio ficou menos retido no eletrodo de niquel eletrodepositado, sendo mais solubilizado no eletrodo de niquel-cobalto A partir da tecnica de permeacao de hidrogenio foi observado que os eletrodos apresentaram tempos de deteccao semelhantes (27 min), confirmando a hipotese que estes materiais podem ser utilizados como matriz ativa em sensores de hidrogenio.Abstract: In the last years, Brazil has been highlighting with the increase in prospecting and extracting oil. In this way there is an increased incidence of cases of corrosion and hydrogen embrittlement in pipes. The main challenge is how to quantify, safely, fast and economically feasible, the presence of hydrogen near the surface subject to corrosion. Thus, this research aimed to study the behavior electrochemical of he system the base of nickel and nickel alloy-cobalt electrodeposition on a substrate of AISI 316 stainless steel under cyclic loading of hydrogen in three cathodic current densities (40, 60 and 80 mA/cm2) in three times (10, 20 and 30 min) through the variation of its open circuit potential (OCP), to verify the interaction of these materials to hydrogen. The electrochemical technique of cyclic voltammetry, and haracterization, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed before and after the cycles of loading of hydrogen to verify possible changes in the electrodes. As a complement, tests were performed using the hydrogen permeation technique of Devanathan-Stachurski in order to estimate the sensitivity and permeability of these materials. According to the curves open circuit potential obtained, the electrodes of electrodeposited nickel and nickel-cobalt electrodeposited showed reduced response to hydrogen on the surface in the early stages of loading. This was observed with the variation between the first and last loading cycle of hydrogen to the cathode current density of 40 mA/cm2 in 10 minutes time, being more evident with electrodeposited nickel electrode (ƒ'E=0.09 V), for nickel-cobalt (ƒ'E=0.03 V). In addition, the electrode nickel electrodes presented greater reversibility in relation to nickel-cobalt electrodeposited. This conclusion is sustained in the variation of potential balance (cycle 0), where for the electrode of electrodeposited nickel values tend to values less due to reduction of the cathode oxide / hydroxide also observed by cyclic voltammetry technique, while the equilibrium potential for nickel-cobalt cathode tends to values indicating that more hydrogen interacts directly with material surface. This methodology was efficient and low cost, detecting hydrogen in the early stages of incorporation and allowing the study of the mechanisms of interaction. Already the characterization by SEM confirmed that the electrodes were not changed in morphology. By XRD technique the mean diameter was calculated to verify that the H was less retained in nickel electrode electrodeposited, being more solubilized in electrode nickel-cobalt.From the hydrogen permeation technique was observed that the electrodes had similar times to detection (27 min), onfirming the hypothesis that these materials can be used as active matrix in hydrogen sensors