Índice de PaO2/FAO2: ¿un mejor indicador de oxigenación para valorar la hipoxemia? Resultados de un análisis de concordancia con el índice de PaO2/FiO2 / PaO2/FAO2 index: a better oxygenation indicator to assess hypoxemia? Results of an analysis of agreement with the PaO2/FiO2 index / Índice PaO2/FAO2: melhor indicador de oxigenação para avaliar hipoxemia? Resultados de uma análise de concordância com o índice de PaO2/FiO2

Resumen: Introducción: el cociente PaO2/FiO2 ajustado a la presión barométrica se utiliza para evaluar la oxigenación en la falla respiratoria; sin embargo, no toma en cuenta la PaCO2, a diferencia del índice PaO2/FAO2 (PaO2 dividida entre la fracción alveolar de oxígeno). Objetivo: evaluar la concordancia entre PaO2/FiO2 y PaO2/FAO2. Material y métodos: estudio observacional, ambispectivo, transversal y analítico en pacientes mayores de 18 años, bajo ventilación mecánica invasiva, con falla respiratoria hipoxémica y con diferentes valores de PaCO2. Resultados: se analizó la concordancia en 64 mediciones gasométricas tomadas al ingreso y cuando se documentó la mayor PaCO2 de 32 enfermos. El análisis de Bland y Altman mostró una media de las diferencias (bias) de 13 y un límite de concordancia de 95%, entre 54 y -24. La concordancia es mejor cuando la PaO2/FiO2 es menor de 150. Veintidós por ciento de las mediciones no concordaron en la asignación a grupos con hipoxemia leve, moderada o grave. Conclusiones: existe una moderada concordancia entre la PaO2/FAO2 y la PaO2/FiO2; sin embargo, en los enfermos con hipoxemia severa la concordancia es mejor. En los pacientes con PaO2/FiO2 ≥ 150, la hipercapnia explica en parte la baja concordancia. Posiblemente la PaO2/FAO2 es una mejor forma de evaluar el grado del trastorno en la oxigenación.

Abstract: Introduction: the PaO2/FiO2 ratio adjusted to barometric pressure is used to assess oxygenation in respiratory failure; however, it does not take PaCO2 into account, unlike the PaO2/FAO2 ratio (PaO2 divided by the alveolar fraction of oxygen). Objective: to evaluate the agreement between PaO2/FiO2 and PaO2/FAO2. Material and methods: observational, ambispective, cross-sectional and analytical study in patients older than 18 years, under invasive mechanical ventilation with respiratory failure and with different PaCO2 values. Results: agreement was analyzed in 64 gasometric measurements taken at admission and when the highest PaCO2 was documented, of 32 patients. The Bland and Altman analysis showed a mean of the differences (bias) of 13 and a 95% limit of agreement, between 54 and -24. Agreement is better when PaO2/FiO2 is greater than 150. Twenty two percent of the measurements did not agree in the assignment to groups with mild, moderate, or severe hypoxemia. Conclusions: there is moderate agreement between PaO2/FAO2 and PaO2/FiO2; however, in patients with severe hypoxemia, agreement is better. In patients with PaO2/FiO2 ≥ 150, hypercapnia partly explains the low agreement. PaO2/FAO2 is possibly a better way to assess the degree of oxygenation disturbance.

Resumo: Introdução: o cociente PaO2/FiO2 ajustado à pressão barométrica é utilizada para avaliar a oxigenação na insuficiência respiratória; entretanto, não considera a PaCO2, ao contrário da relação PaO2/FAO2 (PaO2 dividida pela fração alveolar de oxigênio). Objetivo: Avaliar a concordância entre PaO2/FiO2 e PaO2/FAO2. Material e métodos: estudo observacional, ambispectivo, transversal e analítico em pacientes maiores de 18 anos, sob ventilação mecânica invasiva com insuficiência respiratória hipoxêmica e com diferentes valores de PaCO2. Resultados: analisou-se a concordância em 64 gasometrias feitas na admissão e quando documentou-se a maior PaCO2, de 32 pacientes. A análise de Bland e Altman mostrou uma média das diferenças (bias) de 13 e limite de concordância de 95%, entre 54 e -24. A concordância é melhor quando a PaO2/FiO2 é maior que 150. 22% das medidas não concordaram na alocação dos grupos com hipoxemia leve, moderada ou grave. Conclusões: existe uma concordância moderada entre PaO2/FAO2 e a PaO2/FiO2; no entanto, em pacientes com hipoxemia grave a concordância é melhor. Em pacientes com PaO2/FiO2 ≥ 150, a hipercapnia explica em parte a baixa concordância. Possivelmente a PaO2/FAO2 seja a melhor forma de avaliar o grau de distúrbio da oxigenação.

Percepção dos internos de Medicina acerca do atendimento destinado às pessoas com deficiência: modelo curricular insuficiente? / Perception of Medical interns about assisting people with disabilities: insufficient curriculum model?

Resumo Introdução: O conceito de deficiência relaciona-se às limitações socialmente impostas aos deficientes por seus corpos não corresponderem ao modelo aceito como normal. Em geral, o acesso à saúde dessa população é precário, em parte, pela falta de preparação voltada ao cuidado dos pacientes deficientes durante a formação médica, demonstrando que os currículos das faculdades necessitam de revisão. Objetivo: Este estudo teve como objetivo analisar a percepção do aluno interno do curso de Medicina da Universidade Federal do Ceará (UFC) acerca do modelo curricular atual no contexto da formação médica, especificamente voltado ao atendimento destinado às pessoas com deficiência. Método: Foi disponibilizado um formulário elaborado no Google Formulários, para coletar informações de internos da Faculdade de Medicina (Famed). Depois, realizaram-se entrevistas semiestruturadas via Google Meet mediante questões que objetivaram entender a relação entre futuros médicos e pessoas com deficiências, além da confiança do preparo para o atendimento a tais pacientes. Para exame do material empírico adquirido, utilizou-se a análise de discurso de Rueda. Resultado: Foram entrevistados 13 internos que relataram limitação no aprendizado do estabelecimento da relação médico-paciente em relação a pessoas com deficiência, durante o ciclo básico (do primeiro ao quarto semestre), evoluindo, principalmente, para o internato. Consideraram-se a educação, o entendimento das condições socioeconômicas e culturais do paciente, e a construção de um plano terapêutico executável as qualidades a serem desenvolvidas pelo interno. Quanto aos principais problemas relatados, destacou-se a dificuldade na realização do exame físico e na comunicação. Por sua vez, a ajuda de acompanhantes e o auxílio da equipe profissional foram apontados como aspectos positivos. Percepções referentes ao preparo para atender deficientes foram contrastantes: alguns relataram segurança por capacitações e conhecimentos empíricos, enquanto outros se sentiram inseguros ou incapazes. Percebe-se, também, importante consideração para haver adaptação curricular acerca desse tema, com intervenções nas disciplinas obrigatórias e optativas. Conclusão: Evidenciou-se que os entrevistados sentem dificuldades no atendimento destinado a deficientes, o que sugere alterações no currículo da Famed-UFC.

Abstract Introduction: The concept of disability is related to the socially-imposed limitations on the disabled because their bodies do not correspond to the model accepted as normal. Access to health care for this population is generally precarious, partly due to the lack of preparation for the care of disabled patients during medical school. This suggests that the school curricula need to be revised. Objective: To analyse the perception of the senior medical students at the Federal University of Ceará (UFC) about the current curriculum, specifically, in relation to the care of people with disabilities. Method: A form previously prepared on the Google Forms platform was made available to collect information from senior medical students at the School of Medicine (FAMED). Afterwards, semi-structured interviews were carried out via Google Meet using questions that aimed to understand the relations between future doctors and people with disabilities, as well as the confidence of the students in their preparation for caring for such patients. For analysis of the empirical material acquired, we used Rueda's speech analysis. Result: Thirteen interns were interviewed, who reported limitations in learning how to establish a doctor-patient relationship with patients with disabilities during the first two years of medical school, having effects on the future clinical rotations. Politeness, knowledge of the patient's socioeconomic and cultural conditions, and building an executable therapeutic plan were considered qualities to be developed by the student. The main problems reported was difficulty in performing the physical examination and communication with disabled patients. However, help from the patients' carers and from the professional team was considered positive by the students. Perceptions regarding the preparation to care for the disabled were contrasting: some reported confidence, due to training and empirical knowledge, while others felt insecure or incapable. It is also important to consider adapting the curriculum on this subject, with interventions in compulsory and elective subjects. Conclusion: Considering the responses and analyses, it was evident that the interviewees experience difficulties in caring for the disabled, suggesting changes to the FAMED-UFC curriculum.

Emergent surface superconductivity in the topological insulator Sb2Te3.

Surfaces of three-dimensional topological insulators have emerged as one of the most remarkable states of condensed quantum matter where exotic electronic phases of Dirac particles should arise. Here we report on superconductivity in the topological insulator Sb2Te3 with transition to zero resistance induced through a minor tuning of growth chemistry that depletes bulk conduction channels. The depletion shifts Fermi energy towards the Dirac point as witnessed by a factor of 300 reduction of bulk carrier density and by the largest carrier mobility (≳25,000 cm(2) V(-1) s(-1)) found in any topological material. Direct evidence from transport, the unprecedentedly large diamagnetic screening, and the presence of ∼25 meV gaps detected by scanning tunnelling spectroscopy reveal the superconducting condensate to emerge first in surface puddles, with the onset of global phase coherence at ∼9 K. The rich structure of this state lends itself to manipulation via growth conditions and the material parameters such as Fermi velocity and mean free path.

Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study.

PURPOSE: Current reports on acute kidney injury (AKI) in the intensive care unit (ICU) show wide variation in occurrence rate and are limited by study biases such as use of incomplete AKI definition, selected cohorts, or retrospective design. Our aim was to prospectively investigate the occurrence and outcomes of AKI in ICU patients. METHODS: The Acute Kidney Injury-Epidemiologic Prospective Investigation (AKI-EPI) study was an international cross-sectional study performed in 97 centers on patients during the first week of ICU admission. We measured AKI by Kidney Disease: Improving Global Outcomes (KDIGO) criteria, and outcomes at hospital discharge. RESULTS: A total of 1032 ICU patients out of 1802 [57.3%; 95% confidence interval (CI) 55.0-59.6] had AKI. Increasing AKI severity was associated with hospital mortality when adjusted for other variables; odds ratio of stage 1 = 1.679 (95% CI 0.890-3.169; p = 0.109), stage 2 = 2.945 (95% CI 1.382-6.276; p = 0.005), and stage 3 = 6.884 (95% CI 3.876-12.228; p < 0.001). Risk-adjusted rates of AKI and mortality were similar across the world. Patients developing AKI had worse kidney function at hospital discharge with estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) in 47.7% (95% CI 43.6-51.7) versus 14.8% (95% CI 11.9-18.2) in those without AKI, p < 0.001. CONCLUSIONS: This is the first multinational cross-sectional study on the epidemiology of AKI in ICU patients using the complete KDIGO criteria. We found that AKI occurred in more than half of ICU patients. Increasing AKI severity was associated with increased mortality, and AKI patients had worse renal function at the time of hospital discharge. Adjusted risks for AKI and mortality were similar across different continents and regions.

Flicker Noise as a Probe of Electronic Interaction at Metal-Single Molecule Interfaces.

Charge transport properties of metal-molecule interfaces depend strongly on the character of molecule-electrode interactions. Although through-bond coupled systems have attracted the most attention, through-space coupling is important in molecular systems when, for example, through-bond coupling is suppressed due to quantum interference effects. To date, a probe that clearly distinguishes these two types of coupling has not yet been demonstrated. Here, we investigate the origin of flicker noise in single molecule junctions and demonstrate how the character of the molecule-electrode coupling influences the flicker noise behavior of single molecule junctions. Importantly, we find that flicker noise shows a power law dependence on conductance in all junctions studied with an exponent that can distinguish through-space and through-bond coupling. Our results provide a new and powerful tool for probing and understanding coupling at the metal-molecule interface.

Chemopreventive effect of Copaifera langsdorffii leaves hydroalcoholic extract on 1,2-dimethylhydrazine-induced DNA damage and preneoplastic lesions in rat colon.

BACKGROUND: Natural antioxidants present in common foods and beverages have drawn great attention to cancer prevention due to its health benefits, remarkable lack of toxicity and side effects. Copaifera langsdorffii, known as "copaiba", "capaiva", or "pau-de-óleo", belongs to the Leguminosae family and occurs in fields and grasslands in the northern and northeastern parts of Brazil. Biological studies of Copaifera corroborate its widespread use by the population. This paper describes the effects of C. langsdorffii leaves hydroalcoholic extract on the 1,2-dimethylhydrazine (DMH)-induced DNA damage and aberrant crypt foci (ACF) in the colon of male Wistar rats. METHODS: The hydroalcoholic extract of C. langsdorffii was administered to rats by gavage at daily doses of 20, 40 and 80 mg/kg body weight. To evaluate DNA damage by the comet assay, animals received the C. langsdorffii extract for seven days and a single subcutaneous injection (sc) of 1,2-dimethylhydrazine (DMH) at a dose of 40 mg/kg on day 7. Animals were sacrificed 4 h after injection of DMH, to assess DNA damage. For the ACF assay, animals were acclimatized for one week (week 1) and then treated with the C. langsdorffii extract five times a week for four weeks (weeks 2 to 5). The rats received sc injections of DMH (40 mg/kg) on days 2 and 5 of weeks 2 and 3, to induce ACF. Animals were euthanized at week 5; i.e., four weeks after the first DMH treatment. RESULTS: Animals treated with different doses of the C. langsdorffii extract combined with DMH had significantly lower frequency of DNA damage as compared with the positive control (animals treated with DMH only). The percentage of reduction in the frequency of DNA damage ranged from 14.30% to 38.8%. The groups treated with 40 and 80 mg/kg C. langsdorffii extract during and after DMH treatment presented significantly lower numbers of ACF and aberrant crypts compared with the control. CONCLUSION: The C. langsdorffii extract significantly reduced the extent of DNA damage and ACF induced by DMH, suggesting that the extract has a protective effect against colon carcinogenesis.