Evolución de la virulencia de SARS-CoV-2 en Chile

Introducción: La evolución de la virulencia ha despertado el interés de la biología evolutiva por décadas. Se trata de co-evolución entre agentes patógenos y sus hospederos. Se han planteado diferentes hipótesis para la evolución de la virulencia, entre ellas la evolución con un compromiso virulencia-transmisión. Objetivo: Estudiar la evolución de la letalidad y la transmisión del SARS CoV-2 en Chile, con la hipótesis que ha existido un compromiso con disminución de la letalidad y aumento de la transmisión de esta durante la epidemia. Resultados: La letalidad diaria en Chile disminuyó claramente. Aunque no se encontró correlación entre la letalidad diaria y el número reproductivo efectivo, el número reproductivo efectivo máximo asociado a cada variante viral, presentó un aumento claro desde la aparición de la variante γ en adelante (δ y O) en Chile. Conclusión: Este estudio muestra una evolución de la virulencia con un compromiso virulenciatransmisión. Esto puede ser explicado en gran parte por la evolución viral, pero el cambio en letalidad también puede ser afectado por las intervenciones no farmacológicas y farmacológicas realizadas por la población humana.

Background: The evolution of virulence has aroused the interest of evolutionary biology for decades. It is about co-evolution between pathogens and their hosts. Different hypotheses have been put forward for the evolution of virulence, including evolution with a virulence-transmission trade-off. Aim: To study the evolution of the fatality rate and transmission of SARS CoV-2 in Chile, with the hypothesis that there has been a trade-off to a decrease in lethality and an increase in its transmission during the epidemic. Results: The daily fatality rate in Chile clearly decreased. Although no correlation was found between daily fatality rate and effective reproductive number, the maximum effective reproductive number associated with each viral variant showed a clear increase from the appearance of the γ variant onwards (δ and O) in Chile. Conclusion: This study shows an evolution of virulence with a virulence-transmission trade-off. This can be largely explained by viral evolution, but the change in lethality can also be affected by non-pharmacological and pharmacological interventions carried out by the human population.

La muestra en ensayos clínicos aleatorizados con análisis interino / Samples in randomized clinical trials with interim analysis

RESUMEN En este artículo se introducen los ensayos clínicos aleatorizados y conceptos básicos de la inferencia estadística. Se presenta como calcular el tamaño de muestra por tipo de desenlace e hipótesis a probar, junto con el código en el lenguaje de programación R para realizar su aplicación. Se presentan cuatro métodos para realizar el ajuste del tamaño de muestra original, cuando se planean análisis interinos. De una manera sencilla y concreta se busca realizar una introducción a estos temas, considerando las expresiones matemáticas que soportan los resultados y su implementación en programas estadísticos disponibles. Con el fin de acercar a los estudiantes de áreas de la salud a la estadística y al uso de programas estadísticos, aspectos poco considerados en su formación.

ABSTRACT This article introduces randomized clinical trials and basic concepts of statistical inference. We present methods for calculating the sample size by outcome type and the hypothesis to be tested, together with the code in the R programming language. We describe four methods for adjusting the original sample size for interim analyses. We sought to introduce these topics in a simple and concrete way, considering the mathematical expressions that support the results and their implementation in available statistical programs; therefore, bringing health students closer to statistics and the use of statistical programs, which are aspects that are rarely considered during their training.

Heart Smart Diabetes Care

The world is growing smarter day by day, and so is health care. In spite of innumerable inventions and tech-tools, however, we struggle to contain chronic illnesses like diabetes and heart disease. We need to work together and design a rational, scientific and socially sustainable Heart Smart diabetes care ecosystem, with Heart Smart management strategies, to ensure happiness and harmony in persons who live with diabetes.

Las hipótesis en el proyecto de investigación: ¿cuándo si, cuándo no?

La utilización de hipótesis en los proyectos de trabajo de terminación de la especialidad constituye uno de los aspectos metodológicos que amerita un análisis. El artículo pretende esclarecer a los investigadores jóvenes cuándo en una investigación debe ser declarada esta categoría. Se sugiere utilizar el alcance de la investigación (exploratorio, descriptivo, correlacional o explicativo) para la decisión de empleo o no de hipótesis en un proyecto investigativo. Se detallan condiciones que determinan el uso de hipótesis específicamente en los estudios descriptivos, los más frecuentemente realizados por los residentes.

The use of hypotheses in the specialty finishing projects constitutes one of the methodological aspects that deserves an analysis. The article aims to clarify for young researchers when this category should be declared in a research. It is suggested to use the scope of the research (exploratory, descriptive, correlational or explanatory) for the decision of whether or not to use hypotheses in a research project. Conditions that determine the use of hypotheses specifically in descriptive studies, the most frequently carried out by residents are detailed.

Heart Smart Diabetes Care

The world is growing smarter day by day, and so is health care. In spite of innumerable inventions and tech-tools, however, we struggle to contain chronic illnesses like diabetes and heart disease. We need to work together and design a rational, scientific and socially sustainable Heart Smart diabetes care ecosystem, with Heart Smart management strategies, to ensure happiness and harmony in persons who live with diabetes.

O impacto da pandemia da covid-19 na microbiota intestinal do lactente / The impact of the covid-19 pandemic on the infant gut microbiota / El impacto de la pandemia de covid-19 en la microbiota intestinal del lactante

A COVID-19 resultou em milhares de óbitos e até o presente momento assola diversos pacientes com as suas implicações. Uma das consequências da doença foi o isolamento social, realizado por quase todos os países, o que configurou a alteração de diversos padrões de convivência e principalmente de exposição a outros agentes não patogênicos e patogênicos essenciais para o desenvolvimento da microbiota. Com isso, o seguinte projeto tem como objetivo a descrição dos impactos da pandemia da COVID-19 na microbiota intestinal de lactentes do período pandêmico e as consequências geradas no sistema imunológico imaturo, prejudicando seu desenvolvimento e maturação. A metodologia consiste na análise e seleção de artigos científicos publicados nos últimos 10 anos com auxílio de Descritores em Ciências da Saúde (DeCS) específicos nas línguas inglesa e portuguesa para o tema da pesquisa, sendo a combinação dos descritores feita por meio de operadores booleanos. Conclui-se que a composição da microbiota intestinal é iniciada intraútero e influenciada pela via de parto, contato pele a pele após o nascimento e pela presença da amamentação materna. A modificação das práticas durante a pandemia da COVID-19, pode alterar a microbiologia neonatal, assim como impactar na maturação do sistema imunológico do lactente, predispondo futuramente à doenças gastrointestinais, metabólicas e atópicas, como asma.

COVID-19 has resulted in thousands of deaths and until now is affecting many patients with its implications. One of the consequences of the disease was social isolation, carried out by almost all countries, which resulted in changes in different patterns of coexistence and mainly exposure to other non-pathogenic and pathogenic agents essential for the development of the microbiota. Therefore, the following project aims to describe the impacts of the COVID-19 pandemic on the microbiota of infants during the pandemic period and the consequences generated on the immature immune system, damaging its development and maturation and relating microbiology, essentially intestinal, throughout the project. The methodology consists of the analysis and selection of scientific articles published in the last 10 years with the help of specific Health Sciences Descriptors in English and Portuguese for the research topic, with the combination of descriptors made using Boolean operators. It is concluded that the composition of the intestinal microbiota begins in utero and is influenced by the mode of delivery, skin-to- skin contact after birth, and the presence of maternal breastfeeding. Modifying practices during the COVID-19 pandemic may alter neonatal microbiology and impact the maturation of the infant's immune system, potentially predisposing them to future gastrointestinal, metabolic, and atopic diseases such as asthma.

El COVID-19 ha provocado miles de muertes y todavía afecta a muchos pacientes con sus implicaciones. Una de las consecuencias de la enfermedad fue el aislamiento social, llevado a cabo por casi todos los países, que resultó en cambios en diferentes patrones de convivencia y principalmente exposición a otros agentes patógenos y no patógenos esenciales para el desarrollo de la microbiota. Com eso, el siguiente proyecto tiene como objetivo describir los impactos de la pandemia de COVID-19 en la microbiota de los lactantes durante el periodo pandémico y las consecuencias generadas sobre el sistema inmunológico inmaduro, perjudicando su desarrollo y maduración y relacionando la microbiología, fundamentalmente intestinal, a lo largo del proyecto. La metodología consiste en el análisis y selección de artículos científicos publicados en los últimos 10 años con la ayuda de Descriptores en Ciencias de la Salud específicos en inglés y portugués para el tema de investigación, con la combinación de descriptores realizada mediante operadores booleanos. Se concluye que la composición de la microbiota intestinal comienza intraútero y está influenciada por la vía de parto, el contacto piel a piel después del nacimiento y la presencia de la lactancia materna. La modificación de las prácticas durante la pandemia de COVID-19 puede alterar la microbiología neonatal y afectar la maduración del sistema inmunológico del lactante, predisponiéndolo potencialmente a enfermedades gastrointestinales, metabólicas y atópicas en el futuro, como la asma.

Analysis of family mutation type and two-hit hypothesis of a familial VHL Syndrome patient / 现代泌尿外科杂志

【Objective】 To explore the mutation type, clinical characteristics, molecular genetics and the two-hit type of a patient with familial Von Hippel Lindau (VHL) syndrome. 【Methods】 The data of the patient were collected. DNA was extracted from the peripheral blood and renal cell carcinoma sample. The VHL gene germline mutation site was detected with high throughput sequencing next generation sequencing (NGS). The two-hit site was identified with UCSCXena database, methylation-specific PCR (MSP) and microsatellite stability detection. 【Results】 The mutation site of the embryo line was located in c.500G>A R167Q mutation. The patient had single nucleotide polymorphism, but no clear loss of heterozygosity, methylation or system mutation. 【Conclusion】 The germline mutation in exon 3 is the basis for the clinical features of this familial renal cell carcinoma proband. The identification of the two-hit site is key to the occurrence of the disease, which is significant for the diagnosis and treatment. The use of the databases can guide the screening of mutations and methylation sites in familial renal cell carcinoma.

Discussion on the Treatment Thoughts of Bronchiectasis in Traditional Chinese Medicine based on Hypothesis of “Vicious Circle” / 中医杂志

Bronchiectasis is characterized by a “vicious cycle” involving compromised host defense， mpaired clearance of airway mucus， bacterial colonization， infections， and inflammation， leading to frequent acute exacerbations and diminished quality of life. Based on the hypothesis of “vicious circle”， this paper explores the treatment of bronchiectasis by traditional Chinese medicine （TCM） from three aspects. Firstly， dissipating excessive “phlegm” secretion and enhancing airway clearance form the foundation of the treatment， aiming to improve the condition of mucus hypersecretion. Secondly， invigorating spleen for strengthening vital energy can improve the function of immune system and reduce recurrent infections and acute attacks. Lastly， clearing heat and purging the lung can alleviate infection and inflammatory damage. By employing these methods， TCM can disrupt the progression of the “vicious circle”， delaying disease advancement， minimizing acute exacerbations， and improving the quality of life for patients.

The history, current situation and prospect of lacunar infarct / 中华神经科杂志

The modern concept of lacunar infarct is largely based on the meticulous postmortem work of Fisher from the 1950s to 1970s, which forms the basis of the"lacunar hypothesis". Along with the application of CT or MRI techniques and classification of ischemic stroke subtypes, the lacunar infarct was endowed with the profile of imaging diagnosis and stroke subtypes. Thus, the concept of lacunar infarct has far expanded the initial pathological meanings and the terminology and definitions for lacunar infarct vary widely. In this review, the historical pathological findings and the term evolution of lacunar infarct were systemically reviewed, with a focus toward future directions in the complex entity of lacunar infarct.

Research progress of the mechanism of Flash effect / 中华放射医学与防护杂志

The ultra-high dose rate (UHDR) radiation has less side effect while keep comparable tumor control effect with conventional dose rate (CONV) radiation, which was named Flash effect. Recently, the Flash effect has been reported in many animal experiments with various types of radiations, animal species and body parts. However, the underlying mechanism of Flash has still been unraveled, making difficulties for the clinical application. This review pointed out the differences between the Flash effect and the UHDR effect in vitro and proposed three key scientific questions of Flash effect based on three well-known hypotheses, i. e., oxygen depletion, peroxyl radical recombination and immune cell protection. Finally, the research progresses and challenges of Flash mechanism study are concluded in order to give a clue for further deep investigation.

Significancia Estadística en Ciencias de la Salud: Limitaciones y Alternativas / Statistical significance in the field of health sciences: limitations and alternatives

Introducción. La prueba de significancia de la hipótesis nula (PSHN) constituye la herramienta más usada para evaluar hipótesis científicas y tomar decisiones al respecto, en especial en ciencias de la salud. Sin embargo, por décadas ha estado en el centro del debate, ya que se han identificado varios problemas conceptuales y de interpretación. Se realizó una revisión de artículos científicos que ilustran las críticas de esta controversia y su relevancia en el ámbito de la investigación en salud. Algunas alternativas para la PSHN son una adecuada interpretación del valor p, uso de intervalos de confianza, incluir el tamaño del efecto y adoptar un marco de inferencia bayesiana. En todos los casos en que se utilice PSHN, su uso debe ser claramente justificado.

Background. Null hypothesis significance testing (NSHT) constitutes the most widely applied tool for the evaluation of scientific hypotheses and decision making in health sciences. However, the method has been the centre of a heated debate where various criticisms related to conceptual and interpretational problems. A review of scientific articles that illustrate the criticisms of this controversy and its relevance in the field of health research was carried out. Some alternatives for the NSHT are an adequate interpretation of the p-value, use of confidence intervals, including the effect size and adopting a Bayesian inference framework. In all cases where NSHT is used, its use should be clearly justified.

Reading digital- versus print-easy texts: a study with university students who prefer digital sources

The transition from on-paper to on-screen reading seems to make it necessary to raise some considerations, as a greater attentional efort has been claimed for print texts than digital ones. Not surprisingly, most university students prefer this digital medium. This research aims to examine reading times by contextualizing this phenomenon into two processes: namely, word recognition and reading comprehension task on paper and on screen. Thus, two diferent tasks­counterbalanced into digital and print mediums­were carried out per each participant with a preference for a digital medium: a reading comprehension task (RCT) and a lexical decision task (LDT) after reading a specifc story. Participants were slower reading print texts and no statistically signifcant diferences were found in RCT accuracy. This result suggests that the task required more cognitive resources under the print medium for those with a worse comprehension performance in reading, and a more conservative pattern in digital RCT for those with a better performance.

Frequentist and Bayesian Hypothesis Testing: An Intuitive Guide for Urologists and Clinicians / Pruebas de hipótesis frecuentista y bayesiana: Una Guía intuitiva para urólogos y clínicos

Given the limitations of frequentist method for null hypothesis significance testing, different authors recommend alternatives such as Bayesian inference. A poor understanding of both statistical frameworks is common among clinicians. The present is a gentle narrative review of the frequentist and Bayesian methods intended for physicians not familiar with mathematics. The frequentist p-value is the probability of finding a value equal to or higher than that observed in a study, assuming that the null hypothesis (H0) is true. The H0 is rejected or not based on a p threshold of 0.05, and this dichotomous approach does not express the probability that the alternative hypothesis (H1) is true. The Bayesian method calculates the probability of H1 and H0 considering prior odds and the Bayes factor (Bf). Prior odds are the researcher's belief about the probability of H1, and the Bf quantifies how consistent the data is concerning H1 and H0. The Bayesian prediction is not dichotomous but is expressed in continuous scales of the Bf and of the posterior odds. The JASP software enables the performance of both frequentist and Bayesian analyses in a friendly and intuitive way, and its application is displayed at the end of the paper. In conclusion, the frequentist method expresses how consistent the data is with H0 in terms of p-values, with no consideration of the probability of H1. The Bayesian model is a more comprehensive prediction because it quantifies in continuous scales the evidence for H1 versus H0 in terms of the Bf and the

Dadas las limitaciones del método de significancia frecuentista basado en la hipótesis nula, diferentes autores recomiendan alternativas como la inferencia bayesiana. Es común entre los médicos una comprensión deficiente de ambos marcos estadísticos. Esta es una revisión narrativa amigable de los métodos frecuentista y bayesiano dirigida quienes no están familiarizados con las matemáticas. El valor de p frecuentista es la probabilidad de encontrar un valor igual o superior al observado en un estudio, asumiendo que la hipótesis nula (H0) es cierta. La H0 se rechaza o no con base en un umbral p de 0.05, y este enfoque dicotómico no expresa la probabilidad de que la hipótesis alternativa (H1) sea verdadera. El método bayesiano calcula la probabilidad de H1 y H0 considerando las probabilidades a priori y el factor de Bayes (fB). Las probabilidades a priori son la creencia del investigador sobre la probabilidad de H1, y el fB cuantifica cuán consistentes son los datos con respecto a H1 y H0. La predicción bayesiana no es dicotómica, sino que se expresa en escalas continuas del fB y de las probabilidades a posteriori. El programa JASP permite realizar análisis frecuentista y bayesiano de una forma simple e intuitiva, y su aplicación se muestra al final del documento. En conclusión, el método frecuentista expresa cuán consistentes son los datos con H0 en términos de valores p, sin considerar la probabilidad de H1. El modelo bayesiano es una predicción más completa porque cuantifica en escalas continuas la evidencia de H1 versus H0 en términos del fB y de las probabilidades a posteriori.

A key issue of national health in China: excess energy intake and oxidative inflammation / 中国中药杂志

This study expounded the great impacts of excess energy intake and oxidative inflammation on national health in China and put forward the pathological mirror-image hypothesis of the relationship between obesity and oxidative inflammation. On this basis, an ideological framework was constructed to deal with oxidative stress and oxidative inflammation centered on the development of natural antioxidant products. The study contained the following four parts: the ways to improve national health in China; the promotion of cognition to oxidative inflammation to improve national health in China; prospects for the prevention and treatment of oxidative inflammation in China; the reason why Northwest Yunnan is a good place to develop high-quality natural antioxidants.

Uso del factor Bayes durante el análisis estadístico: un ejemplo / Use of the Bayes factor during statistical analysis: an example

El factor de Bayes resulta una prueba recomendable para la comprobación de las hipótesis esta-dísticas atendiendo al estado de los p valores, empleando la escala de clasificación de Jeffreys preferiblemente

The Bayes factor is a recommended test for the verification of statistical hypotheses taking into account the state of the p values, preferably using the Jeffreys classification scale.

O valor de p é adequadamente interpretado pelos profissionais de terapia intensiva? Uma pesquisa on-line / Is the p-value properly interpreted by critical care professionals? Online survey

RESUMO Objetivo: Determinar a prevalência e os fatores de risco para conhecimento insuficiente sobre valores de p entre médicos e terapeutas respiratórios atuantes em terapia intensiva na Argentina. Métodos: Levantamento transversal on-line com 25 questões relativas às características dos participantes, autopercepção e conhecimento sobre valores de p (teoria e prática). Realizaram-se análises de estatística descritiva e regressão logística multivariada. Resultados: Analisaram-se 376 participantes. Não tinham conhecimento a respeito dos valores de p 237 participantes (63,1%). Segundo análise de regressão logística multivariada, falta de treinamento em metodologia científica (RC ajustadas 2,50; IC95% 1,37 - 4,53; p = 0,003) e a quantidade de leitura (< 6 artigos científicos por ano; RC ajustadas 3,27; IC95% 1,67 - 6,40; p = 0,001) foram identificados como independentemente associados com a falta de conhecimento sobre valores de p por parte dos participantes. Conclusão: A prevalência de conhecimento insuficiente com relação a valores de p entre médicos e terapeutas respiratórios na Argentina foi de 63%. Falta de treinamento em metodologia científica e quantidade de leitura (< 6 artigos científicos por ano) foram identificados como independentemente associados com a falta de conhecimento sobre valores de p por parte dos participantes.

ABSTRACT Objective: To determine the prevalence of and risk factors for insufficient knowledge related to p-values among critical care physicians and respiratory therapists in Argentina. Methods: This cross-sectional online survey contained 25 questions about respondents' characteristics, self-perception and p-value knowledge (theory and practice). Descriptive and multivariable logistic regression analyses were conducted. Results: Three hundred seventy-six respondents were analyzed. Two hundred thirty-seven respondents (63.1%) did not know about p-values. According to the multivariable logistic regression analysis, a lack of training on scientific research methodology (adjusted OR 2.50; 95%CI 1.37 - 4.53; p = 0.003) and the amount of reading (< 6 scientific articles per year; adjusted OR 3.27; 95%CI 1.67 - 6.40; p = 0.001) were found to be independently associated with the respondents' lack of p-value knowledge. Conclusion: The prevalence of insufficient knowledge regarding p-values among critical care physicians and respiratory therapists in Argentina was 63%. A lack of training on scientific research methodology and the amount of reading (< 6 scientific articles per year) were found to be independently associated with the respondents' lack of p-value knowledge.

How to use χ2 test correctly——the analysis of a common risk difference for the data of a multiway table and the implementation of SAS software / 四川精神卫生

The purpose of this article was to introduce the risk rate difference analysis method of the g×2×2 table data and the calculation method based on the SAS software. The tasks that needed to be completed included the following two terms： first， the point estimation of the common risk rate difference and its confidence interval estimation； second， the test "whether the common risk rate difference was equal to 0". Among them， there were a total of 6 approaches for achieving the aforementioned first task； and three approaches for achieving the aforementioned second task. Based on the SAS software and an example， the article realized the point estimation， the confidence interval estimation and the hypothesis test of the common risk rate difference， respectively. Next， the SAS output results were explained and the statistical and professional conclusions were made.

Ahorro en los hogares de México: ¿importa el lugar de residencia? / Saving Profiles in Mexican Households. Does the Place of Residence Matter? / Poupança em famílias no México: o local de residência é importante?

En este artículo se analiza el perfil de ahorro de los hogares rurales y urbanos en México. A partir de la Encuesta Nacional de Ingresos y Gastos de los Hogares de 1994 a 2014 se construye un panel sintético y se estima un modelo semiparamétrico que permite identificar los perfiles por edades. Los resultados contrastan con la hipótesis del ciclo de vida, el perfil por edades no muestra una forma de U invertida, hay evidencia de mayor ahorro en las edades avanzadas. Los perfiles de ahorro son mayores en los hogares urbanos, en particular en aquellos con personas mayores y acceso a la salud.

This paper analyzes the saving profile of rural and urban Mexican households. Based on the National Survey of Household Income and Expenditure from 1994 to 2014, a synthetic panel is constructed and a semi-parametric model is estimated to identify profiles by age. Results show a contrast with the life cycle hypothesis. The age profile does not show an inverted U shape and there is evidence of greater savings in advanced ages. Saving profiles are higher in urban households, particularly for the elderly and regarding access to health.

Este artigo analisa o perfil de poupança de famílias rurais e urbanas no México. Com base na Pesquisa Nacional de Renda e Despesa Domiciliar de 1994 a 2014, é construído um painel sintético e estimado um modelo semiparamétrico que permite identificar os perfis por idade. Os resultados contrastam com a hipótese do ciclo de vida. O perfil da idade não apresenta a forma de U invertido e há evidências de maior economia em idades avançadas. Os perfis de poupança são mais elevados nos domicílios urbanos, especialmente naqueles com idosos e com acesso à saúde.

Multiple hypothesis testing in radiobiological omics study / 中华放射医学与防护杂志

With the development of high-throughput sequencing technology, the high-dimensional massive data obtained in omics study puts forward new requirements for statistical analysis. In this case, the traditional theory of single hypothesis testing is no longer applicable, and the issue of multiple hypothesis testing has received increasing attention. This paper introduced three commonly used error measures in multiple testing-family-wise error rate (FWER), false discovery rate (FDR), and positive false discovery rate (pFDR), and the control process in radiobiological omics data analysis, in order to provide a reference for statistical analysis of radiobiological data.

Educational Practice Based on Hypothesis-Driven Physical Examination / 医学教育

During the coronavirus pandemic, we focused on Hypothesis-Driven Physical Examination (HDPE), which is performed while considering physical examination and differential diagnosis as issues that can be learned without directly having contact with patients. We created HDPE scenarios with students who elected general medicine in Clinical Clerkship 2, and we implemented HDPE using that scenario on the last day of the clerkship. The scenario was created online and HDPE was conducted face-to-face. Students could learn correct medical examination techniques and manners through mutual learning. In addition, they could acquire communication and lifelong learning abilities through cooperative learning. We were able to enhance the learning effect through mutual learning that works on the students’ own intrinsic motivation in terms of both creating scenarios for the framework of cognitive apprenticeship and implementing HDPE.