Optimized Route for the Fabrication of MnAlC Permanent Magnets by Arc Melting.

The rare-earth-free MnAlC alloy is currently considered a very promising candidate for permanent magnet applications due to its high anisotropy field and relatively high saturation magnetization and Curie temperature, besides being a low-cost material. In this work, we presented a simple fabrication route that allows for obtaining a magnetically enhanced bulk τ-MnAlC magnet. In the fabrication process, an electric arc-melting method was carried out to melt ingots of MnAlC alloys. A two-step solution treatment at 1200 °C and 1100 °C allowed us to synthesize a pure room-temperature ε-MnAlC ingot that completely transformed into τ-MnAlC alloy, free of secondary phases, after an annealing treatment at 550 °C for 30 min. The Rietveld refinements and magnetization measurements demonstrated that the quenched process produces a phase-segregated ε-MnAlC alloy that is formed by two types of ε-phases due to local fluctuation of the Mn. Room-temperature hysteresis loops showed that our improved τ-MnAlC alloy exhibited a remanent magnetization of 42 Am2/kg, a coercive field of 0.2 T and a maximum energy product, (BH)max, of 6.07 kJ/m3, which is higher than those reported in previous works using a similar preparation route. Experimental evidence demonstrated that the synthesis of a pure room-temperature ε-MnAlC played an important role in the suppression of undesirable phases that deteriorate the permanent magnet properties of the τ-MnAlC. Finally, magnetic images recorded by Lorentz microscopy allowed us to observe the microstructure and magnetic domain walls of the optimized τ-MnAlC. The presence of magnetic contrasts in all the observed grains allowed us to confirm the high-quality ferromagnetic behavior of the system.

Ejercicios físicos terapéuticos domiciliarios en la atención a pacientes con fibromialgia durante la COVID-19 / Home therapeutic physical exercises in the care of patients with fibromyalgia during COVID-19

Introducción: El ejercicio físico sistemático constituye una herramienta indispensable para el tratamiento de los pacientes con fibromialgia, y más aún en la etapa de COVID-19. Objetivo: Constatar la eficacia de los ejercicios físicos terapéuticos domiciliarios en la atención a pacientes con fibromialgia durante la COVID-19. Métodos: Se realizó un prexperimento, con una muestra intencional de 20 pacientes con fibromialgia. Se utilizó el cuestionario de impacto de fibromialgia para conocer el impacto general de la enfermedad y la escala analógica visual del dolor para determinar la intensidad del dolor. Se conoció por medio de los exámenes físicos la condición física de los pacientes. Se aplicó la prueba no paramétrica de McNemar y Wilcoxon para identificar cambios producidos en los pacientes mediante la aplicación de ejercicios físicos terapéuticos domiciliarios. Resultados: El promedio de edad fue de 47,85 años, con predominio del sexo femenino (95,0 por ciento). Al inicio de la investigación las puntuaciones del cuestionario de impacto de fibromialgia determinaron que el 85,0 por ciento de los pacientes tenían un impacto moderado y severo de la enfermedad. La escala analógica visual del dolor evidenció que los pacientes padecían dolor moderado y severo. La evaluación de los exámenes físicos demostró que en su mayoría los pacientes tenían una condición física inadecuada. Después de implementado los ejercicios físicos terapéuticos domiciliarios se demostró una mejoría de los parámetros evaluados, evidenciado mediante la estadística inferencial a través de la prueba McNemar ya que los resultados estuvieron a un nivel inferior (p = 0,005). Los resultados de Z de Wilcoxon tuvieron una significación bilateral de 0,000. Conclusiones: Se evidenciaron cambios significativos en los pacientes con fibromialgia. Los ejercicios físicos terapéuticos domiciliarios fueron efectivos en los pacientes con fibromialgia durante el aislamiento por la COVID-19(AU)

Introduction: Systematic physical exercise constitutes an indispensable tool for the treatment of patients with fibromyalgia: and even more so in the COVID-19 stage. Objective: To verify the effectiveness of home therapeutic physical exercises in the care of patients with fibromyalgia during COVID-19. Methods: A pre-experiment was conducted with a purposive sample of 20 patients with fibromyalgia. A general characterization of the sample was performed. The Fibromyalgia Impact Questionnaire was used to know the general impact of the pathology and the Visual Analog Scale to determine the intensity of the patients' pain. Physical tests were used to determine the physical condition of the sample. The McNemar and Wilcoxon non-parametric test was applied to identify changes produced in the patients through the application of home therapeutic physical exercises. Results: The average age was 47.85 years with a predominance of the female sex (95.0 percent). At the beginning of the research, the Fibromyalgia Impact Questionnaire scores showed that 85.0 percent of the patients were in moderate and severe impact of the disease, as well as the Visual Analog Scale, which showed that the patients were in moderate and severe pain. The evaluation of the physical tests showed that most of the patients were in inadequate physical condition. After implementing the home therapeutic physical exercises, an improvement of the evaluated parameters was demonstrated, thus evidenced by the contracting of inferential statistics through McNemar since the results were at a lower level for p=0.005 and the Wilcoxon Z results resulted in a bilateral significance of 0.000. Conclusions: It is concluded that the results obtained evidenced significant changes in fibromyalgia patients, which can be said that home therapeutic physical exercises were effective in fibromyalgia patients during isolation by COVID-19(AU)

Return to exercise after COVID-19. Statement of the Mexican Society of Cardiology / Retorno al ejercicio después de COVID-19. Posicionamiento de la Sociedad Mexicana de Cardiología

The coronavirus disease 2019 (COVID-19) was declared a pandemic on March 11, 2020; one consequence has been the increase in sedentary lifestyle and reduction of sports activity. Exercise benefits the immune defense system especially in older adults; it is recommended to keep a distance of 1.5 meters between people, and if walking or jogging is carried out, the space must be up to 5 and 10 meters respectively. The reported cases are mostly mild up to 80% and can be critical in up to 4.7%; the risk factors are well known, hypertension, diabetes and previous heart disease. Severe or critical cases present as symptoms of acute respiratory distress syndrome, and in the case of cardiovascular disease, they mainly occur as myopericarditis, acute coronary syndromes, cardiogenic shock, thrombotic events, among others. Returning to exercise after recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is always recommended, however it will depend on the clinical picture what measures should be taken prior to its onset, and it is in moderate cases and especially in the severe ones where the evaluation and prescription prior to returning to exercise or sport should be guided by medical personnel experts in cardiopulmonary rehabilitation, especially in athletes.

La enfermedad por coronavirus 2019 (COVID-19) fue declarada pandemia el 11 de marzo de 2020; una consecuencia ha sido el incremento en el sedentarismo y la reducción de la actividad deportiva. El ejercicio beneficia el sistema inmunitario de defensa, especialmente en adultos mayores. Se recomienda guardar distancia de 1.5 metros entre personas, y si se realiza caminata o trote, el espacio debe ser de hasta 5 y 10 metros respectivamente. Los casos reportados son en su mayoría leves hasta en un 80%, y pueden ser críticos hasta en 4.7%; los factores de riesgo son bien conocidos: hipertensión, diabetes y enfermedad cardiaca previa. Los casos graves o críticos se presentan como cuadros de síndrome de distrés respiratorio agudo y ante afección cardiovascular cursan principalmente como miopericarditis, síndromes coronarios agudos, choque cardiogénico y eventos trombóticos, entre otros. El ejercicio después de la recuperación de infección por coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) siempre está recomendado, sin embargo, dependerá del cuadro clínico qué medidas se deben tomar previo a su inicio, y es en casos moderados y especialmente en los graves donde la evaluación y prescripción previa al retorno al ejercicio o deporte debe ser guiada por personal médico experto en rehabilitación cardiopulmonar, en especial en deportistas.

Increased chemerin serum levels in hyperandrogenic and normoandrogenic women from Argentina with polycystic ovary syndrome.

AIM: To assess serum chemerin levels and investigate the association of chemerin with the hyperandrogenic and normoandrogenic phenotypes of Polycystic Ovary Syndrome (PCOS) and with the metabolic status of the analyzed population. MATERIAL AND METHODS: A cross-sectional study was conducted on 106 women with PCOS and 60 healthy controls from Argentina. Patients were classified as showing a hyperandrogenic or normoandrogenic phenotype. Participants underwent anthropometric and clinical evaluation and markers of cardiovascular risk, insulin resistance, metabolic syndrome (MS), and serum chemerin levels were assessed. RESULTS: PCOS patients showed increased levels of chemerin. In adjusted models for age and body mass index (BMI), chemerin was associated with markers of metabolic status. The analysis of chemerin levels considering the cutoff values of BMI, homeostatic model of insulin sensitivity (HOMA-IR) and TG/HDL marker showed that PCOS patients always presented higher levels of chemerin than controls. PCOS group showed increased chemerin levels independently of the presence of MS. CONCLUSION: PCOS patients always showed increased levels of chemerin independently of their phenotype and presence of overweight, as well as higher levels of chemerin than controls when considering the cutoff values of HOMA-IR and TG/HDL. Therefore, argentine women with PCOS display increased chemerin levels independently of their metabolic or androgenic status.

Extractos de los documentos de posicionamientos y recomendaciones mexicanas en enfermedades cardiovasculares y COVID-19 / Excerpts from the documents of Mexican positions and recommendations in cardiovascular diseases and COVID-19

Resumen Se presentan las recomendaciones en las cuales la Sociedad Mexicana de Cardiología (SMC) en conjunto con la Asociación Nacional de Cardiólogos de México (ANCAM), así como diferentes asociaciones médicas mexicanas vinculadas con la cardiología, después de una revisión y análisis exhaustivo y consensuado sobre los tópicos relacionados con las enfermedades cardiovasculares en la pandemia de COVID-19, se analizan posturas científicas y se dan recomendaciones responsables sobre medidas generales a los pacientes, con cuidados personales, alimentación saludable, actividad física regular, acciones en caso de paro cardiorrespiratorio, la protección del paciente y del personal de salud así como las indicaciones precisas en el uso de la imagen cardiovascular no invasiva, la prescripción de medicamentos, cuidados en tópicos específicos como en la hipertensión arterial sistémica, insuficiencia cardiaca, arritmias y síndromes coronarios agudos, además de hacer énfasis en los procedimientos de electrofisiología, intervencionismo, cirugía cardiaca y en la rehabilitación cardiaca. El interés principal es brindar a la comunidad médica una orientación general sobre el quehacer en la práctica cotidiana y pacientes con enfermedades cardiovasculares en el escenario esta crisis epidemiológica sin precedentes de COVID-19.

Abstract The recommendations in which the Mexican Society of Cardiology (SMC) in conjunction with the National Association of Cardiologists of Mexico (ANCAM) as well as different Mexican medical associations linked to cardiology are presented, after a comprehensive and consensual review and analysis of the topics related to cardiovascular diseases in the COVID-19 pandemic. Scientific positions are analyzed and responsible recommendations on general measures are given to patients, with personal care, healthy eating, regular physical activity, actions in case of cardio-respiratory arrest, protection of the patient and health personnel as well as precise indications in the use of non-invasive cardiovascular imaging, prescription of medications, care in specific topics such as systemic arterial hypertension, heart failure, arrhythmias and acute coronary syndromes, in addition to emphasizing electrophysiology, interventionism, cardiac surgery and in cardiac rehabilitation. The main interest is to provide the medical community with a general orientation on what to do in daily practice and patients with cardiovascular diseases in the setting of this unprecedented epidemiological crisis of COVID-19.

Lipid Accumulation Product (LAP) and Visceral Adiposity Index (VAI) as Markers of Insulin Resistance and Metabolic Associated Disturbances in Young Argentine Women with Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is an endocrine disorder. PCOS women are at high risk of developing insulin resistance (IR) and cardiovascular disorders since young age. We aimed to study the reliability of lipid accumulation product (LAP) and visceral adiposity index (VAI) as markers of metabolic disturbances (MD) associated with IR in young reproductive aged PCOS patients. We also evaluated the association between LAP and VAI and the presence of hyperandrogenism. In a cross-sectional study, 110 PCOS patients and 88 control women (18-35 years old) were recruited. PCOS patients were divided into 2 groups, as hyperandrogenic and non-hyperandrogenic considering the signs of hyperandrogenism (clinical or biochemical). Anthropometric measurements were taken and blood samples collected. Metabolic and anthropometric characteristics and their association with IR and associated MD were evaluated and LAP and VAI were calculated. LAP and VAI were compared with TC/HDL-c and TG/HDL-c to define the best markers of MD in this population. Independently of the phenotype, young PCOS patients showed high IR and dyslipidemia. Both LAP and VAI showed to be more effective markers to assess MD and IR in these young women than TG/HDL-c or TC/HDL-c [cut-off values: LAP: 18.24 (sensitivity: 81.43% specificity: 73.49%), positive predictive value (PPV): 75.0%, negative predictive value (NPV): 77.27%, VAI: 2.19 (sensitivity: 81.16% specificity: 72.15% PPV: 74.65% NPV: 72.22%)]. LAP and VAI are representative markers to assess MD associated with IR in young PCOS patients. All PCOS patients, independently of their androgenic condition, showed high metabolic risk.

Síndrome de ovario poliquístico: fenotipos y enfermedad cardiovascular / Polycystic ovary syndrome: Phenotypes and cardiovascular disease

Introducción: El síndrome de ovario poliquístico (SOP) es una endocrinopatía que afecta a mujeres en edad reproductiva, frecuentemente asociado a insulinorresistencia (IR) y riesgo cardiovascular (RCV). El criterio de Rotterdam distingue 4 fenotipos: 3 presentan hiperandrogenismo clínico y/o bioquímico (HA) y uno es normo-androgénico (NHA). Por ser un síndrome heterogéneo, es necesario identificar a las pacientes con mayor RCV. Dos nuevos marcadores han sido propuestos para evaluarlo: el índice de adiposidad abdominal (VAI) y el producto de acumulación lipídica (LAP). Objetivo: Evaluar los marcadores LAP y VAI como predictores de IR y su correlación con los parámetros de RCV en relación con los fenotipos SOP. Metodología: Se estudió a 130 pacientes con SOP entre 18 y 36 años, clasificadas en 2 grupos: HA y NHA según la presencia de hiperandrogenismo clínico y/o bioquímico. Se evaluaron parámetros de RCV según ATP III: circunferencia de cintura (CC), glucemia, HDL, triglicéridos (TG) y presión arterial. Se calcularon: LAP = (CC [cm] - 58) * TG (mmol/l) y VAI = (CC [cm]/[36,58 + (1,89 * IMC [kg/m²]] * [TG [mg/dl]/0,81] * [1,52/HDL-c [mg/dl]]). Se realizaron curvas ROC/área bajo la curva para establecer valores de corte de LAP y VAI para la identificación de IR, análisis de correlación con parámetros de RCV y de las diferencias entre fenotipos, tomando como significativo p < 0,05. Resultados: Los valores de corte establecidos para definir IR fueron de 14,02 para LAP (especificidad: 93,22%; sensibilidad: 93,94%) y de 2,17 para VAI (especificidad: 91,38%; sensibilidad: 87,88). Dichos marcadores correlacionaron con marcadores de IR (HOMA-IR, QUICKI e índice glucosa/insulina) y presentaron una correlación positiva con TG, CC y negativa con HDL. El análisis entre fenotipos no reveló diferencias en la presencia de SM, IR o factores de RCV. Conclusión: LAP y VAI serían buenos predictores de IR y RCV asociado en pacientes jóvenes con SOP. El análisis de los parámetros entre fenotipos HA y NHA indica que ambos presentan similar riesgo metabólico y de desarrollar enfermedad cardiovascular.

Introduction: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder affecting women of reproductive age. It is associated with insulin resistance (IR) and high cardiovascular risk (CVR). According to the Rotterdam consensus, four PCOS phenotypes could be established: three with clinical and/or biochemical hyperandrogenism (HA), and one non-hyperandrogenic (NHA). It is necessary to identify which of these patients are at risk of metabolic disturbances and CVR. Two indexes: lipid accumulation product (LAP) and visceral adiposity index (VAI) have been suggested as reliable markers of IR and CVR in PCOS. Objective: The present study aims to assess the reliability of LAP and VAI as IR markers in a young local population of PCOS patients. Their association with CVR parameters is also evaluated. Methodology: LAP and VAI were calculated in 130 PCOS patients. The PCOS patients were divided in two groups as HA and NHA, taking into account the signs of hyperandrogenism (clinical or biochemical). An evaluation was also made of the metabolic and anthropometric characteristics of the population and their association with CVR and IR. Results: Both LAP and VAI showed to be effective markers to asses CVR and IR in these PCOS women (cutoff values: LAP: 14.02 (sensitivity: 93.94% specificity: 93.22%) VAI: 2.17 (sensitivity: 87.88% specificity: 91.38%). There was a positive correlation of both markers with abdominal circumference and triglycerides (TG), and negative with HDL-cholesterol. The risk of IR and metabolic disturbances was similar in both phenotypes (NHA versus HA). Conclusion: Our data show that both LAP and VAI are representative markers for assessing IR and associated CVR in PCOS patients. These results also suggest that the NHA phenotype in the population studied shows the same risk of metabolic disturbances and cardiovascular disease when compared to HA phenotypes.

Low dose of bisphenol A impairs the reproductive axis of prepuberal male rats.

The objective of the present work was to study the effect of a low dose of bisphenol A (BPA), on the reproductive axis of prepuberal male rats exposed to the endocrine disruptor (ED) during gestation and lactation period. Wistar-mated rats were treated with either 0.1 % ethanol or BPA in their drinking water until their offspring were weaned at the age of 21 days. The estimated average dose of exposure to dams was approximately 3 µg/kg/day of BPA. The pups were sacrificed on the 35th day of life. Body weight was measured during the development and at the moment of the sacrifice; testicular and seminal vesicles weight and their respective relative weights were also measured. LH, FSH and testosterone were determined and histological studies of testicular tissue were also performed. Body weight at the moment of the sacrifice was significantly higher in the group exposed to BPA; testicular weight decreased significantly; seminal vesicles weight and relative weights of testes and seminal vesicles were not modified by treatment. LH and FSH serum levels increased significantly after treatment, meanwhile testosterone showed no significant changes. Histological studies showed the lumen of seminal tubes reduced by the presence of immature cells of the spermatic lineage. Our results suggest that pre- and early postnatal exposure to a low dose of BPA disrupts the normal function of the reproductive axis in prepuberal male rats. The effects of the ED may be exerted at different levels of the axis and may be dependent on the dose, manner of administration, and the moment of exposure to the disruptor.