PCM-based hybrid thermal management system for photovoltaic modules: A comparative analysis.

Proper temperature regulation of photovoltaic (PV) modules increases their performance. Among various cooling techniques, phase change materials (PCMs) represent an effective thermal management route, thanks to their large latent heat at constant temperatures. Radiative cooling (RC) is also recently explored as a passive option for PV temperature regulation. In this paper, a heat sink (HS), phase change materials, and radiative cooling are integrated with photovoltaic modules to achieve low and uniform temperature distribution along the PV module and improved performance. Eight different combinations are considered for the proposed system, including HS, PCM, and RC, and their various combinations. The PCM is selected according to the environmental conditions of the selected location. A comprehensive 2-D model is developed and analyzed in COMSOL-Multiphysics software by solving the governing equations using the finite element method. The performance analysis is carried out for the climatic conditions of the Atacama Desert, having high solar radiation and ambient temperature. The effects of PCM height, ambient temperature, wind velocity, and solar radiation on the performance of the proposed system are studied. The performance of eight different configurations is also compared. The maximum reductions in PV temperature, maximum PV power, and a minimum drop in PV conversion efficiency are observed to be 22 oC, 152 W, and 14% using a combined heat sink and radiative cooling systems, among all other configurations. The findings of this study can be used to select the best PV cooling method among different configurations.

Bibliometría y mapeo de redes de la producción científica internacional de Cuba sobre ataxias (1993-2020) / Bibliometrics and network mapping of Cuban international scientific production on ataxias (1993-2020)

El objetivo del estudio fue caracterizar el potencial investigador cubano en el ámbito de las ataxias y su evolución temporal. Se realizó una búsqueda en la base de datos Web of Science y se obtuvieron todos los documentos publicados entre 1993 y 2020. Se aplicaron indicadores bibliométricos para explorar la producción, dispersión, distribución y crecimiento anual de los documentos (ley de Price, ley de Lotka, índice de transitoriedad y modelo de Bradford). Se calculó el índice de participación y colaboración de países e instituciones y, por cartografía bibliométrica, se exploraron las redes de coocurrencia de los términos más utilizados. La producción científica de Cuba sobre ataxias hereditarias es alta (219 documentos) y se ajusta a un crecimiento lineal (r= 0,7580). El período estudiado concentra el 47,95 por ciento de los registros con un ritmo anual de publicaciones del 6,6 por ciento y tiempo de duplicidad de 10,8 años. El total de citas fue de 3807 (índice medio: 131,27; índice -h: 31). Se concluye que el crecimiento de la literatura científica cubana sobre ataxias fue lineal para el período estudiado, lo que confirma el incumplimiento de la ley de Price de crecimiento de la literatura científica. El estudio también corrobora la importante red de integración y cooperación internacional entre los diferentes autores y la interdisciplinariedad de los trabajos, evidencia del éxito del Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias (CIRAH), al planificar una estrategia de colaboración científica con objetivos definidos(AU)

The objective of this study was to characterize the Cuban research potential in the field of ataxias and its temporal evolution. A search was carried out in the Web of Science database and all the documents published from 1993 to 2020 were retrieved. Bibliometric indicators were applied to explore the production, dispersion, distribution and annual growth of the documents (Price's law, Lotka's law, transience index and Bradford model). The participation and collaboration index of countries and institutions was calculated and, through bibliometric cartography, the co-occurrence networks of the most used terms were explored. The Cuban scientific production on hereditary ataxias is high (219 documents) and it adjusts to a linear growth (r = 0.7580). The period studied concentrates 47.95percent of the records with an annual publication rate of 6.6percent and 10.8 years' duplication time. The total number of citations was 3807 (mean index: 131.27; h-index: 31). Growth of the Cuban scientific literature on ataxias was concluded to be linear for the period studied, which confirms the non-compliance with Price's law of growth of scientific literature. The study also corroborates the important network of integration and international cooperation among the different authors and the interdisciplinarity of the papers, marking the success of the Center for Research and Rehabilitation of Hereditary Ataxias (CIRAH), when planning a strategy of scientific collaboration with objectives defined(AU)

The limit of physiological adaptation of the right ventricle to endurance training / El límite de la adaptación fisiológica del ventrículo derecho al entrenamiento de resistencia / O limite da adaptação fisiológica do ventrículo direito ao treino de resistência

The study aims to conduct a review of right ventricle, measured by echocardiography or magnetic resonance imaging, in athletes with high dynamic component and moderate static, the limit of the physiological adaptation. A search was carried out in the Medline database up to the end of 2017. This study showed that the mean values for the different measurements of the right ventricle in athletes are significantly greater than that of sedentary controls. In two of the 12 studies that analyzed mean diameter of the right ventricle in apical 4C, including 1477 endurance athletes and 498 controls, with high heterogeneity. Endurance athletes presented significantly higher longitudinal diameter of the RV in apical absolutes scores compared to control. The end diastolic volume and end systolic volume measured by magnetic resonance imaging, showed a significant standardized mean difference favoring athletes with a moderate heterogeneity.(AU)

El estudio tiene como objetivo realizar una revisión del ventrículo derecho, medido por ecocardiografía o resonancia magnética, en deportistas con alto componente dinámico y estático moderado, el límite de la adaptación fisiológica. Se realizó una búsqueda en la base de datos Medline hasta finales de 2017. Este estudio mostró que los valores medios de las diferentes mediciones del ventrículo derecho en los deportistas son significativamente mayores que los de los controles sedentarios. En dos de los 12 estudios que analizaron el diámetro medio del ventrículo derecho en apical 4C, incluyendo 1477 atletas de resistencia y 498 controles, con alta heterogeneidad. Los atletas de resistencia presentaron un diámetro longitudinal del VD en absolutas apicales significativamente mayor en comparación con los controles. El volumen diastólico final y el volumen sistólico final medidos por resonancia magnética, mostraron una diferencia media estandarizada significativa a favor de los atletas con una heterogeneidad moderada.(AU)

O estudo visa conduzir uma revisão do ventrículo direito, medido por ecocardiografia ou ressonância magnética, em atletas com elevada componente dinâmica e estática moderada, o limite da adaptação fisiológica. Foi realizada uma pesquisa na base de dados Medline até ao final de 2017. Este estudo mostrou que os valores médios das diferentes medidas do ventrículo direito em atletas são significativamente superiores aos dos controlos sedentários. Em dois dos 12 estudos que analisaram o diâmetro médio do ventrículo direito em 4C apical, incluindo 1477 atletas de endurance e 498 controlos, com elevada heterogeneidade. Os atletas de resistência apresentaram um diâmetro longitudinal do VD significativamente mais elevado nas pontuações absolutas apicais, em comparação com os controlos. O volume diastólico final e o volume sistólico final medido por ressonância magnética, mostraram uma diferença média padronizada significativa, favorecendo os atletas com uma heterogeneidade moderada.(AU)

Multifocal contact lenses: A bibliometric study

Purpose: To analyze the state of scientific publications in multifocal contact lenses field through a bibliometric study.Methods: The database used to carry out the study was SCOPUS and contained the descriptors “multifocal contact lens”, “bifocal contact lenses”, “progressive contact lenses” and “presbyopia contact lenses”, limited to the fields of title, keywords and abstract. The indicators applied in this research were: doubling time and annual growth rate, Price’s transience index, Lotka’s law of scientific productivity, and Bradford’s zones.Results: A total of 346 articles were published between 1960 and 2019. The growth in the number of publications matches the exponential adjustment slightly better (R = 0.53). The duplication time was 13.2 years. The productivity level is focused on articles with an average number of authors of just 2.06 per article. The Bradford core was formed by two journals, Optometry and Vision Science and Eye and Contact Lens.Conclusions: Research on multifocal contact lenses has exponential growth, without evidence of having reached a saturation point. The main countries in scientific production in this field are the United States and Australia. (AU)

Multifocal contact lenses: A bibliometric study.

PURPOSE: To analyze the state of scientific publications in multifocal contact lenses field through a bibliometric study. METHODS: The database used to carry out the study was SCOPUS and contained the descriptors "multifocal contact lens", "bifocal contact lenses", "progressive contact lenses" and "presbyopia contact lenses", limited to the fields of title, keywords and abstract. The indicators applied in this research were: doubling time and annual growth rate, Price's transience index, Lotka's law of scientific productivity, and Bradford's zones. RESULTS: A total of 346 articles were published between 1960 and 2019. The growth in the number of publications matches the exponential adjustment slightly better (R = 0.53). The duplication time was 13.2 years. The productivity level is focused on articles with an average number of authors of just 2.06 per article. The Bradford core was formed by two journals, Optometry and Vision Science and Eye and Contact Lens. CONCLUSIONS: Research on multifocal contact lenses has exponential growth, without evidence of having reached a saturation point. The main countries in scientific production in this field are the United States and Australia.

Perfil antropométrico comparativo entre jugadores juveniles de rugby de élite / Comparative anthropometric profile between of elite rugby union youth players

Introducción: La evaluación antropométrica de los deportistas es necesaria para optimizar la identificación y el desarrollo delos jugadores. Nuestro objetivo es describir las características antropométricas por posición en los jugadores de las seleccionesde rugby XV Sub18 y Sub20 durante dos temporadas.Material y método: A 152 jugadores de las selecciones de rugby XV Sub18 y Sub20 de España se les midió la estatura, masacorporal, pliegues cutáneos, porcentaje de tejido graso, masa muscular esquelética (MME), masa mineral ósea (MMO) y soma-totipo durante las temporadas 2015-2016 y 2016-2017. Se calculó el promedio y la desviación estándar para cada selección,grupo y posición. Se realizó el análisis de U de Mann-Whitney para comparar entre selecciones y por grupos. Para compararentre posiciones se utilizó la prueba de Kruskal-Wallis. Resultados: Los jugadores agrupados como delanteros presentan mayor masa corporal, estatura, porcentaje de tejido graso,MME y MMO que los tres cuartos (p <0,05). Los jugadores que ocupan la posición de piliers presentan mayor porcentaje detejido graso (p <0,05) y los que ocupan la posición de segunda línea son los de mayor estatura (p <0,05). Conclusiones: Los jugadores de élite en España Sub20 presentan mayor masa corporal, porcentaje de tejido graso y MMEque los jugadores élite de España Sub18. Los jugadores agrupados como delanteros de nivel élite en España Sub18 y Sub20presentan mayor masa corporal, estatura, porcentaje de tejido graso, MME y MMO que los jugadores agrupados como trescuartos. La posición con mayor masa corporal y porcentaje de tejido graso es la de piliers en los jugadores de élite de España en las categorías Sub18 y Sub20. Los jugadores de nivel élite que ocupan la posición de segundas líneas son los de mayorestatura en España en las categorías Sub18 y Sub20.(AU)

Background: Anthropometric evaluation of athletes is necessary to optimize talent identification and player development.The aim was to describe the anthropometric characteristics of national under-18 and under-20 rugby team by field positionsin two season. Material and method: 152 players of under-18 and under-20 rugby teams were to measured mass, stature, skinfolds, percentage body fat, skeletal muscle mass, bone mineral and somatype between 2015-2016 and 2016-2017 season. Mean andstandard deviation were calculated for each national team, groups and positional. The Mann-Whitney U test were performedto investigate differences between national team and by groups. The Kruskal-Wallis test was performed to investigate differences between positional. Results: The foward units were heavier, taller and had a larger percentage body fat and skeletal muscle mass than back units(p <0.05). The props had a larger percentage body fat (p <0.05) and the seconds row were taller (p <0.05).Conclusions: The elite players of under-20 in Spain are heavier and have a larger percentage body fat and skeletal musclemass than elite players of under-18. The foward units are heavier, taller and have a larger percentage body fat, skeletal musclemass and bone mineral tan back units. The props are heavier positional and have larger percentage body fat. The secondsrow are taller positional.(AU)

Bibliometric study of scientific research on optometric visual therapy / Estudio bibliométrico de investigación científica sobre terapia visual optométrica

PURPOSE: To analyze scientific research in the field of visual therapy through a bibliometric study. METHODS: The database used in this bibliometric study was SCOPUS, the largest abstract and citation database of peer-reviewed literature, covering scientific journals, books, and conference proceedings. Using remote downloading techniques, articles published between 1946 and 2017 were selected by entering the main descriptors: "optometric vis* training", "optometric vis* therapy", "vis* therapy", "vis* training" limited to the title, key words and/or abstract. We applied the following bibliometric indicators: Price's index, doubling time and annual growth rate, Price's transience index, Lotka's Law, h factor, and Bradford's zones. RESULTS: The authors retrieved 294 original articles from the temporal interval 1946-2017 (articles, reviews, letters to the director, etc.), discarding 15 of them for not meeting the study requirements. Annual growth rate was 39.62%, the timeframe 1987-1983 containing the most number of documents. United States was the country with the highest production, with more than 60% of the records. The most productive institutions are State University of New York System, SUNY State College of Optometry, and Southern California College of Optometry. Classification of authors based on productivity is strongly concentrated in small producers, with a transient index of 80.53. The total number of authors was 488, representing a co-authorship index of 1.75. CONCLUSION: Bibliometric studies have become essential tools for assessing scientific publications

OBJETIVO: Analizar la investigación científica en el campo de la terapia visual, a través de un estudio bibliométrico. MÉTODOS: La base de datos utilizada en este estudio bibliométrico fue SCOPUS, la mayor base de datos de resúmenes y citas de la literatura revisada por pares, que cubre publicaciones científicas, libros y actas de conferencias. Utilizando técnicas de descargas remotas, se seleccionaron los artículos publicados entre 1946 y 2017 introduciendo los descriptores principales: "optometric vis* training", "optometric vis* therapy", "vis* therapy", "vis* training" limitados al título, las palabras clave y/o el resumen. Aplicamos los siguientes indicadores bibliométricos: índice de Price, tiempo de duplicado y tasa de crecimiento anual, índice de transitoriedad de Price, Ley de Lotka, factor h, y zonas de Bradford. RESULTADOS: Los autores recuperaron 294 artículos originales del intervalo temporal 1946-2017 (artículos, revisiones, cartas al director, etc.), descartando 15 de ellos por no cumplir los requisitos del estudio. La tasa de crecimiento anual fue del 39,62%, conteniendo el marco temporal 1987-1983 el mayor número de documentos. Estados Unidos fue el país más productivo, con más del 60% de los registros. Las instituciones más productivas son: State University of New York System, SUNY State College of Optometry, y Southern California College of Optometry. La clasificación de los autores basada en la productividad está fuertemente concentrada en pequeños productores, con un índice de transitoriedad de 80,53. El número total de autores fue de 488, lo cual representa un índice de co-autoría de 1,75. CONCLUSIÓN: Los estudios bibliométricos han resultado ser herramientas esenciales para evaluar las publicaciones científicas

Bibliometric study of scientific research on optometric visual therapy.

PURPOSE: To analyze scientific research in the field of visual therapy through a bibliometric study. METHODS: The database used in this bibliometric study was SCOPUS, the largest abstract and citation database of peer-reviewed literature, covering scientific journals, books, and conference proceedings. Using remote downloading techniques, articles published between 1946 and 2017 were selected by entering the main descriptors: "optometric vis* training", "optometric vis* therapy", "vis* therapy", "vis* training" limited to the title, key words and/or abstract. We applied the following bibliometric indicators: Price's index, doubling time and annual growth rate, Price's transience index, Lotka's Law, h factor, and Bradford's zones. RESULTS: The authors retrieved 294 original articles from the temporal interval 1946-2017 (articles, reviews, letters to the director, etc.), discarding 15 of them for not meeting the study requirements. Annual growth rate was 39.62%, the timeframe 1987-1983 containing the most number of documents. United States was the country with the highest production, with more than 60% of the records. The most productive institutions are State University of New York System, SUNY State College of Optometry, and Southern California College of Optometry. Classification of authors based on productivity is strongly concentrated in small producers, with a transient index of 80.53. The total number of authors was 488, representing a co-authorship index of 1.75. CONCLUSION: Bibliometric studies have become essential tools for assessing scientific publications.

Disadvantages of Automated Respiratory Gas Exchange Analyzers.

The use of automated gas exchange analysis systems in exercise studies is common throughout the industrialized world and are frequently used in sports medicine laboratories for the measurement of maximal oxygen uptake (VO2max), as an integrative parameter that allows the physical condition to be assessed, in spite of its limitations. Actually, the fundamental principles behind the measurement of respiratory gas exchange (RGE) have not changed for a century. It was used a manual Douglas bag method together with separate chemical analyses. The need for faster and more efficient techniques, has conditioned the traditional procedures and determined the emergence of automated systems. However, the validity and reliability of all these different systems is not well known. The common features associates with these systems, also have disadvantages that must be evaluated at the time of the acquisition of an automated equipment: (1) regular quality control checks, which entails other added economic costs, (2) the validity and reliability of the results, which it is necessary to verify, and (3) the user does not know the equations that determine the values of oxygen consumption and carbon dioxide production. This work aims to clarify the disadvantages of these automated systems. At maximum intensities, the variation of VO2max or VO2peak can be very significant in athletes and even more relevant in sick people undergoing a training program. Therefore, considerable care is needed when comparing RGE data with automated systems. NEW AND NOTEWORTHY: Actually, stress tests are more conveniently performed with automated systems. It is necessary to examine the validity and reliability of automated respiratory gas exchange systems. The algorithms incorporated in the software, apart from being a "mystery," show differences with respect to the data provided.

Peripapillary retinal nerve fibre layer thinning in genetic generalized epilepsy.

PURPOSE: The purpose of this study was to compare the peripapillary retinal nerve fibre layer (RNFL) between patients with genetic generalized epilepsy (GGE) and healthy controls. METHODS: This prospective observational study was conducted on adults aged 18-60 years. The study group comprised 26 consecutive patients who met the inclusion criteria and 26 healthy age- and sex-matched healthy adults. Peripapillary RNFL thickness was measured by spectral domain optical coherence tomography. RESULTS: The average peripapillary RNFL thickness was significantly thinner for GGE patients (98.61 µm) than for healthy controls (104.77 µm) (p = 0.016). Similar results were obtained for the left eye. The peripapillary RFNL thickness of all quadrants was lower for GGE patients than for healthy controls, but it was significant only in the superior (p = 0.009) and inferior (p = 0.024) quadrants for both eyes. CONCLUSIONS: Our results suggest that the peripapillary RNFL is significantly thinner in GGE patients than in healthy participants. We concluded that this microstructural feature might be an intrinsic feature of GGE.

¿Realmente estudiamos al deportista de resistencia de élite? / Do we really study the elite endurance athlete?

No disponible

Cardio-respiratory values during recovery from exercise in soccer Spanish leagues.

OBJECTIVE: In this cross-sectional study, we compared Spanish division one (n = 114) and division two (n = 80) soccer players in terms of their cardio-respiratory response during recovery following a maximum laboratory effort test. APPROACH: Following the maximum laboratory effort protocol, we measured oxygen consumption ([Formula: see text]), heart rate (HR), and ventilation ([Formula: see text]) during recovery. MAIN RESULTS: Over the first 60 s of recovery, no significant differences were seen in either [Formula: see text] (28.7 versus 28.3 ml/kg/m, in division one and two players, respectively), HR, or [Formula: see text] (p > 0.05). After 90 s, however, significant differences appeared between the players of the two divisions (p < 0.01), although not among playing positions. Significant differences in [Formula: see text] (21.1 versus 26.0 ml/kg/m, in division one and two players, respectively) and HR were still apparent at 180 s into the recovery period. The change in professional soccer players' cardio-respiratory values over the recovery period following maximum effort are independent of the position played, but are associated with the division in which a player competes. Second division players show significantly higher [Formula: see text] and HR values than first division players at 180 s into the recovery period. SIGNIFICANCE: These differences might influence performance in soccer and in other athletes whose sports require intermittent bouts of maximum effort and consequently times to repeat high-intensity efforts as short as possible.

Bibliometric Study of Scientific Research on Scleral Lenses.

PURPOSE: To analyze the state of scientific publications in the field of scleral lenses applying a bibliometric study. METHODS: The database used in this bibliometric study was SCOPUS, the largest abstract and citation database of peer-reviewed literature: scientific journals, books, and conference proceedings. Using remote download techniques, articles published between 1962 (year of first registrations) and 2015 were selected by entering the main descriptors: "scleral contact lenses" and "scleral lenses," limiting the field for the article, keywords, and abstract, linked with the OR tab. We applied the following bibliometric indicators: Price index, doubling time and annual growth rate, Price transience index, Lotka law of scientific productivity, and Bradford zones. RESULTS: The authors recovered 361 contributions (articles, reviews, letters to the editor, etc.) for 1962 to 2016. The distribution for five-year periods shows a significant increase in 2012 to 2016, with a growth of 222.22% in comparison with the previous period 2012 to 2016. The countries with the highest production are the United states with 135 contributions, United Kingdom with 46, and India with 19. The most productive institutions are Harvard Medical school, Boston Foundation for Sight, and Moorfields Eye Hospital National Health Service Foundation Trust. Classification of authors based on productivity is strongly concentrated in small producers, with a transient index of 59.03. The total number of authors is 891, representing a coauthor index of 2.47 for the 361 documents retrieved. The authors with the highest productivity are Kenneth W. Pullum, Perry Rosenthal, and Deborah S. Jacobs, with an h-index between 12 and 19 documents. The number of documents published on scleral lenses shows a significant increase in the last 5 years, and currently, they represent only 1.44% of all publications on contact lenses. CONCLUSIONS: Bibliometric studies have become essential tools for evaluating scientific activity, allowing an overview of the growth, size, and distribution of scientific literature associated with a particular discipline.

Adaptación de la aorta al entrenamiento. Perspectiva fisiológica / Adaptation of the aorta to training. Physiological perspective

La función de amortiguación de las oscilaciones de la presión de la sangre hace de la aorta una «prolongación» de la función ventricular sistólica. Esta función se pone aún más de manifiesto durante el ejercicio de resistencia, durante el cual se produce un incremento del índice de eyección de unas 4 veces los valores de reposo. De la misma manera que a consecuencia del entrenamiento se produce una adaptación de la morfología cardiaca, la aorta experimenta una modificación de su estructura que permite una mejor función amortiguadora. Los deportistas que mayor grado de adaptación pueden experimentar, tanto de las cavidades cardiacas como de la aorta, son aquellos que demandan una elevada exigencia cardiovascular, alto componente dinámico y moderado estático. En seres humanos, mediante medidas incruentas (ecocardiografía, resonancia magnética, fundamentalmente), se ha demostrado un incremento del tamaño de la aorta en los deportistas con mayor exigencia cardiovascular

The damping of the blood pressure oscillations makes the aorta an ‘‘extension’’ of the ventricular systolic function. This function is even more evident during endurance exercise, with an increase in the ejection index of 4 times the resting values. Similarly, as a result of training, an adaptation occurs in cardiac morphology, in which the aorta undergoes a change in its structure that allows for better damping function. Athletes that adapt more may experience both of the heart chambers and the aorta, are those who demand a high cardiovascular stress, a high dynamic component and moderate static component. By using non-invasive measurements in humans (mainly echocardiography and MRI), the size of the aorta has been shown to increase in athletes with greater cardiovascular demands

Limits of ventricular function: from athlete's heart to a failing heart.

The interest in the study of ventricular function has grown considerably in the last decades. In this review, we analyse the extreme values of ventricular function as obtained with Doppler echocardiography. We mainly focus on the parameters that have been used throughout the history of Doppler echocardiography to assess left ventricular (LV) systolic and diastolic function. The 'athlete's heart' would be the highest expression of ventricular function whereas its lowest expression is represented by the failing heart, independently from the original aetiology leading to this condition. There are, however, morphological similarities (dilation and hypertrophy) between the athlete's and the failing heart, which emerge as physiological and pathophysiological adaptations, respectively. The introduction of new assessment techniques, specifically speckle tracking, may provide new insight into the properties that determine ventricular filling, specifically left ventricular twisting. The concept of ventricular function must be always considered, although it may not be always possible to distinguish the normal heart of sedentary individuals from that of highly trained hearts based solely on echocardiographic or basic studies.

Changes in the severity of aortic regurgitation at peak effort during exercise.

BACKGROUND: Chronic aortic regurgitation can be well tolerated for a long time. Some patients with normal ventricular function can even reach high levels of sporting performance. How the severity of regurgitation may change during exercise, however, is little known, although some studies suggest it diminishes. The present work examines, during exercise, the functional capacity, ventricular function, and regurgitation fraction (RF) in asymptomatic subjects with moderate or severe aortic regurgitation with preserved ejection fraction. METHODS: The study subjects (n=32; 23 men, 9 women) were patients referred to our echocardiography laboratory with moderate or severe aortic regurgitation, preserved left ventricular systolic function, and sinus rhythm into NYHA functional class I. All underwent transthoracic echocardiography at rest and at peak effort during an exercise protocol involving an inclined cycloergometer. Left atrial and ventricular volume indices were recorded, along with diastolic and systolic function, cardiac index, peripheral resistance, and RF. RESULTS: The mean age of the subjects was 43.8±18.2years; 59% suffered moderate regurgitation, 41% severe aortic regurgitation, and 84% had a dilated left ventricle. All subjects managed exercise loads adequate for their age. Peak effort was associated with a significant reduction (mean 44.5% [range 10-95%]) in the RF (21.8±13.2 vs. 39.3%±14.7% at rest; p=0.0001). The absolute reduction in the RF at peak effort was greater among the subjects with severe aortic regurgitation (21.2% vs. 13.3% in those with moderate regurgitation; p=0.018). CONCLUSIONS: The RF becomes smaller during exercise in asymptomatic subjects with moderate or severe aortic regurgitation and preserved ventricular function.

La enseñanza de la fisiología humana en el Instituto Nacional de Educación Física de Madrid: una experiencia de 30 años / Teaching human physiology in National Institute of Physical Educacion Madrid: 30 years experience

Este trabajo pretende presentar la experiencia docente en una disciplina de los estudios de INEF: la fisiología humana. A lo largo de 28 promociones he intentado contribuir a la formación de más de 9.500 alumnos en esta difícil disciplina de la carrera. Lo más notable de los resultados es el índice de abandono tan considerable, que alcanza el valor medio del 48%. Este abandono, indicado por el número de alumnos no presentados y la tasa de absentismo (tasa absentismo = número de alumnos no presentados/número total de alumnos), ha experimentado un aumento considerable entre la primera promoción (1986-1987) y la promoción número 13 (1997-1998) desde que empecé a impartir esta asignatura. Posteriormente, la tasa de absentismo ha tendido a una cierta estabilización. Una postura crítica de cualquier profesor determina la necesidad de realizar un análisis de una tasa de absentismo tan considerable. El elevado valor medio (84%) de la tasa de éxito (tasa de éxito = número de alumnos que superaron la asignatura/número total de alumnos) a lo largo de las 28 promociones indica que el problema del abandono no radica en el profesor. Entiendo que la elevada tasa de absentismo radica en una serie de causas interrelacionadas como son: 1) la formación previa del alumnado, 2) la dificultad de la fisiología humana, 3) la propia esencia de la carrera y 4) la forma reflexiva de entender la fisiología humana como base para la comprensión del funcionamiento del organismo durante el ejercicio

The aim of this personal work is to present the educational experience in the teaching of human physiology in the discipline of Physical and Sports Activity (INEF) in Madrid. An attempt has been made to contribute to the training of more than 9,500 students in this difficult discipline over the last 30 academic years. Most notable of the results is such a large dropout rate (around 48%). This dropout rate, determined by the number of students not present and the rate of absenteeism (absenteeism rate = number of students not present/total number of students), has increased significantly between the first year (1986-1987) and the 13 year (1997-1998). The absenteeism rate has now tended to stabilise. A critical view of any teacher determines the need for an analysis of the rate of such considerable absenteeism. The high average (84%) of the rate of success (success rate = the number of students who passed the course / total number of students) throughout the 28 years suggests that the problem does not lie with the teacher. It is suggested that the high rate of absenteeism lies in a series of interrelated causes: 1) the preliminary training of students, 2) the difficulty of human physiology, 3) the essence of the race and 4), understanding of the reflexive form of human physiology as the basis for understanding the functioning of the body during exercise

Lipid profile response to weight loss program in overweight and obese patient is related with gender and age.

INTRODUCTION: The risk of developing cardiovascular disease (CVD) increases with age, however CVD is markedly higher in men than in no-menopausal women. There are few interventions where compare the different effects to lose weight on lipid profile between men and women. OBJECTIVE: The aim of this study was to compare the response on the lipid profile by gender after a weight loss program, and determine whether there are differences by age group. METHODS: One hundred eighty (96 women and 84 men) overweight and obese participants (BMI 25-34.9 kg/m2) aged 18-50 years were randomised into treatment groups. The intervention period was 22 weeks (in all cases 3 times/wk of training for 22 weeks and 2 weeks for pre and post evaluation). All subjects followed a hypocaloric diet (25-30% less energy intake). Energy intake, body composition) and blood lipid profile were recorded at baseline and after of treatment. RESULTS: The response of HDL varied between men and women (p = 0.001). While in women it decreased (HDL: -2.94%, p = 0.02), HDL was elevated in men (HDL: 5% p = 0.02). After intervention men achieved decrease significantly LDL values a 6.65% more than women (p = 0.01). For TG concentrations there were significant differences between men and women in baseline however, only men had a significant chance in post-training measured (p = 0.001). TC showed significant differences between men and women in baseline (p = 0.013). After intervention, men and women showed a significant decreased to TC (p = 0.01). CONCLUSION: Men achieve a positive greater change on lipid profile than women. In addition, the favorable lipid profile response decreases with increasing age.

Introducción: el riesgo de desarrollar una enfermedad cardiovascular (ECV) se incrementa con la edad; sin embargo, el riesgo de ECV en edad fértil es mayor en hombres que en mujeres. Son pocas las intervenciones en las que se comparan las diferencias entre hombres y mujeres que un programa de pérdida de peso tiene sobre el perfil lipídico. Objetivo: comprobar el cambio en el perfil lipídico entre hombres y mujeres tras un programa de pérdida de peso, comparando las diferencias por género y categoría de edad. Métodos: ciento ochenta participantes (96 mujeres y 84 hombres) con sobrepeso y obesidad (IMC 25­34.9 kg/m2) con edades comprendidas entre los 18-50 años fueron repartidos de forma aleatoria en los diferentes grupos de intervención. El período de intervención fue de 22 semanas y 2 semanas para la evaluación pre y post. Todos los sujetos siguieron una dieta equilibrada hipocalórica (25- 30% de restricción calórica) y un programa de ejercicio 3 veces/semana. Antes y después de la intervención todos los grupos fueron evaluados de los cambios en el perfil lipídico, la composición corporal y la ingesta diaria. Resultados: hubo diferencias significativas en el cambio de HDL entre hombres y mujeres (p = 0,001). Mientras que en las mujeres disminuyó (HDL: -2,94%, p = 0,02), en los hombres hubo un aumento de la concentración de HDL (HDL: 5% p = 0,02). Después de la intervención los hombres lograron disminuir significativamente el LDL un 6,65% más que las mujeres (p = 0,01). Para concentraciones de TG hubo diferencias significativas entre hombres y mujeres al inicio de la intervención; sin embargo, solo los hombres tuvieron una mejoría significativa tras la intervención (p = 0,001). El TC mostró diferencias significativas entre hombres y mujeres preintervención (p = 0,013). Tras la intervención, los hombres y las mujeres mostraron una significativa disminución de TC (p = 0,01). Conclusión: los hombres obtuvieron un cambio más favorable en las variables del perfil lipídico con respecto a la mujeres. Además, la respuesta al perfil lipídico favorable disminuye con el aumento de la edad.