Development of Continuous Assessment of Muscle Quality and Frailty in Older Patients Using Multiparametric Combinations of Ultrasound and Blood Biomarkers: Protocol for the ECOFRAIL Study.

BACKGROUND: Frailty resulting from the loss of muscle quality can potentially be delayed through early detection and physical exercise interventions. There is a demand for cost-effective tools for the objective evaluation of muscle quality, in both cross-sectional and longitudinal assessments. Literature suggests that quantitative analysis of ultrasound data captures morphometric, compositional, and microstructural muscle properties, while biological assays derived from blood samples are associated with functional information. OBJECTIVE: This study aims to assess multiparametric combinations of ultrasound and blood-based biomarkers to offer a cross-sectional evaluation of the patient frailty phenotype and to track changes in muscle quality associated with supervised exercise programs. METHODS: This prospective observational multicenter study will include patients aged 70 years and older who are capable of providing informed consent. We aim to recruit 100 patients from hospital environments and 100 from primary care facilities. Each patient will undergo at least two examinations (baseline and follow-up), totaling a minimum of 400 examinations. In hospital environments, 50 patients will be measured before/after a 16-week individualized and supervised exercise program, while another 50 patients will be followed up after the same period without intervention. Primary care patients will undergo a 1-year follow-up evaluation. The primary objective is to compare cross-sectional evaluations of physical performance, functional capacity, body composition, and derived scales of sarcopenia and frailty with biomarker combinations obtained from muscle ultrasound and blood-based assays. We will analyze ultrasound raw data obtained with a point-of-care device, along with a set of biomarkers previously associated with frailty, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Additionally, we will examine the sensitivity of these biomarkers to detect short-term muscle quality changes and functional improvement after a supervised exercise intervention compared with usual care. RESULTS: At the time of manuscript submission, the enrollment of volunteers is ongoing. Recruitment started on March 1, 2022, and ends on June 30, 2024. CONCLUSIONS: The outlined study protocol will integrate portable technologies, using quantitative muscle ultrasound and blood biomarkers, to facilitate an objective cross-sectional assessment of muscle quality in both hospital and primary care settings. The primary objective is to generate data that can be used to explore associations between biomarker combinations and the cross-sectional clinical assessment of frailty and sarcopenia. Additionally, the study aims to investigate musculoskeletal changes following multicomponent physical exercise programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT05294757; https://clinicaltrials.gov/ct2/show/NCT05294757. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/50325.

Energy Deposition around Swift Carbon-Ion Tracks in Liquid Water.

Energetic carbon ions are promising projectiles used for cancer radiotherapy. A thorough knowledge of how the energy of these ions is deposited in biological media (mainly composed of liquid water) is required. This can be attained by means of detailed computer simulations, both macroscopically (relevant for appropriately delivering the dose) and at the nanoscale (important for determining the inflicted radiobiological damage). The energy lost per unit path length (i.e., the so-called stopping power) of carbon ions is here theoretically calculated within the dielectric formalism from the excitation spectrum of liquid water obtained from two complementary approaches (one relying on an optical-data model and the other exclusively on ab initio calculations). In addition, the energy carried at the nanometre scale by the generated secondary electrons around the ion's path is simulated by means of a detailed Monte Carlo code. For this purpose, we use the ion and electron cross sections calculated by means of state-of-the art approaches suited to take into account the condensed-phase nature of the liquid water target. As a result of these simulations, the radial dose around the ion's path is obtained, as well as the distributions of clustered events in nanometric volumes similar to the dimensions of DNA convolutions, contributing to the biological damage for carbon ions in a wide energy range, covering from the plateau to the maximum of the Bragg peak.

Electronic excitation spectra of cerium oxides: from ab initio dielectric response functions to Monte Carlo electron transport simulations.

Nanomaterials made of cerium oxides CeO2 and Ce2O3 have a broad range of applications, from catalysts in automotive, industrial or energy operations to promising materials to enhance hadrontherapy effectiveness in oncological treatments. To elucidate the physico-chemical mechanisms involved in these processes, it is of paramount importance to know the electronic excitation spectra of these oxides, which are obtained here through high-accuracy linear-response time-dependent density functional theory calculations. In particular, the macroscopic dielectric response functions  of both bulk CeO2 and Ce2O3 are derived, which compare remarkably well with the available experimental data. These results stress the importance of appropriately accounting for local field effects to model the dielectric function of metal oxides. Furthermore, we reckon the energy loss functions Im(-1/) of the materials, including the accurate evaluation of the momentum transfer dispersion from first-principles calculations. In this respect, by using Mermin-type parametrization we are able to model the contribution of different electronic excitations to the dielectric loss function. Finally, from the knowledge of the electron inelastic mean free path, together with the elastic mean free path provided by the relativistic Mott theory, we carry out statistical Monte Carlo (MC) electron transport simulations to reproduce the major features of the reported experimental reflection electron energy loss (REEL) spectra of cerium oxides. The good agreement with REEL experimental data strongly supports our approach based on MC modelling, whose main inputs were obtained using ab initio calculated electronic excitation spectra in a broad range of momentum and energy transfers.

Determinantes sociales de salud y su relación con desnutrición infantil en dos comunidades étnicas colombianas / Social determinants and malnutrition of infants from two Colombian indigenous communities

RESUMEN Objetivo Identificar la relación entre los determinantes sociales de la salud y el estado nutricional de los niños pertenecientes a dos comunidades indígenas de la Costa Caribe colombiana, los wayús y los zenús. Métodos Estudio transversal que aborda el estado nutricional de los wayús y los zenús en edad preescolar y escolar. Incluyendo, además, estimación de determinantes sociales de la salud, referida por cuidadores de menores, que aborda algunos aspectos de ejes de desigualdad de tipo estructural (etnia, territorio, edad y sexo) e intermedios: vivienda, entorno y redes, mediante instrumentos de salud familiar. Se estandarizaron métricas de talla, peso e insumos de familiograma y ecomapa. Se estimaron medidas descriptivas de tipo frecuentistas y de medidas de tendencia central. Se estimó la odds ratio y su relación con variables independientes. Resultados La prevalencia de desnutrición global en la etnia Wayú fue del 59,1% IC (47,569,8) y en la etnia Zenú del 22,4% IC (15,9-30,4) para una p<0,001. Esta diferencia se relaciona con factores de riesgo intermediarios de saneamiento: inadecuadas excretas con OR=2.54; IC (1.42-4.53) p=0.002, la falta de empleo OR=1.94; IC (1.09-3.46) P=0.03 y falta de acceso a servicios de salud occidental OR=2.42; IC (1.34-4.40) p=0.005. Conclusiones La mejora en la nutrición requiere intervenir determinantes intermedios relacionados con saneamiento, modelo de salud, intersectorialidad de políticas en salud más enfoque étnico-cultural y territorial.

ABSTRACT Objetive To identify the relationship between the Health's Social Determinants and the nutritional status of children belonging to two indigenous communities on the Colombian Caribbean coast, the Wayú and the Zenú. Methods Cross-sectional study that addresses nutritional status in wayúes and zenúes at preschool and school age. Also including the estimation of health's social determinants, referred by minor's caregivers, which addresses some aspects of structural ¡nequality axes (ethnicity, territory, age, and sex) and intermediates: housing, environment, and networks, through health instruments family. Metrics for height, weight, and inputs for the familiogram and ecomap were standardized. Descriptive measures of frequencies and central tendency were estimated. Odds ratio and its relationship with ¡ndependent variables were estimated. Results The prevalence of global malnutrition in the Wayú ethnic group was 59.1% (47.5-69.8) and in the Zenú ethnic group 22.4% (15.9-30.4) for a p<0.001. This difference is related to intermedíate risk factors with sanitation: inadequate excreta with OR=2.54; CI (1.42-4.53) p=0.002, lack of employment OR=1.94; CI (1.09-3.46) P=0.03 and lack of access to western health services OR=2.42; IC (1.34-4.40) p=0.005. Conclusions Improvement in nutrition requires the intervention of intermediate determinants related to sanitation, health model, intersectoriality of health policies plus an ethnic-cultural and territorial focus.

COVID-19 outbreak in long-term care facilities from Spain. Many lessons to learn.

BACKGROUND/OBJECTIVES: To analyze mortality, costs, residents and personnel characteristics, in six long-term care facilities (LTCF) during the outbreak of COVID-19 in Spain. DESIGN: Epidemiological study. SETTING: Six open LTCFs in Albacete (Spain). PARTICIPANTS: 198 residents and 190 workers from LTCF A were included, between 2020 March 6 and April 5. Epidemiological data were also collected from six LTCFs of Albacete for the same period of time, including 1,084 residents. MEASUREMENTS: Baseline demographic, clinical, functional, cognitive and nutritional variables were collected. 1-month and 3-month mortality was determined, excess mortality was calculated, and costs associated with the pandemics were analyzed. RESULTS: The pooled mortality rate for the first month and first three months of the outbreak were 15.3% and 28.0%, and the pooled excess mortality for these periods were 564% and 315% respectively. In facility A, the percentage of probable COVID-19 infected residents were 33.6%. Probable infected patients were older, frail, and with a worse functional situation than those without COVID-19. The most common symptoms were fever, cough and dyspnea. 25 residents were transferred to the emergency department, 21 were hospitalized, and 54 were moved to the facility medical unit. Mortality was higher upon male older residents, with worse functionality, and higher comorbidity. During the first month of the outbreak, 65 (24.6%) workers leaved, mainly with COVID-19 symptoms, and 69 new workers were contracted. The mean number of days of leave was 19.2. Costs associated with the COVID-19 in facility A were estimated at € 276,281/month, mostly caused by resident hospitalizations, leaves of workers, staff replacement, and interventions of healthcare professionals. CONCLUSION: The COVID-19 pandemic posed residents at high mortality risk, mainly in those older, frail and with worse functional status. Personal and economic costs were high.

Comparative Assessment of Two Strategies for Interpreting Tumor Markers in Ascitic Effusions.

BACKGROUND/AIM: There are two strategies for the interpretation of tumor markers (TM) in fluid effusions: i) high cut-off and ii) fluid/serum ratio (F/S) and low cut-off. The objective of this study is to compare these two strategies and to determine whether diagnostic accuracy improves by the identification of possible false positives using Adenosine deaminase (ADA), C reactive protein (CRP) and % of polymorphonuclear cells (%PN). PATIENTS AND METHODS: We studied 157 ascitic fluids, 74 of which were malignant. ADA, CRP and %PN were determined in ascitic fluid, and Carcinoembryonic antigen (CEA), Cancer antigen 72-4 (CA72-4), Cancer antigen CA19-9 and Cancer antigen 15-3 (CA15-3) in both fluid and serum. RESULTS: The strategy of high cut-off showed 59.5% sensitivity at 100% specificity. The F/S strategy showed 75.7% sensitivity at 95.2% specificity. Subclassifying cases with ADA, CRP and %PN negative showed 67.5% sensitivity at 100% specificity for high cut-off and for the F/S strategy was 81.7% sensitivity at 98.7% specificity. CONCLUSION: The strategy of F/S with negative ADA, CRP and %PN allow the best interpretation for TM in the ascitic fluid.

Energy Spectra of Protons and Generated Secondary Electrons around the Bragg Peak in Materials of Interest in Proton Therapy.

The number and energy of secondary electrons generated around the trajectories of swift protons interacting with biological materials are highly relevant in proton therapy, due to the prominent role of low-energy electrons in the production of biodamage. For a given material, electron energy distributions are determined by the proton energy; and it is imperative that the distribution of proton energy at depths around the Bragg peak region be described as accurately as possible. With this objective, we simulated the energy distributions of proton beams of clinically relevant energies (50-300 MeV) at depths around the Bragg peak in liquid water and the water-equivalent polymer poly(methyl methacrylate) (PMMA). By using a simple model, this simulation has been conveniently extended to account for nuclear fragmentation reactions, providing depth-dose curves in excellent agreement with available experimental data. Special care has been taken to describe the electronic excitation spectrum of the target, taking into account its condensed phase nature. A predictive formula has been obtained for the mean value and the width of the proton energy distribution at the Bragg peak depth, quantities which are found to grow linearly with the initial energy of the beam, in good agreement with available data. To accurately characterize (in number and energy) the electrons generated around the proton paths, the energy distributions of the latter at each depth have been convoluted with the energy-dependent ionization inverse mean free paths. This results in a number of low-energy electrons around the Bragg peak larger than when only the proton beam average energy at the given depths is considered. The convoluted ionization inverse mean free path closely resembles the Bragg curve shape. The average energy of the secondary electrons is nearly constant (∼55 eV for liquid water and ∼43 eV for PMMA) in the plateau of the Bragg curve, independent of the proton incident energy and suddenly decaying once the Bragg peak is reached. These findings highlight the importance of a precise calculation of the proton beam energy distribution as a function of the target depth to reliably characterize the secondary electrons generated around the Bragg peak region.

Assessment of a Combined Panel of Six Serum Tumor Markers for Lung Cancer.

RATIONALE: We have previously identified six serum tumor markers (TMs) (carcinoembryonic antigen, carbohydrate antigen 15.3, squamous cell carcinoma-associated antigen, cytokeratin-19 fragment, neuron-specific enolase, and pro-gastrin-releasing peptide) related to the presence of lung cancer (LC). OBJECTIVES: To validate their individual performance in an independent cohort, and to explore if their combined assessment (≥1 abnormal TM value) is a more accurate marker for LC presence. METHODS: We determined these six TMs in 3,144 consecutive individuals referred to our institution by their primary care physician because of the clinical suspicion of LC. MEASUREMENTS AND MAIN RESULTS: LC was excluded in 1,316 individuals and confirmed in 1,828 patients (1,563 with non-small cell LC and 265 with small cell LC). This study validated the previously reported performance of each individual TM. We also showed that their combined assessment (≥1 abnormal TM) had a better sensitivity, specificity, negative predictive value, and positive predictive value (88.5, 82, 83.7, and 87.3%, respectively) than each TM considered individually and that it increased the diagnostic performance (area under the curve) of a clinical model that included tumor size, age, and smoking status. In patients with radiographic nodules less than 3 cm, the negative predictive value of the TM panel was 71.8%, hence providing some support for a more conservative diagnostic approach. Finally we identified two TMs (neuron-specific enolase and pro-gastrin-releasing peptide) that differentiate the risk of non-small cell LC from that of small cell LC. CONCLUSIONS: The combined assessment of a panel of six serum TMs is a more accurate marker for LC presence than these same TMs considered individually. The potential of these TMs in the diagnostic and screening settings deserves further research.

Factores sociodemográficos y motivacionales asociados a la actividad física en estudiantes universitarios / Levels of physical activity among colombian university students

Background: Physical inactivity is an important risk factor for chronic diseases in Western societies. Aim: To determine the sociodemographic and motivational factors associated with physical activity in college students. Material and Methods: The International Physical Activity Questionnaire (IPAQ) -short form- and the “motives for physical activities measure-revised” (MPAM-R) questionnaire were applied to 900 university students aged 20 ± 3 years (60% women). The frequency, level and motivations for engaging in physical activity and associated demographic factors were analyzed. Results: Twenty two percent of students were classified as having a high level of physical activity, 54.8% had a low level and 13.9% were considered inactive. According to MET consumption, 68.9% of students are inactive and only 16.8% of students classified as very active. Ninety two percent of active students performed physical activity for health reasons. A significant association between gender and social motivation was observed. Conclusions: A high prevalence of physical inactivity was found in these students. Males showed higher levels of physical activity than females.

[Inequalities and sociodemographic characteristics of maternal mortality in La Guajira, Colombia, 2010-2012]. / Desigualdades y características sociodemográficas de la mortalidad materna en La Guajira, Colombia, 2010­2012.

OBJECTIVE: Identify the inequalities and sociodemographic characteristics that negatively affect maternal mortality in the department of La Guajira, Colombia. METHODS: A descriptive study was conducted in which cases of maternal deaths in the department of La Guajira between 2010 and 2012 were analyzed, based on data from secondary sources. The difference in rates, rate ratio, population attributable risk percent, and Gini and concentration coefficients were calculated. RESULTS: 54 maternal deaths were recorded, 61.1% of which were indigenous and 16.7% Afro-Colombians; the majority did not have any schooling (33.3%) or only primary schooling (29.6%). Inequalities in the difference of rates, rate ratio, and population attributable risk percent were calculated for La Guajira and other departments in the Caribbean region and in Colombia; however, the differences were not reflected in the Gini and concentration coefficients. CONCLUSIONS: Maternal mortality was significantly higher in indigenous women than in non-indigenous women. Sexual and reproductive health programs should be strengthened and maternal health policies improved through a multicultural approach to eliminate or reduce inequalities related to maternal mortality in this population.

Desigualdades y características sociodemográficas de la mortalidad materna en La Guajira, Colombia, 2010-2012 / Inequalities and sociodemographic characteristics of maternal mortality in La Guajira, Colombia, 2010-2012

OBJETIVO: Identificar las desigualdades y las características sociodemográficas que inciden negativamente en la mortalidad materna en el departamento de La Guajira, Colombia. MÉTODOS: Se realizó un estudio descriptivo, en el que se analizaron los casos de muerte materna ocurridos en el departamento de La Guajira entre 2010 y 2012, a partir de datos de fuentes secundarias. Se calculó la diferencia de las tasas, la razón de las tasas y el riesgo atribuible poblacional porcentual, además de los índices de Gini y de concentración. RESULTADOS: Se registraron 54 muertes maternas, de ellas, 61,1% eran indígenas y 16,7% afrocolombianas; la mayoría no tenía ningún estudio (33,3%) o solo estudios primarios (29,6%). Se encontraron desigualdades en la diferencia de las tasas, la razón de las tasas y el riesgo atribuible poblacional porcentual, entre La Guajira y otros departamentos de la región Caribe y del país; sin embargo, esas diferencias no se reflejaron en los índices de Gini y de concentración. CONCLUSIONES: La mortalidad materna fue significativamente más elevada en las mujeres indígenas en comparación con las no indígenas. Se deben fortalecer los programas de salud sexual y reproductiva y adelantar dentro de las políticas de salud materna un enfoque multicultural para eliminar o reducir las desigualdades relacionadas con la mortalidad materna en esta población.

OBJECTIVE: Identify the inequalities and sociodemographic characteristics that negatively affect maternal mortality in the department of La Guajira, Colombia. METHODS: A descriptive study was conducted in which cases of maternal deaths in the department of La Guajira between 2010 and 2012 were analyzed, based on data from secondary sources. The difference in rates, rate ratio, population attributable risk percent, and Gini and concentration coefficients were calculated. RESULTS: 54 maternal deaths were recorded, 61.1% of which were indigenous and 16.7% Afro-Colombians; the majority did not have any schooling (33.3%) or only primary schooling (29.6%). Inequalities in the difference of rates, rate ratio, and population attributable risk percent were calculated for La Guajira and other departments in the Caribbean region and in Colombia; however, the differences were not reflected in the Gini and concentration coefficients. CONCLUSIONS: Maternal mortality was significantly higher in indigenous women than in non-indigenous women. Sexual and reproductive health programs should be strengthened and maternal health policies improved through a multicultural approach to eliminate or reduce inequalities related to maternal mortality in this population.

Validation of new cancer biomarkers: a position statement from the European group on tumor markers.

BACKGROUND: Biomarkers are playing increasingly important roles in the detection and management of patients with cancer. Despite an enormous number of publications on cancer biomarkers, few of these biomarkers are in widespread clinical use. CONTENT: In this review, we discuss the key steps in advancing a newly discovered cancer candidate biomarker from pilot studies to clinical application. Four main steps are necessary for a biomarker to reach the clinic: analytical validation of the biomarker assay, clinical validation of the biomarker test, demonstration of clinical value from performance of the biomarker test, and regulatory approval. In addition to these 4 steps, all biomarker studies should be reported in a detailed and transparent manner, using previously published checklists and guidelines. Finally, all biomarker studies relating to demonstration of clinical value should be registered before initiation of the study. SUMMARY: Application of the methodology outlined above should result in a more efficient and effective approach to the development of cancer biomarkers as well as the reporting of cancer biomarker studies. With rigorous application, all stakeholders, and especially patients, would be expected to benefit.

[Levels of physical activity among colombian university students]. / Factores sociodemográficos y motivacionales asociados a la actividad física en estudiantes universitarios.

BACKGROUND: Physical inactivity is an important risk factor for chronic diseases in Western societies. AIM: To determine the sociodemographic and motivational factors associated with physical activity in college students. MATERIAL AND METHODS: The International Physical Activity Questionnaire (IPAQ) -short form- and the "motives for physical activities measure-revised" (MPAM-R) questionnaire were applied to 900 university students aged 20 ± 3 years (60% women). The frequency, level and motivations for engaging in physical activity and associated demographic factors were analyzed. RESULTS: Twenty two percent of students were classified as having a high level of physical activity, 54.8% had a low level and 13.9% were considered inactive. According to MET consumption, 68.9% of students are inactive and only 16.8% of students classified as very active. Ninety two percent of active students performed physical activity for health reasons. A significant association between gender and social motivation was observed. CONCLUSIONS: A high prevalence of physical inactivity was found in these students. Males showed higher levels of physical activity than females.

Social capital and its relationship to self-perceived health: national health survey in Colombia 2007.

OBJECTIVE: To analyze the self-reported perceived health related to socio-demographic characteristics, social health inequalities and social capital in Colombia. METHODS: This study is a cross-sectional design; data was obtained from the National Health Survey of Colombia 2007. INDEPENDENT VARIABLES: socio-demographic characteristics; component variables: social health inequality and social capital. Dependent variable: self-reported health. Analysis of the relationship used logistic regression through OR and its confidence interval. RESULTS: The determinant factors for a negative health perceptions are related to being a female (OR: 0.49 [0.47 to 0.52]), and in both genders being older than 37 years of age (OR: 0.72 [0.61 to 0.85]), living without a partner, black ethnicity, indigenous women (0.80 [0.69 to 0.94] and low economic incomes. DISCUSSION: The relationship between social determinants and social capital in the perception of health shows inequities and indirectly reflects the level of health. Given the policies and the model of health, requires a rational adjustment of the goals, programs, and national and regional strategies with the object of improving the demand and quality of services.

OBJETIVO: Analizar la percepción de salud relacionada con características sociodemográficas, las desigualdades sociosanitarias y el capital social en Colombia. MÉTODOS: Los datos provenientes de la Encuesta nacional de salud de Colombia 2007. Variables independientes: características sociodemográficas y variables componentes: desigualdad sociosanitaria y capital social. Variable dependiente percepción del estado de salud. Análisis de la relación mediante regresión logística a través de la OR y su intervalo de confianza. RESULTADOS: Los factores determinantes para una percepción negativa de salud están relacionados con ser mujer (OR: 0.49 [0.47-0.52]), para hombres y mujeres ser mayor de 37 años (OR: 0.72 [0.61-0.85]), vivir sin pareja, ethnicidad negro/a; indígena en mujeres (0.80 [0.69-0.94] y bajos ingresos económicos. DISCUSIÓN: La relación entre los determinantes sociales y el capital social en la percepción de salud muestra inequidades y reflejan indirectamente el nivel de salud; dadas las políticas y el modelo de salud se requiere un ajuste racional de las metas y programas y estrategias nacionales y regionales con el objeto de mejorar la demanda y la calidad de los servicios.

Social capital and relationship with self-rated health. National health survey in Colombia / Capital social y su relación con la precepción de salud. Encuensta nacional de salud, Colombia 2007

Abstract Objective: To analyze the self-reported perceived health related to socio-demographic characteristics, social health inequalities and social capital in Colombia. Methods: This study is a cross-sectional design; data was obtained from the National Health Survey of Colombia 2007. Independent variables: socio-demographic characteristics; component variables: social health inequality and social capital. Dependent variable: selfreported health. Analysis of the relationship used logistic regression through OR and its confidence interval. Results: The determinant factors for a negative health perceptions are related to being a female (OR: 0.49 [0.47 to 0.52]), and in both genders being older than 37 years of age (OR: 0.72 [0.61 to 0.85]), living without a partner, black ethnicity, indigenous women (0.80 [0.69 to 0.94] and low economic incomes. Discussion: The relationship between social determinants and social capital in the perception of health shows inequities and indirectly reflects the level of health. Given the policies and the model of health, requires a rational adjustment of the goals, programs, and national and regional strategies with the object of improving the demand and quality of services.

Resumen Objetivo: Analizar la percepción de salud relacionada con características sociodemográficas, las desigualdades sociosanitarias y el capital social en Colombia. Métodos: Los datos provenientes de la Encuesta nacional de salud de Colombia 2007. Variables independientes: características sociodemográficas y variables componentes: desigualdad sociosanitaria y capital social. Variable dependiente percepción del estado de salud. Análisis de la relación mediante regresión logística a través de la OR y su intervalo de confianza. Resultados: Los factores determinantes para una percepción negativa de salud están relacionados con ser mujer (OR: 0.49 [0.47-0.52]), para hombres y mujeres ser mayor de 37 años (OR: 0.72 [0.61-0.85]), vivir sin pareja, ethnicidad negro/a; indígena en mujeres (0.80 [0.690.94] y bajos ingresos económicos. Discusión: La relación entre los determinantes sociales y el capital social en la percepción de salud muestra inequidades y reflejan indirectamente el nivel de salud; dadas las políticas y el modelo de salud se requiere un ajuste racional de las metas y programas y estrategias nacionales y regionales con el objeto de mejorar la demanda y la calidad de los servicios.

Relación entre el grado de madurez neuropsicológica infantil y el índice de talla y peso en niños de 3 a 7 años escolarizados de estratos socioeconómicos dos y tres de la ciudad de Barranquilla (Colombia) / Relationship between neuropsychological maturity and the rate of size and weight in school children from 3 to 7 years with socio-economic stratum two and three in Barranquilla (Colombia)

Objetivo: Determinar la relación entre el grado de madurez neuropsicológica infantil y el índice de talla y peso en niños de 3 a 7 años que acuden a instituciones de educación básica primaria de carácter oficial de estratos socioeconómicos dos y tres de la ciudad de Barranquilla, entre 2009 y 2010. Materiales y métodos: Estudio descriptivo observacional. Se aplicaron 189 pruebas de Cumanin para evaluar el desarrollo neuropsicológico y se midió peso y talla estandarizada. Se realizó análisis descriptivo de los datos y tabulación en Excel exportado a SPSS versión 18 en español. Resultados: Se detectó un 8% de bajo peso para la edad con un 82.4% de la población con peso adecuado para la edad en comparación con un 5.9% de talla baja y el 83% talla adecuada para la edad. La evaluación neuropsicológica reportó un porcentaje de déficit de 19.7%, en contraste con un 22.9% con desarrollo medio adecuado para la edad. Conclusiones: No se logró demostrar la asociación entre el peso y talla con el desarrollo neuropsicológico, relacionado esto con el bajo porcentaje de niños con alteraciones del peso y la talla que se encontró en nuestra población de estudio; aunque cabe notar la detección de una clara alteración en el ritmo a medida que va avanzando la edad, siendo importante complementar estudios sobre el desarrollo neuropsicológico en nuestra población.

Objective: To determine the relation between the degree of maturity neuropsychological infantile and the index of height and weight in children from 3 to 7 years that come to a few institutions of basic primary education of an official nature of socioeconomic strata two and three of Barranquilla's city, between 2009 and 2010. Materials and methods: Observational descriptive study applied 189 Cumanin's tests to themselves to evaluate the development neuropsychological and weight and standardized height measured up. A descriptive analysis of the information was realized, its tabulation was done in Excel and then exported to SPSS version 18 in Spanish. Results: It was detected 8% of low weight for the age with 82.4 % of the population with weight adapted for the age in comparison with 5.9 % of low height and 83 % height adapted for the age, the evaluation neuropsychological bring a percentage of deficit of 19.7 % in contrast with 22.9 % with average development adapted for the age. Conclusions: It was not possible to determine the association between the weight and height with the development neuropsychological related this to the low percentage of children with alterations of the weight and the height that one found in our population of study, though it is necessary to notice the detection of a clear alteration in the pace as it is advancing the age, being it important to complement studies on the development neuropsychological in our population.

Niñez afectada con VIH/SIDA: Uso y acceso a Servicios de Salud en cinco ciudades colombianas / Children Affected with HIV/AIDS: Use and access to Health Services in five colombian cities

Objetivos: Describir patrones de uso y barreras de acceso a servicios de salud en población infantil afectada con VIH/SIDA residente en Cali, Buenaventura, Barranquilla, Santa Marta y Cartagena. Materiales y métodos: 286 encuestas personales realizadas a 11 menores que conocían su diagnóstico para VIH y 275 a cuidadores de menores que no conocían su situación de afectación para VIH. Empleándose instrumento diseñado por los autores, se realizó análisis descriptivo de datos y tabulación en SPSS, versión 15, en español. Resultados: [96,2 % (n=275)] de los cuidadores retrasan la entrega del diagnóstico por temor al estigma en caso de que el menor revele involuntariamente su diagnóstico a otras personas, y para protegerlo del posible daño psicológico que genere la noticia. Se encontró patrón de utilización frecuente del servicio de salud con tiempo de espera superior a 30 minutos [53,8 % (n=154)]. La mayoría de los menores no reciben atención domiciliaria [85,7% (n=245)]. Los cuidadores expresan que reciben atención en salud respetuosa y amable [70,6% (n=259)]; no obstante, en los testimonios de grupos focales en Buenaventura se manifiesta una- ausencia de garantía de un servicio respetuoso y que brinde la confidencialidad necesaria respecto al diagnóstico de seropositividad para VIH/SIDA. Discusión: Los servicios de salud deben superar algunos obstáculos para asegurar no solo el acceso a la atención, sino también incrementar la disponibilidad, equidad, integralidad y calidad desde la perspectiva de derechos y con objeto de beneficiar a las personas seropositivas para VIH/SIDA.

Objective: To describe patterns of use and barriers to access to health services for children affected with HIV/AIDS living in Cali, Buenaventura, Barranquilla, Santa Marta and Cartagena. Materials and methods: 286 personal surveys conducted with 11 children who knew their HIV diagnosis and, 275 caregivers of children who did not know their HIV status of involvement. Using an instrument designed by the authors, a descriptive analysis and tabulation was performed of data and tabulation in SPSS, version 15, in Spanish. Results: [96.2% (n=275)] of the caregivers reported the delivery delay of diagnosis for fear of stigma if the child discloses the diagnosis inadvertently to other people and, to protect it from possible psychological damage that generates the news. A Pattern was found of frequent use of health service whose waiting time exceeds 30 minutes [53.8% (n=154)]. Most children do not receive home care [85.7% (n=245)]. Caregivers reported receiving health care respectfully and friendly [70.6% (n=259)], however, in the testimonies of focus groups in Buenaventura shows the lack of guarantee of a respectful and, to provide the necessary confidentiality regarding the diagnosis of HIV/AIDS. Discussion: Health services must overcome some obstacles to ensuring not only access to care, but also to increase the availability, fairness, integrity and quality from the perspective of rights and in order to benefit people living with HIV/AIDS for HIV / AIDS.

A combined molecular dynamics and Monte Carlo simulation of the spatial distribution of energy deposition by proton beams in liquid water.

We have evaluated the spatial distribution of energy deposition by proton beams in liquid water using the simulation code SEICS (Simulation of Energetic Ions and Clusters through Solids), which combines molecular dynamics and Monte Carlo techniques and includes the main interaction phenomena between the projectile and the target constituents: (i) the electronic stopping force due to energy loss to target electronic excitations, including fluctuations due to the energy-loss straggling, (ii) the elastic scattering with the target nuclei, with their corresponding energy loss and (iii) the dynamical changes in projectile charge state due to electronic capture and loss processes. An important feature of SEICS is the accurate account of the excitation spectrum of liquid water, based on a consistent solid-state description of its energy-loss-function over the whole energy and momentum space. We analyse how the above-mentioned interactions affect the depth distribution of the energy delivered in liquid water by proton beams with incident energies of the order of several MeV. Our simulations show that the position of the Bragg peak is determined mainly by the stopping power, whereas its width can be attributed to the energy-loss straggling. Multiple elastic scattering processes contribute slightly only at the distal part of the Bragg peak. The charge state of the projectiles only changes when approaching the end of their trajectories, i.e. near the Bragg peak. We have also simulated the proton-beam energy distribution at several depths in the liquid water target, and found that it is determined mainly by the fluctuation in the energy loss of the projectile, evaluated through the energy-loss straggling. We conclude that a proper description of the target excitation spectrum as well as the inclusion of the energy-loss straggling is essential in the calculation of the proton beam depth-dose distribution.

Síntesis de matrriales microcompuestos de poliailina/arcilla: caracterización y evaluación de su actividad como agentes anticorrosioos / Synthesi of polyyanilineclay microcomposite materials: characterizationn and assessment of its activity as anticorrosive agetss / Síntese d materiiais micro-compostos de polianilina/argila: caracterização e avaliação da sua atividade como agentes anti-corossivos

En el presente trabajo se realiza la síntesis de materiales “microcompuestos” a partir de polianilina en su forma esmeraldina base y dos montmorillonitas colombianas. Las arcillas naturales fueron sometidas a intercambio catiónico con una sal de amonio cuaternaria para obtener arcillas organofílicas que posteriormente fueron modificadas con polianilina mediante polimerización oxidativa in situ. La caracterización de los sólidos mediante espectroscopía infrarroja (FT-IR), difracción de rayos X (DRX), SEM y DSC evidencia la síntesis exitosa de los materiales mediante intercalación o delaminación de los minerales de arcilla. Los sólidos sintetizados se evaluaron como agentes anticorrosivos mediante mediciones electroquímicas de potencial de corrosión, resistencia de polarización y corriente de corrosión sobre electrodos de acero cold-rolled 1020 (AISI-SAE). Se encontró que los microcompuestos sintetizados brindan protección a la superficie del acero contra los agentes corrosivos, obteniendo diferencias significativas entre los materiales microcompuestos de polianilina/ arcilla, sin que éstos superen el potencial anticorrosivo de la polianilina en su forma esmeraldina base pura.

In the present work microcomposites-materials from polyaniline as emeraldine- base and two Colombian montmorillonites were synthesized. The natural clays were subjected to cationic exchange with an ammonium quaternary salt in order to obtain organophilic clays to be modified with polyaniline by an “in situ” oxidative polymerization. Characterization by infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), SEM and DSC reveals the successful synthesis of materials by means of intercalation or delamination of the clay minerals. The synthesized solids were assessed as anticorrosive agents by electrochemical measurements of corrosion potential, polarization resistance and corrosion current on electrodes of cold-rolled 1020 (AISI-SAE) steel. It was found that the synthesized microcomposites provide protection to the surface of steel against corrosive agents, obtaining in this way important difference between the microcomposites materials of polyaniline/ clay, without they can surpass the anticorrosive potential of the polyaniline in the pure emeraldine-base form.

No presente trabalho realizou-se a síntese de materiais “micro-compostos” a partir de polianilina em sua forma esmeraldina base e duas montmorillonitas colombianas. As argilas naturais foram submetidas a intercâmbio catiónico com uma sal da amônia quaternaria para obter argilas organofílicas que foram modificadas posteriormente com polianilina mediante polimerização oxidativa “in situ”. A caracterização dos sólidos mediante espectroscopia de absorção na região de infravermelho (FT-IR), difração de raios X (DRX), microscopia eletrônica de varredura (SEM) e DSC evidência a síntese exitosa dos materiais mediante intercalação ou elaminação dos minerais da argila. Os sólidos sintetizados foram avaliados como agentes anti-corrosivos mediante medidas eletroquímicas do potencial da corrosão, resistência do polarização e corrente da corrosão sobre elétrodos de aço cold-rolled 1020 (AISI-SAE). Encontrou-se que os micro-compostos sintetizados oferecem proteção à superfície do aço contra os agentes corrosivos, obtendo-se diferenças importantes entre os materiais micro-compostos de polianilina/ argila, sem que estes superem o potencial anti-corrosivo da polianilina em sua forma esmeraldina base pura.