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2.
Aesthet Surg J ; 44(8): 859-868, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38366902

RESUMEN

BACKGROUND: Liposuction is considered one of the most common procedures in plastic surgery. However, major postoperative complications such as visceral injury, fluid overload, and necrotizing fasciitis still occur. Likewise, minor complications such as ecchymosis, seromas, infections, and contour irregularities that do not threaten the life of the patient do generate significant dissatisfaction. Current evidence regarding the management of fibrosis after previous liposuction remains limited. OBJECTIVES: The objective of this article is to standardize a management algorithm based on the extensive experience and successful results of the primary author (G.M.). METHODS: Patients who underwent secondary liposculpture between August 2022 and May 2023 were evaluated prospectively. Inclusion criteria comprised females between 18 and 60 years old, nonsmokers, with a BMI < 35 kg/m2 and a history of previous body contouring surgeries. Identification of the patient's skin condition and subcutaneous lesions in the adipose tissue were obtained in detail. Statistical analysis of preoperative and postoperative medical photographs was also performed with the Fiji Biological image analyzer. RESULTS: Photographic analysis of preoperative and postoperative photographs showed a statistically significant difference between the areas affected by fibrosis (P < .001). The most frequent clinical findings were depressions in 99% of the females (74), followed by soft nodules in 95% (70), hard nodules in 81% (61), adhesions in 47% (35), and finally cutaneous bursas in 4%. CONCLUSIONS: Our classification system and management algorithm for fibrosis and contour irregularities is a safe and reliable tool. Results were objectively verified, yielding statistically significant outcomes.


Asunto(s)
Algoritmos , Fibrosis , Lipectomía , Complicaciones Posoperatorias , Humanos , Femenino , Adulto , Persona de Mediana Edad , Lipectomía/métodos , Lipectomía/efectos adversos , Adulto Joven , Estudios Prospectivos , Adolescente , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/diagnóstico , Contorneado Corporal/métodos , Contorneado Corporal/efectos adversos , Fotograbar , Resultado del Tratamiento
3.
EMBO Rep ; 24(10): e56380, 2023 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-37548091

RESUMEN

Oxidative phosphorylation and glycolysis are the dominant ATP-generating pathways in mammalian metabolism. The balance between these two pathways is often shifted to execute cell-specific functions in response to stimuli that promote activation, proliferation, or differentiation. However, measurement of these metabolic switches has remained mostly qualitative, making it difficult to discriminate between healthy, physiological changes in energy transduction or compensatory responses due to metabolic dysfunction. We therefore present a broadly applicable method to calculate ATP production rates from oxidative phosphorylation and glycolysis using Seahorse XF Analyzer data and empirical conversion factors. We quantify the bioenergetic changes observed during macrophage polarization as well as cancer cell adaptation to in vitro culture conditions. Additionally, we detect substantive changes in ATP utilization upon neuronal depolarization and T cell receptor activation that are not evident from steady-state ATP measurements. This method generates a single readout that allows the direct comparison of ATP produced from oxidative phosphorylation and glycolysis in live cells. Additionally, the manuscript provides a framework for tailoring the calculations to specific cell systems or experimental conditions.


Asunto(s)
Smegmamorpha , Animales , Smegmamorpha/metabolismo , Mitocondrias/metabolismo , Metabolismo Energético , Glucólisis , Fosforilación Oxidativa , Adenosina Trifosfato/metabolismo , Mamíferos/metabolismo
6.
Energy Effic ; 16(4): 21, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36941971

RESUMEN

Schools are complex physical and social institutions within national education systems. They account for significant energy consumption and like other buildings can demonstrate inefficient patterns of energy use. Poor energy performance of educational facilities is an intricate issue driven by complex causality of interconnected and dynamic factors. Addressing this issue requires a systemic approach, which is heretofore lacking. The aim of this research is to present and describe a systemic framework to facilitate energy reduction in schools across different European contexts. This transdisciplinary approach to sustainable energy use has been piloted in 13 post-primary schools located in six countries in northwest Europe. The research implements a series of planned activities and interventions, which help to unveil a systemic approach to improving energy efficiency in schools. The findings demonstrate how this approach, together with its ensuing methodologies and strategies, can contribute to reducing carbon emissions and improve knowledge and awareness around sustainable energy.

7.
Rev Assoc Med Bras (1992) ; 68(9): 1172-1177, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36228248

RESUMEN

OBJECTIVE: This study aimed to characterize hand hygiene behavioural intention by hospital services clusters in a medium-sized hospital in an Ecuadorian city. METHODS: This is a cross-sectional study based on the World Health Organization Hand Hygiene Knowledge Questionnaire for Health-Care Workers. The responses on hand hygiene behavioural intention for the Five Moments for hand hygiene according to the World Health Organization were recorded in three categories: before patient contact, before and after sterile technique and management of body fluids, and after contact with the environment of the patient. The variables were the knowledge regarding the source of germs causing nosocomial infections, the optimal time to achieve disinfection with alcohol, hospital services clusters (clinical medicine, surgery, and therapeutic services), and history of previous formal hand hygiene training. The variables in each moment were analysed using a saturated log-linear model. RESULTS: The average age of participants was 34 years (Q1 32.1-Q3 36.4). Of them, 62% belonged to the clinic cluster and 87.6% had previous formal hand hygiene training. The incorrect response rates for before and after sterile technique and management of body fluids, before patient contact, and after contact with the environment of the patient were 30.2, 88.4, and 99.2%, respectively. In before patient contact, the incorrect responses for optimal time depended on the department (worse surgery cluster situation), and in before and after sterile technique and management of body fluids and after contact with the environment of the patient, the incorrect responses for source of germs depended on the previous formal hand hygiene training and the department (worse surgery and clinic clusters). CONCLUSION: The incorrect answer related to hand hygiene behavioural intention was high compared to other reports, and the worse situation was found in after contact with the environment of the patient and before patient contact. These data suggest the need of strengthening permanently the hand hygiene programme.


Asunto(s)
Infección Hospitalaria , Higiene de las Manos , Adulto , Estudios Transversales , Ecuador , Adhesión a Directriz , Desinfección de las Manos/métodos , Personal de Salud/educación , Hospitales , Humanos , Intención
8.
Rev. chil. enferm. respir ; 38(3): 184-193, sept. 2022. tab
Artículo en Español | LILACS | ID: biblio-1423700

RESUMEN

Introducción: La pandemia por COVID-19 obligó a los gobiernos a implementar medidas de restricción social para proteger la salud de la población, afectando la calidad de vida de las personas, especialmente en grupos vulnerables como los niños, niñas y adolescentes (NNA). El objetivo de esta revisión sistemática (RS) fue evaluar el efecto de las medidas de restricción sobre la actividad física (AF) y conducta sedentaria (CS) de los NNA. Adicionalmente, se exploraron posibles factores determinantes de estos cambios. Métodos: Se realizó una RS, utilizando tres bases de datos. Se incluyeron estudios observacionales en donde se hubiera analizado la AF y CS de los participantes, utilizando cualquier método de evaluación. Dos investigadores analizaron los estudios, extrajeron los datos y evaluaron la calidad metodológica de los artículos primarios. El metaanálisis se realizó utilizando el modelo de efectos aleatorios, considerando un valor p < 0,05 como estadísticamente significativo. Resultados: Se incluyeron 19 artículos, con una muestra total de 15.095 NNA. La mayoría de los estudios reveló una reducción de la AF y un incremento de la CS en los sujetos, durante los confinamientos por COVID-19. El metaanálisis mostró una caída en la AF total, la AF moderada a vigorosa y un incremento del tiempo de sedentarismo. Diversos factores biodemográficos, familiares y ambientales exacerbaron las variaciones en la AF y la CS de los NNA. Conclusión: Las medidas de restricción aplicadas durante pandemia por COVID-19 redujo la AF e incrementó la CS de los NNA. Factores biodemográficos, familiares y ambientales determinaron estas variaciones.


Introduction: The COVID-19 pandemic forced governments to implement social restriction measures to protect the health of the population, affecting the quality of life of people, especially in vulnerable groups, such as children and adolescents (CA). The objective of this systematic review (SR) was to evaluate the effect of restriction measures on physical activity (PA) and sedentary behavior (SB) of CA. Additionally, possible determining factors of these changes were explored. Methods: An SR was carried out, using three databases. Observational studies were included in which the PA and SB of the participants were analyzed, using any evaluation method. Two investigators analyzed the studies, extracted data, and assessed the methodological quality of the primary articles. The meta-analysis was performed using the random effects model, considering a value of p < 0.05 as statistically significant. Results: 19 articles were included, with a total sample of 15,095 subjects. Most studies revealed a reduction in PA and an increase in SB in subjects during COVID-19 lockdowns. The meta-analysis showed a drop in total PA, moderate to vigorous PA, and an increase in sedentary time. Various biodemographic, family and environmental factors exacerbated the variations in the PA and SB of the CA. Conclusion: The restriction measures applied during the COVID-19 pandemic reduced the PA and increased the SB of the CA. Biodemographic, family and environmental factors determined these variations.


Asunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Ejercicio Físico , Conducta Sedentaria , COVID-19 , Calidad de Vida , Cuarentena , Aptitud Física , Pandemias
9.
Rev. Assoc. Med. Bras. (1992, Impr.) ; 68(9): 1172-1177, Sept. 2022. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1406645

RESUMEN

SUMMARY OBJECTIVE: This study aimed to characterize hand hygiene behavioural intention by hospital services clusters in a medium-sized hospital in an Ecuadorian city. METHODS: This is a cross-sectional study based on the World Health Organization Hand Hygiene Knowledge Questionnaire for Health-Care Workers. The responses on hand hygiene behavioural intention for the Five Moments for hand hygiene according to the World Health Organization were recorded in three categories: before patient contact, before and after sterile technique and management of body fluids, and after contact with the environment of the patient. The variables were the knowledge regarding the source of germs causing nosocomial infections, the optimal time to achieve disinfection with alcohol, hospital services clusters (clinical medicine, surgery, and therapeutic services), and history of previous formal hand hygiene training. The variables in each moment were analysed using a saturated log-linear model. RESULTS: The average age of participants was 34 years (Q1 32.1-Q3 36.4). Of them, 62% belonged to the clinic cluster and 87.6% had previous formal hand hygiene training. The incorrect response rates for before and after sterile technique and management of body fluids, before patient contact, and after contact with the environment of the patient were 30.2, 88.4, and 99.2%, respectively. In before patient contact, the incorrect responses for optimal time depended on the department (worse surgery cluster situation), and in before and after sterile technique and management of body fluids and after contact with the environment of the patient, the incorrect responses for source of germs depended on the previous formal hand hygiene training and the department (worse surgery and clinic clusters). CONCLUSION: The incorrect answer related to hand hygiene behavioural intention was high compared to other reports, and the worse situation was found in after contact with the environment of the patient and before patient contact. These data suggest the need of strengthening permanently the hand hygiene programme.

10.
BMJ Open ; 12(6): e056295, 2022 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-35710244

RESUMEN

INTRODUCTION: Asthma is a growing health problem in children in marginalised urban settings in low-income and middle-income countries. Asthma attacks are an important cause of emergency care attendance and long-term morbidity. We designed a prospective study, the Asthma Attacks study, to identify factors associated with recurrence of asthma attacks (or exacerbations) among children and adolescents attending emergency care in three Ecuadorian cities. METHODS AND ANALYSIS: Prospective cohort study designed to identify risk factors associated with recurrence of asthma attacks in 450 children and adolescents aged 5-17 years attending emergency care in public hospitals in three Ecuadorian cities (Quito, Cuenca and Portoviejo). The primary outcome will be rate of asthma attack recurrence during up to 12 months of follow-up. Data are being collected at baseline and during follow-up by questionnaire: sociodemographic data, asthma history and management (baseline only); recurrence of asthma symptoms and attacks (monthly); economic costs of asthma to family; Asthma Control Test; Pediatric Asthma Quality of life Questionnaire; and Newcastle Asthma Knowledge Questionnaire (baseline only). In addition, the following are being measured at baseline and during follow-up: lung function and reversibility by spirometry before and after salbutamol; fractional exhaled nitric oxide (FeNO); and presence of IgG antibodies to SARS-CoV-2 in blood. Recruitment started in 2019 but because of severe disruption to emergency services caused by the COVID-19 pandemic, eligibility criteria were modified to include asthmatic children with uncontrolled symptoms and registered with collaborating hospitals. Data will be analysed using logistic regression and survival analyses. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Hospital General Docente de Calderon (CEISH-HGDC 2019-001) and Ecuadorian Ministry of Public Health (MSP-CGDES-2021-0041-O N° 096-2021). The study results will be disseminated through presentations at conferences and to key stakeholder groups including policy-makers, postgraduate theses, peer-review publications and a study website. Participants gave informed consent to participate in the study before taking part.


Asunto(s)
Asma , COVID-19 , Adolescente , Asma/diagnóstico , Asma/epidemiología , Asma/terapia , COVID-19/epidemiología , Niño , Ciudades/epidemiología , Ecuador/epidemiología , Humanos , Pandemias , Estudios Prospectivos , Calidad de Vida , SARS-CoV-2
11.
BMC Health Serv Res ; 22(1): 671, 2022 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-35585557

RESUMEN

BACKGROUND: Knowledge of medical specialists' numbers and geographical distribution are essential for planning health services and health workforce supply. However, although the distribution of physicians is a significant concern for society and policymakers in Ecuador, no studies have evaluated the distribution of specialists in the country. This study aimed to explore the geographical and temporal distribution of medical specialists in Ecuador over 18 years from 2000 to 2017 and analyse its implications for health planning and medical training. METHODS: We conducted an ecological time-series study based on the National Statistical Register of Resources and Health Activities data. This register provides administrative information for health professionals working in public and private health institutions. Rates of medical specialists by year, geographical area, and speciality were estimated. We used joint-point analyses to identify time trends for medical specialists and physicians in training. RESULTS: From 2000 to 2017, medical specialists grew from 2737 to 10,929. The rate of medical specialists per 10,000 population increased from 4 in 2000 to 10.3 in 2017. Based on Joint point analysis, two temporal trends were identified. Between 2000 to 2015, specialists increased by 4.1% per year, and between 2015 and 2017, they increased by 20% per year. For the entire study period, three cities (Quito, Guayaquil, and Cuenca) accounted for more than 50% of the specialists in the country. However, medical specialists in other cities and rural areas increased from 37% in 2000 to 46% in 2017. The provinces of Esmeraldas, Carchi, Bolívar and Los Ríos presented rates of less than 6 specialists per 10,000 population by 2017. Of the 46 medical specialities identified by 2017, three represented more than 30% of the professionals (gynaecology 12%, paediatrics 11% and family and community health 8.4%). CONCLUSIONS: This study shows that the number of medical specialists in Ecuador has increased significantly over the last two decades, although with inequalities in the distribution of specialists between provinces and regions. The results of this study provide background for the Ecuadorian health system when introducing Human Resources of Health (HRH) policies.


Asunto(s)
Medicina , Médicos , Niño , Ecuador/epidemiología , Fuerza Laboral en Salud , Humanos , Especialización
12.
Arch Cardiol Mex ; 92(2): 242-252, 2022 04 04.
Artículo en Español | MEDLINE | ID: mdl-34855744

RESUMEN

Heart rate variability (HRV) corresponds to variations in heart rate or beat-beat time interval. This parameter reflects the status of the autonomic mechanisms of cardiovascular control, which may be influenced by changes characteristic of the life cycle of people, sedentary lifestyle, and various disease processes that directly or indirectly generate changes in the HRV and shift the autonomic balance, either towards greater sympathetic or parasympathetic influence on the heart. These antecedents support the use of HRV indices for the diagnosis and monitoring of various nosological entities in adults. However, there has been limited progress in the study of temporal variations in heart rhythm in the pediatric population. This article aims to describe the physiological and technical aspects of HRV in the pediatric population to provide a background that allows optimizing the application of these parameters in this age group.


La variabilidad del ritmo cardíaco (VRC) corresponde a las variaciones temporales de la frecuencia cardíaca o del intervalo latido-latido. Este parámetro refleja el estado de los mecanismos autonómicos de control cardiovascular. Los cambios propios del ciclo vital de las personas, el sedentarismo y diversos procesos de enfermedad han mostrado inducir cambios en la VRC y desplazar el balance autonómico hacia una mayor influencia simpática o parasimpática sobre el corazón. Estos antecedentes apoyan el uso de los índices de VRC para el diagnóstico y seguimiento de diversas entidades nosológicas en el adulto. Sin embargo, en la población pediátrica ha existido un limitado avance en el estudio de las variaciones temporales del ritmo cardíaco. Este artículo tiene por objetivo describir los aspectos fisiológicos y técnicos de la VRC en población pediátrica. El propósito es aportar antecedentes que permitan optimizar la aplicación de estos parámetros en este grupo etario.


Asunto(s)
Sistema Nervioso Autónomo , Corazón , Adulto , Niño , Frecuencia Cardíaca/fisiología , Humanos
13.
F1000Res ; 11: 1392, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-38434000

RESUMEN

Introduction: There are limited longitudinal data on the systemic and mucosal antibody responses to SARS-CoV-2 from Latin America, a region severely affected by COVID-19, and where vaccine strategies have been implemented during the evolving pandemic. Objective: To evaluate determinants of seroprevalence and changes in levels of anti-SARS-CoV-2 antibodies longitudinally in adults with different levels of exposure to SARS-CoV-2 (defined a priori as low, medium, and high based on presumed occupational risk), in two Andean cities in Ecuador. Methods: Longitudinal cohort study of 1,000 adults aged 18 years and older with questionnaire data and sample collection done at 0, 3, 6, and 12 months during the period 2020-2023. Observations collected included WHO-ISARIC questionnaire and peripheral blood and saliva samples for measurement of IgG and IgA antibodies, respectively. Planned analyses are tailored to the longitudinal nature of the outcomes defined by participants' antibody levels and aim at estimating their average trends with time since infection in each of the occupational groups, adjusted for demographics and calendar-time levels of SARS-CoV-2 infection in the general population. The latter reflect the impact of the national control measures such as vaccinations and movement restrictions. Importance: Understanding the duration and the dynamics of waning immunity to SARS-CoV-2, in the context of exposures to emerging virus variants and immunization, will inform the implementation of targeted public health strategies in the Latin American region. Ethics and Dissemination: This study will observe the bioethical principles of the Declaration of Helsinki. Informed written consent will be obtained. Samples from participants will be stored for up to three years after which they will be destroyed. The study protocol was approved by the Ecuadorian Ministry of Public Health Ethics Committee for COVID-19 Research. Antibody results will be provided to participants and participating institutions and to the national health authorities.


Asunto(s)
COVID-19 , SARS-CoV-2 , Adulto , Humanos , COVID-19/epidemiología , Ecuador/epidemiología , Formación de Anticuerpos , Estudios Longitudinales , Estudios Seroepidemiológicos , Anticuerpos Antivirales
14.
BMJ Open ; 11(11): e052971, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34725080

RESUMEN

INTRODUCTION: Asthma is a common long-term disorder and strategies to improve asthma control are still a challenge. Integrated delivery of health systems is critical for effective asthma care: there is limited information on experiences of care coordination for asthma from Latin America, especially on perspectives of health personnel and in the context of the COVID-19 pandemic. METHODS AND ANALYSIS: This protocol details a qualitative approach to analyse health workers' perspectives of healthcare coordination for asthma control during COVID-19 pandemic in Ecuador and Brazil, at primary and specialised levels, through in-depth semistructured interviews using a video communications platform. The analysis will identify knowledge and perspectives based on coordination of clinical information, clinical management and administrative coordination. Theoretical sampling will be used to obtain approximately equal numbers of women and men within each level of healthcare; data saturation will be used to determine sample size. Transcripts will be analysed using content-coding procedures to mark quotations related to major topics and subthemes included in the interview guide, and narrative analysis will be based on a theoretical framework for healthcare coordination to identify new themes and subthemes. ETHICS AND DISSEMINATION: Ethical approval was obtained from the ethics committees of Hospital General Docente Calderón, Quito, Ecuador; and Universidade Federal da Bahia, Salvador, Brazil. The findings of this study will be disseminated through peer-reviewed articles, conference presentations and condensed summaries for key stakeholders and partners.


Asunto(s)
Asma , COVID-19 , Asma/epidemiología , Asma/terapia , Brasil/epidemiología , Atención a la Salud , Ecuador/epidemiología , Femenino , Personal de Salud , Humanos , Masculino , Pandemias , Investigación Cualitativa , SARS-CoV-2
16.
Nat Biomed Eng ; 5(10): 1115-1130, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34155355

RESUMEN

Silicone is widely used in chronic implants and is generally perceived to be safe. However, textured breast implants have been associated with immune-related complications, including malignancies. Here, by examining for up to one year the foreign body response and capsular fibrosis triggered by miniaturized or full-scale clinically approved breast implants with different surface topography (average roughness, 0-90 µm) placed in the mammary fat pads of mice or rabbits, respectively, we show that surface topography mediates immune responses to the implants. We also show that the surface surrounding human breast implants collected during revision surgeries also differentially alters the individual's immune responses to the implant. Moreover, miniaturized implants with an average roughness of 4 µm can largely suppress the foreign body response and fibrosis (but not in T-cell-deficient mice), and that tissue surrounding these implants displayed higher levels of immunosuppressive FOXP3+ regulatory T cells. Our findings suggest that, amongst the topographies investigated, implants with an average roughness of 4 µm provoke the least amount of inflammation and foreign body response.


Asunto(s)
Implantación de Mama , Implantes de Mama , Cuerpos Extraños , Animales , Implantación de Mama/efectos adversos , Implantes de Mama/efectos adversos , Reacción a Cuerpo Extraño/etiología , Humanos , Ratones , Conejos , Siliconas/efectos adversos
17.
Nat Commun ; 12(1): 2804, 2021 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-33990571

RESUMEN

Chemotherapy remains the standard of care for most cancers worldwide, however development of chemoresistance due to the presence of the drug-effluxing ATP binding cassette (ABC) transporters remains a significant problem. The development of safe and effective means to overcome chemoresistance is critical for achieving durable remissions in many cancer patients. We have investigated the energetic demands of ABC transporters in the context of the metabolic adaptations of chemoresistant cancer cells. Here we show that ABC transporters use mitochondrial-derived ATP as a source of energy to efflux drugs out of cancer cells. We further demonstrate that the loss of methylation-controlled J protein (MCJ) (also named DnaJC15), an endogenous negative regulator of mitochondrial respiration, in chemoresistant cancer cells boosts their ability to produce ATP from mitochondria and fuel ABC transporters. We have developed MCJ mimetics that can attenuate mitochondrial respiration and safely overcome chemoresistance in vitro and in vivo. Administration of MCJ mimetics in combination with standard chemotherapeutic drugs could therefore become an alternative strategy for treatment of multiple cancers.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Adenosina Trifosfato/metabolismo , Resistencia a Antineoplásicos/fisiología , Mitocondrias/metabolismo , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular Tumoral , Respiración de la Célula/efectos de los fármacos , Respiración de la Célula/fisiología , Doxorrubicina/farmacocinética , Doxorrubicina/farmacología , Resistencia a Múltiples Medicamentos/fisiología , Femenino , Proteínas del Choque Térmico HSP40/deficiencia , Proteínas del Choque Térmico HSP40/metabolismo , Humanos , Técnicas In Vitro , Ratones , Ratones Endogámicos NOD , Ratones SCID , Mitocondrias/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Consumo de Oxígeno/efectos de los fármacos
18.
Sensors (Basel) ; 21(4)2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33572272

RESUMEN

The number of connected IoT devices is significantly increasing and it is expected to reach more than two dozens of billions of IoT connections in the coming years. Low Power Wide Area Networks (LPWAN) have become very relevant for this new paradigm due to features such as large coverage and low power consumption. One of the most appealing technologies among these networks is LoRaWAN. Although it may be considered as one of the most mature LPWAN platforms, there are still open gaps such as its capacity limitations. For this reason, this work proposes a collision avoidance resource allocation algorithm named the Collision Avoidance Resource Allocation (CARA) algorithm with the objective of significantly increase system capacity. CARA leverages the multichannel structure and the orthogonality of spreading factors in LoRaWAN networks to avoid collisions among devices. Simulation results show that, assuming ideal radio link conditions, our proposal outperforms in 95.2% the capacity of a standard LoRaWAN network and increases the capacity by almost 40% assuming a realistic propagation model. In addition, it has been verified that CARA devices can coexist with LoRaWAN traditional devices, thus allowing the simultaneous transmissions of both types of devices. Moreover, a proof-of-concept has been implemented using commercial equipment in order to check the feasibility and the correct operation of our solution.

20.
BMJ Open ; 10(10): e040735, 2020 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-33067302

RESUMEN

OBJECTIVES: There are few population-based estimates for prevalence of past exposure to dengue and chikungunya viruses despite common epidemiological features. Here, we have developed a novel statistical method to study patterns of age-dependent prevalence of immunity in a population following exposures to two viruses which share similar epidemiological features including mode of transmission and induction of long-lasting immunity. This statistical technique accounted for sociodemographic characteristics associated with individuals and households. SETTINGS: The data consist of a representative sample from an ongoing longitudinal birth cohort set-up in a tropical district in coastal Ecuador (Esmeraldas). PARTICIPANTS: We collected data and blood samples from 319 individuals belonging to 152 households following epidemics of the infections in 2015 in Latin America. PRIMARY OUTCOME: Plasma was tested for the presence of specific IgG antibodies to dengue and chikungunya viruses by commercial ELISA and defined a bivariate binary outcome indicating individuals' past exposure status to dengue and chikungunya (ie, presence/absence of IgG antibodies to dengue or chikungunya or both). RESULTS: Dengue seroprevalence increased rapidly with age reaching 97% (95% credible interval (CrI): 93%-99%) by 60 years. Chikungunya seroprevalence peaked at 42% (95% CrI: 18%-66%) around 9 years of age and averaged 27% (95% CrI: 8.7%-51.6%) for all ages. Rural areas were more likely to be associated with dengue-only exposure while urban areas and shorter distance to the nearest household were associated with exposures to both. Women living in urban settings were more likely to be chikungunya seropositive while rural men were more likely to be dengue seropositive. CONCLUSION: Dengue seroprevalence was strongly age dependent consistent with endemic exposure while that of chikungunya peaked in childhood consistent with the recent emergence of the virus in the study area. Our findings will inform control strategies for the two arboviruses in Ecuador including recommendations by the WHO on dengue vaccination.


Asunto(s)
Fiebre Chikungunya , Virus del Dengue , Dengue , Anticuerpos Antivirales , Fiebre Chikungunya/epidemiología , Estudios Transversales , Dengue/epidemiología , Ecuador/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos
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