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1.
Int. j. morphol ; 41(5): 1310-1316, oct. 2023. tab
Artículo en Inglés | LILACS | ID: biblio-1521015

RESUMEN

SUMMARY: Although COVID-19 is primarily considered a respiratory pathology, it has been observed to impact other bodily systems, including the nervous system. While several studies have investigated anatomical changes in brain structures, such as volume or thickness post-COVID-19, there are no comprehensive reviews of these changes using imaging techniques for a holistic understanding. The aim of this study was to systematically analyze the literature on brain changes observed through neuroimaging after COVID-19. We conducted a systematic review according to PRISMA guidelines using Web of Science, Scopus, Medline, Pubmed, Sciencedirect, and LitCOVID. We selected studies that included adult patients during or after COVID-19 development, a control group or pre-infection images, and morphometric measurements using neuroimaging. We used the MSQ scale to extract information on sample characteristics, measured anatomical structures, imaging technique, main results, and methodological quality for each study. Out of 1126 identified articles, we included 19 in the review, encompassing 1155 cases and 1284 controls. The results of these studies indicated a lower volume of the olfactory bulb and variable increases or decreases in cortical and limbic structures' volumes and thicknesses. Studies suggest that brain changes occur post-COVID-19, primarily characterized by a smaller olfactory bulb. Additionally, there may be variations in cortical and limbic volumes and thicknesses due to inflammation or neuroplasticity, but these findings are not definitive. These differences may be attributed to methodological, geographical, and temporal variations between studies. Thus, additional studies are required to provide a more comprehensive and quantitative view of the evidence.


Aunque el COVID-19 se considera principalmente una patología respiratoria, se ha observado que afecta otros sistemas corporales, incluido el sistema nervioso. Si bien varios estudios han investigado los cambios anatómicos en las estructuras cerebrales, como el volumen o el grosor posteriores a la COVID-19, no hay revisiones exhaustivas de estos cambios que utilicen técnicas de imágenes para una comprensión holística. El objetivo de este estudio fue analizar sistemáticamente la literature sobre los cambios cerebrales observados a través de neuroimagen después de COVID-19. Realizamos una revisión sistemática de acuerdo con las pautas PRISMA utilizando Web of Science, Scopus, Medline, Pubmed, Sciencedirect y LitCOVID. Seleccionamos estudios que incluyeron pacientes adultos durante o después del desarrollo de COVID-19, un grupo de control o imágenes previas a la infección y mediciones morfométricas mediante neuroimagen. Utilizamos la escala MSQ para extraer información sobre las características de la muestra, las estructuras anatómicas medidas, la técnica de imagen, los principales resultados y la calidad metodológica de cada estudio. De 1126 artículos identificados, incluimos 19 en la revisión, que abarca 1155 casos y 1284 controles. Los resultados de estos estudios indicaron un menor volumen del bulbo olfatorio y aumentos o disminuciones variables en los volúmenes y espesores de las estructuras corticales y límbicas. Los estudios sugieren que los cambios cerebrales ocurren después del COVID-19, caracterizados principalmente por un bulbo olfatorio más pequeño. Además, pueden haber variaciones en los volúmenes y grosores corticales y límbicos debido a la inflamación o la neuroplasticidad, pero estos hallazgos no son definitivos. Estas diferencias pueden atribuirse a variaciones metodológicas, geográficas y temporales entre estudios. Por lo tanto, se requieren estudios adicionales para proporcionar una visión más completa y cuantitativa de la evidencia.


Asunto(s)
Humanos , Encéfalo/patología , Encéfalo/diagnóstico por imagen , COVID-19/complicaciones , Neuroimagen , Manifestaciones Neurológicas
2.
BMC Pulm Med ; 23(1): 333, 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37684557

RESUMEN

BACKGROUND: High drive and high effort during spontaneous breathing can generate patient self-inflicted lung injury (P-SILI) due to uncontrolled high transpulmonary and transvascular pressures, with deterioration of respiratory failure. P-SILI has been demonstrated in experimental studies and supported in recent computational models. Different treatment strategies have been proposed according to the phenotype of elastance of the respiratory system (Ers) for patients with COVID-19. This study aimed to investigate the effect of three spontaneous ventilation modes on respiratory drive and muscle effort in clinical practice and their relationship with different phenotypes. This was achieved by obtaining the following respiratory signals: airway pressure (Paw), flow (V´) and volume (V) and calculating muscle pressure (Pmus). METHODS: A physiologic observational study of a series of cases in a university medical-surgical ICU involving 11 mechanically ventilated patients with COVID-19 pneumonia at the initiation of spontaneous breathing was conducted. Three spontaneous ventilation modes were evaluated in each of the patients: pressure support ventilation (PSV), airway pressure release ventilation (APRV), and BiLevel positive airway pressure ventilation (BIPAP). Pmus was calculated through the equation of motion. For this purpose, we acquired the signals of Paw, V´ and V directly from the data transmission protocol of the ventilator (Dräger). The main physiological measurements were calculation of the respiratory drive (P0.1), muscle effort through the ΔPmus, pressure‒time product (PTP/min) and work of breathing of the patient in joules multiplied by respiratory frequency (WOBp, J/min). RESULTS: Ten mechanically ventilated patients with COVID-19 pneumonia at the initiation of spontaneous breathing were evaluated. Our results showed similar high drive and muscle effort in each of the spontaneous ventilatory modes tested, without significant differences between them: median (IQR): P0.1 6.28 (4.92-7.44) cm H2O, ∆Pmus 13.48 (11.09-17.81) cm H2O, PTP 166.29 (124.02-253.33) cm H2O*sec/min, and WOBp 12.76 (7.46-18.04) J/min. High drive and effort were found in patients even with low Ers. There was a significant relationship between respiratory drive and WOBp and Ers, though the coefficient of variation widely varied. CONCLUSIONS: In our study, none of the spontaneous ventilatory methods tested succeeded in reducing high respiratory drive or muscle effort, regardless of the Ers, with subsequent risk of P-SILI.


Asunto(s)
COVID-19 , Insuficiencia Respiratoria , Humanos , Presión de las Vías Aéreas Positiva Contínua , Músculos , Respiración , Insuficiencia Respiratoria/etiología , Insuficiencia Respiratoria/terapia , Frecuencia Respiratoria
3.
Front Psychol ; 14: 1217661, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37484087

RESUMEN

Introduction: A wide variety of instruments are used when assessing the methodological quality (MQ) of intervention programs. Nevertheless, studies on their metric quality are often not available. In order to address this shortcoming, the methodological quality scale (MQS) is presented as a simple and useful tool with adequate reliability, validity evidence, and metric properties. Methods: Two coders independently applied the MQS to a set of primary studies. The number of MQ facets was determined in parallel analyses before performing factor analyses. For each facet of validity obtained, mean and standard deviation are presented jointly with reliability and average discrimination. Additionally, the validity facet scores are interpreted based on Shadish, Cook, and Campbell's validity model. Results and discussion: An empirical validation of the three facets of the MQ (external, internal, and construct validity) and the interpretation of the scores were obtained based on a theoretical framework. Unlike other existing scales, MQS is easy to apply and presents adequate metric properties. In addition, MQ profiles can be obtained in different areas of intervention using different methodologies and proves useful for both researchers doing meta-analysis and for evaluators and professionals designing a new intervention.

4.
J Fungi (Basel) ; 9(4)2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-37108897

RESUMEN

Fungi have traditionally been considered opportunistic pathogens in primary infections caused by virulent bacteria, protozoan, or viruses. Consequently, antimycotic chemotherapy is clearly less developed in comparison to its bacterial counterpart. Currently, the three main families of antifungals (polyenes, echinocandins, and azoles) are not sufficient to control the enormous increase in life-threatening fungal infections recorded in recent decades. Natural substances harvested from plants have traditionally been utilized as a successful alternative. After a wide screening of natural agents, we have recently obtained promising results with distinct formulations of carnosic acid and propolis on the prevalent fungal pathogens Candida albicans and Cryptococcus neoformans. Here, we extended their use to the treatment against the emerging pathogenic yeast Candida glabrata, which displayed lower susceptibility in comparison to the fungi mentioned above. Taking into account the moderate antifungal activity of both natural agents, the antifungal value of these combinations has been improved through the obtention of the hydroethanolic fractions of propolis. In addition, we have demonstrated the potential clinical application of new therapeutical designs based on sequential pre-treatments with carnosic/propolis mixtures, followed by exposure to amphotericin B. This approach increased the toxic effect induced by this polyene.

6.
Front Psychol ; 13: 946273, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35992438

RESUMEN

Background: Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent psychiatric disorders among school-age children and is characterized by varying degrees of inattention, hyperactivity, and impulsivity. Diagnosis, which currently relies on the DSM-V criteria, is complex. This research proposes an integrated procedure for ADHD diagnosis in children, improving the diagnostic process and scientific research on etiopathology. Materials and methods: We conducted a clinical report on ADHD diagnosis in children (n = 92) between the ages of 8 and 13, based on the results of the application of different scales to parents of school-age children in Chile. The children were divided into two groups, those with an ADHD diagnosis (n = 44) and those without (n = 48) (24% females). Results: The results revealed statistically significant differences between groups for scales EDAH y SDQ-Cas, Conners Comprehensive Behavior Scale, Conners Parent Scale and the criteria according to the DSM-V and its dimensions, with the exception of inattention. Conclusion: The findings indicate the importance of appropriate criteria and procedures to establish a diagnosis and implement effective interventions in ADHD.

8.
Work ; 72(3): 909-920, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35634818

RESUMEN

BACKGROUND: Companies have tried to carry out interventions in order to mitigate the risks associated with losses in productivity and the health of employees. OBJECTIVE: This intervention trial evaluated the effect of a supervised exercise intervention based on aerobic capacity and strength on well-being at work and capability in performing work tasks. METHODOLOGY: The sample was composed of 67 participants (N = 67, mean age 34.31 years) and investigated a 12-week group physical exercise program in the workplace, two days per week for 50 minutes, which was supervised and based on aerobic endurance and strength. The 67 subjects were working-age office workers, deemed sedentary and randomized into an intervention (N = 40) or control (N = 27) group. Among them, 33 were men (N = 33; 49.25%) and 34 were women (N = 34, 50.75%). Outcomes were assessed pre- and post-test in both groups. The Mann-Whitney U and Chi-Square tests were performed to compare the characteristics of the intervention and control group. η2 = z/(n-1) was calculated as effect size rates. RESULTS: The program showed statistically significant effects on strength endurance (P = 0.020, η2 = 0.08), the loss of fat percentage (P = 0.015, η2 = 0.09), lower limb power (P = 0.020, η2 = 0.08) and QoL (P = 0.0001, η2 = 0.39 for the physical health outcome, and P = 0.0001, η2 = 0.35 for the outcome of total scores of mental health). CONCLUSIONS: The intervention had an impact on the endurance, fat percentage loss and QoL of the workers whose occupations were based on sedentary tasks.


Asunto(s)
Promoción de la Salud , Lugar de Trabajo , Adulto , Ejercicio Físico/psicología , Terapia por Ejercicio , Femenino , Humanos , Masculino , Proyectos Piloto , Calidad de Vida
9.
Work ; 72(3): 921-931, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35634828

RESUMEN

BACKGROUND: Sedentary tasks contribute to the deterioration of health and the appearance of chronic diseases. Physical exercise can contribute to the development of health, although the characteristics of the most appropriate program are unknown. OBJECTIVES: This is the second paper of the PRODET® intervention trial evaluating the effect of a supervised group exercise intervention in the worksite based on aerobic capacity and strength lasting 12 weeks. METHODS: The sample was composed of 67 subjects (N = 67, mean age 34.31 years) and the study investigated a 12-week group physical exercise program in the workplace, two days per week with 50-minute sessions, which was supervised and based on aerobic endurance and strength. The 67 subjects were working-age office workers, deemed as sedentary and randomized into an intervention (N = 40) or control (N = 27) group. Outcomes work ability, depression, anxiety and job satisfaction were assessed with questionnaires pre-and post-test in both groups. RESULTS: The program showed effects on the mental factor of work ability (Z = 2.36, P = 0.019, η2 = 0.09). However, there were no significant differences in the rest of the results. CONCLUSIONS: The intervention had an impact on the mental factor of work ability in the workers whose occupations were based on sedentary tasks, and reinforcing this variable with an exercise program in the workplace could contribute to reducing the mental factor of work ability.


Asunto(s)
Satisfacción en el Trabajo , Lugar de Trabajo , Adulto , Ansiedad , Depresión , Ejercicio Físico , Promoción de la Salud/métodos , Humanos , Evaluación de Capacidad de Trabajo
10.
Antibiotics (Basel) ; 10(11)2021 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-34827333

RESUMEN

Current antifungal chemotherapy against the prevalent basidiomycete Cryptococcus neoformans displays some drawbacks. This pathogenic fungus is refractory to echinocandins, whereas conventional treatment with amphotericin B plus 5-fluorocytosine has a limited efficacy. In this study, we explored the potential cryptococcal activity of some natural agents. After conducting a screening test with a set of propolis from different geographical areas, we selected an extract from China, which displayed a certain cytotoxic activity against C. neoformans, due to this extract being cheap and easily available in large amounts. The combination of this kind of propolis with carnosic acid in a 1:4 ratio induced a stronger fungicidal effect, which occurred following a synergistic pattern, without visible alterations in external cell morphology. Furthermore, several carnosic acid-propolis formulations applied onto preformed biofilms decreased the metabolic activity of the sessile cells forming biofilms. These data support the potential application of mixtures containing these two natural extracts in the design of new antifungal strategies in order to combat opportunistic infections caused by prevalent pathogenic fungi.

11.
Nutrients ; 13(7)2021 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-34371861

RESUMEN

Randomized clinical trials (RCTs) evaluating the effectiveness of interventions to promote fruit and vegetable (FV) consumption usually report intention-to-treat (ITT) analysis as the main outcome. These analyses compare the randomly assigned groups and accept that some individuals may not follow the recommendations received in their group. The ITT analysis is useful to quantify the global effect of promoting the consumption of FV in a population (effectiveness) but, if non-adherence is significant in the RCT, they cannot estimate the specific effect in the individuals that increased their FV consumption (efficacy). To calculate the efficacy of FV consumption, a per protocol analysis (PP) would have to be carried out, in which groups of individuals are compared according to their actual adherence to FV consumption, regardless of the group to which they were assigned; unfortunately, many RCTs do not report the PP analysis. The objective of this article is to apply a new method to estimate the efficacy of Meta-analysis (MA) PP which include RCTs of effectiveness by ITT, without estimates of adherence. The method is based on generating Monte Carlo simulations of percentages of adherence in each allocation group from prior distributions informed by expert knowledge. We illustrate the method reanalyzing a Cochrane Systematic Review (SR) of RCTs on increased FV consumption reported with ITT, simulating 1000 times the estimation of a PP meta-analyses, and obtaining means and ranges of the potential PP effects. In some cases, the range of estimated PP effects was clearly more favourable than the effect calculated with the original ITT assumption, and therefore this corrected analysis must be considered when estimating the true effect of the consumption of a certain food.


Asunto(s)
Encuestas sobre Dietas/estadística & datos numéricos , Metaanálisis como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación , Cumplimiento y Adherencia al Tratamiento/estadística & datos numéricos , Simulación por Computador , Frutas , Humanos , Análisis de Intención de Tratar , Método de Montecarlo , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Verduras
12.
Artículo en Inglés | MEDLINE | ID: mdl-34208668

RESUMEN

This study is based on a 40-item work climate scale in hospital emergency services (WCSHES). Teams working in these emergency services experience a heavy workload and have a limited amount of time with each patient. COVID-19 has further complicated these existing issues. Therefore, we believed it would be helpful to draft an abridged version of the 40-item WCSHES, considering both validity and reliability criteria, but giving greater weight to validity. One hundred and twenty-six workers between the ages of 20 to 64 (M = 32.45; standard deviation (SD = 9.73)) years old participated voluntarily in the study. The validity, reliability, and fit model were evaluated in an iterative process. The confirmatory factor analysis yielded appropriate global fit indices in the abridged 24-item version (Χ2(248) = 367.84; p < 0.01, RMSEA = 0.06 with an interval of 90% from 0.05 to 0.07, SRMR = 0.08, GFI = 0.9, AGFI = 0.96, CFI = 0.98, NFI = 0.95, and NNFI = 0.98), along with test criteria validity (ρXY = 0.68, p < 0.001) and excellent reliability (α = 0.94 and ω = 0.94), maintaining the same conceptualization and usefulness of the original scale. The abridged 24-item version was used to measure four work climate factors (work satisfaction, productivity/achievement of aims, interpersonal relations, and performance at work). Evidence of the usefulness of the new abridged scale is provided along with a description of our study limitations and future areas for development.


Asunto(s)
COVID-19 , Cultura Organizacional , Adulto , Humanos , Persona de Mediana Edad , Psicometría , Reproducibilidad de los Resultados , SARS-CoV-2 , Encuestas y Cuestionarios , Adulto Joven
13.
Prev Med ; 153: 106719, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34256066

RESUMEN

Restrictions during the COVID-19 pandemic are likely to decrease physical activity (PA) levels. The purpose of the study was to explore the associations between age, gender, and exercise facilities-type membership and physical activity levels during COVID-19 lockdown among users of exercise facilities from Spain. Participants were recruited among the members of 84 exercise facilities across Spain. Data was collected through an online questionnaire between 5th and 20th of April 2020 during the COVID-19 lockdown. A total of 7062 participants met inclusion criteria and responded correctly to the International Physical Activity Questionnaire. Lower levels of total PA were found in women compared with men (ß = -26, 95%CI: -40 to -13), and among older adults (ß = -48, 95%CI: -10 to -85) compared with younger ones. Moreover, users of private facilities showed higher levels of PA (ß = 40, 95%CI: 13 to 66) than those from low-cost and public facilities (reference). Lastly, women from private facilities showed greater levels of PA (ß = 63, 95%CI: 29 to 96) than low cost and public's users, an increase higher than what was found in men (ß = 7, 95%CI: -38 to 52). Therefore, gender, age and the type of exercise facility's subscription had a relevant influence on PA levels during COVID-19 lockdown in an active population. These findings are useful for public health recommendations, in order to identify subpopulations of previously active people at risk of being physically inactive during and after this pandemic.


Asunto(s)
COVID-19 , Pandemias , Anciano , Control de Enfermedades Transmisibles , Ejercicio Físico , Femenino , Humanos , Masculino , SARS-CoV-2
14.
J Aging Phys Act ; 29(2): 242-249, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33027766

RESUMEN

The study aimed to ascertain the levels of older European people's physical activity according to sociodemographic variables. The sample size was 7,893 citizens aged 65 and over from the European Union. The participants were classified as physically inactive, adequately active, or highly active, according to the World Health Organization. The total metabolic equivalents of task minutes per week were also calculated. In the results, 55.5% of older people were adequately active, and 43.8% were highly active, especially in the North and West. The average metabolic equivalents of task minutes per week was 1,313 metabolic equivalents of task minutes, with walking as the main activity, followed by moderate physical activity and vigorous activity. Male older people of a lower age from the North and West, with a higher level of education and less difficulty in paying bills, were more likely to be physically active. As a conclusion, only slightly more than half the population were adequately active. These sociodemographic inequalities show the necessity of implementing specific measures.


Asunto(s)
Ejercicio Físico , Conducta Sedentaria , Anciano , Escolaridad , Unión Europea , Humanos , Masculino , Caminata
15.
Front Psychol ; 11: 563506, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33192835

RESUMEN

There are several programs that aim to strengthen the bond between families and schools that have shown a positive impact on this relationship as well as its effectiveness in improving academic and socioemotional child indicators. Most of the studies in this area come from Anglo-Saxon countries while in Latin America research is still scarce. Thus, this study aims to assess the influence of implementing an Ecological, Participatory, Integral and Contextualized Family-School Collaboration Model (EPIC) on family involvement, social-emotional development, and cognitive test outcomes in children in elementary school. Three possible hypotheses have been considered: (1) The EPIC Family-School Collaboration Model will have a positive and significant influence on the level of family involvement; (2) The EPIC Family-School Collaboration Model will have a positive and significant influence on the results of some cognitive tests; and; (3) The EPIC Family-School Collaboration Model will have a positive and significant influence on child social-emotional development. The study included 171 students who attended second and third elementary grades in schools in Chile during 2017 and fourth and fifth grades during 2019. The children were between 7 and 12 years old (M = 8.17, SD = 0.98), during 2017 and between 9 and 14 years old (M = 9.88, SD = 0.99), during 2019. The results show that the EPIC Family-School Collaboration Model has a positive and significant influence on the level of home-based involvement, memory and attention and intrapersonal skills in the first cycle of elementary education.

16.
Microorganisms ; 8(5)2020 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-32429493

RESUMEN

The potential fungicidal action of the natural extracts, carnosic acid (obtained from rosemary) and propolis (from honeybees' panels) against the highly prevalent yeast Candida albicans, used herein as an archetype of pathogenic fungi, was tested. The separate addition of carnosic acid and propolis on exponential cultures of the standard SC5314 C. albicans strain caused a moderate degree of cell death at relatively high concentrations. However, the combination of both extracts, especially in a 1:4 ratio, induced a potent synergistic pattern, leading to a drastic reduction in cell survival even at much lower concentrations. The result of a mathematical analysis by isobologram was consistent with synergistic action of the combined extracts rather than a merely additive effect. In turn, the capacity of SC5314 cells to form in vitro biofilms was also impaired by the simultaneous presence of both agents, supporting the potential application of carnosic acid and propolis mixtures in the prevention and treatment of clinical infections as an alternative to antibiotics and other antifungal agents endowed with reduced toxic side effects.

17.
Int J Equity Health ; 15(1): 161, 2016 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-27681081

RESUMEN

BACKGROUND: Worldwide, Cervical Cancer (CC) is the fourth most common type of cancer and cause of death in women. It is a significant public health problem, especially in low and middle-income/Gross Domestic Product (GDP) countries. In the past decade, several studies of CC have been published, that identify the main modifiable and non-modifiable CC risk factors for Mexican women. However, there are no studies that attempt to explain the residual spatial variation in CC incidence In Mexico, i.e. spatial variation that cannot be ascribed to known, spatially varying risk factors. METHODS: This paper uses a spatial statistical methodology that takes into account spatial variation in socio-economic factors and accessibility to health services, whilst allowing for residual, unexplained spatial variation in risk. To describe residual spatial variations in CC risk, we used generalised linear mixed models (GLMM) with both spatially structured and unstructured random effects, using a Bayesian approach to inference. RESULTS: The highest risk is concentrated in the southeast, where the Matlapa and Aquismón municipalities register excessive risk, with posterior probabilities greater than 0.8. The lack of coverage of Cervical Cancer-Screening Programme (CCSP) (RR 1.17, 95 % CI 1.12-1.22), Marginalisation Index (RR 1.05, 95 % CI 1.03-1.08), and lack of accessibility to health services (RR 1.01, 95 % CI 1.00-1.03) were significant covariates. CONCLUSIONS: There are substantial differences between municipalities, with high-risk areas mainly in low-resource areas lacking accessibility to health services for CC. Our results clearly indicate the presence of spatial patterns, and the relevance of the spatial analysis for public health intervention. Ignoring the spatial variability means to continue a public policy that does not tackle deficiencies in its national CCSP and to keep disadvantaging and disempowering Mexican women in regard to their health care.

18.
ISA Trans ; 63: 401-412, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27056745

RESUMEN

A butterfly valve is a type of valve typically used for isolating or regulating flow where the closing mechanism takes the form of a disc. For a long time, the attention of many researchers has focused on carrying out structural (FEM) and computational fluid dynamics (CFD) analysis in order to increase the performance of this type of flow-control device. This paper proposes a novel multi-objective approach for the design optimization of a butterfly valve using advanced genetic algorithms based on Pareto dominance. Firstly, after defining the need for this study and analyzing previous papers on the subject, the initial butterfly valve is presented and the initial fluid and structural analysis are carried out. Secondly, the optimization problem is defined and the optimization strategy is presented. The design variables are identified and a parameterization model of the valve is made. Thirdly, initial design candidates are generated by DOE and design optimization using genetic algorithms is performed. In this part of the process structural and CFD analysis are calculated for each candidate simultaneously. The optimization process involves various types of software and Python scripts are needed for their interaction and the connection of all steps. Finally, a set of optimal solutions is obtained and the optimum design that provides a 65.4% stress reduction, a 5% mass reduction and a 11.3% flow increase is selected in accordance with manufacturer preferences. Validation of the results is provided by comparing experimental test results with the values obtained for the initial design. The results demonstrate the capability and potential of the proposed methodology.

19.
BMC Psychiatry ; 13: 83, 2013 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-23497463

RESUMEN

BACKGROUND: Systematic screening for depression in high-risk patients is recommended but remains controversial. The aim of this study was to assess the effectiveness of such screening in everyday clinical practice on depression recognition. METHODS: A pragmatic, cluster randomized, controlled study that randomized primary care physicians (PCPs) in Spain either to an intervention or control group. The intervention group (35-PCPs) received training in depression screening and used depression screening routinely for at least 6 months. The control group (34-PCPs) managed depression in their usual manner. Adherence to (1-6; never-very frequently), feasibility (1-4; unfeasible-very feasible), and acceptance (1-5; very poor-very good) of the screening were evaluated. Underrecognition (primary outcome) and undertreatment rates of major depressive disorder (MDD) in the two groups were compared 6 months after randomization in a random sample of 3737 patients assigned to these PCPs using logistic regression adjusting for the clustering effect. RESULTS: No significant differences were found for recognition rates (58.0% vs. 48.1% intervention vs. control; OR [95%CI] 1.40 [0.73-2.68], p = 0.309). The undertreatment rate did not differ significantly either (p = 0.390). The mean adherence to depression screening was 4.4 ± 1.0 ('occasionally'), the mean feasibility was 3.1 ± 0.5 ('moderately feasible'), and the mean acceptance was 4.2 ± 0.6 ('good'). CONCLUSIONS: This research was not able to show effectiveness of the systematic screening for MDD in high-risk patients on depression recognition in primary care. The poor adherence to screening implementation could partially explain the results. These reflect the difficulties of putting into practice the clinical guidelines usually based on interventional research. TRIAL REGISTRATION: Clinicaltrials.gov NCT01662817.


Asunto(s)
Trastorno Depresivo Mayor/diagnóstico , Tamizaje Masivo/métodos , Atención Primaria de Salud/métodos , Errores Diagnósticos/estadística & datos numéricos , Femenino , Adhesión a Directriz/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Factores de Riesgo
20.
IEEE Trans Pattern Anal Mach Intell ; 32(3): 569-75, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20075479

RESUMEN

In the machine learning field, the performance of a classifier is usually measured in terms of prediction error. In most real-world problems, the error cannot be exactly calculated and it must be estimated. Therefore, it is important to choose an appropriate estimator of the error. This paper analyzes the statistical properties, bias and variance, of the kappa-fold cross-validation classification error estimator (kappa-cv). Our main contribution is a novel theoretical decomposition of the variance of the kappa-cv considering its sources of variance: sensitivity to changes in the training set and sensitivity to changes in the folds. The paper also compares the bias and variance of the estimator for different values of kappa. The experimental study has been performed in artificial domains because they allow the exact computation of the implied quantities and we can rigorously specify the conditions of experimentation. The experimentation has been performed for two classifiers (naive Bayes and nearest neighbor), different numbers of folds, sample sizes, and training sets coming from assorted probability distributions. We conclude by including some practical recommendation on the use of kappa-fold cross validation.

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