Applications of CFD for Process Safety

Nowadays, the statistical studies have revealed that major accidents (MA) are frequent in diverse industries, which has originated the development of strategies and normative focussed in foreseeing and preventing these. Thus, the process safety is in continuous improvement. The experimental studies in this field result in situations of high risks and are usually expensive. Therefore, the implementation of developments as the computational fluid dynamics (CFD) techniques is now applied, and has proven to be advantageous. In this work, CFD models for pool and jet fires are presented, as these kinds of fires are usually involved in major accidents. The results of the CFD models show orders of magnitude and behaviors in good agreement with experimental observations found in literature. The outputs of the simulations showed values of around 500 and 1400 K for the pool fires; while the jet fires predictions were of temperatures around 500 and 1050 K. Furthermore, the information obtained by these models can be used in order to develop safety plans to diminish risks in the facilities designs, safe zones and emergency exit routes

CFD Modelling of Coupled Multiphysics-Multiscale Engineering Cases

Many of the engineering problems have multiphysics and multiscale nature. Non-isothermal flows, stirred reactors, turbulent mixing and membrane filtration, are prevalent cases in which the coupling of several physics phenomena is required for the adequate prediction of overall behaviors. Also, a multiscale analysis, where the same phenomenon is analyzed at different scales, can lead to better understanding of the phenomena, which can be used in optimization and to provide adequate scale-up methodologies. Studies incorporating both multiscale and multiphysics analysis are rarely addressed in literature; in fact, these kinds of problems will be the research challenge in the next years. Computer fluid dynamics (CFD) techniques have shown to be promising to deal with these kinds of systems. In this chapter, these are used to implement a multiscale analysis of the hydrodesulphurization (HDS) process for light gas-oil (LGO). The aforementioned is carried out by the analysis of mass an energy transport at: (1) microporous (MP) scale, (2) pseudo-homogeneous catalyst (PHC) scale, and by analysis of (3) momentum and mass transport at reactor scale (RS). In addition, a particular discussion is made regarding the proper establishment of the model, its validation, the use of different boundary conditions, its justification; and the dependence of solutions of parameters and initial and boundary conditions

Antifungal prophylaxis following heart transplantation : systematic review

Q1Q1Artículo original429-436Patients with heart transplantation have a high incidence of infectious complications, especially fungal infections. The aim of the systematic review was to determine the best pharmacological strategy to prevent fungal infections among patients with heart transplant. We searched the PubMed and Embase databases for studies reporting the effectivenesss of pharmacologic strategies to prevent fungal infections in adult patient with a heart transplant. Our search yielded five studies (1176 patients), four of them with historical controls. Two studies used inhaled amphotericin B deoxycholate, three used itraconazole and one used targeted echinocandin. All studies showed significant reduction in the prophylaxis arm. Different products, doses and outcomes were noted. There is a highly probable benefit of prophylaxis use, however, better studies with standardised doses and comparators should be performed

CFD Analysis of BED Textural Characteristics on TBR Behavior: Hydrodynamics and Scaling-up

In recent years, CFD has played an important role in the understanding and design of TBR’s. In this work, through CFD with Eulerian approach, a three-phase heterogeneous reactor model was developed, were the accuracy of Interfacial Momentum Exchange Model (IMEM) for the gas-solid interaction, the effect of a more detailed catalytic bed geometry description, and the pellet shape over TBR hydrodynamics of two fluid phases interacting with the solid phase was studied. Then, a second model was developed, where the validated hy- drodynamic model was coupled with mass transport for an HDS process of light gasoil. Additionally, in order to insight into the scaling up process of a TBRs, the proposed columns behaviors were compared against lit- erature columns using four different ways, and it was found that the best predictions were obtained when the models’ holdup were equaled to those evaluated in literature columns. Since in reliable literature deviations in pressure drop predictions of around 30% can be found, the model results show significant improvement against literature, achieving 5 times better accuracy in predicting pressure drops, and 50% improvement in holdup prediction; the coupled model reproduces the same conversion values compared with literature data, and predicts conversions with 95% accurac

Análise das infecções associadas à assistência à saúde antes e durante a pandemia de COVID-19 em um hospital colombiano

Highlights Gram-negative bacilli prevail in Healthcare-Associated Infections, revealing a microbial landscape shaped by COVID-19. Bacteremia emerges as a high-risk factor, especially impacting immunosuppressed or oncologic patients in our Colombian healthcare institution. Cephalosporin and carbapenem resistance pose a significant hurdle, emphasizing the evolving trends amidst the COVID-19 Impact on Healthcare Infections. Our study underscores the transformative impact of COVID-19 on healthcare infections, spotlighting emerging patterns and challenges in a high-complexity Colombian institution. Introduction: Healthcare-associated infections pose a significant challenge, contributing to hospital morbidity and mortality. Objective: To describe the behavior of Healthcare Associated Infections before and during the pandemic reported to a high-complexity health institution in Colombia. Material and Methods: In our retrospective observational study on Healthcare-Associated Infections (HAIs), we analyzed data from all in-patients diagnosed with HAIs between 2018 and 2020. This included clinical, demographic, microbiological, and microbial susceptibility information collected from the Committee on Nosocomial Infections' prospective database. Data from 391 isolates were obtained using Whonet software for antimicrobial resistance surveillance. Results: We found 504 cases of HAIs (2018-2020) with an overall in-hospital infection rate of 2.55/1000 patient-days. The median age for pediatric patients was 5 years, and for adults, 56 years, with 57% male. The leading admission diagnoses were oncologic disease complications (31%). Bacteremia had a 30-day mortality rate of 13%, predominantly catheter-associated (37%). Gram-negative bacilli, notably  Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, represented 58% cases of HAI. Discussion: The critical need for specific interventions and antimicrobial management to control HAIs, especially given the challenges posed by the COVID-19 pandemic, is highlighted. Conclusions: This is the first report on HAIs incidence at a tertiary hospital in Bucaramanga, Santander (Colombia). Bacteremia was predominant; 75% of HAIs patients had comorbidities. Gram-negative bacilli prevailed; a notable rise in ICU respiratory infections occurred during the 2020 COVID-19 pandemic. Resistance to cephalosporins and carbapenems was prevalent. How to cite this article: Wintaco Luz M, Quintero-Lesmes Doris C, Vargas-Soler José A, Barrera Diego M, Palacio Laura N, Granados Ulises, Uribe Luis G “Analysis Healthcare Infections before and during of COVID-19 pandemic in a Colombian hospital”. Revista Cuidarte. 2024;15(1):e3624.  http://dx.doi.org/10.15649/cuidarte.3624Introducción: Las infecciones asociadas a la atención en salud (IAAS) representan un reto porque estas contribuyen a la morbilidad y mortalidad hospitalaria.  Objetivo: Describir el comportamiento de las IAAS antes y durante la pandemia, las cuales fueron reportadas a una institución de salud de alta complejidad en Colombia.  Materiales y métodos: En nuestro estudio observacional retrospectivo de las IAAS, analizamos los datos de todos los pacientes hospitalizados que fueron diagnosticados con una IAAS entre 2018 y 2020. Esto incluyó información clínica, demográfica, microbiológica y de susceptibilidad microbiana recabada de la base de datos prospectiva del Comité de Infecciones Nosocomiales. Los datos de 391 aislamientos se obtuvieron utilizando el programa informático Whonet para la vigilancia de la resistencia a los antimicrobianos. Resultados: Encontramos 504 casos de IAAS entre 2018 y 2020 con una tasa global de infección intrahospitalaria de 2,55/1000 pacientes al día. La mediana de edad de los pacientes pediátricos fue de 5 años y la de los adultos de 56 y el 57% de ellos eran varones. Los principales diagnósticos de ingreso fueron complicaciones oncológicas (31%). La bacteriemia tuvo una tasa de mortalidad a los 30 días del 13%, predominantemente asociada al uso de catéter (37%). Los bacilos gramnegativos, sobre todo Klebsiella pneumoniae, Escherichia coli y Pseudomonas aeruginosa, representaron el 58% de los casos de IAAS. Discusión: Se destaca la necesidad crítica de contar con intervenciones específicas y de gestión antimicrobiana para controlar las IAAS, especialmente teniendo en cuenta los retos que planteó la pandemia de Covid-19.  Conclusiones: Este es el primer informe sobre la incidencia de las IAAS en un hospital terciario de Bucaramanga, Santander (Colombia). La bacteriemia predominó y 75% de los pacientes con IAAS presentaban comorbilidades. Predominaron los bacilos gramnegativos y se produjo un notable aumento de las infecciones respiratorias en las UCI durante la pandemia Covid-19 de 2020. Fue prevalente la resistencia a las cefalosporinas y a los carbapenémicos. Como citar este artículo: Wintaco Luz M, Quintero-Lesmes Doris C, Vargas-Soler José A, Barrera Diego M, Palacio Laura N, Granados Ulises, Uribe Luis G “Analysis Healthcare Infections before and during of COVID-19 pandemic in a Colombian hospital”. Revista Cuidarte. 2024;15(1):e3624.  http://dx.doi.org/10.15649/cuidarte.3624Introdução: As infeções associadas aos cuidados de saúde representam um desafio significativo, contribuindo para a morbilidade e mortalidade hospitalar.   Objetivo: Descrever o comportamento das Infecções Relacionadas à Assistência à Saúde antes e durante a pandemia notificadas a uma instituição de saúde de alta complexidade na Colômbia. Material e Métodos: Em nosso estudo observacional retrospectivo sobre Infecções Relacionadas à Assistência à Saúde (IRAS), analisamos dados de todos os pacientes internados com diagnóstico de IRAS entre 2018 e 2020. Isso incluiu informações clínicas, demográficas, microbiológicas e de suscetibilidade microbiana coletadas do Comitê no banco de dados prospectivo de infecções hospitalares. Os dados de 391 isolados foram obtidos utilizando o software Whonet para vigilância da resistência antimicrobiana. Resultados:  Foram encontrados 504 casos de IRAS (2018-2020) com taxa global de infecção hospitalar de 2,55/1.000 pacientes-dia. A idade média para pacientes pediátricos foi de 5 anos, para adultos 56 anos, sendo 57% do sexo masculino. Os principais diagnósticos de admissão foram complicações  de doenças oncológicas (31%). A bacteremia teve uma taxa de mortalidade em 30 dias de 13%, predominantemente   associada ao cateter (37%). Bacilos Gram-negativos, notadamente Klebsiella pneumoniae, Escherichia coli e Pseudomonas aeruginosa, representaram 58% dos casos de IRAS. Discussão: É destacada a necessidade crítica de intervenções específicas e gestão antimicrobiana para controlar as IACS, especialmente tendo em conta os desafios colocados pela pandemia da COVID-19. Conclusões: Este é o primeiro relatório sobre a incidência de IRAS em um hospital terciário em Bucaramanga, Santander (Colômbia). A bacteremia foi predominante; 75% dos pacientes com IRAS apresentavam comorbidades. Prevaleceram bacilos Gram-negativos; um aumento notável nas infecções respiratórias em UTI ocorreu durante a pandemia de COVID-19 de 2020. A resistência à cefalosporina e aos carbapenêmicos foi prevalente. Como citar este artículo: Wintaco Luz M, Quintero-Lesmes Doris C, Vargas-Soler José A, Barrera Diego M, Palacio Laura N, Granados Ulises, Uribe Luis G “Analysis Healthcare Infections before and during of COVID-19 pandemic in a Colombian hospital”. Revista Cuidarte. 2024;15(1):e3624.  http://dx.doi.org/10.15649/cuidarte.362

Casimir energy in spherical cavities

We calculate the Casimir energy at spherical cavities within a host made up of an arbitrary material described by a possibly dispersive and lossy dielectric response. To that end, we add to the coherent optical response a contribution that takes account of the incoherent radiation emitted by the host in order to guarantee the detailed balance required to keep the system at thermodynamic equilibrium in the presence of dissipation. The resulting boundary conditions allow a conventional quantum mechanical treatment of the radiation within the cavity from which we obtain the contribution of the cavity walls to the density of states, and from it, the thermodynamic properties of the system. The contribution of the cavity to the energy diverges as it incorporates the interaction energy between neighbor atoms in a continuum description. The change in the energy of an atom situated at the center of the cavity due to its interaction with the fluctuating cavity field is however finite. We evaluate the latter for a simple case.Comment: 9 pages, 4 figures, Proceedings of QFEXT07. To be published in J. Phys.

Analysis of Healthcare-associated Infections before and during the COVID-19 pandemic in a Colombian hospital

Introduction: Healthcare-associated infections pose a significant challenge, contributing to hospital morbidity and mortality. Objective: To describe the behavior of Healthcare Associated Infections before and during the pandemic reported to a high-complexity health institution in Colombia. Material and Methods: In our retrospective observational study on Healthcare-Associated Infections (HAIs), we analyzed data from all in-patients diagnosed with HAIs between 2018 and 2020. This included clinical, demographic, microbiological, and microbial susceptibility information collected from the Committee on Nosocomial Infections' prospective database. Data from 391 isolates were obtained using Whonet software for antimicrobial resistance surveillance. Results: We found 504 cases of HAIs (2018-2020) with an overall in-hospital infection rate of 2.55/1000 patient-days. The median age for pediatric patients was 5 years, and for adults, 56 years, with 57% male. The leading admission diagnoses were oncologic disease complications (31%). Bacteremia had a 30-day mortality rate of 13%, predominantly catheter-associated (37%). Gram-negative bacilli, notably Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, represented 58% cases of HAI. Discussion: The critical need for specific interventions and antimicrobial management to control HAIs, especially given the challenges posed by the COVID-19 pandemic, is highlighted. Conclusions: This is the first report on HAIs incidence at a tertiary hospital in Bucaramanga, Santander (Colombia). Bacteremia was predominant; 75% of HAIs patients had comorbidities. Gram-negative bacilli prevailed; a notable rise in ICU respiratory infections occurred during the 2020 COVID-19 pandemic. Resistance to cephalosporins and carbapenems was prevalent

The Acute Optic Neuritis Network (ACON): Study protocol of a non-interventional prospective multicenter study on diagnosis and treatment of acute optic neuritis

Optic neuritis (ON) often occurs at the presentation of multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). The recommended treatment of high-dose corticosteroids for ON is based on a North American study population, which did not address treatment timing or antibody serostatus. The Acute Optic Neuritis Network (ACON) presents a global, prospective, observational study protocol primarily designed to investigate the effect of time to high-dose corticosteroid treatment on 6-month visual outcomes in ON. Patients presenting within 30 days of the inaugural ON will be enrolled. For the primary analysis, patients will subsequently be assigned into the MS-ON group, the aquapotin-4-IgG positive ON (AQP4-IgG+ON) group or the MOG-IgG positive ON (MOG-IgG+ON) group and then further sub-stratified according to the number of days from the onset of visual loss to high-dose corticosteroids (days-to-Rx). The primary outcome measure will be high-contrast best-corrected visual acuity (HC-BCVA) at 6 months. In addition, multimodal data will be collected in subjects with any ON (CIS-ON, MS-ON, AQP4-IgG+ON or MOG-IgG+ON, and seronegative non-MS-ON), excluding infectious and granulomatous ON. Secondary outcomes include low-contrast best-corrected visual acuity (LC-BCVA), optical coherence tomography (OCT), magnetic resonance imaging (MRI) measurements, serum and cerebrospinal fluid (CSF) biomarkers (AQP4-IgG and MOG-IgG levels, neurofilament, and glial fibrillary protein), and patient reported outcome measures (headache, visual function in daily routine, depression, and quality of life questionnaires) at presentation at 6-month and 12-month follow-up visits. Data will be collected from 28 academic hospitals from Africa, Asia, the Middle East, Europe, North America, South America, and Australia. Planned recruitment consists of 100 MS-ON, 50 AQP4-IgG+ON, and 50 MOG-IgG+ON. This prospective, multimodal data collection will assess the potential value of early high-dose corticosteroid treatment, investigate the interrelations between functional impairments and structural changes, and evaluate the diagnostic yield of laboratory biomarkers. This analysis has the ability to substantially improve treatment strategies and the accuracy of diagnostic stratification in acute demyelinating ON

The Acute Optic Neuritis Network (ACON): Study protocol of a non-interventional prospective multicenter study on diagnosis and treatment of acute optic neuritis

Optic neuritis (ON) often occurs at the presentation of multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). The recommended treatment of high-dose corticosteroids for ON is based on a North American study population, which did not address treatment timing or antibody serostatus. The Acute Optic Neuritis Network (ACON) presents a global, prospective, observational study protocol primarily designed to investigate the effect of time to high-dose corticosteroid treatment on 6-month visual outcomes in ON. Patients presenting within 30 days of the inaugural ON will be enrolled. For the primary analysis, patients will subsequently be assigned into the MS-ON group, the aquapotin-4-IgG positive ON (AQP4-IgG+ON) group or the MOG-IgG positive ON (MOG-IgG+ON) group and then further sub-stratified according to the number of days from the onset of visual loss to high-dose corticosteroids (days-to-Rx). The primary outcome measure will be high-contrast best-corrected visual acuity (HC-BCVA) at 6 months. In addition, multimodal data will be collected in subjects with any ON (CIS-ON, MS-ON, AQP4-IgG+ON or MOG-IgG+ON, and seronegative non-MS-ON), excluding infectious and granulomatous ON. Secondary outcomes include low-contrast best-corrected visual acuity (LC-BCVA), optical coherence tomography (OCT), magnetic resonance imaging (MRI) measurements, serum and cerebrospinal fluid (CSF) biomarkers (AQP4-IgG and MOG-IgG levels, neurofilament, and glial fibrillary protein), and patient reported outcome measures (headache, visual function in daily routine, depression, and quality of life questionnaires) at presentation at 6-month and 12-month follow-up visits. Data will be collected from 28 academic hospitals from Africa, Asia, the Middle East, Europe, North America, South America, and Australia. Planned recruitment consists of 100 MS-ON, 50 AQP4-IgG+ON, and 50 MOG-IgG+ON. This prospective, multimodal data collection will assess the potential value of early high-dose corticosteroid treatment, investigate the interrelations between functional impairments and structural changes, and evaluate the diagnostic yield of laboratory biomarkers. This analysis has the ability to substantially improve treatment strategies and the accuracy of diagnostic stratification in acute demyelinating ON. Trial registration: ClinicalTrials.gov, identifier: NCT05605951