Plume-scale confinement on thermal convection.

Despite the ubiquity of thermal convection in nature and artificial systems, we still lack a unified formulation that integrates the system's geometry, fluid properties, and thermal forcing to characterize the transition from free to confined convective regimes. The latter is broadly relevant to understanding how convection transports energy and drives mixing across a wide range of environments, such as planetary atmospheres/oceans and hydrothermal flows through fractures, as well as engineering heatsinks and microfluidics for the control of mass and heat fluxes. Performing laboratory experiments in Hele-Shaw geometries, we find multiple transitions that are identified as remarkable shifts in flow structures and heat transport scaling, underpinning previous numerical studies. To unveil the mechanisms of the geometrically controlled transition, we focus on the smallest structure of convection, posing the following question: How free is a thermal plume in a closed system? We address this problem by proposing the degree of confinement [Formula: see text]-the ratio of the thermal plume's thickness in an unbounded domain to the lateral extent of the system-as a universal metric encapsulating all the physical parameters. Here, we characterize four convective regimes different in flow dimensionality and time dependency and demonstrate that the transitions across the regimes are well tied with [Formula: see text]. The introduced metric [Formula: see text] offers a unified characterization of convection in closed systems from the plume's standpoint.

Lake surface cooling drives littoral-pelagic exchange of dissolved gases.

The extent of littoral influence on lake gas dynamics remains debated in the aquatic science community due to the lack of direct quantification of lateral gas transport. The prevalent assumption of diffusive horizontal transport in gas budgets fails to explain anomalies observed in pelagic gas concentrations. Here, we demonstrate through high-frequency measurements in a eutrophic lake that daily convective horizontal circulation generates littoral-pelagic advective gas fluxes one order of magnitude larger than typical horizontal fluxes used in gas budgets. These lateral fluxes are sufficient to redistribute gases at the basin-scale and generate concentration anomalies reported in other lakes. Our observations also contrast the hypothesis of pure, nocturnal littoral-to-pelagic exchange by showing that convective circulation transports gases such as oxygen and methane toward both the pelagic and littoral zones during the daytime. This study challenges the traditional pelagic-centered models of aquatic systems by showing that convective circulation represents a fundamental lateral transport mechanism to be integrated into gas budgets.

Severe viral lower respiratory tract infections in Brazilian children: Clinical features of a national cohort.

BACKGROUND: The accurate etiological diagnosis of lower respiratory tract infections (LRTI) is essential for their effective clinical management. The extensive use of molecular methods during the COVID-19 pandemic has enabled massive data acquisition on viral lower respiratory tract infections. The current study aims to identify clinical features associated with eight viral agents among children presenting severe LRTI. METHODS: retrospective cohort study of data from the Brazilian Influenza Epidemiological Surveillance Information System. Patients under 20 years-old who had severe LRTI with etiological confirmation through RT-PCR between 2020 and 2022 were included. Binary logistic regressions were used to examine associations between pathogens and symptoms. RESULTS: 60,657 cases were assessed. The main viral agents detected were Sars-CoV-2 (COV2) (41.2%), Respiratory Syncytial Virus (29.1%), Human Rhinovirus (HRV) (12.1%), and Influenza (FLU) (5.5%). A general mortality rate of 4.3% was observed. The multivariate analysis evidenced that COV2 less likely presented with cough (OR: 0.34; 95%CI: 0.32-0.36), respiratory discomfort (Adjusted Odds Ratio (aOR): 0.61; 95%Confidence Interval (CI): 0.59-0.64), and desaturation (aOR: 0.71; 95%CI: 0.69-0.75). RSV strongly associated with cough (aOR: 2.59; 95%CI: 2.45-2.75) and respiratory discomfort (aOR: 1.54; 95%CI: 1.46-1.62), whereas FLU was linked to fever (aOR: 2.27; 95%CI: 2.06-2.50) and sore throat (aOR: 1.48; 95%CI: 1.34-1.64). CONCLUSIONS: The viral agents responsible for severe LRTI have distinct associations with clinical features in children.

Revisión de pares, preprints y revistas depredadoras. Ética editorial versus publicidad aplicada a la ciencia médica / Peer review, preprints and predatory journals. Publication ethics versus publicity applied to medical science

Abstract The publication of medical articles has become increasingly complex, linked to multiple factors. It poses difficult problems for both authors and journals themselves. This Editorial addresses current and controversial issues: peer review, preprints as a new way of disseminating knowledge, the growing number of publications without peer review and its variants, and the risks of predatory publications. The article proposes future guidelines as an editorial policy of MEDICINA. The controversy continues, and surely the passage of time will place our proposal in a changing scientific world like knowledge itself.

Assessment of the risk of burnout and its associated factors in healthcare professionals during the COVID-19 pandemic: A prospective cohort study.

Introduction: The COVID-19 pandemic resulted in tremendous physical and psychological pressure on healthcare professionals, especially on those working in intensive care units (ICUs) and Emergency Departments (EDs). The present study intended to characterize the profile of these professionals which is associated with burnout and determine the potential predictors of such condition. Methods: A Prospective cohort study was carried out in a tertiary hospital between March 2020 and March 2021, in Salvador, Brazil. A standardized and validated version of the Oldenburg Burnout inventory (OLBI) was applied to assess risk of burnout together with data forms designed to collect information on sociodemographic characteristics and religious beliefs. ICU and ED healthcare professionals were evaluated during off-hours at two distinct periods of the COVID-19 pandemic, in 2020 and in 2021. Differences in the results obtained from each study participant between the timepoints were compared. A binary logistic regression analysis was performed to identify the predictors of burnout development independent of other confounding factors. Results: Seventy-seven healthcare professionals with a median age of 33 (interquartile range [IQR]: 31-37.5) years and predominantly female (72.7%; n = 56) were enrolled. There were 62 professionals at risk of developing burnout through the OLBI. Those had a median age of 33 (IQR: 31-37) and female predominance (71%, n = 44). Disengagement and burnout were the only features which frequencies significantly changed over time, with increasing detection at the latest timepoint. Alcohol consumption was found to be an important risk factor for burnout development [adjusted odds ratio (aOR): 10.8 (95% CI: 1.8-64.2)]. Importantly, working in the ICU [aOR: 0.04 (95%CI: 0.01-0.32)] and the habit of praying daily [aOR: 0.07 (95%CI: 0.01-0.41)] were characteristics linked to reduced odds of burnout. Discussion: Disengagement substantially increased during the COVID-19 pandemic in healthcare professionals. Alcohol consumption favors the onset of burnout whereas habit of praying daily and working in the ICU are protective against such outcome. Institutional policies aimed at minimizing etilism may positively impact mental health of these professionals.

[Peer review, preprints and predatory journals. Publication ethics versus publicity applied to medical science]. / Revisión de pares, preprints y revistas depredadoras. ética editorial versus publicidad aplicada a la ciencia médica.

The publication of medical articles has become increasingly complex, linked to multiple factors. It poses difficult problems for both authors and journals themselves. This Editorial addresses current and controversial issues: peer review, preprints as a new way of disseminating knowledge, the growing number of publications without peer review and its variants, and the risks of predatory publications. The article proposes future guidelines as an editorial policy of MEDICINA. The controversy continues, and surely the passage of time will place our proposal in a changing scientific world like knowledge itself.

South Atlantic explosive cyclones in 2014-2015: study employing NCEP2 and MERRA-2 reanalyses.

An analysis of explosive cyclone cases was produced by comparing the reanalysis of MERRA-2 (high spatial resolution) and NCEP2 (low spatial resolution) to South Atlantic in the 2014-2015 period. A total of 51 cases were found, of which 49 were detected by the first reanalysis and 33 by the second (2 cases identified by NCEP2 were not identified by MERRA-2). Spring was the dominant season in the formation of the cases in both reanalyses. It was observed that most systems are formed preferentially eastward of a preexisting trough at higher levels, while others are formed under an almost zonal upper airstream. This difference is more evident in the NCEP2. It was also diagnosed that the MERRA-2 shows more clearly the diffluence in the 250 hPa flow. The analysis of the composite fields revealed a negative horizontal tilt of the trough in 500 hPa, influenced by intense convection as the system develops. Besides, it pointed to a more pronounced jet stream in intense explosive cyclones and more prominent diffluence in non-intense cases. Since the NCEP2 reanalysis detected fewer cases (and only 2 intense) than MERRA-2, it was considered that the former is less suited to the analysis of this type of event.

Expert Multinational Consensus Statement for Total Intravenous Anaesthesia (TIVA) Using the Delphi Method.

Introduction: The use of total intravenous anaesthesia (TIVA) has been well established as an anaesthetic technique over the last few decades. Significant variation in practice exists however, and volatile agents are still commonly used. This study aims to determine the motivations and barriers for using TIVA over the use of volatile agents by analysing the opinion of several international anaesthetists with specific expertise or interests. Methods and participants: The Delphi method was used to gain the opinions of expert panellists with a range of anaesthetic subspecialty expertise. Twenty-nine panellists were invited to complete three survey rounds containing statements regarding the use of TIVA. Anonymised data were captured through the software REDCap and analysed for consensus and prioritisation across statements. Starting with 12 statements, strong consensus was defined as ≥75% agreement. Stability was assessed between rounds. Results: Strong consensus was achieved for four statements regarding considerations for the use of TIVA. These statements addressed whether TIVA is useful in paediatric anaesthesia, the importance of TIVA in reducing the incidence of postoperative nausea and vomiting, its positive impact on the environment and effect on patient physiology, such as airway and haemodynamic control. Conclusions: Using the Delphi method, this international consensus showed that cost, lack of familiarity or training and the risk of delayed emergence are not considered obstacles to TIVA use. It appears, instead, that the primary motivations for its adoption are the impact of TIVA on patient experience, especially in paediatrics, and the benefit to the overall procedure outcome. The effect of TIVA on postoperative nausea and vomiting and patient physiology, as well as improving its availability in paediatrics were considered as priorities. We also identified areas where the debate remains open, generating new research questions on geographical variation and the potential impact of local availability of monitoring equipment.

Foliculitis pseudolinfomatosa de McNutt (localización nasal) / McNutt's pseudolymphomatous folliculitis (nasal located)

La foliculitis pseudolinfomatosa, descripta por McNutt en 1986, es una afección de etiología desconocida y poco frecuente, que simula un linfoma cutáneo tanto por su clínica como por su histología. Se presenta como una lesión nodular solitaria, eritematosa, de 0,5 hasta 3cm, de crecimiento rápido, sobre todo en la cara, en personas de 40 a 60 años, con una histopatología caracterizada por un infiltrado linfocitario B yT perifocular, y células dendríticas positivas en la inmunohistoquímica para S100yCD1a. Su curso es benigno, muchas veces autolimitado. Se expone el caso de una paciente con una particular forma clínica de pseudolinforma.

Pseudolymphomatous folliculitis, described by McNutt in 1986, is a non-frequent entity of unknown etiology that simulates a cutaneous lymphoma, both clinically and histologically. It shows as a solitary erythematous nodular lesion of 0.5 to 3 cm, with a rapid growth, mainly on the face, in people aged 40 to 60 years, and histopathology characterized by a perifollicular B and T lymphocytic infiltrate, and positive dendritic cells for immunohistochemistry S100 and CD1a. Its course is benign, often self-limited. The case of a patient with a particular clinical form of pseudolymphoma is presented.

[Commercial airline routes and international distribution of COVID-19]. / Rutas aerocomerciales y distribución internacional de COVID-19.

COVID-19 has had a rapid dissemination. Departing from China, the virus has traveled all around the world. With the use of accurate mathematical models, the global spread of the disease was anticipated. Some additional information to these predictive models could be provided by the comparison of freely available maps depicting commercial air travel routes and disease spread. This analysis informs on what seems to be a direct relationship between the initially unequal worldwide distribution of the disease and the density of the commercial air traffic. This comparison may also help to identify international distributional hubs of the disease out of China. The observation of this easily accessible information may contribute to the understanding of COVID-19 spill over and help health control policies to better focus on the spread of this and other aggressively spreading respiratory infectious diseases.

La novel enfermedad COVID-19 ha tenido una rápida diseminación. Desde China, el virus viajó por todo el mundo. El potencial de la propagación global de COVID-19 fue anticipado y calculado mediante el uso de modelos matemáticos precisos. A estos modelos predictores se puede agregar información obtenida mediante la comparación de mapas gratuitos que representan la propagación internacional de la enfermedad y la densidad de las rutas aerocomerciales. Este análisis proporciona información de lo que parece ser una relación directa entre la distribución mundial inicial desigual de la enfermedad y la densidad del flujo aerocomercial. Esta comparación también puede estar sugiriendo la presencia de centros internacionales de distribución secundaria fuera de China. Con esta información de rápido acceso se puede contribuir a la mejor comprensión del derrame internacional de COVID-19 y orientar los esfuerzos de las políticas de salud para el control de esta y otras enfermedades infecciosas respiratorias agresivas.