Effect of compressive force on the performance of a proton exchange membrane fuel cell

The effect of the compressive force on the performance of a proton exchange membrane fuel cell has been examined experimentally. The performance has been evaluated on two polarization regions of the cell: ohmic and mass transport. Cell voltage and current density as a function of pressure were measured under constant load and various inlet air humidity conditions. The pressure distribution on the surface of the gas diffusion layer was measured using a pressure detection film and the results show that increasing the pressure improves the performance of the cell. The improvement of the cell voltage in the ohmic region was found to be greater than that in the mass transport region, whereas for the cell current density, the mass transport region exhibited higher change. The increase in the cell specific power in the ohmic and mass transport regions, as pressure increases from 0 to 2MNm-2, is estimated to be 9 and 18mWcm−2, respectively. However, the fuel cell performance in these two regions declined dramatically when excessive pressure (≥5 MNm−2) was applied. The mass transport region proved to be more susceptible to this sharp decline under excessive pressure than the ohmic region

Exposure to moral stressors and associated outcomes in healthcare workers:Prevalence, correlates, and impact on job attrition

Introduction: Healthcare workers (HCWs) often experience morally challenging situations in their workplaces that may contribute to job turnover and compromised well-being. This study aimed to characterize the nature and frequency of moral stressors experienced by HCWs during the COVID-19 pandemic, examine their influence on psychosocial-spiritual factors, and capture the impact of such factors and related moral stressors on HCWs’ self-reported job attrition intentions.Methods: A sample of 1204 Canadian HCWs were included in the analysis through a web-based survey platform whereby work-related factors (e.g. years spent working as HCW, providing care to COVID-19 patients), moral distress (captured by MMD-HP), moral injury (captured by MIOS), mental health symptomatology, and job turnover due to moral distress were assessed.Results: Moral stressors with the highest reported frequency and distress ratings included patient care requirements that exceeded the capacity HCWs felt safe/comfortable managing, reported lack of resource availability, and belief that administration was not addressing issues that compromised patient care. Participants who considered leaving their jobs (44%; N = 517) demonstrated greater moral distress and injury scores. Logistic regression highlighted burnout (AOR = 1.59; p &lt; .001), moral distress (AOR = 1.83; p &lt; .001), and moral injury due to trust violation (AOR = 1.30; p = .022) as significant predictors of the intention to leave one’s job.Conclusion: While it is impossible to fully eliminate moral stressors from healthcare, especially during exceptional and critical scenarios like a global pandemic, it is crucial to recognize the detrimental impacts on HCWs. This underscores the urgent need for additional research to identify protective factors that can mitigate the impact of these stressors.Introducción: Los trabajadores de la salud (TS) a menudo experimentan situaciones moralmente desafiantes en sus lugares de trabajo que pueden contribuir a la rotación laboral y comprometer su bienestar. Este estudio tuvo como objetivo caracterizar la naturaleza y frecuencia de los estresores morales experimentados por los TS durante la pandemia por COVID-19, examinar su influencia en los factores psicosociales-espirituales y capturar el impacto de dichos factores y los estresores morales relacionados a las intenciones de abandono laboral de los TS.Métodos: Se incluyó en el análisis una muestra de 1.204 TS canadienses a través de una encuesta en plataforma web en la que se analizaron factores relacionados con el trabajo (p. ej., años trabajados como TS, brindando atención a pacientes con COVID-19), angustia moral (evaluado con MMD-HP), daño moral (evaluado con MIOS), sintomatología de salud mental y rotación laboral debido a angustia moral.Resultados: Los estresores morales con mayor frecuencia reportados y tasas de angustia incluyeron requerimientos de atención al paciente que excedieron la capacidad en la que los TS se sentían seguros/cómodos de manejarlos, falta de disponibilidad de recursos y la creencia de que la administración no estaba abordando los problemas que comprometían la atención al paciente. Los participantes que consideraron dejar sus trabajos (44%; N = 517) demostraron mayores puntuaciones de angustia y daño moral. La regresión logística destacó el burnout (AOR = 1,59; p &lt; 0,001), la angustia moral (AOR = 1,83; p &lt; 0,001) y el daño moral debido a la violación de la confianza (AOR = 1,30; p = 0,022) como predictores significativos asociados a la intención de dejar el trabajo.Conclusión: Si bien, es imposible eliminar por completo los estresores morales de la atención sanitaria, especialmente durante escenarios críticos y excepcionales como una pandemia global, es crucial reconocer los impactos perjudiciales para los TS. Esto subraya la necesidad urgente de realizar investigaciones adicionales para identificar factores protectores que puedan mitigar el impacto de estos factores estresantes.</div

Exposure to moral stressors and associated outcomes in healthcare workers:Prevalence, correlates, and impact on job attrition

Introduction: Healthcare workers (HCWs) often experience morally challenging situations in their workplaces that may contribute to job turnover and compromised well-being. This study aimed to characterize the nature and frequency of moral stressors experienced by HCWs during the COVID-19 pandemic, examine their influence on psychosocial-spiritual factors, and capture the impact of such factors and related moral stressors on HCWs’ self-reported job attrition intentions.Methods: A sample of 1204 Canadian HCWs were included in the analysis through a web-based survey platform whereby work-related factors (e.g. years spent working as HCW, providing care to COVID-19 patients), moral distress (captured by MMD-HP), moral injury (captured by MIOS), mental health symptomatology, and job turnover due to moral distress were assessed.Results: Moral stressors with the highest reported frequency and distress ratings included patient care requirements that exceeded the capacity HCWs felt safe/comfortable managing, reported lack of resource availability, and belief that administration was not addressing issues that compromised patient care. Participants who considered leaving their jobs (44%; N = 517) demonstrated greater moral distress and injury scores. Logistic regression highlighted burnout (AOR = 1.59; p &lt; .001), moral distress (AOR = 1.83; p &lt; .001), and moral injury due to trust violation (AOR = 1.30; p = .022) as significant predictors of the intention to leave one’s job.Conclusion: While it is impossible to fully eliminate moral stressors from healthcare, especially during exceptional and critical scenarios like a global pandemic, it is crucial to recognize the detrimental impacts on HCWs. This underscores the urgent need for additional research to identify protective factors that can mitigate the impact of these stressors.Introducción: Los trabajadores de la salud (TS) a menudo experimentan situaciones moralmente desafiantes en sus lugares de trabajo que pueden contribuir a la rotación laboral y comprometer su bienestar. Este estudio tuvo como objetivo caracterizar la naturaleza y frecuencia de los estresores morales experimentados por los TS durante la pandemia por COVID-19, examinar su influencia en los factores psicosociales-espirituales y capturar el impacto de dichos factores y los estresores morales relacionados a las intenciones de abandono laboral de los TS.Métodos: Se incluyó en el análisis una muestra de 1.204 TS canadienses a través de una encuesta en plataforma web en la que se analizaron factores relacionados con el trabajo (p. ej., años trabajados como TS, brindando atención a pacientes con COVID-19), angustia moral (evaluado con MMD-HP), daño moral (evaluado con MIOS), sintomatología de salud mental y rotación laboral debido a angustia moral.Resultados: Los estresores morales con mayor frecuencia reportados y tasas de angustia incluyeron requerimientos de atención al paciente que excedieron la capacidad en la que los TS se sentían seguros/cómodos de manejarlos, falta de disponibilidad de recursos y la creencia de que la administración no estaba abordando los problemas que comprometían la atención al paciente. Los participantes que consideraron dejar sus trabajos (44%; N = 517) demostraron mayores puntuaciones de angustia y daño moral. La regresión logística destacó el burnout (AOR = 1,59; p &lt; 0,001), la angustia moral (AOR = 1,83; p &lt; 0,001) y el daño moral debido a la violación de la confianza (AOR = 1,30; p = 0,022) como predictores significativos asociados a la intención de dejar el trabajo.Conclusión: Si bien, es imposible eliminar por completo los estresores morales de la atención sanitaria, especialmente durante escenarios críticos y excepcionales como una pandemia global, es crucial reconocer los impactos perjudiciales para los TS. Esto subraya la necesidad urgente de realizar investigaciones adicionales para identificar factores protectores que puedan mitigar el impacto de estos factores estresantes.</div

Quantum optical time-of-arrival model in three dimensions

We investigate the three-dimensional formulation of a recently proposed operational arrival-time model. It is shown that within typical conditions for optical transitions the results of the simple one-dimensional version are generally valid. Differences that may occur are consequences of Doppler and momentum-transfer effects. Ways to minimize these are discussed.Comment: 14 pages, 5 figure

A rare combination of an endocrine tumour of the common bile duct and a follicular lymphoma of the ampulla of Vater: a case report and review of the literature

Carcinoid tumours of the common bile duct represent an extremely rare entity. Similarly, primary follicular lymphomas of the ampulla of Vater constitute an infrequent neoplasia. Herein, we report the first case of a synchronous development of a carcinoid tumour of the common bile duct and an ampullary follicular lymphoma that was treated surgically with a Whipple's procedure, due to inability to establish definitive preoperative diagnosis despite the extensive diagnostic investigation

Firefly Luciferase and Rluc8 Exhibit Differential Sensitivity to Oxidative Stress in Apoptotic Cells

Over the past decade, firefly Luciferase (fLuc) has been used in a wide range of biological assays, providing insight into gene regulation, protein-protein interactions, cell proliferation, and cell migration. However, it has also been well established that fLuc activity can be highly sensitive to its surrounding environment. In this study, we found that when various cancer cell lines (HeLa, MCF-7, and 293T) stably expressing fLuc were treated with staurosporine (STS), there was a rapid loss in bioluminescence. In contrast, a stable variant of Renilla luciferase (RLuc), RLuc8, exhibited significantly prolonged functionality under the same conditions. To identify the specific underlying mechanism(s) responsible for the disparate sensitivity of RLuc8 and fLuc to cellular stress, we conducted a series of inhibition studies that targeted known intracellular protein degradation/modification pathways associated with cell death. Interestingly, these studies suggested that reactive oxygen species, particularly hydrogen peroxide (H2O2), was responsible for the diminution of fLuc activity. Consistent with these findings, the direct application of H2O2 to HeLa cells also led to a reduction in fLuc bioluminescence, while H2O2 scavengers stabilized fLuc activity. Comparatively, RLuc8 was far less sensitive to ROS. These observations suggest that fLuc activity can be substantially altered in studies where ROS levels become elevated and can potentially lead to ambiguous or misleading findings

Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

International audienceThe Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at −15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under light dust loadings. These results provide insights into boundary layer and dust processes in the SHL region – a region of substantial global climatic importance

Contribution of Microbe-Mediated Processes in Nitrogen Cycle to Attain Environmental Equilibrium

Nitrogen (N), the most important element, is required by all living organisms for the synthesis of complex organic molecules like amino acids, proteins, lipids etc. Nitrogen cycle is considered to be the most complex yet arguably important cycle next to carbon cycle. Nitrogen cycle includes oxic and anoxic reactions like organic N mineralization, ammonia assimilation, nitrification denitrification, anaerobic ammonium oxidation (anammox), dissimilatory nitrate reduction to ammonium (DNRA), comammox, codenitrification etc. Nitrogen cycling is one of the most crucial processes required for the recycling of essential chemical requirements on the planet. Soil microorganisms not only improve N-cycle balance but also pave the way for sustainable agricultural practices, leading to improved soil properties and crop productivity as most plants are opportunistic in the uptake of soluble or available forms of N from soil. Microbial N transformations are influenced by plants to improve their nutrition and vice versa. Diverse microorganisms, versatile metabolic activities, and varied biotic and abiotic conditions may result in the shift in the equilibrium state of different N-cycling processes. This chapter is an overview of the mechanisms and genes involved in the diverse microorganisms associated in the operation of nitrogen cycle and the roles of such microorganisms in different agroecosystems