Performance and Reliable Operation of Physiological Controllers Under Various Cardiovascular Models: In Silico and In Vitro Study.

The evaluation of control schemes for left ventricular assist devices (LVADs) requires the utilization of an appropriate model of the human cardiovascular system. Given that different patients and experimental data yield varying performance of the cardiovascular models (CVMs) and their respective parameters, it becomes crucial to assess the reliable operation of controllers. This study aims to assess the performance and reliability of various LVAD controllers using two state-of-the-art CVMs, with a specific focus on the impact of interpatient variability. Extreme test cases were employed for evaluation, incorporating both in silico and in vitro experiments. The differences observed in response between the studied CVMs can be attributed to variations in their structures and parameters. Specifically, the model with smaller compartments exhibits higher overload rates, whereas the other model demonstrates increased sensitivity to changes in preload and afterload, resulting in more frequent suction events (34.2% vs. 8.5% for constant speed mode). These findings along with the varying response of the tested controllers highlight the influence of the selected CVM emphasizing the need to test each LVAD controller with multiple CVMs or, at least, a range of parameter sets. This approach ensures sufficient evaluation of the controller's efficacy in addressing interpatient variability.

Fantastical phenomena, illustratedThe Warped Side of Our Universe Kip Thorne and Lia Halloran Liveright, 2023. 240 pp.

An astrophysicist and an artist craft evocative portraits of warping spacetime.

Critical Point Drying of Graphene Field-Effect Transistors Improves Their Electric Transport Characteristics.

A critical point drying (CPD) technique is reported with supercritical CO2 as a cleaning step for graphene field-effect transistors (GFETs) microfabricated on oxidized Si wafers, which results in an increase of the field-effect mobility and a decrease of the impurity doping. It is shown that the polymeric residues remaining on graphene after the transfer process and device microfabrication are significantly reduced after the CPD treatment. Moreover, the CPD effectively removes ambient adsorbates such as water therewith reducing the undesirable p-type doping of the GFETs. It is proposed that CPD of electronic, optoelectronic, and photonic devices based on 2D materials as a promising technique to recover their intrinsic properties after the microfabrication in a cleanroom and after storage at ambient conditions.

Effects of the 2018 European heatwave and drought on coastal biogeochemistry in the German Bight.

In 2018, Europe experienced an unprecedented heatwave and drought, especially in central and northern Europe, which caused decreased terrestrial production and affected ecosystem health. In this study, the effects of this event on the marine environment are investigate, with a focus on the biogeochemical response in the German Bight of the North Sea. Using time series data from FerryBoxes, research cruises, monitoring programs and remote sensing we compare conditions in 2018 to climatological values. We find that (1) the heatwave caused rapid warming of surface waters, (2) the drought reduced river discharge and nutrient loads to the coast, and (3) these combined effects altered coastal biogeochemistry and productivity. During 2018, both water discharge and nutrient loads from rivers discharging into the German Bight were below the seasonally variable 10th percentile from March onward. Throughout the study domain, water temperature was near or below that threshold in March 2018, but higher than in other years during May 2018, representing not only a heat wave, but also the fastest spring warming on record. This extreme warming period saw concurrent high peaks in chlorophyll a, dissolved oxygen and pH, consistent with the development of a strong spring bloom. It appears that productivity was above 75th percentile of the 21-year record in most of the nearshore region, while offshore it was widely below the 25th percentile in 2018. The drought-related low discharge limited nutrient supply from the rivers, but likely increased water residence time nearshore, where a surge in primary production with efficient nutrient utilization during the spring depleted nutrients available for transport offshore. There, the heatwave-related rapid warming of surface water resulted in the establishment of a stable thermal water column stratification, hindering vertical nutrient supply to the surface layer during the summer.

Energy poverty: an overlooked determinant of health and climate resilience in Canada.

OBJECTIVE: Despite Canada being an important energy producer, not all Canadians can access or afford adequate levels of energy services at home to meet their needs, maintain healthy indoor temperatures, and live a decent life-a situation known as energy poverty. Depending on the measure, 6-19% of Canadian households face energy poverty. Health risks associated with energy poverty are documented in countries with milder climates. This study explores, for the first time in the Canadian context, the association between energy poverty and health. METHODS: Cross-sectional data are from the 2018 Canadian Housing Survey. Analyses are conducted on a sample weighted to represent 14 million Canadian households. The associations between expenditure-based and self-reported measures of energy poverty and self-rated general and mental health were assessed using logistic regression models, adjusted for potential confounding variables. RESULTS: The odds of rating one's general (OR: 1.48; 95%CI: 1.29, 1.70) and mental (OR: 1.21; 1.04, 1.41) health as poor are significantly higher for Canadian adults in households with a high share of energy expenditure to income. The likelihood of poor general and mental health was significantly higher for those dissatisfied with the energy efficiency of their dwelling, and with their ability to maintain a comfortable temperature both in the winter and in the summer. CONCLUSION: Exposure to energy poverty is associated with significantly increased likelihood of poor general and mental health. Given the high proportion of Canadian households facing energy poverty, with demonstrated implications for population health, tackling energy poverty is essential for an equitable energy transition and for climate resilience.

RéSUMé: OBJECTIF: Bien que le Canada soit un important producteur d'énergie, entre 6 % et 19 % des ménages canadiens, selon la mesure retenue, sont en précarité énergétique, une situation qui survient lorsqu'un ménage n'a pas les moyens ou l'accès à des services énergétiques résidentiels adéquats pour maintenir une température ambiante confortable, répondre à ses besoins et vivre dans la dignité. Les risques socio-sanitaires associés à la précarité énergétique sont documentés dans des pays au climat tempéré. Cette étude explore, pour la première fois dans le contexte canadien, l'association entre la précarité énergétique et la santé. MéTHODES: Les données transversales proviennent de l'Enquête canadienne sur le logement de 2018. Les associations entre différentes mesures de précarité énergétique (mesures basées sur les dépenses des ménages et auto-rapportées) et la santé générale et mentale perçue sont estimées à l'aide de modèles de régression logistique ajustés pour des variables de confusion potentielles. Les analyses sont réalisées sur un échantillon pondéré pour représenter 14 millions de ménages. RéSULTATS: Les probabilités de déclarer une mauvaise santé générale (OR : 1,48; IC95% : 1,29-1,70) et mentale (OR : 1,21; 1,04-1,41) sont significativement plus élevées pour les adultes canadiens dont le ménage consacre une part importante de son revenu aux coûts énergétiques. Elles sont aussi significativement plus élevées pour ceux qui déclarent être insatisfaits avec l'efficacité énergétique de leur logement et de leur capacité à maintenir une température confortable en hiver et en été. CONCLUSION: Vivre en situation de précarité énergétique est associée à des probabilités accrues de déclarer une mauvaise santé générale et mentale chez les adultes canadiens. En raison de la proportion élevée de ménages canadiens confrontés à la précarité énergétique et des effets socio-sanitaires que cette situation engendre, lutter contre la précarité énergétique est essentiel pour une transition énergétique équitable et pour la résilience climatique.

Safety and effectiveness of indirect radiofrequency ablation (closure FAST) of incompetent great saphenous veins with Type I aneurysms: Long-term results radiofrequency ablation for saphenous aneurysms.

BACKGROUND: Assess the safety and effectiveness of indirect radiofrequency ablation (RFA, Closure FAST) for the treatment of incompetent great saphenous veins (GSVs) with type 1 aneurysms. METHODS: This was a retrospective analysis performed in three centers (2007-2021). All patients presenting with saphenous aneurysms close to the junction (within 2 cm) were included. They were treated with RFA. Phlebectomies and/or sclerotherapy were performed during the same treatment session. Duplex ultrasound (DUS) was performed early after the procedure and then, more than a year later. RESULTS: Eight patients (11 limbs) were included between June 2007 and May 2021 with a median diameter of the GSV aneurysm 21 mm (IQR 17.2-23.4). No severe adverse events occurred apart from one endovenous heat-induced thrombosis (EHIT) class III (9.1%). After more than a year (mean 7.2 ± 4.2, median 8 years), none of the aneurysms was present on DUS and the truncal obliteration rate was 100%. CONCLUSION: RFA appears to be a safe and effective treatment for patients presenting with incompetent saphenous veins with the type 1 aneurysm.

Improving attribution of extreme heat deaths through interagency cooperation.

Attributing individual deaths to extreme heat events (EHE) in Canada and elsewhere is important for understanding the risk factors, protective interventions, and burden of mortality associated with climate change. However, there is currently no single mechanism for identifying individual deaths due to EHE and different agencies have taken different approaches, including (1) vital statistics coding based on medical certificates of death, (2) probabilistic methods, and (3) enhanced surveillance. The 2018 EHE in Montréal provides an excellent case study to compare EHE deaths identified by these different approaches. There were 353 deaths recorded in the vital statistics data over an 8-day period, of which 102 were potentially attributed to the EHE by at least one approach and 251 were not attributed by any approach. Only nine of the 102 deaths were attributed to the EHE by all three approaches, 23 were attributed by two approaches, and 70 were attributed by only one approach. Given that there were approximately 50 excess deaths during the EHE, it remains unclear exactly which of the total 353 deaths should be attributed to the extreme temperatures. These results highlight the need for a more systematic and cooperative approach to EHE mortality in Canada, which will continue to increase as the climate changes.

RéSUMé: L'attribution des décès individuels aux épisodes de chaleur accablante (ECA) au Canada et ailleurs est importante pour comprendre les facteurs de risque, les interventions de protection et le fardeau de la mortalité associés aux changements climatiques. Cependant, il n'existe actuellement aucun mécanisme unique pour identifier les décès individuels dus à l'ECA et différentes agences ont adopté différentes approches, notamment (1) le codage des statistiques de l'état civil basé sur les certificats médicaux de décès, (2) des méthodes probabilistes et (3) une surveillance renforcée. L'ECA 2018 à Montréal fournit une excellente étude de cas pour comparer les décès ECA identifiés par ces différentes approches. Il y a eu 353 décès enregistrés dans les données des statistiques de l'état civil sur une période de 8 jours, dont 102 ont été potentiellement attribués à l'ECA par au moins une approche et 251 n'ont été attribués par aucune approche. Seuls neuf des 102 décès ont été attribués à l'ECA par les trois approches, 23 ont été attribués par deux approches et 70 ont été attribués par une seule approche. Étant donné qu'il y a eu environ 50 décès supplémentaires pendant l'ECA, on ne sait pas exactement lequel des 353 décès au total doit être attribué aux températures extrêmes. Ces résultats soulignent la nécessité d'une approche plus systématique et coopérative de la mortalité ECA au Canada, qui continuera d'augmenter à mesure que le climat change.

Two-Dimensional Photosensitizer Nanosheets via Low-Energy Electron Beam Induced Cross-Linking of Self-Assembled RuII Polypyridine Monolayers.

Artificial photosynthesis for hydrogen production is an important element in the search for green energy sources. The incorporation of photoactive units into mechanically stable 2D materials paves the way toward the realization of ultrathin membranes as mimics for leaves. Here we present and compare two concepts to introduce a photoactive RuII polypyridine complex into ≈1 nm thick carbon nanomembranes (CNMs) generated by low-energy electron irradiation induced cross-linking of aromatic self-assembled monolayers. The photoactive units are either directly incorporated into the CNM scaffold or covalently grafted to its surface. We characterize RuII CNMs using X-ray photoelectron, surface-enhanced Raman, photothermal deflection spectroscopy, atomic force, scanning electron microscopy, and study their photoactivity in graphene field-effect devices. Therewith, we explore the applicability of low-energy electron irradiation of metal complexes for photosensitizer nanosheet formation.

Acquired epidermodysplasia verruciformis in a renal transplant patient: a case report.

Acquired epidermodysplasia verruciformis is a rare disease. It can develop in immunocompromised patients due to infection with human papillomaviruses. Because such patients are at high risk of developing cutaneous squamous cell carcinoma, timely diagnosis and regular monitoring of the patient is essential. Here we present the case of a 46-year-old male patient with acquired epidermodysplasia verruciformis occurring 5 years after a kidney transplantation. A skin biopsy detected human papillomavirus genotype 20 with low oncogenic potential. Accordingly, a follow-up interval of 1 year was determined. He was instructed to follow strict photoprotection and to visit earlier if atypical lesions appeared. Overall, our case emphasizes the consideration of possible squamous cell carcinoma in such patients and the importance of appropriate preventive measures.

Eruptive facial lentiginosis-like repigmentation in a patient with longstanding generalized vitiligo without a detectable trigger.

Spontaneous appearance of hyperpigmented macules on chronic vitiligo lesions is a very rare phenomenon, which is described as eruptive lentiginosis. We describe the case of a patient with chronic non-segmental generalized vitiligo who presented with a sudden onset of hyperpigmented macules on depigmented areas of the face. A biopsy showed pigmented basal keratinocytes in the interfollicular epidermis, and immunohisochemistry with anti-SOX10 antibodies showed nuclei of single melanocytes. This case shows that even long-standing depigmented vitiligo lesions may contain functional melanocytes or their precursors.

Extreme Heat and Cardiovascular Health: What a Cardiovascular Health Professional Should Know.

As global temperatures continue to rise, extreme heat events are becoming more frequent and intense. Extreme heat affects cardiovascular health as it is associated with a greater risk of adverse cardiovascular events, especially for adults with preexisting cardiovascular diseases. Nonetheless, the pathophysiology underlying the association between extreme heat and cardiovascular risk remains understudied. Furthermore, specific recommendations to mitigate the effects of extreme heat on cardiovascular health remain limited to guide clinical practice within the context of a warming climate. The overall objective of this review article is to raise awareness that extreme heat poses a risk for cardiovascular health. Specifically, the review discusses why cardiovascular healthcare professionals should care about extreme heat, how extreme heat affects cardiovascular health, and recommendations to minimise the cardiovascular consequences of extreme heat. Future research directions are also provided to further our understating of the cardiovascular health consequences of extreme heat. A better awareness and understanding of the cardiovascular consequences of extreme heat will help cardiovascular health professionals assess the risk and optimise the care of their patients exposed to an increasingly warm climate.

Negotiating Safety and Wellbeing: The Collaboration Between Faith-Based Communities and Public Health During the COVID-19 Pandemic.

The COVID-19 pandemic led to lockdown measures where congregational faith-based activities were prohibited. With time, the collateral impacts of confinement emerged as priorities, and impositions had to be balanced with the collaboration of the population. In this process, faith-based organizations played a key role in encouraging their congregations to adhere to lockdown measures while fostering their mental wellbeing and resilience. This paper describes the process of establishing a collaborative negotiation among the Montreal Regional Public Health Unit, the police, and the Muslim and Jewish communities, examining the role of mediation in this context. Despite some obstacles, such as communication difficulties and decision-making limitations, the collaborative approach seems to buffer the escalation of intercommunity tension and to promote communities' commitment to physical distancing measures and should be considered in times of pandemic for a more inclusive public health approach.

Abundance and characteristics of microfibers detected in sediment trap material from the deep subtropical North Atlantic Ocean.

Plastics and microplastics increasingly gain importance due to their perils and wide distribution in the marine environment. Microfibers account for the largest percentage of anthropogenic-induced microparticles, which inter alia, consist of plastic, and are found in deep-sea sediments. However, the sinking of fibers from the surface through the water column to the seafloor is still poorly understood. The present study investigates microfibers extracted from sediment trap samples, which were deployed in the North Atlantic Subtropical Gyre (NASG). The average result of eleven analyzed samples showed 913 microfibers per gram of collected particle flux material, with a predominant fiber length shorter than 1 mm (75.6%) and a distribution maximum between 0.2 and 0.4 mm. Further, the average number of microfibers found in this study was used to derive microfiber fluxes for the NASG based on the deployment time of the sediment trap. Extrapolating the computed flux of 94 microfibers m-2 day-1 to the entire NASG area would correspond to a total microfiber mass flux of 9800 t a-1 or 73 × 1013 microfibers a-1 of sinking microfibers through the water column. These findings offer an extended application of sediment traps to monitor microfiber fluxes, which reveals the opportunity to investigate the mechanism driving sinking of microfibers and microplastics into the deep open ocean.

Optically Triggered Control of the Charge Carrier Density in Chemically Functionalized Graphene Field Effect Transistors.

Field effect transistors (FETs) based on 2D materials are of great interest for applications in ultrathin electronic and sensing devices. Here we demonstrate the possibility to add optical switchability to graphene FETs (GFET) by functionalizing the graphene channel with optically switchable azobenzene molecules. The azobenzene molecules were incorporated to the GFET channel by building a van der Waals heterostructure with a carbon nanomembrane (CNM), which is used as a molecular interposer to attach the azobenzene molecules. Under exposure with 365 nm and 455 nm light, azobenzene molecules transition between cis and trans molecular conformations, respectively, resulting in a switching of the molecular dipole moment. Thus, the effective electric field acting on the GFET channel is tuned by optical stimulation and the carrier density is modulated.

Making sense of what exactly public health does: a typology of public health interventions.

SETTING: Montréal. INTERVENTION: The lack of common knowledge about what public health does is a hindrance to its recognition and capacity to act. Montréal's regional public health department set an explicit goal to clarify and better communicate its specific contributions when it developed its 2016-2021 action plan. This article briefly describes the efforts made to classify public health practice, introduces a typology of public health interventions and discusses its application and benefits. OUTCOMES: The typology that was developed defines 29 types of interventions grouped into four categories: direct action targeting the population; advocacy (persuading partners to take action); support (helping partners take action); collaboration (taking action with partners). The analysis of Montreal's most recent action plan, completely drafted in terms of the typology, provides an insightful characterization of public health practice. Globally, four out of five interventions target partners (indirect), with more than half falling within the support category. Other indirect interventions are divided almost equally between advocacy and collaboration. Following a rigorous planning process and enforcing the use of the typology also had a significant structuring effect on the organization and its teams and enabled greater synergy with partners from other sectors. IMPLICATIONS: Very few people are familiar with everything public health does, sometimes not even the responsible political decision-makers. This situation poses a threat to the survival of its prevention mission. The typology of public health interventions is an innovative tool that can be used to better inform the public and decision-makers.

Nonlinear Dynamics of Preheating after Multifield Inflation with Nonminimal Couplings.

We study the postinflation dynamics of multifield models involving nonminimal couplings using lattice simulations to capture significant nonlinear effects like backreaction and rescattering. We measure the effective equation of state and typical timescales for the onset of thermalization, which could affect the usual mapping between predictions for primordial perturbation spectra and measurements of anisotropies in the cosmic microwave background radiation. For large values of the nonminimal coupling constants, we find efficient particle production that gives rise to nearly instantaneous preheating. Moreover, the strong single-field attractor behavior that was previously identified persists until the end of preheating, thereby suppressing typical signatures of multifield models. We therefore find that predictions for primordial observables in this class of models retain a close match to the latest observations.