Hygroscopic and chemical characterisation of Po Valley aerosol

Continental summer-time aerosol in the Italian Po Valley was characterised in terms of hygroscopic properties and the influence of chemical composition therein. Additionally, the ethanol affinity of particles was analysed. The campaign-average minima in hygroscopic growth factors (HGFs, at 90% relative humidity) occurred just before and during sunrise from 03:00 to 06:00 LT (all data are reported in the local time), but, more generally, the hygroscopicity during the whole night is very low, particularly in the smaller particle sizes. The average HGFs recorded during the low HGF period were in a range from 1.18 (for the smallest, 35nm particles) to 1.38 (for the largest, 165 nm particles). During the day, the HGF gradually increased to achieve maximum values in the early afternoon hours 12:00–15:00, reaching 1.32 for 35 nm particles and 1.46 for 165 nm particles. Two contrasting case scenarios were encountered during the measurement period: Case 1 was associated with westerly air flow moving at a moderate pace and Case 2 was associated with more stagnant, slower moving air from the north-easterly sector. Case 1 exhibited weak diurnal temporal patterns, with no distinct maximum or minimum in HGF or chemical composition, and was associated with moderate non-refractory aerosol mass concentrations (for 50% size cut at 1 μ) of the order of 4.5 μg m⁻³. For Case 1, organics contributed typically 50% of the mass. Case 2 was characterised by >9.5 μg m⁻³ total non-refractory mass (<1 μ) in the early morning hours (04:00), decreasing to ~3 μg m⁻³ by late morning (10:00) and exhibited strong diurnal changes in chemical composition, particularly in nitrate mass but also in total organic mass concentrations. Specifically, the concentrations of nitrate peaked at night-time, along with the concentrations of hydrocarbon-like organic aerosol (HOA) and of semi-volatile oxygenated organic aerosol (SV-OOA). In general, organic growth factors (OGFs) followed a trend which was opposed to HGF and also to the total organic mass as measured by the aerosol mass spectrometer. The analysis of the HGF probability distribution function (PDF) reveals an existence of a predominant "more hygroscopic" (MH) mode with HGF of 1.5 around noon, and two additional modes: one with a "less hygroscopic" (LH) HGF of 1.26, and another with a "barely hygroscopic" (BH) mode of 1.05. Particles sized 165 nm exhibited moderate diurnal variability in HGF, ranging from 80% at night to 95% of "more hygroscopic" growth factors (i.e. HGFs 1.35–1.9) around noon. The diurnal changes in HGF progressively became enhanced with decreasing particle size, decreasing from 95% "more hygroscopic" growth factor fraction at noon to 10% fraction at midnight, while the "less hygroscopic" growth factor fraction (1.13–1.34) increased from 5% at noon to > 60% and the "barely hygroscopic" growth factor fraction (1.1–1.2) increased from less than 2% at noon to 30% at midnight. Surprisingly, the lowest HGFs occurred for the period when nitrate mass reached peak concentrations (Case 2). We hypothesised that the low HGFs of nitrate-containing particles can be explained by a) an organic coating suppressing the water-uptake, and/or by b) the existence of nitrates in a less hygroscopic state, e.g. as organic nitrates. The latter hypothesis allows us to explain also the reduced OGFs observed during the early morning hours (before dawn) when nitrate concentrations peaked, based on the evidence that organic nitrates have significant lower ethanol affinity than other SV-OOA compounds

Sex and gender in cardiovascular medicine: presentation and outcomes of acute coronary syndrome.

Although health disparities in women presenting with acute coronary syndrome (ACS) have received growing attention in recent years, clinical outcomes from ACS are still worse for women than for men. Women continue to experience higher patient and system delays and receive less aggressive invasive treatment and pharmacotherapies. Gender- and sex-specific variables that contribute to ACS vulnerability remain largely unknown. Notwithstanding the sex differences in baseline coronary anatomy and function, women and men are treated the same based on guidelines that were established from experimental and clinical trial data over-representing the male population. Importantly, younger women have a particularly unfavourable prognosis and a plethora of unanswered questions remains in this younger population. The present review summarizes contemporary evidence for gender and sex differences in vascular biology, clinical presentation, and outcomes of ACS. We further discuss potential mechanisms and non-traditional risk conditions modulating the course of disease in women and men, such as unrecognized psychosocial factors, sex-specific vascular and neural stress responses, and the potential impact of epigenetic modifications

Hyperglycaemia but not hyperlipidaemia causes beta cell dysfunction and beta cell loss in the domestic cat

Aims/hypothesis: In vitro studies point to a toxic effect of high glucose and non-esterified fatty acids on beta cells. Whether elevated levels of glucose and lipids induce beta cell loss in vivo is less clear. The domestic cat has recently been proposed as a valuable animal model for human type 2 diabetes because feline diabetes shows several similarities with diabetes in humans, including obesity-induced insulin resistance, impaired beta cell function, decreased number of beta cells and pancreatic amyloid deposition. Methods: We infused healthy cats with glucose or lipids for 10days to clamp their blood concentrations at the approximate level found in untreated feline diabetes (glucose: 25-30mmol/l; triacylglycerols: 3-7mmol/l). Results: Glucose and lipid levels were adequately targeted. Plasma non-esterified fatty acids were increased by lipid infusion 1.7-fold. A dramatic and progressive decline of plasma insulin levels was observed in glucose-infused cats beginning after 2days of hyperglycaemic clamp. In contrast, plasma insulin concentration and glucose tolerance test were not affected by hyperlipidaemia. Compared with controls, glucose-infused cats had a 50% decrease in beta cells per pancreatic area. Apoptotic islet cells and cleaved caspase-3-positive beta cells were observed in glucose-infused cats only. Conclusions/interpretation: Sustained hyperglycaemia but not hyperlipidaemia induces early and severe beta cell dysfunction in cats, and excess glucose causes beta cell loss via apoptosis in vivo. Hyperglycaemic clamps in cats may provide a good model to study the pathogenesis of glucose toxicity in beta cell

Endothelial dysfunction in COVID-19: a position paper of the ESC Working Group for Atherosclerosis and Vascular Biology, and the ESC Council of Basic Cardiovascular Science

The COVID-19 pandemic is an unprecedented healthcare emergency causing mortality and illness across the world. Although primarily affecting the lungs, the SARS-CoV-2 virus also affects the cardiovascular system. In addition to cardiac effects, e.g. myocarditis, arrhythmias, and myocardial damage, the vasculature is affected in COVID-19, both directly by the SARS-CoV-2 virus, and indirectly as a result of a systemic inflammatory cytokine storm. This includes the role of the vascular endothelium in the recruitment of inflammatory leucocytes where they contribute to tissue damage and cytokine release, which are key drivers of acute respiratory distress syndrome (ARDS), in disseminated intravascular coagulation, and cardiovascular complications in COVID-19. There is also evidence linking endothelial cells (ECs) to SARS-CoV-2 infection including: (i) the expression and function of its receptor angiotensin-converting enzyme 2 (ACE2) in the vasculature; (ii) the prevalence of a Kawasaki disease-like syndrome (vasculitis) in COVID-19; and (iii) evidence of EC infection with SARS-CoV-2 in patients with fatal COVID-19. Here, the Working Group on Atherosclerosis and Vascular Biology together with the Council of Basic Cardiovascular Science of the European Society of Cardiology provide a Position Statement on the importance of the endothelium in the underlying pathophysiology behind the clinical presentation in COVID-19 and identify key questions for future research to address. We propose that endothelial biomarkers and tests of function (e.g. flow-mediated dilatation) should be evaluated for their usefulness in the risk stratification of COVID-19 patients. A better understanding of the effects of SARS-CoV-2 on endothelial biology in both the micro- and macrovasculature is required, and endothelial function testing should be considered in the follow-up of convalescent COVID-19 patients for early detection of long-term cardiovascular complications

Melt pond biogeochemistry in central Arctic: first insights from MOSAiC campaign

We undertook a melt pond survey during the international drift campaign MOSAiC Leg 5 (from 22 August to 18 September 2020) to understand variations in climate gases (CO2, CH4, N2O and DMS) and nutrients in melt ponds during the open water and freezing periods, and to study the interactions with atmospheric and ecological parameters (Figure 1a). Inside those melt ponds with a darker color, we found significant quantities of floating organic material within the pond water, along with significant further organic material settled at the bottom of the pond and frozen into the ice (Figure 1b). These floating and sedimented materials were both white and green/brown; the green/brown material was mainly composed of phytoplankton “Melosira arctica”, while the white material was composed of re-mineralized organic matter during degradation (including the remains of krill and other zooplankton). There were strong vertical gradients in physical parameters from the surface to the bottom of the melt pond (within 1 m depth): from +0.2°C to –1.5°C for temperature, from 0 to 29 psu for salinity, and 9.2 to 13.5 mg L–1 for dissolved oxygen (DO). The DO minimum layer (below 9 mg L–1) corresponded with a salinity of 25 psu, which generally occurred at approximately 0.6 m depth, and it increased to over 13 mg L–1 at the atmospheric interface. At the end of Leg 5 (mid-September 2020), these strong gradients disappeared, likely due to the mixing events during the cooling and freezing periods. Prior to and during the freezing period, CO2 flux was measured periodically within the melt pond with a floating chamber system. Because measured in situ CO2 concentration at the melt pond surface (top 10 cm) was low (321 ppm) compared to the atmosphere (approximately 400 ppm), air–to-melt pond CO2 flux was negative (melt pond was acting as a sink for atmospheric CO2) around –3.9 mmol m–2 day–1. Therefore, the melt pond water absorbs significant amounts of CO2 from the atmosphere. We also found extremely low CO2 concentrations (170 ppm) at the freshwater/seawater interface (0.6 m depth) corresponding to the same depth as the DO minimum. Therefore, we expected that if melt pond water is mixed vertically by the wind, cooling, crack formation, and ice movement, the melt pond could become an even stronger sink for atmospheric CO2. Ice cores collected from the bottom of the melt pond were porous at the top 0.50 m, and contain large quantities of organic material similar to that identified floating in the water column This accumulation of material and ongoing degradation processes over the pond bottom ice would contribute significantly to the turnover of carbon, sulphur and nitrogen containing gases cycles within melt pond water and thereby gas exchange process with the atmosphere.MOSAi

Abiotic and biotic sources influencing spring new particle formation in North East Greenland

9 pages, 4 figuresIn order to improve our ability to predict cloud properties, radiative balance and climate, it is crucial to understand the mechanisms that trigger the formation of new particles and their growth to activation sizes. Using an array of real time aerosol measurements, we report a categorization of the aerosol population taken at Villum Research Station, Station Nord (VRS) in North Greenland during a period of 88 days (February–May 2015). A number of New Particle Formation (NPF) events were detected and are herein discussed. Air mass back trajectories analysis plotted over snow-sea ice satellite maps allowed us to correlate early spring (April) NPF events with air masses travelling mainly over snow on land and sea ice, whereas late spring (May) NPF events were associated with air masses that have passed mainly over sea ice regions. Concomitant aerosol mass spectrometry analysis suggests methanesulfonic acid (MSA) and molecular iodine (I) may be involved in the NPF mechanisms. The source of MSA was attributed to open leads within the sea ice. By contrast, iodine was associated with air masses over snow on land and over sea ice, suggesting both abiotic and biotic sources. Measurements of nucleating particle composition as well as gas-phase species are needed to improve our understanding of the links between emissions, aerosols, cloud and climate in the Arctic; therefore our ability to model such processesThe study was supported by the Spanish Ministry of Economy through project BIONUC (CGL 2013-49020-R), PIICE (CTM 2017-89117-R) and the Ramon y Cajal fellowship (RYC-2012-11922). The National Centre for Atmospheric ScienceNCAS Birmingham group is funded by the UK Natural Environment Research Council. [...]. This work was financially supported by the Danish Environmental Protection Agency with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region, which is part of the Danish contribution to “Arctic Monitoring and Assessment Program” (AMAP) and to the Danish research project “Short lived Climate Forcers” (SLCF), and the Danish Council for Independent Research (project NUMEN, DFF-FTP-4005-00485B). [...] This work was also supported by the Nordic Centre of Excellence (NCoE) Cryosphere-Atmosphere Interactions in a Changing Arctic Climate (CRAICC). The Villum Foundation is acknowledged for funding the construction of Villum Research Station, Station NordPeer Reviewe

Epigenetics in the primary and secondary prevention of cardiovascular disease: influence of exercise and nutrition

Increasing evidence links changes in epigenetic systems, such as DNA methylation, histone modification, and non-coding RNA expression, to the occurrence of cardiovascular disease (CVD). These epigenetic modifications can change genetic function under influence of exogenous stimuli and can be transferred to next generations, providing a potential mechanism for inheritance of behavioural intervention effects. The benefits of exercise and nutritional interventions in the primary and secondary prevention of CVD are well established, but the mechanisms are not completely understood. In this review, we describe the acute and chronic epigenetic effects of physical activity and dietary changes. We propose exercise and nutrition as potential triggers of epigenetic signals, promoting the reshaping of transcriptional programmes with effects on CVD phenotypes. Finally, we highlight recent developments in epigenetic therapeutics with implications for primary and secondary CVD prevention

Translational opportunities of single-cell biology in atherosclerosis

The advent of single-cell biology opens a new chapter for understanding human biological processes and for diagnosing, monitoring, and treating disease. This revolution now reaches the field of cardiovascular disease (CVD). New technologies to interrogate CVD samples at single-cell resolution are allowing the identification of novel cell communities that are important in shaping disease development and direct towards new therapeutic strategies. These approaches have begun to revolutionize atherosclerosis pathology and redraw our understanding of disease development. This review discusses the state-of-the-art of single-cell analysis of atherosclerotic plaques, with a particular focus on human lesions, and presents the current resolution of cellular subpopulations and their heterogeneity and plasticity in relation to clinically relevant features. Opportunities and pitfalls of current technologies as well as the clinical impact of single-cell technologies in CVD patient care are highlighted, advocating for multidisciplinary and international collaborative efforts to join the cellular dots of CVD