Time-resolved formation of excited atomic and molecular states in XUV-induced nanoplasmas in ammonia clusters

High intensity XUV radiation from a free-electron laser (FEL) was used to create a nanoplasma inside ammonia clusters with the intent of studying the resulting electron-ion interactions and their interplay with plasma evolution. In a plasma-like state, electrons with kinetic energy lower than the local collective Coulomb potential of the positive ionic core are trapped in the cluster and take part in secondary processes (e.g. electron-impact excitation/ionization and electron-ion recombination) which lead to subsequent excited and neutral molecular fragmentation. Using a time-delayed UV laser, the dynamics of the excited atomic and molecular states are probed from -0.1 ps to 18 ps. We identify three different phases of molecular fragmentation that are clearly distinguished by the effect of the probe laser on the ionic and electronic yield. We propose a simple model to rationalize our data and further identify two separate channels leading to the formation of excited hydrogen.

Concordance between health administrative data and survey-derived diagnoses for mood and anxiety disorders

OBJECTIVE

To assess whether estimates of survey structured interview diagnoses of mood and anxiety disorders were concordant with diagnoses of these disorders obtained from health administrative data.

METHODS

All Ontario respondents to the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH) were linked to health administrative databases at ICES (formerly known as the Institute for Clinical Evaluative Sciences). Survey structured interview diagnoses were compared with health administrative data diagnoses obtained using a standardized algorithm. We used modified Poisson regression analyses to assess whether socio-demographic factors were associated with concordance between the two measures.

RESULTS

Of the 4157 Ontarians included in our sample, 20.4% had either a structured interview diagnosis (13.9%) or health administrative diagnosis (10.4%) of a mood or anxiety disorder. There was high discordance between measures, with only 19.4% agreement. Migrant status, age, employment, and income were associated with discordance between measures.

CONCLUSIONS

Our findings indicate that previous estimates of the 12-month prevalence of mood and anxiety disorders in Ontario may be underestimating the true prevalence, and that population-based surveys and health administrative data may be capturing different groups of people. Understanding the limitations of data commonly used in epidemiologic studies is a key foundation for improving population-based estimates of mental disorders.

Relationship between sleep patterns and multimorbidity in the Canadian Longitudinal Study on Aging

Background

Sleep difficulties are an unmet public health problem, affecting large segments of the population around the world. Poor sleep quality and reduced sleep duration impact over half of older adults and are associated with adverse health outcomes like multiple chronic diseases (multimorbidity) and reduced longevity.

Methods

A cross-sectional analysis of the Canadian Longitudinal Study on Aging (CLSA), a national health survey of community-dwelling adults and older adults. A total of 30,011 participants had physiological and psychosocial data collected at baseline. Sleep measures included self-reported sleep duration (short: <6 hours, normal: 6-8 hours, long: >8 hours) and sleep quality (dissatisfied/very dissatisfied, neutral, satisfied/very satisfied). To capture multimorbidity, a primary definition was operationalized with 17 chronic conditions, whereas a secondary definition was operationalized with 9 chronic conditions to capture both the primary care and public health perspective.

Results

In our sample, 50.9% were female (average age: 62.7 years) and 49.1% were male (average age: 63.2 years). The majority reported a normal sleep duration and approximately half reported being either satisfied or very satisfied with sleep quality. About 70% were living with multimorbidity using the primary care definition (females: 71.7%; males 64.3%), while about 30% were living with multimorbidity using the public health definition (females: 34.8%; males: 28.9%). The adjusted analyses indicated the odds of multimorbidity increased for those who reported short or long sleep duration, as well as dissatisfaction with sleep quality, across age groups and both females and males.

Conclusions

Disrupted sleep may be an additional behavioural risk factor for a number of chronic diseases, in the context of aging populations. It is necessary to understand the potential impact of sleep on the risk of multimorbidity, and this research will build knowledge in this important area.

Key messages

This research will utilize a national health survey to examine and report the characteristics of sleep quality and sleep duration among approximately 30,000 community-dwelling adults in Canada. This research will explore relationships between sleep duration, sleep quality and multimorbidity (controlling for confounding factors) among community-dwelling adults in Canada.

Multimorbidity and quality of life: longitudinal analysis of the European SHARE database

Key messages

First longitudinal study to address this research questions across wide range of European countries using SHARE. Study accounts for large number of confounding factors owing to the abundance of collected information.

Sleep and Mental Health Among Older Adults in the Canadian Longitudinal Study on Aging

Background

Global studies have demonstrated consistent associations between sleep problems and mental health and well-being in older adults, however Canadian data are lacking. We investigated associations between sleep quantity and quality with both mental illness symptoms and well-being among older adults in Canada.

Methods

We used cross-sectional baseline data from the Canadian Longitudinal Study on Aging, a national survey of 30,097 community-dwelling adults aged 45 years and older. Self-reported sleep measures included average past-week sleep duration (short [<6h], normal [6-8h], long [>8h]), and sleep quality (satisfied or dissatisfied vs neutral). Mental illness outcomes included depressive symptoms and psychological distress. Mental well-being outcomes included self-rated mental health and satisfaction with life. We used modified Poisson regression models with adjustment for sociodemographic, behavioural, and clinical factors, and stratification by sex and age to explore effect modification.

Results

In the unadjusted analysis, short and long sleep duration and sleep dissatisfaction were associated with higher mental illness symptoms and lower well-being across all outcomes. Sleep satisfaction was associated with a lower likelihood of mental illness symptoms and better well-being. Short sleep duration was associated with the largest effects on mental health outcomes. Self-rated mental health and depressive symptoms had the largest associations with sleep measures. Effects were larger in males and the 45 to 54 year age group.

Conclusions

Preliminary evidence suggests sleep duration and quality are associated with symptoms of depression, psychological distress, and poor mental well-being among older adults. We are unable to determine whether sleep problems are a cause or consequence of poor mental health. Nonetheless, sleep may be an important target for public health initiatives to improve mental health and well-being among older adults.

Key messages

Our findings contribute further evidence that sleep difficulties are associated with adverse health outcomes including higher mental illness symptoms and lower well-being among older adults. Sleep disturbances are an unmet public health problem, and may be an important target for public health initiatives to improve mental health and well-being among older adults.

Epidemiological and nutritional transition in low- and middle-income countries

Issue/problem

In the last decades, the number of deaths from non-communicable diseases in developing countries has risen to those observed in developed countries.

Description of the problem

Nutritional research in developing countries has primarily focused on under-nutrition, particularly among vulnerable population subgroups such as women and children. However, while economic growth has a significant social impact at population level, there is suggestive evidence of an ongoing nutritional transition leading to concurrent under- and over-nutrition in the population.

Results

The ongoing nutritional transition in these settings has been mostly linked to the rapid process of urbanisation and westernization. Data from several developing countries suggest that improvements in developmental indicators is accompanied by higher availability of highly processed poorly nutritious foods. Regarding socioeconomic factors, results demonstrated that better education and better living standards were associated with higher odds of overweight/obesity after adjusting for confounders, including urban vs. rural setting. This is likely a consequence of the ongoing nutritional and epidemiological transition occurring in these settings. In fact, developing countries have not yet reached the same phase of nutritional transition as an economically affluent country, and while high-calorie diets comprising fast-food are the more economically affordable option in the latter, such diets are still reserved for the more affluent individuals in some developing countries, where economic growth has only just begun to allow affluent individuals to afford fast-food.

Conclusions

Understanding the underlying ecological and socioeconomic roots of both extremes of the nutritional status is vital to design successful public health interventions.

Angular Distribution of Ion Products in the Double Photoionization of Propylene Oxide

A photoelectron-photoion-photoion coincidence technique, using an ion imaging detector and tunable synchrotron radiation in the 18.0–37.0 eV photon energy range, inducing the ejection of molecular valence electrons, has been applied to study the double ionization of the propylene oxide, a simple prototype chiral molecule. The experiment performed at the Elettra Synchrotron Facility (Trieste, Italy) allowed to determine angular distributions for ions produced by the two-body dissociation reactions following the Coulomb explosion of the intermediate (C₃H₆O)²⁺ molecular dication. The analysis of the coincidence spectra recorded at different photon energies was done in order to determine the dependence of the β anisotropy parameter on the photon energy for the investigated two-body fragmentation channels. In particular, the reaction leading to CH3+ + C₂H₃O⁺ appears to be characterized by an increase of β, from β ≈ 0.00 up to β = 0.59, as the photon energy increases from 29.7 to 37.0 eV, respectively. This new observation confirms that the dissociation channel producing CH3+ and C₂H₃O⁺ final ions can occur with two different microscopic mechanisms as already indicated by the bimodality obtained in the kinetic energy released (KER) distributions as a function of the photon energy in a recent study. Energetic considerations suggest that experimental data are compatible with the formation of two different stable isomers of C₂H₃O⁺: acetyl and oxiranyl cations. These new experimental data are inherently relevant and are mandatory information for further experimental and theoretical investigations involving oriented chiral molecules and linearly or circularly polarized radiation. This work is in progress in our laboratory.

P5308Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease: Cochrane systematic review and meta-analysis of randomised clinical trials

Background

Observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on cardiovascular disease (CVD) but the randomised controlled trial (RCT) evidence is limited.

Objective

To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD.

Methods

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, DARE, HTA, NHS EED and trial registers (September 2018). We selected RCTs in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). Both of the following key components were required for our definition of a Mediterranean-style diet: high monounsaturated/saturated fat ratio and a high intake of plant based foods, including fruits, vegetables, and legumes. The intervention could be dietary advice, provision of relevant foods or both. The comparison group received either no intervention, minimal intervention, usual care or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of 3 months or more.

Results

Overall, 30 RCTs (12,461 participants randomised) and 7 ongoing trials met our inclusion criteria, whereas 22 primary prevention trials and 6 secondary prevention trials were analysed. Low quality evidence shows little or no effect of the PREDIMED (7747 randomised) intervention (advice to follow a Mediterranean diet plus supplemental extra virgin olive oil or tree nuts) compared to a low fat diet on CVD mortality (HR 0.81 (95% CI 0.5, 1.32)) or total mortality (HR 1.0 (95% CI 0.81, 1.24)) over 4.8 years. There was however a reduction in the number of strokes with the PREDIMED intervention (HR 0.6 (95% CI 0.45, 0.8), moderate quality evidence). For secondary prevention, in the Lyon Diet Heart Study (605 CVD patients), there was moderate quality evidence of a reduction in CVD mortality (HR 0.35 (95% CI 0.15, 0.82)) and total mortality (HR 0.44 (95% CI 0.21, 0.92)) with the intervention, over 46 months. For CVD risk factors, in primary prevention trials, there was low quality evidence for a possible small reduction in total cholesterol (−0.16 mmol/L (95% CI −0.32, 0.00), and moderate quality evidence for a reduction in SBP (−2.99 mmHg (95% CI −3.45, −2.53)) and DBP (−2.0 mmHg (95% CI −2.29, −1.71)). In secondary prevention trials, there was moderate quality evidence of no effect of a Mediterranean-style diet on lipid levels and low or very low quality evidence for blood pressure.

Conclusions

Despite the relatively large number of studies included in this review, there is still some uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and CVD risk factors for both primary and secondary prevention. The ongoing studies may provide more certainty in the future.

Real-Time Dynamics of the Formation of Hydrated Electrons upon Irradiation of Water Clusters with Extreme Ultraviolet Light

Free electrons in a polar liquid can form a bound state via interaction with the molecular environment. This so-called hydrated electron state in water is of fundamental importance, e.g., in cellular biology or radiation chemistry. Hydrated electrons are highly reactive radicals that can either directly interact with DNA or enzymes, or form highly excited hydrogen (H^{*}) after being captured by protons. Here, we investigate the formation of the hydrated electron in real-time employing extreme ultraviolet femtosecond pulses from a free electron laser, in this way observing the initial steps of the hydration process. Using time-resolved photoelectron spectroscopy we find formation timescales in the low picosecond range and resolve the prominent dynamics of forming excited hydrogen states.

Double photoionization of propylene oxide: A coincidence study of the ejection of a pair of valence-shell electrons

Propylene oxide, a favorite target of experimental and theoretical studies of circular dichroism, was recently discovered in interstellar space, further amplifying the attention to its role in the current debate on protobiological homochirality. In the present work, a photoelectron-photoion-photoion coincidence technique, using an ion-imaging detector and tunable synchrotron radiation in the 18.0-37.0 eV energy range, permits us (i) to observe six double ionization fragmentation channels, their relative yields being accounted for about two-thirds by the couple (C₂H₄⁺, CH₂O⁺) and one-fifth by (C₂H₃⁺, CH₃O⁺); (ii) to measure thresholds for their openings as a function of photon energy; and (iii) to unravel a pronounced bimodality for a kinetic-energy-released distribution, fingerprint of competitive non-adiabatic mechanisms.

Subtraction of subcutaneous fat to improve the prediction of visceral adiposity: exploring a new anthropometric track in overweight and obese youth

BACKGROUND

The efficiency of traditional anthropometric measurements such as body mass index (BMI) or waist circumference (Waist C) used to replace biomedical imaging for assessing visceral adipose tissue (VAT) is still highly controversial in youth.

HYPOTHESIS AND OBJECTIVES

We evaluated the most accurate model predicting VAT in overweight/obese youth, using various anthropometric measurements and their correlation with different body fat compartments, especially by testing, for the first time in youth, the hypothesis that subtracting the anthropometric measurement the most highly correlated with subcutaneous abdominal adipose tissue (SAAT) and less correlated possible with VAT from an anthropometric abdominal measurement highly correlated with visceral and total abdominal adipose tissue (TAAT), predicts VAT with higher accuracy.

SUBJECTS AND METHODS

VAT and SAAT data resulted from magnetic resonance imaging (MRI) analysis performed on 181 boys and girls (7-17 y) from Diabetes & Endocrinology Care Paediatrics Clinic in Luxembourg. Height, weight, abdominal diameters, waist, hip, and thigh circumferences were measured with a view to developing the anthropometric VAT predictive algorithms.

RESULTS

In girls, subtracting proximal thigh circumference (Proximal Thigh C), the most closely correlated anthropometric measurement with SAAT, from Waist C, the most closely correlated anthropometric measurement with VAT was instrumental in improving VAT prediction, in comparison with the most accurate single VAT anthropometric surrogate. [Formula: see text] Residual analysis showed a negligible estimation error (5 cm² ). In boys, Waist C was the best VAT predictor.

CONCLUSIONS

Subtraction of abdominal subcutaneous fat is important to predict VAT in overweight/obese girls.

Single Photon Thermal Ionization of C_{60}

We report on experiments which show that C_{60} can ionize in an indirect, quasithermal boiloff process after absorption of a single photon. The process involves a large number of incoherently excited valence electrons and yields electron spectra with a Boltzmann distribution with temperatures exceeding 10^{4}  K. It is expected to be present for other molecules and clusters with a comparatively large number of valence electrons. The astrophysical consequences are briefly discussed.