Molecular diffusion and self-assembly: Quantifying the influence of substrate hcp and fcc atomic stacking

Molecular diffusion is a fundamental process underpinning surface-confined molecular self-assembly and synthesis. Substrate topography influences molecular assembly, alignment, and reactions; with the relationship between topography and diffusion linked to the thermodynamic evolution of such processes. Here, we observe preferential adsorption sites for tetraphenylpor-phyrin (2H-TPP) on Au(111) and interpret nucleation and growth of molecular islands at these sites in terms of spatial variation in diffusion barrier; driven by local atomic arrangements of the Au(111) surface (the 22× √ 3 'herringbone' reconstruction). Variable-temperature scanning tunnelling microscopy facilitates characterisation of molecular diffusion, and Arrhenius analysis allows quantitative characterisation of diffusion barriers within fcc and hcp regions of the surface reconstruction (where the in-plane arrangement of the surface atoms is identical, but the vertical stacking differs). The higher barrier for diffusion within fcc locations underpins the ubiquitous observation of preferential island growth within fcc regions, demonstrating the relationship between substrate-structure, diffusion, and molecular self-assembly

Association of acute coronary syndrome-induced posttraumatic stress disorder symptoms with self-reported sleep

Background Symptoms of posttraumatic stress disorder (PTSD) after acute coronary syndrome (ACS) are associated with recurrent ACS events and mortality. Poor sleep may be a mechanism, but the association between PTSD and sleep after ACS is unknown. Purpose This study aims to estimate the association between ACS-induced PTSD symptoms and self-reported sleep. Methods ACS-induced PTSD symptoms were assessed 1-month post-ACS in 188 adults using the Impact of Events Scale-Revised. Sleep was assessed using the Pittsburgh Sleep Quality Index. Linear and logistic regression models were used to determine whether PTSD symptoms were associated with self-reported sleep, independent of sociodemographic and clinical covariates. Results In adjusted models, ACS-induced PTSD symptoms were associated with worse overall sleep (β = 0.22, p = 0.003) and greater impairment in six of seven components of sleep (all p values <0.05). Conclusions ACS-induced PTSD symptoms may be associated with poor sleep, which may explain why PTSD confers increased cardiovascular risk after ACS

Posttraumatic stress disorder and risk for coronary heart disease: A meta-analytic review

Objective The aim of this study was to estimate the association of posttraumatic stress disorder (PTSD) with risk for incident coronary heart disease (CHD). Design A systematic review and meta-analysis were used as study designs. Data Sources Articles were identified by searching Ovid MEDLINE, PsycINFO, Scopus, Cochrane Library, PILOTS database, and PubMed Related Articles and through a manual search of reference lists (1948-present). Study Selection All studies that assessed PTSD in participants initially free of CHD and subsequently assessed CHD/cardiac-specific mortality were included. Data Extraction Two investigators independently extracted estimates of the association of PTSD with CHD, as well as study characteristics. Odds ratios were converted to hazard ratios (HRs), and a random-effects model was used to pool results. A secondary analysis including only studies that reported estimates adjusted for depression was conducted. Results Six studies met our inclusion criteria (N = 402,274); 5 of these included depression as a covariate. The pooled HR for the magnitude of the relationship between PTSD and CHD was 1.55 (95% CI 1.34-1.79) before adjustment for depression. The pooled HR estimate for the 5 depression-adjusted estimates (N = 362,950) was 1.27 (95% CI 1.08-1.49). Conclusion Posttraumatic stress disorder is independently associated with increased risk for incident CHD, even after adjusting for depression and other covariates. It is common in both military veterans and civilian trauma survivors, and these results suggest that it may be a modifiable risk factor for CHD. Future research should identify the mechanisms of this association and determine whether PTSD treatment offsets CHD risk

Microbial Assemblages in Association with Crayfish Ectosymbionts

Undergraduate Basi

NUMERICAL SIMULATION AND THERMOMETRIC MEASUREMENTS ON MOLD FILLING DYNAMICS

ABSTRACT In this paper we present the results of the CFD simulations of the mold filling dynamics in gravity and counter-gravity lost foam castings. FLOW-3D software package (Flow-Simulations, Inc.) has been used to predict flow velocity distributions and pressure losses when liquid metal flows in the step pattern. The results of simulations are compared to those obtained experimentally

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

Additive manufacturing or ‘3D printing’ is being developed as a novel manufacturing process for the production of bespoke micro- and milliscale fluidic devices. When coupled with online monitoring and optimisation software, this offers an advanced, customised method for performing automated chemical synthesis. This paper reports the use of two additive manufacturing processes, stereolithography and selective laser melting, to create multifunctional fluidic devices with embedded reaction monitoring capability. The selectively laser melted parts are the first published examples of multifunctional 3D printed metal fluidic devices. These devices allow high temperature and pressure chemistry to be performed in solvent systems destructive to the majority of devices manufactured via stereolithography, polymer jetting and fused deposition modelling processes previously utilised for this application. These devices were integrated with commercially available flow chemistry, chromatographic and spectroscopic analysis equipment, allowing automated online and inline optimisation of the reaction medium. This set-up allowed the optimisation of two reactions, a ketone functional group interconversion and a fused polycyclic heterocycle formation, via spectroscopic and chromatographic analysis

The ‘Perfect Storm’ and Acute Coronary Syndrome Onset: Do Psychosocial Factors Play a Role?

The revolution in cardiac care over the past two decades, characterized by emergent revascularization, drug eluting stents, anti-platelet medications, and advanced imaging has had little impact on overall ACS recurrence, or ACS prevention. The “Perfect Storm” refers to a confluence of events and processes, including atherosclerotic plaque, coronary flow dynamics, hemostatic and fibrinolytic function, metabolic and inflammatory conditions, neurohormonal dysregulation, and environmental events that give rise to, and result in an ACS event. In this article we illustrate the limits of the traditional main effect research model, giving a brief description of the current state of knowledge regarding the development of atherosclerotic plaque and the rupturing of these plaques that defines an ACS event. We then apply the Perfect Storm conceptualization to describe a program of research concerning a psychosocial vulnerability factor that contributes to increased risk of recurrent ACS and early mortality, and that has defied our efforts to identify underlying pathophysiology and successfully mount efforts to fully mitigate this risk

Do different depression phenotypes have different risks for recurrent coronary heart disease?

Although research has consistently established that depression and elevated depressive symptoms are associated with an increased risk of coronary heart disease (CHD) recurrence and mortality, clinical trials have failed to show that conventional depression interventions offset this risk. As depression is a complex and heterogeneous syndrome, we believe that examining simpler, or intermediary, phenotypes rather than one complex phenotype may allow better identification of those at particular risk of CHD recurrence and mortality. This approach may further contribute to the development of specific depression treatments that would improve medical outcomes. Although there are many possible intermediary phenotypes (IPs), specifiers and dimensions of depression, we will focus on only two when considering the relation between depression and risk of CHD recurrence and mortality: Incident Depression and Anhedonic Depression. Future research on IPs of depression is needed to clarify which are associated with the greatest risk for CHD recurrence and mortality and which, if any, are benign. Theoretical advances in depression phenotyping may also help elucidate the behavioural and biological mechanisms underlying the increased risk of CHD among patients with specific depression phenotypes. Finally, tests of depression interventions may be guided by this new theoretical approach