Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained

Genetic liability to major depression and risk of childhood asthma

OBJECTIVE: Major depression and asthma frequently co-occur, suggesting shared genetic vulnerability between these two disorders. We aimed to determine whether a higher genetic liability for major depression was associated with increased childhood asthma risk, and if so, whether such an association differed by sex of the child. METHODS: We conducted a population-based cohort study comprising 16,687 singletons born between 1991 and 2005 in Denmark. We calculated the polygenic risk score (PRS) for major depression as a measure of genetic liability based on the summary statistics from the Major Depressive Disorder Psychiatric Genomics Consortium collaboration. The outcome was incident asthma from age 5 to 15 years, identified from the Danish National Patient Registry and the Danish National Prescription Registry. Stratified Cox regression was used to analyze the data. RESULTS: Greater genetic liability for major depression was associated with an increased asthma risk with a hazard ratio (HR) of 1.06 (95% CI: 1.01–1.10) per standard deviation increase in PRS. Children in the highest major depression PRS quartile had a HR for asthma of 1.20 (95% CI: 1.06–1.36), compared with children in the lowest quartile. However, major depression PRS explained only 0.03% of asthma variance (Pseudo-R(2)). The HRs of asthma by major depression PRS did not differ between boys and girls. CONCLUSION: Our results suggest a shared genetic contribution to major depression and childhood asthma, and there is no evidence of a sex-specific difference in the association

Genome-wide by Environment Interaction Study of Stressful Life Events and Hospital-Treated Depression in the iPSYCH2012 Sample

BACKGROUND: Researchers have long investigated a hypothesized interaction between genetic risk and stressful life events in the etiology of depression, but studies on the topic have yielded inconsistent results. METHODS: We conducted a genome-wide by environment interaction study (GWEIS) in 18,532 patients with depression from hospital-based settings and 20,184 population controls. All individuals were drawn from the iPSYCH2012 case-cohort study, a nationally representative sample identified from Danish national registers. Information on stressful life events including family disruption, serious medical illness, death of a first-degree relative, parental disability, and child maltreatment was identified from the registers and operationalized as a time-varying count variable. Hazard ratios for main and interaction effects were estimated using Cox regressions weighted to accommodate the case-cohort design. Our replication sample included 22,880 depression cases and 50,378 controls from the UK Biobank. RESULTS: The GWEIS in the iPSYCH2012 sample yielded three novel, genome-wide–significant (p < 5 × 10(−8)) loci located in the ABCC1 gene (rs56076205, p = 3.7 × 10(−10)), the AKAP6 gene (rs3784187, p = 1.2 × 10(−8)), and near the MFSD1 gene (rs340315, p = 4.5 × 10(−8)). No hits replicated in the UK Biobank (rs56076205: p = .87; rs3784187: p = .93; rs340315: p = .71). CONCLUSIONS: In this large, population-based GWEIS, we did not find any replicable hits for interaction. Future gene-by-stress research in depression should focus on establishing even larger collaborative GWEISs to attain sufficient power

Genome-wide by Environment Interaction Study of Stressful Life Events and Hospital-Treated Depression in the iPSYCH2012 Sample

BackgroundResearchers have long investigated a hypothesized interaction between genetic risk and stressful life events in the etiology of depression, but studies on the topic have yielded inconsistent results.MethodsWe conducted a genome-wide by environment interaction study (GWEIS) in 18,532 patients with depression from hospital-based settings and 20,184 population controls. All individuals were drawn from the iPSYCH2012 case-cohort study, a nationally representative sample identified from Danish national registers. Information on stressful life events including family disruption, serious medical illness, death of a first-degree relative, parental disability, and child maltreatment was identified from the registers and operationalized as a time-varying count variable. Hazard ratios for main and interaction effects were estimated using Cox regressions weighted to accommodate the case-cohort design. Our replication sample included 22,880 depression cases and 50,378 controls from the UK Biobank.ResultsThe GWEIS in the iPSYCH2012 sample yielded three novel, genome-wide-significant (p &lt; 5&nbsp;× 10-8) loci located in the ABCC1 gene (rs56076205, p&nbsp;= 3.7&nbsp;× 10-10), the AKAP6 gene (rs3784187, p&nbsp;= 1.2&nbsp;× 10-8), and near the MFSD1 gene (rs340315, p&nbsp;= 4.5&nbsp;× 10-8). No hits replicated in the UK Biobank (rs56076205: p&nbsp;= .87; rs3784187: p&nbsp;= .93; rs340315: p&nbsp;= .71).ConclusionsIn this large, population-based GWEIS, we did not find any replicable hits for interaction. Future gene-by-stress research in depression should focus on establishing even larger collaborative GWEISs to attain sufficient power