Rearrangement of Cyclotriveratrylene (CTV) Diketone: 9,10-Diarylanthracenes with OLED Applications

Electroluminescent 9,10-diaryl anthracenes have been shown to be promising host and hole-transporting materials in organic electroluminescence due to their high thermal stability, electrochemical reversibility, and wide band gap useful for organic light-emitting diodes (OLEDs), especially blue OLEDs. Oxidation of cyclotriveratrylene (CTV) to the corresponding diketone and subsequent bromination resulted in an unexpected rearrangement to a highly functionalized 9-aryl-10-bromoanthracene derivative, which was employed in Suzuki couplings to synthesize a series of 9,10-diaryl compounds that are structural analogues of anthracene derivatives used in the preparation of OLEDs but are more highly functionalized, including electron-donating methoxy groups in addition to substitution by a carboxylic acid moiety. The UV/fluorescence solution spectra show strong emissions at 446, 438, and 479 nm, respectively, for the anthracene 10-phenyl, 10-naphthyl, and 10-pyrenyl adducts containing a benzoic acid functional group, whereas the analogues bearing the hydroxymethylene moiety from reduction of the benzoic acid to the corresponding alcohols gave much shorter emission wavelengths of 408, 417, and 476 nm, respectively, and had somewhat higher quantum yields, suggesting they are better candidates for OLED applications

Modular differential equations for torus one-point functions

It is shown that in a rational conformal field theory every torus one-point function of a given highest weight state satisfies a modular differential equation. We derive and solve these differential equations explicitly for some Virasoro minimal models. In general, however, the resulting amplitudes do not seem to be expressible in terms of standard transcendental functions.Comment: 19 pages, LaTeX; reference adde

Problematic use of the Internet is a unidimensional quasi-trait with impulsive and compulsive subtypes

Abstract: Background: Problematic use of the Internet has been highlighted as needing further study by international bodies, including the European Union and American Psychiatric Association. Knowledge regarding the optimal classification of problematic use of the Internet, subtypes, and associations with clinical disorders has been hindered by reliance on measurement instruments characterized by limited psychometric properties and external validation. Methods: Non-treatment seeking individuals were recruited from the community of Stellenbosch, South Africa (N = 1661), and Chicago, United States of America (N = 827). Participants completed an online version of the Internet Addiction Test, a widely used measure of problematic use of the Internet consisting of 20-items, measured on a 5-point Likert-scale. The online questions also included demographic measures, time spent engaging in different online activities, and clinical scales. The psychometric properties of the Internet Addiction Test, and potential problematic use of the Internet subtypes, were characterized using factor analysis and latent class analysis. Results: Internet Addiction Test data were optimally conceptualized as unidimensional. Latent class analysis identified two groups: those essentially free from Internet use problems, and those with problematic use of the Internet situated along a unidimensional spectrum. Internet Addiction Test scores clearly differentiated these groups, but with different optimal cut-offs at each site. In the larger Stellenbosch dataset, there was evidence for two subtypes of problematic use of the Internet that differed in severity: a lower severity “impulsive” subtype (linked with attention-deficit hyperactivity disorder), and a higher severity “compulsive” subtype (linked with obsessive-compulsive personality traits). Conclusions: Problematic use of the Internet as measured by the Internet Addiction Test reflects a quasi-trait - a unipolar dimension in which most variance is restricted to a subset of people with problems regulating Internet use. There was no evidence for subtypes based on the type of online activities engaged in, which increased similarly with overall severity of Internet use problems. Measures of comorbid psychiatric symptoms, along with impulsivity, and compulsivity, appear valuable for differentiating clinical subtypes and could be included in the development of new instruments for assessing the presence and severity of Internet use problems

A novel ChREBP isoform in adipose tissue regulates systemic glucose metabolism

The prevalence of obesity and type 2-diabetes is increasing worldwide and threatens to shorten lifespan. Impaired insulin action in peripheral tissues is a major pathogenic factor. Insulin stimulates glucose uptake in adipose tissue through the Glut4-glucose transporter and alterations in adipose-Glut4 expression or function regulate systemic insulin sensitivity. Downregulation of adipose tissue-Glut4 occurs early in diabetes development. Here we report that adipose tissue-Glut4 regulates the expression of carbohydrate responsive-element binding protein (ChREBP), a transcriptional regulator of lipogenic and glycolytic genes. Furthermore, adipose-ChREBP is a major determinant of adipose tissue fatty acid synthesis and systemic insulin sensitivity. We discovered a new mechanism for glucose-regulation of ChREBP: Glucose-mediated activation of the canonical ChREBP isoform (ChREBPα) induces expression of a novel, potent isoform (ChREBPβ) that is transcribed from an alternative promoter. ChREBPβ expression in human adipose tissue predicts insulin sensitivity indicating that it may be an effective target for treating diabetes

Problematic internet use (PIU): Associations with the impulsive-compulsive spectrum. An application of machine learning in psychiatry.

Problematic internet use is common, functionally impairing, and in need of further study. Its relationship with obsessive-compulsive and impulsive disorders is unclear. Our objective was to evaluate whether problematic internet use can be predicted from recognised forms of impulsive and compulsive traits and symptomatology. We recruited volunteers aged 18 and older using media advertisements at two sites (Chicago USA, and Stellenbosch, South Africa) to complete an extensive online survey. State-of-the-art out-of-sample evaluation of machine learning predictive models was used, which included Logistic Regression, Random Forests and Naïve Bayes. Problematic internet use was identified using the Internet Addiction Test (IAT). 2006 complete cases were analysed, of whom 181 (9.0%) had moderate/severe problematic internet use. Using Logistic Regression and Naïve Bayes we produced a classification prediction with a receiver operating characteristic area under the curve (ROC-AUC) of 0.83 (SD 0.03) whereas using a Random Forests algorithm the prediction ROC-AUC was 0.84 (SD 0.03) [all three models superior to baseline models p < 0.0001]. The models showed robust transfer between the study sites in all validation sets [p < 0.0001]. Prediction of problematic internet use was possible using specific measures of impulsivity and compulsivity in a population of volunteers. Moreover, this study offers proof-of-concept in support of using machine learning in psychiatry to demonstrate replicability of results across geographically and culturally distinct settings.This research received internal departmental funds of the Department of Psychiatry at the University of Chicago.This is the final version of the article. It first appeared from Elsevier at http://dx.doi.org/10.1016/j.jpsychires.2016.08.010

Quantum critical fluctuations in an Fe-based superconductor

Quantum critical fluctuations may prove to play an instrumental role in the formation of unconventional superconductivity. Here, we show that the characteristic scaling of a marginal Fermi liquid is present in inelastic light scattering data of an Fe-based superconductor tuned through a quantum critical point (QCP) by chemical substitution or doping. From the doping dependence of the imaginary time dynamics we are able to distinguish regions dominated by quantum critical behavior from those having classical critical responses. This dichotomy reveals a connection between the marginal Fermi liquid behavior and quantum criticality. In particular, the overlap between regions of high superconducting transition temperatures and quantum critical scaling suggests a contribution from quantum fluctuations to the formation of superconductivity

Quantum critical fluctuations in an Fe-based superconductor

Quantum critical fluctuations may prove to play an instrumental role in the formation of unconventional superconductivity. Here, we show that the characteristic scaling of a marginal Fermi liquid is present in inelastic light scattering data of an Fe-based superconductor tuned through a quantum critical point (QCP) by chemical substitution or doping. From the doping dependence of the imaginary time dynamics we are able to distinguish regions dominated by quantum critical behavior from those having classical critical responses. This dichotomy reveals a connection between the marginal Fermi liquid behavior and quantum criticality. In particular, the overlap between regions of high superconducting transition temperatures and quantum critical scaling suggests a contribution from quantum fluctuations to the formation of superconductivity

Synthesis, Crystal Structure, and Rearrangements of ortho-Cyclophane Cyclotetraveratrylene (CTTV) tetraketone

Oxidation of cyclotetraveratrylene (CTTV) with potassium permanganate in pyridine under reflux gave tetraketone (the [14]ketonand) 3 which exists as a previously unobserved barrel conformation with S4symmetry in the crystal structure, although the more familiar ‘boat’ conformer was shown by semi-empirical AM1 calculations to be 3.03 kcal/mol lower in energy. In addition to CTTV tetraketone 3, an isomeric bis-spirolactone 4 was isolated from the basic oxidation conditions, analogous to the product of trans-annular attack and rearrangement observed with oxidation of cyclotriveratrylene, whereas in acid at elevated temperatures, tetraketone 3 underwent a very efficient rearrangement and decarboxylation to afford the highly symmetric spirobi[anthracene]-10,10′-dione derivative 5