New family of graphene-based organic semiconductors: An investigation of photon-induced electronic structure manipulation in half-fluorinated graphene

The application of graphene to electronic and optoelectronic devices is limited by the absence of reliable semiconducting variants of this material. A promising candidate in this respect is graphene oxide, with a band gap on the order of ∼5eV, however, this has a finite density of states at the Fermi level. Here, we examine the electronic structure of three variants of half -fluorinated carbon on Sic(0001), i.e., the (6√3×6√3) R30° C/SiC "buffer layer," graphene on this (6√3×6√3) R30° C/SiC buffer layer, and graphene decoupled from the SiC substrate by hydrogen intercalation. Using angle-resolved photoemission, core level photoemission, and x-ray absorption, we show that the electronic, chemical, and physical structure of all three variants is remarkably similar, exhibiting a large band gap and a vanishing density of states at the Fermi level. These results are explained in terms of first-principles calculations. This material thus appears very suitable for applications, even more so since it is prepared on a processing-friendly substrate. We also investigate two separate UV photon-induced modifications of the electronic structure that transform the insulating samples (6.2-eV band gap) into semiconducting (∼2.5-eV band gap) and metallic regions, respectively

Differential expansion of circulating human MDSC subsets in patients with cancer, infection and inflammation

Background Myeloid-derived suppressor cells (MDSC) are a functional myeloid cell subset that includes myeloid cells with immune suppressive properties. The presence of MDSC has been reported in the peripheral blood of patients with several malignant and non-malignant diseases. So far, direct comparison of MDSC across different diseases and Centers is hindered by technical pitfalls and a lack of standardized methodology. To overcome this issue, we formed a network through the COST Action Mye-EUNITER (www.mye-euniter.eu) with the goal to standardize and facilitate the comparative analysis of human circulating MDSC in cancer, inflammation and infection. In this manuscript, we present the results of the multicenter study Mye-EUNITER MDSC Monitoring Initiative, that involved 13 laboratories and compared circulating MDSC subsets across multiple diseases, using a common protocol for the isolation, identification and characterization of these cells. Methods We developed, tested, executed and optimized a standard operating procedure for the isolation and immunophenotyping of MDSC using blood from healthy donors. We applied this procedure to the blood of almost 400 patients and controls with different solid tumors and non-malignant diseases. The latter included viral infections such as HIV and hepatitis B virus, but also psoriasis and cardiovascular disorders. Results We observed that the frequency of MDSC in healthy donors varied substantially between centers and was influenced by technical aspects such as the anticoagulant and separation method used. Expansion of polymorphonuclear (PMN)-MDSC exceeded the expansion of monocytic MDSC (M-MDSC) in five out of six solid tumors. PMN-MDSC expansion was more pronounced in cancer compared with infection and inflammation. Programmed death-ligand 1 was primarily expressed in M-MDSC and e-MDSC and was not upregulated as a consequence of disease. LOX-1 expression was confined to PMN-MDSC. Conclusions This study provides improved technical protocols and workflows for the multi-center analysis of circulating human MDSC subsets. Application of these workflows revealed a predominant expansion of PMN-MDSC in solid tumors that exceeds expansion in chronic infection and inflammation

Problematic online behaviors among adolescents and emerging adults: associations between cyberbullying perpetration, problematic social media use, and psychosocial factors

Over the past two decades, young people's engagement in online activities has grown markedly. The aim of the present study was to examine the relationship between two specific online behaviors (i.e., cyberbullying perpetration, problematic social media use) and their relationships with social connectedness, belongingness, depression, and self-esteem among high school and university students. Data were collected from two different study groups via two questionnaires that included the Cyberbullying Offending Scale, Social Media Use Questionnaire, Social Connectedness Scale, General Belongingness Scale, Short Depression-Happiness Scale, and Single Item Self-Esteem Scale. Study 1 comprised 804 high school students (48% female; mean age 16.20 years). Study 2 comprised 760 university students (60% female; mean age 21.48 years). Results indicated that problematic social media use and cyberbullying perpetration (which was stronger among high school students) were directly associated with each other. Belongingness (directly) and social connectedness (indirectly) were both associated with cyberbullying perpetration and problematic social media use. Path analysis demonstrated that while age was a significant direct predictor of problematic social media use and cyberbullying perpetration among university students, it was not significant among high school students. In both samples, depression was a direct predictor of problematic social media use and an indirect predictor of cyberbullying perpetration. However, majority of these associations were relatively weak. The present study significantly adds to the emerging body of literature concerning the associations between problematic social media use and cyberbullying perpetration

The mediating role of self/everyday creativity and depression on the relationship between creative personality traits and problematic social media use among emerging adults

Personality is one of the important contributory factors in the development of problematic technology use. The purpose of the present study was to investigate the direct and indirect associations of creative personality traits with problematic social media use via self/everyday creativity, depression, and loneliness. A total of 460 Turkish emerging adults aged between 18 and 26 years (61% female) were surveyed. Findings indicated that (i) task-orientedness was indirectly associated with problematic social media use via self/everyday creativity, (ii) self-confidence was directly and indirectly associated with problematic social media use via self/everyday creativity and depression, (iii) risk-taking was indirectly associated with problematic social media use via depression, and (iv) self/everyday creativity and depression were directly associated with problematic social media use. The present study is the first to suggest that creative personality traits (i.e., task-orientedness, self-confidence, and risk-taking) and self/everyday creativity are associated with problematic social media use and that these factors should be taken into account when considering the etiology of problematic social media use

Development and validation of Videogame Addiction Scale for Children (VASC)

The aim of the present study was to develop a valid and reliable Videogame Addiction Scale for Children (VASC). The data were derived from 780 children who completed the Videogame Addiction Scale (405 girls and 375 boys; 48.1% ranging in age from 9 to 12 years). The sample was randomly split into two different sub-samples (sample 1, n=400; sample 2, n= 380). Sample 1 was used to perform exploratory factor analysis (EFA) to define the factorial structure of VASC. As a result of EFA, a four-factor structure comprising 21 items was obtained and explained 55% of the total variance (the four factors being "self-control," "reward/reinforcement", "problems," and "involvement"). The internal consistency reliability of VASC has found 0.89. Confirmatory factor analysis (CFA) was performed to confirm the factorial structure obtained by EFA in the remaining half of sample (n= 390). The obtained fit indices from the CFA confirmed the structure of the EFA. The 21-item VASC has good psychometric properties that can be used among Turkish schoolchildren populations

Trait emotional intelligence and problematic social media use among adults: the mediating role of social media use motives

There are many contributing factors to problematic social media use including personality differences, psychosocial factors, and specific use motivations. The present study (N = 444 emerging adults, 75% women) investigated the direct and indirect relationships between trait emotional intelligence and problematic social media use via social media use motives by testing a complex mediation model. Path analyses suggested that trait emotional intelligence was directly and indirectly associated with problematic social media use via two social media use motives: (i) expressing or presenting a more popular self, and (ii) passing time. Results of the present study indicate that trait emotional intelligence may have a role in the motives for using social media as well as the development and maintenance of problematic social media use. Moreover, future studies should focus mediator risk factors between trait emotional intelligence and problematic social media use

Is problematic mobile phone use explained by chronotype and personality?

PMID = 2712881