Symptoms of Orthorexia Nervosa are associated with time spent on social media: a web-based survey in an Italian population sample.

OBJECTIVE: Orthorexia Nervosa (ON) is an eating disorder of growing interest that is characterized by an obsession with healthy eating. Nowadays, people spend an increasing amount of time on social media, which may negatively impact eating behaviors. The aim of this study was to investigate the relationship between social media usage and risk of ON. SUBJECTS AND METHODS: We conducted an online survey using the 10-item Italian-Düsseldorf Orthorexia Scale questionnaire (I-DOS). A total of 4,107 individuals participated and were classified according to sex, age, education level, marital status, BMI, main occupation, and diet. RESULTS: The prevalence of ON was 28.5%. Participants who reported using social media for over 60 minutes per day had a higher prevalence of ON than those using social media for less than 15 minutes per day. CONCLUSIONS: The results of this study suggest that longer time spent on social media is associated with ON.

Doped nematic phases: a tool for amplifying and detecting chirality.

Doping nematic liquid crystals with non-racemic chiral compounds induces twisted nematics (cholesteric phases). This phenomenon allows the detection via spectroscopic or non-spectroscopic methods of chiral compounds through the detection (and eventually quantification) of the macroscopic induced cholesteric twist.

Supramolecular detection of metal ion binding: ligand conformational control of cholesteric induction in nematic liquid crystalline phases.

Tripodal tetradentate ligands may act as chemosensor molecules. Their ability to torque a nematic into a cholesteric phase increases upon complexation with copper ion. Moreover, changes in overall shape of the complexes induced by different metals and counter ions were transferred sensitively to the supramolecular level, observed by proportionate changes in the degree of twisting. Modification of the oxidation state of the metal center also gave large changes in twisting power; this suggests potential application in electrochemical molecular switches. The handedness of the induced cholesteric phase is related to the stereochemistry of the ligand: The small amount of chiral dopant needed for the LC technique (less than 2 nmol) suggests the possible determination of the absolute configuration of the parent primary amines of the ligands.

The chirality of the cholesteric phases of DNA and G-wires: its connection to their molecular structures.

While the handedness of the cholesteric phases formed by assembled guanosine derivatives (G-wires) follow the correlation right-handed helices-->right-handed cholesterics (left-handed -->left-handed), the cholesteric phase formed by B-DNA (right-handed helix) is left-handed. This apparent discrepancy is overcome by considering pitch (p) variations with temperature. Plots of p(-1) versus T(-1) have, in fact, the same trend (positive intercept and negative slope) in the case of right-handed G-wires and B-DNA, while for the left-handed G-wire of deoxyguanosine monophosphate (dGMP), the opposite behavior is observed (negative intercept and positive slope). Therefore, the relation between molecular handedness and cholesteric helicity cannot, in general, be assessed by using measurements based on a single temperature; hence the temperature variation of the cholesteric parameters should be investigated. In all cases there is no remarkable salt effect on the cholesteric parameters.

Conformational analysis in solution of C(2)-symmetric 1, 1'-binaphthyl derivatives by circular dichroism spectroscopy and cholesteric induction in nematic mesophases

The twisting ability of a series of 1,1'-binaphthalene compounds used as dopants in nematic solvents has been related to the dihedral angle theta between the two naphthalene moieties. While in the case of the more flexible compounds the sign and value of the helical twisting power is affected by several structural features that prevent a simple assignment of the conformation, in the presence of a covalent bridge that restricts the rotation around the C(1)-C(1') bond a reliable estimate of the conformational helicity could be obtained. This technique is complementary to CD spectroscopy that, for the investigated molecules, presents the same exciton patterns irrespective of the actual theta value.