To understand the relationship between kinetically controlled hierarchical superstructures and photophysical properties, pyrene-based asymmetric liquid crystal (LC) dendrons (abbreviated as PD) were newly synthesized by covalently attaching a pyrene moiety (P) at a biphenyl-based LC dendritic group (D). The phase transition behavior of PD has been systematically studied with a combined technique of thermal analysis, microscopy, spectroscopy, and scattering analysis. PD formed two different crystalline structures depending on the cooling rate: a stable crystalline phase (K , slow cooling) and a metastable crystalline phase (K , quenching). The kinetically controlled molecular packing structures of PD depend on the competition and cooperation of intermolecular physical interactions with nanophase separation. Upon slow cooling, the PD dimer formed by intermoelcular H-bonding constructed a layered hierarchical structure with the help of nanophase separation. Owing to the strong π-π stacking (J-aggregation) with weak H-bondings, the PD dimer in the layer was slightly tilted to give a monoclinic layered structure with a periodic layer d-spacing of 6.6 nm. In contrast, the metastable K phase formed by the quenching process showed a significant tilt of the PD dimer in the layer (d-spacing=4.4 nm) due to the weak π-π stacking (H-aggregation) and the strong H-bondings.

Figure 5. Secret barcodes deciphered by tuning temperature and transmission axis of the linear polarizer.

Household food insecurity has been associated with noncommunicable diseases. The aim of this study was to investigate the association between household food insecurity and asthma in Korean adults. Household food security statuses were classified into three groups: Food-secure household, food-insecure household without hunger, and food-insecure household with hunger. The odds ratios and 95% confidence intervals for the presence of asthma according to household food security status were calculated using multiple logistic regression analyses after adjusting for confounding factors. A total of 14,770 participants were included in the analysis. The prevalence of asthma was 2.6% in those with a secure food status, 3.2% in those with an insecure food status without hunger, and 7.6% in those with an insecure food status with hunger (p < 0.001). Compared with that in participants with a household food secure status, the odds ratios (95% confidence intervals) for asthma were 1.12 (0.73–1.73) in those with a food-insecure household without hunger status and 2.44 (1.33–4.46) in those with a food-insecure household with hunger status after additionally adjusting for confounding factors. We found that household food insecurity with hunger was significantly associated with asthma prevalence in Korean adults. Implementation of household food security screening and public health intervention could be helpful to prevent and reduce asthma in adults.

For flexible displays, there is a desperate need for a broadband coatable polarizer that can absorb light in a specific direction. Conventional polarizers fabricated by the polymer stretching process are too thick (50−200 μm) to be used as polarizers that can be applied to antireflective films in flexible displays. For the development of the broadband coatable thin film polarizer, diacetylene (DA) amphiphiles containing I − or I 3 − are newly designed and synthesized, and the content of DA amphiphiles in the 4,6-decadiyne solvent is optimized to form a lyotropic liquid crystal (LLC) phase. Topochemical polymerization of uniaxially oriented iodine-based DA not only stabilizes the film but also broadens the polarization light region from 350 to 700 nm. The transfer and amplification of iodine and DA functions in uniaxially oriented thin films enable the fabrication of broadband coatable thin film polarizers.