Correction: Effects of droplet size and surfactants on anchoring in liquid crystal nanodroplets

Correction for ‘Effects of droplet size and surfactants on anchoring in liquid crystal nanodroplets’ by Zeynep Sumer et al., Soft Matter, 2019, 15, 3914–3922, DOI: 10.1039/C9SM00291J

Nanoparticles shape-specific emergent behaviour on liquid crystal droplets

Self-assembly attracts enormous research attention because it is at the core of important applications ranging from medical treatments to renewable energy production. Among several classes of self-assembling materials, liquid crystals (LCs) and nanoparticles yield ordered structures under well-defined thermodynamic conditions and could yield supra-molecular aggregates, respectively. In this work, nanoparticle self-assembly on LC nano-droplets is investigated. The LC nano-droplets act as templating agents on which homogeneous and Janus nanoparticles of various geometrical features are adsorbed. LC mesogens and water have low mutual solubility, and under the conditions chosen the LCs yield bipolar nano-droplets. Particle self-assembly on oil nano-droplets is also considered for comparison. Our results reveal that the mesogens can direct the assembly of the nanoparticles. This effect is mainly governed by the nanoparticle size and shape. In some cases, strong evidence of emergent behaviour is observed depending on entropic forces that arise because of the shape and patchiness of the nanoparticles. For example, while one small spherical homogeneous particle does not show preferential adsorption on specific LC nano-droplet locations, 100 spherical nanoparticles preferentially agglomerate at the nano-droplet boojums, providing evidence of emergent behaviour. On the contrary, Janus spherical nanoparticles do not show such a strong emergent behaviour. Cylindrical NPs manifest the opposite trend: while homogeneous nano-cylinders do not exhibit orientational order on the LC nano-droplet, Janus ones either locate at the LC nano-droplet boojums or orient towards the direction vector of bipolar droplets. Quantification of the orientational order within the LC nano-droplets suggests that the self-assembly of the LC mesogens does not significantly change upon nanoparticle adsorption. These simulations clearly suggest an interplay between nanoparticle size, shape and chemical composition upon their self-assembly on LC nano-droplets. The results could be helpful for the design of new sensors and for the directed self-assembly of advanced materials

Cross-modal investigation of event component omissions in language development: A comparison of signing and speaking children

Language development research suggests a universal tendency for children to be under- informative in narrating motion events by omitting components such as Path, Manner or Ground. However, this assumption has not been tested for children acquiring sign language. Due to the affordances of the visual-spatial modality of sign languages for iconic expression, signing children might omit event components less frequently than speaking children. Here we analysed motion event descriptions elicited from deaf children (4–10 years) acquiring Turkish Sign Language (TİD) and their Turkish-speaking peers. While children omitted all types of event components more often than adults, signing children and adults encoded more Path and Manner in TİD than their peers in Turkish. These results provide more evidence for a general universal tendency for children to omit event components as well as a modality bias for sign languages to encode both Manner and Path more frequently than spoken languages

Liquid crystal droplets under extreme confinement probed by a multiscale simulation approach

In this work, we computationally investigate liquid crystal (LC) droplets in the size range 0.03–1 μm, confined within shells of combined anchoring conditions. Two different types of surface were defined to promote homeotropic and planar degenerate anchoring, respectively. We identified the LC behaviour within the nanoscale droplets using a bespoke multiscale simulation approach. To study 30 nm droplets, we used coarse grained simulations within the dissipative particle dynamics formalism; to study 0.1 μm and larger droplets, we used a finite element method based on the Landau–de Gennes theory. Good agreement between the two methods was observed in our prior analysis and was confirmed in the present work. We explicitly study droplets of size 0.1 and 1 μm by using continuum mechanics calculations. Our results for the largest droplet are consistent with those available in the literature, suggesting that the extension to smaller droplets presented here is realistic, and therefore can be helpful for innovations in which device intensification could be achieved using LC nanodroplets

Engineered liquid crystal nano droplets: insights from multi-scale simulations

Liquid crystal (LC) droplets have been investigated for a wide range of applications, from displays to sensors. Over the years, a need has arisen for complete understanding of the behaviour of LCs in droplets under different conditions for the development of advanced devices, for which accurate modelling is necessary. We show here, for the first time, both qualitative and quantitative agreement between coarse-grained molecular models and Q-tensor theory calculations for liquid crystal (LC) droplets. The approach is demonstrated for two types of droplet surfaces, which possess strong planar degenerate and strong homeotropic anchoring, respectively. Once its reliability has been proven, our approach was used to identify defects due to changes in anchoring in a small region on the LC droplet surface, which could be triggered, for example, by the adsorption of a nano-particle or a protein. Both coarse-grained simulations and Q-tensor analysis show the appearance of defects in well-determined locations within the LC droplet, albeit sometimes affected by degeneracy due to the symmetry of the systems being investigated. These results suggest the possibility of using LC droplets, in the future, as platforms for advanced sensing as well as for signal intensification

Late sign language exposure does not modulate the relation between spatial language and spatial memory in deaf children and adults

Prior work with hearing children acquiring a spoken language as their first language shows that spatial language and cognition are related systems and spatial language use predicts spatial memory. Here, we further investigate the extent of this relationship in signing deaf children and adults and ask if late sign language exposure, as well as the frequency and the type of spatial language use that might be affected by late exposure, modulate subsequent memory for spatial relations. To do so, we compared spatial language and memory of 8-year-old late-signing children (after 2 years of exposure to a sign language at the school for the deaf) and late-signing adults to their native-signing counterparts. We elicited picture descriptions of Left-Right relations in Turkish Sign Language (Türk İşaret Dili) and measured the subsequent recognition memory accuracy of the described pictures. Results showed that late-signing adults and children were similar to their native-signing counterparts in how often they encoded the spatial relation. However, late-signing adults but not children differed from their native-signing counterparts in the type of spatial language they used. However, neither late sign language exposure nor the frequency and type of spatial language use modulated spatial memory accuracy. Therefore, even though late language exposure seems to influence the type of spatial language use, this does not predict subsequent memory for spatial relations. We discuss the implications of these findings based on the theories concerning the correspondence between spatial language and cognition as related or rather independent systems

Determination of Physiological, Biochemical and Molecular Effects of Zinc Stress on the Growth of Sunflower Seedlings (Helianthus annuus L.)

Heavy metal contamination is an important environmental problem all over the world. High concentrations of heavy metals cause permanent damage stocells and tissues. In this study, the toxic effects of zincheavy metal in sunflower plant in population and molecular parameters were investigated. The effects of zincheavymetalon sunflower seedlings were determined using the changes in population parameters; rootlength, dry weight, and total solubleprotein content. Total protein content of sunflower plants was determined in a relationship in the opposite direction increasing the amount of metal concentrations. Genotoxic effects of heavymetal of zinc on sunflower plants were revealed by using changes in genomic template stability (GTS). According to analyses, serious changes in genomic template stability were detected and these results were compared with the growth, dry weight and total soluble protein content of the seedlings grown at various zinc concentrations. Also, it was seen that the genomic template stability significantly affected the primary root length, root dry weight and root total soluble protein content. Positive correlations were observed between physiological, biochemical and molecular parameters in sunflower seedlings under zinc stress.In conclusion, a comparison between physiological, biochemical and molecular parameters shows that zinc is a genotoxic agent for sunflower plants