Amine Dynamics in Diamine-Appended Mg2(dobpdc) Metal-Organic Frameworks.

Variable-temperature 15N solid-state NMR spectroscopy is used to uncover the dynamics of three diamines appended to the metal-organic framework Mg2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate), an important family of CO2 capture materials. The results imply both bound and free amine nitrogen environments exist when diamines are coordinated to the framework open Mg2+ sites. There are rapid exchanges between two nitrogen environments for all three diamines, the rates and energetics of which are quantified by 15N solid-state NMR data and corroborated by density functional theory calculations and molecular dynamics simulations. The activation energy for the exchange provides a measure of the metal-amine bond strength. The unexpected negative correlation between the metal-amine bond strength and CO2 adsorption step pressure reveals that metal-amine bond strength is not the only important factor in determining the CO2 adsorption properties of diamine-appended Mg2(dobpdc) metal-organic frameworks

Mutation in SUMO E3 ligase, SIZ1, Disrupts the Mature Female Gametophyte in Arabidopsis

Female gametophyte is the multicellular haploid structure that can produce embryo and endosperm after fertilization, which has become an attractive model system for investigating molecular mechanisms in nuclei migration, cell specification, cell-to-cell communication and many other processes. Previous reports found that the small ubiquitin-like modifier (SUMO) E3 ligase, SIZ1, participated in many processes depending on particular target substrates and suppression of salicylic acid (SA) accumulation. Here, we report that SIZ1 mediates the reproductive process. SIZ1 showed enhanced expression in female organs, but was not detected in the anther or pollen. A defect in the siz1-2 maternal source resulted in reduced seed-set regardless of high SA concentration within the plant. Moreover, aniline blue staining and scanning electron microscopy revealed that funicular and micropylar pollen tube guidance was arrested in siz1-2 plants. Some of the embryo sacs of ovules in siz1-2 were also disrupted quickly after stage FG7. There was no significant affects of the siz1-2 mutation on expression of genes involved in female gametophyte development- or pollen tube guidance in ovaries. Together, our results suggest that SIZ1 sustains the stability and normal function of the mature female gametophyte which is necessary for pollen tube guidance

Conditional Deletion of PDK1 in the Forebrain Causes Neuron Loss and Increased Apoptosis during Cortical Development

Decreased expression but increased activity of PDK1 has been observed in neurodegenerative disease. To study in vivo function of PDK1 in neuron survival during cortical development, we generate forebrain-specific PDK1 conditional knockout (cKO) mice. We demonstrate that PDK1 cKO mice display striking neuron loss and increased apoptosis. We report that PDK1 cKO mice exhibit deficits on several behavioral tasks. Moreover, PDK1 cKO mice show decreased activities for Akt and mTOR. These results highlight an essential role of endogenous PDK1 in the maintenance of neuronal survival during cortical development

Quantification of the effect of colour appearance and materials on the visual-tactile properties of fabrics

This paper presents the results of experiments to evaluate the human perception of the visual-tactile properties: flexible-stiff, smooth-rough and soft-firm of fabrics as seen on a mobile-phone display. The aim of this study was to test whether different colours and different fabrics have significant effects on these properties, and to evaluate the differences between the effects of these parameters. Eighty images, representing four fabrics and 20 colours, were used to judge the human responses to tactile properties. The results showed that observers can be significantly affected by colour when assessing smoothness, roughness, softness and firmness on woollen wool fabric, while most colours have no significant effect on the human perception of flexibility and stiffness. Fabric materials which have different textures have more significant effects than colour for smoothness, roughness, softness and firmness, but there is little difference between the effects of colour and fabric material when assessing flexibility and stiffnes

Thermal elastomer composites for soft transducers

Thermal elastomer composites (TECs) that are electrically insulating have potential usage in soft transducers targeting thermal sensors and actuators, or thermoelectric generators. In this work, such a TEC is prepared by dispersing droplets of a gallium based liquid alloy (Galinstan) into a polydimethysiloxane (PDMS) base matrix. The results indicate that the TEC is highly elastic and shows an up to three-fold increase in thermal conductivity from that of PDMS. A thermoelectric device with the TEC packaging is demonstrated with a higher efficiency than that with pristine PDMS packaging