Silylation of layered double hydroxides via an induced hydrolysis method

A series of layered double hydroxides (LDHs) based composites were synthesized by using induced hydrolysis silylation method (IHS), surfactant precursor method, in-situ coprecipitation method, and direct silylation method. Their structures, morphologies, bonding modes and thermal stabilities can be readily adjusted by changing the parameters during preparation and drying processing of the LDHs. The characterization results show that the direct silylation reaction cannot occur between the dried LDHs and 3-aminopropyltriethoxysilane (APS) in an ethanol medium. However, the condensation reaction can proceed with heating process between adsorbed APS and LDHs plates. While using wet state substrates with and without surfactant and ethanol as the solvent, the silylation process can be induced by hydrolysis of APS on the surface of LDHs plates. Surfactants improve the hydrophobicity of the LDHs during the process of nucleation and crystallization, resulting in fluffy shaped crystals; meanwhile, they occupy the surface –OH positions and leave less “free –OH” available for the silylation reaction, favoring formation of silylated products with a higher population in the hydrolyzed bidentate (T2) and tridentate (T3) bonding forms. These bonding characteristics lead to spherical aggregates and tightly bonded particles. All silylated products show higher thermal stability than those of pristine LDHs.

CD73 and CD29 concurrently mediate the mechanically induced decrease of migratory capacity of mesenchymal stromal cells

The assumption that mesenchymal stromal cell (MSC)-based therapies are capable of augmenting physiological regeneration processes has fostered intensive basic and clinical research activities. However, to achieve sustained therapeutic success in vivo, not only the biological, but also the mechanical microenvironment of MSCs during these regeneration processes needs to be taken into account. This is especially important for e.g., bone fracture repair, since MSCs present at the fracture site undergo significant biomechanical stimulation. This study has therefore investigated cellular characteristics and the functional behaviour of MSCs in response to mechanical loading. Our results demonstrated a reduced expression of MSC surface markers CD73 (ecto-5’-nucleotidase) and CD29 (integrin β1) after loading. On the functional level, loading led to a reduced migration of MSCs. Both effects persisted for a week after the removal of the loading stimulus. Specifi c inhibition of CD73/CD29 demonstrated their substrate dependent involvement in MSC migration after loading. These results were supported by scanning electron microscopy images and phalloidin staining of actin fi laments displaying less cell spreading, lamellipodia formation and actin accumulations. Moreover, focal adhesion kinase and Src-family kinases were identified as candidate downstream targets of CD73/CD29 that might contribute to the mechanically induced decrease in MSC migration. These results suggest that MSC migration is controlled by CD73 CD29, which in turn are regulated by mechanical stimulation of cells. We therefore speculate that MSCs migrate into the fracture site, become mechanically entrapped, and thereby accumulate to fulfil their regenerative functions.

Economic development, enlightenment and creative transformation : creative industries in the New China

This paper examines some of the implications for China of the creative industries agenda as drawn by some recent commentators. The creative industries have been seen by many commentators as essential if China is to move from an imitative low-value economy to an innovative high value one. Some suggest that this trajectory is impossible without a full transition to liberal capitalism and democracy - not just removing censorship but instituting 'enlightenment values'. Others suggest that the development of the creative industries themselves will promote social and political change. The paper suggests that the creative industries takes certain elements of a prior cultural industries concept and links it to a new kind of economic development agenda. Though this agenda presents problems for the Chinese government it does not in itself imply the kind of radical democratic political change with which these commentators associate it. In the form in which the creative industries are presented – as part of an informational economy rather than as a cultural politics – it can be accommodated by a Chinese regime doing ‘business as usual’.

Workplace mobbing : expulsion, exclusion, and transformation

The issue of workplace bullying has received considerable attention in recent times in both the academic literature and in the print and electronic media. The stereotypical bullying scenario can be described as the “bully boss” model, where those in more senior positions tend to bully the staff they supervise. By way of contrast, this paper presents the findings of a three year exemplarian action research study into the lesser known phenomenon of workplace mobbing. Consistent with grounded theory methods, the findings are discussed in the context of emergent propositions in relation to the broader social, cultural, and organisational factors that can perpetuate workplace mobbing in the public sector.

Anion induced displacement studies in naphthalene diimide containing interpenetrated and interlocked structures

This article describes investigations into the development of supramolecular systems capable of sensing anions through either displacement type assays or molecular motion. An electron deficient naphthalene diimide thread and electron rich isophthalamide naphthohydroquinone macrocycle was shown to form a coloured pseudorotaxane assembly. Investigations into the ability of such interpenetrated systems to sense anions colorimetrically were undertaken. Anion complexation to the isophthalamide group of the macrocycle causes displacement of the naphthodiimide thread resulting in the loss of colour. The enhanced mechanically bonded binding strength between the naphthodiimide axle and the naphthohydroquinone groups of the macrocycle wheel in the corresponding rotaxane structure however, was found to negate the anion induced displacement process.