47 research outputs found

    A Novel Approach to Molecular Recognition Surface of Magnetic Nanoparticles Based on Host–Guest Effect

    Get PDF
    A novel route has been developed to prepared β-cyclodextrin (β-CD) functionalized magnetic nanoparticles (MNPs). The MNPs were first modified with monotosyl-poly(ethylene glycol) (PEG) silane and then tosyl units were displaced by amino-β-CD through the nucleophilic substitution reaction. The monotosyl-PEG silane was synthesized by modifying a PEG diol to form the corresponding monotosyl-PEG, followed by a reaction with 3-isocyanatopropyltriethoxysilane (IPTS). The success of the synthesis of the monotosyl-PEG silane was confirmed with1H NMR and Fourier transform infrared (FTIR) spectroscopy. The analysis of FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the immobilization of β-CD onto MNPs. Transmission electron microscopy (TEM) indicated that the β-CD functionalized MNPs were mostly present as individual nonclustered units in water. The number of β-CD molecules immobilized on each MNP was about 240 according to the thermogravimetric analysis (TGA) results. The as-prepared β-CD functionalized MNPs were used to detect dopamine with the assistance of a magnet

    Predominant Functional Expression of Kv1.3 by Activated Microglia of the Hippocampus after Status epilepticus

    Get PDF
    BACKGROUND:Growing evidence indicates that the functional state of microglial cells differs according to the pathological conditions that trigger their activation. In particular, activated microglial cells can express sets of Kv subunits which sustain delayed rectifying potassium currents (Kdr) and modulate differently microglia proliferation and ability to release mediators. We recently reported that hippocampal microglia is in a particular activation state after a status epilepticus (SE) and the present study aimed at identifying which of the Kv channels are functionally expressed by microglia in this model. METHODOLOGY/PRINCIPAL FINDINGS:SE was induced by systemic injection of kainate in CX3CR1(eGFP/+) mice and whole cell recordings of fluorescent microglia were performed in acute hippocampal slices prepared 48 h after SE. Microglia expressed Kdr currents which were characterized by a potential of half-maximal activation near -25 mV, prominent steady-state and cumulative inactivations. Kdr currents were almost abolished by the broad spectrum antagonist 4-Aminopyridine (1 mM). In contrast, tetraethylammonium (TEA) at a concentration of 1 mM, known to block Kv3.1, Kv1.1 and 1.2 subunits, only weakly reduced Kdr currents. However, at a concentration of 5 mM which should also affect Kv1.3 and 1.6, TEA inhibited about 30% of the Kdr conductance. Alpha-dendrotoxin, which selectively inhibits Kv1.1, 1.2 and 1.6, reduced only weakly Kdr currents, indicating that channels formed by homomeric assemblies of these subunits are not important contributors of Kdr currents. Finally, agitoxin-2 and margatoxin strongly inhibited the current. CONCLUSIONS/SIGNIFICANCE:These results indicate that Kv1.3 containing channels predominantly determined Kdr currents in activated microglia after SE

    Female Institutional Directors on Boards and Firm Value

    Get PDF
    The aim of this research is to examine what impact female institutional directors on boards have on corporate performance. Previous research shows that institutional female directors cannot be considered as a homogeneous group since they represent investors who may or may not maintain business relations with the companies on whose corporate boards they sit. Thus, it is not only the effect of female institutional directors as a whole on firm value that has been analysed, but also the impact of pressure-resistant female directors, who represent institutional investors (investment, pension and mutual funds) that only invest in the company, and do not maintain a business relation with the firm. We hypothesize that there is a non-linear association, specifically quadratic, between institutional and pressure-resistant female directors on boards and corporate performance. Our results report that female institutional directors on boards enhance corporate performance, but when they reach a certain threshold on boards (11.72 %), firm value decreases. In line with female institutional directors, pressure-resistant female directors on boards also increase firm value, but only up to a certain figure (12.71 % on boards), above which they have a negative impact on firm performance. These findings are consistent with an inverted U-shaped relationship between female institutional directors and pressure-resistant female directors and firm performance

    RhoE function is regulated by ROCK I-mediated phosphorylation

    No full text
    The Rho GTPase family member RhoE regulates actin filaments partly by binding to and inhibiting ROCK I, a serine/threonine kinase that induces actomyosin contractility. Here, we show that ROCK I can phosphorylate multiple residues on RhoE in vitro. In cells, ROCK I-phosphorylated RhoE localizes in the cytosol, whereas unphosphorylated RhoE is primarily associated with membranes. Phosphorylation has no effect on RhoE binding to ROCK I, but instead increases RhoE protein stability. Using phospho-specific antibodies, we show that ROCK phosphorylates endogenous RhoE at serine 11 upon cell stimulation with platelet-derived growth factor, and that this phosphorylation requires an active protein kinase C signalling pathway. In addition, we demonstrate that phosphorylation of RhoE correlates with its activity in inducing stress fibre disruption and inhibiting Ras-induced transformation. This is the first demonstration of an endogenous Rho family member being phosphorylated in vivo and indicates that phosphorylation is an important mechanism to control the stability and function of this GTPase-deficient Rho protein

    Leisure participation patterns and gender wage gap—evidence from Chinese manufacturing industry

    Get PDF
    Background: This paper aims at explaining the gender wage gap in the labor market from the perspective of leisure participation patterns between men and women. The traditional view is that time and effort spent in childbearing activities are the major sources of gender wage gap. Women, particularly in Chinese society, are the major career of children and share a large portion of housework, thus lacking time for the accumulation of human capital. This directly affects women’s employment status in the labor market as well as wage gaps with men. Methods: This study empirically examines the within-job wage differences between men and women in the same occupation and establishment in relationship to their leisure participation patterns. Data were collected via time diary survey from “blue-collar” employees of a Chinese factory, producing parts for cars. Results: The results showed that differences of time allocation in social time and passive leisure time between men and women contribute to gender wage gap. The study also uncovered the hidden gender discrimination in a male-dominated society. Conclusion: This study calls for institutional arrangements by the Chinese government to acknowledge women’s need and rights in workplace.Full Tex
    corecore