Leukaemia inhibitory factor retards the progression of atherosclerosis

Objective: Our previous studies showed that the pleiotropic cytokine leukaemia inhibitory factor (LIF) inhibits the de novo formation of experimental atherosclerotic lesions. The present study examined whether LIF also inhibits progression of pre-existing atheroma. Methods: Balloon angioplasty was performed on the right carotid arteries of 18 rabbits immediately before placing animals on a cholesterol-enriched diet. After 4 weeks, at which time the intima:media ratio (IN) was 0.99+/-0.12 (n=6), osmotic minipumps containing LIF (n=6) or saline control n=6) were inserted into the peritoneal cavity of each of the remaining rabbits for a further 4 weeks. Arteries were then harvested for analysis. Results: Continuous administration of LIF for the final 4 weeks of an 8-week cholesterol-enriched diet completely inhibited lesion progression in injured carotid arteries (I:M 1.05+/-0.16) compared with the saline-treated group at 8 weeks (1.62+/-0.13; P

Suppressor of cytokine signaling 3 limits protection of leukemia inhibitory factor receptor signaling against central demyelination

Enhancement of oligodendrocyte survival through activation of leukemia inhibitory factor receptor (LIFR) signaling is a candidate therapeutic strategy for demyelinating disease. However, in other cell types, LIFR signaling is under tight negative regulation by the intracellular protein suppressor of cytokine signaling 3 (SOCS3). We, therefore, postulated that deletion of the SOCS3 gene in oligodendrocytes would promote the beneficial effects of LIFR signaling in limiting demyelination. By studying wild-type and LIF-knockout mice, we established that SOCS3 expression by oligodendrocytes was induced by the demyelinative insult, that this induction depended on LIF, and that enclogenously produced LIF was likely to be a key determinant of the CNS response to oligodendrocyte loss. Compared with wild-type controls, oligo-dendrocyte-specific SOCS3 conditional-knockout mice displayed enhanced c-fos activation and exogenous LIF-induced phosphorylation of signal transducer and activator of transcription 3. Moreover, these SOCS3-deficient mice were protected against cupri-zone-induced oligodendrocyte loss relative to wild-type animals. These results indicate that modulation of SOCS3 expression could facilitate the endogenous response to CNS injury.

Optimization of microcavity OLED by varying the thickness of multi-layered mirror

We optimized the emission efficiency from a microcavity OLEDs consisting of widely used organic materials, N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) (Alq(3)) as emitting and electron transporting layer. LiF/Al was considered as a cathode, while metallic Ag anode was used. TiO2 and Al2O3 layers were stacked on top of the cathode to alter the properties of the top mirror. The electroluminescence emission spectra, electric field distribution inside the device, carrier density, recombination rate and exciton density were calculated as a function of the position of the emission layer. The results show that for certain TiO2 and Al2O3 layer thicknesses, light output is enhanced as a result of the increase in both the reflectance and transmittance of the top mirror. Once the optimum structure has been determined, the microcavity OLED devices can be fabricated and characterized, and comparisons between experiments and theory can be made.

Effect of anode material and cavity design on the performance of microcavity OLEDs

We report on the effect of the replacement of the conventional ITO anode with the semitransparent metallic material on the performance of microcavity OLEDs. We performed comprehensive simulations of the emission from microcavity OLEDs consisting of widely used organic materials, N,N′-di(naphthalene-1- yl)-N,N′-diphenylbenzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) (Alq3) as emitting and electron transporting layer. Silver and LiF/Al were considered as a cathode, while metallic (Au and Ag) anode was used and simulations were performed on devices with both the metallic and conventional ITO anode. The electroluminescence emission spectra, electric field distribution inside the device, carrier density, recombination rate and exciton density were calculated as a function of the position of the emission layer. The results show that the metallic anode enhances light output and that optimum emission from a microcavity OLED is achieved when the position of the recombination region is aligned with the antinode of the standing wave inside the cavity. The microcavity OLED devices with Ag/Ag and Ag/Au mirrors were fabricated and characterized. The experimental results have been compared to the simulations and the influence of the different anode, emission region width and position on the performance of microcavity OLEDs was discussed.