High temperature optical absorption investigation into the electronic transitions in sol–gel derived C12A7 thin films

Optical absorption into 6 mm thick sol–gel derived films, annealed at 1300 °C of 12CaO·7Al2O3 calcium aluminate binary compound on MgO〈100〉 single crystal substrates was studied at temperatures ranging from room temperature to 300 °C. Experimental data were analysed in both Tauc and Urbach regions. The optical band gap decreased from 4.088 eV at 25 °C to 4.051 eV at 300 °C, while Urbach energy increased from 0.191 eV at 25 °C to 0.257 eV at 300 °C. The relationship between the optical band gap and the Urbach energy at different temperatures showed an almost linear relationship from which the theoretical values of 4.156 and 0.065 eV were evaluated for the band gap energy and Urbach energy of a 12CaO·7Al2O3 crystal with zero structural disorder at 0 K

Effect of transforming growth factor-β2 on biological regulation of multilayer primary chondrocyte culture

YesCytokines are extremely potent biomolecules that regulate cellular functions and play multiple roles in initiation and inhibition of disease. These highly specialised macromolecules are actively involved in control of cellular proliferation, apoptosis, cell migration and adhesion. This work, investigates the effect of transforming growth factor-beta2 (TGF-β2) on the biological regulation of chondrocyte and the repair of a created model wound on a multilayer culture system. Also the effect of this cytokine on cell length, proliferation, and cell adhesion has been investigated. Chondrocytes isolated from knee joint of rats and cultured at 4 layers. Each layer consisted of 2 × 105 cells/ml with and without TGF-β2. The expression of mRNA and protein levels of TGF-β receptors and Smad1, 3, 4, and 7 have been analysed by RT-PCR and western blot analysis. The effect of different supplementations in chondrocyte cell proliferation, cell length, adhesion, and wound repair was statistically analysed by One-way ANOVA test. Our results showed that the TGFβ2 regulates mRNA levels of its own receptors, and of Smad3 and Smad7. Also the TGF-β2 caused an increase in chondrocyte cell length, but decreased its proliferation rate and the wound healing process. TGF-β2 also decreased cell adhesion ability to the surface of the culture flask. Since, TGF-β2 increased the cell size, but showed negative effect on cell proliferation and adhesion of CHC, the effect of manipulated TGF-β2 with other growth factors and/or proteins needs to be investigated to finalize the utilization of this growth factor and design of scaffolding in treatment of different types of arthritis

Glutathione S-Transferase Pi Isoform (GSTP1) Expression in Murine Retina Increases with Developmental Maturity

BACKGROUND AND AIMS: Glutathione S-transferase pi isoform (GSTP1) is an intracellular detoxification enzyme that catalyzes reduction of chemically reactive electrophiles and is a zeaxanthin-binding protein in the human macula. We have previously demonstrated that GSTP1 levels are decreased in human age-related macular degeneration (AMD) retina compared to normal controls [1]. We also showed that GSTP1 levels parallel survival of human retinal pigment epithelial (RPE) cells exposed to UV light, and GSTP1 over-expression protects them against UV light damage [2]. In the present work, we determined the developmental time course of GSTP1 expression in murine retina and in response to light challenge. METHODS: Eyes from BALB/c mice at post-natal day 20, 1 month, and 2 months of age were prepared for retinal protein extraction and cryo sectioning, and GSTP1 levels in the retina were analyzed by Western blot and immunohistochemistry (IHC). Another group of BALB/c mice with the same age ranges was exposed to 1000 lux of white fluorescent light for 24 hours, and their retinas were analyzed for GSTP1 expression by Western blot and IHC in a similar manner. RESULTS: GSTP1 levels in the murine retina increased in ascending order from post-natal day 20, 1 month, and 2 months of age. Moreover, GSTP1 expression in murine retina at post-natal day 20, 1 month, and 2 months of age increased in response to brief light exposure compared to age-matched controls under normal condition. CONCLUSIONS: GSTP1 expression in retina increases with developmental age in mice and accompanies murine retinal maturation. Brief exposure to light induces GSTP1 expression in the murine retina across various developmental ages. GSTP1 induction may be a protective response to light-induced oxidative damage in the murine retina