A New Reversible Colorimetric Chemosensor Based on Julolidine Moiety for Detecting F−

Journal of Fluorescence - We synthesized an original reversible colorimetric chemosensor PDJ...     

Curcumin inhibits cellular condensation and alters microfilament organization during chondrogenic differentiation of limb bud mesenchymal cells

Curcumin is a well known natural polyphenol product isolated from the rhizome of the plant Curcuma longa, anti-inflammatory agent for arthritis by inhibiting synthesis of inflammatory prostaglandins. However, the mechanisms by which curcumin regulates the functions of chondroprogenitor, such as proliferation, precartilage condensation, cytoskeletal organization or overall chondrogenic behavior, are largely unknown. In the present report, we investigated the effects and signaling mechanism of curcumin on the regulation of chondrogenesis. Treating chick limb bud mesenchymal cells with curcumin suppressed chondrogenesis by stimulating apoptotic cell death. It also inhibited reorganization of the actin cytoskeleton into a cortical pattern concomitant with rounding of chondrogenic competent cells and down-regulation of integrin β1 and focal adhesion kinase (FAK) phosphorylation. Curcumin suppressed the phosphorylation of Akt leading to Akt inactivation. Activation of Akt by introducing a myristoylated, constitutively active form of Akt reversed the inhibitory actions of curcumin during chondrogenesis. In summary, for the first time, we describe biological properties of curcumin during chondrogenic differentiation of chick limb bud mesenchymal cells. Curcumin suppressed chondrogenesis by stimulating apoptotic cell death and down-regulating integrin-mediated reorganization of actin cytoskeleton via modulation of Akt signaling.     

Complexation of phthalate oxygens in poly(ethylene phthalate) with silver ions and its effect on the formation of silver nanoparticles

The interaction of a phthalate group in poly(ethylene phthalate) (PEP) with silver ion has been elaborated in detail to understand the reduction behavior of silver ions to silver nanoparticles. Previously, the polymer electrolytes consisting of silver ions dissolved in PEP have shown highly stable separation performance for propylene/propane mixtures primarily due to the retardation of the reduction reaction of silver ions to silver nanoparticles, which is possible by means of the chelating bonds between phthalate groups and silver ions. Thus, in this study, the interaction was systematically investigated by both the theoretical ab initio calculation and the experimental Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. The results show that the interaction of silver ion with phthalate group in PEP is approximately two times stronger than that with other functional groups such as amide, ketone, and ester in various polymers, in which the latter ones show the rapid reduction reaction and consequently lose their olefin carrier activity with time. Therefore, it is concluded that the reduction reaction of silver ions to silver nanoparticles is retarded remarkably in PEP/silver salts systems primarily because of the strong interaction between the phthalate group in PEP and silver ion, and consequently the formation of silver nanoparticles would be effectively prohibited, as confirmed by transmission electron microscopy and ultraviolet–visible spectroscopy. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3344–3350, 2004     

TiO2 nanotube stimulate chondrogenic differentiation of limb mesenchymal cells by modulating focal activity

Vertically aligned, laterally spaced nanoscale titanium nanotubes were grown on a titanium surface by anodization, and the growth of chondroprogenitors on the resulting surfaces was investigated. Surfaces bearing nanotubes of 70 to 100 nm in diameter were found to trigger the morphological transition to a cortical actin pattern and rounded cell shape (both indicative of chondrocytic differentiation), as well as the up-regulation of type II collagen and integrin beta4 protein expression through the down-regulation of Erk activity. Inhibition of Erk signaling reduced stress fiber formation and induced the transition to the cortical actin pattern in cells cultured on 30-nm-diameter nanotubes, which maintained their fibroblastoid morphologies in the absence of Erk inhibition. Collectively, these results indicate that a titanium-based nanotube surface can support chondrocytic functions among chondroprogenitors, and may therefore be useful for future cartilaginous applications.     

IL-30† (IL-27A): a familiar stranger in immunity,inflammation, and cancer

Over the years, interleukin (IL)-27 has received much attention because of its highly divergent, sometimes even opposing, functions in immunity. IL-30, the p28 subunit that forms IL-27 together with Ebi3 and is also known as IL-27p28 or IL-27A, has been considered a surrogate to represent IL-27. However, it was later discovered that IL-30 can form complexes with other protein subunits, potentially leading to overlapping or discrete functions. Furthermore, there is emerging evidence that IL-30 itself may perform immunomodulatory functions independent of Ebi3 or other binding partners and that IL-30 production is strongly associated with certain cancers in humans. In this review, we will discuss the biology of IL-30 and other IL-30-associated cytokines and their functions in inflammation and cancer.Subject terms: Interleukins, Cytokines     

Highly Selective Detection of Al3+ by Carboxamide-Based Fluorescent Chemosensor

We designed a carboxamide-based fluorescent chemosensor HTPQ ((E)-2-(((8-hydroxy-2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)amino)thiophene-3-carboxamide) for detecting Al³⁺. HTPQ could probe Al³⁺ by fluorescence enhancement. Limit of detection for Al³⁺ toward HTPQ was 1.4 μM. Binding of HTPQ to Al³⁺ was determined to be a 1:1 ratio with the analysis of Job plot and ESI-mass. In addition, HTPQ was able to detect Al³⁺ using the test strip by fluorescent variation. The sensing process of Al³⁺ by HTPQ was presented by UV–vis titration, ESI–MS, Job plot, ¹H NMR titration and DFT calculation.

     

Enhanced speciation in particle swarm optimization for multi-modal problems

In this paper, we present a novel multi-modal optimization algorithm for finding multiple local optima in objective function surfaces. We build from Species-based particle swarm optimization (SPSO) by using deterministic sampling to generate new particles during the optimization process, by implementing proximity-based speciation coupled with speciation of isolated particles, and by including “turbulence regions” around already found solutions to prevent unnecessary function evaluations. Instead of using error threshold values, the new algorithm uses the particle’s experience, geometric mean, and “exclusion factor” to detect local optima and stop the algorithm. The performance of each extension is assessed with leave-it-out tests, and the results are discussed. We use the new algorithm called Isolated-Speciation-based particle swarm optimization (ISPSO) and a benchmark algorithm called Niche particle swarm optimization (NichePSO) to solve a six-dimensional rainfall characterization problem for 192 rain gages across the United States. We show why it is important to find multiple local optima for solving this real-world complex problem by discussing its high multi-modality. Solutions found by both algorithms are compared, and we conclude that ISPSO is more reliable than NichePSO at finding optima with a significantly lower objective function value.