396 research outputs found

    c-Lysozyme promotes proliferation of chicken embryonic fibroblast through bFGF pathway

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    The egg white (EW) contains the majority of bioactive components which maintain embryo growth and differentiation. The discovery of new growth promoting factor in egg white will provide vital clue to understand the developmental regulation of early chicken embryo. The egg white heated with different temperatures (63.5, 70 and 95°C) underwent testing on its growth-promoting effect on chicken fibroblast in vitro. The purified c-lysozyme and the expression of related genes in basic fibroblast growth factor (bFGF) pathway were analyzed to ascertain its growth-promoting mechanism. 13 h after egg white treatment, more fibroblast synchronized with serum starvation transited into S phrase from G0/G1 in EW group than in the control group (CM) and reached the phase of peak proliferation at 15 h after treatment. It was found that c-lysozyme had the function of promoting cells growth and was decided by gradient heat inactivation of egg white. The addition of more than 0.25 mg/ml c-lysozyme produced significant increase in the cellular proliferation during 48 to 72 h of culture. At 13 h after c-lysozyme treatment, the bFGF, cyclin D, cyclin A and CDK2 were up-regulated significantly and promoted the transition from G0/G1 into S phrase and the accurate completion of S phrase. C-Lysozyme contains a growth-activating domain to promote the cell proliferation besides its anti-microbe domain.Key words: c-Lysozyme, fibroblast, fibroblast growth factor receptor (FGFR), cell cycle

    Effectively control negative thermal expansion of single-phase ferroelectrics of PbTiO3-(Bi,La)FeO3 over a giant range

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    Control of negative thermal expansion is a fundamentally interesting topic in the negative thermal expansion materials in order for the future applications. However, it is a challenge to control the negative thermal expansion in individual pure materials over a large scale. Here, we report an effective way to control the coefficient of thermal expansion from a giant negative to a near zero thermal expansion by means of adjusting the spontaneous volume ferroelectrostriction (SVFS) in the system of PbTiO3-(Bi,La) FeO3 ferroelectrics. The adjustable range of thermal expansion contains most negative thermal expansion materials. The abnormal property of negative or zero thermal expansion previously observed in ferroelectrics is well understood according to the present new concept of spontaneous volume ferroelectrostriction. The present studies could be useful to control of thermal expansion of ferroelectrics, and could be extended to multiferroic materials whose properties of both ferroelectricity and magnetism are coupled with thermal expansion

    Cluster aggregates surrounding Pismis 5 in the Vela Molecular Ridge

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    Context. In the Gaia era, the precision of astrometric data is unprecedented. High-quality data make it easier to find more cluster aggregates and support further confirmation of these open clusters. Aims. We use Gaia DR3 to redetermine the open clusters surrounding Pismis 5 in the Vela Molecular Ridge. We also investigate the basic properties of these clusters. Methods. We apply two clustering algorithms (StarGO and pyUPMASK) to identify the open cluster members in a five-dimensional space with Gaia DR3. Results. We identify eight open clusters surrounding Pismis 5 in the Vela Molecular Ridge. The open cluster QZ 1 is newly discovered. Through investigating the comprehensive properties of the clusters, one open binary cluster candidate (Alessi 43 and Collinder 197) and one triple open cluster candidate (Pismis 5, Pismis 5A, and Pismis 5B) are discussed. Conclusions. Binary and triple open cluster candidates have been identified as potential primordial aggregates based on their similar age, position, and motion. According to kinematic speculations, the two aggregate candidates will gradually separate, and their interiors will slowly disintegrate.Comment: 10 pages, 7 figure

    Film-through large perovskite grains formation via a combination of sequential thermal and solvent treatment

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    Organic–inorganic halide perovskites have recently attracted strong research interest for fabrication of high-performance, lowcost photovoltaic devices. Recently, we reported a highly reproducible procedure to fabricate high-performance organic–inorganic halide perovskite solar cells. This procedure, based on a onestep, solvent-induced, fast deposition-crystallization method, involves the use of sec-butyl alcohol as a new solvent to induce the CH3NH3PbI3 fast crystallization deposition. In the present study, we propose a reproducible fabrication method to prepare both flat and large-grain perovskite film by adding a pre-annealing step to strengthen the perovskite nucleation, aiming to facilitate the excess CH3NH3I and solvent removal in the sec-butyl alcohol soaking process, in which all films with thickness between 420 nm and 1µm performed uniformly. The best performing planar device obtained with this procedure had an efficiency of 17.2% under AM 1.5G illumination and an average power conversion efficiency of 16.2 ± 0.5%. We also analyzed the efficiency of halide perovskite planar solar cells as a function of the perovskite film thickness; the efficiency dropped only slightly to 15.7% when the perovskite film thickness was increased to 1µm
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