c 2010 American Institute of Physics. [doi: 10.1063/1.3310420]“
“Background: Although the function of human melanocytes is well characterized at cellular and molecular levels, the mechanism of the regulation of the life cycle (proliferation, differentiation, and cell death) of human melanocytes is not fully understood.
Objective: This Study aims to clarify what factors are involved in regulating the life
cycle of human melanocytes using serum-free culture system.
Methods: Human epidermal melanocytes were cultured in a serum-free growth medium supplemented with several kinds of growth factors, cytokines, and hormones and the effects of these factors on the life cycle of melanocytes were investigated in detail.
Results: Of the factors tested, endothelin-1 (ET-1) stimulated the proliferation of melanoblasts and melanocytes in the presence of cyclic AMP (cAMP)-elevating factor such as dibutyryl cAMP (DBcAMP) and of basic fibroblast AZD5153 price growth factor(bFGF). ET-1 also stimulated the proliferation and differentiation of human melanocytes in the presence of DBcAMP. Moreover, stem cell factor (SCF) stiniulited the
proliferation of melanoblasts and melanocytes synergistically with ET-1. The removal of ET-1 and SCF from the culture medium greatly inhibited the proliferation of melanocytes followed by apoptotic cell death.
Conclusion: These results suggest that the life cycle of human melanocytes is regulated CHIR-99021 by ET-1 and SCF in synergy with cAMP and bFGF. (C) 2009 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.”
“Heterojunction with intrinsic
thin layer or “”HIT”" solar cells are considered favorable for large-scale manufacturing of solar modules, as they combine the high efficiency of crystalline silicon (c-Si) solar cells, with the low cost of amorphous silicon technology. In this article, based on experimental data published by Sanyo, we simulate the performance of a series of HIT cells on N-type crystalline silicon substrates with hydrogenated amorphous silicon (a-Si:H) emitter layers, to gain insight into carrier transport and the general functioning of these AG-881 molecular weight devices. Both single and double HIT structures are modeled, beginning with the initial Sanyo cells having low open circuit voltages but high fill factors, right up to double HIT cells exhibiting record values for both parameters. The one-dimensional numerical modeling program “”Amorphous Semiconductor Device Modeling Program”" has been used for this purpose. We show that the simulations can correctly reproduce the electrical characteristics and temperature dependence for a set of devices with varying I-layer thickness. Under standard AM1.5 illumination, we show that the transport is dominated by the diffusion mechanism, similar to conventional P/N homojunction solar cells, and tunneling is not required to describe the performance of state-of-the art devices.