149 research outputs found
Closing the gap between spatial and spin dynamics of electrons at the metal-to-insulator transition
We combine extensive precision measurements of the optically detected spin
dynamics and magneto-transport measurements in a contiguous set of n-doped bulk
GaAs structures in order to unambiguously unravel the intriguing but complex
contributions to the spin relaxation at the metal-to-insulator transition
(MIT). Just below the MIT, the interplay between hopping induced loss of spin
coherence and hyperfine interaction yields a maximum spin lifetime exceeding
800~ns. At slightly higher doping concentrations, however, the spin relaxation
deviates from the expected Dyakonov-Perel mechanism which is consistently
explained by a reduction of the effective motional narrowing with increasing
doping concentration. The reduction is attributed to the change of the dominant
momentum scattering mechanism in the metallic impurity band where scattering by
local conductivity domain boundaries due to the intrinsic random distribution
of donors becomes significant. Here, we fully identify and model all intricate
contributions of the relevant microscopic scattering mechanisms which allows
the complete quantitative modeling of the electron spin relaxation in the
entire regime from weakly interacting up to fully delocalized electrons
Measurement of immunoreactive Interleukin-1 beta from human mononuclear cells : optimization of recovery, Intrasubject consistency, and comparison with interleukin-1 and tumor necrosis factor
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Concentrations of immunoreactive human tumor necrosis factor alpha produced by human mononuclear cells in vitro
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The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumor necrosis factor by mononuclear cells
Contains fulltext :
4487.pdf (publisher's version ) (Open Access
Cadherin-9 Is a Novel Cell Surface Marker for the Heterogeneous Pool of Renal Fibroblasts
BACKGROUND: Interstitial fibroblasts are a minor, but nevertheless very important, component of the kidney. They secrete and remodel extracellular matrix and they produce active compounds such as erythropoietin. However, studying human renal fibroblasts has been hampered by the lack of appropriate surface markers. METHODS AND FINDINGS: The expression of cadherin-9 in various human renal cell lines and tissues was studied on the mRNA level by RT-PCR and on the protein level with the help of newly generated cadherin-9 antibodies. The classical type II cadherin-9, so far only described in the neural system, was identified as a reliable surface marker for renal fibroblasts. Compared to FSP1, a widely-used cytosolic renal fibroblast marker, cadherin-9 showed a more restricted expression pattern in human kidney. Under pathological conditions, cadherin-9 was expressed in the stroma of renal cell carcinoma, but not in the tumor cells themselves, and in renal fibrosis the percentage of cadherin-9-positive cells was clearly elevated 3 to 5 times compared to healthy kidney tissue. Induction of epithelial mesenchymal transition in renal epithelial cells with cyclosporin-A, which causes renal fibrosis as a side effect, induced cadherin-9 expression. Functional studies following siRNA-mediated knockdown of cadherin-9 revealed that it acts in the kidney like a typical classical cadherin. It was found to be associated with catenins and to mediate homophilic but not heterophilic cell interactions. CONCLUSIONS: Cadherin-9 represents a novel and reliable cell surface marker for fibroblasts in healthy and diseased kidneys. Together with the established marker molecules FSP1, CD45 and alpha smooth muscle actin, cadherin-9 can now be used to differentiate the heterogenic pool of renal fibroblasts into resident and activated fibroblasts, immigrated bone marrow derived fibroblast precursors and cells in different stages of epithelial mesenchymal transition
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