The measured delamination toughness of the various tie-layers was quantitatively correlated to the length of the damage zone that formed at the crack tip. In addition, the effect of the tie-layer thickness on the multilayer tensile properties was correlated with the delamination behavior. The fracture strain of the multi-layers decreased with decreasing tie-layer thickness. An examination of the prefracture damage mechanism of the stretched multilayers
revealed a good correlation with the delamination toughness of the tie-layers. In thick tie-layers (>2 mu m), the delamination toughness was great enough to prevent the delamination of the multilayers when Emricasan nmr they were stretched. In thin tie-layers (<2 mu m), the delamination toughness of all the tie-layers was low; consequently, delamination led to premature fracture in the stretched multilayers. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121:1999-2012, 2011″
“DNA in eukaryotes is packaged into a chromatin complex, the most basic element of which is the nucleosome. The precise positioning of the nucleosome
cores allows for selective access BEZ235 concentration to the DNA, and the mechanisms that control this positioning are important pieces of the gene expression puzzle. We describe a large-scale nucleosome pattern that jointly characterizes the nucleosome core and the adjacent linkers and is predominantly characterized by long-range oscillations in the mono, di- and tri-nucleotide content of the DNA sequence, and we show that this pattern can be used to predict nucleosome positions in both Homo sapiens and Saccharomyces cerevisiae more accurately than previously published methods. Surprisingly, in both H. sapiens and S. cerevisiae, the most informative individual features are the mono-nucleotide patterns, although the inclusion of di- and tri-nucleotide features Blebbistatin clinical trial results in improved performance. Our approach combines a much longer pattern than has been previously used to predict nucleosome positioning from sequence-301 base pairs, centered at the position to be scored-with a novel discriminative
classification approach that selectively weights the contributions from each of the input features. The resulting scores are relatively insensitive to local AT-content and can be used to accurately discriminate putative dyad positions from adjacent linker regions without requiring an additional dynamic programming step and without the attendant edge effects and assumptions about linker length modeling and overall nucleosome density. Our approach produces the best dyad-linker classification results published to date in H. sapiens, and outperforms two recently published models on a large set of S. cerevisiae nucleosome positions. Our results suggest that in both genomes, a comparable and relatively small fraction of nucleosomes are well-positioned and that these positions are predictable based on sequence alone.