The presence of blue stragglers pose challenges to standard stellar evolution theory, in the sense that explaining their presence demands a complex interplay between stellar evolution and cluster dynamics. In the meantime, mass transfer in binary systems and stellar collisions are widely studied as a blue straggler formation channel. We explore properties of the Galactic open clusters where blue stragglers are found, in attempting to estimate the relative importance of these two favored processes, by comparing them with those resulting from open clusters in which blue stragglers are absent as of now. Unlike previous studies which require a sophisticated process in understanding the implication of the results, this approach is straightforward and has resulted in a supplementary supporting evidence for the current view on the blue straggler formation mechanism. Our main findings are as follows: (1) Open clusters in which blue stragglers are present have a broader distribution with respect to the Z-axis pointing towards the North Galactic Pole than those in which blue stragglers are absent. The probability that two distributions with respect to the Z-axis are drawn from the same distribution is 0.2%. (2) Average values of log10(t) of the clusters with blue stragglers and those without blue stragglers are 8.58 ± 0.232 and 7.52 ± 0.285, respectively. (3) The clusters with blue stragglers tend to be relatively redder than the others, and are distributed broader in colors. (4) The clusters with blue stragglers are likely brighter than those without blue stragglers. (5) Finally, blue stragglers seem to form in condensed clusters rather than simply dense clusters. Hence, we conclude that mass transfer in binaries seems to be a relatively important physical mechanism of the generation of blue stragglers in open clusters, provided they are sufficiently old.

Pleurotus eryngii (also known as king trumpet mushroom, french horn mushroom, king oyster mushroom) is an edible mushroom native to Mediterranean regions of Europe, the Middle East, and North Africa, but also grown in parts of Asia. It has the ability to produce various biologically active compounds and possesses a well-developed ligninolytic enzyme system that participates in the degradation of lignin and different aromatic compounds. In this study, we investigated the protective effects of the ethyl acetate extract of Pleurotus eryngii (PEE) on the development of atopic dermatitis (AD) in human keratinocyte HaCaT cells. Keratinocytes, one of major cell types in the skin, can be induced by TNF-α and IFN-γ to express thymus and activation-regulated chemokine (TARC/CCL17), which is considered to be a pivotal mediator in the inflammatory responses during the development of inflammatory skin diseases, such as AD. In addition, normal T-cell–expressed and secreted chemokine (RANTES) is a (C-C) chemokine released by T lymphocytes, other inflammatory cells, and platelets and plays an important role in allergic inflammatory processes. Pretreatment of HaCaT cells with PEE suppressed TNF-α/IFN-γ-induced protein and mRNA expression of CCL17 and RANTES. PEE significantly inhibited TNF-α/IFN-γ-induced NF-κB activation. These results suggest that PEE may exert anti-inflammatory responses by suppressing TNF-α and IFN-γ-induced activation of NF-κB in the keratinocytes and might be a useful tool in therapy of skin inflammatory diseases.