Expression of Ventral Diencephalon-Enriched Genes in Zebrafish
DEVELOPMENTAL DYNAMICS
Authors: Li, Sen; Yin, Min; Liu, Shuxi; Chen, Yi; Yin, Yanqing; Liu, Tingxi; Zhou, Jiawei
Abstract
Dopaminergic (DA) neurons in the vertebrate di- and mesencephalon play essential roles in movement control, endocrine modulation and many other important physiological activities. To identify genes that may regulate the specification and differentiation of diencephalic DA neurons in zebrafish, the spatial and temporal expression pattern of a set of genes was investigated. In situ hybridization analysis revealed that expression of DNA binding inhibitor 3 (Id3), early B cell factor 2 (Ebf2), Ebf3, Iroquois related homeobox 1 (Irx1), Kruppel-like factor 7 (Klf7), mab-21-like 1 (Mab21l1), fatty acid binding protein 7 (Fabp7) and stathmin-like 4 (Stmn4), were enriched in the diencephalon of zebrafish. Among these genes, Id3 was expressed specifically in a subset of DA neurons in the ventral diencephalon, with co-expression of neurogenin1 (Ngn1). Alteration of expression levels of Id3 inhibited maturation of developing DA neurons. Taken together, our study provides genetic characteristics of DA neurons in the diencephalon of zebrafish. Developmental Dynamics 239:3368-3379, 2010. (C) 2010 Wiley-Liss, Inc.
Role of trace boron in the microstructure modification and the anisotropy of mechanical and wear properties of the Ti6Al4V alloy produced by electron beam freeform fabrication
VACUUM
Authors: Wang, Han; Yao, Zhengjun; Tao, Xuewei; Zhang, Shasha; Xu, Dongheng; Oleksandr, Moliar
Abstract
This study focused on the effects of trace boron on the microstructure of the electron beam freeform fabricated (EBF3-ed) Ti6Al4V alloy. The anisotropic compression properties and wear behave or were systematically studied, and results indicate that TiB whiskers align in parallel in the longitudinal (Z) direction with trace boron addition. The boron addition enhances the compression strength of Ti6Al4V alloy but the highly directional TiB whiskers lead to the anisotropy of compressive strength. The higher compressive strength can be obtained when the orientation of TiB whiskers is parallel to the load. Besides, trace boron addition improves the wear resistance of Ti6Al4V. Because of the unidirectional alignment of TiB whiskers, the Ti6Al4V-0.07B samples show anisotropy in their wear properties. This study reveals the effect of trace boron on the compression and wear anisotropy of boron-modified Ti6Al4V alloy prepared by EBF3, which is beneficial to its practical application.