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Austenite Grain Growth Behavior of 30BF Steel Before Rough Rolling
Yong‑feng Chen,Jian‑bo Xie,Yan‑xin Wu,Jian‑xun Fu 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4
To investigate the eff ect of heat treatment on the grain size of austenite in 30BF steel, the comparisons of the morphologiesand sizes of austenite grains between heating samples were made with a high-temperature electric resistance furnace, andthe austenite growth models were built with method of mathematics. The results show that most grains in original specimenwith the sizes below 70 μm uniformly distributed. At a heating rate ( v ) of 10 °C/s, the grain size ( d ) value under a certain time( t ) increased by 60–100 μm with raising temperature ( T ) from 850 to 1100 °C, whereas the d value under a certain T merelyincreased by 70–120 μm with raising time to 60 min. Under v = 0.1 °C/s, T = 850 °C, and t = 0 s, the occupied ratio of grainswith sizes of 40–50 μm was 0.165, whereas at 900 °C, the occupied ratio was 0.125. The evolutions of ln (d5.8− d5.80 ) with1/ T were in negative linear correlations, whereas the ln (d5.8− d5.80 ) with ln t were in positive linear correlations. To sum up,the grain growth behavior of steel was elucidated.
TSA Inhibit in Prolonging GVBD which Results Artificial Control of Oocytes Maturation Time
Yong-Xun Jin,Xing-Wei Liang,Sung-Hyun Lee,Xiang-Shun Cui,Nam-Hyung Kim 한국동물번식학회 2012 Reproductive & Developmental Biology(Supplement) Vol.36 No.2s
Although evidences showed that histone deacetylation plays an important role in the mitotic and meiotic cell cycle, but the mechanisms are still unclear. Level of histone acetylation can be easily changed by deacetylase inhibitors (HDACi) i.e trichostatin A (TSA) and valporic acid. In this study, we determined whether the inhibition of histone deacetylation by TSA could affect porcine oocyte maturation and aging process. Our results showed that treated COCs with 100 nM TSA significantly increase the GVBD in each time group than 0, 5, 50 nM but no significantly different from that of higher concentration (200 nm or 300 nM). No significant differences on maturation, blastocyst development, MAPK pattern and expressions of apoptosis gene when treated oocytes with 100 nM TSA for the first 24h of IVM compared with control and 5, 50 nM TSA. However, in the oocytes treated with 200 nM and 300 nM TSA for first 24 h, MAPK significantly decreased and abnormal spindle were observed. But, in prolonged (64 h) of TSA treated group has no significantly different in control. Another data observed that after 24h TSA-treat to prolonged group were significantly decreased of MAPK activation and normal spindle than the other group. We concluded that TSA played a critical role in meiotic progression in porcine oocytes through the regulation of arrest GVBD, which prolonging the in vitro maturation time, but unaffected the subsequent pre-implantation embryo developmental potential and embryonic qualities. Moreover, the histone deacetylase inhibitor TSA may artificially control porcine oocyte maturation time and delay porcine oocyte aging process.
Ko, Yong-Hyun,Kwon, Seung-Hwan,Ma, Shi-Xun,Seo, Jee-Yeon,Lee, Bo-Ram,Kim, Kyungin,Kim, Sun Yeou,Lee, Seok-Yong,Jang, Choon-Gon Elsevier 2018 Brain research bulletin Vol.142 No.-
<P><B>Abstract</B></P> <P>Daidzein is one of the dietary isoflavones present in soybean-based products. After ingestion, daidzein is bioconverted into its major metabolite, 7,8,4’-trihydroxyisoflavone (THIF). Given the pharmacological importance of daidzein, 7,8,4’-THIF has also attracted the interest of researchers. However, there are no reports on the effects of 7,8,4’-THIF on cognition and memory with regard to the cholinergic system. Therefore, this study sought to evaluate the memory-enhancing effects of 7,8,4’-THIF in mice. Treatment with 7,8,4’-THIF ameliorated the cognitive impairments induced by scopolamine, a muscarinic acetylcholine receptor antagonist, in the Y-maze and passive avoidance tests. Interestingly, 7,8,4’-THIF treatment also improved cognitive function in normal mice. This treatment was also able to reverse acetylcholinesterase (AChE) and thiobarbituric acid reactive substance (TBARS) activities in the hippocampus. Finally, 7,8,4’-THIF significantly increased the expression levels of the following molecules in the hippocampus: brain-derived neurotrophic factor (BDNF); phospho extracellular signal-regulated kinase (ERK); phospho cAMP response element binding (CREB); and choline acetyltransferase (ChAT). Our data suggest that 7,8,4’-THIF, a metabolized product of daidzein, improves cognitive function by activating the cholinergic system and the BDNF/ERK/CREB signaling pathway in mice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 7,8,4’-Trihydroxyisoflavone (THIF) improved cognitive and memory function in mice. </LI> <LI> 7,8,4’-THIF restored the hippocampal cholinergic dysfunction and oxidative damage. </LI> <LI> 7,8,4’-THIF enhanced BDNF signaling pathway in the hippocampus of mice. </LI> </UL> </P>
Cat fertilization by mouse sperm injection
Jin, Yong-Xun,Cui, Xiang-Shun,Yu, Xian-Feng,Lee, Sung-Hyun,Wang, Qing-Ling,Gao, Wei-Wei,Xu, Yong-Nan,Sun, Shao-Chen,Kong, IL-Keun,Kim, Nam-Hyung Cambridge University Press 2012 Zygote Vol.20 No.4
<B>Summary</B><P>Interspecies intracytoplasmic sperm injection has been carried out to understand species-specific differences in oocyte environments and sperm components during fertilization. While sperm aster organization during cat fertilization requires a paternally derived centriole, mouse and hamster fertilization occur within the maternal centrosomal components. To address the questions of where sperm aster assembly occurs and whether complete fertilization is achieved in cat oocytes by interspecies sperm, we studied the fertilization processes of cat oocytes following the injection of cat, mouse, or hamster sperm. Male and female pronuclear formations were not different in the cat oocytes at 6 h following cat, mouse or hamster sperm injection. Microtubule asters were seen in all oocytes following intracytoplasmic injection of cat, mouse or hamster sperm. Immunocytochemical staining with a histone H3-m2K9 antibody revealed that mouse sperm chromatin is incorporated normally with cat egg chromatin, and that the cat eggs fertilized with mouse sperm enter metaphase and become normal 2-cell stage embryos. These results suggest that sperm aster formation is maternally dependent, and that fertilization processes and cleavage occur in a non-species specific manner in cat oocytes.</P>
Jin, Yong-Xun,Zheng, Zhong,Yu, Xian-Feng,Zhang, Jia-Bao,Namgoong, Suk,Cui, Xiang-Shun,Hyun, Sang-Hwan,Kim, Nam-Hyung Cambridge University Press 2016 Zygote Vol.24 No.1
<B>Summary</B><P>The mitochondrial genome is maternally inherited in animals, despite the fact that paternal mitochondria enter oocytes during fertilization. Autophagy and ubiquitin-mediated degradation are responsible for the elimination of paternal mitochondria in <I>Caenorhabditis elegans</I>; however, the involvement of these two processes in the degradation of paternal mitochondria in mammals is not well understood. We investigated the localization patterns of light chain 3 (LC3) and ubiquitin in mouse and porcine embryos during preimplantation development. We found that LC3 and ubiquitin localized to the spermatozoon midpiece at 3 h post-fertilization, and that both proteins were colocalized with paternal mitochondria and removed upon fertilization during the 4-cell stage in mouse and the zygote stage in porcine embryos. Sporadic paternal mitochondria were present beyond the morula stage in the mouse, and paternal mitochondria were restricted to one blastomere of 4-cell embryos. An autophagy inhibitor, 3-methyladenine (3-MA), did not affect the distribution of paternal mitochondria compared with the positive control, while an autophagy inducer, rapamycin, accelerated the removal of paternal mitochondria compared with the control. After the intracytoplasmic injection of intact spermatozoon into mouse oocytes, LC3 and ubiquitin localized to the spermatozoon midpiece, but remnants of undegraded paternal mitochondria were retained until the blastocyst stage. Our results show that paternal mitochondria colocalize with autophagy receptors and ubiquitin and are removed after <I>in vitro</I> fertilization, but some remnants of sperm mitochondrial sheath may persist up to morula stage after intracytoplasmic spermatozoon injection (ICSI).</P>